Pls send a photo of the back drilling failure (cross section) or other failure analysis

Reuven

Think green before printing this mail... Thanks

-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of ??
Sent: Thursday, July 01, 2010 7:01 AM
To: [log in to unmask]
Subject: [TN] Single PCB backdrilling

Dear Technos,

Anyone use backdrilling tech in a single pcb? We backdrilled a lot of backplanes, but none of them should survive a second reflow process and maybe a wave process.

Here is the questions:

Does the high temperature stress affect the backdrill holes reliability?  Two reflow processes and a wave process, Consider the PTHs' drilled edge are rough, maybe they will easy to be damaged by thermal stress.

Will the the rework process of the connector damage the backdrilled holes? 

Anything we can do? No HALS? More inner layer connection? Other suggestions?

Thank you so much.

B.R.
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H3C R&D DFM Engineer312 Room, Oriental Electronics Bldg., Shangdi Information 
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Tel: 8610 82774692
Fax:8610 82774214
www.H3C.com
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