JP2003037198A - Package for housing semiconductor element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem that it is difficult for the package for housing a semiconductor element comprising a conventional heatsink base to reliably disperse heat since the thermal conductivity of the heatsink base is low. SOLUTION: The package for housing a semiconductor element comprises a heatsink base 3 provided with a placement part on which a semiconductor element 4 is placed, an insulating frame 1 fitted to the upper surface, and a lid 2 fitted to the upper surface of the insulating frame 1. The heatsink base 3 comprises a composite material layer 3a in which the porous body of tungsten or molybdenum is impregnated with copper and a copper layer 3b formed on its upper and lower surfaces. 30 μm<=t2<=300 μm while t2<=0.15×t1, where t1 is thickness of the composite material layer 3a and t2 is thickness of the copper layer 3b. Thus, the high heat of the semiconductor element 4 is efficiently dispersed and the thermal expansion factor of the heat sink base 3 is allowed to approach the insulating frame 1, for reliable junction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a package for accommodating semiconductor elements, and more particularly to a semiconductor element package having high heat generation such as gallium arsenide (GaAs), indium phosphide (InP), silicon (Si), etc. The present invention relates to a semiconductor element housing package for high reliability use.

[0002]

2. Description of the Related Art Conventionally, a semiconductor element housing package for housing a semiconductor element is generally made of an electrically insulating material such as an aluminum oxide sintered body, a mullite sintered body, a glass ceramic sintered body, and the like. An insulating base having a recess for accommodating a semiconductor element, and a plurality of wiring conductors made of metal powder such as tungsten, molybdenum, manganese, copper, and silver deposited and led from the recess of the insulating base to the outer surface, It is composed of a lid and a semiconductor element is adhered and fixed to the bottom surface of the recess of the insulating substrate with an adhesive such as glass, resin or brazing material, and each electrode of this semiconductor element is connected to a wiring conductor through a bonding wire. After electrically connecting and then joining the lid to the insulating base through a sealing material made of glass, resin, brazing material, etc., inside the container consisting of the insulating base and the lid A semiconductor device as a product by housing the heat-generating component such as a semiconductor element.

In this conventional package for accommodating semiconductor elements, since the aluminum oxide sintered body constituting the insulating base has a low thermal conductivity (about 15 W / mK), a large number of semiconductor elements are housed in the insulating base during operation. When the heat is generated, the heat cannot be satisfactorily dissipated into the atmosphere, and as a result, the semiconductor element is heated to a high temperature due to the generated heat,
The semiconductor device has the drawbacks of causing thermal damage to the semiconductor element and causing thermal changes in characteristics to cause malfunction.

Therefore, in a semiconductor element housing package for housing a semiconductor element with high heat generation, a composite metal material such as copper-tungsten or copper-molybdenum is used in order to dissipate the heat of the semiconductor element well through the insulating substrate. The heat dissipation component is provided so as to be located directly below the semiconductor element.

For example, a heat dissipation component made of a copper-tungsten composite material is composed of tungsten and copper in a matrix, and the thermal conductivity of the copper-tungsten composite material varies depending on the ratio, but is generally 150 to 200 W / It is about mK.

However, with the development of semiconductor elements such as power ICs and high frequency transistors that require a large current, the amount of heat generated by the semiconductor elements tends to increase year by year, and at present, a thermal conductivity of 250 W / mK or more is obtained. There is a demand for a heat dissipation component.

To solve this problem, Japanese Patent Laid-Open No. 6-26
In Japanese Patent Laid-Open No. 8115, a clad material of a first member (base material) made of molybdenum and a second member made of copper is used as a heat dissipation substrate for a semiconductor device. M. C. (Cu / Mo / Cu)
Structures are disclosed. This C. M. C. The thermal conductivity of the heat dissipation substrate for semiconductor devices made of the clad material of the structure is
Extremely high at over 200 W / mK.

