JPS6345193A - Silicon carbide base ceramic sintered body with metallized surface and manufacture - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a silicon carbide-based ceramic sintered body having a metallized surface layer and a method for manufacturing the same, and particularly to a substrate on which electronic components are mounted. The present invention relates to a silicon carbide-based ceramic sintered body suitable for application to heat dissipation members, etc., and a method for metallizing the same.

[Conventional technology]

By joining ceramics with metals or other ceramics, new functions not found in ceramics alone are created, and the range of applications of ceramics is expanded. However, when joining ceramics with other ceramics or metals, it is necessary to metalize the surface of the ceramics to facilitate joining.

For information on how to metalize non-oxide ceramics,
For example, the following method has been proposed.

JP-A-59-203780 describes a method in which the surface of a non-oxide ceramic sintered body is coated with aluminum, an alumina layer is formed, and this alumina layer is metallized. This method is described in Metallization Japanese Patent Publication No. 55-517.
No. 75 describes a method of metallizing by coating a powder of a high melting point metal such as molybdenum or tungsten on the surface of a non-oxide ceramic and firing it under pressure in a non-oxidizing atmosphere.

JP-A No. 58-99184 discloses a method for metallizing silicon carbide ceramics, in which powders of tungsten, molybdenum, titanium, manganese, etc. are applied to the surface of the ceramics, and the powder is heated to 1400°C or higher in a non-oxidizing atmosphere. A method for baking is described.

On the other hand, as a method for joining non-oxide ceramics and metals or other ceramics, Japanese Patent Application Laid-Open No. 58-135180
In this issue, an insert of an aluminum-silicon alloy is inserted between the ceramic and the metal or other ceramic,
A method is described in which direct bonding is performed by heating to about 600° C. while applying pressure in a vacuum.

[Problem that the invention seeks to solve]

The above conventional technology does not take into account the thickness of the metallized layer M (metalized layer).According to the research of the present inventors, the thickness of the metalized layer has an extremely important meaning. If it is thick, the thermal stress caused by metallization will increase, and the ceramic will break when it is joined by brazing or the like to another member having a different coefficient of thermal expansion after metallization.

Moreover, the size of the mating member to be joined is also limited. When metalizing a silicon carbide ceramic sintered body with a small coefficient of thermal expansion of approximately 4.5X10-8/"C or less, the thickness of the metallized layer should be at most 10 μm or less; if it exceeds 10 μm, It has been found that the thermal strain caused by the metallized layer alone causes the ceramic to break or become very brittle.

In the metallization method described in the prior art, all of the metal powder formed on the ceramic surface is used as a metallization layer. For this reason, it is very difficult to control the thickness of the metallized layer to 10 μm or less.

Another way to reduce the thickness of the metallized layer is to apply or print a thin layer of metal powder paste on the ceramic surface, but even in this case, all of the applied metal powder becomes the metallized layer and the thickness of the metallized layer must be 10 μm or less. It is extremely difficult to control this uniformly.

Other methods for forming a thin metallized layer include vapor deposition and ion blating, but these methods not only do not provide high bonding strength but are also not applicable to parts with complex shapes.

There are also problems with mass production.

Cutting a thick metallized layer to make it thinner would lead to cracking of the ceramic, making it nearly impossible to achieve.

An object of the present invention is to provide a silicon carbide ceramic sintered body having a metallized layer that can be formed into a thin layer with a thickness of 10 μm or less and that can be brazed to other ceramics or metals.

Another object of the present invention is to form a metallized layer on the surface of a silicon carbide-based ceramic sintered body, which can have a thickness of 10 μm or less and can be brazed with other ceramics or metals. The purpose is to provide a method for

[Means for solving problems]

In the silicon carbide ceramic sintered body of the present invention, the metallized layer is substantially composed of at least one silicide and carbide of chromium and titanium.

These silicides and carbides are formed by reaction with silicon carbide in the sintered body.

