Printed Circuit Design & Fab Circuit Assembly Magazine April 2020
May 2020
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May 2020 • VOL. 37 • NO. 5
First Person
Factory of the future?
Mike Buetow
money matters
Risk-reward influencers.
Peter Bigelow
Is the West overexposed?
Greg Papandrew
Tech Talk
Thorough design reviews.
John Burkhert
A crisis-management tool for the ages.
Alun Morgan
Fiber-weave effect: waiting for disaster.
Bill Hargin
An hour-by-hour look at quickturn fabrication.
Akber Roy
Component wettability tests.
Bob Willis
Factory automation and Lean Six Sigma.
Filemon Sagrero
A Covid crisis? Or just poor management?
Robert Boguski
May 2020 • VOL. 37 • NO. 5
PCB Design
The benefits of developing all boards of a system concurrently on a single CAD canvas.
by Richard Warrilow
High-Speed Design
Examples of signal degradation, where it comes from, and how to minimize it.
by Lee Ritchey
Process Characterization
In a QMP, manufacturing materials and processes used to qualify and validate production hardware confirm electrical performance in hot/humid conditions. This study applied methods documented in the standard to qualify and validate acceptable levels of flux and other residues when implementing a change in cleaning material and cleaning machine.
by Mike Bixenman, Vladimir Sitko and Mark McMeen
Up Media May 2020 cover
Remember when all we had to worry about was trade wars?
by Mike Buetow
IN the Digital Edition
The latest happenings of the Printed Circuit Engineering Association.



Producing Reliable Assemblies within an EMS Environment
Covid-19 and the Electronics Industry
The EDA Market
The State of the Electronics Industry
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Caveat Lector
Mike Buetow Editor in Chief Image
What Flexibility Really Buys Us

e left off last month commenting on the effects of Covid-19 on the supply chain and offering questions – and some opinions – on what might happen next. Interestingly, the real ugliness might not have hit yet. Anticipating the traditional supply drop-off during the Chinese New Year, most companies boosted inventories ahead of time. By the time China turned the lights back on, in late February/early March, the West was starting to slow, leaving stocks in a relatively decent position.

So far, so good.

Where China will feel it most, I think, is over the next two months, as Western demand lags and China’s domestic-based suppliers pull back so as not to overstuff the supply chain. Already, we are starting to see some layoffs in Southeast Asia. If that region has to sustain another wave of Covid-19, look out. The chain could be in for a wild ride.

Count on a lot of energy spent over the next year or so looking back at the pandemic and how various business systems fared. Anticipate an abundance of white papers brimming with would-have/should-have/could-haves. Expect more than a few seers to pat themselves on the back for having predicted the disaster.

Learn about ECAD/MCAD INTEGRATION in our latest e-book and view our growing library of resources created by the PCB design experts at EMA Design Automation.
Around the World
PCDF People
Paul Cooke Headshot
AGC-Nelco Taconic named Paul Cooke technical sales manager. He has more than 20 years in PCB fabrication with Coretec, ITL, Siber Circuits, Dynamic & Proto Circuits, and most recently FTG, where he was director of field application engineering and technical sales.
Craig Hillman Headshot
Ansys promoted Craig Hillman, Ph.D., to director of product management, new and emerging technologies. He was CEO of DfR Solutions for nearly 15 years, which he sold to Ansys in 2019.
Adam Szostek, Maria Ricart Bou, Maryam El Bakkali Headshot
Elmatica named Adam Szostek country manager in Poland, Maria Ricart Bou technical manager, and Maryam El Bakkali to customer service.
Stefana Buraga Headshot
Vitesco Technologies named Stefana Buraga hardware PCB designer. She has a degree in electronics, telecommunications and IT from Gheorghe Asachi Technical University of Iași.
Around the World
Deep Impact: Could All Electronics Benefit from Vibration Tests?
PITTSBURGH, PA – Electronics of all kinds are exposed to dramatic shock and vibration events in the field, and as such factory testing should be expanded beyond cellphones and other handhelds.

That’s according to Ansys, which asserts even larger desktop and bench units such as monitors and servers can benefit from impact testing.

“The goal of these tests is to design server packaging and housings that can withstand the impacts, jostles and shakes of its environment. For instance, a server could drop, experience an earthquake or bounce around inside a shipping truck,” Ansys says.

But while such testing gets expensive quickly, the EDA company says alternate methods available today are simply dumping live product to the floor. IBM, for instance, is using software to virtually perform drop tests.

