Abstract: A contact shim for insertion between an electrode internal contact member and a contact surface of a semiconductor element in a semiconductor device assembly. The shim has a generally continuous body (2) provided with a number of apertures (4, 5, 6, 7) having a land (1) or finger extending at least partially thereacross, preferably a land comprises a bar which bisects an aperture (4, 5, 6, 7). The apertures and bisecting lands may be used as visual guides in aligning the shim with reference marks on the contact surface of the semiconductor element and, the means of attaching the shim to the element may be applied to the lands in order that any distortion consequent upon attachment is confined to the lands leaving the body of the shim undistorted.