[sdiy] Need a TO220 thermo pad that can withstand 130vdc without arcing..

[Didrik Madheden]

What's the sigh about? The answer didn't seem to contain any too
egregious errors for that product.
Breakdown Voltage: >4kV seems like a reasonable answer when there are
two variants, of which one exceeds that figure, and the requirement
was one order of magnitude lower than either of the product variations
anyway.
Thermal Conductivity: 1.1 W/m-K seems like a reasonable answer when
the product exceeds this specification at 0.9 W/m-K according to the
datasheet. (1.1 W/m-K is probably a real figure too that it picked
from somewhere online. Perhaps for some slightly different test
procedure, such as lower pressure than specified in  ASTM D5470.)
The corrected answer seems to contain values copy pasted directly from
the datasheet. I'd say ChatGPT did a reasonable job, actually.

On Wed, 29 Jan 2025 at 22:00, Ben Stuyts via Synth-diy
<synth-diy at synth-diy.org> wrote:
>
> And upon checking the Sil-Pad and pointing out that the specs were in error:
>
> "Apologies for any confusion in my earlier response. Upon reviewing the specifications for Bergquist Sil-Pad 400, here are the accurate details:
>
> Breakdown Voltage:
> 0.007-inch thickness: 3,500 VAC
> 0.009-inch thickness: 4,500 VAC
> Thermal Conductivity: 0.9 W/m-K
> Operating Temperature Range: -60°C to +180°C
> Given your requirement for a thermal pad that can withstand 130 VDC without arcing, the Sil-Pad 400's breakdown voltage ratings are more than sufficient. For instance, the 0.007-inch version can handle up to 3,500 VAC, which is significantly higher than 130 VDC. Additionally, this silicone-based pad does not require any thermal compound, aligning well with your preferences.
>
> Therefore, Bergquist Sil-Pad 400 should be a suitable choice for your application.”
>
> Sigh…
>
> Ben
>
>
> On 29 Jan 2025, at 21:51, Ben Stuyts <ben at stuyts.nl> wrote:
>
> I’m having fun asking these kind of things on ChatGPT 4o, so beware, the following is unverified :-)
>
> “For a TO-220 package that needs to withstand 130VDC without arcing and without using mica or thermal compound, silicone-based thermal pads are an excellent choice. These pads provide electrical insulation while maintaining good thermal conductivity.
>
> ### Recommended Options:
> 1. **Bergquist Sil-Pad 400**
>    - Breakdown Voltage: >4kV
>    - Thermal Conductivity: 1.1 W/m-K
>    - Operating Temperature: -60°C to +180°C
>    - No additional compound required
>
> 2. **3M 5590H**
>    - Breakdown Voltage: >5kV
>    - Thermal Conductivity: 3.0 W/m-K
>    - Operating Temperature: -60°C to +150°C
>    - Self-adhesive and no compound needed
>
> 3. **Keratherm Red T-441**
>    - Breakdown Voltage: >6kV
>    - Thermal Conductivity: 1.8 W/m-K
>    - Operating Temperature: -40°C to +200°C
>    - High electrical insulation and no compound required
>
> These materials are widely available from electronics distributors like Digi-Key, Mouser, or RS Components. When choosing a thermal pad, ensure that it meets your thermal dissipation needs in addition to the voltage requirements.”
>
> Ben
>
>
> On 29 Jan 2025, at 19:58, Jean-Pierre Desrochers via Synth-diy <synth-diy at synth-diy.org> wrote:
>
> Need a TO220 thermo pad that can withstand 130vdc without arcing..
> I sillicon made type that does not need any compound would do best.
> No mica/compound stuff.
> I searched on Digikey and they have a lot available but nothing stated
> about their voltage breakdown..
>
> Any idea ?
>
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-- 
/Didrik