JPH10150124A - Heat generating semiconductor device mounting composite substrate and semiconductor device using the substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat generating semiconductor device mounting composite substrate having excellent heat discipating property and hardly generating cracks and exfoliation even when thermal stress is received. SOLUTION: This semiconductor device has a composite layer 2 and a metal layer 3 in thickness direction, and the composite layer 2 consists of the material formed by dispersing low heat expansion fiber-like or particle-like dispersing material into high heat conductive metal matrix 5, the metal layer 3 consists of the metal same as the metal matrix 5 of the composite layer 2, and a composite substrate 1, in which the metal of the metal layer 3 and the metal matrix 5 of the composite layer 2 are connected, is used. An excellent solderability metal film 9 is provided on the outer surface of the composite layer 2. Besides, a low heat expansion substrate 8, where a heat generating semiconductor device 7 is mounted, is mounted using solder 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composite substrate having good heat dissipation (or heat absorption) suitable for mounting a semiconductor device that generates heat, and a semiconductor device using the same.

[0002]

2. Description of the Related Art With the recent increase in size and integration of semiconductor devices, the amount of heat generated by the semiconductor devices has increased. The board on which the semiconductor device that generates heat is mounted
It is required that the coefficient of thermal expansion be as small as that of a semiconductor device so as not to generate thermal distortion, and that the material has excellent thermal conductivity in order to enhance heat dissipation.

[0003] As a substrate material having a small coefficient of thermal expansion, alumina, forsterite, mullite and the like are used as a ceramic material, and an Fe-Co alloy (Kovar) is used as a metal material.
Ni alloys such as 42 alloy are known. However, these materials have a drawback of low thermal conductivity. on the other hand,
As a substrate material having high thermal conductivity, copper, copper alloy, aluminum or aluminum alloy is generally used. However, these materials have a disadvantage that they have a large thermal expansion coefficient. For this reason, conventionally, a composite substrate was used in which a substrate with a small thermal expansion coefficient and a substrate with good thermal conductivity were joined with low-temperature solder, etc., and a heat-generating semiconductor device was mounted on the substrate side of the composite substrate with a small thermal expansion coefficient. I was trying to do it.

[0004]

However, since the above-described composite substrate for mounting a heat-generating semiconductor device is formed by bonding completely different materials, it is difficult to obtain a high bonding strength, and the heat generated by the heat generation of the semiconductor device is difficult. When subjected to stress repeatedly, there is a problem that cracks and peeling occur on the joint surface of the composite substrate, and the heat radiation performance is significantly reduced. Further, since a plate material having low thermal conductivity is used on the side on which the heat-generating semiconductor device is mounted, there is a problem that heat dissipation is low.

SUMMARY OF THE INVENTION In view of the above problems, it is an object of the present invention to provide a composite substrate for mounting a heat-generating semiconductor device, which is less likely to be cracked or peeled even when subjected to thermal stress and has good heat dissipation. It is to provide a semiconductor device.

[0006]

A composite substrate for mounting a heat-generating semiconductor device according to the present invention has a composite layer and a metal layer in a thickness direction, and the composite layer is formed of a high thermal conductive metal matrix and a low thermal expansion fiber. The metal layer is made of the same metal as the metal matrix of the composite layer, the metal of the metal layer and the metal matrix of the composite layer are continuous, and the outer surface side of the composite layer is A heat-generating semiconductor device or a mounting portion for a low-thermal-expansion substrate on which the heat-generating semiconductor device is mounted (claim 1).

The composite layer constituting the composite substrate of the present invention is obtained by dispersing a low thermal expansion dispersant in a metal matrix, so that the thermal expansion coefficient can be made sufficiently close to that of a semiconductor device. is there. For this reason, unreasonable stress is not applied to the junction with the heat-generating semiconductor device (or the low-thermal-expansion substrate on which the heat-generating semiconductor device is mounted), and the reliability can be improved. In addition, the metal matrix and the metal of the metal layer have high thermal conductivity and both are continuous (integrally without any intervening therebetween), so that the thermal conductivity in the composite substrate is extremely good. Yes, excellent heat dissipation performance can be exhibited, and there is little possibility of cracking or peeling occurring inside the composite substrate.

Further, the composite substrate for mounting a heat-generating semiconductor device of the present invention has a composite layer and a metal layer in the thickness direction, and the composite layer is dispersed in a metal matrix having a high thermal conductivity and a low thermal expansion fibrous or particulate dispersion. The metal layer is made of the same or similar metal as the metal matrix of the composite layer, the metal layer and the composite layer are joined, and the outer surface side of the composite layer is a heating semiconductor device or a heating semiconductor device. May be used as the mounting portion of the low thermal expansion substrate on which the substrate is mounted (claim 2).

This involves soldering the metal layer and the composite layer,
It is a type that is joined by brazing, welding, etc., but since the metal layer is composed of the same metal or a similar metal as the metal matrix of the composite layer, it is possible to increase the bonding strength between the metal layer and the composite layer. It is easy, and there is little possibility that cracking or peeling will occur inside the composite substrate. The same as the first aspect of the present invention, the joint part with the heat-generating semiconductor device is not subjected to excessive stress and the reliability is high.

In this case, when the composite layer and the metal layer are joined, deformation such as warpage occurs in the composite substrate due to thermal stress generated due to a difference in thermal expansion coefficient between the two, which may cause a problem. However, in such a case, the metal layer may be divided into a plurality of parts, and the composite layer may have a region joined to the metal layer and a region not joined (claim 3). With such a configuration, it is possible to avoid occurrence of warpage when joining the composite layer and the metal layer. In the case of this configuration, ultimately, a configuration in which a number of pin-shaped metal layers are connected to the composite layer is also possible. Further, it is also possible to improve heat dissipation by forming irregularities on each of the plurality of divided metal layers. In addition, in such a case, since the occurrence of deformation such as warpage of the composite substrate due to the heat history at the time of bonding is suppressed, in some cases, an Al-Ag-based brazing material (for example, BA4343, BA4343, or the like) may be used.
4045).

When a heat-generating semiconductor device or a low-thermal-expansion substrate on which a heat-generating semiconductor device is mounted is mounted on the composite layer of the heat-generating semiconductor device mounting composite substrate by soldering, the composite layer is dispersed. Since it contains a material, its solderability is worse than that of a metal that does not contain a dispersant. In particular, a composite layer in which a dispersant is dispersed in an Al matrix has poor solderability. For this reason, even if cracking or peeling does not occur inside the composite substrate, cracking or peeling may occur at the soldered portion between the composite layer and the heat generating semiconductor device or the low thermal expansion substrate on which the heat generating semiconductor device is mounted.

