Recently I bought a Flirc case for my Raspberry Pi 4. I liked it so much that I also ordered Flirc cases for my two other Raspberry Pi 3B+'s. So far so good.
Before arrival I watched a couple of unboxing reviews on Youtube. In the more recent videos I saw there were 2 thermal pads supplied with the case. One for the 2B/3B and a thinner one for the 3B+ because it has a taller chip.
After arrival I saw there was only 1 thermal pad supplied with each case. According to the store's website (TinyTronics.nl) it's now only compatible with the newer 3B and the 3B+ with the taller metal chip.
On this forum I found the thermal pad thickness should be 0.4 mm:
However, I did measure it with calipers and the thickness is 1.13 mm with the plastic and paper still on. After removing those I measured those and combined they are 0.13 mm. So the thermal pad is 1.0 mm exactly.
Despite all of this my Pi 3B+ doesn't fit in the case. When inserting the board into the case with the HDMI-port side first and pushing the board down, the ports grab into the case cutouts and won't let me push it all the way down. I feel resistance because the leverage and the GPIO side on the board hovers a couple of mm above the screw holes and the USB ports are inaccessible that way. Pushing it down any further would break stuff.
TinyTronics told me they tested it with a 3B+ and they have no issues. They also told me that Flirc now ship the cases with a single thermal pad that fits all 2B/3B(+) Pi's. In my situation that's not the case unfortunately.
I was thinking of what the cause could be. The issue might be different batches of the Pi 3B+ from different factories/countries over the past couple of years. One with a taller chip than the others. Or with a thicker layer of solder? I also mentioned this to TinyTronics.
Finally I tested it with scotch tape. I used multiple layers and ended up with 0.4 mm. This is the correct and desired thickness. But where can I find 12x12 mm pads with 0.4 mm thickness? Preferably the original ones that once were supplied by default with the Flirc cases in the recent past.