What’s the Role of 3D Printing in Embedded Systems?

Experts Weigh In

3D printing has gone from being a technology on the outskirts of embedded system design, to one that’s becoming a common tool for many design teams. On one hand people are crafting 3D printed enclosures of electronic systems—either for prototyping or end use. On the other hand, the idea of embedding electronic circuitry within 3D printed materials has gained momentum. To gather insights on these technology and design trends, I spoke with expert representatives from four innovative companies in the 3D printer business.

By Jeff Child, Editor-in-Chief

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Mark Norfolk, President, Fabrisonic
www.fabrisonic.com

JEFF CHILD: 3D printing has evolved into a key technology for the design and development of embedded electronics-based systems. What do you see as the important trends today along those lines?

Mark Norfolk

MARK NORFOLK: Historically, electronics embedded using 3D printing has been relegated to embedding wires or 3D printed conductors in a 3D printed polymer. Recent advancement in solid state metal 3D printing has enabled engineers to now bury electronics into metal 3D printed components. Ultrasonic Additive Manufacturing (UAM) is a 3D metal printing technology that uses high frequency ultrasonic vibrations to scrub metal foils together layer by layer as opposed to using a directed energy heat source (for example, laser, e-beam and so on). Ultrasonic joining is a solid state (no melting) process, which enables direct integration of temperature sensitive components into the 3D metal part unlike fusion based processes. The low temperature nature allows sensors, communication circuits and actuators to be embedded into fully dense metallic structures for lasting security and reliability.

To embed electronics into a metal part, a channel or chamber is cut during the CNC stage of the UAM process. The electronic sensor or circuit is then placed into the void and consolidated with the additive stage. In the case of sensors, metal flow in the UAM process creates a strong mechanical joint between the matrix and sensor material, which in turn enables excellent strain transfer to the metal matrix for stress and temperature measurements (Figure 1).

Figure 1
(a) Fiber optic strain gauge embedded in an aluminum bracket using metal 3D printing. (b) CT scan of embedded fiber optic

A flat roof can be created over control circuitry allowing for a small air gap that can be potted or sealed. This allows high power electronics to be buried into a copper or aluminum box for high thermal conductivity. Furthermore, 3D printing allows for cooling channels to be printed surrounding the individual high-power components (Figure 2).

Figure 2
(a) Packaging concept using metal 3D printing and electronic 3D printing.
(b) Integrated electronics in a custom thermal shroud

J.C.: What have been some of the important trends and capabilities in 3D printing materials as they relate to electronic systems?

NORFOLK: For Fabrisonic, a significant portion of recent work has been in engineered materials for the interface between electronics and 3D printed metal. For instance, coefficient of thermal expansion (CTE) mismatch is an ever-present problem in traditional manufacturing. Ultrasonic welding allows printing of dissimilar metals in the same part. Thus, a gradient of CTEs can be printed through thickness in a cooling device. Fabrisonic has worked with materials such as molybdenum and invar to address the CTE gap. Similarly layers of heavy metals such as tantalum and tungsten have been integrated into 3D printed structures for radiation hardening (Figure 3).

Figure 3
Layers of tantalum printed in an aluminum laminate for radiation hardening

J.C.: How have 3D printers used by electronic system developers changed in the past couple years? What changes and advances do you see within the next couple years?

NORFOLK: Electronic system developers have a growing toolbox of 3D printing options. As any specific traditional manufacturing method cannot hope to make every electronics package, similarly no one 3D printing technology can meet every need. New tools are coming on the market as existing tools evolve to meet the needs of industry. Future improvements in 3D printed electronics will surely include:

• Better conductive inks that have lower resistance
• Integration of multiple 3D printing processes into a single production machine. For instance, technologies such as Aerosol Jet could be integrated into a UAM system to print electronics into a 3D printed metal part all in one integrated system
• Automated methods for inserting conventional electronics (wires, chips and such) into 3D printed builds live during the print job
• New electronic designs that take advantage of 3D printing’s ability to integrate in three dimensions

J.C.: We’ve talked in general so far about technology trends in 3D printing? What’s an example of a Fabrisonic system that exemplifies those trends in action?

NORFOLK: All of Fabrisonic systems are capable of embedding electronics. UAM is ultrasonic welding on a semi-continuous basis where solid metal objects are built up to a net three-dimensional shape through a succession of welded metal tapes. Through periodic machining operations, detailed features are milled into the object until a final geometry is created by removing excess material. Figure 4 shows a rolling ultrasonic welding system, consisting of two 20,000 Hz ultrasonic transducers and the welding sonotrode.

Figure 4
Shown here is a SonicLayer 4000 metal 3D printer based off a traditional 3-axis CNC mill. The ultrasonic “weld head” is another tool in the tool changer and can be swapped at any point for a traditional end mill. The additive “weld head” is used to print parts near net shape, while the CNC stage is used to mil to exact tolerances and to create internal voids for embedding electronics.

High-frequency ultrasonic vibrations are locally applied to metal foils, held together under pressure, to create a weld. The vibrations of the transducer are transmitted to the disk-shaped welding sonotrode, which in turn creates an ultrasonic solid-state weld between the thin metal tape and the substrate. The continuous rolling of the sonotrode over the plate welds the entire tape to the plate. Successive layers are welded together to build up height. This process is then repeated until a solid component has been created. CNC contour milling is then used to achieve required tolerances and surface finish.
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Clément Moreau, CEO and Co-Founder, Sculpteo
www.sculpteo.com

JEFF CHILD: What is your perspective on where 3D printing technology is today in terms of its application in electronic systems?

Clément Moreau

CLÉMENT MOREAU: 3D printing has been used to produce prototypes of enclosures of electronic systems for decades—and now longer and longer series of such enclosures. We have a growing number of customers using additive manufacturing to produce their final product up to tens of thousands of parts. This delays the costly and painful re-industrialization process of moving to mass manufacturing. Printing a full electronics circuit system—like a computer or a phone—is still really far away. But we see some application with 3D printed electronics for simple functions like powering LEDs, wiring a sensor and so on.

J.C.: When it comes to 3D printed electronics, what do you see as the most important aspect of that capability?

MOREAU: For 3D printed electronics, conductivity is key. The capability to print selectively using materials with high conductivity is progressing.

J.C.: Sounds like you’re optimistic about where the technology is heading. How do you see 3D printing advancing over the next couple years?

MOREAU: 3D printers are definitely evolving in terms of resolution and of versatility in materials. Still, the main use of 3D printing in this context is printing electronic devices enclosure. The ability to print in fire-resistant materials important is very important, for the electrical certification of devices.

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Alexander Crease, Application Engineer, Markforged
www.markforged.com

JEFF CHILD: As an application engineer, what’s your perspective on the role 3D printing plays in the design and development of embedded electronics-based systems?

Alexander Crease

ALEXANDER CREASE: Overall, 3D printing has made it easier for anyone—whether you’re an engineer, designer, artist or manufacturer—to make things. Creating physical models used to be difficult. Either you’d have to pay thousands of dollars and wait weeks for parts to come in, or you’d need to piece something together with what you have on hand. Either way, manufacturing was a large roadblock—especially with multiple prototypes or iterations in the product development cycle. 3D printing has changed all that—serving as a catalyst for simplified production of parts.

With regard to electronic systems, 3D printing suddenly makes prototyping, testing and iteration much more efficient and makes it easier to create custom components. A large part of embedded electronics is its integration into its hardware—the system integration. Alan Rencher, CEO of Media Blackout, uses Markforged 3D printers to print custom TV and media equipment and sees high value in the printers. He says “Even on finished products that we used to have machined, if we need a part that is too expensive or physically not able to be manufactured, we can use the printer to make those parts.” The quick turnaround time and low cost of 3D printing means end-use parts are incredibly affordable to create. You can go through multiple iteration cycles in days, improving your product’s function and performance all while cutting costs. There’s also the design freedom inherent to additive manufacturing that allows you to incorporate your electronics into your product seamlessly. Both of those combined mean that—whether you’re working on a prototype or a custom end-use part—you can use 3D printing to create a professional, seamless and efficient integrated system.

J.C.: Everyone says that the capabilities of 3D printing are tied to the kinds of materials with which they can print. How do you see that aspect of 3D printing?

