JP2898877B2 - Aluminum nitride sintered body having conductive metallized layer and method of manufacturing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [0001] BACKGROUND OF THE INVENTION The present invention has a conductive metallized layer.
Aluminum nitride sintered body and its manufacturing method
And, more specifically, with the aluminum nitride sintered body base material.
Aluminum nitride with conductive metallized layer with high bonding strength
Aluminum sintered body and this metallized layer
The production method of sintering and simultaneously forming the sintering precursor
You. [0002] 2. Description of the Related Art Aluminum nitride sintered body has good thermal conductivity.
Good heat dissipation and excellent electrical insulation
It is drawing attention as a substrate material for the body. [0003] This aluminum nitride sintered body is generally as follows.
It is manufactured in this way. That is, aluminum nitride powder
To Yttria (Y_TwoO_Three), Samaria (Sm_TwoO_Three),
A predetermined amount of a sintering aid such as calcia (CaO) is blended,
Add acrylic resin binder etc. as needed
And thoroughly mix the whole.
Molded aluminum nitride sintering precursor (formed
Shape), and then set this in a nitrogen atmosphere, for example.
Sinter at temperature. By the way, aluminum nitride is used as a substrate for a semiconductor.
When using a minium sintered body, this aluminum nitride
It is necessary to form a conductive thin layer on the surface of the
Become. Conventionally, this thin layer is the surface of the aluminum nitride sintered body.
DBC method (Direct Bond Cupper method)
(Cu) and gold (A) formed by applying
u), a metallized layer of silver-palladium (Ag-Pd)
there were. However, in this conventional substrate,
There are the following problems. First, the formed metallized layer
Bonding strength between aluminum and aluminum nitride sintered body surface is often low
And the separation phenomenon occurs between them, and the reliability of the substrate is low.
That's what it means. The second problem is that the formed metallized layer has a problem.
Brazing certain semiconductor elements or wires or high temperature
This is a problem that occurs when soldering or the like. sand
That is, for example, in the case of brazing,
At about 800 ° C.
The temperature during baking is usually about 600-1000 ° C
Because of the low temperature, the metallization layer
Significant decrease in bonding strength with aluminum nitride sintered body surface
That makes brazing virtually impossible
It is. Similar problems also occur with high-temperature soldering
I do. [0008] The third problem is that aluminum nitride sintered body and
This is a problem based on the difference in the coefficient of thermal expansion from the metallized layer.
That is, even in brazing and high-temperature soldering.
To mount semiconductor devices such as silicon wafers
The substrate used is subjected to severe heat-cooling thermal cycles during its use.
Experience As a result, the aluminum nitride sintered body-
Tally layer-brazing layer (or solder layer)-semiconductor element
Each joint surface of the element is based on the difference in the coefficient of thermal expansion of each layer.
Thermal stress is generated, and there is no action to separate them.
You. In the case of the above metallized layer, aluminum nitride
Sintered body (Thermal expansion coefficient is about 4.6 × 10^-6/ ° C) heat
Its value is about 2 to 4 times larger than the coefficient of expansion and brazing
From the same value as the layer (or solder layer)
Is significantly different from aluminum nitride,
Sometimes metallization or brazing layers (or soldering
Cracks occur at the interface between layer and aluminum nitride
It's easy to do. As a result, as the thermal cycle is weighted
These tiny cracks gradually develop and eventually mount
This may cause peeling of the semiconductor element. [0010] Such a problem is caused by mounting the semiconductor element.
The reliability of the equipment mounting the
It is convenient. A fourth problem is that the metallized layer and the nitride
Low bonding strength at high temperature with luminium sintered body
The reliability at high temperature use is low as in the second case.
That is. A fifth problem is that a completed substrate is not
It is uneconomical in terms of using heat energy if the production process is reversed
That is. That is, to obtain a completed substrate
To sinter the aluminum nitride precursor,
The sintered body was fired again to form a metallized layer.
That is, [0013] SUMMARY OF THE INVENTION The present invention is as described above.