In order to solve such a problem, the present invention provides:
In the above-described composite substrate for mounting a heat-generating semiconductor device, a metal coating or a metal plate having good solderability is provided on the outer surface of the composite layer (claims 5 and 8). By providing such a metal coating or metal plate, the solderability between the composite layer and the heat-generating semiconductor device or the low-thermal-expansion substrate on which the heat-generating semiconductor device is mounted is improved, and cracking or peeling occurs at the soldered portions of both. The risk of occurrence is reduced.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment 1 FIG. 1 schematically shows a first embodiment of a composite substrate for mounting a heat-generating semiconductor device according to the present invention and a semiconductor device using the same. In the figure, 1 is a composite substrate for mounting a heat-generating semiconductor device, and 7 is a heat-generating semiconductor device. The composite substrate 1 has a composite layer 2 and a metal layer 3 in the thickness direction. That is, the substrate has the composite layer 2 partially in the thickness direction. The composite layer 2 is obtained by dispersing a low thermal expansion dispersant 4 in a metal matrix 5 having high thermal conductivity. Although the dispersing material 4 is drawn large in the drawing, it is very thin fibrous or very small particles. The metal layer 3 is composed of only the same metal 5 as the metal matrix 5 of the composite layer 2.
And the metal matrix 5 is continuous without any intervention.

The heat-generating semiconductor device 7 is joined to the outer surface of the composite layer 2 by solder 6. The heat generated in the semiconductor device 7 is radiated through the composite layer 2 and the metal layer 3.
The composite layer 2 has good thermal conductivity because the metal matrix 5 having good thermal conductivity fills the gaps of the dispersing material 4 and is connected like a sponge. The composite layer 2 and the metal layer 3 also have a good thermal conductivity. Since the second metal matrix 5 and the metal layer 3 are continuous, the thermal conductivity is good, and the metal layer 3 also has good thermal conductivity. Therefore, extremely excellent heat dissipation performance can be obtained. In addition, since the composite layer 2 has the low thermal expansion dispersing material 4 dispersed therein, the thermal expansion coefficient is much lower than that of the case of using only metal, and can be substantially the same as that of the semiconductor device 7. Therefore, even if there is a change in the temperature of the semiconductor device 7, unreasonable stress does not easily occur at the junction between the semiconductor device 7 and the composite layer 2.

It is preferable to form irregularities on the outer surface of the metal layer 3 as shown in FIG.
Further, the surface of the metal layer 3 can be made flat.

As the material constituting the metal layer 3 and the metal matrix 5 of the composite layer 2, it is appropriate to use copper, copper alloy, aluminum or aluminum alloy.

As the dispersing material 4 constituting the composite layer 2, ceramic materials such as Al ₂ O ₃ , mullite, and Al
N, SiC, SiO ₂ , ZrO ₂ , Si ₃ N ₄ , TiB
₂ , ZrB ₂ , 9Al ₂ O ₃ .2B ₂ O ₃ , K ₂ Ti ₆
O ₁₃ and C can be used. As the metal material, an invar alloy, a shape memory alloy, W, Mo, Si, or the like can be used. In the case of intermetallic compounds, Ni ₃ Al, Nb ₃ Al, FeAl
₃ etc. can be used. These dispersants are used in the form of fibers or particles (powder). The dispersing material is appropriately selected and used depending on required specifications such as cost, thermal expansion characteristics, thermal conductivity, and electrical characteristics. Not only one dispersant but also two or more dispersants can be dispersed according to required characteristics. Further, by changing the volume filling ratio of the dispersant, the thermal conductivity and the thermal expansion coefficient of the composite layer can be adjusted.

Although not shown, the heat generating semiconductor device mounting composite substrate may have an insulating layer on the surface on which the heat generating semiconductor device is mounted. Since the composite layer of the composite substrate is conductive, it is necessary to provide an insulating layer when it is necessary to electrically insulate the semiconductor device and the substrate. By providing an insulating layer, a circuit pattern can be formed on the surface.

The composite layer of the composite substrate for mounting a heat-generating semiconductor device has the highest filling rate of the dispersant on the surface side, and
It is preferable that the lower the inner part, the lower. This makes it easy to bring the coefficient of thermal expansion near the surface of the composite layer close to the coefficient of thermal expansion of the semiconductor device, and further enhances the thermal conductivity inside the composite substrate.

When a fibrous dispersing material is used for the composite layer, it is preferable to orient the fibrous dispersing material in a direction in which thermal expansion of the composite layer is to be suppressed. Thereby, the thermal expansion property of the composite layer can be more effectively reduced.

[Embodiment 2] FIG. 2 shows a second embodiment of the present invention. FIG. 1 shows a case where the composite layer 2 is present on the entire surface. However, the embodiment of FIG. 2 has a form in which the composite layer 2 is present in an island shape in a region where the heat-generating semiconductor device 7 is mounted. Alternatively, the composite layer 2 may be formed in a band shape through a region where the semiconductor device 7 is mounted. The form in which the composite layer 2 exists in the shape of an island or a strip requires less use of the dispersing material, is advantageous in cost, and has good heat dissipation. In FIG. 2, the same parts as those in FIG. 1 are denoted by the same reference numerals. Configurations, materials used, modified modes, and the like other than those described above are the same as those in the first embodiment, and a description thereof will not be repeated.

[Embodiment 3] FIG. 3 shows a third embodiment of the present invention. FIG. 1 shows a case where the heat-generating semiconductor device 7 is directly soldered on the composite layer 2. However, in the embodiment of FIG. 3, the low thermal expansion substrate 8 on which the heat-generating semiconductor device 7 is mounted is mounted on the composite layer 2. It is joined by solder 6. As the low thermal expansion substrate 8, for example, a DBC (direct bonding copper) substrate having a copper layer provided on both surfaces of an alumina plate is used. In FIG. 3, the same parts as those in FIG. 1 are denoted by the same reference numerals. In addition, the configuration other than the above, the materials used, the modified aspects, and the like are the same as those in the first embodiment, and a description thereof will not be repeated. Further, the composite substrate 1 may be formed as shown in FIG.

