JPH0679991B2 - Metallization composition of nitride ceramic body and metallization method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a metallized composition, and more particularly to a metallized composition containing an oxynitride glass component to form a metallized layer on the surface of a nitride ceramic body. The present invention relates to a metallized composition useful for Furthermore, the present invention relates to a method for metallizing a nitride ceramic body using this composition.

[Prior art and its problems]

Recently, the joining of ceramic bodies and metals plays a very important role in the composite engineering of both materials. With the development of new materials for ceramic bodies, attention has been paid to silicon nitride ceramics, which have excellent properties that conventional oxide ceramic bodies do not have, such as high-temperature and high-strength characteristics. Excellent strength is required.

A high temperature metal method (for example, the Telefunken method) is known as a metallizing method used for the above joining.

However, even if the nitride ceramic body is metallized by the conventionally known high temperature metal method, the adhesive strength is poor and there is a problem that it is easily peeled off.

[Means for solving problems]

The inventors of the present invention have conducted intensive studies in view of the above circumstances, and a composition containing an oxynitride glass having a specific composition and a high melting point metal powder, which will be described in detail below, firmly adheres to the nitride ceramic body and peels off. It has been found that a metallized layer with excellent strength can be formed on this ceramic body.

That is, according to the present invention, an element of Group IIa or Group IIIa of the periodic table.
Provided is a metallized composition for a nitride ceramic body, which is essentially composed of at least one selected from Group a elements, oxynitride glass of aluminum and silicon, and a refractory metal powder.

Furthermore, according to the present invention, the periodic table group IIa element or group IIIa
At least one selected from Group a elements, a metallized composition consisting essentially of oxynitride glass of aluminum and silicon and a high melting point metal powder is made into a paste, and after applying this to a required portion of the nitride ceramic body, There is provided a method for metallizing a nitride ceramic body, which comprises baking at a temperature of 1000 to 1600 ° C. in a non-oxidizing atmosphere.

As already pointed out, the present invention is characterized by using the oxynitride glass having the above composition as a glass binder for metallization. That is, by using this oxynitride glass, it becomes possible to form a metallized layer having excellent adhesion strength to a nitride ceramic body, which is completely unexpected from the metallized composition using conventional oxide glass. .

Oxynitride Glass Some of the oxynitride glass used in the metallized composition of the present invention is conventionally known as Mg-Si-Al-O-N glass or Y-Si-Al-O-N glass. ,
The fact that a part of oxygen is replaced by nitrogen is a remarkable difference from the conventional glass binder for metallization. Generally, in terms of adhesion to the nitride ceramic body, the nitrogen content in the oxynitride glass should be in the range of 2 to 19% by weight, especially 2 to 15% by weight.

In the oxynitride glass of the present invention, beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), or a combination of two or more thereof is used as the Group IIa element of the periodic table. Of these, magnesium is most preferred. In terms of adhesion to ceramic bodies, Periodic Table II
It is desirable that the group a elements, Al and Si, are in a composition range surrounded by four straight lines I, II, III and IV in FIG. 1 in the atomic ratio% based on the three components (hereinafter, including the group IIa elements. Oxynitride glass is type (i)).

That is, the oxynitride glass (i) of this type is represented by the three-component reference atomic ratio% and has the following formula Z ≧ 0.30X−0.70Y (I) Z ≧ −0.11X + 0.69Y (II) Y ≧ 5 (III) X ≧ 5 (IV) In the formula, x is the atomic ratio% of the Group IIa element of the periodic table on the basis of three components, Y is the atomic ratio of aluminum, and Z is the atomic ratio of silicon. Yes, it is assumed that X + Y + Z = 100.

It is desirable to be within the range represented by.

Incidentally, the straight lines I, II, III and IV in FIG. 1 correspond to the respective equations in the case of the equal sign in the above equation.

According to experiments conducted by the present inventors, the above straight lines I, II, III and I
It has been found that it is preferable to set the following formula as a more desirable range of the composition range surrounded by V.

