Semiconductor module and heat sink used in such module

A heat sink adapted to be used for a semiconductor module, said heat sink comprising:

• a pair of same or symmetrical metallic plates between which a circuit board, having at least a pair of attachment holes, is to be disposed in such a manner that spaces are defined between said circuit board and said pair of metallic plates for accommodating semiconductor elements or semiconductor devices mounted on said circuit board, when said pair of metallic plates are attached to said circuit board;
• each of said metallic plates being provided at one position, corresponding to one of said pair of attachment holes, with a through hole and at another position, corresponding to the other attachment hole, with a tubular projection having a length larger than a sum of a thickness of said circuit board and a thickness of the metallic plate;
• and
• said tubular projections of the respective metallic plates being insertable into said corresponding attachment holes and said corresponding through holes of the respective other metallic plates and tip ends of said tubular projections being enlargeable so as to firmly attach said pair of metallic plates to said circuit board.

A semiconductor module comprising:

• a circuit board provided with a plurality of attachment holes;
• semiconductor elements or semiconductor devices mounted on said circuit board;
• a pair of metallic plates between which said circuit board is disposed in such a manner that spaces are defined between said circuit board and said pair of metallic plates for accommodating said semiconductor elements or semiconductor devices, when said pair of metallic plates are attached to said circuit board;
• one of said metallic plates provided at positions corresponding to said attachment holes with through holes;
• the other metallic plate provided at positions corresponding to said attachment holes with tubular projections having a length larger than a sum of a thickness of said circuit board and a thickness of said one metallic plate;
• and
• said tubular projections being inserted into and extending through said attachment holes and said through holes and tip ends of said tubular projections being enlarged to firmly attach said pair of metallic plates to said circuit board.

A semiconductor module comprising:

• a circuit board provided with a plurality of attachment holes;
• semiconductor elements or semiconductor devices mounted on said circuit board;
• a pair of symmetrical metallic plates between which a circuit board, having at least a pair of attachment holes, is disposed in such a manner that spaces are defined between said circuit board and said pair of metallic plates for accommodating semiconductor elements or semiconductor devices mounted on said circuit board, when said pair of metallic plates are attached to said circuit board;
• each of said metallic plates provided, at a position corresponding to one of said attachment holes, with a through hole and at a position, corresponding to the other attachment hole, with a tubular projection having a length larger than a sum of a thickness of said circuit board and a thickness of the metallic plate;
• said tubular projections of the respective metallic plates capable of insertable into said corresponding attachment holes and said corresponding through holes of the respective other metallic plate and tip ends of said tubular projections capable of being enlarged so as to firmly attach said pair of metallic plates to said circuit board.