About Films

xxPolyonics manufacturers tapes, label materials and flexible substrates that include polyimide (PI), polyester (PET), Nylon, aluminum,  polyethylene naphthalate (PEN), polyetherimide (PEI), polyether ether ketone (PEEK), and Nomex films.  The films are specifically selected for their ability to survive harsh environments including high temperatures and exposure to chemicals. The materials continue to protect, mask, identify, insulate, isolate and bond heat and static sensitive devices as well as help prevent the propagation of fire.

The film portion of the construction is a major factor in determining the material’s overall physical properties. These include tensile strength, thermal, UV, chemical and electrical resistances, thermal conductivity, surface roughness, dimensional stability, stiffness, ease of die cutting, etc. Depending on the type of film used and the application, it can account for up to 70% of the overall product cost with higher performances relating to higher film costs.


The three most popular materials used in the Polyonics product lines are PI, PET and aluminum.

PI is the primary film used by Polyonics due to its superior performance in harsh environments. Polyimide has the ability to remain dimensionally stable at temperatures up to 500° C (1000°F) as well as to resist prolonged exposures to chemicals typical of the PCB manufacturing process. PI is also a highly rated flame retardant material.

PI films are available in amber and semi gloss black. The films must be coated with an opaque top-coat for printing applications such as high resolution bar codes on PCB labels. PI is available in 13µm (0.5mil) to 125 µm (5mil) thicknesses.

PET is a more economical film than PI and has lower performance values as well. PET is available in white or clear and in 25µm (1mil) and 50µm (2mil) thicknesses. It’s rated for 300°C (572°F), has a lower dielectric strength, is less dimensionally stabile and offers a lower UL94 flame retardant rating.
Aluminum is available in 50µm (2mil) thicknesses and is applicable to a wide array of applications that require prolonged exposure to extreme temperatures. These include tags, labels and tapes for use on furnaces and in foundries and low temperature, cryogenic labels, etc. Additional tape applications include vapor barriers, RFI and EMI absorption and isolation, heat radiation and high temperature fire prevention.