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

Printed Circuit Board Assembly & PCB Design Forum

SMT electronics assembly manufacturing forum.


PCB green mask darker

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#59851

PCB green mask darker | 14 September, 2009

The PCB green mask will become darker after few times IR reflow? What is the reason? Any acceptance spec refer to green mask requirement?

Any method to measure the color level for PCB green mask? By naked eye or machine?

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NCJ

#59860

PCB green mask darker | 15 September, 2009

Darkness of the green mask changes with increased temperature prior to settling down. However, you can specify the ingredients used in the green mask prior to making the PCB's to your liking. Usually, once the green is set it is hard to change its color unless too much heat is used during SMT process (i.e. >350 deg).

Kenneth

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