CREASE: 3D printing materials have only increased in strength and quality. With innovations like Continuous Fiber Fabrication (CFF), 3D printing has expanded from rough ”looks-like” mockups and prototypes to end-use applications, where durable, long lasting parts are needed. These types of high-strength composite materials mean that the critical parts for your electronics housings, fixtures and frames are strong, cost-effective and easy to make. Many electronics companies now turn to high-strength 3D printing to create strong, lightweight setups for their equipment. For example, Radiant Images developed a 360-camera rig (Figure 5) using a Markforged 3D printing system and saw 63% weight savings and 77% manufacturing time savings when compared to its previously machined counterpart. And it functions just the same.

Figure 5
Radiant Images developed this 360-camera rig using a Markforged 3D printing system and saw 63% weight savings and 77% manufacturing time savings when compared to its previously machined counterpart.

J.C.: It’s clear that the circle of people comfortable using 3D printers keeps getting wider. What’s behind that trend, and what advances in the future do you see attracting engineers to 3D printing?

CREASE: Until recently, 3D printing has been exclusive to mechanical engineers and technicians who know how to design for, operate and repair the machines. Today, a lot of the major improvements to printing we see are in a printer’s ease-of-use. You no longer have to be a trained professional to understand how it all works. It’s getting easier and easier for anyone to design the parts they need, load them into 3D printing software and hit go—then have a part ready in hours.

Looking forward, design optimization for 3D printing has been a growing trend. 3D design software can help engineers design parts that are optimized for the printing process. This not only makes printing even more accessible, but also allows for performance optimization of the parts you need. The introduction of powerful software tools that do the design thinking for you to make parts lighter, stronger, and more effective is something many engineers will be able to take advantage of to create high-performance designs right off the bat. That paves the way for more creativity and innovation in product design.

J.C.: Can you describe some of the details of your company’s Markforged X7 3D printing system?

Figure 6
The Markforged X7 3D printing system includes a sensor suite of that automatically calibrates the machine before each print—leveling the bed, calibrating the nozzles and more. That means there’s no need for a lot of the regular maintenance tasks required of typical 3D printers

CREASE: The Markforged X7 is the top-of-the-line model of our Industrial Series. Both the printer and the parts it delivers are reliable and robust (Figure 6). And the system itself is designed to be low-maintenance and easy to use. The X7 includes a sensor suite of that automatically calibrates the machine before each print—leveling the bed, calibrating the nozzles and more—meaning there’s no need for a lot of the regular maintenance tasks required of typical 3D printers. It prints in a broad range of high strength composite materials, including Kevlar, Fiberglass and Carbon Fiber. Customers can expect high-quality, metal strength parts produced on a low-maintenance workhorse.

 

 

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Simon Fried, President and Co-Founder, Nano Dimension
www.nano-di.com

JEFF CHILD: From your point of view, how do you see the state-of-the-technology when it comes 3D printed electronics?

Simon Fried

SIMON FRIED: The intersection of additive manufacturing and printed electronics offer several opportunities for new or improved ways of making things. The applications that lend themselves to this confluence of technologies cover a spectrum ranging from new ways of adding electronics to larger mechanical parts to—at the other end in terms of size—approaches to challenges confronting the component, semiconductor and electrical packaging industries. The larger scale applications include printing wiring and/or strain gauges into larger mechanical parts and so allow for the elimination of bulky wiring harnesses and connectors, as well enabling better preventative maintenance sensing.

Antennas can also be added to pre-existing parts to open the door to new ways of adding smarts to nose-cones in aircraft or missiles for example. At the other end of the scale spectrum are PCB, component or even wafer level applications. Additive manufacturing of multi-layer circuits or MIDs (molded interconnect devices) means these types of item can both be prototyped much more quickly, secretly and flexibly. They can also be designed differently given the novel non-planar geometries that an additive approach makes possible. At this higher resolution end of the additive electronics space, systems can also be found that can make the embedding of components within a 3D printed circuit an option.

J.C.: What do you see as some of the critical capabilities in 3D printing materials as they relate to electronic systems?

FRIED: Just as is the case in the traditional 3D printing space, it’s materials that set the boundaries of what can be made by way of additive manufacturing of electronics. The first key capability is the development of conductive materials that can be reliably deposited by means of extrusion, aerosol or jetting. Conductive polymers that may contain metals, graphene, carbon nano-tubes and other exotic materials offer lower levels of conductivity for FDM (fused deposition modeling) filaments. More conductive, often nanoparticle-based, inks can be deposited by aerosol or inkjet based additive systems. As these materials become easier to process, cheaper and more conductive, their application set continues to grow, including antennas for example.

For truly 100% additive printing of electronics, it is also necessary to deposit an insulating dielectric material. The traditional electronics industry has a dizzying array of such materials to choose from, each with specifications for a defined performance. While 3D printers don’t yet have materials matched to every need—whether mechanical, thermal or electrical— over the last few years more dielectric materials have become available. Specific inks for specific dielectric performances are now available, where before printers had to make do with whatever polymer was printable. As the set of materials expands so will the applications that an additive approach makes possible.

J.C.: What advances do you see with 3D printing in the next couple years? Is 3D printing as a mainstream, electronics manufacturing technology in sight?

FRIED: It is still early days in the evolution of this technology and as a result most of the work that we are aware of has been experimental and very much lab-based. Considering the amount of development in this space—being driven by the needs of industries as diverse as automotive, defense, medical, consumer electronics, contract manufacturing and many more—it’s highly likely that that such high definition functional 3D printing will start to deliver manufacturing solutions in addition to today’s prototyping and experimental work.

J.C.: Do you have an example of a Nano Dimension 3D printer product that illustrates the kinds of technology trends we’ve been discussing?

Figure 7 The DragonFly Pro can be used to print traditional planar circuits and antennas as well as to print non-planar designs.

FRIED: Nano Dimension’s focus is on delivering solutions to the challenges and opportunities of electrical and product designers. There are several benefits that additive manufacturing approaches can offer, including namely time compression, secrecy, customization and innovation acceleration in general. Our new DragonFly Pro 3D printer is a precision additive manufacturing tool that simultaneously deposits two very different materials, metal and polymer inks. The DragonFly Pro can be used to print traditional planar circuits and antennas as well as to print non-planar designs (Figure 7). It’s the beginning of an entirely new way of making things, as well as a route to making what is currently unmakeable by any other approach. …

See the article in the November 340 issue of Circuit Cellar

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Note: We’ve made the October 2017 issue of Circuit Cellar available as a free sample issue. In it, you’ll find a rich variety of the kinds of articles and information that exemplify a typical issue of the current magazine.

3D Tool Strengthens Marriage of PCB Design with Mechanical Design

Cadence Design Systems has announced its Cadence Sigrity 2018 release, which includes new 3D capabilities that enable PCB design teams to accelerate design cycles while optimizing cost and performance. According to the company, a 3D design and 3D analysis environment integrating Sigrity tools with Cadence Allegro technology provides a more efficient and less error-prone solution than current alternatives using third-party modeling tools, saving days of design cycle time and reducing risk.

In addition, a new 3D Workbench methodology bridges the gap between the mechanical and electrical domains, allowing product development teams to analyze signals that cross multiple boards quickly and accurately.

Since many high-speed signals cross PCB boundaries, effective signal integrity analysis must encompass the signal source and destination die, as well as the intervening interconnect and return path including connectors, cables, sockets and other mechanical structures.

Traditional analysis techniques utilize a separate model for each piece of interconnect and cascade these models together in a circuit simulation tool, which can be an error-prone process due to the 3D nature of the transition from the PCB to the connector. In addition, since the 3D transition can make or break signal integrity, at very high speeds designers also want to optimize the transition from the connector to the PCB or the socket to the PCB.

According to the company, the Sigrity 2018 release enables designers to take a holistic view of their system, extending design and analysis beyond the package and board to also include connectors and cables. An integrated 3D design and 3D analysis environment lets PCB design teams optimize the high-speed interconnect of PCBs and IC packages in the Sigrity tool and automatically implement the optimized PCB and IC package interconnect in Allegro PCB, Allegro Package Designer or Allegro SiP Layout without the need to redraw.
Until now, this has been an error-prone, manual effort requiring careful validation. By automating this process, the Sigrity 2018 release reduces risk, saves designers hours of re-drawing and re-editing and can save days of design cycle time by eliminating editing errors not found until the prototype reaches the lab. This reduces prototype iterations and potentially saves hundreds of thousands of dollars by avoiding re-spins and schedule delays.

