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solder paste volume model

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#59936

solder paste volume model | 22 September, 2009

Does anyone know how to calculate solder paste volume required to run a PCBA on an SMT line? I'm looking for a solder paste volume model which include paste waste.

Roland

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#59937

solder paste volume model | 22 September, 2009

To how many decimal places?

Do you want to have a factor for different screen printer operators?

There is no such formula and I doubt there ever will be one with any real accuracy.

The stencil house might be able to tell you the total area of the aperatures. You can then mulitply by the thickness. But you don't get 100% release from everyone.

Do you use tubes or jars? In either case look at the "empty" ones. There is a certain amount of randomness to how much is in each one. And I"m sure it would vary from operator to operator.

Although I suspect larger volume places might be able to do what you want with more accuracy.

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#59958

solder paste volume model | 23 September, 2009

The US EPA has a Toxics Release Inventory (TRI) program. They may have some information on paste wastage estimation for leaded pastes.

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#59986

solder paste volume model | 25 September, 2009

empf issued an excellent study of calculated solder volume in the 90's. It used lotus 123 but is easily used in excel. I have used it for over 10 years. The only thing wrong is with leadless components. the amount of paste required generally is insufficient to keep the part on the board and you need to really study the effects to come up with your own calculations.

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