kinda ugly glob-top

J

John Larkin

Guest
https://www.dropbox.com/s/y84av0633wvq104/T577_Glob_1.JPG?raw=1

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
 
On 2020/02/05 5:01 p.m., John Larkin wrote:
https://www.dropbox.com/s/y84av0633wvq104/T577_Glob_1.JPG?raw=1

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.
Click to expand...

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.

https://www.smooth-on.com/ (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:
https://www.dropbox.com/s/y84av0633wvq104/T577_Glob_1.JPG?raw=1

The parts keep wanting to crawl up to the surface and be visible. It
takes multiple coating passes to really cover them.
Click to expand...

after coating let it dry hanging up side down ?

I guess I need to
find an epoxy with ideal viscoscity, and find an automated way to
dispense the stuff. Messy.
Click to expand...

https://www.robotdigg.com/product/1433/Benchtop-3-axis-dispensing-machine-with-983-Glue-Dispenser
 
On 2020-02-06, John Larkin <jlarkin@highland_atwork_technology.com> wrote:
https://www.dropbox.com/s/y84av0633wvq104/T577_Glob_1.JPG?raw=1

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.
Click to expand...

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.
 
On Thursday, 6 February 2020 01:01:34 UTC, John Larkin wrote:
https://www.dropbox.com/s/y84av0633wvq104/T577_Glob_1.JPG?raw=1

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.
Click to expand...

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


NT
 
On Wednesday, February 5, 2020 at 6:10:16 PM UTC-7, John Robertson wrote:
On 2020/02/05 5:01 p.m., John Larkin wrote:

https://www.dropbox.com/s/y84av0633wvq104/T577_Glob_1.JPG?raw=1

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.


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.

https://www.smooth-on.com/ (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 :-#)#
Click to expand...

+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.
 
On Wednesday, February 5, 2020 at 8:01:34 PM UTC-5, John Larkin wrote:
https://www.dropbox.com/s/y84av0633wvq104/T577_Glob_1.JPG?raw=1

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
Click to expand...

What does this say?

https://www.thomasnet.com/products/encapsulation-potting-services-1791-1.html
 
On Wednesday, February 5, 2020 at 8:01:34 PM UTC-5, John Larkin wrote:
https://www.dropbox.com/s/y84av0633wvq104/T577_Glob_1.JPG?raw=1

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.
Click to expand...

Someone mentioned Silicone RTV in another thread. (I know there are two
types of 'curing' ingredients.. ammonia and something else.
(Acetoxy)
https://www.gluegun.com/blogs/news/88695364-rtv-silicone-a-comprehensive-overview-and-product-guide

George H.
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
Click to expand...
 
John Larkin wrote:
https://www.dropbox.com/s/y84av0633wvq104/T577_Glob_1.JPG?raw=1

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.

Thin the glop first, then spray it on?
Click to expand...
 
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