Waterproofing ESC

[JimClark]

Ok I have one coat of the conformal coating on my 30 amp Mystery ESC for my Microhydro. One question is that it is a single board with an aluminum plate on each side of the ESC. The plate was held on with some sort of double backed tape that is a light gray.

I assume this tape is also to insulate the alum plate from the chips. Where can I get more of this tape so I can put the ESC back together after coating the ESC?

Jim

[dana]

Jim, it is probably automotive molding tape. I paint cars and use this all the time... It's light grey. Bout 1/16 thick and super sticky rite? 3M makes it. I can get you the exact 3M part number if you want it. Comes on a large roll. And makes that white foam double sided tape look like a joke. Lemme know. Regards, Dana

[egneg]

I believe it is a material for heat transfer from the fets to the plate. I would imagine that you could use a thermal paste instead.

[domwilson]

http://www.itapestore.com/3m88052-thermaltransfertape.aspx

[befu]

thermal tape

That is the thermal tape. If you look at it when you take it off, you can see the few spots it actually touches the FET's, not very good at heat transfer. That is why a use thermal paste to a water cooled plate and then seal in epoxy.

If you want to reuse the tape, people here recommend to sand the tops of the FET's flat to get better contact with the tape. Tape is said to be better by those that know around here it seems.

Hope this helps,

Brian

Weren't you going to put this motor into a 1/16 hydro?

[JimClark]

Sounds like it

Jim, it is probably automotive molding tape. I paint cars and use this all the time... It's light grey. Bout 1/16 thick and super sticky rite? 3M makes it. I can get you the exact 3M part number if you want it. Comes on a large roll. And makes that white foam double sided tape look like a joke. Lemme know. Regards, Dana

[JimClark]

No a bigger Scorpion goes in the 1/16th hydro.

Man this tape is expensive anyone have some they would sell me a small piece?

If not I might as well junk this ESC and buy a 35 amp marine ESC it woudl be the same price.

JIm

That is the thermal tape. If you look at it when you take it off, you can see the few spots it actually touches the FET's, not very good at heat transfer. That is why a use thermal paste to a water cooled plate and then seal in epoxy.

If you want to reuse the tape, people here recommend to sand the tops of the FET's flat to get better contact with the tape. Tape is said to be better by those that know around here it seems.

Hope this helps,

Brian

Weren't you going to put this motor into a 1/16 hydro?

[domwilson]

http://cgi.ebay.com/Lot-2-1-5-x-1-5-Thermal-Tape-/390079248313?cmd=ViewItem&pt=LH_DefaultDomain_0&hash=item5ad288f7b9#ht_500wt_928

[JimClark]

Just found this

http://cgi.ebay.com/Sekisui-5760-Thermal-Adhesive-Tape-8-X1-3-strips-2ft-/180502163279?cmd=ViewItem&pt=LH_DefaultDomain_0&hash=item2a06c46f4f

[egneg]

Just go to Radio Shack and get some thermal paste.

[m4a1usr]

Just go to Radio Shack and get some thermal paste.

Silicone thermal paste does not transfer heat very well if applied in a thick application. It must be a thin uniform coating to work. Lots of data to back this up. The heat transfer foam was designed to overcome the issues with uneven surfaces like FET's soldered on to a board. They get wave soldered and are not all parallel to the heat sink surface uniformly.

Most importantly over time,...as the heating cycles continue, on the FET surface the silicone oil can actually leak away from the white metal oxides and they dry out. Leaving voids or areas with air. These are excellent insulators! Not conductors.

The foam, whether with an adheisive or simply compressed between the FET's and a metal plate will conduct heat better over time. If you have a business go to the 3M web site and request a thermal pad kit for engineering development. I got mine earlier this year and they give you enough foam to use on 5 or 6 2x3 plates.

I used to use the thermal grease myself exclusively on my speedos. Then did some research and found that on these mass production speedos have issues with the FET boards and uniformity. Try this;http://cgi.ebay.com/Thermal-Adhesive...item27b1a8f640

John

[domwilson]

Silicone thermal paste does not transfer heat very well if applied in a thick application. It must be a thin uniform coating to work. Lots of data to back this up. The heat transfer foam was designed to overcome the issues with uneven surfaces like FET's soldered on to a board. They get wave soldered and are not all parallel to the heat sink surface uniformly.

Most importantly over time,...as the heating cycles continue, on the FET surface the silicone oil can actually leak away from the white metal oxides and they dry out. Leaving voids or areas with air. These are excellent insulators! Not conductors.

The foam, whether with an adheisive or simply compressed between the FET's and a metal plate will conduct heat better over time. If you have a business go to the 3M web site and request a thermal pad kit for engineering development. I got mine earlier this year and they give you enough foam to use on 5 or 6 2x3 plates.

I used to use the thermal grease myself exclusively on my speedos. Then did some research and found that on these mass production speedos have issues with the FET boards and uniformity. Try this;http://cgi.ebay.com/Thermal-Adhesive...item27b1a8f640

John

Correct. The silicon paste will turn to a chalky substance over time.

[ON THE FARM]

Do not replace thermal tape with thermal paste!
just replace it, or if it is not real dirty reuse it.

[JimClark]

I bought some Sekisui 5760 Thermal Adhesive Tape off ebay