Printed Circuit Design & Fab Circuits Assembly July 2021 cover
July 2021
white arrow with black shadow
TLB Advertisement
Accutrace Advertisement
July 2021 • VOL. 38 • NO. 7
Printed Circuit Design and Fab Circuits Assembly logo
First Person
Egad, ECAD!
Mike Buetow
money matters
Stopping the cycle.
Peter Bigelow
Good enough is good enough.
Greg Papandrew
Tech Talk
Component placement: the game of compromises.
John Burkhert, Jr.
Tips for reducing resonance and SSN.
Terry Jernberg
OCR is giving me OCD – in a good way.
Kent Balius
How AI can help IoT security.
Alun Morgan
Do test fixtures test Lean strategies?
Anita Tucker
Turning off the engineering clock.
Robert Boguski
Kneejerk reaction.
Bob Willis
July 2021 • VOL. 38 • NO. 7
Printed Circuit Design and Fab Circuits Assembly logo
Design of power-supply structure on PCBs is not trivial, but there are ways to easily check current limits between a DC-DC converter and an FPGA.
by Ralf Brüning and Marcus Buecker
Printed Circuit Design & Fab Circuits Assembly July 2021 cover
Collaborative Tracking
Three options for leveraging the secure digital ledger.
by Quentin B. Samelson
Damage Deconstruction
Determining a root cause for failure can be extremely difficult when the hardware itself is so damaged that much of the evidence has been destroyed. All hope shouldn’t be lost. Some ideas on what you can do.
by Claire Brennan, Ph.D.
Solder Materials
For spread and wetting performance, certain finishes stand out.
by Pritha Choudhury, Ph.D., Morgana Ribas, Ph.D., John Fudala and Mitch Holtzer
IN the Digital Edition
Pairing our strengths.
Updates in silicon and electronics technology.
by Binghamton University
50 Years of PCB Fabrication
with Peter Bigelow
Implementing a PCB Cleaning Process
with Chris Denney and Melissa Hough
Trends in the EMS Industry
with Mike Buetow
Developing a Testing Services Company
with Robert Boguski and Regina Lathrop
POSTMASTER: Send address changes to
Rush PCB Advertisement
DownStream Technologies Advertisement
Editor in chief
Mike Buetow, 617-327-4702,

Chelsey Drysdale, 949-295-3109,

design technical Editor
Pete Waddell

editorial office
P.O. Box 470, Canton, GA 30169

Akber Roy, Peter Bigelow, John Burkhert, Mark Finstad, Bill Hargin, Nick Koop, Greg Papandrew

Clive Ashmore, David Bernard, Robert Boguski, John D. Borneman, Joseph Fama, Susan Mucha, Chrys Shea, Jan Vardaman, Ranko Vujosevic


Art Director and production
blueprint4MARKETING, Inc.,

Frances Stewart, 678-817-1286,

Brooke Anglin, 404-316-9018,

Frances Stewart, 678-817-1286,

PRINT/electronic Reprints

For changes, additions or cancellations:
UP Media Group, Inc.
Pete Waddell

vice president, sales and marketing 
Frances Stewart

vice president, editorial and production
Mike Buetow

director of group shows
Alyson Corey,

Printed Circuit Design & Fab/Circuits Assembly is distributed without charge to qualified subscribers. For others, annual Subscription Rates in U.S. funds are: $80 (U.S. and Canada), $145 (all other countries). Single copy price is $8.50. All subscription and single copy orders or inquiries should be directed to Printed Circuit Design & Fab/Circuits Assembly, PO Box 470 Canton, GA 30169, email Photocopies and issues on Microfilm/Microfiche (16mm, 33mm or 105mm) are available from University Microfilms International, 300 N. Zeeb Rd., Ann Arbor, MI 48106, Telephone 313-761-4600.

Printed Circuit Design & Fab/Circuits Assembly is published monthly by UP Media Group Inc., PO Box 470 Canton, GA 30169. ISSN 1939-5442. GST 124513185/ Agreement #1419617.