That is, Z ≧ 0.37X−0.66Y (I) Z ≧ −0.06X + 0.80Y (II) Y ≧ 10 (III) X ≧ 10 (IV) In the oxynitride glass of the present invention, the periodic table is used. Group IIIa elements include scandium (Sc), yttrium (Y), lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu). , Gadolinium (Gd), Television (Td), Dysprosium (Dy), Holmium (Ho), Erbium (Er), Thulium (Tm),
Ytterbium (Yb), lutetium (Lu) and the like can be mentioned, but yttrium, lanthanum and cerium are preferable.

In terms of adhesion to the ceramic body, the Group IIIa elements of the periodic table, Al and Si, are in the composition range surrounded by the four straight lines V, VI, III and IV in FIG. It is desirable that the oxynitride glass containing a group IIIa element is referred to as type (ii) hereinafter.

That is, this type of oxynitride glass (ii) is represented by the three-component reference atomic ratio% and has the following formula: Z ≧ 0.20X + 0.09Y (V) Z ≧ −0.32X + 0.47Y (VI) Y ≧ 5. (III) X ≧ 5 (IV) In the formula, X is the atomic ratio% of the Group IIa element of the periodic table on the basis of the three components, Y is the atomic ratio of aluminum, and Z is the atomic ratio of silicon, Here, it is assumed that X + Y + Z = 100.

It is desirable to have a composition represented by

The straight lines V, VI, III and VI in FIG. 2 correspond to the respective equations in the case of the equal sign in the above equation.

According to experiments conducted by the present inventors, the straight lines V, VI, III and I
It has been found that it is preferable to set the following formula as a more desirable range of the composition range surrounded by V.

That is, Z ≧ 0.28X + 0.14Y (V) Z ≧ −0.29X + 0.59Y (VI) Y ≧ 10 (III) x ≧ 10 (IV) The composition of the oxynitride glass used in the present invention is as described above. It is obtained by blending each of the nitride and oxide raw materials or the raw material compound which becomes the oxynitride under the melting condition so as to be within the range, intimately mixing, and melting and vitrifying these components.

As a silicon raw material, silica (SiO ₂ ) or silicon nitride (Si
₃ N ₄ ) can be used, and alumina (Al ₂ O ₃ ), aluminum nitride (AlN), aluminum nitrate, or the like can be used as the aluminum raw material. Also,
As the group IIa raw material or the group IIIa raw material of the periodic table, oxides, hydroxides, nitrides, nitrates, carbonates and the like can be used. Of course, the nitride must be used as at least a part of the at least one raw material so that the above-mentioned amount of nitrogen is contained in the final glass.

In the present invention, it is desirable to use aluminum nitride as at least a part of the aluminum raw material. That is, by using aluminum nitride, more homogeneous and uniform vitrification can be achieved, and nitrogen can be effectively fixed in the final glass.

The glass used in the present invention essentially contains the above-mentioned components, but it does not exclude the inclusion of other components. For example, there are WC, ZrO _{2 and the} like, which are inevitably mixed by abrasion of grinding media such as balls as the glass composition is adjusted, and these are acceptable within 10% by weight in the entire composition. To be done. Also, for example, Al
_If a grinding medium such as ₂ O ₃ or AlN is used, the components required for the glass composition of the present invention can be mixed.

Furthermore, in the present invention, the above-mentioned raw materials were prepared in a mixing ratio within a predetermined range, heated in a non-oxidizing atmosphere, melted, and cooled. It is desirable to set this heating temperature in the temperature range of 1500 to 1900 ° C. If it is less than 1500, it does not melt easily,
When it exceeds 1900 ℃, it decomposes and volatilizes. Next, it is preferable to grind and set the particle size to 100 mesh or less in order to facilitate coating or screen printing.

The non-oxidizing atmosphere can be selected from any of a vacuum atmosphere, an inert atmosphere composed of a gas such as nitrogen or argon,
The use of nitrogen gas has the advantage that the equilibrium of glass decomposition can be controlled according to the partial pressure of nitrogen gas, and the gasification of glass can be controlled to enable efficient production.

The glass of the above-mentioned types (i) and (ii) of the present invention may be a completely amorphous glass, or one member of the component may be contained in a crystallized form depending on the composition.
For example, 40% by volume or less of the whole glass may be contained in the glass in the form of crystals such as silicon oxynitride, sialon-based compound, and N-containing silicate.

