Quest for Reliability: Reliability by the Book

Standards have been around in the industry as long as the industry itself. But if they are followed, does that mean that you’ll have improved reliability? The answer is a famous one in certain circles; it depends on a few things, such as the product’s intended use and warranty. If you are building something that must work only as it leaves the facility and is considered a Class I product, then reliability isn’t something you need to worry about. But having been in electronics for just shy of 20 years, I can say that the next time we work on a Class I failure analysis project, it will pretty much be the first. Class I electronics serve a different purpose in life, and if they fail, it’s normally not a big deal; instead, it’s mainly a minor inconvenience. In this month’s column, I’ll speak to specifications for Class I, II, and III products per IPC definitions as well as the IPC standards process.

Class I, II, and III

The low-cost materials and disposable nature of Class I products basically preclude them from ever being labeled as high-reliability. Within IPC guidelines for Class I, the assembly guidelines are very different than Class II or Class III. This isn’t necessarily a knock on Class I products by any means. IPC’s definition for Class I is “includes products suitable for applications where the major requirement is the function of the completed assembly.” There’s not a single word about reliability or critical nature of their intended use.

Class II is defined as dedicated service electronic products, which “includes products where continued performance and extended life is required, and for which uninterrupted service is desired but not critical. Typically, the end-use environment would not cause failures.” Class II products would be found in a lot of automotive electronics, not related to safety, as well as harsh environment electronics that may not necessarily be life-critical but are expected to operate for 20+ years.

Class III is defined as “products where continued high performance or performance-on-demand is critical, equipment downtime cannot be tolerated, the end-use environment may be uncommonly harsh, and the equipment must function when required, such as life support or other critical systems.” These electronics are most commonly found in industries like healthcare and aerospace. When your life, or the life of others, is on the line, Class I simply won’t do.

The standards for assembling Class II and III are well known with IPC J-STD-001 being the cornerstone of the J-STD series of standards. J-STD-001 is titled “Requirements for Soldered Electrical and Electronic Assemblies,” which covers a lot of ground. The Technical Activities Executive Committee (TAEC) says, among other things, that standards should focus on the end-use environment, not tell you how to make something. That last part is very important to remember because standards aren’t the full recipe necessary to build electronics; they should be considered a guideline to reference when there is uncertainty on how to do some part of the process. The order of precedent on any drawing should be as agreed between the user and the supplier and standards like J-STD. This helps to drive home the point that IPC standards are not necessarily the final word on how to build a PCBA, but should be used as a companion to the demands of the customers.

To read this entire column, which appeared in the September 2019 SMT007 Magazine, click here.

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2019

Quest for Reliability: Reliability by the Book

11-04-2019

Having been in electronics for just shy of 20 years, I can say that the next time we work on a Class I failure analysis project, it will pretty much be the first. Class I electronics serve a different purpose in life, and if they fail, it’s normally not a big deal; instead, it’s mainly a minor inconvenience. In this month’s column, I’ll speak to specifications for Class I, II, and III products per IPC definitions as well as the IPC standards process.

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Quest for Reliability: SMTAI 2019 Thoughts

10-16-2019

Before I headed to Rosemont, I was a little skeptical if it would be worth it for me, considering the lack of task groups that had become my SMTAI/IPC APEX EXPO focus. But after three days of sessions (and a somewhat impressive third-place showing at the SMTA trivia night), I was reminded of why I went to SMTAI in the first place: to learn about the newest technology and how to address age-old problems that are ever-evolving in this era of miniaturization.

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Sealing Your Fate

08-16-2019

Coating does not always prevent failures; it is just as important to look at your cleanliness levels just as you would with an assembly that is not bound for coating. If you have a dirty assembly, you might be buying a little time, but ultimately, you've sealed your own fate.

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Quest for Reliability: The F Word

07-19-2019

The word "failure" is as nasty as it gets in our world. It goes against everything we thought we knew. All contract manufacturing facilities strive to build a reliable product, or at least they all should. The problem is too many companies hope they are building reliable products without doing the work required to ensure they are.

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Quest for Reliability: These Darn Kids/Back in My Day

04-24-2019

This month’s topic is focused on youth, both in terms of humans and technologies. I think these two topics go together since they rely on each other to a large degree. The latter has more than likely shaped or even invented by the former.

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How Smart Is Your Factory?

04-03-2019

When you plan a production facility with the mindset that connectivity and optimization will be key aspects of your operation, it will pay dividends in the form of lower production cost, better traceability, and higher reliability.

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The Cost of Quality and the Higher Cost of Failure

03-13-2019

If you are shopping a new product around to multiple contract manufacturers (CMs), and if all other things in two separate CMs are equal including price and delivery times but one offers a more comprehensive ongoing quality monitoring system, why wouldn't you go with that one? You usually pay some type of premium for the CM that has an overall quality monitoring system that goes beyond just ICT or bench level testing. Definitely, most CMs will give you some sort of assurance that the product is working as it leaves the facility, but if one has a mindset that more than basic testing is required to show reliability, you will more than likely have fewer field failures.

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The Effect of Thermal Profiles on Cleanliness and Electrical Performance

02-21-2019

The process of thermal profiling is one of the most important considerations when setting assembly parameters in reflow soldering. Knowing how to effectively profile includes choosing the proper equipment, understanding the results and being able to adjust as necessary.

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How to Achieve the Apex of Reliability

01-02-2019

Knowing the effect of residual ionic content is among the most important data points when looking at reliability because it is directly related to electrical leakage and electrochemical migration-related issues in a normal field service environment. This column discusses the test methods mostly related to cleanliness and different ways to determine if the process is clean enough for the intended end-use environment.

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2018

Does Medical Device Reliability Worry You Sick?

12-06-2018

When you are manufacturing high-reliability assemblies related to medical industry, it is critical to take a very close look at the assembly process and all other processes that can influence the end-use reliability—even seemingly unrelated processes, such as post-installation cleaning—as it really could be a matter of life or death.

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Are You Connected to Reliability?

10-30-2018

The need for communication between every operator on the manufacturing floor can be a critical difference between a reliable piece of hardware and one that presents some level of unexpected performance. This column highlights a few things happening in the shop floor, such as as touch-up soldering and third shift issue, not commonly communicated, which can cause performance issues.

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Are Megatrends Putting Your Product at Megarisk?

10-03-2018

It took 38 years for radio to get 50 million users, television made it in 13 years, Internet in four, iPod in three, and Facebook in only two years. What these numbers mean to our industry is the need to create electronics at blazing speeds that we haven’t seen before. But how will it affect reliability? Read on.

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Cleaning a No-clean Flux: The Worst Decision You’ve Ever Made?

09-04-2018

There are a few reasons to choose to clean a no-clean flux, such as when the PCB assembly requires conformal coating, or when probes are required for testing. Other than that, there seems to be no need to clean a no-clean flux. This column tells you more.

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Contamination: The Enemy of Electronics

07-18-2018

Welcome to the first installation of “Quest for Reliability.” The goal behind this column is to use my experience at an independent laboratory for over 18 years to help readers understand PCBA reliability issues, and more importantly, prevent suspect conditions in the first place. The laboratory I work in has served every sector of the electronics industry, from oil and gas equipment designed to function miles below the surface of the earth, to aerospace companies and everywhere in between.

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