Further, in Japanese Patent Laid-Open No. 6-268117, both main surfaces of a first member (base material) made of at least one metal material selected from the group consisting of tungsten-copper alloy and molybdenum-copper alloy. There is proposed a heat dissipation board for a semiconductor device in which a second member made of a metal material having copper as a main material is joined by either a hot uniaxial pressing method or a rolling method. / MK or higher thermal conductivity is achieved.

[0009]

However, the heat dissipation substrate for a semiconductor device disclosed in JP-A-6-268115 and JP-A-6-268117 has a thermal conductivity of about 250 W / mK.
Although it is very high, since the base material layer and the copper layer are laminated by a rolling method or a hot uniaxial processing method as a manufacturing method, when the insulating frame is joined as a heat dissipation base of the package for storing a semiconductor element, There is a problem that cracks are likely to occur at the interface between the base material layer and the copper layer due to thermal stress at the time of joining.

Further, since there is an interface between the copper layer and the base material layer, there is a problem that the thermal conductivity is lowered due to the contact resistance of both layers.

The present invention has been devised in view of the above-mentioned problems in the prior art, and an object thereof is to form a heat dissipation substrate with copper layers on both sides by an infiltration method of copper-tungsten or copper-molybdenum. As a result, the heat generated by the semiconductor element can be satisfactorily dissipated to the insulator, and the copper layer is formed by the infiltration method that is not the hot uniaxial method or the lamination such as rolling. Another object of the present invention is to propose a package for accommodating a semiconductor element capable of firmly and reliably joining an insulator and a heat dissipation base.

[0012]

A package for accommodating a semiconductor element according to the present invention surrounds a heat dissipating base having a mounting portion on which a semiconductor element is mounted and an upper surface of the heat dissipating base surrounding the mounting portion. A semiconductor element housing package comprising an insulating frame body attached as described above and a lid body attached to the upper surface of the insulating frame body, wherein the heat dissipation base is a porous body of tungsten or molybdenum and copper. 30 μm ≦ t2 ≦ 300 μm and t2, where a composite material layer impregnated with and copper layers formed on the upper and lower surfaces thereof are used and the thickness of the composite material layer is t1 and the thickness of the copper layer is t2. It is characterized in that ≦ 0.15 × t1.

In the package for storing a semiconductor element of the present invention, in the above structure, the composite material layer is formed by impregnating a porous body of tungsten or molybdenum with 10 to 25% by weight of copper. It is a thing.

Further, in the package for storing a semiconductor element of the present invention, in the above structure, the insulating frame is made of ceramics having a coefficient of thermal expansion of 6 to 8 ppm / ° C. (room temperature to 800 ° C.). Is.

According to the package for housing a semiconductor device of the present invention, the heat dissipation substrate is formed on the composite material layer formed by impregnating a porous body of tungsten or molybdenum with 10 to 25% by weight of copper and the upper and lower surfaces thereof. It consists of a copper layer and
Assuming that the thickness of the composite material layer is t1 and the thickness of the copper layer is t2, 30 μm ≦ t2 ≦ 300 μm and t2 ≦ 0.15 × t1. Therefore, a composite material obtained by impregnating a porous body of tungsten or molybdenum with copper. Compared to a heat dissipation substrate composed of only layers, the heat generated in the semiconductor element mounted on the heat dissipation substrate can first be dissipated in the horizontal direction in the plane by the copper layer in the vicinity of the surface, and at the same time, combined with the copper layer. Since it is continuously connected to copper in the material layer, the loss of heat conduction is small, and as a result, more heat can be released into the composite material layer. Further, since the inside of the composite material layer is a copper-tungsten material, a thermal conductivity of 200 W / mK or more is secured. As a result, the thermal conductivity of the heat dissipation base is reduced to 25
It is possible to make it extremely high, such as 0 W / mK or more.

The copper layers formed on the upper and lower surfaces of the composite material layer can be formed at the same time when the composite material layer is impregnated with tungsten or molybdenum by the infiltration method. Unlike the copper layer bonded by the rolling method, cracks hardly occur at the interface between the copper layer and the composite material layer due to the thermal stress when the insulating frame is joined to the heat dissipation base, and as a result, the heat dissipation base is It is possible to normally and stably operate the semiconductor element that is placed and accommodated in the package for a long period of time.

