JP2003188324A - Heat dissipating base material, method of manufacturing the same, and semiconductor device containing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat dissipating base material which is more superior in thermal conductivity than its mother material. <P>SOLUTION: This heat dissipating base material is mounted with a semiconductor device to cool it down. The dissipating base material is provided with a first and a second surface which are nearly parallel with each other. The dissipating base material is composed of a mother material 1 where a semiconductor device is mounted on the first surface and rods 2 which have higher thermal conductivity than the mother material 1 and are implanted upright and fixed on the second surface of the mother material 1. The rods 2 are partially exposed to the air. The base material 1 is formed of copper or copper alloy. The rods 2 are formed of carbon fiber-reinforced carbon composite material, carbon-based metal composite material, carbon fiber/metal composite material containing carbon fiber-reinforced metal, or high thermal conductivity metal material. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat dissipating base material and a method for manufacturing the same, and more particularly to a heat dissipating base material having good heat conduction characteristics exceeding those of a base material and a method for manufacturing the same.

[0002]

2. Description of the Related Art FIG. 10 is a cross-sectional view of a semiconductor device described in Japanese Unexamined Patent Publication No. 10-150124, which is generally denoted by 500. The semiconductor device 500 includes a heat dissipation base 510 having a metal layer 520 and a composite layer 530. The metal layer 520 is composed only of a metal base material (metal base material) 501 having high thermal conductivity. On the other hand, the composite layer 530 is composed of a metal base material 501 having high thermal conductivity and a fibrous or particulate dispersion material 502 having low thermal expansion dispersed in the metal base material 501. The metal layer 520 and the composite layer 530 both include the metal base material 501, and both have a continuous structure.

A metal coating 503 is provided on the composite layer 530. A low expansion substrate 505 on which a heat generating semiconductor device 506 is mounted is fixed on the metal film 503 via a solder layer 504. As a result, the heat generated in the semiconductor device 506 is applied to the solder layer 504 and the metal film 5.
It is transmitted to the composite layer 530 and the metal layer 520 via 03 and is radiated to the outside.

On the other hand, as a method for producing a composite material of copper and carbon fibers using a sintering method, Japanese Patent Laid-Open No. 143455/1982 discloses that metal powder having a melting point lower than that of the base metal powder is pressed in a heating furnace. A method of performing main sintering after the addition of calcination is disclosed. Further, in Japanese Patent Laid-Open No. 57-185942,
A method of sintering copper-plated carbon fibers is disclosed.

[0005]

However, the heat radiation substrate 510 has a structure in which the fibrous or particulate dispersion material 502 is dispersed in a part of the metal base material 501. Therefore, even when a fiber having high thermal conductivity is used as the dispersion material 502, the metal base material 50 is used as a whole in the heat dissipation base 510.
The characteristics of No. 1 became dominant, and the heat conduction characteristics exceeding the characteristics of the metal base material 501 could not be obtained. Therefore, there is a limit to suppressing the temperature rise of the semiconductor device 506, and especially when using a semiconductor device such as a power module that generates a large amount of heat, a heat dissipation base material having higher heat dissipation characteristics is required. Further, since the portion of the heat radiation fin 507 is finished by machining, the manufacturing cost is increased.

Therefore, the present invention provides a heat dissipating base material having good heat conduction characteristics exceeding the characteristics of the base material and a method for manufacturing the same.
Another object of the present invention is to provide a semiconductor device using such a heat dissipation base material.

[0007]

SUMMARY OF THE INVENTION The present invention is a heat dissipating substrate for mounting and cooling a semiconductor device, the first heat dissipating substrate being substantially parallel.
A base material having a surface and a second surface, on which the semiconductor device is mounted on the first surface, and embedded and fixed in the base material along a substantially normal direction of the second surface, A rod having a thermal conductivity higher than that of the base material, and a part of the rod is the second material of the base material.
It is a heat dissipation base material that is exposed from the surface. In the heat dissipation base material according to the present invention, by using the structure in which the tip of the rod embedded in the base material is exposed from the base material, it is possible to provide a heat dissipation base material having good heat dissipation characteristics exceeding the heat dissipation characteristics of the base material. . As a result, the thermal strain generated at the joint between the heat dissipating base material and the semiconductor device mounted on the heat dissipating base material can be mitigated, and damage to the joint portion can be prevented.

The present invention is also a heat dissipation base material characterized in that one end of the rod is projected from the second surface of the base material. Thus, by projecting one end of the rod having a higher thermal conductivity than the base material from the base material and bringing it into contact with the cooling medium, good cooling characteristics can be obtained.

Further, the present invention is also a heat dissipating base material characterized in that one end of the rod has a flat end surface which is included in substantially the same plane as the second surface of the base material. In this way, by disposing one end of the rod having a higher thermal conductivity than the base material on substantially the same plane as the second surface of the base material, the heat radiation fins arranged on the second surface are brought into contact with each other, which is favorable. Heat dissipation characteristics can be realized.

