Whose Fault is That Bad Board?


Reading time ( words)

Not long ago, I answered Editor Andy Shaughnessy’s “Whose Fault is That Bad Board?” survey. When I answered the first question (“If a board fails in the field, whose fault is it, typically?”), I was disappointed that he used radio buttons instead of check boxes. I did not want to blame only the designer for every bad board in the world. Did Andy want me to name the ones who are most often blamed?

Who are these designers? PCB designers are like magicians; they can materialize an idea from a piece of paper, and many of them are also the creators of the product. And designers create many jobs. Their projects may have gaps, but I would not blame designers for all the bad boards. They are the first to be blamed because they take the first step in the product’s life cycle. They can make mistakes too, but sometimes their fault is having too much confidence in the people who follow up on their work.

I know an American entrepreneur who went to Poland to open a PCB design bureau. He found painters and architects for hire, but not many engineers; he was very pleased to find many electronic engineers here in Romania. But are all engineers qualified to be great PCB designers?

Years ago, I held a position in an EMS company where projects were analysed before sending them to be produced on the assembly lines. We found that even some of the best and most innovative circuits could not be manufactured. Why? Because the PCB designer, an electronic engineer, was not acquainted with the fabrication process. He had no idea about technological requirements necessary for electronic production.

Here is a funny story: I know of one designer who learned, finally, the importance of the thermal relief pad for heat restriction during reflow for a good soldering. His response? “Oh, was that what they were for? And to think I worked so much to remove them!”

The CAD program itself had introduced thermal bridges where the pads were linked to large copper areas, but the designer’s eye did not like the way they looked. This was a happy case because the designer had presented the project before sending the order for fabrication. But other times, matters were much more serious. When a board came in for assembly, it was necessary to manually heat the pad and the component with two soldering irons. Some designers understood this aspect (especially after they were walked through the factory to see the whole technological process), while others even got angry, yelling, “I will send the project to China and they will do it!” Yes, they will, but they will fabricate exactly what was sent, including the design errors. This was the case once when a designer forgot to send an Excellon file; the printed circuit board was manufactured without the holes for the 40-pin DIL package of a microcontroller.

Some designers will gladly fit the schematic on the entire sheet. One designer learned that, with the right modifications, the area of the printed circuit board could be reduced, and thus the cost of the board could be reduced. He replied, “Oh, it is for the Army, and they have enough money not to worry for the size of the board!”

To read this entire article, which appeared in the August 2017 issue of The PCB Design Magazine, click here.

Share


Suggested Items

Excerpt: The Printed Circuit Designer’s Guide to…Flex and Rigid-Flex Fundamentals

06/25/2018 | Dave Lackey and Anaya Vardya, American Standard Circuits
The design process is arguably the most important part of the flex circuit procurement process. The decisions made in the design process will have a lasting impact, for better or worse, throughout the manufacturing cycle. In advance of providing important details about the actual construction of the flex circuit, it is of value to provide some sort of understanding of the expected use environment for the finished product.

Mark Thompson: What Designers Need to Know about Fab

06/08/2018 | Dan Beaulieu, D.B. Management Group
Mark Thompson wants to help PCB designers. He’s seen it all in CAM support at Prototron Circuits: the incomplete or inaccurate data packages, boards that are unnecessarily complex or over-constrained, and so much more. Mark just returned to writing his popular Design007 Magazine column, The Bare (Board) Truth, which addresses questions such as, “What happens to your design at CAM?” I asked Mark to explain why it’s so important for designers to communicate with their fabricators, and why they need to get out of the office and visit a board shop every now and then.

Experts Discussion: What Does 5G Mean to Materials and EDA Tools?

06/06/2018 | Andy Shaughnessy, Design007 Magazine
Whether we’re ready for it or not, 5G technology is coming. We decided to speak with John Hendricks, market segment manager for wireless infrastructure at Rogers Corporation, and Ben Jordan, director of product and persona marketing for Altium, about the challenges related to 5G and what this means for PCB designers and fabricators.



Copyright © 2018 I-Connect007. All rights reserved.