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SMT electronics assembly manufacturing forum.


Average paste volume estimate

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#54813

Average paste volume estimate | 20 May, 2008

Does anyone have an easy way to estimate how much solder paste is applied to a smt pcb? I understand it varies on squeegee pressure, stencil thickness, and pitch of the components but I was looking for an average. I would assume that somewhere out there someone can estimate that �2 grams of paste is used on a 2� x 2� smt pcb�.

I will then use this information to determine how much lead is used on non-RoHS products due to solder paste issues and not non-compliant components.

Thank You in Advance, Dan

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#54814

Average paste volume estimate | 20 May, 2008

We had some materials management brainiac insist that every component of a product had to have an exact quantity stated on the BOM so we had to weigh every board with and without paste printed. We rented a 4 place digital scale, weighed 5 of each board type to generate some sort of decent average, the whole nine yards.

If you REALLY need this info., do what we did and then take that average weight and calculate volume from the weight per unit volume of your paste.

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#54816

Average paste volume estimate | 20 May, 2008

And every month you were over quota on paste usage weren't you!

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#54819

Average paste volume estimate | 20 May, 2008

we buy a mpm and start to clean it, and find so much paste in it my help says did they put any paste on the boards or just throw it inside the machine. Some operators waste so much paste and the engineers ask how much did we use, they should be asking how much did we waste. Just my 2 cents worth.

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#54821

Average paste volume estimate | 20 May, 2008

They knew we had waste and accepted that as a part of doing business, and allowed the total usage to float while attributing all of the variance to waste.

They HAD to have accurate per board values for the BOM, though.

I'm just thankful they didn't ask us for accurate numbers on waste per month and hold us to that as total usage. We'd have been filtering the ESD smock wash water if that were the case.

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#54843

Average paste volume estimate | 22 May, 2008

Sure, divide the amount of paste you purchased last year by the number of boards you shipped.

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