Using specialized tools, engineers can set up parametric studies and use bidirectional CAD connectivity to assess how changing the geometry affects the impact performance of various designs, Ansys says.

The effort, the company suggests, could bring new meaning to “PC crash,” and ultimately save consumers money and frustration. (MB)

Around the World
UP Media Announces Technical Sessions for PCB West
ATLANTA, GA – UP Media Group announced more than 45 technical sessions have been selected for PCB West 2020 this fall. Overall, more than 80 abstracts were submitted for the annual conference, which takes place Sept. 8-11 at the Santa Clara, CA, Convention Center.

This year’s conference features a pair of extended talks from Lee Ritchey on power delivery system design and stackup design, plus three full days of classes from Rick Hartley. The conference covers everything from RF/microwave and mixed-signal design, circuit grounding, understanding material choices, flex circuits, signal and power integrity, to fabrication and assembly processes. Talks are aimed at the spectrum of backgrounds, from novice to advanced.

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“When it comes to the technical conference, we were clearly more selective than ever this year,” said Mike Buetow, PCB West conference director and editorial director, UPMG. “Engineers and designers have limited knowledge of proper grounding, and we are emphasizing that, plus power distribution, to help overcome noise problems associated with power bus design.”
Around the World
Charles Pfeil Publishes ‘High-Speed Constraint Values’ E-Book
ATLANTA, GA – UP Media Group announced publication of a new e-book by Charles Pfeil titled High-Speed Constraint Values and PCB Layout Methods. The free download, available from UPMG, includes the Constraint Value Calculator, an Excel-based worksheet developed by Pfeil.

High-Speed Constraint Values and PCB Layout Methods encompasses lessons learned from Pfeil’s five decades in PCB design. It covers critical length, reference planes, timing, skew, crosstalk, coupling, vias, and routing. The book provides the underlying equations and specializes in practical solutions for real-life signal problems.

The Constraint Value Calculator that comes with the e-book provides rules with appropriate constraint values for high-speed designs. It includes options for edge rate, dielectric constant, and height between the layers to determine constraint values.

The Constraint Value Calculator that comes with the e-book provides rules with appropriate constraint values for high-speed designs. It includes options for edge rate, dielectric constant, and height between the layers to determine constraint values.

High-Speed Constraint Values Cover
Around the World
US EPA Eases Up on TSCA Fees
BANNOCKBURN, IL – The US EPA said it is exploring exemptions to the Toxic Substances Control Act (TSCA) Fees Rule, says IPC.

The TSCA Fees Rule is designed to collect revenues to pay for risk evaluations of toxic substances. However, the EPA now says it will consider exemptions for manufacturers that import articles containing high-priority substances or produce such substances as byproducts or impurities.

This regulatory relief has the potential to reduce long-term administrative and financial burdens for those three categories of manufacturers. If the change is approved, manufacturers who fall into these categories would no longer be required to self-identify under the TSCA Fees Rule.

In addition, the US EPA is providing a no-action assurance to these manufacturers with respect to the self-identification requirements. This means the EPA will exercise its discretion to not pursue enforcement action against such companies for violations of the self-identification reporting obligations. (CD)

Around the World
CA People
AIM Solder appointed Daniel Gil sales manager for the Tijuana and Baja regions of Mexico.
Brenda Martin
AQS named Brenda Martin director of business development. She was director of business development at Zollner for three years, and has held related roles for Sanmina, Jabil and SMTC.
Mike Hayward
ECD announced Mike Hayward as director of EMEA operations. Hayward, who previously held a similar role with ECD, has worked in the electronics industry for over 35 years and has an engineering technology national diploma from Gwent College.
Denis Barbini, Ph.D.,
Insituware appointed Denis Barbini, Ph.D., chief scientist. He has 20 years of industry experience with Vitronics-Soltec, Universal AREA Consortium and Crucial Machines, and a doctorate in chemistry, material science from SUNY Binghamton.
Indium named Alexa Blasi global logistics manager and Huaguang Wang research metallurgist.

IPC named Ray Cirimele senior instructional systems designer.

Steve Stiller, owner of Midwest Production Specialists, has passed away.

Jeff Kennedy
Zestron named Jeff Kennedy strategy and business development manager. He has more than 30 years of engineering and management experience in system integration, process development, PWB fabrication, packaging in the microelectronics industry, and over 20 years in contract electronics assembly, most recently with Celestica.
Around the World
CA Briefs
Absolute EMS installed a MIRTEC MV-6 Omni 3-D AOI and an MS-11e 3-D SPI.

AIM Solder named Masline Electronics distributor in Northern New York.

