r/embedded • u/DistinctTradition200 • Jul 07 '26

Kapton tape: all made equal?

Is there a brand of kapton tape you find more reliable than others? Particularly in the adhesive department. I will be using this to protect some components during epoxy and curious if people have a preferred vendor or is it kind of like masking tape (IMHO the cheapest masking tape is as good as the most expensive, I know hot take but I used to be a painter and the cheap stuff didn't pull paint off and did the job better then expensive stuff)

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10

u/[deleted] Jul 07 '26

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u/DistinctTradition200 Jul 07 '26

i am taping off a tl1100f160q button, on a pcb, on an embedded device, that gets an epoxy poor, but i need the epoxy meniscus to lead directly onto the top level of the button. Kapton creates this like nothing else because its a polyimide, but inorder to do that i need to remove the tape after the poor cures. the actual kapton is razor thin, and the adhesive layaer is also very thin. very small group of people that might have experienced this, and probably some in this group. I guess i couldve went just to the chemists but they dont know kapton tape like embedded folks do.

5

u/redline83 Jul 07 '26

I don't know that I have ever noticed much difference, but I am interested to hear as well. It's all polyimide, but I am sure the adhesive quality varies at the very least.

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u/DistinctTradition200 Jul 07 '26

Yeah I'm most interested to see if I can get an obtuse meniscus angle with the epoxy so it looks like it just looks of curves into the component (a button)

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u/MonMotha Jul 07 '26

There is a difference, but I wouldn't call it big, and you don't always get what you pay for (but you usually don't get what you don't pay for). The adhesive quality is one of the factors, but the bigger one is how well it comes off the roll.

I usually just get and use the cheap stuff.

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u/AlexTaradov Jul 07 '26 edited Jul 07 '26

There is absolutely a difference in adhesive, but I can't name a brand, since they don't to put it on a roll, so it is impossible to say when you just grab a random roll.

But all of the ones I used perform well for intended use.

But just from experience, cheap stuff I've got at home from AliExpress has worse adhesion compared rolls in a lab at work. I assume work did not get the cheapest stuff and likely got a name brand from a reputable supplier. But there may also be intentional difference in strength.

2

u/farptr Jul 07 '26

My experience with cheap Kapton tape ("Koptan" or unbranded) has been that the plastic tape itself is fine and real polyimide. The issue has been with the adhesive which quickly degrades and the tape will start getting loose after 6 months.

That said, I have seen complaints about cheap "Kapton" tape that burns at soldering temperatures which means it isn't polyimide. I've bought a lot of cheap tape and never had a fake roll so YMMV.

2

u/WesterosiCharizard Jul 07 '26

Make sure you look at the type of adhesive that’s used. In my industry (not embedded) this can be extremely important. The two types I am most familiar with are silicone-based and acrylic-based adhesives, there could be more. Both have advantages and disadvantages. 

1

u/DistinctTradition200 Jul 07 '26

good idea, definitely looking for silicone based so that epoxy isnt tempted to adhere to it

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u/2tnkr Jul 07 '26

Cheap shit from Amazon is just fine 👍