Thermomechanically compensated circuit board has stiff insert at one or more positions whose coefficient of thermal expansion is different from that of circuit board material

摘要

The circuit board (1) has a stiff insert (2) at one or more positions whose coefficient of thermal expansion is different from that of the circuit board material, so that the coefficient of thermal expansion of the circuit board at this point(s) is different from that at points without the insert. The coefficient of thermal expansion of the circuit board at an insert position is in the range 3 to 9, preferably 4 to 6 x 10<->6 per degree C