The metallization method of the present invention includes forming a metal powder layer made of at least one of chromium and titanium on the surface of a silicon carbide ceramic sintered body, and heating the metal powder to the firing temperature of the metal powder in a non-oxidizing atmosphere. The heating includes reacting a part of the metal powder with silicon carbide to produce a reaction product, and removing metal oxides present on the surface of the reaction product.

As the metal powder, chromium 11 and titanium can be used alone or in combination. When used as a composite, it may be used as a mixture or as an alloy. However, when used as a mixture or alloy, the amount of titanium may be 0.1 to 50%.
It should be kept as low as % by weight, and the rest should be chromium.

The atmosphere during firing of the metal powder is a non-oxidizing atmosphere.

Specifically, the atmosphere should be an inert atmosphere such as argon, helium, or neon, or a reduced pressure atmosphere with an oxygen partial pressure of 10<-2 >Torr or less.

The heating temperature during firing is preferably 500 to 1400"C, and when using metal powder with a particle size of 10 μm or less, a range of 800 to 1200"C is preferred, especially 90
The temperature is preferably 0 to 1000''C. The lower the firing temperature, the easier it is to control the thickness of the reaction layer.

When the metal powder is fired, a reaction layer consisting of metal silicide, which is a reaction product between the metal powder and silicon in silicon carbide, and metal carbide, which is a reaction product between the metal powder and carbon in silicon carbide, is formed. generate.

Furthermore, an unreacted metal layer containing metal oxide is formed on the reaction layer.

The metal silicides and metal carbides in the reaction layer are not uniformly mixed, but the metal silicides are abundant in the lower part near the sintered body, and the gold 7-pigment carbide increases as it goes upward.

However, it is not clearly divided into two layers such as a metal silicide layer and a metal carbide layer.

Most of the unreacted layer is silicon carbide.7. It is made of non-δ metal, and contains metal oxides near the surface.

Surprisingly, the thickness of the reaction layer is almost unaffected by increasing the coating thickness of the metal powder, and in most cases it is 10 μm.
It was confirmed that the following was obtained, and that it was usually obtained within the range of 1 to 10 μm. The greater the application thickness of the gold powder, the greater the thickness of the unreacted layer.

It is thought that the metal oxide present on the surface of the unreacted layer is generated by the reaction between the metal powder and oxygen attached during or after the formation of the metal powder layer. This unreacted layer containing metal oxides can be easily peeled off using tweezers, brushes, etc. after firing and cooling, without having to be removed by machining.
It was also found that it could be easily removed by applying adhesive tape and peeling it off. Since the unreacted metal does not particularly pose an obstacle during brazing, it is not necessarily necessary to completely remove it, and some of it may remain.

A layer made of at least one of nickel and copper is preferably provided on the exposed surface from which metal oxides have been removed so that it can be easily brazed with other ceramics or metals.A layer made of at least one of nickel and copper is preferably provided. Ha, electroplating! ! It is preferable to form by a well-known plating method such as electrolytic plating, and the thickness is preferably about 1 to 10 μm.

[Effect]

In the present invention, when a silicon carbide-based ceramic sintered body is coated with gold powder made of at least one of chromium and titanium and fired in a non-oxidizing atmosphere, the metal powder and carbonization are almost unaffected by the coating thickness. This is based on the finding that a reaction product with silicon is produced in a thickness of 10 μm or less. The components other than the reaction products are unreacted metal powder and metal oxides, and these oxides and unreacted metals can be removed very easily without causing cracks in the sintered body. . This made it possible to form a metallized layer with a thickness of 10 μm or less.

Since the thickness of the metallized layer can be reduced to 10 μm or less in this way, thermal stress is reduced, and silicon carbide ceramics can be prevented from breaking when bonded to other ceramics or metals.

The present invention will be explained in detail below.