The heat dissipating base is composed of a composite material layer formed by impregnating a porous body of tungsten or molybdenum with copper, and copper layers formed on the upper and lower surfaces of the composite material layer. When the layer thickness is t2, 30
Since μm ≦ t2 ≦ 300 μm and t2 ≦ 0.15 × t1, copper having a large coefficient of thermal expansion as well as thermal conductivity occupies a large proportion in the mounting portion of the semiconductor element provided on the upper surface of the heat dissipation base. It is possible to bring the thermal expansion coefficient of the heat dissipation base close to that of the insulating frame.

In particular, when the composite material layer is formed by impregnating a porous body of tungsten or molybdenum with 10 to 25% by weight of copper, the thermal expansion coefficient of the heat dissipation substrate is 9.0.
Since the value is not more than ppm / ° C., the heat dissipation base and the insulating frame can be bonded to each other favorably and stably over a long period of time.

The thermal expansion coefficient of the insulating frame is 6 to 8 p.
When the ceramics of pm / ° C. (room temperature to 800 ° C.) are used, the thermal expansion coefficient of the heat dissipation base can be set to a value close to the thermal expansion coefficient of the insulating frame.
The heat dissipation base and the insulating frame can be bonded to each other satisfactorily and stably over a long period of time.

[0020]

DETAILED DESCRIPTION OF THE INVENTION The present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 shows an example of an embodiment of a package for accommodating a semiconductor element of the present invention, in which 1 is an insulating frame, 2 is a lid, 3 is a heat dissipating base, and 4 is a semiconductor element. The heat dissipating base 3 has a mounting portion on which the semiconductor element 4 is mounted at the center of the upper surface, and the insulating frame 1 is attached to the upper surface of the heat dissipating base 3 so as to surround the mounting portion. , These insulation frames 1
The lid 2 and the heat dissipating base 3 constitute a container for housing the semiconductor element 4.

The insulating frame 1 is an aluminum oxide sintered body.
It is made of ceramics, which is an electrically insulating material, such as a mullite sintered body and a glass ceramics sintered body, and is bonded and fixed to the heat dissipation base 3 and the brazing material 6. A metal layer (not shown) for brazing is formed at the joint of the insulating frame 1 with the heat dissipation base 3.

When the insulating frame 1 is made of, for example, an aluminum oxide sintered body, a suitable organic binder, a solvent, etc. are added to and mixed with a raw material powder made of aluminum oxide powder and glass powder such as borosilicate glass. Along with making a product, this sludge is made into a ceramic green sheet (ceramic green sheet) by adopting a doctor blade method or a calender roll method, and then these ceramic green sheets are appropriately punched and It is produced by stacking a plurality of sheets and firing at a temperature of about 1600 ° C.

Further, the insulating frame 1 is provided with a wiring conductor 8 extending from a portion surrounding the mounting portion of the semiconductor element 4 inside to the outer surface, and the wiring exposed inside the insulating frame 1 is formed. Each electrode of the semiconductor element 4 is electrically connected to one end of the conductor 8 via a bonding wire 5.

The wiring conductor 8 is made of a refractory metal such as tungsten or molybdenum, and a metal paste obtained by adding and mixing an appropriate organic binder, a solvent, or the like to a metal powder such as tungsten or molybdenum is used as the insulating frame 1. By printing and applying a predetermined pattern to the green sheet in advance by a conventionally known screen printing method or the like, the green sheet is adhered and formed from the inner side to the outer surface of the insulating frame 1.

When the exposed surface of the wiring conductor 8 is coated with a metal such as nickel and gold which has excellent corrosion resistance and bonding property of the bonding wire 5 to a thickness of 1 μm to 20 μm by plating, Wiring conductor 8
It is possible to effectively prevent the above-mentioned oxidative corrosion and to firmly connect the bonding wire 5 to the wiring conductor 8. Therefore, it is desirable that the exposed surface of the wiring conductor 8 be coated with a metal having excellent corrosion resistance such as nickel and gold and excellent bonding property in a thickness of 1 μm to 20 μm.