A new 3D Workbench utility available with the Sigrity 2018 release bridges the mechanical components and the electronic design of PCB and IC packages, allowing connectors, cables, sockets and the PCB breakout to be modeled as one with no double counting of any of the routing on the board. Interconnect models are divided at a point where the signals are more 2D in nature and predictable. By allowing 3D extraction to be performed only when needed and fast, accurate 2D hybrid-solver extraction to be performed on the remaining structures before all the interconnect models are stitched back together, full end-to-end channel analysis can be performed efficiently and accurately of signals crossing multiple boards.

In addition, the Sigrity 2018 release offers Rigid-Flex support for field solvers such as the Sigrity PowerSI technology, enabling robust analysis of high-speed signals that pass from rigid PCB materials to flexible materials. Design teams developing Rigid-Flex designs can now use the same techniques previously used only on rigid PCB designs, creating continuity in analysis practices while PCB manufacturing and material processes continue to evolve.

Cadence | www.cadence.com

Tool Environment Upgrade Boosts Efficiency of Multi-Board PCB Designs

The latest release of Zuken’s system-level PCB design environment, CR-8000, includes several enhancements aimed at ensuring performance, quality and manufacturability. The CR-8000 family of applications spans the complete PCB engineering lifecycle: from system level planning through implementation and design for manufacturability. The CR-8000 environment also supports 3D IC packaging and chip/package/board co-design.

The focus of CR-8000 2018 is on enabling efficient front-loading of design constraints and specifications to the design creation process, coupled with sophisticated placement and routing capabilities for physical layout. This will increase efficiency and ensure quality through streamlined collaboration across the PCB design chain.
Front-loading of design intent from Design Gateway to Design Force has been achieved by adding an enhanced, unified constraint browser for both applications. This enables hardware engineers to assign topology templates, modify differential signals and assign clearance classes to individual signals. Using a rule stack editor during the circuit design phase, hardware engineers can now load design rules that include differential pair routing and routing width stacks directly from the design rule library into their schematic. Here they can modify and assign selected rules for improved cross talk and differential pair control. Finally, an enhanced component browser enables component variants to be managed in the schematic, and assigned in a user-friendly table.

Manual routing is supported by a new auto complete & route function that layout designers can use to complete manually routed traces in an automated way. Designers also have the option to look for paths on different layers while automatically inserting vias.

A new bus routing function allows layout designers to sketch paths for multiple nets to be routed over dense areas. An added benefit is the routing of individual signals to the correct signal length as per the hardware engineer’s front loaded constraints, to meet timing skew and budgets. If modifications to fully placed and routed boards are required, an automatic re-route function allows connected component pins to remain connected with a simple reroute operation during the move process. In all operations, clearance and signal length specifications are automatically controlled and adjusted by powerful algorithms.

To address manufacturing requirements for high-speed design, the automatic stitching of vias in poured conductive areas can be specified in comprehensive detail, for example, inside area online, perimeter outline or both inside and perimeter. Design-for-manufacturing (DFM) has been enhanced to include checks for non-conductor items, such as silkscreen and assembly drawing placed reference designators. A design rule check will make sure component reference designators are listed in the same order as the parts for visual inspection accuracy.

As many product engineers do not work with EDA tools, intelligent PDF documentation is required, especially in 3D. Design Force now supports creation of PRC files commonly used for 3D printing. The PRC files can be opened in PDF authoring applications such as Adobe Acrobat, where they are realized as a 3D PDF file complete with 3D models and bookmarks to browse the design.

Zuken Americas | us.zuken.com

Siemens Acquires Austemper Design Systems

Siemens has entered into an agreement to acquire Austin, Texas-based Austemper Design Systems, a startup software company that offers analysis, auto-correction and simulation technology. This technology allows customers to test and harden IC designs for functional safety in applications such as automotive, industrial and aerospace systems. These are systems where functional safety and high reliability are mandatory for compliance to safety standards like ISO 26262.

ICs in these applications require three types of functional safety verification: for systemic faults, malicious faults and random hardware faults. Mentor’s existing Questa software (shown) is a leading technology for functional verification of systemic faults and provides solutions for verification of malicious faults for IC security. The software technology from Austemper adds state-of-the-art safety analysis, auto-correction and fault simulation technology to address random hardware faults. This is expected to complement Mentor’s existing functional safety offerings including its Tessent product suite and Veloce platform.

Design teams at leading semiconductor and IP companies use Austemper’s innovative technology to analyze the registered-transfer level (RTL) code versions of their designs for faults and vulnerabilities. It can automatically correct and harden vulnerable areas, subsequently performing fault simulation to ensure the design is hardened and no longer susceptible to errors. Moreover, the Austemper technology performs simulation at orders of magnitude faster than competing solutions.

Siemens will integrate Austemper’s technology into Mentor’s IC verification portfolio as part of Siemens’ larger digitalization strategy, leveraging Siemens’ world-wide sales channel to make this functional safety solution available to companies developing digital twins of safety-critical systems at the heart of autonomous vehicles, smart cities and industrial equipment in Factory 4.0.

Mentor, A Siemens Business | www.mentor.com

EMC Analysis During PCB Layout

Catch Issues Earlier

If your electronic product design fails EMC compliance testing for its target market, that product can’t be sold. That’s why EMC analysis is such an important step. In this article, Craig shows how implementing EMC analysis during the design phase provides an opportunity to avoid failing EMC compliance testing after fabrication.

By Craig Armenti,
Mentor, A Siemens Business

Electromagnetic Compatibility (EMC) is generally defined as the ability of a product to function in its environment without introducing electromagnetic disturbance. EMC compliance is a necessary condition for releasing products to market. Simply stated, if a product does not pass EMC compliance testing for the target market, the product cannot be sold. Regulatory bodies around the world define limits on the radiated and conducted emissions that a device is allowed to produce. Automotive and aerospace manufacturers can set even stricter standards for their suppliers. Design teams are well aware of the importance of ensuring their product is EMC compliant. All that said, many do not attempt to perform EMC analysis during design.

There is a perception that EMC analysis during PCB layout can be a time-consuming task that is challenging to set up and properly configure, with difficult-to-interpret results. Historically, the focus of analysis during design has been on Signal Integrity (SI) and Power Integrity (PI). Manual EMC “analysis” typically is performed post-fabrication, based on the results of testing the actual product. What is often overlooked is that implementing EMC analysis during the design phase provides an opportunity to avoid failing EMC compliance testing after fabrication.

Figure 1
EMC analysis implemented during PCB layout

The current generation of ECAD tools offers EMC analysis functionality that is easy to use, with well-documented rule checks that often include an explanation for each principle and advice on how to address issues. Implementing EMC analysis at appropriate points during PCB layout, prior to fabrication, can mitigate the need for redesign(s) that affect both product development cost and overall time to market (Figure 1).

EMC Simplified

EMC can be a confusing topic, especially for new engineers and designers or those not well versed in the subject matter. Furthermore, there is often confusion as to the difference between electromagnetic compatibility (EMC) and electromagnetic interference (EMI). Although this article is not intended to be an in-depth tutorial on EMC and EMI theory, a quick review of the definitions is appropriate.
As previously stated, EMC is generally defined as the ability of a product to function in its environment without introducing electromagnetic disturbance. Specifically, the product must:

• Tolerate a stated degree of interference
• Not generate more than a stated amount of interference
• Be self-compatible

EMI is generally defined as disturbance that affects an electrical circuit, due to either electromagnetic induction or electromagnetic radiation.

To further simplify the two definitions: EMC is how vulnerable the product is to the environment, and EMI is what the product introduces into the environment (Figure 2).

