JP2000138332A - Package for storing semiconductor elements - Google Patents

Abstract

(57) [Problem] To produce a crack or a crack in a frame-shaped insulator due to a difference in thermal expansion coefficient between a heat sink and a frame-shaped insulator. Cannot be operated normally and stably for a long time. A mounting section on which a semiconductor element is mounted on an upper surface.
a semiconductor device housing package in which a frame-shaped insulator 2 is attached to a heat radiating plate 1 surrounding the mounting portion 1a, wherein the heat radiating plate 1 is made of carbon fibers arranged in a thickness direction. A metal layer 6 having a three-layer structure of a chromium-iron alloy layer 6a, a copper layer 6b, and a molybdenum layer 6c is formed on both upper and lower surfaces of a core 1b made of a unidirectional composite material in which carbon is bonded by carbon by diffusion bonding. And the thicknesses of the chromium-iron alloy layer 6a, the copper layer 6b, and the molybdenum layer 6c are substantially the same.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device housing package for housing a semiconductor device such as an LSI (Large Scale Integrated Circuit).

[0002]

2. Description of the Related Art Conventionally, a semiconductor element housing package for housing a semiconductor element has a heat sink made of a metal material such as copper or copper-tungsten alloy having a mounting portion on which the semiconductor element is mounted. A frame-shaped insulator made of an electrically insulating material such as an aluminum oxide sintered body attached to the upper surface of the heat sink so as to surround the mounting portion, and an inner peripheral portion of the frame-shaped insulator; A plurality of metallized wiring layers made of a refractory metal powder such as tungsten, molybdenum, and manganese, which are adhered to the outer peripheral portion, and a lid that is attached to an upper surface of the frame-shaped insulator and closes a hole in the insulator. The semiconductor element is bonded and fixed to the semiconductor element mounting portion of the heat sink via an adhesive such as glass, resin, brazing material, etc., and each electrode of the semiconductor element is framed via a bonding wire. Like insulator Electrically connected to the formed metallized wiring layer, and thereafter, the lid is joined to the frame-shaped insulator via a sealing material made of glass, resin, brazing material or the like so as to cover the hole of the insulator. A semiconductor device as a product is obtained by hermetically housing a semiconductor element inside a container including a heat sink, a frame-shaped insulator, and a lid.

In the above-described semiconductor device housing package, the heat sink on which the semiconductor device is mounted is formed of a metal material such as copper or a copper-tungsten alloy. Because of its excellent thermal conductivity, the radiator plate can absorb heat generated during operation of the semiconductor device well and radiate it well into the atmosphere.
As a result, the semiconductor element is always kept at an appropriate temperature, thereby effectively preventing the semiconductor element from being thermally degraded and the characteristics from being thermally degraded.

[0004]

However, in this conventional package for housing a semiconductor element, when the heat radiating plate is made of copper, the copper has a thermal expansion coefficient of about 18 × 1.
The thermal expansion coefficient of the aluminum oxide sintered body or the like constituting a frame-shaped insulator at 0 ^-6 / ° C (the coefficient of thermal expansion of the aluminum oxide sintered body is about 7 × 10 ^-6 / ° C) is greatly different. Therefore, after the semiconductor element is hermetically accommodated in the container and formed into a semiconductor device, when heat or the like generated when the semiconductor element is operated is applied to each of the frame-shaped insulator and the heat sink, the heat sink and the frame Thermal stress occurs due to the difference in the coefficient of thermal expansion between them and the frame-shaped insulator, and the heat stress causes the radiator plate to be peeled off from the frame-shaped insulator and cracks or cracks to be generated in the frame-shaped insulator As a result, the hermetic sealing of the container is broken, and the semiconductor element housed in the container cannot be operated normally and stably for a long period of time.

When the heat sink is made of a copper-tungsten alloy, the copper-tungsten alloy is heavy, so that the semiconductor element is hermetically accommodated in a container, and when the semiconductor device is formed, the weight of the semiconductor device is reduced. Electronic devices that are becoming heavier and smaller and lighter in recent years have had a disadvantage that their mounting becomes difficult.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned drawbacks, and has as its object to complete the hermetic sealing of the inside of a container and to keep the semiconductor device housed inside the container always at an appropriate temperature so that the semiconductor device can operate normally for a long period of time. Another object of the present invention is to provide a semiconductor device housing package that can be operated stably.

