PCB Delamination in PTH hole Views: 1368

PCB Delamination in PTH hole	tm aw	10/26/09
PCB Delamination in PTH hole	Loco	10/27/09
PCB Delamination in PTH hole	davef	10/27/09
PCB Delamination in PTH hole	BLT Circuit Services Ltd	11/03/09

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Date: October 26, 2009 12:40 PM
Author: tm aw  
Subject: PCB Delamination in PTH hole

Is it possible for an old PCB (3 yrs in storage) have delamination at PTH/via hole for double-sided FR4, 1.6mm thk PCB?

If 'Yes', is it possible that such delamination can cause open circuit or intermittent failure due to intermittent contact?

> pls find attached photo from Supplier saying that the failure at pth hole was due to blistering caused by moiture evaporate rapidly resulting delamination occur on FR-4 material from an old PCB (3yrs). Pls advise if attached picture confirms such condition.

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(http://www.smtnet.com/distributed_forums/Index.cfm?CFApp=8&Message_ID=60184)

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Date: October 27, 2009 06:29 AM
Author: Loco  
Subject: PCB Delamination in PTH hole


Yes it is possible, and yes you shouldn't trust boards that have this problem.
You're best off baking PCB's this old befor reflow.

This looks like barrel cracking, a quick google gives: http://www.eco3.co.uk/e3toolkit/e3toolkit/modules/05/05_04_j_pcbbarrelcracking.html

(http://www.smtnet.com/distributed_forums/Index.cfm?CFApp=8&Message_ID=60191)

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Date: October 27, 2009 04:22 PM
Author: davef  
Subject: PCB Delamination in PTH hole


It's not the first thing we think of in looking at your picture. First off, the lack of copper in the region of the red oval makes us think of a plating defect. We don't expect that moisture out-gassing through the barrel wall to show-up on opposite sides of the barrel.

We have questions about what we see in the picture.
* What materials are in the barrel? Is that solder, void, solder?
* How much of the barrel plating is broken?

Other questions are:
* How and when did you notice this issue?
* Were the bare boards baked prior to soldering?
* What is the thickness of the barrel plating?

(http://www.smtnet.com/distributed_forums/Index.cfm?CFApp=8&Message_ID=60198)

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Date: November 03, 2009 06:35 PM
Author: BLT Circuit Services Ltd  
Subject: PCB Delamination in PTH hole


was this hasl finish looks like it has been corroded from the inside of the hole wall looking at the shape of the break in plating

(http://www.smtnet.com/distributed_forums/Index.cfm?CFApp=8&Message_ID=60289)