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Underfill

Views: 3698


fsw

#54494

Underfill | 25 April, 2008

All,

Does anyone on the forum have experience with underfill? We have a component with QFN pkg on one of the new products. It has a thermal pad in the centre. Customer wants this component to have an underfill.

Questions - 1) Does one normally require an underfill for such components 2) Is manual application of an underfill recommended for such packages 3) Brd is already built, hence part & thermal pad is soldered. Can underfill be applied at this stage.

Regards

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#54496

Underfill | 25 April, 2008

I use Namics 8437-2 for micro BGA and flip chips. Will work for QFN or MLF after soldering. Flows well under gaps as thin as 0.001". Cure in 5-10 min at 150 C. Rock solid product. Is bit expensive. Is from Japan.

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#54547

Underfill | 1 May, 2008

Does the customer understand why underfill is used? I don't think you will gain anything on this QFN.

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fsw

#54587

Underfill | 2 May, 2008

I am of the same opinion! I don't think customer has clear idea of the underfill requirement. From our talks with them, it seems they feel that since the build is RoHS compliant, they feel more comfortable having an underfill on that component to cover any solder reliability issues!

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#54589

Underfill | 2 May, 2008

show them the cost and associate it with test data showing "no value added" and they may get the point.

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#54590

Underfill | 2 May, 2008

Betcha this is coming from someone who "read" a magazine article on how underfill is so great.

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