[0007]

According to the present invention, a frame-shaped insulator is attached to a heat sink having a mounting portion on which a semiconductor element is mounted on the upper surface so as to surround the mounting portion. In a semiconductor device storage package, the radiator plate includes a chromium-iron alloy layer, a copper layer, and a molybdenum layer on both upper and lower surfaces of a core made of a unidirectional composite material in which carbon fibers arranged in a thickness direction are bonded with carbon. A metal layer having a layer structure is formed by being applied by diffusion bonding, and the chromium-iron alloy layer,
The thickness of each of the copper layer and the molybdenum layer is substantially the same.

According to the semiconductor device housing package of the present invention, a chromium-iron alloy layer and a copper layer are formed on both upper and lower surfaces of a core made of a unidirectional composite material in which carbon fibers arranged in the thickness direction are bonded with carbon as a heat sink. Since a metal layer having a three-layer structure of a molybdenum layer is used by diffusion bonding, heat generated during operation of the semiconductor element is selectively transmitted from the upper surface side to the lower surface side of the heat radiating plate, and the heat of the heat radiating plate is reduced. The semiconductor element is efficiently radiated from the lower surface to the atmosphere, and as a result, the semiconductor element always has an appropriate temperature, and the semiconductor element can be operated normally and stably for a long period of time.

According to the package for accommodating a semiconductor element of the present invention, a chromium-iron alloy layer, a copper layer, a molybdenum layer are formed on both upper and lower surfaces of a core made of a unidirectional composite material in which carbon fibers arranged in a thickness direction are bonded with carbon. The radiator plate formed by diffusion bonding of a metal layer having a three-layer structure has a thermal expansion coefficient of about 7 × 1.
0 ⁻⁶ / ° C., which is close to the coefficient of thermal expansion of an aluminum oxide sintered body or the like forming a frame-shaped insulator. Even if heat generated during operation of the semiconductor element is applied to each of the heat sink and the frame insulator, a large thermal stress is generated between the heat sink and the frame insulator due to a difference in thermal expansion coefficient between the heat sink and the frame insulator. As a result, the heat sink can be firmly joined to the insulator without causing cracks or cracks in the insulator, and the heat generated during operation of the semiconductor element can be radiated well into the atmosphere. In addition, the semiconductor element housed in the container can be normally and stably operated for a long period of time.

According to the package for accommodating a semiconductor element of the present invention, a chromium-iron alloy layer, a copper layer, and a molybdenum layer are formed on both upper and lower surfaces of a core made of a unidirectional composite material in which carbon fibers arranged in the thickness direction are bonded with carbon. The heat sink, which is formed by diffusion bonding of a metal layer having a three-layer structure, is about 1/5 the weight of a copper-tungsten alloy and is extremely light. In the case where a semiconductor device is accommodated in an element, the weight of the semiconductor device is extremely reduced. As a result, the semiconductor device can be mounted on an electronic device whose size and weight have been reduced recently.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described in detail with reference to the accompanying drawings. 1 and 2 show an embodiment of a package for accommodating a semiconductor element according to the present invention, wherein 1 is a heat sink, 2 is a frame-shaped insulator, and 3 is a lid. The heat sink 1, the frame-shaped insulator 2, and the lid 3 constitute a container 5 for housing the semiconductor element 4.

The heat radiating plate 1 has a mounting portion 1a on the upper surface of which the semiconductor element 4 is mounted, and a mounting portion on the outer peripheral portion of the upper surface where the semiconductor element 4 provided on the upper surface of the heat radiating plate 1 is mounted. A frame-shaped insulator 2 is attached via an adhesive such as a brazing material, glass, or resin so as to surround 1a.

The heat radiating plate 1 functions as a support member for supporting the semiconductor element 4 and also absorbs heat generated when the semiconductor element 4 is operated well and efficiently dissipates it into the atmosphere to keep the semiconductor element 4 always at an appropriate temperature. The semiconductor element 4 is fixed on the mounting portion 1a of the heat sink 1 surrounded by the frame-shaped insulator 2 via an adhesive such as glass, resin, brazing material or the like.

As shown in FIG. 2, the radiator plate 1 has a chromium-iron alloy layer 6 on both upper and lower surfaces of a core 1b made of a unidirectional composite material in which carbon fibers arranged in the thickness direction are bonded with carbon.
a, a metal layer 6 having a three-layer structure of a copper layer 6b and a molybdenum layer 6c, which is applied by diffusion bonding, and a high melting point metal powder of tungsten, molybdenum, manganese, etc. A metallized metal layer 7 made of, for example, is adhered to the metallized metal layer 7, and the metal layer 6 adhered to the upper surface side of the heat dissipation slope 1 is soldered to a brazing material such as solder, silver-copper alloy, or titanium-silver-copper alloy. The heat radiating plate 1 is attached to the lower surface of the frame-shaped insulator 2 by brazing.

