HEAT-RADIATION STRUCTURE FOR MULTI-LAYER SUBSTRATE

摘要

PROBLEM TO BE SOLVED: To improve the heat-radiation characteristics of a multi-layer substrate where heating elements are mounted in high density, and to reduce a cost with no heat-transfer plate or heat sink. SOLUTION: A multi-layer substrate 2 comprises an inner-layer insulating layer 10, internal heat-transfer layer 21, surface-layer insulating layer 31, and via hole 50 which electrically connects a heating element 90 to the internal heat-transfer layer 21. These layers are sequentially laminated and molded by a build-up method. The heat from the heating element 90 is transferred to a case 80 in which the multi-layer substrate 2 is housed from the internal heat-transfer layer 21 through the surface-layer insulating layer 31.