[Embodiment 4] FIG. 4 shows a fourth embodiment of the present invention. In this embodiment, a metal film 9 having good solderability is provided on the outer surface of the composite layer 2, and a low thermal expansion substrate 8 on which a heat generating semiconductor device 7 is mounted is bonded thereon by solder 6. The material of the metal film 9 having good solderability is Cu, Ni, Pd, Sn, Au or A
g etc. are used. The composite layer 2 generally has poor solderability because it contains the dispersing material 4, but by providing the metal coating 9 on the outer surface of the composite layer 2 as described above, the solderability can be improved, and the composite layer 2 can be subjected to thermal stress. When cracking or peeling occurs at the soldered portion when the soldering is performed, the occurrence of cracking or peeling can be suppressed.
When the metal matrix 5 of the composite layer 2 is made of aluminum or aluminum alloy, it is particularly preferable to make the structure as shown in FIG.

The metal film 9 may be a single layer, but may be a laminate of two or more of the above materials depending on required characteristics.

The metal coating 9 is formed by plating or other means. In order to enhance the adhesion between the composite layer 2 and the metal coating 9, as shown in FIG. Then, a metal coating 9 may be formed thereon.

In order to enhance the adhesion between the composite layer 2 and the metal coating 9, as shown in FIG. 6, a part of the dispersion material 4 is projected from the outer surface of the composite layer 2, and the metal coating 9 is coated thereon. It is also effective to form them so that the protrusions of the dispersion material 4 bite into the metal coating 9. In order to obtain such a structure, the metal matrix 5 on the surface of the composite layer 2 is etched to a depth of 5 to 50 μm, and then a metal coating 9 having good solderability is formed on that portion to a thickness larger than the above etching depth. Good. In the case of the structure shown in FIG. 6, a fibrous material is used as the dispersing material 4, and 50% or more of the dispersing material 4 is oriented in the direction of θ = 30 ° to 90 ° with respect to the surface of the metal coating 9. It is preferable to be in a state in which

In FIG. 4, the same parts as those in FIG. 1 are denoted by the same reference numerals. In addition, the configuration other than the above, the materials used, the modified aspects, and the like are the same as those in the first embodiment, and a description thereof will not be repeated. Further, the composite substrate 1 may be formed as shown in FIG. Further, the heat generating semiconductor device 7 can be directly soldered to the surface of the metal film 9.

[Embodiment 5] FIG. 7 shows a fifth embodiment of the present invention. In this embodiment, an island-shaped or band-shaped metal coating 9 having good solderability is formed on the outer surface of the composite layer 2 in a region where the low thermal expansion substrate 8 on which the heat-generating semiconductor device 7 is mounted is soldered. . Otherwise, FIGS. 4 to 6
Since the fourth embodiment is the same as the fourth embodiment, the same portions are denoted by the same reference numerals and description thereof will be omitted.

[Embodiment 6] FIG. 8 shows a sixth embodiment of the present invention. This embodiment is an example in which a composite layer 2 and a metal layer 3 constituting a composite substrate 1 for mounting a heat generating semiconductor device are joined via a solder layer 10. With such a configuration, the thermal conductivity in the thickness direction in the composite substrate 1 is lower than in the case where the metal matrix 5 of the composite layer 2 and the metal of the metal layer 3 are continuous, but the thickness of the solder layer 10 is still lower. If the thickness is reduced (for example, to about 0.1 to 0.4 mm), sufficient heat radiation performance can be obtained. In the case of this composite substrate, the metal layer 3 is made of the same metal or a similar metal as the metal matrix 5 of the composite layer 2. This is to ensure the bonding by the solder layer 10 and to prevent cracking or peeling at the bonding surface when subjected to thermal stress. For example, when the metal matrix 5 of the composite layer 2 is Al or an Al alloy, the metal layer 3 is made of Al or an Al alloy.
-Use Zn solder.

In this embodiment, a metal film 9 having good solderability is formed on the outer surface of the composite layer 2 and a low thermal expansion substrate 8 on which a heat-generating semiconductor device 7 is mounted is formed thereon.
However, since this point is the same as that of the fourth embodiment shown in FIGS. 4 to 6, detailed description is omitted. The metal coating 9 can be partially formed as in Embodiment 5 of FIG. The heating semiconductor device 7 has a metal coating 9.
It is also possible to solder directly onto the composite layer 2 without providing the metal coating 9. Note that the configuration, materials used, modified modes, and the like other than those described above are the same as those in the first embodiment, and a description thereof will not be repeated.

Embodiment 7 FIG. 9 shows a seventh embodiment of the present invention. In this embodiment, as in the sixth embodiment, the composite layer 2 and the metal layer 3 are joined via the solder layer 10. However, the metal layer 3 is divided into a plurality, and the composite layer 2 is This is an example having a region that is joined and a region that is not joined. With such a configuration, when the metal layer 3 is bonded to the composite layer 2, the metal layer 3 and the composite layer 2
Can reduce the occurrence of thermal stress due to the difference in thermal expansion coefficient of the semiconductor substrate, and can more reliably prevent deformation such as warpage of the heat-generating semiconductor device mounting composite substrate 1.

In such a form, since the generation of thermal stress in the composite layer 2 and the metal layer 3 is suppressed, as shown in FIG. S
i-type brazing material 13 (eg, BA4343, BA4045)
) Can be joined at a higher temperature than in the case of solder. By joining with the brazing material 13, when mounting the heat-generating semiconductor device 7 or the low thermal expansion substrate 8 on which the heat-generating semiconductor device 7 is mounted on the composite layer 2, it is possible to use a higher temperature solder, and assemble. There is an advantage that the degree of freedom is improved.

Further, a layer of solder or brazing material is provided in advance on the surface (inner surface) of the composite layer 2 where the metal layer 3 is joined, and the divided metal layers 3 are fixed to the composite layer 2 at once by a jig. If you do soldering or brazing in the state,
It is also possible to increase mass productivity. 9 and FIG.
Although not shown at 0, also in this embodiment, a metal film is formed on the outer surface of the composite layer 2 in order to improve the bonding property with the heat-generating semiconductor device or the low thermal expansion substrate on which the heat-generating semiconductor device is mounted. Is also possible. Configurations, materials used, modified modes, and the like other than those described above are the same as those in the first embodiment, and a description thereof will not be repeated.