The oxynitride glass used in the present invention can also be used in the form of a mixture of type (i) and type (ii). In this case, even if the glass (i) and the glass (ii) are mixed in the form of powder to be contained in the metallized composition,
Alternatively, the glass (i) and the glass (ii) may be melt mixed in advance and used in the form of mixed glass.

Metallized composition The refractory metal powder to be dispersed and mixed in oxynitride glass is basically a powder of metal, metal silicide, nitride, and boride that does not melt or vaporize at the baking temperature, and the glass is baked. In this case, any metal, metal silicide, nitride, boride or a mixture thereof can be used, and titanium (Ti), zirconium (Zr), hafnium (Hf), vanadium (V), niobium (Nb) can be used. ), Tantalum (Ta), chromium (Cr), molybdenum (Mo), tungsten (W), and the like are metal element powders of the a series of group IV, V, and VI of the periodic table. Among these, tungsten, molybdenum, tungsten silicide, molybdenum silicide, tungsten carbide, molybdenum carbide,
Niobium silicide, tantalum silicide, or a combination of two or more of these is particularly suitable. Also, the metal powder
It is desirable to have a particle size of 100 mesh or less.

The blending ratio of glass and refractory metal powder can be varied over a fairly wide range, but in general glass powder 35 to 90
It is preferable to use a mixture of 10% to 65% by volume, especially 25 to 60% by volume of metal powder and 40% to 75% by volume.

The metallized composition of the present invention can use an auxiliary agent for imparting coatability and adhesion to a ceramic body. For example, an organic binder or an organic solvent is added to the composition of the present invention to prepare a coating composition. As the organic binder, for example, nitrocellulose or ethyl cellulose can be used, and as the organic solvent, for example, α-terpionel or butyl-calditol acetate can be used. From the viewpoint of coating property and adhesion, it is desirable to use 1 to 10% by weight of an organic binder and 10 to 20% by weight of an organic solvent based on the total amount of glass and metal.

As an example of the metallized ceramic body and its manufacturing method, FIG. 3 shows a partially longitudinal perspective view of a metallized structure by the method of the present invention.

The metallized composition fixed over the area necessary for bonding on the nitride ceramic body 1 forms a metallized portion 2 by baking, and the metallized portion 2 is plated with a nickel (Ni) layer 3 and then with a plating. A gold (Au) layer 4 is formed so that soldering is possible on the gold layer 4.

As the nitride ceramic body, silicon nitride (Si ₃ N ₄ ),
Aluminum Nitride (AlN), Sialon, Boron Nitride (B
N), titanium nitride (TiN), zirconium nitride (ZrN), etc. can be mentioned as a sintered body made of one kind or a combination of two or more kinds. Of course, these sintered bodies may contain other components, for example, oxide ceramics, etc., and may contain various sintering aids within a range not departing from the essence of the nitride ceramic body. Good.

As a sintering aid, elements of Group IIa and Group IIIa of the Periodic Table, oxides of aluminum and silicon, and aluminum nitride (AlN) are used alone or in combination. These auxiliaries form the main phase of the intergranular phase by sintering, and the intergranular phase is usually composed of an oxynitride glass or an oxynitride crystal phase obtained by crystallizing the glass.

The surface to be metallized of the ceramic body 1 formed into a predetermined shape and sintered is polished to facilitate the metallized surface. The coating composition for metallization described above is applied to this surface by silk screen printing or other application means.
This coating layer is 1000 to 1600 ℃, preferably 1300 to 1600 ℃
It suffices to heat and bake in a non-oxidizing atmosphere set within the temperature range of. The non-oxidizing atmosphere may be a vacuum atmosphere or an inert atmosphere composed of a gas such as nitrogen or argon. Particularly, when nitrogen gas is used, the equilibrium of glass decomposition can be controlled according to the partial pressure of nitrogen gas. In addition to controlling gasification of glass, bubbles are not generated in the metallized layer, and an excellent metallized ceramic body can be efficiently produced.

The thickness of the metallization layer is generally 5 to 50 mm, especially 10 to 30
It should be in the mm range.

