Hello James,
Here are a few things to look for.  The 8-pin cerdip package does not have much surface area for the glass seal especially if the die is large.  A lead forming step prior to board assembly could be the cause.  If you are forming the leads inward be certain that only the minor leads (the skinny portion) are being bent.  If the major leads (the wide portions) are bent simultaneously then you may very well pop the cap from the base or cause these perimeter cracks.  Another thing to look for is cracks before board assembly.  Cerdips are prone to glass cracking caused by tube to tube handling.  I have never heard of cracking due to reflow process unless you are doing vapor phase without preheat.  Some automatic lead straighteners will crack 1000 units per hour so do not let them come anywhere near your glass sealed components.  Another cause could be a lead tinning (hot solder dip) step.  Without proper preheat a supplier could cause serious damage to the glass seal.  

If you send me a sample I can probably tell you much more. (no charge!)

Regards,
Russ Winslow

Six Sigma
905 Montague Expwy
Milpitas, CA  95035 

[log in to unmask]
www.sixsigmaservices.com
Phone (408) 956-0100 x 111
Fax   (408) 956-0199


-----Original Message-----
From: Marsico, James [mailto:[log in to unmask]]
Sent: Wednesday, May 10, 2006 6:11 AM
To: [log in to unmask]
Subject: [TN] Cracked ICs


Hello Technet,

We're seeing a recurring problem of a cracked ceramic IC, assembled on a
through-hole PWB.  The component is an 8-pin DIP, T.I. P/N 5962-9452601QPA .
The crack is located below the lead frame and radiates all the way around
the device.  Has anyone experienced this before?

Please respond directly to me, as I cannot receive e-mails from Technet.

Thanks in advance,

Jim Marsico
Senior Engineer
Production Engineering
EDO Corporation
[log in to unmask] <mailto:[log in to unmask]>
631-630-5079

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