Bosch has selected MIRTEC’s 3-D AOI.

A cluster of HDD supply chain makers has been formed in Thailand with Cal-Comp Electronics & Communications and Quanta Storage also participating, allowing them to circumvent impacts of the coronavirus outbreak.

Carestream’s Non-Destructive Testing organization announced its partnership with Creative Electron for the NDT product portfolio.

Jabil installed a cloud-based manufacturing app platform to provide operators with step-by-step instructions for each assembly application.

Javad EMS installed a Hakko HU-200 robotic soldering system.

Kyocera completed its previously announced acquisition of AVX, following the completion of Kyocera’s tender offer to purchase all outstanding shares of AVX common stock that it did not already own.

Mesago Messe announced the SMTconnect trade show in Nuremberg, Germany, has been postponed to Jul. 28-30, 2020.

Around the World
IPC Releases Automotive Soldering Addendum

BANNOCKBURN, IL – IPC has released new requirements for automotive printed circuit boards to its soldering and assembly qualification standards.

IPC J-STD-001GA/IPC-A-610GA, Automotive Addendum to IPC J-STD-001G, Requirements for Soldered Electrical and Electronic Assemblies and IPC-A-610G, Acceptability of Electronic Assemblies, is attached to both standards as it looks at board reliability requirements for the automotive industry, from assembly to inspection.

Committee members representing 17 countries worked for more than 30 months on the addendum to address criteria and acceptability requirements for PCB assemblies for the automotive industry not covered in IPC-A610G and IPC J-STD-001G. The committee was guided by the principle of providing criteria to be used in addition to, and in some cases, in place of, those in the base documents to ensure the reliability of soldered electrical and electronic assemblies that must survive the automotive environment. (CD)

Around the World
Zentech Acquires CAMtek

BALTIMORE, MD – Zentech Manufacturing acquired Bloomington, IL-based EMS firm CAMtek for an undisclosed sum. Following the transaction, CAMtek will become Zentech Bloomington (IL) and joins Zentech Baltimore (MD), Zentech Fredericksburg (VA) and Zentech Dallas (TX), which Zentech acquired in January.

Christine Davis, founder of CAMtek, will continue to manage Zentech Bloomington.

CAMtek is AS9100D certified and features four SMT lines and more than 100,000 sq. ft. of manufacturing space. The company focuses on the military, industrial and commercial markets.

“CAMtek is an outstanding company with strong leadership, and we are very pleased to welcome them to Zentech,” said CEO Steve Pudles. “From certifications to engineering talent, and from capabilities to technology commitment, CAMtek very closely mirrors our core values and will be a true asset to the Zentech brand as we continue our strategic build-out and market leadership across key geographies in the US high-reliability electronics contract manufacturing industry.” (CD)

Around the World
Lacroix to Open ‘Smart Factory’ in France

BEAUPREAU-EN-MAUGES, FRANCE – Lacroix Group is part of a group investing €25 million (US$26.7 million) to establish a 16,000 sq. m. (172,000 sq. ft) smart factory here. The new plant will feature six production lines, including one exclusively dedicated to large automated production runs, and is expected to be fully operational by the end of 2021.

The EMS provider is opening the plant with help from the SPI fund, administered by Bpifrance. It said it would increase its competitiveness in traditional electronics system markets but also develop its presence in new growth markets, particularly in industrial IoT and large automated production runs.

“I am extremely pleased and grateful for Bpifrance’s support, through the SPI fund, for our 4.0 electronics factory project,” said Vincent Bedouin, CEO of Lacroix. “We have conceived this project as the standard-bearer of industrial renewal in the French electronics assembly sector. With this entirely digitized factory, integrating the most advanced technological standards, we are equipping ourselves with a powerful industrial tool, capable of meeting the challenges of an electronics market that is complex, competitive, international, and rapidly changing.”

“We are very happy to support the deployment of a 4.0 production site in Maine-et-Loire with Lacroix Group,” said Eric Lecomte, senior investment director, Bpifrance. “This investment will make it possible to meet the strong growth in activity, and to maintain our skills and know-how in complex electronic equipment with a strong technological component.” (CD)

Market Watch
Top 50 EMS Company Revenues Flat in 2019

NEVADA CITY, CA – In 2019, the top 50 global electronics manufacturers had $344 billion in revenue combined, up 0.4% year-over-year, according to Manufacturing Market Insider, a division of New Venture Research.

