Material Properties
Typical Properties of Dielectric Material for Flexible Printed Circuitry
| Property (Typical) | Units | Polymide | Polymide (Adhesiveless) |
Polester |
| Representative Trade Name | KAPTON | KAPTON | MYLAR | |
| Physical | ||||
| Thickness Range | mil | 0.5 to 5 | 1-6 | 2-5 |
| Tensile Strength (@25°C) | psi | 25,000 | 50,000 | 20,000 to 35,000 |
| Break Elongation | % | 70 | 50 | 60 to 165 |
| Tensile Modulus (@25°C) | 100,000 psi | 4.3 | .7 | 5 |
| Tear Initiation Strength | lb/in | 1000 | 700-1200 | 1000 to 1500 |
| Tear Propagation Strength | g/mil | 8 | 20 | 12 to 25 |
| Chemical | ||||
| Resistance to: | ||||
| Strong Acids | Good | Good | Good | |
| Strong Alkalis | Poor | Good | Poor | |
| Gease and Oil | Good | Good | Good | |
| Organic Solvents | Good | Good | Good | |
| Water | Good | Good | Good | |
| Sunlight | Good | Good | Fair | |
| Fungus | Non-nutrient | Non-nutrient | Non-nutrient | |
| Water Absorption | % (24 hours) | 2.9 | 0.8 | <0.8 |
| Thermal | ||||
| Service Temperature (min/max) | degree C | -125/+200 | -125/+200 | -60/+105 |
| Coefficent of Thermal Expansion (@22°C) | PPM/degree C | 20 | 20 | 27 |
| Change in Linear Dimensions (100°C, 30min) | % | <0.3 | 0.04-0.02 | <0.5 |
| Electrical | ||||
| Dielectric Constant (ASTM D150) 1MHz | 3.4 | 3.4 | 3 | |
| Dissipation Factor (ASTM D150) 1MHz | 0.01 | 0.003 | 0.018 | |
| Dielectric Strength (ASTM D149) @ 1 mil thickness Volume Resistivity (ASTM D257) |
V/mil ohm-cm |
6000 1.0E+16 |
6000 1.0E+16 |
3400 1.0E+16 |