Thermal Insulators

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
Yeah, I was looking at some 2MIL Kapton which is fine for the PS and D class outputs but this is a class A/B and I couldn't find the Kapton 200MT (I know McMaster-Carr has them but I have not set up an account and did not want to incur additional shipping charges). I will be e-mailing J&R in the future, I have a 14 amps I'm working on right now and would LOVE to have an insulator that I could cut into strips.

It's an MA Audio HC-400 and it has most of it's mica insulators but some are missing so I was going to reuse what it has now and use these insulators as well.

You should've seen this thing when I got it. It had all blown IRFZ44Ns and someone installed a rectifier and 2 FETs I've never seen before mixed in with all the blown Z44Ns. I had a good laugh, then realized their mismatched FET burned the gate drive traces. I'm sure whoever did this thought, "Hey, they fit, let's see if it works!" What a pain. I'm surprised they didn't try to solder them in with a cigarette lighter.
 
Last edited:
Thermally conductive, electrically insulating.
 

Attachments

  • thermalpads01.jpg
    thermalpads01.jpg
    235.5 KB · Views: 110
Here is some 12 X 12 sheet Sil-Pad material, says its 6 mil though. You might want to check thermal conductivity at that thickness before buying :
Bergquist SIL-PAD 12x12 Sheet Q-2 Semiconductor Mount | eBay

You can also use Kapton Tape also on ebay ~ 2 mil or even 1mil. I have pre-cut Kapton T0-3 and T0-220 insulators on hand. The only difference is the tape has the silicon based adhesive used on one side for adhesion. You will need to roll out any air pockets with a rubber roller if you use the tape products.
Like perry said, JandR has the original Kapton MT200 used in all SoundStream Class AB amps that were made in America. I have seen metal burrs cause case shorts many times though. Its easily cut but also easily damaged. Orion used Kapton tape materials in there very old school amps.

Sil-Pad is likely the best you will find and no silicon grease needed. I have several different types and on rolls I acquired. Always nice to have on hand...

Mica can be had in just about any thickness you like. I have some here clear as glass and very uniform thickness, and very thin also...They are also available from most suppliers...:)
 
Hey, thanks for the reply 1moreamp. Nice to hear from you on one of my threads. From what I've seen you have some VERY specific knowledge on certain equipment, hopefully I will be tapping into that in the future.

I plan on getting the 200MT even though I mostly fix class D amps. Most say they're more difficult but I actually have more experience with them than class A/B since they are now more prevalent and more likely to be driven beyond their capabilities. Not to mention you can see the outputs working at idle.

The insulators I received are great. It's basically sil-pad material cut to size (pain) so no thermal paste required (less pain). I just stuck them to the fets with thermal paste and mounted them directly to the heat sink without thermal paste on the other side. Amp gets nice and warm and no issues so far! I give these a +1 if you just need a couple insulators to replace lost mica insulators.
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.