Aluminum PCB safe temperature range without risk of delamination?

[XOIIO]

Hi all, so this is a bit of an odd question, but I've been stuck with a new 750w silicone heater for my 3d printer hoping to upgrade the bed for a couple months now.

Unfortunately, finding a place to cut a new bed out is difficult, nay, impossible, and the thing I really wanted to do was get a sheet of mic tooling plate, however, it's only available in a thicker size than my current bed, which means that it would weigh 4lb apparently, a good chunk higher than my current print bed, and I was hoping to reduce moving mass, not increase it, since my printer has always struggled with ringing.

So, I'm considering just slapping the new heater on top of the old aluminum pcb one that's built into the print bed. This is to help with some adhesion issues with ABS, but also because I want to explore some higher strength filaments with higher temp requirements. Also speeding up heating times is going to be really really nice.

Before I risk ruining a $90 heater by making a mistake, I wanted to check as I am a bit concerned, is there much risk of aluminum circuit boards delaminating or separating with extended use at high temps, say up to 150c? The stock bed is rated at a max of 100, but that's likely mainly because it's 24v and struggles to even reach that temp.

I'm sure there are different grades and ratings of aluminum pcbs, but I'm having trouble finding what the basically lowest quality ones would be rated at for maximum temperature consistently.

[thm_w]

Depends on the grade of FR4 they used. Low stuff would be Tg of 130C, mid 140-150C, high 170C+. Garolite (FR4) from mcmaster is specced as 130 C.
Looks like this company has 100-180C for example: https://www.epectec.com/pcb/aluminum-circuit-boards.html

I would be tempted just to use it. Whats the highest, PEEK bed temp says 120C. I can't imagine anything printing on 150C?
Could also use glass instead of aluminum.


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