Metallized layer and aluminum nitride sintering
High bonding strength with body surface, no peeling phenomenon,
No inconvenience occurs when brazing or soldering, and
A highly reliable conductive metallization layer that is resistant to thermal cycling
To provide an aluminum nitride sintered body having
Sintering of aluminum nitride precursor
The surface has a coefficient of thermal expansion similar to that of aluminum nitride sintered body.
Conductive metal with high heat resistance and high bonding strength
An object of the present invention is to provide a manufacturing method for forming a noise layer. [0014] Means for Solving the Problems The present inventors have achieved the above object.
As a result of intensive research to achieve
Forming a metallized layer with components selected from
That the conductive metallization of the present invention can be achieved.
Thus, an aluminum nitride sintered body having a closed layer was completed. That is, the conductive metallized layer of the present invention has
Aluminum nitride sintered body is molybdenum, tungsten
Consists of ten and tantalumGroupAlone or selected from
One or more selected from those compounds,A
LuminiumAlone orThatOne kind selected from compounds
Or two or more, andTitaniumAlone orThatCompound
One or more species selected fromTitaniumhydrogen
When selecting only the compound and / or oxide, the weight ratio
At least one-tenth of the total amount of the group)
Aluminum metal nitride layer
Having at least a portion of the surface of the consolidated base material, and
The metallized layer and the aluminum nitride sintered body base material
It is characterized by being sintered at the same time. HereIn moMolybdenum (Mo), tungsten
(W) and tantalum (Ta) both have high melting points
Metal with excellent heat resistance and aluminum nitride
It has a coefficient of thermal expansion approximately similar to that of the consolidated base metal
The heat resistance and heat cycle characteristics of the metallized layer
It is a component that contributes to improving the properties. [0017]hereMo and W are preferable, and a simple substance is particularly preferable.
Good. [0018]ALuminium (Al) Is, Aluminum nitride
Good wettability with the base metal and metallization layer / intermediate layer
A component that protects the reaction and forms a strong metallized layer.
To. [0019]aluminumAmong them, nitride, oxidation
Are particularly preferred. [0020]TitaniumIs the metallized layer forming process,
In other words, in the heating step, wetting with the aluminum nitride base material
Conductive metallization layer and aluminum nitride
Is a component contributing to the improvement of adhesion to the base metal.
TitaniumWhen only hydrides and / or nitrides are used
If the weight ratioThe groupMore than one-tenth of the total amount of
Is used. [0021]Among titaniumTi nitrides and oxides
TiN and TiO2 are particularly preferred. As the conductive metallized layer,,Ribde
Selected from the group consisting of tungsten, tungsten and tantalum
One or two or more of the conductive metallized layers
When the content is 0 to 95% by weight, the above heat resistance and heat resistance
It is suitable in terms of cycle characteristics. The conductive metallized layer of the present invention has
Aluminum nitride sintered bodies are particularly favorable as substrates for semiconductors.
Suitable. Further, the present inventors have considered the fifth problem.
As a result of intensive studies, aluminum nitride before sintering was
The paste described below is applied to
Aluminum nitride sintering of excellent metallized layer when sintering
Found that it can form on the surface of the body,
Aluminum nitride sintering with bright conductive metallization layer
The body manufacturing method was completed. That is, the conductive metallized layer of the present invention is provided.
Aluminum nitride sintered body
Molybdenum, tungsten and
Made of tantalumGroupSimple substance selected from them or their conversion
One or more selected from the compound,aluminum
ofAlone orThatOne or more selected from compounds
Above andTitaniumAlone orThatOne selected from compounds
Or two or more (butTitaniumHydride and / or
When only oxide is selected, the weight ratio of the total amount of the group is
More than one tenth).