Figure 2
The four basic EMC/EMI coupling mechanisms relative to the source and victim

The complexity of the topic contributes to the perception that implementing EMC analysis during PCB layout can be a time-consuming task that is challenging to set up and properly configure, with results that are difficult to interpret. The alternative, however, foregoing automated in-design analysis and waiting to test the actual product post-fabrication, has the potential to be significantly more time consuming and costly. Although EMC test labs are not required to provide the average EMC testing pass rate, several studies suggest that the first time pass rate is approximately 50%. Furthermore, EMC compliance failure has been cited as the second cause for redesigns in the automotive industry. Given that an EMC failure will require one or more redesigns that affect both product development costs and overall time to market, performing EMC analysis during PCB layout (designing for EMC compliance) is essential.

Left-Shift to Layout

The term “left-shift” within the engineering space is often used to describe the act of moving (or shifting) a task that would normally occur toward a later phase of the design process, to occur also during an earlier phase. . …

Read the full article in the July 336 issue of Circuit Cellar

Mentor | www.mentor.com

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PCB Design Tools Evolve to Next Level

More Smarts, Wider Scope

PCB design tools and methods continue to evolve as they race to keep pace with faster, highly integrated electronics. Automated, rules-based chip placement is getting more sophisticated and tools are addressing the broader picture of the PCB design process.

By Jeff Child

Diagnostic fter decades of evolving their PCB design tool software packages, the leading tool vendors have the basics of PCB design nailed down—auto-routing, complex layer support, schematic capture and so on. In recent years, these companies have continued to come up with new enhancements to their tool suites, addressing a myriad of issues related to not just the PCB design itself, but the whole process surrounding it.

With that in mind, even in the last sixth months, PCB tool vendors have added a whole host of new capabilities to their offerings. These include special reliability analysis capabilities, sophisticated design-for-test (DFT) tools, extended team collaboration support and more.

High-Speed Signal Validation

Exemplifying these trends, in February Mentor Graphics started shipping its HyperLynx solution that provides automated and intelligent channel extraction for serializer/deserializer (SerDes) interfaces. HyperLynx PCB simulation technology for high-performance designs provides an end-to-end fully automated SerDes channel validation solution. Today’s advanced electronics products require intelligent high-speed design tools to ensure that designs perform as intended. With signaling rates of
50 Gbps becoming commonplace, and protocols like Ethernet pushing 400 Gbps bandwidth, traditional methods are insufficient. This is crucial for industries that demand superior high-speed performance such as automotive, networking, data centers, telecom and IoT/cloud-based products.

SerDes applies to interfaces like PCI Express (PCIe) that are used anywhere high-bandwidth is required. The problem is today’s hardware engineers lack time to fully understand the detailed signal integrity requirements of these interface protocols and may have limited access to signal integrity (SI) and 3D EM experts for counsel. Mentor’s new HyperLynx release provides tool-embedded protocol-specific channel compliance. The company claims it’s the industry’s first fully automatic validation tool for PCB SerDes interfaces. This includes a 3D explorer feature for design and layout optimization of non-uniform structures like breakouts and vias.

Using the new HyperLynx release, hardware engineers can easily perform protocol-specific compliance checks. The tool provides embedded protocol expertise for PCIe Gen3/4, USB 3.1 and COM-based technology for Ethernet and Optical Implementers Forum (OIF). Engineers can easily perform equalization optimization (CTLE, FFE, DFE) based on protocol architecture and constraints. HyperLynx’s 3D Explorer feature provides channel structure design and pre-layout optimization. Template-based 3D structure synthesis can be used for differential pair, BGA breakouts, via configurations, series-blocking capacitors and more (Figure 1).

Figure 1
Using HyperLynx, a 3D area is automatically created based on the available return path.

This isn’t the first Mentor Graphics time came out with PCB design tools that address a new dimension of PCB design. In March 2017, the company released its Xpedition vibration and acceleration simulation product for PCB systems reliability and failure prediction. The Xpedition product augments mechanical analysis and physical testing by introducing virtual accelerated lifecycle testing much earlier in the design process. The tool lets you simulate during the design process to determine PCB reliability and reduce field failure rates. You can also detect components on the threshold of failure that would be missed during physical testing. Finally, you can analyze pin-level Von-Mises stress and deformation to determine failure probability and safety factors.

DFT Plugin Added

In its most recent enhancement to its PCB tools offering, in February Zuken announced that it teamed up with boundary scan tool vendor XJTAG to add a plugin that enhances Zuken’s CR-8000 PCB Design Suite with a design for test (DFT) capability. . …

Read the full article in the June 335 issue of Circuit Cellar

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Quick Prototyping Solutions

PCB Makers Up Their Game

Today’s embedded systems engineers have a rich variety of PCB quick prototyping resources to get their designs up and running. The PCB production and assembly vendors listed here feature lots of powerful online quoting tools, sophisticated PCB manufacturing expertise and world-class support services.

Accutrace
www.pcb4u.com
Location: Santa Clara, CA
Accutrace serves the electronics industry’s needs for quick turn PCB fabrication from prototype to production. They can manufacture only what is needed, when it’s needed—and in the amount needed. No need to worry about long shelf life or tying up your capital in bare board inventory.
Services: PCB capabilities: Capabilities: Up to 50 layers; any layer HDI; blind and buried vias; 2-mil line width and spacing; copper up to 16 oz. Materials supported: FR4, Rogers, ISOLA, Polymide-flex, Metal core, Taconic and Magtron

Advanced Circuits
www.4pcb.com
Location: Aurora, CO
3rd largest PCB manufacturer in the US. Advanced Circuits also offers exclusive services to help customers with their PCB Projects. Advanced Circuits can help you with all aspects of PCB fabrication—from manufacturing through assembly. It can create rapid prototypes and even provide weekend turns to get you your orders when you need them.
Services: Full spec PCBs, small quantity / quick turn PCBs, custom spec / quick turn PCBs, highly specialized precision PCBs and large scale production. No order is too small or too large.

AP Circuits
www.apcircuits.com
Location: Calgary, Canada
AP Circuits is a quick turn-around manufacturer of custom PCBs. Founded in 1984, AP Circuits became the world’s first facility devoted to affordable rapid printed circuit board prototyping. Over thirty years of experience getting your project done right and delivered on time.
Services: Quick turn PCB fabrication services include: Flex, semi-rigid, Multi-layer to 24 layer at 3 mil with multiple substrate options, laser drilling, blind/buried vias, Boring and countersink, direct metalization, UL/ISO/MIL/RoHS

Beta Layout
uk.beta-layout.com
Loc
ation: Shannon, Ireland
Beta Layout’s PCB-POOL operation is Europe’s largest manufacturer of PCB prototypes, with over 36,000 customers worldwide. PCB-POOL cost sharing principle enables system designers to benefit from low prices. You can calculate the prices instantly online using the PCB-POOL’s Online price calculation. PCBs using special technologies and materials can also be sourced directly from the company, from prototype to series production quantities.
Services: Prototype PCBs or small series PCBs in 1 – 6 working days; Laser-cut SMD-Stencils in 1-3 working days; Fully populated SMD and THT prototype boards in 2 working days; Support for PCBs with embedded UHF RFID modules

Beta Layout has an online pricing calculation tool that lets you unload your Eagle BRD files for 3D vacuolation.

Custom Circuit Boards
www.customcircuitboards.com
Location: Phoenix, AZ
Custom Circuit Boards is a full service quick turn PCB manufacturer located in Phoenix, Arizona with the capabilities to fabricate your prototype and production quantity PCBs. It We specializes in Quick turn PCB services with an industry leading turnaround time as fast as 24 hours. The company also does PCB prototypes, production PCBs and multilayer PCBs.
Services: From 1 to 40 PCB layers; Board material support includes: FR4, Rogers, Polyimide, Teflon, Black FR4, Arlon AR350, Getek Copper Clad Thermal Substrates, Hybrid (Rogers and FR4) BT Epoxy, Nelco 4013, Metal Core Materials

EzPCB
www.ezpcb.com
Location: Shenzhen, China
EzPCB is an online provider of PCB manufacture and PCB assembly products and services. Based in China, the company’s worldwide business has been growing rapidly since its launch in 2004. EzPCB has supplied high quality PCBs—and related products and services—for over 2,000 customers from more than 40 countries. Its customers include amateurs, small businesses, universities and many world-class companies and organizations including Jet Propulsion Laboratory, Micron, Siemens, STMicroelectronics and Rohm.
Services: PCB manufacturing, PCB assembly, cabling, enclosures, keypads, stencils and components, one-stop turnkey services and design consultation

Example of a 12-layer HDI boards with buried and blind vias built by ExPCB.

