Printed Circuit Board Assembly & PCB Design SMT Electronics Assembly Manufacturing Forum

Printed Circuit Board Assembly & PCB Design Forum

SMT electronics assembly manufacturing forum.


Double sided PCB

Sal

#4364

Double sided PCB | 26 April, 2000

Guys We currently produce a number of PCB's which are reflowed on the top side and glued on the bottom side, and the current process is to build the top side and reflow then glue and cure, is this approach correct ? or should we be curing then reflowing ? if this is so I would be more than grateful if anyone can explain the reasons why?

Sal.

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Jose Baez

#4365

Re: Double sided PCB | 26 April, 2000

Sal: You are Correct running firts the reflow side then glue side. In my Experience I've seen a reverse procesess( first glue"cure" and then reflow side) but the quality results were not good, because We realized the Glue tent to cristalise and when u apply force to review the adherence components were removed easily . So I think you are doing the job properlly. JBaez.

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#4366

Re: Double sided PCB | 26 April, 2000

Hi Sal, the way you do it has IMO some advantages: - no sophisticated support for the topside print - no extra thermal stress for the the bottomside bonding material - less possibilities to lose bottomside components by handling

One disadvantage might be the printing of the glue, you need a support fixture. If it works for you, why change it ?

M2C

Wolfgang

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