The base material is made of copper or a copper alloy, and the rod is made of carbon fiber-reinforced carbon composite material, carbon-based metal composite material, carbon fiber / metal composite material containing carbon fiber-reinforced metal, or high thermal conductivity. It is made of at least one of metallic materials.

The base material is Cr, Mo, W, C, Si.
At least 1 selected from the group consisting of C and AlN
It is preferable to use a copper alloy containing 5 to 40% by volume of one additive component. By mixing such an amount of fine powder, the thermal expansion coefficient can be lowered while maintaining the thermal conductivity of the heat dissipation base material high.

The base material is preferably made of a copper alloy containing the above-mentioned additional components dispersed as fine powder having a particle size of 100 μm or less. By setting the particle size of the fine powder to 100 μm or less, it is possible to obtain a copper alloy having a uniform composition.

The rod may be covered with a coating layer containing a component selected from the group consisting of Cu, Ni, Au, W and SiC as a main component. By coating the rod, the adhesion between the base material and the rod is improved, and moisture absorption of the rod can be prevented.

The base material and the rod exposed from the base material are covered with a coating layer containing a component selected from the group consisting of Cu, Ni, Au, W, and SiC as a main component. May be.

The rods may be composed of a plurality of rods made of different materials.

The present invention also provides a method of manufacturing a heat dissipation base material including a base material and a rod having one end exposed from the base material,
A rod preparing step of preparing a rod made of at least one of a carbon fiber / metal composite material and a high thermal conductive metal material; and an arranging step of arranging the rod in a mold.
The step of filling the molding die with a powder containing copper as a main component and filling one end of the rod with 0.1 to 5 to
a step of pressurizing at a pressure of nf / cm ² to form a green compact in which one end of the rod is embedded, and the green compact to which the rod is fixed in a non-oxidizing atmosphere at a temperature of 700 to 1200 ° C. And a step of heating the green compact to sinter the green compact to form a base material. By using such a method for manufacturing a heat dissipation base material, it is possible to manufacture a heat dissipation base material having high heat dissipation characteristics in a simple process. In particular,
By pressurizing the powder with such a pressure, it is possible to obtain a predetermined powder compact without damaging the rod. Further, by sintering at such a temperature, it is possible to obtain a base material without deformation while preventing the remaining pores.

The arranging step is preferably a step in which a supporting jig is provided in the molding die and the plurality of rods are supported by the supporting jig so as to be substantially parallel to each other. This is to keep the plurality of rods substantially parallel.

The present invention also provides a method of manufacturing a heat dissipation substrate including a base material and a rod having one end exposed from the base material,
A rod preparation step of preparing a rod made of at least one of a carbon fiber / metal composite material and a high thermal conductive metal material, and 0.1 to 8 tonf of a powder containing copper as a main component.
/ Cm ² pressure to form a green compact,
A step of forming a hole in the green compact; a step of inserting the rod into the hole to expose one end of the rod from the green compact; and a step of inserting the rod into which the green compact is inserted. And a step of heating at a temperature of 700 to 1200 ° C. in a non-oxidizing atmosphere to sinter the green compact to form a base material. This is because the green compact is appropriately contracted in the sintering process by pressurizing with such pressure to form the green compact, and the rod and the base material are in a good joined state. Incidentally, JP-A-57-143455 and JP-A-5-143545
Japanese Patent Publication No. 7-185942 describes a method for producing a fiber-reinforced composite material. However, according to such a manufacturing method, only a composite material using short carbon fibers can be manufactured, and a heat dissipation substrate as in the present invention cannot be obtained. Further, in this manufacturing method, since sintering is performed while applying pressure, the productivity is low, and a dedicated manufacturing apparatus is required.

The present invention also provides a method of manufacturing a heat dissipation base material including a base material and a rod having one end exposed from the base material,
A rod preparation step of preparing a rod made of at least one of a carbon fiber / metal composite material and a high thermal conductive metal material, and 0.1 to 8 tonf of a powder containing copper as a main component.
/ Cm ² pressure to form a green compact,
A step of heating the green compact in a non-oxidizing atmosphere at a temperature of 400 to 700 ° C. to sinter the green compact to form a primary sintered body, and forming a hole in the primary sintered body. And the step of inserting the rod into the hole to expose one end of the rod from the primary sintered body, and the primary sintered body with the rod inserted therein in a non-oxidizing atmosphere at 700 A step of heating at a temperature of up to 1200 ° C. and further sintering the primary sintered body to form a base material.

The powder material containing copper as the main component is made of Cr, M
a fine powder containing at least one component selected from the group consisting of o, W, C, SiC, and AlN,
It is preferably made of powder mixed with copper powder in a volume percentage. By mixing such an amount of fine powder, the thermal expansion coefficient can be lowered while maintaining the thermal conductivity of the heat dissipation base material high.

The particle size of the fine powder is preferably 100 μm or less. This is because the fine powder is uniformly dispersed in the copper powder.

In the rod preparing step, Cu, Ni, A
It may include a step of covering the surface of the rod with a coating layer containing a component selected from the group consisting of u, W, and SiC as a main component. By coating the rod, the adhesion between the base material and the rod is improved, and moisture absorption of the rod can be prevented.