Epec
www.epectec.com
Location: New Bedford, MA
Epec specializes in custom, build to print electronics. It has a global team of engineers, designers, R & D innovators, product managers, manufacturing/supply chain professionals, quality assurance personnel and sales/customer service staff, all of whom are experts in their fields. Rather than limit its production capacity to its US and UK manufacturing centers, Epec has developed UL certified world class production facilities which are ISO-9001, QS-9002,
TS-16949, with aligned technology roadmaps and quality systems.
Services: Provides complete engineering and design services, from concept through production, in a quick and efficient time frame. Capabilities include: battery pack design and assembly, PCB electronic design, cable assembly design, flex and rigid-flex circuit design, user interface and more.

Imagineering
www.pcbnet.com
Location: Elk Grove Village, IL
Imagineering acts as a reliable source for high quality and on time PCBs. Its quick turn prototypes not just intended for testing and verification of designs. Every one of its boards meet
IPC-A-600 F (Class2) standard, be it prototype or production. Specializes in quick turn prototypes, as well as rapid turn production.
Services: PCB assembly capabilities summary: SMT, Flip chip, thru hole, Flex circuit assembly, cable assemblies, lead-free assembly and sire harness assembly. Full Turnkey service for all customers if needed as well as partial turn-key and consignment orders. PCB capabilities include: 22 layer fabrication, hole sizes down to 8 mil plated and 5 mil laser drilled, 3 mil line width and spacing, 6oz copper and a maximum PCB thickness up to .300″.

MacroFab
www.macrofab.com
Location: Houston, TX
MacroFab’s mission is to create the future of electronics manufacturing through user-centric, cloud-based technology. In October 2017 the company launched its 10-day Prototype turnaround service. This service benefit teams that quickly iterate on designs to finalize to their products.
Services: MacroFab’s software allows you to control and manage your entire PCBA manufacturing from start to finish. You can update your PCB layers and BOMs online, then approve the files for production.

MacroFab lets you upload your product design files directly onto its online platform. You can receive an instant quote and place your order without delays.

OurPCB
www.ourpcb.com
Location: Shijiazhuang Hebei, China
OurPCB is a multi-national PCB manufacturing and PCB assembly company that provides global service and support while using its own Chinese manufacturing capabilities. Company has provided professional PCB production and assembly services for more than 2,500 customers around the globe.
Services: Assembly capabilities include BGA, LGA, QFN, QFP, DIP and SIP. The smallest SMT footprint it can mount is 0201. Factory can also provide programming and wiring as well as injecting and conformal coating services.

PCBCart
www.pcbcart.com
Location: Hangzhou, China

PCBCart is a professional PCB production service provider with more than 10 years of experience in the electronics manufacturing industry. We’ve manufactured printed circuit boards for more than 10,000 companies and over 80 countries around the world. Fast, affordable prototype assembly they take your unique PCB designs, prepare them for the assembly process and perform comprehensive testing to ensure they meet your precise performance requirements. Can provide a complete turnkey PCB prototype assembly featuring a one-stop shop approach.
Services: Development, manufacturing, assembly and testing of custom PBCs; Rapid PCB prototyping; Circuit boards manufacturing: PCB assembly; Components sourcing services

PCB Unlimited
www.pcbunlimited.com
Location: Tualatin, OR
In 2003, PCB Unlimited’s sister company Stencils Unlimited pioneered the internet SMT stencil quote and order process. In 2008, PCB Unlimited took it one step further by providing a one-stop-shop where engineers can quote and order online US and offshore PCB services and everything else they need for their PCB projects.
Services: US PCB fabrication including Rigid, Flex and Rigid-Flex PCBs; Offshore PCB Fabrication; US Quick-Turn Prototype PCB Assembly and Low Volume Production followed by PCB Unlimited’s offshore operation to service your high-volume production needs

Screaming Circuits
www.screamingcircuits.com
Location: Canby, OR
Screaming Circuits, a division of Milwaukee Electronics, was founded in 2003 to reinvent electronics manufacturing. Unlike old-fashioned manufacturing models that focused on mass volumes and cost-control through rigidity, Screaming Circuits specializes in fast and flexible prototype and short-run assemblies. It offers short-run production for higher volumes without forecasts, NRE charges or volume commitments. If you need to go a step further with scheduled production, its parent company Milwaukee Electronics provides a full range of electronics manufacturing services, from original design to volume production and life-cycle management.
Services: PCB fabrication, PCB assembly, parts sourcing, layout engineering, prototype to volume production transitioning

Sierra Circuits
www.protoexpress.com
Location: Sunnyvale, CA
Sierra Circuits is an ISO 9001:2015, ISO 13485:2016 and MIL-spec MIL-PRF-55110 certified, Silicon Valley-based, high-technology PCB manufacturer and assembler. It specializes in quick turn PCBs and medium production. By owning its manufacturing and assembly facilities, the company controls every aspect of the production schedule and quality.
Services: Micro/fine line PCBs, PCB assembly, flexible PCBs, lead-free PCBs, high-reliability PCBs, no-touch PCBs, burn-in PCBs, R&D PCBs, MIL-spec PCBs, PCB design

Sierra Circuits can produce Flex PCBs with flex from 1 to 16 layers.

SlingShot Assembly
www.slingshotassembly.com
Location: Denver, CO
SlingShot Assembly’s state-of- the-art production facility handles prototype and low-volume production orders. From a single board and up, they use the latest software, processes and equipment to produce high-quality assemblies fast and at a reasonable price. Customers use the company’s assembly services for early prototype runs when they need high-quality assemblies completed in a matter of a few days. Typically, the quantities for early prototypes range from a single board to about 50. Once initial testing of early prototypes is completed, many customers move to late-stage prototyping or pre-production assemblies.
Services: Quick turn PCB assembly, standard assembly turn time: 2 – 3 days (turn times as fast as 24 hours available), prototype and low-volume production (single orders welcome, 100% turn-key components, turn-key board fabrication encouraged, test (including flying probe and functional test), conformal coating, limited box build services, web-based BOM sourcing and more.

This article appeared in the May 334 issue of Circuit Cellar

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Device Silences TV Commercials

Arduino-Controlled Solution

Ever wish you could block out those annoying TV ads? Tommy describes in detail how he built a device for easily muting the audio of commercials. His project relies on three modules: a UHF radio receiver, an IR module and an Arduino Trinket board.

By Tommy Tyler

Does your blood start to boil as soon as one of those people on TV tries to sell you precious metals, a reverse mortgage, a miraculous kitchen gadget or an incredible weight reduction plan? Do you want to climb the wall the next time someone says “But wait! Order now and get a second one free . . .“? Believe it or not, there was a time long ago when TV commercials were actually entertaining. That was before commercial breaks evolved from 30 second or one-minute interruptions into strings of a half-dozen or more advertisements linked end-to-end for three to five minutes—sometimes with the exact same commercial shown twice in the same group! What is perhaps most annoying is the relentless repetition.

Historically, all the feeble attempts at TV commercial elimination have been applied to recordings on VCRs or DVRs. Anyone who watches programming that’s best enjoyed when viewed in real-time—news, weather and sports—has probably wished at one time or another for a device that can enable them to avoid commercials. They long for a device that could be inserted between their TV and the program source—whether it be cable, satellite or an OTA antenna—to instantly recognize a commercial and blank the screen, change channels or somehow make it go away. The technology for doing that does exist, but you’ll probably never find it applied to consumer products. Since funding of the entire television broadcast industry is derived from paid advertisements, any company that interferes with that would face enormous opposition and legal problems.

After many years of searching the Internet I’ve concluded it is wishful thinking to expect anyone to market a product that automatically eliminates commercials in real-time. I decided to work instead on the next-best approach I could think of: A device that makes it quick and easy to minimize the nuisance of commercials with the least amount of manual effort possible. This article describes a “Kommercial Killer (KK)” that is controlled by a small radio transmitter you carry with you so it’s easily and instantly accessible. No scrambling to find that clumsy infrared remote control and aim it at the TV when a commercial starts. Just press the personal button that’s always with you, even while remaining warm and cozy curled up under a blanket.

