Adhesive tape for electronic parts

DETAILED DESCRIPTION The adhesive tape for electronic parts of the present invention is characterized by comprising two adhesive layers which are composed of 100-40% by mol of at least a polyimide comprising at least one of the repeating units represented by the following formulas (1a) and (1b) and 0-60% by mol of at least one of the repeating units represented by the following formulas (2a) and (2b), said two adhesive layers being laminated each other and having each a different glass transition temperature: ##STR2## wherein Ar represents a divalent group selected from the following formulas containing aromatic rings: ##STR3## wherein R.
sub.
1, R.
sub.
2, R.
sub.
3 and R.
sub.
4 which may be identical or different represent each a hydrogen atom, an alkyl group having 1-4 carbon atoms or an alkoxy group having 1-4 carbon atoms, provided that R.
sub.
1, R.
sub.
2, R.
sub.
3 and R.
sub.
4 are not hydrogen atoms at the same time.
##STR4## wherein R is an alkylene group having 1 to 10 carbon atoms or --CH.
sub.
2 OC.
sub.
6 H.
sub.
4 --, the methylene group of which attaches to Si, and n means an integer of 1 to 20.
In the adhesive tape for electronic parts of the present invention, two adhesive layers which are laminated each other and have each a different glass transition temperature mean those which are composed of an adhesive layer having a higher glass transition temperature and a lower glass transition temperature.
It is preferred that the difference of the glass transition temperature of these two adhesive layers is at least 40.
degree.
C.
In the adhesive tape for electronic parts of the present invention, it is preferred that at least one of the adhesive layers contains a filler having a particle size of not more than 1 .
mu.
m in an amount of from 0.
1 to 50% by weight and it is possible to provide a releasing film on a surface of at least one of the adhesive layers.