Periodicals postage paid at Canton/Ball Ground, GA, and additional mailing offices. © 2021, UP Media Group, Inc. All rights reserved.
Reproduction of material appearing in Printed Circuit Design & Fab/Circuits Assembly is forbidden without written permission.

Postmaster: Send address changes to
Printed Circuit Design & Fab/Circuits Assembly, PO Box 470 Canton, GA 30169.

UP Media Group logo
Europlacer Advertisement
Caveat Lector
Portrait photo of a smiling Mike Buetow
Content is King

hy does Siemens want a content company?

In an era where new packages are coming online quickly, and the number of parts available is staggering – major original component manufacturers can have more than 100,000 items on their line card – human management of all this takes supernatural powers.

And that begins to explain why Siemens is paying $700 million (what?!?) for Supplyframe and its platform for component data, sourcing, and trends.

Indeed, the real value Supplyframe brings is not just access to spec sheets and parametric data, but real-time data trends. What’s available? What’s ramping in demand? And for how long? Supplyframe says it can aggregate use patterns across its 10 million-engineer-strong database to determine answers to these and related questions. It can also drill down by sector and geography to ascertain which components are ramping or stagnating in demand. There’s obvious value in that. That scale is impressive.

APCT logo


China Holds The Pricing Advantage
APCT Holds The Lead Time Advantage
By Partnering With Multiple Suppliers Outside The Region!
  • One Point of Contact
  • VMI & Kanban Programs
  • Seamless Recipe Transfer
  • Risk Mitigation
  • U.S. Bonded Warehouse for Tariff Relief
  • One Point of Contact
  • VMI & Kanban Programs
  • Seamless Recipe Transfer
  • Risk Mitigation
  • U.S. Bonded Warehouse for Tariff Relief | 512.548.7435
Printed Circuit Board Solutions

APCT Santa Clara HQ

APCT Anaheim

APCT Orange County

APCT Wallingford

APCT Global

APCT Santa Clara HQ

APCT Anaheim

APCT Orange County

APCT Wallingford

APCT Global

Around the World
PCDF People
L3Harris named Michael Ingham associate manager PCB design.

Intercept Technology founder Steve Klare has passed away.

Microcraft named Garrett Harding North American sales manager.

PCDF Briefs
CCI Canadian Circuits installed a Schmoll Modul drilling/routing system.

Denkai America plans to expand its electrodeposited copper foil operations in South Carolina with a $14 million investment that will create 10 new jobs.

Element Solutions has made a binding offer to acquire Coventya Holding in an all-cash deal of €420 million (US$509 million).

Around the World
Siemens’ Deal for Supplyframe Has Immediate ECAD Implications
MUNICH – As buyers worldwide scrambled for hard-to-find components amid rising order books, Siemens in May showed its hand: a $700 million deal to acquire Supplyframe. The acquisition, which is expected to close in the current quarter, gives the OEM a leg up in offering a comprehensive path for engineers and buyers to source and design-in parts with the benefit of real-time knowledge of use trends – and possible shortages.

But while Siemens ultimately plans to apply Supplyframe’s platform across a range of markets and domains, it first plans to tackle EDA integration, incorporating certain Supplyframe technologies into its PCB design flows. In doing so, Siemens said, it will offer its PCB designers real-time visibility into global supply chains and other functionalities, aiding everything from schematic design to factory floor manufacturing.

A.J. Incorvaia, senior vice president of the Electronic Board Systems, Siemens Digital Industries Software (DIS), and Richard Barnett, chief marketing officer for Supplyframe, spoke about the planned integration with PCD&F/CIRCUITS ASSEMBLY in June.