[Embodiment 8] FIG. 11 shows an eighth embodiment. In this embodiment, in the same manner as in the seventh embodiment, the metal layers 3 divided into the composite layers 2 are joined, and the metal layers 3a further divided into smaller pieces are joined on the respective metal layers 3 to form irregularities. It was done. With such a configuration, the surface areas of the metal layers 3 and 3a are increased, and heat dissipation is improved.

In FIG. 11, the metal layer 3a is formed on the metal layer 3.
Are formed by bonding, but it is also possible to form the unevenness by machining the metal layer 3. Although not shown in FIG. 11, also in this embodiment, a metal film is formed on the outer surface of the composite layer 2 in order to improve the bonding property with the heat-generating semiconductor device or the low thermal expansion substrate on which the heat-generating semiconductor device is mounted. It is also possible.
Configurations, materials used, modifications, and the like other than those described above are the same as those in the seventh embodiment, and a description thereof will not be repeated.

Embodiment 9 FIG. 12 shows a ninth embodiment of the present invention. In this embodiment, a metal plate 11 having good solderability is joined to the outer surface of the composite layer 2, and a low thermal expansion substrate 8 on which a heat-generating semiconductor device 7 is mounted is joined by solder 6. As a material of the metal plate 11 having good solderability, Cu, Ni, Pd, Sn, Au, Ag, or the like is used. Although the composite layer 2 generally has poor solderability because it contains the dispersing material 4, as described above, the composite layer 2
By joining the metal plate 11 to the outer surface of the substrate, the solderability can be improved, and the occurrence of cracks and peeling at the soldered portion when subjected to thermal stress can be suppressed. When the metal matrix 5 of the composite layer 2 is made of aluminum or aluminum alloy, it is particularly preferable to make the structure as shown in FIG.

The metal plate 11 may be a single plate, or may be a composite plate in which two or more layers of the above materials are laminated depending on required characteristics.

The joining of the composite layer 2 and the metal plate 11 is performed by setting a laminate of the porous molded body of the dispersing material 4 and the metal plate 11 in a mold, and forging a metal matrix melt for the composite layer by forging. Can be carried out by pressure casting. This makes it possible to obtain a composite substrate having good mass productivity, low cost, and high bonding strength as compared with forming a metal film on the outer surface of the composite layer by plating.

When the composite layer 2 and the metal plate 11 are joined by pressure casting of a metal matrix, it is preferable to form fine irregularities on the surface of the metal plate 11 on the composite layer 2 side. By forming such irregularities, the bonding area at the interface between the metal plate 11 and the composite layer 2 increases, and the bonding strength between the two can be increased.

The thickness of the metal plate 11 is preferably 0.5 to 2 mm. When the thickness is smaller than 0.5 mm, when forming the composite layer by pressure casting such as melt forging or the like, the metal plate 11 is easily deformed or diffused and lost depending on the material, which is not preferable. On the other hand, if the thickness is more than 2 mm, the effect of the metal plate 11 on the thermal expansion characteristics becomes strong, and sufficient matching of thermal stress cannot be obtained at the interface with the low thermal expansion substrate 8.

In FIG. 12, the same parts as those in FIG. 1 are denoted by the same reference numerals. In addition, the configuration other than the above, the materials used, the modified aspects, and the like are the same as those in the first embodiment, and a description thereof will be omitted. Further, the composite substrate 1 may be formed as shown in FIG. Further, the heat generating semiconductor device 7 can be directly soldered to the outer surface of the metal plate 11.

[Embodiment 10] FIG. 13 shows a tenth embodiment of the present invention.
An embodiment will be described. In this embodiment, the low thermal expansion substrate 8 on the outer surface of the composite layer 2 on which the heat-generating semiconductor device 7 is mounted is provided.
Is formed in the region where the is soldered, a metal plate 11 having good solderability in an island shape or a band shape. The other parts are the same as those in the ninth embodiment of FIG. 12, and the same parts are denoted by the same reference numerals and description thereof will be omitted.

[Embodiment 11] FIG. 14 shows an eleventh embodiment of the present invention.
An embodiment will be described. In this embodiment, metal plating 12 is applied to the surface of the metal plate 11 on the side of the composite layer 2 to increase the bonding strength with the composite layer 2. Composite layer 2 and metal plate 1
Bonding with the first metal mold 1 is performed by setting a laminate of the porous molded body of the dispersing material 4 and the metal plate 11 in a mold, and casting a metal matrix melt for the composite layer by means of melt forging or the like. When the metal matrix 5 is made of Al or an Al alloy, it is preferable to provide the metal plating 12 as described above in order to increase the bonding strength with the metal plate 11. The other parts are the same as those in the ninth embodiment of FIG. 12, and the same parts are denoted by the same reference numerals and description thereof will be omitted.

[0044]

【Example】

 [Example 1] SiC fibers (average diameter 0.3
μm, average length 90 μm), 9Al _TwoO_Three・ 2B_TwoO_Three
Fiber (average diameter 0.5 μm, average length 30 μm), Al
Using N fibers (average diameter 1 μm, average length 30 μm)
The volume filling ratio (Vf) is 40%, 5
0% and 60% porous fiber molded bodies were produced. Dimension is 1
It is 00 mm x 100 mm x 5 mm. This porous fiber
Set the compact in the cavity of the pressure casting machine,
Pressure casting was performed using Al and Cu as the molten metal.
This allows low thermal expansion in the metal matrix in the thickness direction
Composite layer in which conductive fibers are dispersed
A composite substrate for mounting a heat-generating semiconductor device having a metal layer
Made.

A sample was taken from the composite layer portion of the manufactured composite substrate and heated at a heating condition of 50 ° C./min.
The coefficient of thermal expansion and the thermal conductivity up to were measured. Table 1 shows the results. For comparison, Table 2 shows the measurement results of the thermal expansion coefficient and thermal conductivity of Al, Cu, 99% alumina, and forsterite.

[0046]

[Table 1]

[0047]

[Table 2]

According to Tables 1 and 2, the composite layer of this composite substrate has a thermal expansion characteristic comparable to that of alumina,
It can be seen that it has a heat conduction characteristic close to u.

Next, SiC (60 V
f%) / Al substrate and 9Al ₂ O ₃ .2B ₂ O ₃ (60
Using a Vf%) / Al substrate, a semiconductor device was joined to the surface on the composite layer side with solder. The semiconductor device manufactured in this manner was subjected to a thermal stress test by a temperature change. In this test, the semiconductor device was heated from room temperature to about 180 ° C
One heat stress was to generate heat and then return to normal temperature, and the number of heat stresses at the time when the joints of the members and the members themselves deteriorated was used as an evaluation scale. Table 3 shows the results.

