Quality programs should ensure quality, not hamstring ingenuity.
From time to time, new terms take hold that sound critically important, become heavily, if not overly, used in business conversation, and often are both misleading and oxymoronic. Such is the case with the now frequently used “single point of failure.”
I do not think it’s possible to go through a facility or quality audit by a large customer where they are not searching for – and certainly identifying – what, in their opinion, is an unacceptable single point of failure. In my experience, the single point the auditor or customer identifies is usually neither more nor less critical than any other aspect of the process, is usually not a single point, and is usually not more than a process – or processes – the person who cites it does not understand.
Over the past couple months, I took my now 14-year-old on his first electronics manufacturing factory tours. He had visited a vocational school with his 8th grade class, but I think it really opened his eyes to what real-life manufacturing looks like. He’s not considering vocational school, but I think it’s important that he – and all kids his age – understand what really goes on in (well-run) factories.
As background, “14” knows what a circuit board is, but has no knowledge of how they are made or assembled. At IMI PCB and Lightspeed Manufacturing, both located in Haverhill, MA, he was able to see the basic operations up close, and listened to explanations of how boards are transformed from digital 0s and 1s and schematics to large green (or other colored) panels and arrays, and then screened with solder paste and assembled, and (sometimes) reworked. Both plants are low-volume, high-mix operations, which altered his impression somewhat, for as a kid with multiple handhelds of his own, he naturally expected to see machines pumping out cellphone boards every three seconds.
Before he entered, I asked what he was expecting to see inside. “Mainly machines,” he said, “because since the Industrial Revolution and the invention of mass production, we are in an age where machines are huge parts of our lives. I think the machines are doing the work, and people are just here to help run them.” He was in for some surprises.
Answers to problems abound, but the questions are elusive.
High-tech companies pride themselves on their ability to deliver solutions. Firms feel useful – and justified – by doing so, thereby serving humanity. They want you to know that. The effort, or the splashy publicity emanating therefrom, ennobles them, so they think. This satisfies a certain insecure technocentric mindset, needing frequent validation. Touting solutions drives tech companies’ marketing; it trumpets, for all to hear, their reason for being. Quite an impressive spectrum, those solutions. Just sample the advertising. The magic word isn’t hard to find; in fact, it can be overwhelming in its ubiquity, in multiple languages: “Offering cost-effective solutions to the EMS industry since 1984.” “Your solution partner.” “Complete inspection solution.” “Produktloesungen.” “Innovative solutions at your fingertips.” “Soluciones Integradas.” “Creating solutions.” “Cleanroom and containment solutions.” “X-ray inspection solutions.” “Optimale systemloesungen.” “Advanced switching solutions.” “Bespoke solutions.” “Providing today’s solutions for tomorrow’s products.” “Custom NDT solutions.” “Your partner in embedded solution.” “Reliable climate solutions.” “Network connectivity solutions.” “Integrated boundary scan test solution.” “The solution to America’s problems is a big, beautiful wall.” “Customized solutions.” “Integrated test solutions.” That last one’s catchy. Bottle it.
With RoHS exemptions set to expire, can SAC 305 hang on?
It is not the strongest of the species that survive, nor the most intelligent, but the one most responsive to change.
– Leon Megginson
The final steps of RoHS will be phased in over the next 24 months. Once implemented, lead will be virtually eliminated from solder in the electronics assembly supply chain. With the last exemptions applying predominantly to high-reliability applications, materials in use are being scrutinized to determine if they can perform to the mission requirements of high-reliability PCBs.
Concurrent to this material concern is the unrelenting trend in microelectronics: more functionality and performance in smaller spaces. As circuitry becomes denser and more power is inserted into smaller spaces, an inevitable byproduct is heat. These two realities, high-reliability requirements and increased power density, are exposing deficiencies in the de facto lead-free solder alloy, SAC 305. SAC 305 has performed adequately to this point. The processing temperatures are acceptable. It has proved sufficiently durable and is largely compatible with other common materials, albeit at considerably higher cost than the SnPb it replaced. Typically, if an alloy other than SAC is in use, it’s for cost containment rather than solder joint reliability characteristics. But the needs of the industry are evolving based on the aforementioned changes in regulation and reliability requirements. As a result, SAC 305 may fall out of favor, as it has a variety of undesirable inherent characteristics.
Warping during reflow can leave solder balls distorted.
In cases where pad size, solder paste volume and solder spheres on a BGA are consistent in size, the solder joint size variation shown in FIGURE 1 is typically soldering-related. Modern x-ray systems can measure the joint sizes automatically and output a spreadsheet with the data. It is not uncommon to take these measurements on pre-production prototype builds, when product is working. This provides a permanent record of the ball variation on a satisfactory product. If problems are experienced in volume production, the results can be easily compared.
Supply chain separation has made engineering a more expensive proposition.
Based on my sailing experience, I can say with certainty a chain, such as the one that anchors your boat to a secure mooring, is only as strong as its weakest link. In the intangible world of business, however, it can be difficult to see differences between “weaknesses” versus “just another way of looking at things.”
Such was the case recently during a meeting with a large customer – the type of very large customer where they have almost as many global facilities as they do egocentric engineering personalities – when an alleged strength revealed itself to be instead the weakest link in a very long chain. Around a large table sat engineering, manufacturing, and quality gurus revealing their latest, greatest project.
Discussion focused on the “elegant” simplicity, the utilization of the “best available new technology” and of course the “time critical” requirement that all suppliers had to perform to. This was quite the humdinger of a program I am sure was going to make – or break – more than a few careers of those present.