Great designs
require more than
good tools.
You also have to know how to use them.
Box of tools used for circuit engineering
Trades from: Rick Hartley, Susy Webb, Lee Ritchey, Dan Beeker, Eric Bogatin, Mike Creeden, Gary Ferrari, and more! text
Online courses and webinars for the printed circuit engineering community.
PCU mouse
Printed Circuit University logo
Around the World
CA People
Jim Barry
Alternative Manufacturing named Jim Barry vice president, sales and marketing. He has held top executive roles with Strataflex, Eltek USA, and other manufacturing companies over more than 30 years in the industry.
August Electronics announced Paul Crawford as chief executive.
Rob DiMatteoBob Bouchard
BTU International promoted Rob DiMatteo (top left) to general manager, and BTU promoted Bob Bouchard to director of sales – Americas. DiMatteo has close to 30 years of experience in sales management, customer support and product development and has extensive knowledge of BTU’s customer base and end markets, including SMT and high-temperature applications. Bouchard has more than 25 years of related experience, most recently leading BTU’s marketing team and previously in process engineering.
Around the World
AT&S to Open 1st SE Asia Production Plant
LEOBEN, AUSTRIA – AT&S will invest RM8.5 billion (US$2.1 billion) to open its first production plant in Southeast Asia. The new campus in Kedah, Malaysia, will produce high-end printed circuit boards and IC substrates, creating some 5,000 jobs.

Construction at the Kulim Hi-Tech Park is scheduled to begin in the second half of 2021. Commercial operations are targeted for 2024.

“After very intensive location scouting globally, Malaysia has emerged as the country in which we want to push ahead with our More than AT&S strategy,” said AT&S CEO Andreas Gerstenmayer. “AT&S brings the latest generation of high-end technologies to the country and builds up a completely new technology sector. Besides manufacturing high-tech products, a significant amount of R&D activities will be executed at this new location. Malaysia can benefit its position as a technology country and can strengthen the region as a high-tech manufacturing hub in Asia.” (CD)

Around the World
Summit Interconnect Acquires Eagle Electronics
ANAHEIM, CA – Summit Interconnect continued its acquisition run in June with the purchase of Schaumburg, IL-based printed circuit board fabricator Eagle Electronics. The acquisition provides a significant and targeted expansion into the high-performance, quick-turn commercial prototyping market and extends Summit’s operational footprint into the Midwest US, Summit said in announcing the deal.

Eagle’s management team will stay in place, Summit told PCD&F. No financial terms were disclosed.

In a press release, Shane Whiteside, president and CEO, Summit Interconnect, said, “Eagle is an impressive operation with an experienced and highly capable management team. The acquisition aligns Eagle’s extensive prototyping experience and commercial market reach with Summit’s differentiated production capabilities. We are particularly impressed with their consistent investments in advanced technology capability, resulting in an equipment set that closely resembles our other Summit factories. The new capabilities that Eagle brings will further strengthen our ability to serve our customers in both high-performance commercial and defense markets, as well as broaden our relationships with key suppliers.”

Eagle was founded in 1979 and provides advanced prototype printed circuit boards to the industrial, communications, medical, automotive and military markets. Its 50,000 sq. ft. plant in the Chicago suburbs is ISO 9001:2015, U.L. and ITAR certified.

Summit is the second-largest PCB fabricator in North America in terms of onshore revenue. (CD)

Around the World
Fralock Buys Flex Circuit Maker Lenthor
VALENCIA, CA – Fralock Holdings in late May announced the acquisition of Lenthor Engineering, a privately owned manufacturer of flex and rigid-flex printed circuits. Terms of the deal, which was financed by Arsenal Capital Partners, were not disclosed.

Lenthor provides design, fabrication and assembly services to the defense and aerospace, medical device, industrial, telecom, and semiconductor industries.

“Lenthor’s advanced capabilities in flexible circuit design and manufacturing, and its leading position in high-value market segments make it a perfect complement to Fralock’s core business,” said Marc Haugen, CEO, Fralock. “We believe that Lenthor’s expertise and strong executive team, as well as its strong strategic customer relationships, especially in our overlapping market segments, makes Lenthor an excellent addition to our expanding engineered materials solutions platform.”

Fralock’s applications are used in a variety of ways that impact our lives, including equipment used to manufacture semiconductors, medical treatment, imaging and patient monitoring devices, and defense applications, satellite and spacecraft components. The acquisition will enable Fralock to expand its market position and better serve its existing end-markets from the products created by Lenthor, the companies said in a press release.

Lenthor has more than 160 employees and is the third-largest flex circuit manufacturer in the US.