In carrying out the present invention, a paste made by mixing various metal powders with an organic solvent is applied to the surface of a silicon carbide ceramic sintered body to a thickness of approximately 50 μm, and this is applied in an argon gas atmosphere or -7 under reduced pressure of 3 Torr
As a result of heating the ceramic at a temperature of 00 to 1400°C for 30 minutes and investigating the reaction state between the ceramic and various metal powders, the following new phenomenon was discovered.

Periodic table m a = VII a group, vm group, 1st
Among the b to IVb groups, chromium (Cr) and titanium (Ti) form a reaction layer with the ceramic.

It contained only manganese (Mn), iron (Fe), and nickel (Ni).

Furthermore, among Cr, Ti, Mn, and Fee Ni, Fe, M
The entire thickness of n and Ni applied to the ceramic surface became a reaction layer, and no unreacted Fe layer or Ni layer was formed. For this reason, coated metals (Fe, Mn
, Ni) The entire thickness of the powder became a metallized layer, and thermal stress fracture occurred in the ceramic, making it impossible to bond it to other members. In the case of Fe and Nx, it was found that the thickness of the reaction layer increased almost in proportion to the thickness of the powder applied to the ceramic surface, and that the reaction layer was entirely a metallized layer.

Moreover, only silicides were produced in the reaction layer in the case of Fe and Ni, and no carbides were produced.

From the above, it is clear that silicon carbide ceramic sintered bodies
When e or Ni layer is formed and fired, free carbon generated by decomposition of silicon carbide remains near the surface of the reaction layer,
It has been found that when Ni or copper (Cu) plating is applied after metallization, the interface strength with the plating layer is weak and a highly reliable metallized layer cannot be obtained.

On the other hand, in the case of Cr and Ti, a portion of the Cr or Ti powder applied to the ceramic surface reacts with silicon carbide to form a 1 to 10 μm thick Cr-11 reaction layer or titanium reaction layer. . Most of the remaining Cr or Ti powder exists as unreacted metallic chromium or metallic titanium, and a small portion forms oxides. It has been found that after firing and cooling, the unreacted chromium layer or the unreacted titanium layer can be easily removed with tweezers, a brush, adhesive tape, etc., without mechanical cutting.

In the case of Cr and Ti, the thickness of the reaction layer is approximately constant if the firing conditions are constant, regardless of the thickness of the Cr or Ti powder applied to the ceramic surface. The unreacted layer formed.

Adhesion to the reaction layer or ceramics was poor, and high strength could not be obtained even if Ni or Cu1i was provided on this unreacted layer and brazed.

The present invention focuses on the fact that the unreacted layer can be peeled off and removed relatively easily, and after substantially removing the unreacted layer, a Ni or Cu film is formed and bonded to other ceramics or metals. be.

In addition, as a result of identifying the reaction products of the chromium reaction layer with respect to Cr powder and silicon carbide ceramics by X-ray diffraction method, it was found that chromium silicides such as CraSi and Cr5iz and Cr
acz+ Chromium carbide such as Cr7cs, metal C
There was no r or it was rarely recognized. Furthermore, the products of the titanium reaction layer were titanium silicides such as T i S i z and titanium carbides such as TiCz, and no metallic titanium was observed.

The reaction layer thus consists essentially of silicide and carbide. Since such a reaction layer contains carbide, when joining it to other members using soft solder or hard solder, the wettability of the brazing material is poor and sound joining is difficult. Therefore, as a result of performing Ni or Cu electroplating on the reaction layer, plating could be easily performed.

By forming an Nx or Cu film on the surface of the reaction layer,
It has also become possible to join with other parts.

The method for forming the Ni or Cu film is not limited to electroplating, and may be any other method such as electroless plating, steam, or ion plating, but electroplating is particularly preferred in terms of adhesive strength and efficiency.

