View Single Post
Old 06-30-2017, 12:28 AM   #3
HarryN
 
Join Date: May 2010
Location: Pleasanton, CA
Posts: 2,680
Thanks: 659
Thanked 871 Times in 708 Posts
Default Re: Unexpected response from 3M about VHB 4950 tape for rigid solar panels

There is quite a large thermal expansion mismatch between fiberglass and aluminum. In addition, the solar panel mounts will experience quite large thermal cycles each day.

I wonder if their recommendation for a version with a thicker, more compliant version is related to buffering this cyclical thermal expansion effect?

About 15 years ago I was experimenting with mechanically and thermally bonding the LED thermal mount points to a combination electrical / thermal substrate. I tested several adhesives fairly aggressively and two things became very obvious:
- The surface preparation and pre clean effect was greater than the difference between the adhesives I tested.
- The lower spec but more mechanically compliant adhesive performed substantially better than the stronger, more rigid one - in mechanical shock testing.

Last edited by HarryN; 06-30-2017 at 12:30 AM.
HarryN is online now   Reply With Quote
The Following 3 Users Say Thank You to HarryN For This Useful Post:
Nomad_Elvis (06-30-2017), rdvan@sbcglobal.net (08-25-2017), woodywesty (11-26-2018)