Prashant,

TechNet strips attachments.

A rule of thumb is that to keep parts from falling off:

R = C/P (g/in²) must be ≤ 30

Where
    C = Component weight in grams
    P = total pad area in square inches

Ben

-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of prashant chopra
Sent: Friday, June 06, 2008 7:52 AM
To: [log in to unmask]
Subject: [TN] Double side reflow query

Hi,

We are having a PWB wherein, we have a potentiometer and 3 PLCC package on the bottom side of the PWB.

I need help to know if there would be issue of these components falling off during the second reflow process (when top side is being reflowed)?

We not have options to move these on the top side as there are already other PLCC and BGA packages eating up the PWB land area.

Let me know your comments and also on how can we prevent these from falling off during the second reflow process?

I am attaching the data sheet for both these parts above.

Thanks, in advance to all of you for your help and precious time.

Rgds
Prashant



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