JPH04215462A - Heat sink and manufacture thereof - Google Patents

Abstract

PURPOSE:To provide a warp-free heat sink for an IC by filling a heat-radiating material of copper or copper alloy into through holes in a flat base plate made of Invar. CONSTITUTION:An Invar base 1 and a copper plate 2 are stacked, and the Invar is partially fitted into the copper plate by half-punching with punches 6, and part of copper thus enters holes 4 in a die 5. After the die and the punches are moved to the opposite sides, the punches are hit into the copper plate to make through holes 7 in the base 1, while the through holes are filled with copper as a heat radiator 8. Scraps punched out of holes 7 are removed.

Description

[Detailed description of the invention]

0001

[Field of Industrial Application] The present invention relates to a heat sink and a method for manufacturing the same, and more particularly to an IC made of silicon, for example.
The present invention relates to a heat dissipation plate used for dissipating heat generated from semiconductors such as semiconductors, and a method for manufacturing the same.

0002

[Prior Art] Conventionally, the allowable temperature of semiconductors such as ICs made of silicon is said to be limited to 150°C, and in order to prevent such semiconductors from deteriorating, they are placed on heat sinks made of copper plates. , the heat generated by the semiconductor was dissipated from the heat sink.

However, the coefficient of thermal expansion of an IC semiconductor made of silicon is 40×10-7 (at20-15
0℃), thermal conductivity 0.2cal/(cm・sec・℃
), while the coefficient of thermal expansion of copper is 170×10-7
(at20~150℃), thermal conductivity 0.94cal/
(cm・sec・℃), so distortion is likely to occur between the two, so as shown in Figure 7, IC semiconductor b is placed on a heat sink a made of a copper plate using molybdenum [with a coefficient of thermal expansion of 46 x 10-7]. at20 to 150℃), thermal conductivity 0.34cal/(cm・sec・℃)], or tungsten [thermal expansion coefficient 45×10-7(at20
~150℃), thermal conductivity 0.39cal/(cm・s
The IC semiconductor was placed through a plate-shaped intermediate member c consisting of ec .degree.

0004

However, the material of the intermediate member c interposed between the heat dissipating plate a made of a copper plate and the semiconductor c is made of molybdenum or tungsten, which poses a problem in that it is extremely expensive.

The present invention solves the above-mentioned problems and provides an inexpensive heat sink having a coefficient of thermal expansion equivalent to that of an IC semiconductor and a thermal conductivity equal to or higher than that of molybdenum or tungsten, and a method for manufacturing the same. The purpose is to provide

[0006]

[Means for Solving the Problems] The heat dissipation plate of the present invention has a heat dissipation member made of a copper material or a copper alloy material in a through hole formed in a plate-like base material made of an invar alloy in the thickness direction thereof. It is characterized by being fitted.

Another type of heat dissipation plate is a base material made of an invar alloy, with heat dissipation members made of a copper material or a copper alloy material fitted into through holes formed in the thickness direction of the plate. It is characterized in that copper plates or copper alloy plates are laminated and polymerized via the base material.

[0008] In addition, the method for manufacturing a heat sink of the present invention includes stacking a plate-shaped base material made of an invar alloy and a plate-shaped copper material or copper alloy material having the same thickness as the base material, and After half-punching the base material and the copper material or copper alloy material on the copper material or copper alloy material side, punch out the half-punctured part from the copper material or copper alloy material side to the base material side and insert it into the base material in the thickness direction. It is characterized in that a through hole is formed extending over the area, and a heat dissipating member made of a copper material or a copper alloy material is fitted into the through hole.

Another manufacturing method is to stack a plate-shaped base material made of an invar alloy and a plate-shaped copper material or copper alloy material having the same thickness as the base material, and then insert the copper material or copper alloy material from the base material side. After punching out half of the base material and copper material on the copper alloy material side, punch out the half punched portion from the copper material or copper alloy material side to the base material side to form a through hole in the base material in the thickness direction. At the same time, after fitting a heat dissipation member made of copper material or copper alloy material into the through hole,
It is characterized by laminating and polymerizing copper plates or copper alloy plates on both sides of the base material.