The core 1b made of the unidirectional composite material of the heat sink 1 is made of, for example, a bundle of carbon fibers arranged in one direction, such as a solid pitch or a phenol resin in which fine powder such as coke is dispersed. Impregnated in a solution of thermosetting resin, and then dried to form a plurality of sheets in which carbon fibers are arranged in one direction and the direction of the carbon fibers in each sheet is the same. In this way, a plurality of sheets are laminated, and then a predetermined pressure is applied to the plurality of laminated sheets and heated to cure the thermosetting resin portion,
Finally, this is fired at a high temperature in an inert atmosphere to carbonize the phenolic resin and the fine powder of pitch or coke (form carbon) and bond each carbon fiber with the carbon.

The core 1b made of the unidirectional composite material of the heat sink 1 has a metal layer 6 consisting of three layers of a chromium-iron alloy layer 6a, a copper layer 6b, and a molybdenum layer 6c on both upper and lower surfaces. The chromium-iron alloy layer 6a, the copper layer 6b, and the molybdenum layer 6c of the metal layer 6 have substantially the same thickness.

The metal layer 6 is formed of three layers of a chromium-iron alloy layer 6a, a copper layer 6b, and a molybdenum layer 6c having substantially the same thickness because the coefficient of thermal expansion of the core 1b made of a unidirectional composite material is limited. Approx. 7 × 10 approximating the thermal expansion coefficient of the insulator 2
^-6 / ° C., and a chromium-iron alloy layer 6a having substantially the same thickness on both upper and lower surfaces of a core 1b made of a unidirectional composite material.
Radiator plate 1 on which a metal layer 6 composed of three layers, namely, a copper layer 6b and a molybdenum layer 6c, has a thermal expansion coefficient of about 7 × 1.
0 ^-6 / ° C.
Even if heat or the like generated during operation of the semiconductor element 4 is applied to both of them after being attached to the lower surface of the heat sink, the difference in thermal expansion coefficient between the heat radiating plate 1 and the frame-shaped insulator 2 exists between them. No large thermal stress is generated due to the
Is firmly bonded to the frame-shaped insulator 2 and enables the heat generated during the operation of the semiconductor element 4 to be satisfactorily dissipated into the atmosphere. It can be operated stably.

The metal layer 6 is applied by diffusion bonding to the upper and lower surfaces of a core 1b made of a unidirectional composite material. Specifically, the core 1b made of a unidirectional composite material is provided. A chromium-iron alloy foil, a copper foil, and a molybdenum foil each having a thickness of 50 μm or less are sequentially placed on the upper and lower surfaces, and then a temperature of 12000 c is applied for 1 hour while applying a pressure of 5 MPa by a vacuum hot press. It is done by doing.

The chromium-iron alloy layer 6a of the metal layer 6
Has a function of firmly joining the metal layer 6 to the core 1b made of the unidirectional composite material, and the copper layer 6b firmly joins the chromium-iron alloy layer 6a and the molybdenum layer 6c, and interdiffusion therebetween. And the molybdenum layer 6c has a chromium-iron alloy layer 6a and a copper layer 6c.
b, the thermal expansion coefficient of the heat sink 1 is about 7 × 10 ⁻⁶ / ° C.
It works.

The heat radiating plate 1 in which the metal layers 6 are adhered to the upper and lower main surfaces of the core 1b made of the unidirectional composite material is provided in the direction of the carbon fibers of the core 1b made of the unidirectional composite material. That is, the thermal conductivity in the direction from the upper surface to the lower surface of the heat sink 1 is 300 W / m · k or more, and the thermal conductivity in the direction perpendicular to the carbon fiber is 30 W / m · k or less. Heat is selectively and efficiently transmitted in one direction from the side toward the lower surface. Therefore, when the semiconductor element 4 is mounted and fixed on the upper surface of the radiator plate 1 using the core 1b made of the unidirectional composite material, the heat generated when the semiconductor element 4 is operated is reduced from the upper surface of the radiator plate 1 to the lower surface. Direction, and is efficiently radiated from the lower surface of the heat sink 1 into the atmosphere.

The heat radiating plate 1 using the core 1b made of the unidirectional composite material is about 1/5 of the weight of the copper-tungsten alloy and is light. When a semiconductor device is formed by housing the semiconductor element 4 in a package for housing a semiconductor element, the weight of the semiconductor device is extremely reduced, and it is possible to mount the semiconductor device on electronic devices, which have recently become smaller and lighter. Become.