Overall, the APAC region accounted for around 90.2% of the Top 50 EMS revenue, the Americas 7.4% and EMEA 2.3%. In contrast, during the 1990s the Americas accounted for more than 50% of all production, with EMEA assembling an estimated 30% and APAC serving around 20% of total production.

We Can Learn from Covid-19. Will the Lessons Take Hold?
Motivated by fear, businesses are valuing creativity as never before.

Over the past 60 to 90 days, I am sure I have heard the term “the new normal” at least a thousand times. Before Covid-19 has run its terrible course, I fully expect to hear it at least a zillion more. But what exactly is “the new normal?”

Sometimes global events become a catalyst for change. Events like the Great Depression and World War II had dramatic, difficult and often devastating impacts on the world. However, those impacts were mostly temporary reactions to transient events, like the aftermath of a very bad storm. Covid-19 is different, which makes trying to visualize and comprehend events, both in the now and the future, so difficult.

Covid-19 truly levels the playing field. Everyone on earth will at some point be impacted, regardless of gender, political orientation, geography, socioeconomic status or faith. Everyone is at risk, and everyone will be impacted in similar ways. That differs from past global events that typically were the cause of regional wars (even WWII did not impact all countries), economic downturns, political eruptions, or local plagues. We really are all in this together.

Board Buying
Is It Time for a Pandemic-Resistant Supply Chain?
Or will the West continue to risk exposure?

The massive disruption caused by Covid-19 has revealed the fragility of the global supply chain. With proper leadership, however, many companies are adjusting (or will adjust) to the changes made necessary by this pandemic.

Predictably, this unprecedented disruption has prompted calls for nations to onshore their manufacturing. It’s an argument that pops up periodically. And on the surface, it does make sense. Why leave a domestic market so vulnerable to what’s going on in the rest of the world? Why not build all we need here?

But here’s some straight talk: It is simply not realistic to think we can bring all manufacturing – including printed circuit boards – back to Western shores.

Would our companies – or our local, state and federal governments – be willing and able to invest the staggering amounts of money needed in the necessary technology? Would they also be able to help supply the skilled labor force required?

What to Bring to the PCB Design Review
Design reviews can easily go off on tangents. Make sure you’re the one sharing your screen.

Every job eventually gets to tape-out day. But before that day comes, a lot of moving parts are wrangled into place. Even the simplest layout will require deliverables for assembly, including custom paste stencil and a bill of materials to associate the correct component for each location on the board. Along the way, a set of physical and electrical properties will be used to gauge line width and length, among other parameters (FIGURE 1). Getting the responsible parties to give guidance on the many assumptions made during layout is the point of the design review.

Placement spacing and orientation. Two types of assembly data are used in the factory: the kind we can see or touch and the kind that has meaning only to the machines. Robotic assembly is programmed from an x-y coordinate file. An assembly drawing provides a visual representation, including reference designators, component outlines and, important, the orientation with a pin-one mark. A hard copy of the assembly drawing is an item for the review.

If you’re lucky and well-supported by physical design (MCAD), you might also see an outline drawing for the PCB and perhaps an interface control drawing (ICD) that presents all the electrical details pertaining to any connectors to the outside world. You don’t usually expect these types of drawings until everything is said and done, and then only because the customer requested them. Every MCAD to ECAD flow has the potential for missed requirements. To close this loop, invite the physical design engineer to the review.

An update on the PCEA direction, plus highlights of the Silicon Valley chapter.
In my debut as author of this column, I provide updates on the direction and leadership of the PCEA, and Stephen Chavez shares his first “message from the chairman.” In addition, Bob McCreight, president of the Silicon Valley chapter, discusses their “lunch and learn” event held in February. Last, we share our updated list of professional development and event opportunities, although some may be affected by the Covid-19 outbreak. Stay tuned for more updates.
PCEA Updates
Over the past few months, our writer for The Digital Route, Stephen Chavez, was unanimously elected chairman by our newly formed executive board at the PCEA. Steph graciously accepted, and the PCEA is delighted to be part of a vibrant, highly skilled team of PCB industry folks now led by an experienced, young and newly minted chairman. Steph has demonstrated a zeal for helping the electronics industry and is surely capable of leading us successfully into the next decade (FIGURE 1).

Steph has mentioned his main objective in writing was to promote continued globalization of knowledge-sharing for all involved in the design, fabrication, assembly, and test of printed circuit boards. The Digital Route has been Steph’s labor of love for the electronics industry. He has put in many hours of his own time to lay the foundation, solicit interesting content, and craft this column into a must-read for people who want to engage.