0010

[Operation] The heat sink having the above structure radiates heat generated from the semiconductor to the outside from the heat sink member made of copper or copper alloy material fitted into the through hole of the base material. In this case, since the heat sink has a coefficient of thermal expansion equivalent to that of the semiconductor, no distortion occurs between the semiconductor and the heat sink.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the accompanying drawings. Example 1 Figures 1 and 2 show an example of the manufacturing method of the present invention, and in the figures, 1 is made of Fe-36.5% Ni Invar alloy, for example, and has a thickness of 1.5 mm, a width of 5 cm, and a length of A 20 cm plate-shaped base material 2 indicates a plate-shaped copper (for example, pure copper) material having the same thickness and size as the base material 1. First, as shown in FIGS. 1 and 2, a heat sink material 3 is formed by overlapping a copper material 2 on a base material 1.
form. Next, a die 5 having a hole 4 with a diameter of 1 mm is set on the surface 2a of the copper material 2 of the heat sink material 3 (see FIG. 2a), and the base material 1 is placed at a position corresponding to the hole 4 of the die 5.
A punch 6 having the same diameter as the hole 4 is set on the surface 1a of the hole 4 (see Fig. 2b), and the punch 6 is used to half punch the base material 1 and the copper material 2 from the base material 1 side to the copper material 2 side. , a part of the base material 1 is press-fitted into the copper material 2, and a part of the copper material 2 is pressed into the surface 2a thereof.
After protruding into the hole 4 of the die 5 (see FIG. 2c),
The die 5 is removed from the base material 1, and the punch 6 is removed from the copper material 2. Subsequently, the die 5 is set on the surface 1a of the base material 1, and the punch 6 is set on the copper material 2 (see FIG. 2d). Next, punch the punch 6 from the copper material 2 side toward the base material 1 side, and while inserting the copper material 2 into the base material 1 (see Fig. 2e), punch the base material 1 at a predetermined position with the thickness of the base material 1. A through hole 7 is formed in the horizontal direction, a heat dissipating member 8 made of copper material is fitted into the through hole 7 (see FIG. 2f), and a scrap 9 of the base material 1 corresponding to the through hole 7 is inserted into the base material. Release outward from 1. Next, after removing the die 5 from the copper material 2 and the punch 6 from the base material 1, the copper material 2 is separated from the base material 1. Through the above steps, the surface area 100c of the base material 1 as shown in FIGS. 3 and 4 is
A heat sink 10 (area ratio of the heat sink to the surface area of the base material: 19%) was prepared in which 2,400 heat sinks 8 with a diameter of 1 mm were scattered per m2 (10 cm x 10 cm). In the present invention, half-punching refers to the extent to which no continuous through hole is created between the base material 1 and the copper material 2 when punching from the base material 1 toward the copper material 2 side using a die and a punch. It is shown that the base material 1 stops in the middle of the copper material 2 by punching to about 1/2 of the thickness of the material, and that the copper material does not fall off. When the thermal expansion coefficient and thermal conductivity of the heat sink 10 thus produced were investigated, the thermal expansion coefficient was 18 x 10-7 (at20~
150℃), thermal conductivity is 0.3cal/(cm・se
c・℃). Also, the area of the heat sink 10 is 100 cm.
The price per 2 was 1/2 that of molybdenum of the same size, and 1/3 of that of tungsten of the same size. Note that when the produced heat sink 10 is subjected to a diffusion annealing treatment in an oxygen-free atmosphere, the heat sink members fitted into the through holes of the base material are more firmly bonded to the base material. Example 2 The material of the heat dissipation member fitted into the through hole formed in the base material was a copper alloy (for example, Cu-0.15%Sn-0) instead of copper material.
．． A heat sink was prepared in the same manner as in Example 1 except that the heat sink was made of 01% P) material, and the thermal expansion coefficient and thermal conductivity of the prepared heat sink were examined.The coefficient of thermal expansion was 16 x 10.
-7 (at20~150℃), thermal conductivity is 0.25
cal/(cm·sec·°C). Embodiment 3 FIG. 5 shows an embodiment of another manufacturing method of the present invention. In the figure, 1 is made of Fe-36.5% Ni Invar alloy, for example, and has a length of 1.5 mm in thickness and 5 cm in width. The base material 2 in the form of a long plate is a long plate-like copper (for example, pure copper) material having the same thickness and width as the base material 1. First, as shown in FIG.
A long base material 1 wound around a roller 12 and a long copper material 2 wound around a roller 12 are respectively fed out, and the base material and the copper material are overlapped between a pair of overlapping rollers 13 to form a long heat sink. Form material 3. Next, a die 5 with a hole 4 having a diameter of 1 mm is formed on the surface 2a of the copper material 2 of the heat sink material 3 (corresponding to FIG. 2a).
and set a punch 6 with the same diameter as the hole 4 on the surface 1a of the base material 1 at a position corresponding to the position of the hole 4 of the die 5 (Fig.
b), half-punch the base material 1 and the copper material 2 from the base material 1 side toward the copper 2 side, and press-fit a part of the base material 1 into the copper material 2. A part of the copper material 2 on its surface 2
It was made to protrude into the hole 4 of the die 5 from a (corresponding to Fig. 2c)
Thereafter, the die 5 is removed from the base material 1, and the punch 6 is removed from the copper material 2. Subsequently, the die 5 is set on the surface 1a of the base material 1, and the punch 6 is set on the surface of the copper material 2 (corresponding to FIG. 2d). Next, punch the punch 6 from the copper material 2 side toward the base material 1 side, and insert the copper material 2 into the base material 1 (corresponding to FIG. A through hole 7 is formed in the horizontal direction, a heat dissipating member 8 made of a copper material is fitted into the through hole 7 (corresponding to FIG. 2f), and a scrap 9 of the base material 1 corresponding to the through hole 7 is placed as a base. It is released outward from material 1. The steps up to this point are the same as those shown in FIGS. 2a to 2f in the first embodiment. Furthermore, the term "half punching" used herein is the same as that described in the first embodiment. Next, after removing the die 5 from the copper material 2 and the punch 6 from the base material 1, the copper material 2 is separated from the base material 1 and wound around the roller 14 to form a long substrate P on which a heat dissipation member is fitted. are created in a continuous manner. Subsequently, the long substrate P and the long 0.25 mm thick copper (for example, pure copper) plate 16 wound around the roller 15 are supplied between the pair of overlapping rollers 17 to form the long substrate. After laminating and polymerizing the copper plates 16 on both surfaces of P, the copper plates 16 are wound up on a take-up roller 18 and then cut into a predetermined size, or immediately cut into a predetermined size without being wound on a roller. Through the above steps, the surface area of the base material 1 as shown in FIG.
Per cm2 (10cm x 10cm), diameter 1.2m
A heat sink 19 (area ratio of the heat sink to the surface area of the base material: 20%) was prepared in which 1,800 heat sink members 8 of m were scattered and copper plates 16 were laminated and polymerized on both sides with the base material 1 interposed therebetween. Then, when the thermal expansion coefficient and thermal conductivity of the created three-layered heat dissipation plate 19 were examined, the thermal expansion coefficient was 38×10
-7 (at20~150℃), thermal conductivity is 0.76
cal/(cm·sec·°C). The price per 100 cm2 of area of the heat sink 19 was 60% that of molybdenum with the same size, and 1/2 that of tungsten with the same size. Incidentally, if the substrate P and the copper plate 16 are subjected to a degreasing process and a wire brushing process, respectively, before the substrate P and the copper plate 16 are laminated and polymerized between the polymerization rollers 17, the substrate P and the copper plate 1
The surface of 6 becomes clean and lamination polymerization can be carried out reliably. Furthermore, when the produced heat sink 19 is subjected to diffusion annealing treatment in an oxygen-free atmosphere, the heat sink members fitted into the through holes of the base material are more firmly bonded to the base material. Example 4 The material to be fitted into the through hole formed in the base material 1 was a copper alloy (for example, Cu-0.15%Sn-0.01%) instead of copper material.
P) material, and the material laminated to the base material is a copper alloy (e.g. Cu-0.15%Sn-0.01%P) instead of a copper plate.
A heat sink was prepared in the same manner as in Example 3 except that it was made into a plate, and the thermal expansion coefficient and thermal conductivity of the prepared heat sink were examined.The coefficient of thermal expansion was 37 x 10-7 (at
20~150℃), thermal conductivity is 0.75cal/(c
m・sec・℃).