For comparison, a conventional alumina / Cu / Al composite substrate, a forstenite / Cu / Al composite substrate, Si
The same test was performed on a semiconductor device using a C / Cu / Al composite substrate, and the results are also shown in Table 3. In addition, the ceramic plate (alumina etc.) and C
The bonding of the u plate was performed by soldering, and the bonding of the Cu plate and the Al plate (for heat sink) was performed by heat conductive grease.

[0051]

[Table 3]

As described above, the semiconductor device of the present embodiment hardly causes deterioration such as cracks at the interface, and can secure higher reliability than the conventional semiconductor device.

Example 2 Cu-16.7 as a dispersant
wt% Zn-7.1 wt% Al alloy (shape memory alloy) particles, Ni-50 wt% Ti alloy (shape memory alloy) particles,
Fe-36 wt% Ni alloy (invar alloy) particles were used, and as the metal matrix material, 99.7% pure Al particles and 99.99% pure Cu particles were used. In each case, the size of the particles is 100 mesh.

When the dispersant is shape memory alloy particles, 500
After hydrogen annealing at 1 ° C. × 1 hour, the next step was carried out as it was in the case of the Invar alloy particles. The dispersing material and the matrix material have a volume filling rate (Vf) of the dispersing material of 10%,
20% and 30% are blended and 2
Mix for 4 hours. Next, the mixed powder was 88 mm in diameter and 30 mm in height.
mm compacted into a disk with a diameter of 90 mm.
m, AA1070 having an outer diameter of 100 mm and a length of 1180 mm
The aluminum alloy tube was housed in a stacked manner, and lids of the same material were electron-beam welded to both ends of the aluminum alloy tube in a vacuum.

The billet manufactured in this manner was replaced with 350
It heated at 30 degreeC for 30 minutes, and extruded in the plate shape of thickness 10mm and width 50mm. Next, after removing the AA1070 alloy of the outer layer, it was cut to a length of 1200 mm and rolled in a direction perpendicular to the extrusion direction until the thickness became 1.7 mm. As described above, a composite plate in which the low thermal expansion particles were dispersed in the metal matrix was obtained.

Next, the composite plate was set in a cavity of a pressure casting machine, and on one surface thereof, a molten aluminum was cast when the metal matrix was Al, and a molten Cu was cast when the metal matrix was Cu. When the dispersion material was Invar alloy particles, a composite substrate having a composite layer and a metal layer in the thickness direction was obtained. When the dispersing material was shape memory alloy particles, a heat treatment for memorizing the shape was performed, and then a cold work by cross rolling was performed by about 0.08% to obtain a composite substrate.

A sample was taken from the composite layer portion of the composite substrate thus obtained, and the thermal expansion coefficient and the thermal conductivity were measured under the same conditions as in Example 1. Table 4 shows the results. For comparison, W-15wt% Cu alloy, Al-30w
The thermal expansion coefficient and the thermal conductivity of the t% Si alloy and Kovar were also measured, and the results are shown in Table 5.

[0058]

[Table 4]

[0059]

[Table 5]

Tables 4 and 5 show that the composite layer of this composite substrate has a smaller coefficient of thermal expansion and a higher thermal conductivity than the conventional substrate material.

Next, of the composite substrates obtained as described above, a Cu—Zn—Al (20 Vf%) / Al substrate, a Ni—Ti (20 Vf%) / Al substrate, and a Fe—N
Using an i (20 Vf%) / Al substrate, a semiconductor device was joined to the surface on the composite layer side with solder. The semiconductor device thus obtained was subjected to the same thermal stress test as in Example 1. Table 6 shows the results.

[0062]

[Table 6]

As described above, in the semiconductor device of this embodiment, deterioration such as cracks at the interface hardly occurs, and higher reliability can be secured than the conventional semiconductor device shown in Table 3.

Example 3 A mixture of SiC fibers (average diameter 0.3 μm, average length 90 μm) and C fibers (average diameter 40 μm, average length 400 μm) was used as a dispersant.
_{9Al 2 O 3 · 2B 2 O} 3 fibers (average diameter 0.5 [mu] m,
Mixture of AlN particles (average length 30 μm) and AlN particles (particle diameter about 50 μm), AlN fiber (average diameter 1 μm, average length 30 μm)
m) and a mixture of ZrO ₂ particles (particle size: about 50 μm), each having a volume filling factor (Vf) of 3
0%, 40% and 50% porous molded bodies were produced. The dimensions are 100 mm × 100 mm × 5 mm.

This porous compact was set in a cavity of a pressure casting machine, and pressure casting was performed using Al and Cu as a matrix melt. As a result, a composite substrate having a composite layer in which low thermal expansion fibers and particles were dispersed in a metal matrix in the thickness direction and a metal layer containing only the metal matrix was manufactured. A sample was taken from the composite layer portion of the manufactured composite substrate, and the same thermal expansion coefficient and thermal conductivity as in Example 1 were measured. Table 7 shows the results.

[0066]

[Table 7]

According to Tables 7 and 2, the composite layer of this composite substrate has a thermal expansion characteristic comparable to that of alumina,
It turns out that it has a heat conduction characteristic close to 1 and Cu.

Next, among the above-mentioned composite substrates, SiC (20
Vf%) + C (20Vf% ) / Al substrate and, 9Al ₂ O
_{3 · 2B 2 O 3 (20Vf} %) + AlN (20Vf%)
A semiconductor device was manufactured by using a / Al substrate and bonding a semiconductor device to the surface on the composite layer side with solder. The same heat stress test as in Example 1 was performed on these semiconductor devices. Table 8 shows the results.

[0069]

[Table 8]

As described above, in the semiconductor device of this embodiment, deterioration such as cracks at the interface hardly occurs, and higher reliability than the conventional semiconductor device shown in Table 3 can be secured.