In the case of Ti powder, the plating properties are inferior to that of Cr powder. For this reason, it is preferable to use T1 mixed with Cr powder rather than using it alone.Titanium carbide is more thermally stable than chromium carbide, so it is preferable to use Ti powder mixed with Cr powder. As a result, a more thermally stable reaction can be obtained than in the case of using Cr powder alone. However, if the Ti amount exceeds 50% by weight, the fitting properties will deteriorate, so 50% by weight
It is desirable that the weight is less than 100%. In this case, an alloy powder of Cr and Ti may be used. The lower limit of Ti is 0.1% by weight, especially 10
Weight % or more is desirable. The Cr or Ti powder is preferably as pure as possible, but as long as the Cr or Ti component accounts for 90% by weight or more, some other metal components may be mixed in.

It has been found that the smaller the particle size of the Cr or Ti powder is, the better it is, and that the finer the particle size, the more the Cr or Ti reaction layer can be formed at a lower temperature. When firing Cv-powder in an Ar atmosphere, the appropriate firing temperature at which maximum strength is obtained is 120 μm when the particle size of Cr powder is 50 μm in the case of silicon carbide ceramics.
0~1400℃, 1100~1200"C at 3Qμm,
1000-1100℃ for 10μm, 90Q for 5μm
~1000℃, 1μm is 800~900℃+0.5
750-800℃ for μm, 600-800℃ for 0.1pm
At 700'C and 0.01 μm, the temperature was about 500°C.

The lower the firing temperature, the lower the thermal stress of the ceramic, and the higher the accuracy of printing, so the smaller the particle size, the more desirable. In particular, it is desirable that the metal powder has a diameter of 10 μm or less, which can be produced at a firing temperature of 1000"C or less. The lower limit of the metal powder is 0.
．． 01 μm is preferred.

Even if the particle size of the Cr powder and the firing temperature change, the morphology of the reaction product remains unchanged. For example, when the firing temperature is 950°C, the reaction products are silicides such as Cr5Si and Cr5iz, and C
These are carbides such as r5cz and Cr7cs. These decomposition temperatures are 1000° C. or higher for Cr3Si and Cr5iz, and 1500° C. or higher for Cr5Cz and Cr7C3. Even if the firing temperature is 1000°C or lower, the heat resistance of the reaction layer is 1400'C or higher.

It is preferable that the organic solvent used to make the Cr powder into a paste has a thermal decomposition temperature of 200'C or less because no soot or carbon will remain.

Even when painted or marked on the surface of silicon carbide ceramics, the unreacted layer cannot be easily removed.

The thickness of the unreacted layer is preferably at least 5 μm or more, and in order to achieve this, the thickness of the metal powder applied or printed on the ceramic surface is preferably 10 μm or more. However, if it is too thick, it may cause problems. 100μ because it is economical.
It is best to limit it to m8 degrees.

The atmosphere in which the silicon carbide ceramics coated or printed with paste-like Cr powder is fired is a non-oxidizing atmosphere. An inert gas atmosphere is particularly preferred. When fired in a reduced pressure atmosphere, Cr is likely to be deposited on areas other than desired areas due to evaporation of Cr, which is likely to cause a decrease in the insulation resistance of the ceramic.

In particular, when converting an electrically insulating silicon carbide sintered body containing about 1% by weight of BeO into metal, firing in an inert atmosphere is desirable.

Next, a method for bonding to metal or ceramics via the chromium reaction layer or titanium reaction layer formed by the above method will be described in detail.

By providing Cu or Ni fh after forming the chromium or titanium reaction layer as described above, it is possible to easily join the mating material with metal or ceramics, glass, etc. whose surface is metallized by soldering or hard soldering. Can be done.

When joining metals or other ceramics with different coefficients of thermal expansion, it is desirable to use another metal that has a thermal stress relieving effect between the joining surfaces.

This thermal stress relaxation material has a longitudinal elastic modulus of 12×103
A metal material or a composite material having a thickness of 112 kgf/lll or less is desirable, and a silver or a composite material having a thickness of 100 to 1000 μm as a main component is particularly desirable.

If a silver foil surface clad with silver solder is used as a thermal stress relaxation material, a highly reliable joint can be obtained.

