There are many labs that offer X-ray or CT scans, along with microsectioning, etc. For a one-time or for occasional requirements they are great.



-----Original Message-----

From: TechNet [mailto:[log in to unmask]] On Behalf Of Graham Collins

Sent: Thursday, August 30, 2018 1:26 PM

To: [log in to unmask]

Subject: [TN] qualifying a heatsink attach process



Hi technet!



We've got a customer working with high power transistors, they want to 

use solder pre-forms to solder a heatsink on top of a row of 

transistors.  So the stackup will be PCB - transistor - preform - 

heatsink, where the heatsink will span a row of 5 transistors.



The question is how do we establish that this is working OK and isn't 

full of voids?  This is at the "ok, we think this will work but we need 

to qualify the attachment method" stage.  I've come up with a couple of 

options:



1) tear / grind it off and look for anomalies - not very sure to find 

issues.

2) x-ray it - we don't have a 3-d x-ray so I'm not confident in our 

abilities to find voiding.  We do have a nice static x-ray though and 

will try it to see how well it can see.

3) Sonoscan it to look for voids?  Would have to be outsourced.



Am I missing any obvious options?



-- 

Graham Collins

Senior Process Engineer

Sunsel Systems

(902) 444-7867