JP3748399B2 - Package for storing semiconductor elements - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a semiconductor element housing package for housing semiconductor elements such as LSIs (Large Scale Integrated Circuit Elements) and optical semiconductor elements.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, a package for housing a semiconductor element for housing a semiconductor element includes a base made of a metal material such as a copper-tungsten alloy or a copper-molybdenum alloy having a placement portion on which the semiconductor element is placed, and the base. A frame-like insulator made of an electrically insulating material such as an aluminum oxide sintered body attached so as to surround the mounting portion on the upper surface of the frame, and a covering from the inner peripheral portion to the outer peripheral portion of the frame-like insulator. A plurality of wiring layers made of refractory metals such as tungsten, molybdenum, and manganese, and a lid that is attached to the upper surface of the frame-like insulator and closes a hole inside the insulator. The semiconductor element is bonded and fixed to the semiconductor element mounting portion of the base via an adhesive, and each electrode of the semiconductor element is electrically connected to a wiring layer formed on the frame-like insulator via a bonding wire. Sir The base body, the frame-like insulator, and the lid body are joined to the frame-like insulator through a sealing material made of glass, resin, brazing material or the like so as to close the hole inside the frame-like insulator. A semiconductor device as a product is obtained by airtightly housing a semiconductor element in a container formed of
[0003]
In the semiconductor element storage package described above, the base on which the semiconductor element is placed is formed of a metal material such as a copper-tungsten alloy or a copper-molybdenum alloy, and the copper-tungsten alloy, copper-molybdenum alloy, or the like. Has a high thermal conductivity of about 180 W / m · K and is excellent in thermal conductivity, so that the substrate can absorb the heat generated during the operation of the semiconductor element and dissipate it well into the atmosphere. The semiconductor element is always kept at an appropriate temperature, and it is possible to effectively prevent the semiconductor element from being thermally destroyed and the characteristics from being thermally deteriorated.
[0004]
The copper-tungsten alloy or copper-molybdenum alloy used as the base of the above-mentioned package for housing semiconductor elements is obtained by firing tungsten powder or molybdenum powder to obtain a sintered porous body, and then emptying the sintered porous body. For example, when impregnating copper into a sintered porous body made of tungsten, the sintered porous body is in the range of 75 to 90% by weight and copper is in the range of 10 to 25% by weight. When the sintered porous body made of molybdenum is impregnated with copper, the sintered porous body is in the range of 80 to 90% by weight and copper is in the range of 10 to 20% by weight.
[0005]
[Problems to be solved by the invention]
However, in this conventional package for housing semiconductor elements, the substrate is obtained by firing a tungsten powder or molybdenum powder to obtain a sintered porous body, and impregnating the molten copper into the pores of the sintered porous body. As the amount of copper is increased, the thermal conductivity of the substrate increases, but the linear thermal expansion coefficient of the substrate increases accordingly. The substrate is greatly different from the linear thermal expansion coefficient (7 ppm / ° C .: room temperature to 800 ° C.) of the frame-like insulator made of the aluminum oxide sintered body attached to the upper surface. The generated stress acts on the joint interface between the two, and the stress causes cracks in the joint interface or, if it is severe, peeling occurs on the joint interface between the two. Since the reliability is impaired and the problem that the semiconductor element accommodated in the semiconductor device cannot be operated normally with high reliability occurs, the linear thermal expansion coefficient of the base body is the wire of the frame-like insulator. It is necessary to approximate the thermal expansion coefficient, and the copper content of the base is 10 to 25% by weight (if the base is made of a copper-tungsten alloy, the copper content is 10 to 25% by weight, copper-molybdenum If made of gold content in copper will be limited to a range of 10 to 20 wt%), the thermal conductivity of the base was about 180 W / m · K at most.
[0006]
For this reason, in the conventional package for storing semiconductor elements, the recent increase in density and integration has greatly progressed, and when semiconductor elements that generate a large amount of heat during operation are accommodated, the heat generated during operation of the semiconductor elements passes through the substrate. As a result, the semiconductor element becomes high temperature due to the heat generated by the element itself, resulting in thermal destruction of the semiconductor element or variation in characteristics, which makes it impossible to operate stably. Had the disadvantages.
[0007]
Further, in this conventional package for housing semiconductor elements, since the relative permittivity of the aluminum oxide sintered body forming the frame-like insulator is as high as 9 to 10 (room temperature, 1 MHz), the wiring provided on the frame-like insulator The propagation speed of the electric signal transmitted through the layers is slow, so that a semiconductor element that requires high-speed signal propagation has the disadvantage that it cannot be accommodated.