Material Gains
It’s Often Maligned. But the Internet is Probably the Best Crisis-Management Tool We’ve Ever Had.
As we wait out Covid-19 at home, energy use and thermal management issues remain.
Many of us have been spending a lot more time with our computers than usual, working from home, shopping online, connecting with friends remotely, and consuming more streaming services. In the past, traditionalists have criticized such “virtual living,” but in the current situation we are fortunate to have these services that help us connect and carry on without physical contact.

On the other hand, it seems the earth is enjoying the break, particularly areas of China and the US usually suffering from traffic smog, and in Venice’s now clearer canals. The environmental effects of this unprecedented worldwide shutdown of human activity could provide interesting data to mull over as we seek solutions to our ongoing climate challenges.

It’s less clear whether there will be any significant effect on global temperatures. Our online services are a lifeline, but running the internet consumes a huge amount of energy. It’s reckoned that the six billion cumulative streams of the most popular music video in history – Despacito – have consumed as much energy as 40,000 US households in one year, generating carbon emissions equivalent to the annual output of 100,000 taxis.

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Who Should Be Concerned about the Fiber-Weave Effect?
Most boards will work just fine. But what if they don’t?
Over the past year, I’ve written a good bit about glass-weave skew (GWS) and next-generation loss requirements, using PCI Express guidelines as a means of tracking what higher frequencies do to eye patterns. This month, we’ll combine important elements of both these technology series, with just a bit of review in order to make this column one that can be read as-is.

The problem with human behavior is many of us wait for some sort of catastrophic event before we course-correct. When should we get serious about glass-weave skew, as opposed to ignoring it, while hoping it doesn’t turn around and bite us at some point in the field? (A near-worst-case scenario.)

When I was marketing signal-integrity software in the 1990s, many engineers would appear on my radar reactively, playing whack-a-mole after spinning multiple prototypes or field failures. Over time, the list of possible causes grew to include crosstalk, loss in all its forms, and eventually power integrity. I’ve noticed many of today’s hardware teams are sort of on cruise control relative to the “fiber-weave effect” as a design concern, so my objective here is to explore the concept of whether designers should worry about it proactively, given the potential impact of seemingly random field failure in production.

PCB West 2020
Connecting Design to Fab to Assembly
Conference: September 8 – 11
Exhibition: Wednesday, September 9
See you in September!
  • More than 35 sessions, plus 11 free classes!
  • All the hot topics, including grounding, power distribution, signal integrity, flex circuits, and RF circuits
  • Training for designers, fabricators and assemblers, from novice to pro
  • Rick Hartley and Lee Ritchey
  • Professional Development Certificates
  • One-day FREE Expo with 100+ leading suppliers
Who’s Exhibiting

Accurate Circuit Engineering

Aculon, Inc.

Advanced Assembly

Advanced Circuits

AGC Chemicals Americas, Inc.

AGC Nelco America Inc.

All Flex Flexible Circuits & Heaters

Altium LLC

American Standard Circuits, Inc.


Arlon EMD Specialty

Bay Area Circuits, Inc.


Bittele Electronics Inc.

Bowman XRF

Cadence Design Systems

Cicor Group

Clear Blue Engineering


Dino-Lite Scopes (Big C)

DownStream Technologies, Inc.



Dynamic Electronics Co., Ltd.

Elgris Technologies, Inc.


EMA Design Automation

EM Solutions Inc.

Firan Technology Group – FTG

Fischer Technology, Inc.

Flex lnterconnect Technologies

Flexible Circuit Technologies

Freedom CAD Services, Inc.

Fujipoly America

Goal Searchers Co., LTD Zhuhai

Green Circuits


GTS Flexible Materials Ltd.

HIE Display Limited



lmagineering, Inc.

Integrated Technology Ltd. (ITL Circuits)

IPC-2581 Consortium



JS Electronic Co. Ltd.

Kinwong Electronic Co., Ltd.

Krypton Solutions

Kyocera International, Inc.

Leader Tech, Inc.

LPKF Laser & Electronics

Medcadtron GmbH

Mentor, A Siemens Business


Minco Products, Inc.

Multek Technologies, Inc.

MV Circuit Technology Co., Ltd.

MVINIX Corporation


Oak-Mitsui Technologies LLC

Ohmega Technologies, Inc.

Oki Printed Circuits Co., Inc.

Optiprint AG

Panasonic Electronic Materials

PCB Power Inc.

PFC Flexible Circuits Limited

Polar Instruments, Inc.


Printed Circuits

Pulsonix PCB Design Software




Rogers Corporation

Royal Circuits

San Diego PCB Design

San-ei Kagaku Co., Ltd.