Further, the surfaces of the base material and the rod exposed from the base material are covered with Cu, Ni, Au, W, and SiC.
It may include a step of covering with a coating layer containing a component selected from the group consisting of as a main component.

The present invention also provides a semiconductor device including the heat dissipation base material and a semiconductor element mounted on the first surface of the heat dissipation base material, wherein the second surface of the heat dissipation base material is provided. A semiconductor device is also characterized in that the exposed rod is in contact with a cooling medium. In this way, in the heat dissipation base material, one end of the rod having higher thermal conductivity than the base material is exposed from the base material and brought into contact with the cooling medium, thereby cooling the semiconductor element mounted on the heat dissipation base material. A semiconductor device with high efficiency and high reliability can be obtained.

It is also a semiconductor device in which the heat dissipation base is attached to a heat dissipation container, and cooling water flowing in the heat dissipation container comes into contact with the rod exposed from the second surface of the heat dissipation base.

The cooling medium is the second heat-radiating base material.
It is also a semiconductor device characterized in that it is a radiation fin attached to the surface.

[0027]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiment 1. Figure 1 shows 1
It is a perspective view of the heat dissipation base material represented by 00 according to the present embodiment. Further, FIG. 2 is a cross-sectional view in the II direction of FIG. 1, and shows only a partial cross section including the four rods 2. The heat dissipation substrate 100 includes a base material 1 made of Cu and a carbon fiber reinforced carbon composite material (hereinafter, referred to as “C /
"C". And a rod 2 made of Where C
/ C is a carbon fiber reinforced carbon composite material in which carbon is used as a matrix and is reinforced with carbon fibers.

Next, the heat dissipation base material 10 according to the present embodiment.
The manufacturing method of 0 will be described. The manufacturing method includes the following steps 1 to 6.

Step 1: As shown in FIG. 3A, the rod 2 and the supporting jig 10 for supporting the rod 2 are prepared.
The C / C rod 2 has, for example, a diameter of 1 mm and a length of 5 mm.
To process. The support jig 10 is provided with a plurality of holes 11 slightly larger than the diameter of the rod 2 in the thickness direction. The rod 2 is inserted into the hole 11. By selecting the position, depth, number, and diameter of the holes 11 of the support jig 10, the position and exposed length of the rod 2 of the heat dissipation base 100 can be adjusted arbitrarily. Further, the composition, diameter, shape (cylinder, prism, etc.) of the rod can be arbitrarily selected. Next, the support jig 10 into which the rod 2 is inserted is placed in a mold (molding die) 30.

Step 2: As shown in FIG. 3B, the mold 3
The Cu powder 20 is put on the support jig 10 arranged in 0. The Cu powder 20 is added to the extent that the rod 2 does not protrude from the Cu powder 20 even if the Cu powder 20 is pressurized in the following step 3. The particle size of the Cu powder 20 is 45 μm
The following are preferred.

Step 3: As shown in FIG. 3C, the punch rod 31 is inserted from above and the Cu powder 20 is pressure-molded. As the molding pressure, for example, 0.5 tonf / cm ² is used. By such pressure molding, the Cu powder 20 becomes the green compact 3. The molding pressure is about 0.1 to 5 tonf /
It is selected from the range of cm ² . Lower limit of molding pressure is 0.1
The reason for setting tonf / cm ² is to maintain the shape of the green compact when separating the green compact from the support jig 10 and to obtain a good sintered body within the sintering temperature range described later. This is because.
Further, the upper limit of the molding pressure is set to 5 tonf / cm ² or less in order to prevent damage to the end portion of the rod 2 protruding from the support jig 10 and cracking of the rod 2.

Step 4: As shown in FIG. 3D, the mold 3
From 0, the green compact 3 is taken out together with the support jig 10. Then, the support jig 10 and the green compact 3 are separated. Thereby, the green compact 3 including a part of the rod 2 and integrated with the rod 2 is obtained.

Step 5: As shown in FIG. 3 (e), the green compact 3 integrated with the rod 2 is placed in a sintering furnace 40 and heated. The heating condition is, for example, 10 in a hydrogen atmosphere.
1 hour at 00 ° C. In this sintering step, the green compact 3 is sintered to form the base material 1. In this sintering step, sintering may be performed in an atmosphere of argon, nitrogen, ammonia decomposition gas (mixed gas of nitrogen and hydrogen) or the like instead of the hydrogen atmosphere. Further, sintering may be performed in vacuum.

The sintering temperature is about 700 to about 1200.
It is carried out within the range of ° C. In particular, when only Cu is used as a base material, a Cu powder compact is preferably used at 700 ° C. or higher.
Temperature less than 3 ℃, more preferably 900 ℃ or more 1070 ℃
Sintering is performed at the following temperatures. The reason why the lower limit of the sintering temperature is 700 ° C. is that pores do not remain inside the sintered body, and if the temperature is lower than 700 ° C., the sintering does not proceed sufficiently, and the pores remain inside the sintered body. This is because it will end up. The upper limit of the sintering temperature is set to 1083 ° C. in order to maintain the shape without melting Cu of the base material.