Example 4 As a dispersant, SiC fiber (flat fiber) was used.
Average diameter 0.3μm, average length 90μm), 9Al _TwoO_Three
・ 2B_TwoO_ThreeFiber (average diameter 0.5 μm, average length 30
μm), AlN fiber (average diameter 1 μm, average length 30 μm)
m) and the volume filling ratio (Vf) of each fiber
Manufactures 40%, 50% and 60% porous fiber moldings
Was. The dimensions are 100 mm × 100 mm × 5 mm. This
With a cavity of the same shape
And set it as a matrix melt
Pressure casting is performed using l-Si 7% and Al, respectively.
Was. This results in low thermal expansion fibers in the metal matrix
A dispersed composite plate was produced.

The prepared composite plate was degreased and surface-modified at 50 ° C. for 70 seconds with an alkali solution (sodium hydroxide) as a pretreatment, and further, zinc coating was applied so that the Zn base was 1-2 μm thick. I gave it. Ni plating was performed thereon at room temperature and at a current density of 4 A / cm ² to form a 10 μm thick Ni plating layer (metal coating) on the surface of the composite plate. On this Ni-plated composite board, a DBC substrate (70 m
(m × 70 mm × 1.2 mm) were joined with a normal eutectic solder to produce a semiconductor device.

For comparison, a DBC substrate on which a heat-generating semiconductor device was mounted was similarly bonded to a composite plate not subjected to Ni plating, thereby producing a semiconductor device.

The semiconductor device thus manufactured was subjected to a thermal stress test by a change in temperature. In this test, after cooling from room temperature to −40 ° C., heat was generated to + 125 ° C., and a cycle of returning to room temperature was defined as one heat stress.
The purpose of this study is to examine the state of deterioration of each joint and the members themselves at the time of conducting the test 300 times, and the thermal resistance value of the semiconductor device. Table 9 shows the test results. The thermal resistance value is DB
A thermocouple was attached to the upper surface of the C substrate and the lower surface of the composite plate, and the temperature difference was measured as the temperature difference between the two surfaces when a constant output was generated in the semiconductor device.

[0075]

[Table 9]

According to Table 9, the composite plate having Ni plating (Example) has better solder jointability with the heat-generating semiconductor device-mounted DBC substrate, and peeling or cracking of the solder joint portion even when subjected to thermal stress. It turns out that it is hard to produce.

In this embodiment, a composite board having no metal layer is used in place of the composite board of the present invention, and the thermal resistance between the composite board and the heat-generating semiconductor device mounting DBC board and the presence or absence of peeling and cracking It is clear that even when the composite substrate of the present invention is used, the same result as in this embodiment can be obtained between the composite layer and the heat-generating semiconductor device mounting DBC substrate. This point is the same in the following fifth embodiment.

Example 5 Various kinds of porous fiber moldings using C fibers (average diameter 10 μm, average length 200 μm) as the dispersing material and having a volume filling ratio of 40%, 50% and 60% of the fibers. Was made. The dimensions are 100mm x 100mm x
5 mm. This porous fiber molded body was set in a pressure casting machine having a cavity having the same shape as the porous fiber molded body, and pressure casting was performed using Al-Si 7% as a matrix melt. In this way, a composite plate in which C fibers having low thermal expansion were dispersed in a metal matrix was manufactured.

The surface of the manufactured composite plate was electroplated with C
A plating layer (metal coating) of u, Ni, Pd, Sn, Au, and Ag was formed. The thickness of the plating layer was 5 μm. A DBC substrate (70 mm × 70 mm × 0.5 m) on which a heat-generating semiconductor device is mounted is placed on these plated composite layers.
m) was joined by a normal eutectic solder to produce a semiconductor device.

For comparison, a composite board having no heat-treated semiconductor device was similarly mounted on an unplated composite board.
A semiconductor device was manufactured by bonding the BC substrates. A thermal stress test was performed on the semiconductor device manufactured in this manner, and the number of times until destruction deterioration (peeling, cracking) occurred at the soldering interface was examined. In the thermal stress test, a cycle in which a semiconductor device is cooled from room temperature to −40 ° C., heated to + 180 ° C., and returned to room temperature is defined as one heat stress. The heat stress frequency was used as an evaluation scale. Table 10 shows the results.

[0081]

[Table 10]

According to the above results, the composite layer having the plating layer (embodiment) is better than the heat generating semiconductor device mounting DBC.
It can be seen that the solder joint property with the substrate is good, and peeling and cracking are unlikely to occur at the solder joint part even when subjected to thermal stress.
The reason why the number of times of destruction and deterioration in Example 5 is lower than that in Examples 1 (Table 3), Example 2 (Table 6), and Example 3 (Table 8) is that the test conditions are severe. Conceivable.

[Embodiment 6] In this embodiment, a composite substrate for mounting a heat generating semiconductor device shown in FIG. 8 and a method of manufacturing a semiconductor device using the same will be described.

First, SiC fiber (average diameter 0.3 μm, average length 90 μm) as a dispersant, 9Al ₂ O ₃ .2B
₂ O ₃ fiber (average diameter 0.5 μm, average length 30 μm
m), AlN fiber (average diameter 1 μm, average length 30 μm)
m), and the volume filling rate (V
f) produced a porous fiber molded body having 40%. Dimension is 1
It is 00 mm x 100 mm x 5 mm. This porous fiber molded body was set in a pressure casting machine having a cavity having the same shape as that of the porous fiber molded body.
Each was press-cast. As a result, a composite plate in which the low thermal expansion fibers were dispersed in the metal matrix was manufactured.

The prepared composite plate was subjected to degreasing and surface modification at 50 ° C. for 70 seconds with an alkali solution (sodium hydroxide) as a pretreatment, and then a zinc undercoat was applied to a Zn underlayer of 1-2 μm. Applied to thickness. Ni plating was performed thereon at room temperature and at a current density of 4 A / cm ² to form a 10 μm thick Ni plating layer (metal coating) on the surface of the composite plate.

This Ni-plated composite plate was formed by using a metal plate (Al-Si 7%) serving as a heat sink and a 0.2 mm thick Sn-
A composite substrate was formed by bonding with Zn solder. N of this composite substrate
A heat-generating semiconductor device-mounted DBC substrate (70 mm × 70 mm × 1.2 mm) was joined on the i-plated layer by eutectic solder to produce a semiconductor device.