Sanmina Corporation

Screaming Circuits

SEP Co., Ltd.

Shenzhen Danyu Electronics Co. Ltd.

Shenzhen JDB Technology Co., Ltd.

Shin Yi PCB Co., Ltd.

Sierra Circuits, Inc.

Slingshot Assembly

Somacis Inc.

Summit Interconnect

Sunshine Global Circuits

Sunstone Circuits

SVTronics, Inc.

Taiyo America Inc.

Tempo Automation

Ticer Technologies

Ultra Librarian

Varioprint AG

Vayo Technology

Ventec International Group

Victory GiantTechnology (Huizhou) Co., Ltd.

VYCOM Global Sources Ltd.

Xiamen Bolian Tech. Co., Ltd.

Zuken USA Inc.

Conference: September 8 – 11
Exhibition: Wednesday, September 9
Multi-Board Design for Applications with Different Voltages
The benefits of developing all boards of a system concurrently on a single CAD canvas.
A multi-board system comprises two or more interconnected PCBs in a single enclosure. Typically, the boards will have very different roles. For example, if you consider e-mobility (i.e., the industry trend of switching over to electric drive trains and actuation in the automotive, aerospace and other transportation sectors), many modules are multi-board systems. One board will be a controller. Another will be for switching in and out potentially high current loads.

While they share many common design and manufacturing considerations, the PCBs will warrant special attention when it comes to their specific roles. In this respect, the controller board might be very high-density and feature BGA devices (with hundreds of balls each), flip-chip devices, wire-bonded die and embedded components (i.e., the PCB substrate contains structures with resistive and/or capacitive properties).

The controller board may also feature high-speed digital and possibly even RF signals, and ensuring signal integrity through impedance matching will be of paramount importance. As for the power board, it may need to handle hundreds of amps, so thermal management may be the biggest challenge.

Minimizing the Effects of Vias on Very High-Speed Digital Signals
Unwanted capacitance hanging off signal traces can cause unwanted resonances and excessive attenuation.
Data rates for very high-speed data links keep climbing. PCIExpress Gen 4 is 16Gb/s, and Gen 5 is 32Gb/s. Data rates on links in high-speed routers and servers are as high as 56Gb/S. RF engineers would call all these microwave frequencies, even though they are “just” digital. It should come as no surprise that elements that did not matter at lower data rates can have significant effects at much higher data rates. Vias are one of these.

It has been shown many times that the vias used to connect signal pins to traces on innerlayers of PCBs are visible. It has also been shown that the effects of these vias can be ignored at the clock frequencies used until the advent of very high-speed differential signaling. Much to the dismay of design engineers, at very high data rates these vias often are the source of unexpected signal degradation, often to the point of failure. Here we show examples of this degradation and where it comes from, along with methods for minimizing this degradation.

For the purposes of this article, “via” refers to any plated through-hole used to connect a signal trace to a component pin or a connector pin. A via has distributed inductance along its length just like any other conductor. A via also has distributed capacitance along its length, formed by the barrel of the plated hole and the surrounding planes through which it travels. When a signal travels the length of the via, the two parasitics, capacitance and inductance, form a transmission line much like any signal trace. When the signal travels only part of the length of the via, some of the capacitance is left hanging off the signal trace. This is often called a “via stub” by mistake. FIGURE 1 shows the effects of these two choices. The layer-changing via is located in the center of each trace.

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Process Characterization
Qualified Manufacturing Process Development by Applying IPC J-STD-001G Cleanliness Standard
A test vehicle and qualification test for proving out process changes. by MIKE BIXENMAN, VLADIMIR SITKO and MARK MCMEEN
IPC J-STDF-001G states, “Unless otherwise specified by the User, the Manufacturer shall [N1D2D3] qualify soldering and/or cleaning processes that result in acceptable levels of flux and other residues. Objective evidence shall [N1D2D3] be available for review.”1 ( Ed.: N1D2D3 means no requirement has been established for Class 1, and the condition is a defect in Classes 2 and 3.)

In a qualified manufacturing process (QMP), manufacturing materials and processes used to produce electronics hardware are benchmarked and validated against electrical performance in hot/humid conditions.2 Characterizing chemical residues that exist on a manufactured assembly, and assessing the impact of those residues on electrical performance, has much to do with the end-use environment in which the hardware will operate. The other important factor is the circuit density and component types. Leadless and bottom-terminated components are more susceptible to residue challenges due to low standoff gaps, tight pitch, high solder mass, and blocked outgassing channels.