Established in 1967, Fralock Holdings is a design, engineering and manufacturing company serving the aerospace, defense, medical, life science, semiconductor and other high-reliability markets. Its companies include Fralock, Career Technologies USA, Mapson Engineering, Oasis Materials, Oasis Precision, Stratemet and Ceramic Tech. (MB)

Around the World
CA Briefs

AQS purchased a Nordson X-ray Assure x-ray component counter.

Bennett Pump purchased a Kurtz Ersa Versaflow 3/35 wave soldering oven.

Bright Machines named Restronics manufacturers’ representative in New York, New Jersey, Florida, and the Southeast US.

Microart Services, a UK EMS provider, has joined forces with engineering firm Berlin KraftWorks.

More than 50 CEOs in May urged US Commerce Secretary Gina Raimondo to take concrete steps to address challenges confronting the entire US electronics supply chain.

Around the World
Annual CIRCUITS ASSEMBLY EMS Awards Program Opens – with a Twist
Circuits Assembly's Service Awards logo

ATLANTACIRCUITS ASSEMBLY has opened free registration for its annual Service Excellence Awards (SEAs) for electronics manufacturing services (EMS) providers.

Now in its 30th year, the SEAs honor companies in contract electronics manufacturing for excelling in the critical area of customer service. This year, winners will be determined through an industry-wide voting process.

The SEAs recognize four categories of EMS providers based on revenues: under $20 million; $20 million to $100 million; $101 million to $500 million; and over $500 million.

CIRCUITS ASSEMBLY will honor winners during a virtual ceremony in February 2022.

“There are literally thousands of EMS companies in the world, making it an industry at once highly competitive and difficult to create differentiation,” said Mike Buetow, editor in chief of CIRCUITS ASSEMBLY. “The SEAs are a golden opportunity for the best-in-class assemblers to separate themselves from their competitors, using the endorsement of their own customers as the differentiator.”

For more information visit To register for free, visit

The deadline to register is Aug. 13, 2021. (CD)

Around the World
Note Acquires iPro in UK, Extends Greentech Thrust

STOCKHOLM – Note in June acquired all shares in UK-based iPro Holdings, a box-build manufacturer of electronics-based products for greentech, medtech and industrial uses.

Note will pay GBP 7 million ($9.92 million) upfront in cash for iPro, a sum that could rise based on future performance. The price corresponds to an acquisition multiple of approximately 3.5 EBIT. Haddenham, Buckinghamshire, UK-based iPro has revenue of SEK 320 million ($38.7 million), employs 100 staff, and had an operating margin in line with Note’s during the past 12 months.

Owner Martin Deas will continue as managing director.

In a press release, Note said the respective companies have similar business models based on long-term customer collaborations, high quality and strong delivery performance.

Summit Interconnect Advertisement
Market Watch
Packing it in

Trends in the U.S. electronics equipment market (shipments only)

Computers and electronics products
Storage devices
Other peripheral equipment
Nondefense communications equipment
Defense communications equipment
A/V equipment
Nondefense search and navigation equipment
Defense search and navigation equipment
Medical, measurement and control
rRevised. *Preliminary. 1Includes semiconductors. Seasonally adjusted.
Source: U.S. Department of Commerce Census Bureau, June 4, 2021
A Rising Inflation Tide Can Sink All Boats
The cycle of higher unemployment and prices must be broken.

I am not an economist, but having been around the block more than a few times over the past decades, it sure looks like financial déja vu!

My career started in the mid-1970s. At that time, the economic arena was swirling from extraordinary events that, together, created the perfect storm for hyperinflation. The aftermath of the US political crisis Watergate, staggering gas lines and shortages caused by the rolling Middle East oil embargos, and questionable Federal Reserve tactics led us to double-digit inflation. At that time, I was pricing administrator for a division of a global electronic connector manufacturer. Among my responsibilities was keeping the multi-thousand-part price book up to date. This task historically was done once every one or two years. In the environment we were in, however, I was updating prices two to three times each year!

It’s with this perspective I find myself trying to read the proverbial economic tea leaves of where we are headed in 2021 and beyond.

