The Properties and Applications UPILEX-S Polyimide Films

UBE offers UPILEX-S polyimide films with fantastic resistance to heat and chemicals over a broad temperature range. They have a UL94 flammability rating of VTM-0 and have no melting point. Their mechanical properties are superior to other currently available products on the market.

Key Properties of UPILEX-S Polyimide Films

The tensile modulus of UPILEX-S polyimide films is 9121MPa, which is more than double the value of an earlier version of the product. The tensile strength of this material is 520MPa. The UPILEX-S polyimide film experiences very little degradation in these properties at elevated temperatures, making it suitable for use in extreme temperature applications. The dimensional stability of the UPILEX-S polyimide film is much better than other competitive products.

In addition, this polyimide film has very low hygroscopic expansion, heat shrinkage and linear expansion. Besides having high tensile strength and modulus, the UPILEX-S polyimide film exhibits superior long-term heat resistance. Its resistance to hydrolysis is very high as it virtually retains its properties even when immersed in boiling water for prolonged periods.

The thermal resistance of the UPILEX-S polyimide film is much higher than any other currently available plastic films. The very small thermal linear expansion coefficients and heat shrinkage values of the UPILEX-S polyimide film enable using the material in FPC and TAB-tape substrates containing minute circuits.

This material shows good resistance to virtually all chemicals, including alkali and inorganic acid solutions, and is insoluble in all types of organic solvent. There is no change in the dimensional stability and physical properties of the UPILEX-S polyimide film even when subjected to chemical exposure.  As a result of its good chemical resistance, the UPILEX-S is suitable as release film, even without a release agent.  

Table 1 summarizes the typical properties of the UPILEX-S and UPILEX-SN polyimide films.

Table 1. Properties of UPILEX-S and UPILEX-SN

UPILEX-Properties Unit 12.5SN 25S 50S 75S 125S Test Method
Tensile Strength MPa MD: 618 MD: 552
TD: 547
MD: 427
TD: 414
MD: 347
TD: 337
MD: 330
TD: 321
Elongation % MD: 64 MD: 48
TD: 47
MD: 40
TD: 45
MD: 48
TD: 51
MD: 52
TD: 53
Tensile Modulus GPA MD: 9.4 MD: 9.4
TD: 9.3
MD: 8.5
TD: 7.9
MD: 6.9
TD: 6.7
MD: 6.7
TD: 6.5
Folding endurance cycles >100000 >100000 >35000 >24000 >2000 ASTMD2176
Break Down Voltage kV 3.4 6.4 10.8 10.0 13.4 ASTM D149
Dissipation Factor - 0.0044 0.0041 0.0026 0.0025 0.0031 ASTM D150
Dielectric Constant - 3.5 3.3 3.3 3.3 3.5 ASTM D150
Volume Resistivity Ω cm >1016 > 5 *1016 > 6 *1016 > 4 *1016 > 1016 ASTM D257
CTE (anneal, 50-200°C) ppm/K MD: 9
TD: 9
MD: 11
TD: 10
MD: 14
TD: 17
MD: 19
TD: 22
MD: 19
TD: 22
Heat Shrinkage (200°C, 2h) % 0.04 MD: 0.09
TD: 0.05
MD: 0.02
TD: 0.01
MD: 0.03
TD: 0.01
MD: 0.03
TD: 0.01
JIS C2318


The properties of the UPILEX-S polyimide films make them the material of choice in a variety of applications, including:

  • Electrical isolation
  • Heating film
  • Flexible printed circuits
  • Separation film
  • Release film

This information has been sourced, reviewed and adapted from materials provided by UBE Group.

For more information on this source, please visit UBE Group.


Please use one of the following formats to cite this article in your essay, paper or report:

  • APA

    UBE Group. (2019, May 07). The Properties and Applications UPILEX-S Polyimide Films. AZoM. Retrieved on June 02, 2023 from

  • MLA

    UBE Group. "The Properties and Applications UPILEX-S Polyimide Films". AZoM. 02 June 2023. <>.

  • Chicago

    UBE Group. "The Properties and Applications UPILEX-S Polyimide Films". AZoM. (accessed June 02, 2023).

  • Harvard

    UBE Group. 2019. The Properties and Applications UPILEX-S Polyimide Films. AZoM, viewed 02 June 2023,

Tell Us What You Think

Do you have a review, update or anything you would like to add to this article?

Leave your feedback
Your comment type