Further, a core 1 made of the unidirectional composite material
The heat radiating plate 1 using b has an elastic modulus of 30 GPa or less and is soft. Therefore, even if there is a slight difference in the coefficient of thermal expansion between the heat radiating plate 1 and the frame-shaped insulator 2, the heat radiating plate 1 is generated between them. The heat stress generated is absorbed by appropriately deforming the heat sink 1, and as a result, the frame-shaped insulator 2 and the heat sink 1 are bonded very firmly, and the heat generated by the semiconductor element 4 is always efficiently discharged into the atmosphere. Can be dissipated.

Further, the heat radiating plate 1 in which the metal layers 6 are applied to the upper and lower surfaces of the core 1b made of the unidirectional composite material,
A thermal stress is generated between the core 1b and the upper metal layer 6 and between the core 1b and the lower metal layer 6 due to a difference in thermal expansion coefficient between the two. The positions of attachment to the core 1b are different from each other because they are different from each other. As a result, the heat radiating plate 1 is not deformed by the thermal stress generated between the core 1b and the metal layer 6 and is always flat. The heat radiating plate 1 can be firmly bonded to the lower surface of the insulator 2, and the heat generated when the semiconductor element 4 is operated can be efficiently radiated into the atmosphere via the heat radiating plate 1.

Further, a frame-shaped insulator 2 is formed on the outer peripheral portion of the upper surface of the heat sink 1 so as to surround the mounting portion 1a on which the semiconductor element 4 provided on the upper surface of the heat sink 1 is mounted. The heatsink 1 and the frame-shaped insulator 2 form a space for accommodating the semiconductor element 4 therein.

The frame-shaped insulator 2 attached to the heat sink 1 is made of an electrically insulating material such as an aluminum oxide sintered body.
For example, an appropriate organic binder, a solvent, and the like are added to and mixed with raw material powders such as aluminum oxide, silicon oxide, magnesium oxide, and calcium oxide to form a slurry, and the slurry is subjected to a doctor blade method or a calendar roll method. In this way, a ceramic green sheet (ceramic green sheet) is formed. Thereafter, the ceramic green sheet is subjected to an appropriate punching process, and a plurality of the green sheets are laminated and fired at a temperature of about 1600 ° C.

The frame-shaped insulator 2 is further formed with a plurality of metallized wiring layers 8 extending from the inner peripheral portion to the upper surface thereof, and is exposed on the inner peripheral portion of the frame-shaped insulator 2. Each electrode of the semiconductor element 4 is electrically connected to one end of the semiconductor element 4 via a bonding wire 9, and an external lead pin 10 connected to an external electric circuit is provided at a portion led out on the upper surface of the frame-shaped insulator 2. It is brazed and attached via a brazing material such as silver brazing.

The metallized wiring layer 8 functions as a conductive path when connecting each electrode of the semiconductor element 4 to an external electric circuit, and is formed of a high melting point metal powder such as tungsten, molybdenum, and manganese.

The metallized wiring layer 8 is made of tungsten,
A metal paste obtained by adding and mixing an appropriate organic binder, a solvent, and the like to a high melting point metal powder such as molybdenum and manganese is formed into a predetermined pattern on a ceramic green sheet serving as a frame-shaped insulator 2 in advance by a conventionally well-known screen printing method. By printing and applying, the frame-shaped insulator 2 is adhered and formed from the inner peripheral portion to the upper surface.

The metallized wiring layer 8 is formed by coating a metal having excellent corrosion resistance such as nickel and gold and having excellent wettability with a brazing material to a thickness of 1 μm to 20 μm on an exposed surface by plating. By doing so, oxidation corrosion of the metallized wiring layer 8 can be effectively prevented, and the brazing of the external lead pins 10 to the metallized wiring layer 8 can be made firm. Therefore, the metallized wiring layer 8
Is a metal having excellent corrosion resistance, such as nickel and gold, having excellent wettability with a brazing material on the exposed surface of 1 μm to 20 μm.
It is preferable that it is applied to a thickness of μm.

External lead pins 10 are brazed to the metallized wiring layer 8 via a brazing material such as silver brazing. The external lead pins 10 connect each electrode of the semiconductor element 4 housed in the container 5. The semiconductor element 4 accommodated in the container 5 by connecting the external lead pin 10 to the external electric circuit is connected to the external electric circuit via the metallized wiring layer 8 and the external lead pin 10. Will be connected.

