During the SMT (Surface Mount Technology) process for circuit boards, there are often specific areas that need to be protected from processing while the board undergoes a single-pass reflow soldering operation. Masking tape is used to shield these areas. While polyimide is a common choice, the market offers various other masking tapes-such as those made from masking paper (crepe paper), PET, or foam-each with its own advantages for PCB and FPC applications.

The polyimide tape discussed here features an amber-colored base material. Its standout characteristic compared to other masking tapes is its superior high-temperature resistance; it can typically withstand temperatures up to 290°C-approximately 100°C higher than PET or masking paper tapes. This higher temperature tolerance accounts for its increased cost. Nevertheless, polyimide tape is widely used in PCB manufacturing processes, whereas masking paper tape-being more cost-effective-is primarily used for low-temperature masking applications, such as automotive painting or interior renovation painting.

Another key feature of polyimide tape is its anti-static capability, which can be provided on either one side or both sides. This attribute gives it an advantage over other tapes, as effective anti-static properties help extend the lifespan of electronic components.

Polyimide tape is manufactured by coating a polyimide (PI) substrate with a silicone pressure-sensitive adhesive; double-sided versions also include a release liner. It leaves no residue after high-temperature exposure, complies with RoHS standards, and is most commonly available in amber or black.