The heat dissipating substrate 3 has a mounting portion for the semiconductor element 4 on its upper surface, and the semiconductor element 4 is fixed to this mounting portion via an adhesive material 7 such as resin, glass, or brazing material. . When a brazing material is used as the adhesive material 7, a metal layer (not shown) for brazing is usually formed at the joint portion of the heat dissipation base 3 with the semiconductor element 4. The insulating frame 1 and the heat dissipation base 3 are joined by using a brazing material 6 made of a silver-copper alloy or the like, and melting and brazing the brazing material 6 in a reducing atmosphere at 600 to 900 ° C. To be done.

The heat dissipating base body 3 is, as shown in a schematic sectional view in FIG. 2, a composite material layer 3a formed by impregnating a porous body of tungsten or molybdenum with copper, and copper layers formed on the upper and lower surfaces thereof. 3b and. The heat dissipation base 3 has a function of absorbing heat generated by the operation of the semiconductor element 4 and dissipating the same into the atmosphere. The heat dissipation base 3 is manufactured by
A preformed porous body of tungsten or molybdenum is melt-impregnated with copper from the upper and lower surfaces by an infiltration method to form a composite material layer 3a. At that time, copper remaining on the upper and lower surfaces of the composite material layer 3a is a copper layer. Since the upper and lower surfaces are covered with 3b, the copper layer 3b is polished to leave a thickness of 30 to 200 μm. After that, if necessary, the corrosion resistance of the surface of the copper layer 3b is increased, and the brazing material 6 is added.
A plating layer (not shown) of nickel or the like is formed on the exposed surface for the purpose of improving the wettability with the adhesive 7 and the like.

In the heat dissipating substrate 3, the tungsten or molybdenum porous material forming the composite material layer 3a is prepared, for example, by mixing an appropriate amount of binder with tungsten powder or molybdenum powder having a central particle size of several μm to 100 μm.
It can be obtained by forming a pressed body under a pressure of about 1 t / cm ³ and firing and sintering the pressed body at a temperature of about 1500 ° C.

Then, the porous body is impregnated with copper to form the composite material layer 3a, and the copper layers 3b are formed on the upper and lower surfaces thereof. The copper layer 3b is usually formed by arranging, of the copper impregnated in the composite material layer 3a from the upper and lower surfaces of the porous body, the remaining part that cannot be completely impregnated inside the composite material layer 3a. To be done.

Then, in this heat dissipation substrate 3, as shown in FIG.
As shown in the inside, when the thickness of each of the upper and lower copper layers 3b is t2 and the thickness of the composite material layer 3a is t1, 30 μm
It is important that ≦ t2 ≦ 300 μm and t2 ≦ 0.15 × t1. When t2 <30 μm, the copper layer cannot dissipate more heat in the in-plane horizontal direction in the vicinity of the surface, so that it becomes difficult to satisfactorily dissipate the heat generated by the semiconductor element 4 into the atmosphere. There is a tendency for the element 4 to be destroyed by heat or to cause a thermal change in the characteristics to cause a malfunction. On the other hand, when t2> 300 μm, the semiconductor element 4
The proportion of copper occupying too much in the mounting portion of the element becomes too large, and the coefficient of thermal expansion becomes large.
And the bonding material 7, and between the insulating frame 1 and the heat dissipation base 3 and the bonding material 6 tend to be easily broken or peeled.

When t2> 0.15 × t1, similarly to the above, the proportion of copper in the mounting portion of the semiconductor element 4 becomes too large and the coefficient of thermal expansion becomes large, so that the semiconductor element 4 and the heat dissipation base 3 are There is a tendency that breakage or peeling easily occurs between the bonding material 7 and between the insulating frame 1 and the heat dissipation base 3 and the bonding material 6.

