Process Solutions Consulting Inc.
Lee Levine has been a Process Engineer and Metallurgist in the semiconductor industry for 30 years. He now operates his own company Process Solutions Consulting Inc where he consults on process issues and provides SEM/EDS and metallography services.
Lee Levine has submitted responses to the following questions.
Solder Balling Splash After Reflow
In my experience solder balls are always hypoeutectic. This means the solder was overheated not underheated.
Additional heating will not ...
BGA Die and Pry Testing
I don't think that it's Kirkendall voiding. It looks like poor wetting/bad adhesion. After 500 cycles it may be strain ...
Acceptable Conductor Repair
Somepeople repair, some don't. It all depends on what your QC dept allows and thereliability requirements of the board. Certainly ...
Bromine Free PWBs
Mostencapsulent materials previously contained Bromine( halides) as a fire retardant filler. New "Green' materials contain no Bromine containingcompounds. In general ...
HASL vs. Immersion Gold
Pros: Less expensive than gold, Gold embrittles solder.
Cons: Gold is a LESS corrosive surface than any solder. If wire ...