It is characterized by sintering and then sintering the whole. [0026]Molybdenum, tungsten and tantalum
Group consisting ofAbout heat resistance and heat cycle characteristics
It is preferable to use a simple substance which shows which property best. Ma
WasAluminum and titanium areWettability with aluminum nitride
Nitrides and / or oxides with the best properties such as
It is preferable to use On this occasion,TitaniumHydride and
When only oxides and / or oxides are used,
To exceed one tenth of the total amount of the group
Is the same as A paste for forming a conductive metallized layer and
Then,From ribden, tungsten and tantalum
One or more selected from the group consisting ofThe group and
And aluminum and titanium50-95% by weight of the total
In this case, the heat resistance and heat cycle characteristics described above are favorable.
Suitable. First, the aluminum nitride applied to the present invention
The sintering precursor is, for example, aluminum nitride powder having a predetermined particle size.
And Y_TwoO_Three, YF_Three, Sm_TwoO_Three, CaCO_ThreeAs
Sintering aid powder and wax-based or plastic-based
Such a binder component is mixed at a predetermined ratio, and
Pressing or shaping body at room temperature
It is a molded article formed more into a sheet. Aluminum nitride
Particle size, mixing ratio, or molding pressure of
Relationship between the properties of the target aluminum nitride sintered body
Is selected as appropriate. In the production method of the present invention,
Aluminum sintering precursor has a thermal conductivity of 5 after sintering.
It is preferable that it is more than 0W / m · K.
No. The aluminum nitride sintering precursor is described below.
A paste having the following composition is applied. As the application method,
For example, screen printing, brush coating, spin roller coating
For example, a known method may be applied. The paste according to the production method of the present invention is
After forming, convert to metallized layerThe above group, aluminum compound
Object, titanium compoundAnd a medium for dispersing them
Is done. WhereThe above groupMolybdenum, tan
Simplex selected from the group consisting of gustene and tantalum
Or one or more selected from those compounds
is there. Specifically, the components are as follows. Sand
Molybdenum, tungsten or tantalum simple gold
Metal; these various oxides; these various nitrides; these
Various carbides; these various borides;
Iodides; these various oxynitrides; these various carbonitridings
Products; these various halides; these various hydrogenations
Substances; these various hydroxides; these various nitrites, nitrates
Acid salt, sulfite, sulfate, borate, carbonate, silicic acid
Salt, phosphate, phosphite, hydrochloride, chlorate, oxalate
Salts such as acid salts and ammonium salts; Atron NT
a / 700 (trade name: manufactured by Nippon Soda Co., Ltd.)
Various organometallic compounds such as oxides and sol-gels;
A mixture of two or more of the above components appropriately mixed
Can be given. Each of these components alone
May be used, or two or more selected appropriately
They may be used together. When the conductivity of the metallized layer to be formed is increased,
In this respect, Mo, W, and Ta are particularly simple metals.
Is preferred. In addition, the melting point is high,
W and Mo are particularly preferred for their excellent stability in
No. Next,aluminumAs the aluminumM
singleBody orThatOne or more selected from compounds
It is. [0036] Specifically, the components are as follows. Sand
C, aluminumSimpleBody metal;thisVarious oxides;thisVarious
Nitrides;thisVarious carbides;thisVarious borides;thisVarious
Silicide;thisVarious oxynitrides;thisVarious carbonitrides;this
Various halides;thisVarious hydrides;thisVarious hydroxylation
Stuff;thisVarious nitrites, nitrates, sulfites, sulfates,
Borate, carbonate, silicate, phosphate, phosphite, salt
Such as acid salts, chlorates, oxalates and ammonium salts
Various salts; various salts such as alkoxides and sol-gels
Metal compounds; and two or more of the above-mentioned components as appropriate
Can be given as a mixture. These ingredients
May be used alone or selected appropriately.
Two or more kinds may be used in combination. Also,Titaniumas,TitaniumAlone or
ThatOne or more selected from compounds. Specifically, the components are as follows. Sand
Chi, ChitaSimpleBody metal;thisVarious oxides;thisVarious nitriding
Stuff;thisVarious carbides;thisVarious borides;thisVarious Kei
monster;thisVarious oxynitrides;thisVarious carbonitrides;thisVarious
Halide;thisVarious hydrides;thisVarious hydroxides;
thisVarious nitrites, nitrates, sulfites, sulfates, boric acid
Salt, carbonate, silicate, phosphate, phosphite, hydrochloric acid
Each such as salt, chlorate, oxalate, ammonium salt
Seed salt; Atron NTi (trade name: Nippon Soda Co., Ltd.)