The ceramic sintered body that is the object of the present invention may be a so-called silicon carbide ceramic sintered body that has silicon carbide as its main component, for example, silicon carbide with a small amount of a compound of zirconium and boron (ZrBz). Naturally, conductive ceramics containing the same are also covered.

〔Example〕

Embodiment 1 A package for a semiconductor device which is an embodiment of the present invention will be explained with reference to FIGS. 1 and 2. FIG.

Thickness Im, width 15m, approximately 1% by weight as sintering aid
A metallized layer was formed on the surface facing the alumina ceramic frame 2 of a cooling substrate 1 made of highly thermally conductive silicon carbide ceramic containing beryllium oxide (Bed). The forming conditions were as follows: Cr powder with a particle size of about 3 μm made into a paste with dimethyl cellulose was screen printed at a predetermined position to a thickness of about 30 μm, and this was printed in an argon (Ar) atmosphere for 90 minutes.
After baking at 50° C. for 30 minutes, it was naturally cooled. As a result, a reaction layer consisting of chromium silicide and chromium carbide and an unreacted layer consisting of unreacted metallic chromium and chromium oxide were formed. Next, the outermost unreacted Cr layer containing a portion of Cr oxide was removed using an adhesive tape, and the Cr reaction layer 3 was exposed on the surface. Then, a 5 μm thick Ni layer 4 was formed thereon by electroplating. On the other hand, on the surface of the alumina ceramic frame 2 facing the cooling substrate 1, a well-known Mo-M
An n metallized layer 5 and a Ni plating layer 6 were formed thereon. The alumina ceramic frame 2 has a 37-layer structure, and there are wiring patterns 9 between the layers. The lowermost layer (referred to as the first layer) of the frame 2 to be joined to the cooling board 1 has an opening in the center sufficient to accommodate a semiconductor device (LSI chip) 11, and The opening gradually becomes larger as it goes up to the third layer. The input/output pin 1o is connected to the wiring pattern 9.

The cooling board 11 is provided with a height-adjustable pedestal 13 in order to facilitate wiring 12 between the semiconductor device (LSI chip) 11 and the wiring pattern 9 of the alumina ceramic frame 2.

This pedestal 13 is made of a silicon carbide ceramic sintered body similar to the cooling board 1, and has a metallized layer formed in the same manner as the cooling board 1.The cooling board 1, the frame 2, and the cooling board 1 The pedestal 13 and the pedestal 13 were joined using a silver brazing filler metal 8.

A silver foil 7 with a thickness of 300 μm was used between the cooling substrate 1 and the frame 2 as a thermal stress alleviating material.

In this case, both surfaces of the silver foil were clad in advance with silver solder 8 having a thickness of 50 μm, and placed between the cooling substrate 1 and the frame 2.

JiS standard B A g -7 is used for silver soldering.
The test was carried out by heating to 00°C. Thereafter, the surface of the pedestal 13 bonded to the cooling substrate 1 is plated with gold, and the semiconductor device 1
1, the stand, and the seat 13 are made of gold-silicon (Au-8i) wax 14.
It was joined using

Regarding the semiconductor package manufactured as described above,
As a result of applying a thermal cycle from -50℃ to 150℃ and performing a helium (He) leak test before and after the thermal cycle, the number of thermal cycles was 10,000 and the amount of He leakage was IX 10-"atm-cc. High reliability was confirmed at less than / s.

Example 2 In the third country, about 1% by weight of BeO was added and hot-pressed to give a thermal conductivity of 270 W/mK, an electrical insulation resistance of 1012 Ω, and a thermal expansion coefficient of 3.7 x 10-6.
It consists of a silicon carbide-based ceramic sintered body 20 with a thickness of 2 mm and a size of 76 m square having the characteristics of
f! &, expansion coefficient is 4.6 x 10-”7℃, thickness 1
Carbide frame 1 with a width of 0m2 and an outer diameter of 75mm.
Fig. 5 shows a cross section of the parts 5 and 5 joined together according to the present invention.

