Heatsink el. insulator between LED/Heatsink? - Page 1
Forum section: electronics / beginners

author: kalel
author_rank: Frequent Contributor
timestamp: January 21, 2018, 01:57:01 pm
content: I'm considering trying to make a small LED light using one of those aluminum profiles that are sold with diffusers, and then soldering LEDs onto copper tape (I know this could be a bad idea for few reasons - mainly heat ruining the glue), but just as an experiment and soldering practice. In fact, if it turns out to be too impractical, I will not proceed with this idea as is.I wanted to use either SMD LEDs like 5730, or those 1-3W ones that usually go on "star shaped heatsinks". Anyway, I can't just put copper tape on the aluminum, as I assume the heatsink aluminum it is conductive enough to cause problems even though there's an oxide layer (if my assumption is wrong, let me know).To solve the problems of tape unsticking, I would consider adding some type of glue layer to ensure things stay in place.Is there a suitable material (e.g. a tape) that I could put between the copper tape and aluminum for electrical insulation?How would you do a similar thing, beside getting LEDs that already have a heatsink or making a custom PCB with aluminum backing?

author: Belrmar
author_rank: Regular Contributor
timestamp: January 21, 2018, 02:51:45 pm
content: I am not sure because i dont have any of those LED's around here, but are you sure they arent electrically isolated?

author: kalel
author_rank: Frequent Contributor
timestamp: January 21, 2018, 02:53:49 pm
content: Quote from: Belrmar on January 21, 2018, 02:51:45 pmI might have explained incorrectly, I mean electrical isolation between the copper tapes (with LEDs soldered on) and the aluminum extruded bar heatsink (those sold cheaply for LED strips with diffuse covers). Of course it would be easier to use a premade strip.

author: Zero999
author_rank: Super Contributor
timestamp: January 21, 2018, 03:12:12 pm
content: In my experience, those star LEDs have an isolated thermal slug, underneath them, but it will only be suitable for very low voltages <50V.Is this going to be running off the mains? If so, the isolation on the heat sink is unlikely to be sufficient, even if it's earthed. Treat the heat sink as if it were live.

author: kalel
author_rank: Frequent Contributor
timestamp: January 21, 2018, 03:26:21 pm
content: Quote from: Hero999 on January 21, 2018, 03:12:12 pmIt's not going to be directly running from the mains (if made), but with an isolated power supply.

author: Kjelt
author_rank: Super Contributor
timestamp: January 21, 2018, 03:32:17 pm
content: You really have to check the led package first.Some have an isolated pad some the pad is connected to the anode or cathode, it really changes per type of led and brand.Then you would like thermal conducting, electrical isolating material.There are special brands that make such isolation material but for consumers it is hard to come by unfortunately.These feel like gummy like substances in varying thicknesses, I will have to check for manufacturer.

author: Kjelt
author_rank: Super Contributor
timestamp: January 22, 2018, 09:48:31 am
content: To come back on my promise, the manufacturer I know off is called: Bergquist.http://www.bergquistcompany.com/If you type "Bergquist" in the search bar from your favorite electronics seller such as Farnell or Digikey, a lot of products show up.

author: kalel
author_rank: Frequent Contributor
timestamp: January 22, 2018, 10:01:06 am
content: Quote from: Kjelt on January 22, 2018, 09:48:31 amI will check it, thanks.

author: Kjelt
author_rank: Super Contributor
timestamp: January 22, 2018, 09:07:34 pm
content: Possible economic alternative:https://www.robotdigg.com/m/product/1226/3M-double-sided-tape-50-meter-for-heatsink#