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How much voiding to allow on QFN's

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#60807

How much voiding to allow on QFN's | 11 January, 2010

I know IPC is working on a spec for voiding for QFN'S. However since its not released I'm curious what others have defined as the max allowable % voiding on the leads (not center ground).

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#60821

How much voiding to allow on QFN's | 12 January, 2010

What is your concern regarding voiding in QFN solder connections?

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#60838

How much voiding to allow on QFN's | 14 January, 2010

I really don't have one, however our customers do. Since they see a spec in IPC for BGA's they have either addopted the 25% from the BGA spec or come up with their own. Also many have heard that IPC is working on defining critera. I was hoping others would come back and say we dont even look at them, or that they instituted 50% or less.

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#61028

How much voiding to allow on QFN's | 3 February, 2010

Hi, check this out. Here I'm talking about the center ground, but the same goes for the terminals. 20% voids is acceptable. But only that, Not the aperture designing regarding nr. of holes from the stencil: paste > via apertures > solderding of terminals to the pads! That is zero which means => 90 % solderjoint Terminal to pad! http://www.smtnet.com/Forums/index.cfm?fuseaction=view_thread&CFApp=1&Thread_ID=13914&#Message58952

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