Kommercial Killer

The KK operates from anywhere in the home, even from another room completely out of sight of the TV and can be triggered at the slightest sound of an advertisement, political message, solicitation or perhaps even a telephone call. It works with any brand and model TV without modifications or complicated wiring connections by using the TV’s infrared remote control system. If you get a new TV, its remote control can easily teach KK a different MUTE command. Don’t worry about leaving the room with the TV muted. KK automatically restores audio after a certain amount of time. The default time is three minutes, the length of a typical commercial break, but you can easily configure this to any amount of time you prefer. And when you want to restore audio immediately—for example if you have muted non-commercial program material by mistake or if a commercial runs shorter than expected—just press your transmitter button again.

Figure 1
Schematic of the Kommercial Killer

KK is built mainly from three commercially available modules that do all the heavy lifting (Figure 1). The first module is a miniature UHF radio receiver. The second is an infrared module that can learn and mimic the TV mute signal. The third module is an Arduino Trinket board that provides commercial break timing and overall control. This article explains how to load a small program into that module without needing any special equipment or training, and even if you have absolutely no previous experience with Arduino devices.

The three modules are small and inexpensive ($7 to $10 each) and with just eight additional components KK can be built on an open perf board, strip board or enclosed in a 6-inch3 box. It is powered from the same USB Micro cable you use to load or modify the Arduino program, or from any other available USB port or 5 V charger.

UHF Receiver Module

The best UHF radio transmitters and receivers are all manufactured in China, and there are no major distributors in the U.S. So, order this item early and be prepared to wait about 20 days for delivery. After sampling many different remote controls to evaluate performance, quality, cost and shipment, I selected a product manufactured by the Shenzhen YK Remote Control Electronics Company, whose products are sold and shipped through AliExpress. Shenzhen remote controls use two types of receivers. . …

Read the full article in the May 334 issue of Circuit Cellar

After you’ve read the full article, don’t forget to go the the Article Materials Page for useful links and information.
Don’t miss out on upcoming issues of Circuit Cellar. Subscribe today!
Note: We’ve made the October 2017 issue of Circuit Cellar available as a free sample issue. In it, you’ll find a rich variety of the kinds of articles and information that exemplify a typical issue of the current magazine.

MPU-Based SOM Meets Industrial IoT Linux Needs

Microchip Technology has unveiled a new System on Module (SOM) featuring the SAMA5D2 microprocessor (MPU). The ATSAMA5D27-SOM1 contains the recently released ATSAMA5D27C-D1G-CU System in Package (SiP). The SOM simplifies IoT design by integrating the power management, non-volatile boot memory, Ethernet PHY and high-speed DDR2 memory onto a small, single-sided printed circuit board (PCB). There is a great deal of design effort and complexity associated with creating an industrial-grade MPU-based system running a Linux operating system. Even developers with expertise in the area spend a lot of time on PCB layout to guarantee signal integrity for the high-speed interfaces to DDR memory and PHY while complying with EMC standards.

The SAMA5D2 family of products provides an extremely flexible design experience no matter the level of expertise. For example, the SOM—which integrates multiple external components and eliminates key design challenges around EMI, ESD and signal integrity—can be used to expedite development time. Customers can solder the SOM to their board and take it to production, or it can be used as a reference design along with the free schematics, design and Gerber files and complete bill of materials which are available online. Customers can also transition from the SOM to the SiP or the MPU itself, depending on their design needs. All products are backed by Microchip’s customer-driven obsolescence policy which ensures availability to customers for as long as needed.

The Arm Cortex-A5-based SAMA5D2 SiP, mounted on the SOM PCB or available separately, integrates 1 Gbit of DDR2 memory, further simplifying the design by removing the high- speed memory interface constraints from the PCB. The impedance matching is done in the package, not manually during development, so the system will function properly at normal and low- speed operation. Three DDR2 memory sizes (128 Mb, 512 Mb and 1 Gb) are available for the SAMA5D2 SiP and optimized for bare metal, RTOS and Linux implementations.

Microchip customers developing Linux-based applications have access to the largest set of device drivers, middleware and application layers for the embedded market at no charge. All of Microchip’s Linux development code for the SiP and SOM are mainlined in the Linux communities. This results in solutions where customers can connect external devices, for which drivers are mainlined, to the SOM and SIP with minimal software development.

The SAMA5D2 family features the highest levels of security in the industry, including PCI compliance, providing an excellent platform for customers to create secured designs. With integrated Arm TrustZone and capabilities for tamper detection, secure data and program storage, hardware encryption engine, secure boot and more, customers can work with Microchip’s security experts to evaluate their security needs and implement the level of protection that’s right for their design. The SAMA5D2 SOM also contains Microchip’s QSPI NOR Flash memory, a Power Management Integrated Circuit (PMIC), an Ethernet PHY and serial EEPROM memory with a Media Access Control (MAC) address to expand design options.

The SOM1-EK1 development board provides a convenient evaluation platform for both the SOM and the SiP. A free Board Support Package (BSP) includes the Linux kernel and drivers for the MPU peripherals and integrated circuits on the SOM. Schematics and Gerber files for the SOM are also available.

The ATSAMA5D2 SiP is available in four variants starting with the ATSAMA5D225C-D1M- CU in a 196-lead BGA package for $8.62 each in 10,000 units. The ATSAMA5D27-SOM1 is available now for $39.00 each in 100 units The ATSAMA5D27-SOM1-EK1 development board is available for $245.00.

Microchip Technology | www.microchip.com

Reliability and Failure Prediction: A New Take

HALT methodology has been a popular way to test harsh environment reliability. A new approach involves PCB design simulation for vibration and acceleration for deeper yet faster analyses.

By Craig Armenti & Dave Wiens—Mentor Board Systems Division

Many electronic products today are required to operate under significant environmental stress for countless hours. The need to design a reliable product is not a new concept, however, the days of depending on a product’s “made in” label as an indicator of reliability are long gone. PCB designers now realize the importance of capturing the physical constraints and fatigue issues for a design prior to manufacturing to reduce board failure and improve product quality.

Simulation results should be available in a two-phase post-processor for each simulation, providing broad input on the PCB’s behavior under the defined conditions.

Simulation results should be available in a two-phase post-processor for each simulation, providing broad input on the PCB’s behavior under the defined conditions.

Although every product is expected to fail at some point. That’s inevitable. But premature failures can be mitigated through proper design when proper attention is paid to potential issues due to vibration and acceleration. ….

Read this article in the August 325 issue of Circuit Cellar

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The Perfect PCB Prototype

Interested in constructing perfect PCB prototypes? Richard Haendel has the solution for you. In this article, he explains how five simple steps—print, mount, punch, fit, and evaluate—can save you a lot of time and money.

The following article first appeared in Circuit Cellar 156.


Who designs and builds your prototype circuit boards? The other department? Oh. Well, in that case, nice seeing you. Just flip past this article and enjoy the rest of the magazine.

On the other hand, if you’re a do-it-yourself engineer like me, then perhaps my technique for prototyping prototypes will interest you (see Photo 1). It’s so easy, cheap, and obvious, I have trouble believing that no one else has done it before. If you have, please let me know. I’d love to compare notes. The entire process can be described in five words: print, mount, punch, fit, and evaluate.

Photo 1: It doesn’t get any easier than this (or cheaper). Just remember to print, mount, punch, stuff, and evaluate.

Photo 1: It doesn’t get any easier than this (or cheaper). Just remember to print, mount, punch, stuff, and evaluate.

PRINT

Your printer must be able to print a full-scale, moderately accurate representation of your PCB layout. I say “moderately accurate,” because, after all, a 10% error on a 0.4″-spaced resistor is only 0.04″. That’s close enough for most through-hole designs. Surface mounting, however, can be a problem. But because I don’t normally do surface mounting, it’s not a problem for me.

I use two printers for development: a color ink-jet and a black and white laser-jet. Both are fairly old, but they still have more than enough accuracy for this purpose. The laser-jet is probably a little better, but not by much.

Your printed layout must show (at minimum) the holes and component layout. You may or may not need to see the traces; it depends on what you’re hoping to accomplish. The traces are superfluous for test fitting (e.g., to make sure that components don’t touch each other); however, if you’re building a full-scale concept model, you’ll need as much detail as is practical. In fact, with a little more effort, you could print the top traces on one sheet and the bottom traces on another, glue them to the foam board on opposite sides (taking care to line up the holes, of course), and make yourself a full-scale PCB model. Cool.