[Embodiment 7] In this embodiment, a composite substrate for mounting a heating semiconductor device shown in FIG. 10 and a method of manufacturing a semiconductor device using the same will be described. SiC as dispersant
Fiber (average diameter: 0.3 μm, average length: 90 μm) and C fiber (average diameter: 10 μm, average length: 200 μm) were used, and these fibers each had a volume filling factor (Vf) of 40.
% Of a porous fiber molded body was produced. Dimension is 100mm ×
It is 100 mm x 5 mm. This porous fiber molded body was set in a pressure casting machine having a cavity having the same shape as that of the porous fiber molded body, and pressure casting was performed using 22% of Al-Si as a matrix melt. As a result, a composite plate in which the low thermal expansion fibers were dispersed in the metal matrix was manufactured. A Ni plating treatment was performed on the manufactured composite plate in the same manner as in Example 6 to form a Ni plating layer (metal film) having a thickness of 10 μm on the surface of the composite plate.

100 Ni cylinders having a diameter of 5 mm and a length of 25 mm as metal layers were almost uniformly dispersed and joined to this Ni-plated composite plate. Joining was performed in the following procedure. That is, the composite plate is horizontally arranged with the non-plated surface facing upward, and 100 sheets of flux-applied brazing filler metal sheets (BA4045) having a diameter of about 7 mm are arranged vertically and horizontally on each of the brazing filler metal sheets. Stand up the Al cylinder and weigh about 2k on it
g of weight. Next, this was left in a furnace maintained at 595 ° C. for 10 minutes to join the Al cylinder to the composite plate. A heating semiconductor device-mounted DBC substrate (70 m) is formed on the Ni plating layer of the composite substrate thus manufactured.
mx 70mm x 1.2mm) with eutectic solder
A semiconductor device was manufactured.

Example 8 As a dispersing agent, SiC fiber (flat
Average diameter 0.3μm, average length 90μm), 9Al _TwoO_Three
・ 2B_TwoO_ThreeFiber (average diameter 0.5 μm, average length 30
μm), AlN fiber (average diameter 1 μm, average length 30 μm)
m), C fiber (average diameter 20 μm, average length 70 μm)
, The volume filling rate of the fibers (V
f) 40%, 50%, 60% of various porous fiber moldings
Made a body. The dimensions are 100mm x 100mm x 5mm
It is. Cu plate (dimensions) as a metal plate with good solderability
(100 mm × 100 mm × 1 mm).

The above-mentioned porous fiber molded body and metal plate were preheated to 700 ° C. in a preheating furnace. The inside of the furnace was kept in an argon atmosphere in consideration of oxidation deterioration of the metal plate. Next, as shown in FIG. 15, the preheated metal plate 11 and the porous fiber molded body 4P were set in a casting mold 13 preheated to 250 ° C. in a laminated state. Then, after clamping with a pressure casting apparatus by a molten metal forging method, a 750 ° C. Al-Si 7% alloy molten metal is poured from the gate 14 at an injection speed of 10 cm / sec.
After pressurizing and holding for 1 minute at a pressure of 0 atm, it was coagulated.
As a result, as shown in FIG.
1, a composite substrate 1 for mounting a heat-generating semiconductor device having a composite layer 2 and a metal layer 3 (heat sink portion).

Next, the obtained composite substrate was cut, and the interface between the metal plate and the composite layer was observed with an optical microscope. As a result, it was confirmed that the bonding state of the interface was good. For comparison, a composite substrate in which the surface of the composite layer was subjected to electrolytic Cu plating was manufactured.

A thermal shock test was performed on the composite substrate manufactured as described above. In this test, a heating atmosphere of 200 ° C. and a cooling atmosphere of −30 ° C. were prepared, and the composite substrate was alternately thrown into these atmospheres, and one cycle of heating and cooling was performed for one cycle.
As the number of times, the number of times that the interface between the composite layer and the metal plate or the Cu plating is broken is examined. In the detection of destruction, when the resistance value was increased by 20% with respect to the initial value by measuring the electric resistance, the destruction was regarded as destruction. Table 11 shows the results. According to the result, it was found that the bonding property of the interface is better in the case of joining the Cu plate than in the case of Cu plating.

[0093]

[Table 11]

Example 9 Using a C fiber (average diameter: 10 μm, average length: 200 μm) as a dispersant, a porous fiber molded body having a volume filling factor (Vf) of 40% was produced. The dimensions are 100 mm × 100 mm × 5 mm. Ni plate, Pd plate, metal plate with good solderability
Au plate, Ag plate (dimensions 100 mm x 100 mm x 1 m
m), and a 10 μm-thick Cu film is formed on one side of these metal plates by electrolytic plating in order to increase the bonding strength with the composite layer.
Plated.

The above-mentioned porous fiber molded body and the metal plate were preheated to 700 ° C. in a preheating furnace. The inside of the furnace was kept in an argon atmosphere in consideration of oxidation deterioration of the metal plate. Next, the preheated metal plate and the porous fiber molded body were set in a casting mold 13 preheated to 250 ° C. in a state where the Cu plating surface of the metal plate was laminated toward the porous fiber molded body side. Then, after clamping with a pressure casting device by a molten metal forging method, a 750 ° C. Al-Si 7% alloy molten metal is cast into the mold at an injection speed of 10 cm / sec, and after the casting, pressure is maintained at a pressure of 1000 atm for 1 minute. After that, it was solidified. As a result, as shown in FIG. 14, a composite substrate 1 for mounting a heat-generating semiconductor device having the metal plate 11, the Cu plating layer 12, the composite layer 2, and the metal layer 3 (heat sink portion) in the thickness direction is manufactured. did.

For comparison, a metal plate not subjected to Cu plating was prepared, and a composite substrate was manufactured in the same manner as described above. The same thermal shock test as in Example 8 was performed on these composite substrates. Table 12 shows the results. According to this result, it was found that the surface of the metal plate on the composite layer side was subjected to Cu plating to improve the bonding property at the interface.

[0097]

[Table 12]

[0098]

As described above, according to the present invention, the heat-generating semiconductor device has good heat-radiating properties, and the heat-generating semiconductor device has good heat dissipation inside the composite substrate or at the interface between the composite substrate and the heat-generating semiconductor device or the heat-generating semiconductor device-mounted low thermal expansion substrate. A highly reliable composite substrate for mounting a heat-generating semiconductor device and a semiconductor device which are less likely to be cracked or peeled off can be provided.
Therefore, it is possible to sufficiently cope with an increase in size and power of a semiconductor device.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a first embodiment of a heat generating semiconductor device mounting composite substrate and a semiconductor device using the same according to the present invention.

FIG. 2 is a cross-sectional view showing a second embodiment of the present invention.

