kinda ugly glob-top

Feb 06, 2020 8 Replies

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The parts keep wanting to crawl up to the surface and be visible. It takes multiple coating passes to really cover them. I guess I need to find an epoxy with ideal viscoscity, and find an automated way to dispense the stuff. Messy.



I was looking for a service to glob panels of this board for us, but haven't found one yet.


John Larkin Highland Technology, Inc picosecond timing precision measurement jlarkin att highlandtechnology dott com http://www.highlandtechnology.com

Smooth-On makes some nice molding products that can make your task much easier. You could make a flexible mold that holds X number of these modules and simply pour the epoxy over them. Once cured you flex the mold to release the encapsulated PCBs.

They have lots of example video links on their web site.

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(I should own stock in this company!)

I use their products often enough at my shop to appreciate the variety of products they offer.

John :-#)#

torsdag den 6. februar 2020 kl. 02.01.34 UTC+1 skrev John Larkin:

after coating let it dry hanging up side down ?

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This is why people use potting boxes - eg many of thoses those isolated DC-DC modules.

Perhaps make (or commission) a silicone mold. put in a measured amount of epoxy and then float the PCBA top-down in the mold, you might need to brush some WD40, "MR Sheen", or other wax solution on the gold bites first.

After it's set enough to hold its shape pop them out like ice cubes.

Jasen.

Increase viscosity by adding a filler. There are various sold for epoxy.

NT

+1 This is exactly what we do here. Make a polyurethane or silicone mold (yes, we use smooth-on materials), then pot with 2 part resin from Electrolube (I like the UR5547...it mixes in its own pouch). Quick, easy, no mess, beautiful results.

Someone mentioned Silicone RTV in another thread. (I know there are two types of 'curing' ingredients.. ammonia and something else. (Acetoxy)

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George H.

What does this say?

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Thin the glop first, then spray it on?

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