Board buying
Don’t Let Perfection Be the Enemy of a Perfectly Good PCB
How well does your incoming inspection team know the acceptability standards?
Does your PCB quality team inspect to pass or inspect to fail? Knowing the difference between what is rejectable in a printed circuit board and what is a nonissue is more important than ever.

Skyrocketing costs, shortages of copper and fiberglass materials, and longer delivery times mean remakes are not available as quickly as before. Rejecting PCBs for things that don’t affect the form, fit or function of the final project is simply bad business.

To be clear, I am not advocating acceptance of substandard product. IPC-A-600 standards are clear as to what is good and what is not. But thanks to lack of training or misinterpretation of industry specs, incoming PCB quality inspectors are turning away perfectly good commercial-grade boards that then must be remade.

designer’s notebook
Component Placement is a Game of Compromises
Getting all the parts and processes aimed in the same direction.
Printed circuit board technology never sleeps. At this very moment, engineering teams are working out ways to increase circuit density with finer-pitch devices. When it comes to placing these components on a PCB, the margin of error shrinks along with the pin pitch. Let’s look at how we can enable these parts on the assembly line.

The first step in mass production of a PCB assembly is preparing the board to take components. The boards may be baked in an oven prior to starting the assembly process. Although they are packed in sealed containers with a little bag of desiccant, the sponge-like dielectric materials still absorb water one molecule at a time. Prebaking releases the steam that could interfere with reflow soldering.

PCB Engineering on the Move
Get your skills in order, as the industry is ramping once more.
In this month’s column, I examine the PCB engineering job outlook and evaluate the career moves we are making. Next, I switch over to PCEA Chairman Steph Chavez, who points out important attributes our personal development should include to keep our edges sharp. Again, I am happy to provide our readers with a growing list of events coming up in 2021.
PCEA Updates
The pandemic came upon us like a supersonic jet – unseen and unheard until it passed over. It compressed the atmosphere of our lives, our industry and our jobs. As it appears to be moving on with the help of remote working, masking, social distancing and vaccination, the industry is moving to positively decompress. NPI programs are now revving up once again and causing sonic shock waves of hiring activity and job movement. Were you furloughed, laid off or had your hours cut back due to the pandemic’s effects? Boom! It’s time to clap back!
Jernberg pi
The Case of the Noisy PDN
Tips for reducing resonance and SSN.
Fast interfaces and switching speeds are becoming commonplace, and with them comes increased noise, amplifying any problems within the power delivery network. Products today are the direct result of the fast signal capabilities in current technology, making it impossible to eliminate noise. This noise can be seen in the form of simultaneous switching noise, which resonates and can combine to destroy the voltage signal and collapse the signal eye. Therefore, the only viable option is to mitigate the noise via containment.

Ground is the point from which every measurement is evaluated. Therefore, any variation will affect timing and voltage. Every signal switching on the board, whether slow or fast, contributes to noise on the power and ground planes. This “ground bounce” is commonly referred to as simultaneous switching noise (SSN) and is essentially crosstalk on the ground (FIGURE 1).

Since all digital signals share a reference point (in this case ground), too much noise on one section of the board can have disastrous effects on unrelated sections of the board. With more ground planes and copper, the effects of SSN tend to be more of a local problem – such as near a chip with poor decoupling capacitors – rather than over the entire plane.

Smart Engineering
The Phenomenal OCR
At least five operation areas can benefit from switching from manual data entry.
“Innovation is the ability to see change as an opportunity, not a threat.” – Steve Jobs
Several years ago, I embarked on an advanced engineering initiative, seeking unknown, innovative ways of processing PCB design packages for manufacturing external to the status quo, with a primary objective to drive efficiency and productivity, eliminating redundant data entry and reducing human interactions with their associated software applications. I had thrown in the towel relying on our software vendors to provide real and robust solutions. In my opinion, it was not in their interest. As their focus was selling more licenses to increase revenue, developing and marketing advanced automated solutions did not support this cause. My mantra was to take internal ownership and venture into unfamiliar territories. This path led me to OCR (optical character recognition) and, although skeptical at first, the results of our analysis were phenomenal.

