Ingot plate made of thermoelectric material, rectangular bar cut from the ingot plate, and process of fabricating the ingot plate

摘要

PCT No. PCT/JP98/00036 Sec. 371 Date Aug. 12, 1998 Sec. 102(e) Date Aug. 12, 1998 PCT Filed Jan. 8, 1998 PCT Pub. No. WO98/31056 PCT Pub. Date Jul. 16, 1998An ingot plate (10) of cleaveable thermoelectric material has a layered structure having substantially parallel cleavage planes. Substantially all of the cleavage planes are disposed at a less cleavage angle with respect to the upper and lower faces (11, 12) of the plate. The ingot plate can be successfully cut into bars (20) along cutting planes generally perpendicular to the cleavage planes without causing substantial interlayer fracture. Electrodes (25) are formed on the opposite sides of the bar which are defined by the cutting planes. The bar is in use to be cut into a number of discrete chips (30) with one of the electrodes fixed on a substrate. Since the cutting is made along planes again generally perpendicular to the cleavage planes of the bar, the bar can be successfully cut into the corresponding chips without causing any substantial fracture. The ingot plate is fabricated by the use of a mold having a mold cavity (63) and an elongated slit (75) which extends from the cavity to a distal end within the mold. After a molten material is filled within the cavity and also in the slit, crystallization of the material starts from the distal end of the slit along the slit and proceeds in the cavity in substantially the same direction, thereby giving the layered structure to the ingot plate.