On the other hand, as will be described later, fine powder (fine particles)
When a Cu alloy in which is dispersed is used as the base material, the sintering temperature is
The temperature is preferably 700 ° C or higher and 1200 ° C or lower, and more preferably 900 ° C or higher and 1080 ° C or lower (solid phase sintering region) or 1090 ° C or higher and 1150 ° C or lower (in liquid phase sintering region).
Is. The mixture in which the fine powder is dispersed can be sintered by either solid phase sintering or liquid phase sintering depending on the mixing amount and combination of the fine powder.

The lower limit of the sintering temperature is set to 700 ° C. so that pores do not remain inside the sintered body. The upper limit of the solid-phase sintering is set to 1080 ° C. because the liquid phase is not generated. Further, the lower limit of liquid phase sintering is set to 1090 ° C. in order to reliably generate the liquid phase, and the upper limit is 1200 ° C.
The reason is that the deformation or expansion of the sintered body due to melting does not occur.

Step 6: As shown in FIG. 3F, the base material 1 integrated with the rod 2 is taken out from the sintering furnace 40.
As a result, one end of the rod 2 is fixed in the base material 1, and the other end of the rod 2 protrudes in the plate thickness direction of the base material 1 to obtain the heat dissipation base material 100.

Although the case where Cu is used as the material of the base material 1 has been described here, a Cu alloy may be used for the base material 1. In this case, Cu, Cr, Mo, W, C, SiC, AlN are added to the Cu powder in the step of step 2 (FIG. 3B).
5 to 4 of fine powder (fine body) made of any one or more of
A mixed powder uniformly mixed at 0% by volume is prepared in advance,
By filling this in the mold 30, the heat dissipation base 100 having the base material 1 made of a Cu alloy can be obtained.
The shape of the fine powder (fine particles) is, for example, particles, flat particles, short fibers, or whiskers.

In this step, for example, in Cu powder,
To contain 20% by volume of Cr powder, the particle size should be 45μ.
Cu powder of m or less and Cr of the same particle size of 45 μm or less
Powder is mixed with the above powder so as to have a content rate of 20% by volume and mixed in a ball mill for about 2 hours to obtain a mixed powder. continue,
The mixed powder is filled in the mold 30 and the above steps 2 to 6 are performed. Thereby, the heat dissipation base material 100 having the base material 1 in which Cr is uniformly dispersed in Cu is obtained. A small amount of a dispersant such as liquid paraffin may be added to improve the dispersibility of the Cr powder.

Here, Cr and M added to the Cu powder
The particle size of fine powder of o, W, C, SiC, AlN is 100
μm or less. This is because, when a mixed powder with Cu powder is prepared by using fine powder having a particle size of more than 100 μm, the Cu powder and the fine particles are not separated even if the volume content of the fine powder or the particle size of the Cu powder is changed. Is separated during the mixing, and the base material 1 in which the fine particles are uniformly dispersed cannot be obtained.

Embodiment 2. FIG. 4 is a cross-sectional view of the manufacturing process of the heat dissipation substrate 100 according to the present embodiment. The finally obtained heat dissipation substrate 100 is similar to that of the first embodiment (see FIGS. 1 and 2). The manufacturing method includes the following steps 1 to 5.

Step 1: As shown in FIG. 4A, a Cu green compact 4 molded at a molding pressure of ² tonf / cm ² is prepared. The particle size of Cu is 45 μm or less. The green compact 4 has a length of 20 mm, a width of 20 mm, and a height (thickness) of 10 mm. The molding pressure of the green compact 4 is
It is selected from the range of 0.1 to 8 tonf / cm ² . This is because the compressed powder body 4 contracts in the sintering process to bond the rod 2 and the base material 1. Forming pressure is 8t
When it exceeds onf / cm ² , the shrinkage in the sintering step is small and the bonding force between the rod 2 and the base material 1 is small.

Step 2: As shown in FIG. 4B, a plurality of holes 5 are formed in the green compact 4 by machining in order to insert the rod 2. The diameter of the hole 5 is slightly larger than the diameter of the rod 2. The hole 5 is provided in the plate thickness direction. The hole 5 may be either a through hole or a non-through hole.

Step 3: As shown in FIG. 4C, the hole 5
Insert rod 2 into. The rod 2 has a diameter of 1 mm and a length of 15 mm.

Step 4: As shown in FIG. 4D, the green compact 4 into which the rod 2 is inserted is placed in a sintering furnace 40 and sintered. The sintering conditions are 1000 ° C. and 1 hour in a hydrogen atmosphere.

Step 5: As shown in FIG. 4E, the base material 1 integrated with the rod 2 is taken out from the sintering furnace 40.
As a result, one end of the rod 2 is fixed in the base material 1, and the other end of the rod 2 protrudes in the plate thickness direction of the base material 1 to obtain the heat dissipation base material 100.