[0008]
Further, in this conventional package for housing semiconductor elements, the wiring layer formed on the frame-like insulator is formed of a refractory metal material such as tungsten, molybdenum, manganese, etc., which has a specific electric resistance. Since the electrical signal is propagated to the wiring layer due to its high value of 5.4 μΩ · cm (20 ° C.) or more, there is a disadvantage that the electrical signal is greatly attenuated and the electrical signal cannot be propagated accurately and reliably. Was.
[0009]
The present invention has been devised in view of the above drawbacks, and its purpose is to accommodate a semiconductor element that can be driven at a high speed inside, and to operate the accommodated semiconductor element normally and stably over a long period of time. An object of the present invention is to provide a package for housing a semiconductor element.
[0010]
[Means for Solving the Problems]
The present invention provides a base having a mounting portion on which a semiconductor element is mounted on an upper surface, and a wiring that is attached on the base so as to surround the semiconductor element mounting portion and to which each electrode of the semiconductor element is connected A package for housing a semiconductor element, comprising: a frame-like insulator having a layer; and a lid attached on the frame-like insulator and hermetically sealing an inner side of the frame-like insulator, body relative dielectric constant of 7 or less, the thermal expansion coefficient of a glass ceramic sintered body of 4ppm / ℃ ~8ppm / ℃, the wiring layer is electrical resistivity in 2.5μΩ · cm (20 ℃) following metallic materials the substrate is a 65 to 95 wt% of silicon carbide is formed by a 5 to 35 wt% of copper, der Rukoto which silicon carbide powder is formed by dispersedly mixed in the molten copper It is a feature.
[0011]
According to the package for housing a semiconductor element of the present invention, since the frame-like insulator is formed of a glass ceramic sintered body having a relative dielectric constant of 7 or less, the propagation speed of the electric signal transmitted through the wiring layer provided on the frame-like insulator. Therefore, it is possible to accommodate a semiconductor element that requires high-speed signal propagation.
[0012]
Further, according to the package for housing a semiconductor element of the present invention, the frame-shaped insulator is formed of a glass ceramic sintered body capable of low-temperature firing (about 800 ° C. to 900 ° C.). The wiring layer can be formed of copper, silver, or gold having a specific electric resistance of 2.5 μΩ · cm (20 ° C.) or less, and as a result, when an electric signal is propagated to the wiring layer, Large attenuation does not occur, and the electric signal can be propagated accurately and reliably.
[0013]
Further, according to the package for housing a semiconductor element of the present invention, the substrate is formed of 65 to 95% by weight of silicon carbide and 5 to 35% by weight of copper, and has a high thermal conductivity of 230 W / m · K or more. Therefore, even if the semiconductor element mounted on the base generates a large amount of heat during operation, the heat spreads quickly in the plane direction of the semiconductor element mounting portion of the base and propagates well in the thickness direction of the base. Thus, the semiconductor element can be efficiently and reliably dissipated to the outside, whereby the semiconductor element always has an appropriate temperature, and the semiconductor element can be stably and normally operated over a long period of time.
[0014]
Furthermore, according to the package for housing a semiconductor element of the present invention, the substrate is formed of 65 to 95% by weight of silicon carbide and 5 to 35% by weight of copper, and the linear thermal expansion coefficient is determined from the glass ceramic sintered body. The linear thermal expansion coefficient ( 4 ppm / ° C. to 8 ppm / ° C .: room temperature to 800 ° C.) of the frame-shaped insulator is obtained. Even when heat is applied to both the base and the frame insulator during operation, a large thermal stress is generated between the base and the frame insulator due to the difference in linear thermal expansion coefficient between the two. As a result, the hermetic sealing of the space for housing the semiconductor element is always complete, and the semiconductor element can be operated stably and normally.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Next, the present invention will be described in detail based on embodiments shown in the accompanying drawings.
FIG. 1 is a cross-sectional view showing an embodiment of a package for housing a semiconductor element of the present invention. In FIG. 1, 1 is a base, 2 is a frame insulator, and 3 is a lid. The base body 1, the frame-like insulator 2, and the lid body 3 constitute a container 5 that contains the semiconductor element 4 in an airtight manner.
[0016]
The base body 1 has a mounting portion 1a on which the semiconductor element 4 is mounted, and surrounds the mounting portion 1a on which the semiconductor element 4 provided on the upper surface of the base body 1 is mounted on the outer periphery of the upper surface. Thus, the frame-like insulator 2 is attached via an adhesive such as brazing material, glass, or resin.
