Screaming Circuits: PCB Finishes

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BGA Woes

Quite a few of the new chips I see coming out stick to the BGA or QFN form-factor. Sometimes they'll be referred to as WSP (wafer scale package) or CSP (chip scale package), but those are still just little BGAs.... Read more

Electronics Shelf Life

Do parts and PCBs have a shelf life? Well, yes and no. I have some 7400 series logic chips in DIP form that I bought back in 1980. Every now and then, I pull one out and put it into... Read more

PCB Planarity, Not Polarity

Via-in-pad can ruin a manufacturer's whole day. Or, if properly done, can go completely unnoticed. There are a number of ways to properly put a via in a pad but the best is to have it filled and plated o... Read more

To Lead or not to Lead. That is the question

Back at the Embedded Systems Conference in September, I had a number of folks ask me about mixing leaded and lead-free components on a PCB. It's a difficult situation for some people - especially when using old and very new... Read more

Lots Of Things Can Be Fixed

I recently posted a bit of a bad OSP board with the conclusion that it was only worthy of scrap. Over on the Circuits Assembly blog, Mike commented that if the board was expensive enough, he'd rework it and make... Read more

And What Is Wrong Is...

Quick. If you haven't had your chance to answer the question, go back and read it first. Done? Okay. #1. This is an OSP (Organic Surface preservative) finished PCB. That in itself isn't a problem. However, take notice of the... Read more

What's Wrong With This Picture?

Questions for the day: What are we looking at here? (Come on, you can be more specific than that) What's wrong with it? Where are we going? When? And... will it work? Or is it just scrap? Stay tuned. Answers... Read more

DB25 - Survey Says...

I've gotten a number of answers to my question: "What's wrong with this picture?" All good responses. Via between the connector pins Soldermask covering the pads Tight zig zag on some traces Traces real close to some of the pads... Read more

DB25 With Issues

Take a look at this footprint. We're looking at the solder-side of a DB-25 connector footprint. Given all of the smt and HDI (High Density Interconnect) we see these days, this looks pretty primitive; like it could be straight out... Read more

Oxidized PCB Finish

I've written a few times about potential and actual problems with different PCB finishes. Sometimes, the results are tragic and sometimes, just annoying. I'm not sure where this one falls on the continuum between the two extremes, or maybe even... Read more