Embodiment 3. FIG. 5 is a cross-sectional view of the manufacturing process of the heat dissipation substrate 100 according to the present embodiment. The finally obtained heat dissipation substrate 100 is similar to that of the first embodiment (see FIGS. 1 and 2). The manufacturing method includes the following steps 1 to 7.

Step 1: As shown in FIG. 5A, a Cu green compact 4 molded at a molding pressure of ² tonf / cm ² is prepared. The particle size of Cu is 45 μm or less. The green compact 4 has a length of 20 mm, a width of 20 mm, and a height (thickness) of 10 mm. The molding pressure of the green compact 4 is selected from the range of 0.1 to 8 tonf / cm ² as in the second embodiment.

Step 2: As shown in FIG. 5B, the green compact 4 is placed in a sintering furnace 40 and sintered. The sintering conditions are 500 ° C. and 1 hour in a hydrogen atmosphere.

Step 3: As shown in FIG. 5C, in the sintering step (step 2), the primary sintered body 6 is obtained.

Step 4: As shown in FIG. 5D, in order to insert the rod 2 into the primary sintered body 6, a plurality of holes 5 are formed by machining. The diameter of the hole 5 is slightly larger than the diameter of the rod 2. The hole 5 is provided in the plate thickness direction. The hole 5 may be either a through hole or a non-through hole.

Step 3: As shown in FIG. 5E, the rod 2 is inserted into the hole 5 provided in the primary sintered body 6. Rod 2
Has a diameter of 1 mm and a length of 15 mm.

Step 4: As shown in FIG. 5 (f), the primary sintered body 6 with the rod 2 inserted therein is again placed in the sintering furnace 40 and sintered. The sintering condition is 1000 in a hydrogen atmosphere.
C for 1 hour.

Step 5: As shown in FIG. 5G, the base material 1 integrated with the rod 2 is taken out from the sintering furnace 40.
As a result, one end of the rod 2 is fixed in the base material 1, and the other end of the rod 2 protrudes in the plate thickness direction of the base material 1 to obtain the heat dissipation base material 100.

Fourth Embodiment Although the first, second, and third embodiments have described the case where the carbon fiber-reinforced carbon composite material (C / C) is used as the material of the rod 2, the material of the rod 2 is C instead of C / C. A composite material such as / CM or CFRM can also be used. The material of the rod 2 is a high thermal conductive metal material mainly containing Cu, Ag or Au, or a composite material of such a high thermal conductive metal and C / C, C / C-M or CFRM (carbon fiber). / Metal composite material) can also be used. Here, C / C-M refers to a carbon-based metal composite material in which C / C is impregnated with a metal or the like. CFRM refers to a carbon fiber reinforced metal material in which metal and carbon fiber are combined.

FIG. 6 is a cross-sectional view of the heat dissipation base material according to the present embodiment, which is generally indicated by 200. Heat dissipation base material 20
0 is the base material 1 and the rod 7 whose one end is embedded in the base material 1,
8 and. The base material 1 is Cu, or Cu, Cr, Mo,
It is made of a Cu alloy to which one or more elements of W, C, SiC and AlN are added. On the other hand, the rod 7 is made of Cu, A
The rod 8 is made of CFRM (carbon fiber / metal composite material).

FIG. 7 is a cross-sectional view of another heat dissipating base material according to the present embodiment, which is generally represented by 300. The heat dissipation substrate 200 includes a base material 1 and a rod 2 whose one end is embedded in the base material 1 and whose surface is coated with a coating layer 9. Base material 1 is C
It consists of a Cu alloy in which any one or more elements of Cr, Mo, W, C, SiC and AlN are added to u or Cu. On the other hand, the rod 2 is C / C, C / C-M, or CFRM,
A high thermal conductive metal material mainly composed of Cu, Ag or Au,
Alternatively, it is made of a composite material of C / C and the like and a high thermal conductive metal.

The coating layer 9 is formed on the rod 2 by using an electroplating method, an electroless plating method, a chemical vapor deposition method, a physical vapor deposition method or the like alone or in combination. For example, as an independent method, there is an electroless plating method in which the rod 2 is immersed in a chemical reduction bath to coat Cu or Ni.
As a combination method, there is a method in which the rod 2 is coated with SiC using a chemical vapor deposition method, and then Cu is coated therewith by an electrolytic plating method.

Further, the coating layer 9 may be formed on the entire heat dissipating base material 10 in which the rod 2 is fixed to the base material 1. For example, the whole of the heat dissipating base material 100 may be subjected to an electrolytic plating method or an electroless plating method alone or in combination to form Cu,
i, Au is coated.

As described above, by forming the coating layer 9 on the rod 2, it is possible to improve the bonding force between the base material 1 and the rod 2 and prevent moisture from being absorbed into the rod.

