Seeking Thermal Insulator & Electrical Insulator for Peltier Device

[Kvm90]

Hey all,

I'm using a peltier device for a cooling system I'm working on. The metal leads connecting the peltier to a power source keep falling off. I am looking to coat them with epoxy that must be a thermal insulator. It also MUST be an electrical insulator.

The problem I've had is that the epoxys I'm using run into the p and n doped semiconductor array and short my peltier. A viscous epoxy is much needed so that no running of the epoxy into the p and n semiconductors occurs.

Any suggestions?

Thanks!

 

[anorlunda]

Hmm, you could seal it prior to the epoxy, but the sealant may cause trouble also.

Make a dummy 3D model of your device including the leads. Cover it in wax. Coat it with epoxy. When the expoxy dries, pull the expoxy off. It will come off because of the wax. Then this hardened "glove" should slip on over the leads of your device.

 

[Tom.G]

If the problem occurs when applying the eopxy, you could let your existing epoxy partially set before applying it to the Peltier module.

 

[DaveE]

There are about a million different kinds of epoxy formulations. They are as common place in the electronics industry as copper. For example, the black plastic that encapsulates ICs is an epoxy resin variant. I am surprised that the ones you've tried are conductive, that is an unusual configuration for these resins. Anyway, I can pretty much guarantee that there is one that will work and be easy to use. The problem is selecting one of the many options.

Frankly, I'm kind of surprised every time I read a question like this in these forums, when the answer clearly lies with people who know enough about epoxies to name at least 10 different flavors. That's not us.

1) Try google.com, there's a lot more useful information there about specific products and common engineering solutions. Look at the manufacturers of the products you are curious about and read the technical information they have posted.

2) Call or email (calling is better IMO) the applications engineers at one of the many epoxy manufacturers. Here's one place you can start with:
https://www.masterbond.com/techtips/optimizing-electrical-electronic-insulation-properties-epoxies

3) For questions about TEC installation and use, you can call TEC manufacturers, like Marlow.
https://blog.marlow.com/topic/technical-library

Notice on both of the pages I linked to they have prominently displayed their contact phone number. It's their job to help you choose the right product. They want you to call them.

 

[DBO]

Your epoxy is electrically conductive? That's weird. Try Torr-Seal, expensive but viscous and non-conductive and excellent in vacuum.
You also might try that stuff advertised on late night that is a glue material that is cured with a UV LED. Put in on upside down, cure it and then right side up.