Tokyo Tungsten Co., Ltd.

A.l.m.t. Corporation

Hidetoshi Maesato

Tadashi Arikawa

Mitsuo Osada

Norio Hirayama

Akira Ichida

Kiyoshi Asai

Yoshinari Amano

Kenji Sakimae

Hidefumi Hayashi

Hiroshi Murai

A material for a semiconductor-mounting heat dissipation substrate comprises a copper-molybdenum rolled composite obtained by impregnating melted copper into a void between powder particles of a molybdenum powder compact to obtain a composite of molybdenum and copper and then rolling the composite. In a final rolling direction of a plate material, the coefficient of linear expansion is 8.3&#xd7;10/K at 30&#x2013;800&#xb0; C. The material for a semiconductor-mounting heat dissipation substrate is superior in thermal conductivity to a CMC clad material and easy in machining by a punch press. The substrate material is used as a heat dissipation substrate () of a ceramic package ().

Method of producing a heat dissipation substrate of molybdenum powder impregnated with copper with rolling in primary and secondary directions

A package to be mounted with semiconductor chips has a heat-radiating substrate having a thickness of smaller than 0.4 mm of a Cu&#x2014;Mo composite as prepared by impregnating from 30 to 40% by mass of copper (Cu) melt into a green compact of molybdenum. The heat-radiating substrate is produced by preparing an Mo green compact through isostatic molding, mounting Cu on the Mo green compact, heating it to thereby impregnate copper into the Mo green compact to give a Cu&#x2014;Mo composite, and rolling the Cu&#x2014;Mo composite into a sheet substrate. In the isostatic molding process, at least two or more platesandare disposed adjacent to the inner surface of a side wall as divided into at least two portions, Mo powder is filled into the space as formed by those platesandwith covering the Mo powder compact with a flexible cover, such as a rubber mediumor the like, to prepare a composite, then the resulting composite is put into a pressure tank, an external isostatic pressure is applied thereto against the flexible cover, and the plates are slid via the cover along the side wall thereby compressing the composite between the thus-slid plates into an Mo green compact.

Semiconductor package and method for producing heat-radiating substrate for it

A package to be mounted with semiconductor chips has a heat-radiating substrate having a thickness of smaller than 0.4 mm of a Cu&mdash;Mo composite as prepared by impregnating from 30 to 40% by mass of copper (Cu) melt into a green compact of molybdenum. The heat-radiating substrate is produced by preparing an Mo green compact through isostatic molding, mounting Cu on the Mo green compact, heating it to thereby impregnate copper into the Mo green compact to give a Cu&mdash;Mo composite, and rolling the Cu&mdash;Mo composite into a sheet substrate. In the isostatic molding process, at least two or more plates. and are disposed adjacent to the inner surface of a side wall as divided into at least two portions, Mo powder is filled into the space as formed by those plates and with covering the Mo powder compact with a flexible cover, such as a rubber medium or the like, to prepare a composite, then the resulting composite is put into a pressure tank, an external isostatic pressure is applied thereto against the flexible cover, and the plates are slid via the cover along the side wall thereby compressing the composite between the thus-slid plates into an Mo green compact.

A heat sink substrate comprises a Cu&mdash;Mo composite substrate composed of a molybdenum (Mo) green compact with which Copper (Cu) of 20-60 wt % is impregnated. It is preferable that the heat sink substrate is a rolled plate obtained by repeatedly warm rolling or cold rolling the Cu&mdash;Mo composite substrate and that the rolled plate does not include any fine void and unevenly impregnated copper, that is, copper and molybdenum are uniformly distributed therein.

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Sakata, Japan

Hidetoshi Maesato