MOUNT

Trim the excess white space from the sheet containing your printed image, because it will just get in the way. Next, cut a piece of foam board slightly larger than your layout. A utility knife and metal ruler work well for this. Peel the backing from the foam board’s adhesive side; of course, if you don’t have the self-adhesive kind, simply apply dry glue (from a glue stick) to either the board or paper. After that, carefully position one corner of your image on the foam board and smoothen it. Rub gently but firmly with a soft cloth or paper towel to permanently “seat” the image.

If you get air bubbles or wrinkles, throw it away and start over. Remember, your pattern must be accurate. You can probably make a new one faster than you can fix a damaged one. A little practice goes a long way toward achieving perfect results.

PUNCH

Using a pushpin (or a similar instrument), carefully punch your holes. As you can see in Photo 2, I use metallic pushpins with longer-than-usual shafts. Naturally, the shorter plastic pushpins will work just as well. Thumbtacks, however, are not a good choice; they’re pretty rough on the fingernails.

Photo 2: A small pin is my favorite tool for punching holes in the foam board.

Photo 2: A small pin is my favorite tool for punching holes in the foam board.

Note that this stage can be tedious, especially if you have a large board with many holes. Take your time. The holes should be centered as accurately as possible. Also, don’t push the pin all the way through; it’s merely intended to puncture the paper front so the component’s pins can penetrate the foam and have it “grab” them. In other words, you want a snug fit so the pieces don’t (easily) fall off the board.

That’s how it works for IC sockets and connectors with short leads (i.e., less than the thickness of the board). However, resistors and other parts with longer leads are a different matter. In this case, you must either trim the leads—which is fine if you’re not planning to reuse the component—or extend the hole to the backside with something like a map pin. That’s what I usually do.

FIT

That’s right. Simply fit (or stuff) your components as you would a real circuit board. Components with short leads should be easy to fit; however, those with longer leads may need persuading. Simply insert the part, grab one lead close to the board’s surface with needle-nose pliers, and gently (but firmly) coax it through the hole. Sometimes this can be a pain, especially with small-gauge component leads (e.g., ceramic capacitors). You may need to enlarge the hole from the front or backside. Remember: practice, practice, practice.

EVALUATE

In other words, use it for whatever purpose you need. Most of the time, I make these models just to test my board design and confirm that all parts will fit before committing to a manufactured prototype. After that, it’s trash. If the design is significant (pronounced “expensive to produce”), then I may make others until I’m confident of perfection.

I must confess, though, most of my models are nowhere near as neat and attractive as the one pictured in this article. Frequently, the images are slapped on a piece of scrap foam, tested, and tossed within 5 min. or less.

SO, WHAT’S IT COST?

Not much. Just the other day, I purchased a 20″ × 30″, 3/16″ thick sheet of white self-adhesive foam board at a local hobby store for $4.99. (The nonadhesive type was about $1 less.) Therefore, the cost is $4.99 divided by 600 square inches, or a mere $0.00832 per square inch—that’s less than a penny. At that rate, this board cost only $0.07.

IS IT WORTH IT?

You bet! I’ve caught numerous board design and layout errors with this technique. I’ve also learned that legends on the silk-screen layer don’t always match the physical part as closely as you may expect. This is good to know when you’re tight on board space and need to fudge a little.

Photo 3: Notice that D1 will not actually touch J2, as the PCB layout program’s silkscreen outline indicates.

Photo 3: Notice that D1 will not actually touch J2, as the PCB layout program’s silkscreen outline indicates.

I was able to crowd D1 between J2 and J3, because J2 is 0.08″ smaller than its silkscreen outline (see Photo 3). So, even though D1 appears to touch J2, there’s actually 0.04″ between them, which is more than enough for my design.

So, did I lie? Is this not as simple as can be? And cheap! Try it yourself and see.—By Richard Haendel (Circuit Cellar 156)

Full Schematic and PCB Layout in One Project File

TARGET 3001! combines the full schematic and PCB layout in one project file. Schematic and layout are always in a consistent state. An embedded PSpice simulator enables the modeling of the electrical function of the circuit eliminating errors early in the design phase.

TARGET 3001! offers more than 38,000 components in a local MySql database. When placed on a server, an entire design team can simultaneously access the same component source. If a component is placed in a design, its drawing and all its properties still can individually be changed independent of the database. Most components are furnished with a 3-D model so that a PCB can be easily inspected in a live 3-D view. A STEP file import allows for the creation of custom 3-D models; the STEP export allows the 3-D printing of an exact model of your PCB with components.

Besides XGerber and Excellon, TARGET 3001! provides a wide range of industry standard manufacturing formats. It also includes a tool for isolation milling, outputting the data in G-Code and HPGL. Open and save Eagle projects. PCB sizes up to 47″ × 47″ and an embedded front-panel designer make TARGET 3001! the perfect tool for high-end makers as well as development pros who want to move quickly from design idea to finished product.

You can try a free version for double-sided projects up to 250 pins/pads at: www.target3001.com.

Source: Ing.-Buero FRIEDRICH

21st-Century Electronics Craftsman: Meet Saar Drimer

Saar Drimer (PhD, Cambridge) runs Boldport, a London-based hardware and prototyping consultancy that specializes in circuit boards. Wisse Hettinga recently met with Drimer to discuss PCB design, electronics craftsmanship, and his various engineering projects.

Saar Drimer, electronics craftman

Saar Drimer, electronics craftman

Hettinga writes:

The Art of Electronics is a book that’s well-known by many electronic engineers all over the world. Written by Horowitz and Hill, the first edition was published in 1980 and recently, in 2015, a third edition was released. Over the past 35 years, the book has been an inspiration and resource for many engineers eager to learn about the art of designing with electronics. But there is also a real art of electronics. To discover what that is, I traveled to London to meet up with Saar Drimer. His workplace was in one of the characteristic arches underneath London Bridge Station. With the constant rumble of the trains arriving and pulling out of the station in the background, he showed me some of his work.

SOMETHING COMPLETELY DIFFERENT
Drimer’s designs are completely different from what we usually see on PCBs. Where most of our designs end up as small rectangles with only a few holes for the assembly screws, his boards take different shapes. Some are swirly, sometimes animal-like. At other times, he integrates components right into the board in special holes, as you can see in his Tiny Engineer Superhero Emergency Kit. Often there is no straight copper line to be found; they go all over the place and are a vital part of the total design.

Emergency kit

The Tiny Engineer Superhero Emergency kit

A PCB designed by Drimer asks for exposure and can be interesting for art’s sake only, but also for marketing purposes where drawing attention and presenting a surprise is required. One of his designs even features in the women’s magazine Marie Claire!

DESIGNING THE OTHER WAY AROUND
Where many of us try to put all the PCB and wiring in a (mostly) gray box and leave it out of sight, Drimer is doing exactly the opposite: he is trying to expose it. His end product is the PCB and that is where his art comes into the picture—in many exciting formats. In many ways, Saar is an engineer like many of us. He is extremely knowledgeable about electronics and designing. But when it comes to the latter, he is using unorthodox methods. Where we start with the schematics, Drimer starts with the form and shape of the final PCB—basically, he designs the other way around!

Working and designing in the opposite direction is not easy with existing PCB CAD programs like Eagle or Altium. They all start with a schematic and are using component libraries routing the final layout in the most effective or smallest footprint PCB. Their rigid, straightforward approach is excellent when designing for just another rectangle PCB. But if you want new and creative designs, you need to think of a different way of working and using other tools. If you want to change the way of thinking and designing, you need to be able to use free forms and the routing cannot be left to the CAD program. And that is exactly what Drimer is doing.