Here, we assess the impact of process residues on electrical performance to qualify electronics hardware and the manufacturing process. The qualification methodology will determine the acceptability of the residue condition at the point of the manufacturing process just prior to the application of conformal coating.

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EMS 2019 in Review: Trade Wars Batter Supply Chains, Profits
The largest players in contract assembly toughed out last year. This one might be worse. by MIKE BUETOW
No matter what happened in 2019, it will be remembered as the end of a bull run. On financial charts, it will look 2001 and 2006, the last spike before the ensuing crash. As it now stands, it will take a significant surge over the rest of 2020 to make the year look respectable compared to the past several. Thanks, coronavirus.

As we roll out the Circuits Assembly Top 50 EMS Companies list, we chronicle the past calendar year, where M&A activity rose, and many manufacturers spoke of tightening their profit belts.

It seems passé now, but for most of the year the big story was the escalating trade war between the US and China. Although the accusations and antagonisms were swelling on both sides for years, the US fired the first real shot, slapping tariffs on washing machine and solar panel imports in January, followed two months later with steep taxes on steel and aluminum imports. A month later, China retaliated with tariffs of up to 25% on more than 100 US-made products, and the battle was on. When all was said and done, supply chains were being revamped, and manufacturers were scrambling to adjust pricing and maintain margins.

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tech tips
How to Build a Batch of 12-Layer PCBs in 72 Hours
An hour-by-hour look at the quickturn fabrication process.
We were presented with a challenge: Is it possible to build 10 prototype 12-layer boards in 72 hours? It wasn’t a rhetorical question; a customer really wanted just such an order. So, with time at a premium, our engineers put their heads together and created a “plan of attack” that optimized all resources. One key to success is performing a number of the steps in sequence as needed, so panels are ready when they are required. We’ll describe the procedure hour-by-hour as follows:

Hour 1: The CAM operator runs a DRC (design rule check) process and accepts or rejects the data files. If a problem exists, they contact the buyer to work out a solution; e.g., if two traces are too close, and one needs to be moved. Once the data file is accepted, the next action is to set up the innerlayers.

Hour 3: The innerlayer part of the multilayer in CAM is set up first. This will start the process before procedures like drilling or solder mask, which are not required yet. The CAM operator will scale up the innerlayers, so after etching they are all the same size. Since the innerlayers contain different dimensions of copper area, the copper and initial lamination procedure locks in stresses. Once the copper is etched off, the laminate is free to relax and stretch back, changing the size of the panel. Between the smallest change – i.e., a double-sided copper full ground plane and an innerlayer with only a few thin traces – there can be up to 18 mils of length difference between innerlayer panels over 24″ to account for. Once panelizing and processing the data for the innerlayers is finished, the CAM operator is free to work on the rest of the manufacturing package, while the innerlayers are processed.

defect of the month
Solderability Testing Using Simulation
A simple in-process test for determining component wettability.
THIS MONTH WE illustrate solderability testing using simulation. This is basically conducting simple on-the-shop-floor solderability testing to decide whether to use old components. I use paste printed onto glass slides using the paste and stencil from production. I use the same reflow profile for the board design and components in question.

These J-leaded component terminations wet successfully with the solder paste deposits on the glass plate. The paste has reflowed up, wetting the termination on the front face of the lead (Figure 1). However, look at the edge and the corners of the leads. If the solder paste has not added to the original tin plating, it calls into question the coating and component age. We have recently used this test to look at the compatibility of low-temperature solders on different terminations as well.

Factory Automation is Growing. What Will Workers Do?
How Lean Six Sigma prepares workers for tomorrow’s workplace.
People outside of manufacturing often imagine that technology’s next step is to turn factories entirely over to robots. While factory automation is growing by leaps and bounds, the reality is most automation is paving the way for workers to be far more involved in critical decision-making on the factory floor. Just as Industry 4.0 is the driving force behind smarter machines that automatically analyze and adjust processes as they inspect product, Lean Six Sigma is paving the way for a smarter workforce, capable of analyzing production trends and optimizing processes.

The benefit of Lean manufacturing philosophy is a holistic focus on eliminating issues that create bottlenecks, defects and wasted effort. It aligns well with an Industry 4.0 vision, since greater levels of automation help drive reduced variation, and eliminate excess handling and errors related to manual processing. However, while a Lean vision helps drive efficiency and improve throughput, factories with a lot of product variation, as is found in contract manufacturing, do develop inefficiencies that need to be addressed. Six Sigma provides a powerful methodology and toolbox for addressing these inefficiencies. Implemented correctly, it creates problem-solving discipline that teaches production teams how to make good choices in the problems they choose to solve, thoroughly analyze root cause, test their preferred solution and make sure the improvement is sustainable over time.

