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February 2010

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Subject:
From:
Werner Engelmaier <[log in to unmask]>
Reply To:
TechNet E-Mail Forum <[log in to unmask]>, Werner Engelmaier <[log in to unmask]>
Date:
Tue, 2 Feb 2010 19:59:46 -0500
Content-Type:
text/plain
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text/plain (62 lines)
 Hi Bob,

 Machining part of a PCB that way, makes it asymmetrical. Depending on subsequent processes, and the size of this milling of curse, you may get warping at soldering temperatures. Also, you have two different set of properties, the laminate layers and the perpreg layers.
Werner


 

 

-----Original Message-----
From: bob wettermann <[log in to unmask]>
To: [log in to unmask]
Sent: Tue, Feb 2, 2010 7:04 pm
Subject: [TN] FR-4 Mechanical Properties


Technetters:

We are working on a project where we have to mill down 0.005" on each side of a 
populated FR-4 board which is 0.062" in thickness making the nominal thickness 
0.052" +/- 0.002".

The question for you mech-e's out there is :

"How will the mechanical properties of the board change with 0.010" being shved 
off of the thickness?" 

<The thickness is reduced by this amount near a mounting hole>

Thanks

Bob Wettermann
BEST Inc


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