Product design specifications and requirements are provided in formats such as PDF, Word, Excel, HPGL, or even as handwritten notes on scrap paper. A close associate of mine calls it “e-paper.” The variety of methodologies used to convey the same information across the PCB industry that is often ambiguous is staggering, to say the least. We print, read, interpret (hopefully correctly) and manually enter these data into our respective software application, often multiple times by multiple organizations.

material gains
The IoT is Fantastic but Flawed. We Need to Fix the Vulnerabilities – and Fast
Plus, how AI can help deal with the threats.
Forget enterprise digital transformation. For better or worse, we are digitizing the world, and it’s changing everything. The opportunities to make things better are tremendous; we can save wasted energy and natural resources, democratize access to all kinds of services, improve standards of healthcare, prevent avoidable accidents, and accelerate our transition to renewable energy. By connecting everything, and introducing AI into the mix, we can gain insights we would otherwise never detect. Moreover, we can see the effects of our own behavior and use the analysis to identify ways to improve. Earlier technologies could never have done all this for us.

But there is always an “on the other hand,” and in this case the issues relate mostly to privacy and cybersecurity. We are putting more information about ourselves than ever before into the hands of data scientists. While we can expect better shopping experiences, we are at the same time disclosing insights into ourselves, our activities, and our preferences as individuals. And if we are not giving away information directly, everything we do online (and we are almost permanently online) reinforces the accuracy of any and every inference made by the AIs that constantly watch from the cloud.

Demystifying Power Integrity
How to easily check current limits between a DC-DC converter and an FPGA.
by Ralf Brüning and Marcus Buecker
The design of power-supply structures on PCBs is not trivial. It requires careful consideration and techniques to achieve the best performance. Today’s high-pin-count devices need efficient power distribution systems permitting high-speed/high-frequency switching. The space available on PCBs is increasingly scarce. Thus, engineers fight for every square millimeter, using multiple layers for the layout of signal nets and power areas, parts of the power distribution which are then connected using dedicated power distribution network (PDN) via structures.

The narrowing of various supply voltages, coupled with increasing IC complexity and the number of voltage rails required, makes power integrity analysis inevitable for high-speed designs. This applies to AC as well as DC effects. The most compelling evidence is that modern circuits like (LP-)DDR memories operate at very low voltages (LP-DDR4 at 1.1V, for example).

Hence, typical power distribution systems today contain large numbers of vias connecting the different parts of the PDN across board layers. Often, large currents travel within these PDNs. Currents can reach dozens of amps when multiple FPGA signals are switching in parallel, while parasitic switching currents can reach even higher numbers for a very short period of time. Automatic via reinforcement functionalities within the PCB design environment often add fuel to the fire. This means automatically generated via structures may not be optimally designed against the required electrical power conditions imposed by increasing currents.

Printed Circuit University (PCU) Advertisement
Collaborative Tracking
How are Electronics Manufacturers Using Blockchain Technology?
Three options for leveraging the secure digital ledger.
by Quentin B. Samelson

In last month’s introduction to blockchain technology,1 we noted how the technology offers a way to automate and simplify multiparty processes that are time-consuming, resource-intense, and therefore costly. We often summarize this sort of process as “high-friction.” But pioneers in applying blockchain to improve multiparty processes learned early that it wasn’t enough to find a process that was slow or frustrating. There needed to be a quantifiable performance (often financial) benefit as well. This wasn’t always easy to establish. Unlike applying automation to improve internal processes, the “friction” in multiparty processes occurs outside an organization. As a result, the costs and performance issues caused by that friction may not be captured well enough inside the organization to understand its true impact.

Perhaps it’s understandable, then, that the most successful early blockchain applications were often driven by companies large and sophisticated enough to not only recognize, but quantify, the opportunities and to have enough influence with their partner companies that those partners were willing to collaborate on a solution. Indeed, a recent article in MIT Sloan Management Review2 states, “The biggest challenge to companies creating blockchain apps isn’t the technology – it’s successfully collaborating with ecosystem partners.”

