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

Printed Circuit Board Assembly & PCB Design Forum

SMT electronics assembly manufacturing forum.


Conformal Coat

Views: 1045

#75778

Conformal Coat | 26 May, 2016

Not exactly SMT but something I recently did that might save you lots of time and money: Complex high $ assy that has 25+ conformal coat keep out areas - most different shapes. All locations are dimensioned on customers' print. We tried a one piece masking fixture but it just didn't work well due to the complexity. Too leaky, too much maintenance so masking tape is only option as we don't have a fancy programmable conformal coat machine. So, I designed frames and had them cut by stencil house. Frames sit on assy, aligned by tooling holes; they outline all specific masking tape locations. Next (here's the biggest time saver), I cut all the masking tape shapes on our programmable laser wire stripper. It has a 4"x 4" window and I was able to cut all the shapes in a half day - probably 1,000 or more pieces. It would have taken 2 or 3 operators all week. Bam!!! Easy money. Hope this gives you an idea or two.

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#75779

Conformal Coat | 26 May, 2016

Is the frame placed on assembly as a guide to install the masking tape?

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#75780

Conformal Coat | 26 May, 2016

Yes - the frame is built to nominal per print then the tape pieces are placed into areas in the frame as required. I had the stencil house cut #'s into the frames designating each different size. When I cut the tape pieces, I put them on a large, smooth piece of G10 or FR4 then numbered each shape as they came off the laser wire stripper.

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#75781

Conformal Coat | 26 May, 2016

Good work! We have a product we've been using a table top latex masking robot we built in house to mask keep out areas. If we could apply what your doing we can eliminate the buffer of dry time on the masking.

Any information you can provide on the programmable laser wire stripper?

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#75797

Conformal Coat | 31 May, 2016

It's a Spectrum Technologies Sienna 300 Series. The main down fall is that you can only program x and y (as far as I know). By that I mean you can't do circles or diagonals. Only squares and rectangles or shapes with only vertical and horizontal sides. If I was buying a machine just for cutting materials such as tape, I'd research a low power laser that can be programmed to do any shape using dxf/step files or something similar.

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Hioki Flying Probe Tester