The external lead pin 10 is made of a metal material such as an iron-nickel-cobalt alloy or an iron-nickel alloy. For example, an ingot made of a metal such as an iron-nickel-cobalt alloy is rolled or stamped. For example, it is formed into a predetermined shape by performing a conventionally known metal working method.

Thus, according to the above-described semiconductor element housing package, the semiconductor element 4 is bonded and fixed on the semiconductor element mounting portion 1a of the heat sink 1 via an adhesive such as glass, resin, brazing material or the like. Each electrode of the element 4 is connected to a predetermined metallized wiring layer 8 via a bonding wire 9, and thereafter, a lid 3 is formed on the upper surface of the frame-shaped insulator 2 by a sealing material made of glass, resin, brazing material, or the like. The semiconductor device 4 is hermetically accommodated in a container 5 including a heat sink 1, a frame-shaped insulator 2, and a lid 3 to form a semiconductor device as a product.

The present invention is not limited to the above-described embodiment, and various changes can be made without departing from the scope of the present invention.

[0034]

According to the semiconductor device housing package of the present invention, a chromium-iron alloy layer is provided on both upper and lower surfaces of a core made of a unidirectional composite material in which carbon fibers arranged in the thickness direction are bonded by carbon as a heat sink. Since a metal layer having a three-layer structure of a copper layer and a molybdenum layer is used by diffusion bonding, heat generated during operation of the semiconductor element is selectively transmitted from the upper surface side to the lower surface side of the heat sink and dissipated. The semiconductor device is efficiently radiated from the lower surface side of the plate into the atmosphere, and as a result, the semiconductor device always has an appropriate temperature, and the semiconductor device can be operated normally and stably for a long period of time.

According to the package for accommodating a semiconductor element of the present invention, a chromium-iron alloy layer, a copper layer, a molybdenum layer are formed on both upper and lower surfaces of a core made of a unidirectional composite material in which carbon fibers arranged in the thickness direction are bonded with carbon. The radiator plate formed by diffusion bonding of a metal layer having a three-layer structure has a thermal expansion coefficient of about 7 × 1.
0 ⁻⁶ / ° C., which is close to the coefficient of thermal expansion of an aluminum oxide sintered body or the like forming a frame-shaped insulator. Even if the thermal expansion coefficient generated during operation of the semiconductor element is applied to each of the heat sink and the frame-shaped insulator, a large thermal stress is caused between the heatsink and the frame-shaped insulator due to a difference between the two. As a result, the heat sink is firmly bonded to the insulator without causing cracks or cracks in the insulator, and it is necessary to dissipate the heat generated during operation of the semiconductor element well into the atmosphere. If possible, the semiconductor element housed in the container can be operated normally and stably for a long period of time.

According to the package for accommodating a semiconductor element of the present invention, a chromium-iron alloy layer, a copper layer, a molybdenum layer are formed on both upper and lower surfaces of a core made of a unidirectional composite material in which carbon fibers arranged in a thickness direction are bonded with carbon. The heat sink, which is formed by diffusion bonding of a metal layer having a three-layer structure, is about 1/5 the weight of a copper-tungsten alloy and is extremely light. In the case where a semiconductor device is accommodated in an element, the weight of the semiconductor device is extremely reduced. As a result, the semiconductor device can be mounted on an electronic device whose size and weight have been reduced recently.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing one embodiment of a semiconductor element storage package according to the present invention.

2 is an enlarged cross-sectional view of a main part of the package for housing a semiconductor element shown in FIG. 1;

[Explanation of symbols]

 1 ... Heat sink 1a ... Mounting portion of semiconductor element 1b ... Core 2 ... Frame-shaped insulator 3 ·························· Semiconductor device 6 ······· Metal layer 6a ······ Chromium-iron alloy layer 6b ······ ··· Copper layer 6c ······ Molybdenum layer 8 ······ Metallized wiring layer 10 ······· External lead pins

Claims (1)

[Claims] 1. A semiconductor element storage package comprising a heat sink having a mounting portion on which a semiconductor element is mounted on an upper surface, and a frame-shaped insulator attached to the heat sink so as to surround the mounting portion. The radiator plate has a three-layer structure of a chromium-iron alloy layer, a copper layer, and a molybdenum layer diffused on both upper and lower surfaces of a core made of a unidirectional composite material in which carbon fibers arranged in the thickness direction are bonded with carbon. It is formed by being bonded by joining,
A package for accommodating a semiconductor element, wherein each of the chromium-iron alloy layer, the copper layer and the molybdenum layer has substantially the same thickness.