Heat transfer module for ultra high density and silicon on silicon packaging applications

#1. Field of the Invention

#This invention relates to a heat transfer technology for use in conjunction with high packaging density semiconductor devices to rapidly remove heat from the semiconductor devices.

#2. Brief Description of the Prior Art

#FIG. 1 is a top view of an electronic circuit with metal matrix in accordance with the present invention;

#FIG. 2 is a cross-sectional side view of a portion of the embodiment of FIG. 1 the metal matrix in exploded view;

#FIG. 3 is a cross-sectional view of the embodiment of FIG. 1 with a heat dissipating housing and sponge material therewithin;

#Referring first to FIG. 1, there is shown a typical electronic circuit 1 having, for example, a plurality of memory chips 3 which have a high power requirement and dissipate a large amount of heat (e.g., 10 watts per square inch), a distributing unit 5 which may have a relatively low power requirement and dissipates a relatively small amount of heat (e.g., 1 to 2 watts per square inch), a CPU chip 7 which has a high power requirement and dissipates a relative large amount of heat (e.g., 20 watts per square inch) and a further chip 9 which may have a moderate power requirement and dissipate a moderate amount of heat (about 5 watts per square inch). The chips are disposed on a substrate 11 which can be formed of, for example, monocrystalline silicon and which has interconnecting wiring thereon (not shown) of standard design to interconnect the several chips thereon as well as to extend to contacts (not shown) for communication external to the circuit 1. Silicon is preferred because it is readily available and because it can also be used to form electronic components thereon. The substrate 11 is disposed on a metal matrix composite plate 13 which will be described in more detail hereinbelow which acts to distribute the heat produced more evenly along the substrate 11 as well as to aid in the removal of heat from the device 1.

#Referring to FIG. 2, there is shown a cross sectional view of a portion of the circuit of FIG. 1 which includes the metal matrix composite plate 13 on which is disposed the substrate 11 with chips 3 and 9 thereon. The plate 13 is a layer of heat conducting metal, preferably copper or aluminum, which has a matrix of carbon fibers 15 in a plurality of layers, each layer having a plurality of such fibers in rows, each layer being orthogonal to the layers above and below. The carbon fibers of adjacent rows preferably do not touch each other. It can be seen that heat from the chips 3 and 9 of FIG. 2 will be carried downward through the substrate 11 to the metal matrix 13. The heat will travel in the metal matrix to the carbon fibers 15 which have greater thermal conductivity than the metal of the matrix and cause the heat to travel away from their source in all directions including downward.

#It is further now necessary to dissipate the heat travelling through the metal matrix 13 and away from the substrate 11. This is generally accomplished by use of air, water, fluorocarbon and other well known heat conductive materials which pass over one or more surfaces of the metal matrix 13 and a heat transfer device attached thereto.