Hi Alejandro!

Well, if you use plastic squeegees, then I would say it's really necessary.
But then you need to think about the cost of metal squeegees vs. the cost of
accurate measuring equipment. The metal squeegees are expensive, but no-where
near the cost of the measuring equipent.

I've worked at companies in the past where we've had both, metal squeegees
and measuring equipment, and almost always when a measurement was taken, I
was printing paste exactly at the height I was expecting.

On the occasions that varied, usually was because of some sort of soldermask
issue with the board, such as ordering the stencil with a 6-mil thickness and
then discovering that there was a 3-mil dry-film mask on the board. Or
getting a board that has had the vias tented with a SR1000 creating little
bumps that hold the stencil up off the board...

It's not a bad thing to have height measuring equipment, it's just so darned
expensive!

If you can control the solder mask issues (always use LPI's), and use metal
squeegees, then you'll be measuring good paste height 99.9% of the time...

My 2-cents...

-Steve Gregory-

<< Hello Technetters,

 Is there any recommendation about the necessity of measuring the solder
 paste height after printing process?
 I've seen that this is a standard activity in some companies, and I want to
 push for the implementation of this practice in my company.

 Thanks,

 Alejandro Becerra
 Quality Assurance
 (915)841-8518
 [log in to unmask] >>

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