Thin, stress-balanced insulating substrate for mounting semiconductor devices

摘要

An insulating substrate for mounting semiconductor devices that is composed of a thin flat plate of inexpensive alumina (Al2O3) preferably in the range of 0.26 to 0.29 mm in thickness. Copper foil sheets are applied to both sides of the flat plate with edges spaced a distance back from the end surface of the plate to increase air path distance between the edges of the sheets of foil applied to opposite sides of the plate. The difference in distance between the end surface of the alumina plate and the edges of each copper foil is 0.5 mm or less to balance thermal stress upon heating and cooling of semiconductors soldered to the copper foil.