Alkoxides, etc., various organic golds like sol-gel
Genus compound; and two or more of the above-mentioned components appropriately mixed
Combined mixtures can be given. These components are
Each of them may be used alone, or two appropriately selected
You may use it combining the above. TheseSaid group, aluminum and titanium
Paste according to the present invention by uniformly dispersing the components of
Is prepared. As a medium to be used, for example, ethyl cellulose
And nitrocellulose and terpine as their solvent
All, tetralin, butyl carbitol, etc.
be able to. At this timeThe groupIngredients andAluminum and
And titaniumThe weight ratio of the components
Depends on the type ofThe group: aluminum
Mu + titanium= 1: 100 to 100: 1. Special
If 95: 5 to 50:50, heat resistance and heat resistance
It is suitable in terms of the hull characteristics. [0042]The groupThe components ofAluminum components and
Components of titaniumIf too much more thanPrevious
Chronicles / Aluminum + TitaniumFormed if> 95/5
The strength of the metallized layer
No. And if too little, ieThe group / Aluminium
Mu + titaniumIn the case of <50/50, the conductivity is low.
Again, it is not desirable. Also,Aluminum: Titanium= 1: 10
If it is 2: 1, the wettability with the aluminum nitride base material is
Is particularly suitable. [0044]Said group, aluminum and titaniumIngredients
The amount of dispersion of the paste in the medium depends on the consistency of the paste obtained.
It is determined as appropriate by the staff.The groupIs too large,
Paste becomes highly viscous and before aluminum nitride sintering
Uniform application to the surface of the precursor becomes difficult. And vice versa
The groupIs too small, the viscosity of the paste will be low.
Too much, the applied paste is aluminum nitride sintering precursor
It flows away from the surface of the body. Usually the paste viscosity is
1.0 × 10^Five ~ 2.5 × 10^Five To be poisePrevious
Writing groupMay be dispersed. In the production method of the present invention, the paste
After coating on the surface of aluminum nitride sintered precursor, the whole
At the same time. Prior to this simultaneous sintering, aluminum nitride
Components of Sintered Precursor and Medium of Paste
For example, to remove 50 to 700 ° C.
The degreasing treatment may be performed at a temperature. The sintering is performed in a non-oxidizing atmosphere, but in a nitrogen atmosphere.
It is preferably performed in an atmosphere. The sintering temperature and sintering time
After sintering, the aluminum nitride sintered body has desired properties,
Set as a condition to have a conductivity of 50 W / mk
Is done. Specifically, a sintering temperature of 1600 to 2000 ° C,
It is preferably 1700-1800 ° C., and the sintering time is
0.2-5 hours, preferably 0.5-1.5 hours
You. Thus, the aluminum nitride sintered body
Metallized layer with applied paste changed on the surface of
Are formed as a conductive thin layer. [0048] The present invention provides an aluminum nitride having a conductive metallized layer according to the present invention.
According to the minium sintered body, the base material aluminum nitride
High bonding strength with sintered body, excellent heat resistance, thermal expansion
Metallized layer whose rate is similar to aluminum nitride sintered body
can get. Further, it has the conductive metallized layer of the present invention.
According to the manufacturing method of the aluminum nitride sintered body,
This is advantageous in terms of manufacturing, and simplification of the manufacturing process can be realized. [0050] Embodiments of the present invention will be described below. -Example 1 (1) Preparation of pasteThe group Molybdenum alone with a particle size of 0.5 to 1.0 μm
PreparealuminumThe particle size is 1.0 to 2.