[0017]
The base body 1 acts as a support member for supporting the semiconductor element 4 and absorbs heat generated when the semiconductor element 4 is activated, efficiently dissipates it into the atmosphere, and makes the semiconductor element 4 always have an appropriate temperature. The semiconductor element 4 is fixed on the mounting portion 1a of the base body 1 surrounded by the frame-like insulator 2 through an adhesive such as glass, resin, or brazing material.
[0018]
Note the substrate 1 is composed of a silicon carbide and copper, are manufactured work by the fact of dispersing mixing silicon carbide powder having an average particle diameter of 5μm to copper is molten.
[0019]
The frame-like insulator 2 is made of brazing material, glass, resin or the like so as to surround the mounting portion 1a on which the semiconductor element 4 provided on the upper surface of the substrate 1 is mounted on the outer periphery of the upper surface of the substrate 1. A space for accommodating the semiconductor element 4 is formed in the base 1 and the frame-like insulator 2 by being attached via an adhesive.
[0020]
The frame-like insulator 2 attached to the substrate 1 is composed of a glass ceramic sintered body (linear thermal expansion coefficient: 4 ppm / ° C. to 8 ppm / ° C.) having a relative dielectric constant of 7 or less.
1) Glass ceramics sintered body (relative dielectric constant 5-6) manufactured from raw material powder made by adding alumina or mullite to borosilicate glass
2) Glass ceramics sintered body (relative dielectric constant 5-6) manufactured from raw material powder made by adding alumina or mullite to cordierite crystallized glass
3) Sintered glass ceramics (relative dielectric constant 5-6) manufactured from raw material powder made by adding alumina or mullite to mullite crystallized glass
Etc. are formed.
[0021]
For example, when the frame-like insulator 2 is made of a glass ceramic sintered body manufactured from a raw material powder obtained by adding alumina or mullite to borosilicate glass, the composition of the raw material powder is 72 to 76% by weight. Total amount of silica, 15-17% boron oxide, 2-4% aluminum oxide, 1.5% or less magnesium oxide, 1.1-1.4% zirconium oxide, sodium oxide, potassium oxide and lithium oxide A borosilicate glass powder composed of 2.0 to 3.0% is added with a binder, a dispersant, a plasticizer, and an organic solvent mainly composed of alumina or mullite powder and an acrylic resin to form a slurry. By adopting a doctor blade method or a calendar roll method, a green sheet (raw sheet) is formed, and then suitable for the green sheet. This laminating a plurality together subjected to blanking Chi is fabricated by firing at a temperature of about 800 ° C. to 900 ° C..
[0022]
The frame-like insulator 2 has a plurality of wiring layers 6 led out from the inner periphery to the upper portion thereof, and is attached to one end of the wiring layer 6 exposed at the inner periphery of the frame-like insulator 2. Each electrode of the element 4 is electrically connected via a bonding wire 7, and an external lead pin 8 connected to an external electric circuit is connected to an external electric circuit at a portion led out to the upper surface of the frame-like insulator 2. It is attached by brazing.
[0023]
The wiring layer 6 functions as a conductive path for connecting each electrode of the semiconductor element 4 to an external electric circuit, and is formed of a metal powder such as copper, silver, or gold.
[0024]
The wiring layer 6 is formed by adding a metal paste obtained by adding and mixing an appropriate organic binder, a solvent, etc. to a metal powder such as copper, silver, gold or the like on a green sheet to be the frame-like insulator 2 in advance. By using a printing method such as the above, a predetermined pattern is printed and applied, so that the frame-shaped insulator 2 is deposited from the inner periphery to the upper surface.
[0025]
Although the melting point of copper, silver, gold, etc. forming the wiring layer 6 is as low as about 1000 ° C., the sintering temperature of the glass-ceramic sintered body constituting the frame-shaped insulator 2 is low. It is possible to deposit and form a pattern.
[0026]
Copper, silver, gold or the like forming the wiring layer 6 has a low specific electric resistance of 2.5 μΩ · cm or less, so that the semiconductor element 4 accommodated inside the container via the wiring layer 6 and the external electric circuit Even if an electric signal is taken in and out in the meantime, the electric signal is not greatly attenuated in the wiring layer 6, and as a result, the semiconductor element 4 can be driven accurately and reliably.
[0027]
Furthermore, the wiring layer 6 has a low dielectric constant of 7 or less (room temperature, 1 MHz), preferably 5.5 to 6, since the frame-like insulator 2 to which the wiring layer 6 is applied is low. As a result, even if an electric signal is taken in and out between the semiconductor element 4 accommodated in the container and the external electric circuit via the wiring layer 6, the electric signal is propagated. Thus, an electrical signal can be input / output accurately and reliably to / from the semiconductor element 4 without causing any delay.
