| 摘要 |
<p>A polyimide which is a random copolymer having repeating units represented by the general formula (1) (1) (wherein R1 and R2 may be the same or different and each represents a divalent group selected among x is 0.60 to 0.80, y+z is 0.40 to 0.20, and x+y+z is 1.00) and which has a coefficient of linear expansion of 10 to 20 ppm/K in the range of 100 to 200°C. The polyimide is useful as a polyimide circuit substrate material which prevents layered materials from shrinking or expanding and has excellent smoothness.</p> |