Printed Circuit University (PCU) Advertisement
Fischer Technology Advertisement
Damage Deconstruction
Failure Analysis of Burned Printed Circuit Board Assemblies
When it comes to contamination analysis, things are not always as they appear. by Claire Brennan, Ph.D.

In the failure analysis of electronics assemblies, we are often asked to perform a failure analysis on hardware that has undergone a significant thermal event. Hardware might be burned, melted or covered in debris. Determining a root cause for failure can be extremely difficult when the hardware itself is so damaged that much of the evidence has been destroyed. So, what can you do? Like many things, it depends. The success of the failure analysis depends on the overall degree of damage, the amount and type of secondary damage, and the history of the part. Over the years, we have developed some tools and techniques to get the most out of these challenging failure analysis requests.

The first step in these types of investigations is to manage expectations. Most customers will understand that much of the evidence was destroyed during the thermal event failure and that root cause analysis will be very difficult. It is important to discuss what types of information can be gained, however, and what may not be possible. It is also critical to get as much information as possible about the history of the part and any details about the failure itself. This proactive discussion will help lead the investigation in the “right” direction and avoid going down a path that will not yield useful information. For example, if some of the metallic hardware is corroded, it is important to know the storage environment of the unit, not just temperature and humidity, but also the amount of time the unit was stored and its relative orientation. The product history information is useful to separate damage caused by the failure versus damage that occurred before or after the failure.

Circuits Assembly Advertisement
PCB2DAY Advertisement
The Interaction of 2 Solder Paste Alloys with 5 Surface Finishes
For spread and wetting performance, certain finishes stand out. by Pritha Choudhury, Ph.D., Morgana Ribas, Ph.D., John Fudala and Mitch Holtzer

Electronic assemblers have myriad material and process choices to make, not limited to board materials, solder masks, laminate Tg’s, components, surface finishes, assembly materials and design for manufacturing (DfM) process conditions. High-reliability alloys such as Innolot are designed to meet harsh automotive conditions and extend service life of the solder joint. Applications requiring higher operating temperatures and increased number of cycles to failure have benefited by implementing that alloy. While solder alloy selection is an important factor in determining reliability of the solder joint, considerations should be made for surface finish selection to further enhance performance. This study explores surface finish factors such as IMC formation, voiding and solder spread that contribute to reliability.

Each choice can have a significant impact on the in-service reliability and commercial success of the assembly. This multi-part article will focus on data developed from an extensive study of surface finishes and solder pastes used by many global, high-reliability assembly manufacturers. The study included two commonly used solder alloys in paste form:

SMTA International Advertisement
State-of-the-Art Technology Flashes
Updates in silicon and electronics technology.
Ed.: This is a special feature courtesy of Binghamton University.
IBM unveils world’s first 2nm chip technology. SIBM announced a breakthrough in semiconductor design and process with the development of the world’s first chip announced with 2nm nanosheet technology. The new design is projected to achieve 45% higher performance and 75% lower energy use than today’s 7nm chips. IBM said this new frontier in chip technology will accelerate advancements in AI, 5G and 6G, edge computing, autonomous systems, space exploration, and quantum computing. The technology would likely not be in high volume production until 2024. (IEEC file #12281, Semiconductor Digest, 4/27/21)
Utilizing Lean Manufacturing Principles to Cut Time and Cost in Test
Building functional test fixtures in-house mitigates several of the “seven wastes.”
The mantra of the electronics manufacturing services (EMS) industry has been faster, better, cheaper for four decades, given that outsourcing isn’t justifiable without a speed, quality or cost improvement over in-house processes. Continually delivering those benefits requires a focus on working smarter that relentlessly asks, “Where can we improve?”

Taiichi Ohno’s concept of the seven wastes (muda) in manufacturing as part of the Toyota Production System (TPS) provides a good thought process for evaluating any process. To recap, those seven wastes are:

  1. Waste of overproducing (no immediate need for product being produced)
  2. Waste of waiting (idle time between operations)
  3. Waste of transport (product moving more than necessary)
Seeing is Believing
What the Hell Just Happened?
Is round-the-clock engineering any way to live?
IDLENESS, n. A model farm where the devil experiments with seeds of new sins and promotes the growth of staple vices.
– Ambrose Bierce, The Devil’s Dictionary.
What makes a marketing expert a Marketing Expert?