[0012] The size of the heat dissipation member shown in each of the above embodiments,
The shape, number, and area ratio to the surface area of the base material are not particularly limited to these in the present invention, and may be appropriately set according to the size and shape of the IC semiconductor, the size and thickness of the base material, etc. . For example, the area ratio of the heat dissipation member (relative to the surface area of the base material) may be about 15 to 25%, and the area of each heat dissipation member should be adjusted according to the size and shape of the semiconductor placed on it. , about 0.5 to 2.0 mm2. Furthermore, the number of layers of copper plates or copper alloy plates laminated via the base material is not limited to the above-mentioned embodiments, and may vary depending on the size and shape of the IC semiconductor, the coefficient of thermal expansion of the base material, and the thermal conductivity. etc. may be set appropriately. By the way, base material 1
When the thickness of the heat dissipation member 8 is 1.5 mm and the area ratio of the heat dissipation member 8 is 15%, the coefficient of thermal expansion and thermal conductivity of the heat dissipation plate when the area ratio is 25% are investigated. In Example 1, the area ratio is 15%. At 15%, the coefficient of thermal expansion is 14 x 10-7 (at20
~150℃), thermal conductivity is 0.24cal/(cm・
sec ・℃), in Example 1, when the area ratio is 25%, the thermal expansion coefficient is 23 × 10-7 (at 20 to 150℃), and the thermal conductivity is 0.46 cal/(cm・sec ・℃), and the In Example 3, when the area ratio is 15%, the coefficient of thermal expansion is 28 x 10-7 (at 20 to 150°C), and the thermal conductivity is 0.67 cal/(cm・sec・°C), Example 3
When the area ratio is 25%, the coefficient of thermal expansion is 45 x 10-7
(at20~150℃), thermal conductivity is 0.8 cal/
(cm・sec・℃). In this way, in the present invention, the thickness of the base material 1 and the dimensions, shape, and number of through holes 6 formed across the thickness direction, or the thickness of the copper plate or stainless steel plate laminated and polymerized on the base material 1 can be adjusted. By adjusting the coefficient of thermal expansion and thermal conductivity, it is possible to arbitrarily set the coefficient of thermal expansion and thermal conductivity. In addition, in producing the heat sink in the present invention, as shown in Example 1, the heat sink is produced in a batch manner in a single length state,
Alternatively, as shown in Example 3, it may be carried out continuously in a long state.