In addition, the content of copper with which the porous material of tungsten or molybdenum is impregnated in the composite material layer 3a is such that the thermal expansion coefficient of the heat dissipation base 3 is 6.5 to 9.0 ppm / ° C. In order to obtain a value close to the expansion coefficient, it is preferably set to 10 to 25% by weight. When the content of copper is less than 10% by weight, the thermal expansion coefficient of the heat dissipation base 3 becomes 6.0 ppm / ° C. or less,
There is a tendency that breakage or peeling easily occurs between the semiconductor element 4 and the heat dissipation base 3 and the bonding material 7, and between the insulating frame 1 and the heat dissipation base 3 and the bonding material 7. On the other hand, if it exceeds 25% by weight, the thermal expansion coefficient of the heat dissipation base 3 becomes 9.0 ppm / ° C. or more, so that the semiconductor element 4, the heat dissipation base 3 and the bonding material 7, and the insulating frame 1 and the heat dissipation base 3 are provided. And joining material 7
Tends to be easily broken or peeled.

With respect to the heat dissipating base body 3, the thermal expansion coefficient of the insulating frame body 1 is set so that the thermal expansion coefficient of the heat dissipating base body 3 is close to the thermal expansion coefficient of the insulating frame body 1. It is preferably made of ceramics having a coefficient of 6 to 8 ppm / ° C (room temperature to 800 ° C). As such a ceramic, an aluminum oxide sintered body, a glass ceramic sintered body, or the like may be used. Above all, when an aluminum oxide sintered body is used, the thermal conductivity of the sintered body itself is 30 W /
It is suitable in terms of high mK.

Thus, according to the above-described package for housing a semiconductor element of the present invention, the semiconductor element 4 is adhered and fixed to the mounting portion on the upper surface of the heat dissipation base 3 via the adhesive 7 made of glass, resin, brazing material or the like. This semiconductor element 4
Each electrode is connected to a predetermined wiring conductor 8 through a bonding wire 5, and then the lid 2 is joined to the upper surface of the insulating frame 1 through a sealing material made of glass, resin, brazing material or the like. By hermetically housing the semiconductor element 4 in the container formed of the insulating frame body 1, the heat dissipation base 3, and the lid body 2,
It becomes a semiconductor device as a product.

[0036]

Example (Example 1) First, the central particle size is several μm to 10 μm.
After mixing an appropriate amount of binder with 0 μm tungsten powder, a pressed body is formed at a pressure of about 1 t / cm ³ , and the pressed formed body is fired at a temperature of about 1500 ° C. Sintered porosity made of tungsten I prepared my body. Next, this porous body is infiltrated by infiltrating 15% by weight of copper at a temperature of 1200 ° C., and the thickness of each of the upper and lower copper layers is 0, 0.015, 0.03.
A heat-dissipating substrate sample for evaluation was prepared so that the thickness was 0, 0.050, 0.10, 0.20, 0.30, 0.50 mm.

With respect to these heat-radiating substrate samples for evaluation, the thermal conductivity (W / W) of the heat-radiating substrate samples for evaluation was measured by the fine ceramics laser flash method specified in JIS R1611 based on the thermal diffusion / specific heat capacity / thermal conductivity test method.
mK) and TMA (Thermomechanical Analy
The thermal expansion coefficient (ppm / ° C) is determined by measuring the elongation of the evaluation heat dissipation substrate sample for each temperature while raising the temperature of the evaluation heat dissipation substrate sample by the (sis) method, and dividing the value by the value of the temperature rise width. Was measured. Further, the joint interface was observed with a microscope having a magnification of 40 times. After that, the same observation was performed with an ultrasonic flaw detector. Regarding the results, Table 1 shows the physical properties of the thermal expansion coefficient and the thermal conductivity of the heat dissipation substrate and the temperature cycle when the thickness ratio of the composite material layer made of tungsten and copper and the copper layers on the upper and lower surfaces thereof was changed. After the test (TCT: -65 / + 150 ℃, 1000 cycles), the bonding interface state between the semiconductor element of 10.0 mm □ and 0.60 mmt made of silicon and the heat dissipation base and the external size are 2
0.0mmt, cavity size is 12.0mm □, thickness is
The joint interface state of an insulating frame of 1.0 mmt and a heat dissipation base is shown.

