Eddie

While this may appear to be a very mundane issue it is complicated. For 
instance are you using a fixture to hold the board and minimize stress 
concentrations. As you suggest, drilling holes along the cut line will help. 
Also scoring the tabs along the fracture line will also minimize 
delamination. It has been my experience that the breakaway tabs must be 
designed to be compatible with the paneling strategy and the board removal 
process.

Best regards

Lee

J. Lee Parker, Ph.D.
JLP Consultants LLC
804 779 3389


----- Original Message ----- 
From: "Eddie Rocha" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Thursday, March 27, 2008 12:36 PM
Subject: [TN] Breakaway tabs


> Is there a standard for designing breakaway tabs? Or a standard on how 
> much
> mechanical stress during the breaking of tabs should a PCB withstand?
>
> I have a customer that is using tabs .125 wide with no breakaway holes. 
> They
> experience slight delamination/fracturing after they break these tabs.
>
> thanks,
> Eddie
>
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