Cr powder with a particle size of 1 μm made into a paste of dimethylene glycol monoethyl ether acetate and ethyl cellulose is applied to a thickness of about 4 μm on the joint portion of the silicon carbide ceramic sintered body 2o. This was baked at a temperature of 900° C. for about 30 minutes in an Ar atmosphere and then naturally cooled. As a result, about 2
μm of Cr silicide (CrSiz, Cr5Si) and C
A Cr reaction layer 3 made of r carbide (Crzc2.Cr7ca) was formed, and the remaining Cr powder was formed as an unreacted Cr layer on the Cr reaction layer. Next, the unreacted Cr layer was removed with tweezers, and Ni was added to the surface of the Cr reaction layer 3.
A plating layer 4 having a thickness of 5 μm was formed by electroplating.

On the other hand, N1-plated M4 was also formed on the joint surface of the carbide frame 15 to a thickness of 6 μm by electroplating.

The silicon carbide ceramic sintered body 2Q whose joint surface has been metallized by the above method and the carbide frame 15 are soldered with silver solder (J
Brazing was performed at 800°C in nitrogen gas containing 10% hydrogen using IS BAg-8) 8. Note that the thickness of the silver solder in this case is about 30 μm. The mullite ceramic substrate 16 with the semiconductor device @ 11 bonded to the end face of the carbide frame 15 bonded in this way is soldered 17.
were bonded together to form a package for semiconductor devices.

Thermal cycle test (15
0℃←→-50'C) 1000 times, and He
As a result of the leak test, the amount of Ha leak was l x 1
It was confirmed that it could be used as a semiconductor package at 0-10-1 Oatc/s. Note that in this example, since the coefficients of thermal expansion of both materials are almost the same, no thermal stress relieving material was used.

As a result of measuring the tensile strength of the joined body joined by the above method, a strength of about 20 kg f/me2 was obtained.

Furthermore, when the tensile strength of the bonded body bonded by the above method was determined after heating it to 700° C., no decrease in bonding strength was observed, indicating that the bonded body had high heat resistance.

Example 3 A hot-pressed silicon carbide ceramic sintered body with a thickness of 2 mm, vIi and width of 20+n++ using approximately 5% by weight of aluminum nitride (AQN) as a sintering aid was coated on one side as in Example 2. A paste-like Cr powder with a particle size of about 5 μm was printed with a thickness of about 50 ALm in a straight fJ 5 m, and this was heated between 700 and 1300° C. for 30 minutes in an argon atmosphere.
After baking for a minute, it was naturally cooled. As a result, Cr silicide and C with a thickness of about 1 to 15 μm were deposited on the surface of the ceramic sintered body.
a reaction layer made of r carbide, made of metal Cr on it,
An unreacted layer about 30 am thick containing some chromium oxide was formed. The unreacted Cr layer formed as the outermost layer was removed using a metal brush to expose the Cr reaction layer on the ceramic surface, and Ni was electroplated thereon to a thickness of about 5 μm.

A copper wire with a diameter of 2 m was bonded to the metallized surface formed by the above method using silver solder at a temperature of 800'C. After this,
A tensile test was conducted by pulling in the vertical direction.

Fig. 4 shows the relationship between firing temperature and bonding strength, and Fig. 5 shows the relationship between Cr layer thickness and bonding strength. It is also found that high-strength bonding can be achieved when the thickness of the reactive Cr layer is 1 to 10 μm.

Example 4 Electrical resistance containing about 40% by weight of ZrB2 is 1 x 104Ω
Cr powder with a grain size of about 10 μm was made into a paste and applied to a part of one surface of a conductive silicon carbide ceramic sintered body measuring 1 m in thickness and 3 m x 50 m in thickness to a thickness of about 500 μm. This was baked at 1000° C. for 30 minutes under a reduced pressure of 5×10 −4 Torr, and then naturally cooled. Thereafter, the unreacted Cr layer including a part of the Cr oxide layer on the metallized surface was removed, and Ni plating was performed to a thickness of about 3 μm. A Ni wire with a diameter ILffo was silver soldered to the Ni-plated surface and used as a heater for ignition.