0 μm aluminum nitride powder,TitaniumIngredients and
To prepare a titanium nitride powder with a particle size of 1.0 to 2.0 μm
Was. The weight ratio of molybdenum: aluminum nitride
Um: titanium nitride = 2: 1: 1 (50:25:25)
Mixed. With respect to 100 parts by weight of the obtained mixed powder,
7 parts by weight of cellulose, and a viscosity of 2.0 × 10^Five
Poise paste. (2) Formation of metallized layer Nitrogen containing 3% by weight of yttrium oxide as a sintering aid
(1) on one side of a green sheet of aluminum chloride
The produced paste was applied by a roller with a thickness of 15 μm. Then, it is baked in a nitrogen atmosphere at 700 ° C. for 3 hours.
After the degreasing treatment, the whole was placed in a nitrogen stream,
Sintered at 00 ° C for 2 hours. The obtained aluminum nitride sintered body sheet
A metallized layer was formed on the surface. This metalla
The constituent phases of the alloy layer are Mo, AlN and TiN.
Confirmed by line diffraction. (3) Metallized layer and sintered aluminum nitride sheet
Joint strength Electroless plating on the metallized layer obtained in (2)
Therefore, a nickel plating layer having a thickness of about 3 to 5 μm is formed.
Was. Next, the plating layer is formed in a homing gas at 800 ° C.
After annealing, wire diameter 0.5mm, tensile strength
55kg / mm^TwoOf Kovar wire using silver brazing
I did. Brazing temperature is 800 ° C, atmosphere is hydrogen 50V
ol% and a mixed gas atmosphere of 50 vol% of nitrogen. Then, the aluminum nitride sintered body sheet is
Fix and pull Kovar wire at room temperature (20 ° C).
The peeling state of the oil layer was observed. Tensile strength 2 kg / mm^Two When Metalla
The brazing portion of the Kozal wire was cut off from the layer.
In other words, aluminum nitride sintered sheet and metallized
The bonding strength with the layer is 2kg / mm^Two Turned out to be more than
did. -Example 26 Said group, aluminum and titanium Table of each component
1 was selected as shown in FIG.
Preparation of paste, aluminum nitride green sheet surface
And sintering under the conditions shown in Table 1.
Was. The meta in the obtained various sintered body sheets
Bond strength between rise layer and aluminum nitride sintered sheet
Was measured in the same manner as in Example 1. Summarize the results
The results are shown in Table 1. [0058] [Table 1]-Comparative example 1 Three nitrides having a thermal conductivity of 70 to 130 W / mk
Apply the thick film method to the surface of the
The gold, silver and silver-palladium layers were baked. Each of the obtained metallized layers has a nickel
After soldering the plated copper pins,
Metallized layer and aluminum nitride sintered plate
The bonding strength with the surface was measured. In each case, about 1
kg / mm^TwoMet. -Comparative example 2 Aluminum nitride having a thermal conductivity of 70 to 130 W / mk
The paste used in Example 3 was applied to the surface of a sintered metal plate.
Baked at 1700 ° C. 70 in the resulting metallized layer
Braze the Kovar pin at 0-800 ° C,
When the joint strength was measured by pulling, 2kg
/ Mm^TwoMet. [0060] As is apparent from the above description, the present invention
Aluminum nitride sintered body having conductive metallized layer
Is the bonding strength of the aluminum nitride sintered body
, A conductive metallized layer having a high level was formed. Also,
Molybdenum, tungsten and tantalum
High heat resistance due to containing high melting point metal such as
And the coefficient of thermal expansion is similar to that of aluminum nitride sintered body.
Value, it also has a function as a thermal shock layer.
You. Further, it has the conductive metallized layer of the present invention.
Aluminum nitride sintered body
Pace applied simultaneously with sintering of sintering precursor
Is converted to a metallized layer, which is
It has the effect of becoming. Further, it has the conductive metallized layer of the present invention.