Embodiment 5. FIG. 8 shows a semiconductor device using the heat dissipation base material 100. A semiconductor device 6 is formed on the heat dissipation base 100 composed of the base material 1 and the rod 2 by a solder material.
0 is fixed. The heat dissipation base 100 is a cooling container 50.
It is brazed to the opening provided in the. Heat dissipation container 5
Reference numeral 0 has a coolant channel 51, and a coolant inlet 52 and a coolant outlet 53 provided on both sides of the coolant channel 51. The refrigerant container 50 is made of copper, for example. Refrigerant such as cooling water entering from the refrigerant inlet 52 passes through the refrigerant passage 51 and is discharged from the refrigerant outlet 53. The semiconductor device 60 has a structure in which a semiconductor chip is mounted on an insulating plate (not shown).

By using such a heat dissipation container 50, the rod 2 of the heat dissipation base material 100 is brought into contact with the cooling medium and directly cooled. In the heat dissipating base material 100, the base material 1 is replaced by the rod 2
Since this is made of a material having higher thermal conductivity, the cooling efficiency of the semiconductor device 60 can be made higher than before. That is, in the heat dissipation base material 100, it is possible to obtain good heat conduction characteristics exceeding the characteristics of the material of the base material 1. Note that instead of the heat dissipation base material 100, the heat dissipation base material shown in the above-described second to fourth embodiments may be used. In this case as well, it is possible to obtain good heat conduction characteristics that exceed the characteristics of the material of the base material 1.

Sixth Embodiment FIG. 9 shows a semiconductor device using the heat dissipation base material according to the present embodiment, which is generally represented by 400. Although the heat dissipation base material 400 includes the base material 1 and the rod 2, the end portion of the rod 2 does not protrude from the bottom surface of the base material 1. The end of the rod 2 is exposed on the bottom surface of the base material 1. Other configurations and materials are the same as those of the heat dissipation base material 100.
The semiconductor device 60 is fixed on the heat dissipation base material 400 with a solder material. A cap 70 is provided on the heat dissipation base 400 so as to cover the semiconductor device 60. The semiconductor package 90 is formed by these.

A heat radiation fin 80 made of copper or the like is fixed to the bottom surface of the heat radiation substrate 400 of the semiconductor package 90. By bringing the heat radiation fins 80 into contact with the bottom surface of the heat radiation substrate 400, the rod 2 exposed on the bottom surface of the heat radiation substrate 400 comes into contact with the heat radiation fins 80. Thereby, the heat generated in the semiconductor device 60 is efficiently transmitted to the heat radiation fins 80 via the rod 2.

As described above, the heat dissipation substrate 400 according to the present embodiment can be fixed to the heat dissipation fin 80, and can be used for an air-cooling type semiconductor package.

Embodiment 7. Table 1 shows the evaluation results of the heat dissipation characteristics when the heat dissipation substrate according to the present invention is used. Table 1
As shown in FIG. 5, the invention examples (No. 1 to 16) and the comparative examples (21 to 23) were evaluated for thermal cycle characteristics and temperature of the semiconductor device. The cooling container 50 shown in Embodiment 5 was used for the evaluation (FIG. 8). The base material 1 of the heat dissipation substrate had a length of 20 mm, a width of 20 mm, and a thickness of 5 mm. The length of the exposed rod 2 is 5 mm from the end surface of the base material.
The surface of the rod 2 was coated with Cu. The appearance of the heat dissipating base material including the base material 1 and the rod 2 was substantially the same in all the invention examples and the comparative examples. In the evaluation of the heat dissipation base material, the heat dissipation base material was incorporated in the cooling container 50 of FIG. 8, and cooling water having a temperature of 60 ° C. and a flow rate of 5 l / min was used as a cooling medium. The cooling water was brought into direct contact with the end surface of the heat dissipation substrate and the exposed rod. The thickness of the refrigerant container 50 is 1
It is 0 mm.

The temperature of the semiconductor device was measured by applying a load so that the heat generation amount of the semiconductor device 60 was 30 W, and measuring the temperature of the semiconductor device at this time. In addition, the thermal cycle characteristics are obtained by observing the bonding state between the heat dissipation base material and the semiconductor device by applying a heat cycle of -50 ° C to + 150 ° C 150 times in a state where the semiconductor device is soldered on the heat dissipation base material. Evaluated.

In the comparative examples (Nos. 21 to 23), the heat dissipation plate having the same shape as the above-mentioned base material was formed of Cu or Al. N
o. In Nos. 21 and 23, pin-shaped fins were formed on the heat dissipation plate by machining.

The appearance of the heat dissipating base material composed of the base material 1 and the rod 2 is substantially the same in all the invention examples and comparative examples (N
o. No. 23 has no pin fin), and the cooling conditions were the same.

[0070]

[Table 1]

No. 1-3, the base material 1 is Cu or Cu
The rod 2 is made of alloy and the carbon fiber / metal composite material (C
/ C, C / C-M, CFRM). The carbon fibers contained in the rod 2 are oriented in one direction so as to be horizontal with the length direction of the rod 2. Example No.
In Nos. 1 to 3 of the comparative example, the semiconductor device temperature was 90 ° C. or lower. It can be seen that the semiconductor device temperature can be suppressed lower than those of Nos. 21 and 22.

