I'm not sure what I see on the picture. What I can say is this: any
heatproducing and heavy component ought to be mounted in such a way,
that the electrical connections (solder joints) be mechanically free
from stress. Philips, many years ago, mounted the line transformers
directly on the board (to save money), the transformer hanging in its
solder pins. All know what happened: solder creep and electrical opens.
I had two such TVs. Every two or three years, I had to open the box and
resolder the transformer pins, and then the TV worked again. Those who
didn't know the trick had to buy fresh TVs. Just one of many examples.
So:  relaxed and free solder terminals! 

Inge

-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Bremer, Gary
Sent: den 1 februari 2007 17:02
To: [log in to unmask]
Subject: [TN] Mechanical Stress on solder joints

Gentlemen,

 

I have a device that failed in the field, the part is a DC/DC converter
that is first soldered to the circuit board then a massive heatsink is
screwed to the converter pulling the device upward because of an air gap
not covered by a thermal conductive pad. Could this be the cause of
damage to the component pins as shown in the attached photo? The solder
used is Sn63 on the circuit board side and the mass of the board solder
joint appears to be twice that of the component.

 

Gary Bremer
Senior Manufacturing Engineer, CIT
  
Curtiss-Wright Controls Inc. 
Embedded Computing -Subsystem

28965 Avenue Penn
Santa Clarita, CA 91355-4185
Main: 661.257.4430 extension 2170
Fax: 661.257.4782


e-mail: [log in to unmask]
Web: www.cwcembedded.com 

NOTICE: This e-mail communication is private and confidential and is
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