What distinguishes a soft skill from a hard skill?

Is expertise conferred with an MBA at the tender age of 27? (How can somebody be considered a master of anything at 27?) Does wisdom come from meeting one’s quota nine reporting periods out of 10? Is it filling up spaces with arcane verbiage, hoping the reader is overwhelmed and won’t ask impertinent questions, like what does this all mean, and how does it benefit me?

Conversely, is acquisition of a hard skill dependent on one’s mastery of differential equations, and number theory, and polar coordinates, and game theory, and Brier scores, and C++?

Age Causes Knee Damage
Soldering excursions can lead to visual process indicators.
THIS MONTH WE look at cracks in plated through-holes around the knee of the hole. FIGURE 1 shows very small via holes that were subjected to multiple lead-free soldering steps, then underwent thermal cycling with no failures but a little cracking.

The cracks visible in the microsection were found on via holes not after the initial two reflow steps and wave-soldering test boards, but after further temperature cycling at -55o +125oC. No electrical failures were detected, just the impact of repeated stressing of the copper. It is a good demonstration of how reliable a board can be, but all that stress does have some visual impact. Care must be taken during microsection preparation to see these indicators.

SEMI Advertisement
Off The Shelf
off the shelf typography
Machines Materials Tools Systems Software
APT-1400F-SL-A flying probe test system
Takaya APT-1400F
APT-1400F-SL-A flying probe test system for PCBAs delivers larger testing area (635 x 610mm) to accommodate 5G communications and battery management system applications. SL series provides 48% larger test area; A series designation (inline configuration model) enables automatic transfer of UUT. Automated conveyor.
Loctite Ablestik ABP 8068TD high thermal die attach paste
Henkel ABP 8068TD
Loctite Ablestik ABP 8068TD high thermal die attach paste is for use in applications where no die back-side metallization is required. Is for bare silicon die integration and high-power applications. Dissipates heat in applications where bare silicon die are used. Bulk thermal conductivity of 50 W/m-K.
OvenSentinel continuous monitoring technology
ECD OvenSentinel with Profile SnapShot
OvenSentinel continuous monitoring technology now has Profile SnapShot, a one-button, on-demand oven profile confirmation that delivers a data file, rather than a profile image only. Reduces requirement for incremental profiling using instrumented assemblies. Delivers instantaneous view and generated data set of oven profile, allowing validation and documentation of oven conditions for reflow soldering. Calculations can be instantly captured and displayed. Integrates TrueProfile traceability.
Resinlab Advertisement
Topline Advertisement
PCB 4 Less advertisement
Rush PCB Marketplace Ad
Overnite Protos advertisement
Technical Abstracts
In Case You Missed It
“Impact of Thermal Cycling on Cu Press-Fit Connector Pin Interconnect Mechanical Stability”

Authors: Yeon-Jin Baek, et al.

Abstract: Compared with a BGA interconnection press-fit pin connector, interconnects are expected to have a different degradation mechanism. In this study, the impact factors affecting the reliability and degradation mechanism of press-fit connector pins were investigated. The bonding strength of inserted pins was measured before and after thermal cycling at room temperature and elevated temperature conditions. Bonding strength of the press-fit pins to the PCB copper barrel was observed to increase after thermal cycling. Development of an intermetallic compound between the copper pin and the copper barrel is observed. The microstructure of the press-fit connector pin and the barrel and localized stress and strain levels were analyzed by electron backscattered diffraction, including inverse pole figure maps, grain reference orientation deviation maps, and strain contouring maps. Along with the increase of pull strength after thermal cycling, an increase in residual stresses was observed, while strain contouring maps exhibited a decrease in localized strains at the interface between a press-fit pin and copper barrel. (Journal of Electronic Materials, June 2021)

Pulsonix Advertisement
Printed Circuit Design & Fab Circuits Assembly logo
Thanks for reading our July 2021 issue!