Posts Tagged ‘CAF’

Simple Yield Improvement. (Part 1)

Monday, December 31st, 2012

Over the past 15 years we have seen some very amazing advancements in technology. Our electronic devices have become smaller, faster and more powerful. The capabilities of these new devices have brought science fiction to life for many of us. What the common consumer does not realize is that these advancements have occurred in a more destructive Lead-Free assembly process. Lead Free assembly methods consisting of higher assembly temperatures (around 260ºC) for longer dwell times at temperature along with a smaller processing window for success. The assembly methods today are challenged to not only maintain yields but to improve them. All the while cutting costs where ever possible. The desire to cut cost is where we see the result of unintended consequences.

I have been asked repeatedly by customers for my opinion on methods to improve yields. I evaluate designs and work with designers and assemblers on solutions to help them improve yields. This includes in process and post process yields. In other words build it right the first time and make sure it lasts in the field. A common question I am asked by customers is…

What is the one thing that we can do that can  improve our yields?

The answer is very simple… (more…)

Envision HDI

Sunday, May 22nd, 2011

Envision HDI is an alternative copper deposition process that just works. Deposition or metalization is the basic foundation of a plated through hole structure. The deposition material makes a drilled hole conductive enough to allow copper to be electroplated within the drilled hole. Without metalization there would be no plated through hole. Of course there are several different chemicals available to metalize a non-conductive surface.

Electroless copper deposition was the original chemical process employed by the pcb industry to form this conductive layer. There were many downsides to this process. Chemical cost, time of operation and waste treatment to name just a few. Some of the chemicals used in the overall process are highly toxic. The process has been improved over the years.

Copper deposition was the only option for a number of years until (more…)

Why can’t I use FR4 with Lead Free Soldering.

Saturday, January 17th, 2009

You can build a printed circuit board and solder it through a lead free soldering temperatures. It is not advisable! I know some designers that use standard FR4 for lead free soldering applications. The designs are simple single and double sided boards. The companies that they work for have done the due diligence to prove out their design and manufacturing process. On moderate to complex designs they specify lead free soldering compliant laminates in place of FR4. The compliant laminates are much more expensive than standard FR4. They made the upfront investment system by doing the testing and evaluating to save money down the road. They know what they can get away with and have the test data to prove it. However, the results are specific to their designs and their assembly process. When in doubt, play it safe and specify lead free soldering compliant laminate. In order to justify the cost of the more expensive laminate you need to understand what happens to the material at high temperatures.

The main challenge faced by a laminate system is (more…)