No. 4-9, the base material 1 is C in Cu
5-40 fine powders of r, Mo, W, C, SiC, AlN
This is a case where the rod 2 is made of an alloy added with vol% and the rod 2 is made of C / C. Compared with the comparative examples, the semiconductor device temperature is as low as 95 ° C. or less, and the rise of the semiconductor device temperature is suppressed. The coefficient of thermal expansion is 11 to 16 × 10.
^-6 / ° C, which is smaller than that of the comparative example. Further, according to the result of the heat cycle test, the heat cycle characteristic is improved because the heat distortion of the joint portion between the semiconductor device and the heat radiation base material is suppressed while suppressing the rise of the temperature of the semiconductor device.

No. 10 is a case where the base material 1 is made of an alloy in which two kinds of fine powders of C and SiC are added to Cu, and the rod 2 is made of C / C. Similarly, the temperature rise of the semiconductor device can be suppressed, the coefficient of thermal expansion is small, and the thermal cycle characteristics are improved.

No. 11 is a case where the base material 1 is made of Cu and the rod 2 uses Ag and C / C in combination. Also,
No. 12, the base material 1 is made of Cu and the rod 2 is made of Cu.
And C / C are used together. In any case, the temperature of the semiconductor device can be set to 90 ° C. or lower while maintaining good heat cycle characteristics, and the heat dissipation characteristics are improved.

No. 13 is C for both the base material 1 and the rod 2.
It consists of u. The semiconductor device temperature shows the same characteristics as those produced by the machining of the comparative example (No. 21). From this, by using the manufacturing method according to the present invention, it is possible to obtain a heat dissipation substrate having the same effect without forming pin fins by complicated machining. In addition, here, the case where the rod 2 is exposed by 5 mm from the end face of the base material is shown.
The longer the exposed length of the, the more the heat dissipation characteristics improve in proportion to the length.

No. 14 is a case where the heat dissipation base material is manufactured by the manufacturing method according to the second embodiment. In addition, No. 1
5 is a case where the heat dissipation base material is manufactured by the manufacturing method according to the third embodiment. No. 1, No. 14, No. When 15 is compared, almost the same heat dissipation performance is obtained, the thermal cycle characteristics are improved, and the rise of the semiconductor device temperature is suppressed as compared with the comparative example.

[0077]

As is apparent from the above description, in the heat dissipation base material according to the present invention, the tip of the rod having a higher thermal conductivity than the base material is exposed from the base material, and the heat dissipation characteristics of the base material. It is possible to obtain a heat dissipation base material having excellent heat dissipation characteristics exceeding

Further, it is possible to reduce the thermal strain generated at the joint between the heat dissipating base material and the semiconductor device mounted on the heat dissipating base material, and prevent the joint portion from being damaged.

By using the method for manufacturing a heat dissipation base material according to the present invention, it is possible to manufacture a heat dissipation base material having high heat dissipation characteristics in a simple process.

[Brief description of drawings]

FIG. 1 is a perspective view of a heat dissipation substrate according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view of the heat dissipation base material according to the first embodiment of the present invention.

FIG. 3 is a sectional view of a manufacturing process of the heat dissipation base material according to the first embodiment of the present invention.

FIG. 4 is a cross-sectional view of a manufacturing process of the heat dissipation base material according to the second embodiment of the present invention.

FIG. 5 is a sectional view of a manufacturing process of the heat dissipation base material according to the third embodiment of the present invention.

FIG. 6 is a sectional view of a heat dissipation base material according to a fourth embodiment of the present invention.

FIG. 7 is a cross-sectional view of another heat dissipation base material according to the fourth embodiment of the present invention.

FIG. 8 is a sectional view of a semiconductor device according to a fifth embodiment of the present invention.

FIG. 9 is a sectional view of a semiconductor device according to a sixth embodiment of the present invention.

FIG. 10 is a cross-sectional view of a conventional semiconductor device.

[Explanation of symbols]

1 base material, 2 rods, 3 and 4 green compacts, 5 holes, 1
0 support jig, 11 holes, 20 Cu powder, 30 mold, 31 punch rod, 40 sintering furnace, 100 heat dissipation base material.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Toshio Umemura             2-3 2-3 Marunouchi, Chiyoda-ku, Tokyo             Inside Ryo Electric Co., Ltd. (72) Inventor Hiroyuki Teramoto             2-3 2-3 Marunouchi, Chiyoda-ku, Tokyo             Inside Ryo Electric Co., Ltd. F-term (reference) 4K018 AA04 BA02 BA09 BB04 BC08                       BD10 CA02 CA12 DA01 DA04                       DA21 DA33 FA23 HA10 JA40                       KA32                 5F036 AA01 BA10 BA23 BB05 BD01                       BD11

Claims (20)