The DMAIC (define, measure, analyze, improve, control) methodology represents the heart of this discipline, teaching teams to use a measured process in their problem-solving efforts. The skillsets taught incorporate best practices in management, process engineering and quality.

A Not-So-Hot Tub of Disaster
Can a head in the sand avoid a corpse in the water?
“We’re line down.”

Sorry to hear that. (Not really, but fake empathy makes them feel better.) They got the job as the low bidder. You reap what you sow.

“We’ve been building this product for five years. That’s 22,846 units manufactured successfully and counting.”

Congratulations. You just confirmed the adage that one “oh s–t” equals one million “attaboys.”

“Not a single electrocuted hot-tubber in that time.”

How reassuring. It is of such integral services as these that our gross national product is composed.

“Now we’ve had three units fry in the space of six weeks. Customer is freaking out. Our bankers are freaking out. Management is freaking out. We are freaking out. We are dead in the water until we get to the bottom of this.”

Off The Shelf
Off The Shelf
Machines Materials Tools Systems Software
InfiniiVision 1000 X-Series oscilloscope
Easy-Use Oscilloscopes
InfiniiVision 1000 X-Series oscilloscopes now have four 2-channel models of 50MHz to 200MHz bandwidth, including a standard decode function for five serial data protocols and remote connection via local area networks and USB. Use same user interface and measurement technology as higher-performance oscilloscopes. Intuitive front panel, now available in 15 languages, features built-in help, including setup tips for complex analysis options.
Keysight Technologies
CuttingMaster 2000 and CuttingMaster 3000
Rigid/Flex Depanelers
CuttingMaster 2000 and CuttingMaster 3000 handle panels up to 350mm x 350mm or 500mm x 350mm, respectively. Come in standalone or inline configuration with integrated conveyor. High-speed and high-precision linear motor drive system with rigid granite construction. CircuitPro system software.
LPKF Laser & Electronics
MacuSpec THF 100
1-Step Cu Plating
MacuSpec THF 100 electroplating copper through-hole filling process enables improved thermal and structural designs for IC substrates. Copper structure has higher thermal conductivity than paste without thermal expansion. Reportedly faster than DC plating.
MacDermid Alpha Electronics Solutions
Off The Shelf
Off The Shelf
Machines Materials Tools Systems Software
High-Speed 3-D AOI
TR7700Q SII comes with optical system that reportedly increases stability and speed up to 25% compared to previous model. Has higher accuracy gauge R&R with stop-and-go imaging technology. Is said to be capable of 1µm optical resolution.
Test Research Inc.
MT-200 MiniTweez
0201 Thermal Tweezer
MT-200 MiniTweez is designed to rework tightly spaced micro-components such as 0201s, 0402s and 0603s. Multi-axis tip alignment capability. Tip-gap adjustment wheel matches gaps between the tips to the work.
Pace Worldwide
Net Signal Wave (NSW)
Net-Based ICT Setup
Net Signal Wave (NSW) enables flying probe testing of PCBAs for large or small and single- or double-sided PCBs. Creates net-based test program where each net in a board is characterized and a signature is learned for each. During test, production boards are compared against signature for each net. Effective for large-area, densely populated PCBAs with many nets. A large-area PCBA with 11,853 total nets, 15,534 total components, and 58,137 standard electrical test steps was tested in fewer than 10 min.
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Technical Abstracts
In Case You Missed It
3-D Printing
“Charge-Programmed Three-Dimensional Printing for Multi-Material Electronic Devices”

Authors: Ryan Hensleigh, Huachen Cui, Zhenpeng Xu, Jeffrey Massman, Desheng Yao, John Berrigan and Xiaoyu Zheng

Abstract: The authors report a 3-D printing approach that can volumetrically deposit multiple functional materials within arbitrary 3-D layouts to create electronic devices in a single step. The approach prints 3-D structures with a programmable mosaic of distinct surface charge regions, creating a platform to deposit functional materials into complex architectures based on localized electrostatic attraction. The technique allows selective volumetric depositions of single metals and diverse active material combinations, including ceramic, semiconducting, magnetic and colloidal materials, into site-specific 3-D topologies. To illustrate the capabilities of this approach, the authors fabricate devices with 3-D electronic interfaces that can be used for tactile sensing, internal wave mapping and shape self-sensing. (Nature Electronics, Apr. 6, 2020;

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