The Interez glass fiber composite has a coefficient of thermal expansion of 6.3 cm/cm/ DEGC..times.10@6.
Typically, the glass fiber substrate is about 3 to about 5 mils thick and preferably about 3 to about 4 mils thick typical of which is about 4 mils.
Such glass fiber reinforced plated copper composite sheets having low coefficient of thermal expansion are especially useful as power cores in the fabrication of multilayer chip carrier cards having both the dielectric layers or signal core and the power core matches in thermal expansion coefficient.
The glass fiber yarn which contains a plurality of continuous glass filaments is impregnated with a sol-gel precursor.
For example, the coefficient of thermal expansion of a printed circuit board fabricated with E-glass fiber reinforced by an epoxy matrix polymer is about 17 cm/cm/ DEGC..times.10@6.
The present invention is concerned with a method for fabricating a composite substrate and is particularly concerned with fabricating glass fiber-reinforced polymer based composite substrates that have relatively low coefficients of thermal expansion.