[0028]
When the wiring layer 6 is made of copper or silver, it is possible to effectively prevent oxidation corrosion of the wiring layer 6 by depositing a metal having excellent corrosion resistance on the exposed surface to a thickness of 1 μm to 20 μm by plating. In addition, the connection between the wiring layer 6 and the bonding wire 7 and the attachment of the external lead pin 8 to the wiring layer 6 can be strengthened. Therefore, when the wiring layer 6 is made of copper or silver, the wiring layer 6 is exposed in order to prevent oxidative corrosion of the wiring layer 6 and to firmly attach the wiring layer 6 to the bonding wire 7 and the external lead pin 8. It is preferable to deposit a metal having excellent corrosion resistance such as gold on the surface to a thickness of 1 μm to 20 μm.
[0029]
The external lead pins 8 brazed to the wiring layer 6 attached to the frame-like insulator 2 are made of a metal material such as iron-nickel-cobalt alloy or iron-nickel alloy, and each electrode of the semiconductor element 4 is connected to the external electric power. Electrically connects to the circuit.
[0030]
The external lead pin 8 is formed in a predetermined shape by subjecting an ingot made of a metal such as iron-nickel-cobalt alloy to a conventionally known metal processing method such as a rolling method or a punching method.
[0031]
In the package for housing a semiconductor element of the present invention, it is important that the substrate 1 is formed of 65 to 95% by weight of silicon carbide and 5 to 35% by weight of copper.
[0032]
If the substrate 1 is formed of 65 to 95% by weight of silicon carbide and 5 to 35% by weight of copper, the substrate 1 has a high thermal conductivity of 230 W / m · K or more. Even if the semiconductor element 4 placed on 1 generates a large amount of heat during operation, the heat spreads quickly in the plane direction of the semiconductor element placement portion 1a of the base 1 and propagates in the thickness direction of the base 1 satisfactorily. Thus, the semiconductor element 4 can always be efficiently diffused to the outside efficiently, whereby the semiconductor element 4 is always at an appropriate temperature, and the semiconductor element 4 can be stably and normally operated over a long period of time.
[0033]
The substrate 1 made of the above-described 65 to 95 wt% silicon carbide and 5 to 35 wt% copper has a linear thermal expansion coefficient of the frame insulator 2 made of a glass ceramic sintered body ( 6 ppm / ° C. to 8 ppm / ° C., which approximates 4 ppm / ° C. to 8 ppm / ° C. (room temperature to 800 ° C.). As a result, the semiconductor element 4 was activated when the frame-like insulator 2 was attached on the substrate 1. Even when heat is applied to both the base 1 and the frame-like insulator 2, a large thermal stress is generated between the base 1 and the frame-like insulator 2 due to the difference in linear thermal expansion coefficient between the two. In this way, the hermetic sealing of the space for housing the semiconductor element 4 is always perfect, and the semiconductor element 4 can be operated stably and normally.
[0034]
When the amount of silicon carbide in the substrate 1 is less than 65% by weight, in other words, when the amount of copper exceeds 35% by weight, the linear thermal expansion coefficient of the substrate 1 is greatly different from the linear thermal expansion coefficient of the frame insulator 2. As a result, the frame-like insulator 2 cannot be firmly attached to the substrate 1, and when the amount of silicon carbide exceeds 95% by weight, in other words, 5% by weight of copper. If it is less than that, the thermal conductivity of the substrate 1 is greatly deteriorated, and when the semiconductor element 4 emits a large amount of heat during operation, the heat cannot be completely dissipated to the outside through the substrate 1. If the semiconductor element 4 is heated to a high temperature, the semiconductor element 4 may be thermally destroyed, or the characteristics may vary, making it impossible to operate stably. Accordingly, the substrate 1 is specified in the range of 65 to 95% by weight of silicon carbide and in the range of 5 to 35% by weight of copper.
[0035]
The substrate 1 made of 65 to 95% by weight of silicon carbide and 5 to 35% by weight of copper has an oxide film such as SiO _{2 on} the surface of silicon carbide to a thickness of about 0.05 μm to 1 μm. If deposited, the adhesion strength between silicon carbide and copper is greatly improved, and the reliability of the substrate 1 is greatly improved. Therefore, the substrate 1 is preferably formed of silicon carbide and copper having an oxide film deposited on the surface to a thickness of 0.05 μm to 1 μm.
[0036]
As a method for depositing an oxide film on the surface of the silicon carbide, for example, silicon carbide powder is heated in the atmosphere at a temperature of about 1200 ° C.