[0038]

[Table 1]

As can be seen from the results shown in Table 1, No. 1
In No. 8 heat dissipation substrate, the thickness of the composite material layer is 2.0 mm
When the thickness of the copper layer is fixed at t and the thickness of the copper layer is changed from 0 to 0.5 mmt, the composite material layer / copper layer thickness ratio (t2 / t1) is 0.
To 0.25, the thermal conductivity and the coefficient of thermal expansion also show large values. In particular, t2 / t1 = 0.01
A value of 250 W / mK or more was shown at 5 or more. However, although the thermal conductivity does not change significantly when the copper layer thickness is 300 μm or more,
It has been confirmed that when t2 / t1 = 0.15 is exceeded, cracks are generated at the bonding interface between the heat dissipation base and the insulator. As the heat dissipation base, the thickness ratio between the composite material layer and the copper layer, which has a high heat dissipation property of 250 W / mK or more and can secure reliability with the insulator, is:
0.15 or less is suitable.

In No. 9 to No. 10 heat dissipating substrates, the thermal conductivity was 250 even when the thickness of the composite material layer was changed to 1.0 mmt and 3.0 mmt and the thickness of the copper layer was changed to 0.1 and 0.3 mmt.
It can be seen that the coefficient of thermal expansion also shows a value of 8.0 ppm / ° C. or less at W / mK or more.

As for the results when molybdenum was used for the porous body, it was confirmed that, as shown in No. 11, a good thermal conductivity of 250 W / mK or more was exhibited.

(Example 2) Central particle size is several μm to 100 μm
After mixing an appropriate amount of binder with tungsten powder of m,
A pressed body was formed at a pressure of about 1 t / cm ^{3, and} a sintered porous body made of tungsten was prepared by firing the pressed body at a temperature of about 1500 ° C. Next, in this porous body
At a temperature of 1200 ° C, copper was infiltrated by infiltration so that the content of each was 10 to 40% by weight (the amount of tungsten was 90 to 60% by weight), and the thickness of each copper layer on the upper and lower surfaces was 0.
A heat-dissipating substrate sample for evaluation was prepared so as to have a thickness of 10 mm. Then, the same evaluation as in Example 1 was performed. The results are shown in Table 2 in which the amount of copper in the composite material layer with the thickness ratio of the composite material layer and the copper layers on the upper and lower surfaces of 0.05 is 10% by weight to 60% by weight.
Physical properties of thermal expansion coefficient and thermal conductivity of the heat-radiating substrate and temperature cycle test (TCT: -65/150)
The junction interface state between the semiconductor element and the heat dissipation substrate and the junction interface state between the insulator and the heat dissipation substrate after 1000 ° C) are shown.

[0043]

[Table 2]

As can be seen from the results shown in Table 2, No. 1
In No. 6 to No. 6, the copper content of the copper-tungsten composite material layer was changed in the range of 10 to 60% by weight. From now on, the coefficient of thermal expansion gradually increases by increasing the ratio of the amount of copper in the composite material layer. Also, especially the copper ratio is 30% by weight
With the above, the thermal expansion coefficient becomes 9 ppm / ° C. or more, and cracks or the like occur at the interface between the heat dissipation base and the insulator. Therefore, the ratio of copper material in the composite material layer that can ensure reliability is 10 to 25.
Weight percent is preferred.

Further, No. 7 shows the result when molybdenum is used instead of tungsten. From now on 250
It can be seen that good thermal conductivity of W / mK or more is obtained.

The present invention is not limited to the above-mentioned embodiments, and various modifications may be made without departing from the scope of the present invention.

