Method of and apparatus for forming a unitary heat sink body

Apparatus for forming a unitary heat sink body for use in removal of heat from a heat generating electronic device, said heat sink body having a generally rectangular base and a plurality of spaced parallel fins extending from said base, said apparatus comprising:

• (a) supporting apparatus for supporting a plurality of generally rectangular flat plates of a heat conductive and heat dissipating material in a fixed position so that the plates are spaced and parallel and each plate has a freely extending end;
• (b) a die cast mold which has a cavity and a generally rectangular opening to the cavity, said die cast mold being movable toward and away from the free ends of said plates between an inactive position in which the mold is substantially spaced from the plates and an active position in which the free ends of the plates extend into the cavity of the mold, said die cast mold having an aperture for enabling molten metal to be injected into said cavity;
• and
• (c) sealing means for sealing the opening to said cavity around and between said plates so that when molten metal is injected into said cavity, the molten metal will enter the spaces between the free ends of the plates within the cavity for forming said base and for supporting said plates when the molten metal solidifies.

A method of forming a unitary heat sink body for use in removal of heat from a heat generating electronic device, said body having a base and a plurality of spaced fins which extend from the base, said method comprising the following steps:

• (a) providing a first die member having a first face surface which contains a cavity;
• (b) providing a second die member having a second face surface which has a socket which faces said cavity;
• (c) interleaving a plurality of spacing plates with a plurality of fin plates so that one end of each fin plate extends freely beyond the spacing plates to form a plate cartridge in which fin plates alternate with spacer plates and said fin plates are aligned in a row, said fin plates being parallel and spaced from one another;
• (d) inserting the plate cartridge within the socket so that said one end of each fin plate extends toward said cavity;
• (e) moving one of said first and second die members toward the other of said first and second die members so that said first and second face surfaces abut and said one end of each fin plate extends into said cavity;
• (f) injecting molten metal into said cavity so that said one end of each fin plates which is located within said cavity is completely surrounded by said molten metal;
• (g) allowing said molten metal to solidify to form a base for supporting said one end of said fin plates and thereby forming a unitary heat sink body having a base and projecting spaced parallel fins;
• and
• (h) removing said unitary heat sink metal body from said cavity.

An injection die apparatus for forming a unitary heat sink body for use in removal of heat from a heat generating electronic device, said heat sink body having a base and a plurality of spaced parallel fins extending from said base, said injection die comprising:

• (a) a first die member having a first face surface which contains a cavity;
• (b) a second die member having a second face surface which faces said first face surface, said second face surface having a socket which faces said cavity;
• (c) fin spacing and retaining means for maintaining a plurality of flat fin plates within said socket so that the fin plates are spaced in a row and so that each of said fin plates has a free end which extends beyond said second face surface toward said cavity;
• and
• (d) one of said first and second die members being movable toward and away from the other of said first and second die members between an open position in which said first and second face surfaces are spaced from each other and a closed position in which said first and second face surface abut, said fins being insertable within said socket when said die members are in said open position so that when said die members are in said closed position, the free end of said fin plates extend into said cavity and said cavity is sealed by said second face surface and said fin spacing and retaining means, for enabling molten metal to be injected into said cavity and so that said molten metal enters the spaces between said fin plates to form said base for supporting said fin plates when said molten metal is allowed to solidify.

Apparatus for forming a unitary heat sink body for use in removal of heat from a heat generating electronic device, said heat sink body having a generally rectangular base and a plurality of spaced parallel fins extending from said base, said apparatus comprising:

• (a) supporting apparatus for supporting a plurality of generally rectangular flat fin plates of a heat conductive and heat dissipating material in a fixed position so that the plates are parallel and spaced from one another and each fin plate has a freely extending end;
• (b) a die cast mold which has a cavity and a generally rectangular opening to the cavity which faces the free ends of said fin plates;
• (c) one of said die cast mold and said supporting apparatus being movable toward and away from the other of said die cast mold and said supporting apparatus between an inactive position in which the die cast mold is substantially spaced from said fin plates and an active position in which the fee ends of said fin plates extend into said cavity, said die cast mold having a passageway which leads to said cavity for enabling molten metal to be injected into said cavity;
• and
• (d) sealing means for sealing the opening to said cavity around and between said fin plates so that when molten metal is injected into said cavity, the molten metal will enter the spaces between the free ends of the plates within the injection cavity for forming said base and for fixing said fin plates to the base when said molten metal solidifies.