THE CRAFTSMAN’S TOOL
To be able to start with a different type of design, Drimer was left with no choice but to start developing his own PCB CAD design program. Unlike most of us who call ourselves “engineer,” Drimer calls himself ”craftsman”—and as a true craftsmen, he makes his own tools. PCBmodE is Drimer’s custom PCB CAD program. The “mod” in PCBmodE has a double meaning, Drimer explained. “The first is short for ‘modern’ in contrast to tired, old EDA tools. The second is a play on the familiar ‘modifications,’ or ‘mods,’ done to imperfect PCBs. Call it ‘PCB mode’ or ‘PCB mod E’, whichever you prefer,” he said.
PCBmodE is a PCB design Python script that creates an SVG from JSON input files. It then creates Gerber (the standard software to describe the PCB images: copper layers, soldering mask, legend, etc.) and Excellon files for manufacturing. With no graphical interface, PCBmodE enables you to place any arbitrary shape on any layer because it is natively vector-based. Most of the design is done in a text editor with viewing and some editing (routing) completed with Inkscape. (Inkscape is a professional vector graphics editor for Windows, Mac OS X, and Linux. It’s free and open source.) On his website, Drimer explains how to work with the program.

“PCBmodE was originally conceived as a tool that enables the designer to precisely define and position design elements in a text file, and not through a GUI. For practical reasons, PCBmodE does not have a GUI of its own, and uses an unmodified Inkscape for visual representation and some editing that cannot practically be done textually,” said Drimer.

A typical PCBmodE design workflow is as follows:

  • Edit JSON files with a text editor
  • “Compile” the board using PCBmodE
  • View the generated SVG in Inkscape
  • Make modifications in Inkscape
  • Extract changes using PCBmodE
  • Back to step 1 or step 2
  • Generate production files using PCBmodE

If you want to give PCBmodE a try, simply download it at www.pcbmode.com. It works with Linux, but Drimer is interested in results on other OS platforms as well. For starters, a “hello solder” design is currently available.

Hello Solder

Starter example: Hello Solder

THE CRAFTSMAN’S WORK
Examples of Drimer’s work are posted on his website, www.boldport.com. I especially like the Tiny Engineer Superhero Emergency Kit’ design where the components are integrated into the PCB itself resulting in a very flat design. You will also notice he is not using straight lines and angles for the traces. It is more of a pencil drawing; the traces flow along the lines of the PCB and components.

You might ask why on earth someone would put so much effort into all of this? Don’t ask! But, if you like, here are a few answers. First, because it is an art. Second, it is Drimer’s full-time job and he hopes to expand the business. And third, working differently from the norm tends to generate fresh ideas and exciting solutions—and that is what we need more of.

This article appears in Circuit Cellar 306 (January 2016).

Interconnect Defects (ICDs) Explained

What is an Interconnect Defect (ICD)? An ICD is a condition that can interfere with the internal circuit connections in a printed circuit board (PCB). These internal connections occur where the innerlayer circuit has a drilled hole put through it. PCB processing adds additional copper into the drilled hole to connect the innerlayer circuits together and bring the circuit to the PCB board surface where connectors or components are placed to provide final function.

If there is a defect at or near this interconnect or plating and innerlayer copper, it could lead to failure of a specific circuit (or net). This defect typically causes open circuits, but could be intermittent at high temperatures. Of significant concern is that the functionality may be fine as the PCB is built, but will fail in assembly or usage, becoming a reliability risk. This latency for the defect has put ICDs on the serious defect list in the industry. Another item is that ICDs have increased in frequency over the past five to seven years, making this a higher priority issue.

The majority of ICDs fall into two categories: debris-based ICDs and copper bond failure ICDs. Debris-based ICDs are caused by material left behind by the hole drilling process. This material is supposed to be removed from the holes, but is not when ICDs are found. Some causes are drill debris residues, drill smear and particles (glass and inorganic fillers) embedded into the innerlayer copper surface. The increases in this ICD type seems to be related to the increased usage of low Dk/low Df materials that use inorganic filler types. These materials generate more drilling debris and are often more chemically resistant materials, compared to standard FR-4 epoxy materials. This combination of effects makes the drilled holes much more difficult to clean out completely.

Debris-based ICD

Debris-based ICD

Copper bond failure ICDs occur when the copper connection is physically broken. This can be due to high stress during assembly or use, or the copper bond being weak (or a combination). This failure mode is also design related, in particular, increased PCB thickness, increased hole size and wave soldering all tend to increase the risk of copper bond ICDs. It seems that there has been an increase in the rate of this ICD type, which is related to increased lead-free soldering temperatures and increased board thickness over the past 10 years. Note: This condition also occurs on HDI microvias. The causes are similar but the processing is different.

Copper bond failure ICD

Copper bond failure ICD

Reliability testing has been run on both types of ICDs. Copper bond type ICDs are a significant reliability issue. They show up as assembly failures and product with weakness may have increased tendency for field failures. Drill debris type ICDs have not been shown to be a significant reliability issue in several studies, but they are an industry specification failure, so they affect product yield and costs. Well run IST testing, using a valid coupon structure, has been a very valuable testing method for determining risk due to ICDs.

ICDs can be prevented by good PCB design and improved PCB processing methods. Debris type ICDs are a function of drilling parameters and desmearing. Many of the newer materials with fillers do not drill like standard FR-4. Instead of forming a chip during drilling, they break apart into small particles. These particles then tend to coat the drilled hole walls. One factor associated with debris ICDs is drill bit heating. Factors that result in hotter drill bits cause more debris formation and residues.
Desmearing, which is done to remove drilling residues, often needs to be more aggressive when using these material types. This has been effective at reducing or eliminating debris ICDs.

Copper bond failures are a little more complex. In PCB processing, the key factors are cleaning the innerlayer copper surface so that a strong bond can form. In addition, the electroless copper deposit needs to be in good control, having the correct thickness and grain structure, to have the required strength. Testing and experience show a good processing focus, along with appropriate reliability testing can result in consistently robust product.

Design factors also play a big role. As noted above, board thickness and hole size are key factors. These relate to the amount of stress placed upon the interconnect during thermal exposure. Eliminating soldered through-hole connectors is one of the major ways to reduce this issue, as these often contain most of the larger holes. If you need to have thick boards, look into the z-axis CTE and Tg of your material. Lower z-axis CTE values and higher Tg values will result in reduced stress.

With PCB performance requirements constantly on the rise, ICDs will remain an issue. A better understanding of ICDs will help designers reduce the impact that they have on the performance of the board. Better PCB processing practices in drilling and desmear and selecting electroless copper will improve quality. Implementing best practices will reduce opportunities for ICDs, particularly changing connector approaches. Finally, this issue is taken seriously by the PCB suppliers, many of which are working to combat the sources behind ICD failures.

Doug Trobough is the Corporate Director of Application Engineering at Isola Corp. Doug has worked introducing new material introduction and PCB processing enhancement with Isola for five years. Prior to Isola, Doug had almost 30 years of experience building a wide variety of PCB types and interconnections systems, for Tektronix and Merix Corp., in a variety of technical positions, including CTO for Merix Corp. 

This essay appears in Circuit Cellar 300 (July 2015).

Altium Launches Open Beta Program for PCB Design Tool

Altium recenlty announced an open beta program for its community-driven PCB design tool. CircuitMaker is intended to address the unique needs of the electronics maker and hobbyist community with a free software offering. Anyone interested in participating in the open beta can register now at CircuitMaker.com.open-beta-Altium

The open beta testing program enables designers to immediately download and begin using CircuitMaker while joining a collaborative electronics design community. The open beta process will also provide feedback and input to refine CircuitMaker.

CircuitMaker will be available at no cost to anyone interested in using the software, with no limits to design capability. This PCB design tool from Altium offers a polished and streamlined design tool for the maker community with features such as:

  • Comprehensive PCB design technology — Built from the foundation of existing Altium technology, all of the typical features needed for modern PCB design are built in to CircuitMaker. This includes schematic-PCB integration, interactive routing, and output generation tools.
  • Advanced community collaboration — With CircuitMaker, designers have the opportunity to collaborate in a community-driven design environment, with unlimited access to contributed design and component data. This collaboratively design process is made possible by combining an advanced, cloud-based platform and an industry-standard user experience in a native application-based design environment.
  • Streamlined interface — CircuitMaker is a native application, and provides a streamlined interface, allowing new and casual designers to create designs quickly. This removes the traditional, time-intensive learning curve usually required for new PCB design tools.

Open beta registrations for CircuitMaker begins today, and is freely available worldwide to all interested electronics designers. Those interested can register now for the open beta at the CircuitMaker website.

Source: Altium