[0037]
Further, when the base 1 is formed by dispersing and mixing silicon carbide powder in molten copper, the base 1 has a soft modulus of about 100 GPa depending on the Young's modulus of copper. Even if the semiconductor element 4 is placed on the substrate 1 and heat is applied to the base 1 and the semiconductor element 4 to generate thermal stress therebetween, the thermal stress is efficiently absorbed by slightly deforming the base 1. The semiconductor element 4 can be operated normally and stably without the semiconductor element 4 being peeled off from the base body 1 or the semiconductor element 4 being cracked or cracked.
[0038]
Thus, according to the semiconductor element storage package described above, the semiconductor element 4 is bonded and fixed onto the semiconductor element mounting portion 1a of the base 1 via an adhesive such as glass, resin, brazing material, and the like. The electrodes are connected to a predetermined wiring layer 6 via bonding wires 7, and then the lid 3 is bonded to the upper surface of the frame-like insulator 2 via a sealing material made of glass, resin, brazing material or the like. The semiconductor device 4 is hermetically accommodated in the container 5 including the base body 1, the frame-like insulator 2, and the lid body 3, thereby obtaining a semiconductor device as a product.
[0039]
In addition, this invention is not limited to the above-mentioned Example, A various change is possible if it is a range which does not deviate from the summary of this invention.
[0040]
【The invention's effect】
According to the package for housing a semiconductor element of the present invention, since the frame-like insulator is formed of a glass ceramic sintered body having a relative dielectric constant of 7 or less, the propagation speed of the electric signal transmitted through the wiring layer provided on the frame-like insulator. Therefore, it is possible to accommodate a semiconductor element that requires high-speed signal propagation.
[0041]
Further, according to the package for housing a semiconductor element of the present invention, the frame-shaped insulator is formed of a glass ceramic sintered body capable of low-temperature firing (about 800 ° C. to 900 ° C.). The wiring layer can be formed of copper, silver, or gold having a specific electric resistance of 2.5 μΩ · cm (20 ° C.) or less, and as a result, when an electric signal is propagated to the wiring layer, Large attenuation does not occur, and the electric signal can be propagated accurately and reliably.
[0042]
Further, according to the package for housing a semiconductor element of the present invention, the substrate is formed of 65 to 95% by weight of silicon carbide and 5 to 35% by weight of copper, and has a high thermal conductivity of 230 W / m · K or more. Therefore, even if the semiconductor element mounted on the base generates a large amount of heat during operation, the heat spreads quickly in the plane direction of the semiconductor element mounting portion of the base and propagates well in the thickness direction of the base. Thus, the semiconductor element can be efficiently and reliably dissipated to the outside, whereby the semiconductor element always has an appropriate temperature, and the semiconductor element can be stably and normally operated over a long period of time.
[0043]
Furthermore, according to the package for housing a semiconductor element of the present invention, the substrate is formed of 65 to 95% by weight of silicon carbide and 5 to 35% by weight of copper, and the linear thermal expansion coefficient is determined from the glass ceramic sintered body. The linear thermal expansion coefficient ( 4 ppm / ° C. to 8 ppm / ° C .: room temperature to 800 ° C.) of the frame-shaped insulator is obtained. Even when heat is applied to both the base and the frame insulator during operation, a large thermal stress is generated between the base and the frame insulator due to the difference in linear thermal expansion coefficient between the two. As a result, the hermetic sealing of the space for housing the semiconductor element is always complete, and the semiconductor element can be operated stably and normally.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an embodiment of a package for housing a semiconductor element of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Base | substrate 1a ...... Placement part 2 ... Frame-shaped insulator 3 ... Cover body 4 ... Semiconductor element 5 ... Container 6 ... .... Wiring layer 7 ... bonding wire 8 ... external lead pin

Claims (1)

A frame having a base having a mounting portion on which a semiconductor element is mounted, and a wiring layer attached on the base so as to surround the semiconductor element mounting and to which each electrode of the semiconductor element is connected A semiconductor element storage package comprising: a frame-like insulator; and a lid attached on the frame-like insulator and hermetically sealing the inside of the frame-like insulator, wherein the frame-like insulator has a dielectric constant the rate is 7 or less, a glass ceramic sintered body of the thermal expansion coefficient of 4ppm / ℃ ~8ppm / ℃, the wiring layer is electrical resistivity in the following metallic material 2.5μΩ · cm, the substrate is 65 to 95 wt% of silicon carbide and is formed by a 5 to 35 wt% of copper, the semiconductor device package for housing molten copper silicon carbide powder is characterized der Rukoto those formed are dispersed and mixed.

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