This ignition heater was subjected to a thermal cycle test from 600℃ to 20℃.
Even when the bonding was repeated 20,000 times in the temperature range of .degree. C., no decrease in bonding strength was observed.

Example 5 0.1 to 6 Ti powder of the same particle size was added to Cr powder of 3 μm particle size.
The mixed powder containing 0% by weight was made into a paste, and this was printed on a silicon carbide ceramic sintered body that had been sintered without pressure. Then, it was fired at 950° C. for 30 minutes in a vacuum with a degree of vacuum of 1×10″’’ Torr. By firing, a reaction layer consisting of Cr carbide, Cr silicide, T1 carbide and Ti silicide and a layer consisting of oxides of metal Cr, gold, @"ri, cr and Ti are formed on the surface of the silicon carbide ceramic sintered body. A reaction layer was formed.The unreacted layer was removed by brushing.

Ni was plated on the reaction layer, and a Ni wire having a diameter of 3ffn+ was brazed with gold-palladium solder. Thereafter, the joint was pulled vertically at high temperature to test the heat resistance of the joint. Figure 6 shows the incorporation of Ti into the resulting Cr powder.
The relationship between content and heat-resistant temperature is shown. Ti content is about 50
It can be seen that the heat resistance palpitation gradually increases up to % by weight.

Example 6 Paste-like Cr powder with a particle size of 0.01 to 30 μm was
A portion of the silicon carbide-based ceramic sintered body was printed with a thickness of μm, and this was fired in an Ar atmosphere with a purity of 99.9% or a reduced pressure atmosphere with a degree of vacuum of I x 10-10 Torr. The relationship between chromium powder particle size and optimum firing temperature is shown in the seventh section.
As shown in the figure.

In either case, the optimal firing temperature decreases as the particle size of the Cr powder decreases, and the optimal firing temperature for 0.01 μm Cr powder is 400°C in an Ar atmosphere.
It was found to be 200'C in a vacuum of 1OTorr. However, even when firing at such a low temperature, the reaction products formed were similar to those at high temperatures, so no decrease in the heat resistance of the metallized layer was observed.

[Effects of the Invention] According to the present invention, a strongly bonded thin reaction layer having a thickness of 10 μm or less can be formed on the surface of a silicon carbide ceramic sintered body. It is extremely easy to plate Cu or Ni on the surface of this reaction layer, and it is possible to firmly bond metal members or other ceramic members through these plated layers, resulting in a bonded body with high heat resistance and high strength. be able to.

[Brief explanation of the drawing]

FIGS. 1 to 3 are cross-sectional views showing one embodiment of the present invention, and FIG.
Figures 5 to 5 are characteristic diagrams showing the relationship between the thickness of the 6-line silicon carbide-based ceramic sintered body with a metallized layer and the bonding strength, and Figure 6 is a characteristic diagram showing the relationship between the thickness of the 6-line silicon carbide-based ceramic sintered body and the bonding strength. T
FIG. 7 is a characteristic diagram showing the y coefficient between the amount of Cr powder and the heat resistance of 1 degree of the resulting joint, and FIG. 7 is a characteristic Σ showing the relationship between the particle size of the Cr powder and the firing temperature. 1... Silicon carbide ceramic cooling substrate, 3--Chromium reaction layer, 4... Nickel layer, 8... Silver solder, 11
...Semiconductor device, 13...Silicon carbide ceramic pedestal.

