This is interesting. I used to be, once upon a time, a process engineer in the semiconductor industry, and I’ve been playing around with a niche site on that theme. While doing so, I Googled “How to Prevent Purple Plague” because I wanted to remind myself about this Gold-Aluminium intermetallic problem. Google returned “No results found”, an amazing occurrence if you think about it – something the god-like Google has no answer to! So, I thought I’d post here ab out how to prevent purple plague just to see what happens when Google finds it. Will I be able to rank number one for How to Prevent Purple Plague? On a site that has nothing to do with semiconductor assembly?
[phpzon]Process Engineering, 3, Books[/phpzon]
Anyway, in case you really are looking for an answer to the question of how to prevent purple plague – keep your bonding temperature down. Once you’ve got it – you’ll experience ball-shear problems and if you have the facility to do a powered IC test, you’ll find conductivity problems resulting in overheating – ain’t nothing you can do. Scrap the batch, tweak the process and start again. Make sure you use SPC at the start of the batch to check for ball shear problems resulting from lower bond temperatures. And good luck.
UPDATE!! Well, only, what, 3 weeks later the answer is yes! I have indeed succeeded in coming first in the Google SERPs for a completely useless keyword! Ok, maybe not completely useless – anyone got any idea what to do now?