Aluminum nitride sintered body
From igniter, high frequency transformer, condenser
Substrate members; insulating tube for laser tube, insulating envelope for power tube
Vessel, window of high-frequency electromagnetic wave traveling wave tube, irradiation of high energy beam
Windows, magnetron-like members, tube heaters
ー, surface heater, sheathed heater, soldering iron, iron
Press plate, moxibustion appliance, heater for coffee maker
ー, trouser press, hot plate, toilet seat, cooking
Pan, thermal transfer printer head, plug, thermocouple protection
Protection tube, crucible scissors tip, crucible for melting metal, single connection
It can be applied to materials such as crucibles for crystal pulling.
Weirdly useful.

────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shun-ichiro Tanaka 8 Shinsugita-cho, Isogo-ku, Yokohama-shi, Kanagawa Prefecture Toshiba Corporation Yokohama Metal Works (56) References JP-A-61-291480 (JP, A) (58) Field surveyed (Int.Cl. ⁶ , DB name) C04B 41/80-41/91

Claims (1)

(57) [Claims] Made of molybdenum, tungsten and tantalum
One or more selected from a single piece or a compound thereof selected group or al and, one or more selected from a single piece or a <br/> compound of aluminum, and titanium
If one or more selected from emissions of simple substance or a compound thereof (except choosing only hydrides and / or oxides of titanium, of 10 minutes of the total amount of said group in a weight ratio of 1
The conductive metallized layer and the aluminum nitride sintered body base material are simultaneously formed on at least a part of the surface of the aluminum nitride sintered body base material. An aluminum nitride sintered body having a conductive metallized layer characterized by being sintered. 2. 2. The aluminum nitride sintered body having a conductive metallized layer according to claim 1, wherein a single element selected from the group is used. 3. 2. The aluminum nitride sintered body having a conductive metallized layer according to claim 1, wherein the element selected from the simple substance of aluminum or a compound thereof is a nitride and / or an oxide. 4. 2. The aluminum nitride sintered body having a conductive metallized layer according to claim 1, wherein the element selected from the titanium simple substance or the compound thereof is a nitride and / or an oxide. 5. Alone or claim 1 or 4 conductive metallized layer aluminum nitride sintered body having a described are of the chosen from the compounds is TiN or TiO2 of the titanium. 6. The aluminum nitride sintered body having a conductive metallized layer according to claim 1 or 2, wherein the group accounts for 50 to 95% by weight of the conductive metallized layer. 7. The conductive metallized layer of aluminum nitride sintered body having found one claims 1 is a semiconductor substrate 6
An aluminum nitride sintered body having the conductive metallized layer according to claim 1 . 8. A sintered aluminum precursor nitride, molybdenum, and one or more selected from a single selected group or al of tungsten and tantalum or a compound thereof, one selected from simple substance or a compound of aluminum Or two or more, and one or two or more selected from a simple substance of titanium or a compound thereof (however, when only a hydride and / or oxide of titanium is selected, 10 minutes of the total amount of the group by weight ratio is selected) A method for producing a sintered body of aluminum nitride having a conductive metallized layer, which comprises applying a paste containing: 9. The method for producing an aluminum nitride sintered body having a conductive metallized layer according to claim 8 , wherein the element selected from the group is a simple substance. 10. 9. The method for producing an aluminum nitride sintered body having a conductive metallized layer according to claim 8, wherein the simple substance of aluminum or a compound thereof is a nitride or an oxide. 11. 9. The method for producing an aluminum nitride sintered body having a conductive metallized layer according to claim 8, wherein the simple substance of titanium or a compound thereof is a nitride or an oxide. 12. The method for producing an aluminum nitride sintered body having a conductive metallized layer according to claim 8 or 11, wherein the titanium simple substance or its compound is TiN or TiO2. 13. The method for producing an aluminum nitride sintered body having a conductive metallized layer according to claim 8 or 9, wherein the group accounts for 50 to 95% by weight of the entire paste. 14． The method for producing an aluminum nitride sintered body having a conductive metallized layer according to any one of claims 8 to 13 , wherein the aluminum nitride sintered body having the conductive metallized layer is a substrate for a semiconductor.