Claims (1)

[Scope of Claims] 1. A silicon carbide-based ceramic sintered body having a metallized layer on its surface, wherein the metallized layer consists essentially of at least one silicide and carbide of chromium and titanium; A silicon carbide-based ceramic sintered body having a metallized surface, characterized in that the silicide and the carbide are produced by a reaction with the silicon carbide. 2. Claim 1, wherein the metallized layer comprises:
A silicon carbide ceramic sintered body having a metallized surface, characterized in that it has a multilayer structure including a lower layer containing the silicide as a main component and an upper layer containing the carbide as a main component. 3. Claim 1, wherein the metallized layer comprises:
A silicon carbide ceramic sintered body having a metallized surface containing at least one of unreacted metallic chromium and metallic titanium. 4. Claim 1, wherein the metallized layer comprises:
A silicon carbide ceramic sintered body having a metallized surface consisting essentially of chromium silicide and chromium carbide. 5. Claim 1, wherein the metallized layer comprises:
A silicon carbide ceramic sintered body having a metallized surface comprising chromium silicide, chromium carbide, and metallic chromium. 6. Claim 1, wherein the metallized layer comprises:
A silicon carbide ceramic sintered body having a metallized surface consisting essentially of titanium silicide and titanium carbide. 7. Claim 1, wherein the metallized layer comprises:
A silicon carbide-based ceramic sintered body having an all-metallic surface characterized by being composed of titanium silicide, titanium carbide, and metallic titanium. 8. In a silicon carbide-based sintered body having a metallized layer on the surface thereof, the surface of the sintered body is substantially composed of silicide produced by a reaction between at least one of chromium and titanium and the silicon carbide. A silicon carbide-based ceramic sintered body having a metallized surface, comprising a layer made of carbide and a layer made of at least one of nickel and copper thereon. 9. A silicon carbide-based ceramic sintered body having a metallized surface, characterized in that it has a plating layer made of at least one of nickel and copper as set forth in claim 8. 10. A method for forming a metallized layer on the surface of a silicon carbide-based ceramic sintered body, including forming a metal powder layer made of at least one of chromium and titanium on the surface of the sintered body, and in a non-oxidizing atmosphere. heating to the firing temperature of the metal powder and causing a part of the metal powder to react with the silicon carbide; and removing at least oxides on the surface of the layer generated by the heating. 1. A method for producing a silicon carbide-based ceramic sintered body having a metallized surface, the method comprising the steps of: 11. Claim 10, wherein the heating produces a reaction layer consisting of a lower layer mainly composed of a silicide of the metal and an upper layer mainly composed of a carbide of the metal;
A method for producing a silicon carbide ceramic sintered body having a metallized surface, characterized in that an unreacted layer consisting of an unreacted metal and an oxide of the metal is formed on the reaction layer. 12. A method for producing a silicon carbide ceramic sintered body having a metallized surface as set forth in claim 11, characterized in that the unreacted layer is substantially removed to expose the reacted layer. 13. The silicon carbide having a metallized surface according to claim 11, wherein the metal oxide in the unreacted layer is removed and a part of the unreacted metal remains on the exposed surface. A method for producing ceramic sintered bodies. 14. According to claim 10, the metallized surface is characterized in that the metal powder is mixed with an organic solvent having a thermal decomposition temperature of 200° C. or less to form a paste and applied to the sintered body. A method for producing silicon carbide ceramic sintered bodies. 15. A method for producing a silicon carbide ceramic sintered body having a metallized surface, characterized in that the metal powder has a particle size of 10 μm or less and 0.01 μm or more. . 16. A method for producing a silicon carbide-based ceramic sintered body having a metallized surface as set forth in claim 15, wherein the heating temperature is in a range of 800°C or higher and 1200°C or lower. 17. A method for manufacturing a silicon carbide ceramic sintered body having a metallized surface as set forth in claim 10, characterized in that the metal powder is formed to have a thickness of 10 μm or more and 100 μm or less. 18. In claim 10, the silicon carbide-based metal powder having a metallized surface is characterized in that the metal powder consists of 0.1 to 50% by weight of titanium and the remainder substantially chromium. A method for producing ceramic sintered bodies.