[0047]

According to the package for housing a semiconductor device of the present invention, the heat dissipation base is formed on the composite material layer formed by impregnating a porous body of tungsten or molybdenum with 10 to 25% by weight of copper and the upper and lower surfaces thereof. Porous layer of tungsten or molybdenum, since the thickness of the composite material layer is t1 and the thickness of the copper layer is t2, 30 μm ≦ t2 ≦ 300 μm and t2 ≦ 0.15 × t1. Compared to a heat dissipation substrate composed only of a composite material layer formed by impregnating copper with copper, the heat generated in the semiconductor element mounted on the heat dissipation substrate is first dissipated in the horizontal direction in the plane by the copper layer near the surface. In addition, since the copper layer and the copper in the composite material layer are continuously connected, the heat conduction loss is reduced, and as a result, more heat can be released into the composite material layer. Further, since the inside of the composite material layer is a copper-tungsten material, a thermal conductivity of 200 W / mK or more is secured. As a result, the thermal conductivity of the heat dissipation substrate
It is possible to make it as extremely high as 250 W / mK or more.

Further, the copper layers formed on the upper and lower surfaces of the composite material layer can be formed at the same time when the composite material layer is impregnated with tungsten or molybdenum by the infiltration method. Unlike the copper layer bonded by the rolling method, cracks hardly occur at the interface between the copper layer and the composite material layer due to the thermal stress when the insulating frame is joined to the heat dissipation base, and as a result, the heat dissipation base is It is possible to normally and stably operate the semiconductor element that is placed and accommodated in the package for a long period of time.

Further, the heat dissipation base is composed of a composite material layer formed by impregnating a porous body of tungsten or molybdenum with copper and copper layers formed on the upper and lower surfaces thereof, and the thickness of the composite material layer is t1 and the copper layer is copper. When the layer thickness is t2, 30
Since μm ≦ t2 ≦ 300 μm and t2 ≦ 0.15 × t1, copper having a large coefficient of thermal expansion as well as thermal conductivity occupies a large proportion in the mounting portion of the semiconductor element provided on the upper surface of the heat dissipation base. It is possible to bring the thermal expansion coefficient of the heat dissipation base close to that of the insulating frame.

Particularly, when the composite material layer is formed by impregnating a porous body of tungsten or molybdenum with 10 to 25% by weight of copper, the thermal expansion coefficient of the heat dissipation substrate is 9.0.
Since the value is not more than ppm / ° C., the heat dissipation base and the insulating frame can be bonded to each other favorably and stably over a long period of time.

The insulating frame has a thermal expansion coefficient of 6 to 8 p.
When the ceramics of pm / ° C. (room temperature to 800 ° C.) are used, the thermal expansion coefficient of the heat dissipation base can be set to a value close to the thermal expansion coefficient of the insulating frame.
The heat dissipation base and the insulating frame can be bonded to each other satisfactorily and stably over a long period of time.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an example of an embodiment of a package for housing a semiconductor element of the present invention.

FIG. 2 is a cross-sectional view showing a schematic configuration of a heat dissipation base in the semiconductor element housing package of the present invention.

FIG. 3 is a cross-sectional view showing an example of a conventional semiconductor element housing package.

[Explanation of symbols]

1 ... Insulation frame 2 ... Lid 3 ... Heat dissipation base 3a ... Composite material layer 3b ... Copper layer 4 ... Semiconductor element

Claims (3)

[Claims] 1. A heat dissipation base having a mounting part on which a semiconductor element is mounted, an insulating frame body attached to the upper surface of the heat dissipation base so as to surround the mounting part, and the insulating frame. A package for accommodating a semiconductor device, comprising a lid attached to the upper surface of the body, wherein the heat dissipation base is formed on a composite material layer formed by impregnating a porous body of tungsten or molybdenum with copper and the upper and lower surfaces thereof. 30 μm ≦ t2 ≦ 300 μm and t2 ≦ 0.15 ×, where the composite material layer has a thickness of t1 and the copper layer has a thickness of t2.
A package for housing a semiconductor element, which is t1. 2. The package for accommodating a semiconductor element according to claim 1, wherein the composite material layer is formed by impregnating a porous body of tungsten or molybdenum with 10 to 25% by weight of copper. 3. The insulating frame has a coefficient of thermal expansion of 6 to 8
2. The package for housing a semiconductor element according to claim 1, which is made of a ceramic having a ppm / ° C. (room temperature to 800 ° C.).