[Claims] 1. A heat dissipation substrate for mounting and cooling a semiconductor device, the mother substrate having a substantially parallel first surface and a second surface, and a semiconductor device mounted on the first surface. A rod and a rod having a higher thermal conductivity than that of the base material, the rod being embedded and fixed in the base material along a direction substantially normal to the second surface, and a part of the rod of the base material. A heat dissipation base material, which is exposed from the second surface. 2. The heat dissipation substrate according to claim 1, wherein one end of the rod projects from the second surface of the base material. 3. The heat dissipating base material according to claim 1, wherein one end of the rod has a flat end surface included in substantially the same plane as the second surface of the base material. 4. The base material is made of copper or a copper alloy, and the rod is a carbon fiber-reinforced carbon composite material, a carbon-based metal composite material, or a carbon fiber / metal composite material containing carbon fiber-reinforced metal, or high heat. The heat dissipating base material according to claim 1, wherein the heat dissipating base material is made of at least one of conductive metal materials. 5. The base material is Cr, Mo, W, C, Si
At least 1 selected from the group consisting of C and AlN
The heat dissipating base material according to claim 4, wherein the heat dissipating base material is made of a copper alloy containing 5 to 40 volume% of one additive component. 6. The heat dissipating base material according to claim 5, wherein the base material is made of a copper alloy containing the additive component dispersed as fine powder having a particle diameter of 100 μm or less. 7. The rod comprises Cu, Ni, Au, W,
The heat dissipating base material according to claim 4, wherein the heat dissipating base material is covered with a coating layer whose main component is a component selected from the group consisting of SiC and SiC. 8. The base material and the rod exposed from the base material are covered with a coating layer containing a component selected from the group consisting of Cu, Ni, Au, W, and SiC as a main component. The heat dissipation base material according to claim 4. 9. The rods are made of different materials,
The heat dissipating base material according to claim 4, comprising a plurality of rods. 10. A method for manufacturing a heat dissipation substrate, which comprises a base material and a rod having one end exposed from the base material, comprising at least one of a carbon fiber / metal composite material and a high thermal conductivity metal material. A rod preparing step of preparing a rod, an arranging step of arranging the rod in a molding die, a step of filling the molding die with a powder containing copper as a main component, and filling one end of the rod, A step of pressurizing the powder with a pressure of 0.1 to 5 tonf / cm ² to form a powder compact with one end of a rod embedded; Inside,
Heating at a temperature of 700 to 1200 ° C. to sinter the green compact to form a base material. 11. The arranging step is a step of providing a supporting jig in the molding die and supporting the plurality of rods by the supporting jig so that the rods are substantially parallel to each other. The manufacturing method described in. 12. A method of manufacturing a heat dissipation substrate, which comprises a base material and a rod having one end exposed from the base material, the material comprising at least one of a carbon fiber / metal composite material and a high thermal conductivity metal material. A rod preparation step of preparing a rod, a step of pressurizing a powder containing copper as a main component at a pressure of 0.1 to 8 tonf / cm ² to form a green compact, and forming a hole in the green compact. Forming the rod, inserting the rod into the hole to expose one end of the rod from the powder compact, and inserting the rod into the powder compact in a non-oxidizing atmosphere.
Heating at a temperature of 700 to 1200 ° C. to sinter the green compact to form a base material. 13. A method of manufacturing a heat dissipation substrate, which comprises a base material and a rod having one end exposed from the base material, the material comprising at least one of a carbon fiber / metal composite material and a high thermal conductivity metal material. A rod preparing step of preparing a rod; a step of pressurizing a powder containing copper as a main component at a pressure of 0.1 to 8 tonf / cm ² to form a green compact; Heating in an atmosphere at a temperature of 400 to 700 ° C. to sinter the green compact to form a primary sintered body; forming a hole in the primary sintered body; Inserting the rod and exposing one end of the rod from the primary sintered body, and heating the primary sintered body with the rod inserted therein at a temperature of 700 to 1200 ° C. in a non-oxidizing atmosphere. And a step of further sintering the primary sintered body to form a base material. Method of manufacturing a wood. 14. The powder material containing copper as a main component is Cr,
A fine powder containing at least one component selected from the group consisting of Mo, W, C, SiC, and AlN is added in an amount of 5 to 4
The manufacturing method according to any one of claims 10 to 13, which comprises a powder mixed with copper powder at a ratio of 0% by volume. 15. The manufacturing method according to claim 14, wherein the particle size of the fine powder is 100 μm or less. 16. The rod preparing step comprises Cu, Ni,
14. The method according to claim 10, further comprising a step of covering the surface of the rod with a coating layer containing a component selected from the group consisting of Au, W, and SiC as a main component. 17. The surface of the base material and the surface of the rod exposed from the base material are Cu, Ni, Au, W, and S.
14. A step of covering with a coating layer containing a component selected from the group consisting of iC as a main component.
The manufacturing method described in. 18. A semiconductor device comprising: the heat dissipation base material according to claim 1; and a semiconductor element mounted on the first surface of the heat dissipation base material. A semiconductor device, wherein the rod exposed from the second surface is in contact with a cooling medium. 19. The heat dissipation substrate is attached to a heat dissipation container, and cooling water flowing in the heat dissipation container is in contact with the rod exposed from the second surface of the heat dissipation substrate. The semiconductor device according to claim 18. 20. The semiconductor device according to claim 18, wherein the cooling medium is a heat radiation fin attached to the second surface of the heat radiation substrate.