FIG. 3 is a sectional view showing a third embodiment of the present invention.

FIG. 4 is a sectional view illustrating a fourth embodiment of the present invention.

5 is a cross-sectional view showing a preferred example of a joint between a composite layer and a metal film in the composite substrate of FIG. 4;

FIG. 6 is a sectional view showing another preferred example of a joint between the composite layer and the metal film in the composite substrate of FIG. 4;

FIG. 7 is a sectional view showing a fifth embodiment of the present invention.

FIG. 8 is a sectional view showing a sixth embodiment of the present invention.

FIG. 9 is a sectional view showing a seventh embodiment of the present invention.

FIG. 10 is a sectional view showing a modification of the seventh embodiment.

FIG. 11 is a sectional view showing an eighth embodiment of the present invention.

FIG. 12 is a sectional view showing a ninth embodiment of the present invention.

FIG. 13 is a sectional view showing a tenth embodiment of the present invention.

FIG. 14 is a sectional view showing an eleventh embodiment of the present invention.

FIG. 15 is an explanatory view showing an example of a method for joining a metal plate and a composite layer by pressure casting.

[Explanation of symbols]

 1: Composite substrate 2: Composite layer 3: Metal layer 4: Fibrous or particulate dispersion material having low thermal expansion characteristics 5: Metal matrix having high thermal conductivity characteristics 6: Solder 7: Heat generating semiconductor device 8: Low thermal expansion substrate 9: Metal coating 10: Solder layer 11: Metal plate 12: Metal plating 13: Brazing material

Claims (19)

[Claims] A composite layer (2) and a metal layer (3) are provided in a thickness direction, and the composite layer (2) is formed into a metal matrix (5) having a high thermal conductivity and a fibrous or particulate material having a low thermal expansion. Dispersion material (4) is dispersed, metal layer (3) is composite layer (2)
The same metal as the metal matrix (5), and the metal of the metal layer (3) and the metal matrix (5) of the composite layer (2)
And the outer surface side of the composite layer (2) is a mounting portion of the heat-generating semiconductor device (7) or a low thermal expansion substrate (8) on which the heat-generating semiconductor device (7) is mounted. Composite board for mounting heat-generating semiconductor devices. 2. A composite material comprising a composite layer (2) and a metal layer (3) in the thickness direction, wherein the composite layer (2) is formed of a high thermal conductive metal matrix (5) and a low thermal expansion fibrous or particulate material. Dispersion material (4) is dispersed, metal layer (3) is composite layer (2)
The composite layer (2) and the metal layer (3) are joined, and are made of the same or similar metal as the metal matrix (5) of
A composite substrate for mounting a heat-generating semiconductor device, wherein the outer surface side of the composite layer (2) is a mounting portion for a heat-generating semiconductor device (7) or a low thermal expansion substrate (8) on which the heat-generating semiconductor device (7) is mounted. . 3. The metal layer (3) is divided into a plurality of parts, and the composite layer (2) has a region joined to the metal layer (3) and a region not joined. 2. The composite substrate for mounting a heat-generating semiconductor device according to item 1. 4. A metal layer (10, 1) which functions as a solder or a solder is provided on the joint surface of the composite layer (2) with the metal layer (3).
The composite substrate for mounting a heat-generating semiconductor device according to claim 3, comprising: 5. The composite substrate for mounting a heat-generating semiconductor device according to claim 1, wherein a metal coating having good solderability is provided on an outer surface of the composite layer. 6. The composite substrate for mounting a heat-generating semiconductor device according to claim 5, wherein irregularities are formed on an outer surface of the composite layer (2) to enhance adhesion to the metal coating (9). 7. A method according to claim 5, wherein a part of the dispersion material projects from the outer surface of the composite layer, and the projection of the dispersion material penetrates the metal coating. Composite board for mounting semiconductor devices. 8. The composite substrate for mounting a heat-generating semiconductor device according to claim 1, wherein a metal plate having good solderability is joined to an outer surface of the composite layer. 9. The bonding between the composite layer (2) and the metal plate (11) is performed by forming a laminate of the porous formed body (4P) of the composite layer dispersing material (4) and the metal plate (11). 9. The method according to claim 8, wherein the layer metal matrix is cast by pressure.
2. The composite substrate for mounting a heat-generating semiconductor device according to item 1. 10. The heat-generating semiconductor device mounting according to claim 9, wherein irregularities are formed on the surface of the metal plate (11) on the side of the composite layer (2) so as to increase the bonding strength with the composite layer (2). For composite substrates. 11. The metal plate (11) according to claim 9, wherein a surface of the metal plate (11) on the side of the composite layer (2) is provided with metal plating (12) for increasing the bonding strength with the composite layer (2). Composite board for mounting heat-generating semiconductor devices. 12. The metal matrix (5) and the metal layer (3) are aluminum or an aluminum alloy.
The composite substrate for mounting a heat-generating semiconductor device according to any one of the above. 13. The composite substrate for mounting a heat-generating semiconductor device according to claim 1, wherein the metal matrix (5) and the metal layer (3) are copper or a copper alloy. 14. The composite substrate for mounting a heat-generating semiconductor device according to claim 1, wherein the composite layer (2) exists on one side of the metal layer (3) in an island shape or a band shape. 15. The composite substrate for mounting a heat-generating semiconductor device according to claim 1, wherein irregularities are formed on an outer surface of the metal layer (3) to enhance heat dissipation. 16. The heat-generating semiconductor device mounting according to claim 1, wherein the volume filling ratio of the dispersing material (4) of the composite layer (2) is highest on the outer surface side and lower toward the inside. For composite substrates. 17. The composite layer (2) includes a fibrous dispersant (4), and the fibrous dispersant (4) is a composite layer (2).
17. The particles are oriented in a direction to suppress thermal expansion of the particles.
The composite substrate for mounting a heat-generating semiconductor device according to any one of the above. 18. The composite substrate for mounting a heat-generating semiconductor device according to claim 1, further comprising an insulating layer on a surface on which the heat-generating semiconductor device (7) is mounted. 19. A heat-generating semiconductor device (7) or a heat-generating semiconductor device (7) on an outer surface side of a composite layer (2) of the heat-generating semiconductor device mounting composite substrate (1) according to any one of claims 1 to 18. ) Mounted low thermal expansion substrate (8)
A semiconductor device characterized by mounting thereon.