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PCB Adhesive

by johnnyc on Sat Jul 28, 2012 5:55 pm

I run a small company, Dexter Industries. We started out a few years ago making a few sensors for LEGO MINDSTORMS. Our sensors for the LEGO system are pretty bare-bones: they're mostly all just PCB's. Some have proven popular, but the feedback we get from our customers and distributors is to get some sort of protective casing on them.

I've been experimenting with Laser Cut acrylic, sort of a sandwich model where a supporting base is cut to go around the circuitry, a cover on one end, and the PCB on the other. This seems like a really inexpensive, easy-to-implement casing (plastic blow molding is currently way out of our budget).

The problem I'm having is getting the acrylic to adhere to the PCB. The two acrylic pieces go together great with acrylic cement (pretty obvious I guess). I can't seem to find a good glue to bring the acrylic to the PCB.

Maybe I'm totally barking up the wrong tree to get some protection for the sensors as well; has anyone else had this problem or thought about it?
John Cole
http://www.dexterindustries.com
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Re: PCB Adhesive

by adafruit_support_mike on Sat Jul 28, 2012 10:03 pm

Cyanoacrylates (superglue) should work. It's compatible with acrylic, and won't bother the epoxy in an FR4 circuit board.

You might also consider potting the PCB in resin. You can use the polystyrene/polyurethane stuff you'll find in the automotive section for use with fiberglass, or get the good stuff from places like these:

http://www.alumilite.com/Category.cfm?C ... g%20Resins
http://www.smooth-on.com/Industrial/c1275/index.html

Potting takes less work than machining an enclosure, and the resins are affordable.. a couple hundred bucks in gallon quantities (which will pot a lot of boards).
Last edited by adafruit_support_mike on Tue Jul 31, 2012 2:09 am, edited 1 time in total.
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Re: PCB Adhesive

by johnnyc on Mon Jul 30, 2012 8:41 am

Thanks! I'll give it a shot today!
John Cole
http://www.dexterindustries.com
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Re: PCB Adhesive

by johnnyc on Mon Jul 30, 2012 3:18 pm

This was a fantastic idea!

Just for future reference, this is a great way to add PCB protection for low-volume applications.

I used Ponoko to cut out two layers of acrylic: one layer serves as a collar around the electronics on a circuit board I wanted protected (a collar or standoff middle layer), and the other as the actual cover. The acrylic you choose for the middle layer must be thicker than your electronics are high. You can mount the two acrylic layers together with model glue (maybe super-glue as well) and the acrylic can be mounted to the PCB with superglue.

When you're designing the circuitboard, you

Pretty easy and fantastic way to protect your circuit boards!
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http://www.dexterindustries.com
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Re: PCB Adhesive

by Jack52 on Wed Aug 08, 2012 4:05 pm

Goop Plumbers Adhesive is great and will stick just about anything to anything:

http://www.pacoa.com/goop-plumbers-adhe ... -1502.html

It stays very slightly flexible so that it is very stable against vibration and abuse for the long term.

I buy it at Lowes or Home Depot

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