[0013]

[Effects of the Invention] When using the heat sink of the present invention, the heat dissipating member fitted into the through hole formed in the base material in the thickness direction is in contact with the base material with their newly formed surfaces, so that both Since it is firmly bonded and does not come into contact with air, it will not fall off during use or its thermal conductivity will decrease, so it has a coefficient of thermal expansion equivalent to that of IC semiconductors and excellent heat dissipation. , heat generated by the IC semiconductor can be quickly dissipated without causing distortion between the IC semiconductor and the heat sink,
It also has the advantage of being easy to handle. In addition, a heat sink with a multilayer structure in which copper plates or copper alloy plates are laminated and polymerized via a base material has the effect of further improving thermal conductivity due to the synergistic effect of the high thermal conductivity of the copper plates or copper alloy plates. . Furthermore, when using the manufacturing method of the present invention, the coefficient of thermal expansion and thermal conductivity can be set arbitrarily, so it is easy to produce a heat sink that has a coefficient of thermal expansion equivalent to that of an IC semiconductor, has excellent heat dissipation properties, and is easy to handle. It has the effect of being able to be manufactured.

[Brief explanation of the drawing]

FIG. 1 is a process diagram of the manufacturing method of the present invention.

FIG. 2 is an explanatory diagram of a state in which a heat dissipation member is fitted to a base material of the present invention.

FIG. 3 is a perspective view of a heat sink produced by the method of the present invention.

FIG. 4 is an enlarged sectional view taken along the line AA in FIG. 3;

FIG. 5 is a process diagram of another manufacturing method of the present invention.

FIG. 6 is an enlarged cross-sectional view similar to FIG. 3 of a heat sink produced by another manufacturing method of the present invention.

FIG. 7 is an explanatory diagram using a conventional heat sink.

[Explanation of symbols]

1 Base material 6 Through hole 8 Heat dissipation member 10,19 Heat sink

Claims (4)

[Claims] 1. A heat dissipating plate characterized in that a heat dissipating member made of a copper material or a copper alloy material is fitted into a through hole formed in a plate-shaped base material made of an invar alloy in the thickness direction thereof. 2. A copper plate is attached to both sides of a base material made of an invar alloy, in which a heat dissipating member made of a copper material or a copper alloy material is fitted into a through hole formed in the thickness direction of the plate. Or a heat sink characterized by laminating and polymerizing copper alloy plates. Claim 3: A plate-shaped base material made of an Invar alloy;
Layer plate-shaped copper or copper alloy materials of the same thickness as the base material, half-punch the base material and the copper material or copper alloy material from the base material side to the copper material or copper alloy material side, and then half-punch the base material and the copper material or copper alloy material. A through hole is formed in the base material by punching from the copper material or copper alloy material side to the base material side, and a heat dissipation member made of the copper material or copper alloy material is fitted into the through hole. A method for manufacturing a heat sink, characterized by: Claim 4: A plate-shaped base material made of an Invar alloy;
Layer plate-shaped copper or copper alloy materials of the same thickness as the base material, half-punch the base material and the copper material or copper alloy material from the base material side to the copper material or copper alloy material side, and then half-punch the base material and the copper material or copper alloy material. A through hole is formed in the base material by punching from the copper material or copper alloy material side to the base material side, and a heat dissipation member made of the copper material or copper alloy material is fitted into the through hole. After that, a method for producing a heat sink is characterized in that copper plates or copper alloy plates are laminated and polymerized on both sides of the base material.