In the present invention, when an oxynitride glass is used for forming the metallized layer, it becomes easy for the substance to move between the ceramics in contact with the glass, and the ceramic equilibrium vapor pressure can be set low due to a low temperature, so that the decomposition of the ceramic interface or It has been possible to significantly reduce the generation of bubbles. In addition, this glass has excellent wettability with the nitride ceramic body, and due to the high-concentration nitrogen component in the glass, it is possible to suppress the generation of bubbles due to the reaction as compared with the oxide glass, and as a result, the nitride of the metallized layer is suppressed. The bonding strength to the ceramic body is significantly improved.

Furthermore, oxynitride glass is superior in strength and hardness to other glasses, and has a large viscosity at high temperatures,
It also has excellent water resistance and chemical resistance. This allows
The metallized ceramic body of the present invention is suitable as a high temperature structural material.

On the obtained metallized portion, the metal to be joined is soldered as described above to form a structural material, or Au or Ni.
It can be applied to an electrical material by plating a metal having high conductivity as described above to form a conductor wiring such as a printed circuit board.

Regarding the metallized ceramic body of the present invention, a method for measuring the joint strength after soldering, which will be described later, will now be described with reference to FIG.

That is, the nitride ceramic body 1, which is the test piece S, is firmly fixed in a state in which a compressive force [thick arrow] is applied in the central direction from the left and right by the vise 8, and the hanging metal fitting 5 is mounted on the gold layer 4. It is fixed with solder 6, and a push-pull gauge (only a spring spring) 7 is attached to the upper end of the hanging metal fitting 5. In this state, the hanging metal fitting 5 is pulled up at a speed of 30 mm / minute, and the strength at the moment when the metallized portion 2 is separated from the ceramic body 1 is read by the gauge 7.

〔Example〕

(1) Nitride ceramic body A starting material for a nitride ceramic containing a sintering aid as shown in Table 1 is pulverized and mixed, molded into a desired shape, and after debinding, shown in Table 1 in a nitrogen atmosphere. After firing under such sintering conditions, the metallized surface of this sintered body was polished with a No. 250 diamond wheel to obtain test pieces (Sample Nos. A-1 to a-7). .

(2) Oxynitride glass A SiC in which hexagonal BN is coded on the inner surface by uniformly mixing raw materials consisting of compounding ingredients and compounding ratios as shown in Table 2.
It was put into a crucible. Then, the mixture was heated and melted in a nitrogen gas atmosphere under the melting conditions shown in Table 2, and then allowed to cool.

The cullet thus obtained was roughly crushed in a mortar and adjusted to have a particle size of 325 mesh or less by a vibration mill.

In Table 2, MgO, CaO and SrO are Mg (OH) ₂ and CaC, respectively.
O ₃ and SrCO ₃ were used as raw materials, respectively.

(3) Fixing and baking High melting point metal powder adjusted to a particle size of 325 mesh or less,
The oxynitride glass was mixed at a compounding ratio as shown in Table 3, and an organic binder and an organic solvent were further added to obtain a metallized composition.

4 mm of this composition on the ceramic body obtained in (1)
^A metallized portion was obtained by applying the coating in a thickness of 20 to 30 μm over the area of ² and baking in a nitrogen atmosphere under the conditions shown in Table 3.

Further, the electroless plating of Ni was applied to the metallized portion, and the suspending metal was soldered according to the method described above to measure the peel strength between the metallized portion and the ceramic body.

The measurement was performed using 20 test pieces for each test.

The results are shown in Table 3.

As is clear from Table 3, in Test Nos. 1 to 7 and 14 to 19, the peel strength is excellent, showing a high value of 51 MPa or more.

On the other hand, in Test Nos. 8 and 9, the compounding ratio of the glass and the metal was out of the desirable range of the present invention, so that the characteristic values significantly deteriorated. Excellent peel strength was not obtained because it was out of the desirable glass composition of the invention.

In addition to the high melting point metal powders other than the above examples, TaSi ₂ , TiN,
Even if TiB ₂ , ZrB ₂ and ZrN were used, the same effect as that intended by the present invention was obtained.

Furthermore, the effects of the present invention can be achieved by using elements other than those described above in Group IIa and Group IIIa of the Periodic Table and by metallizing other nitride ceramic bodies than those described above.

Further, SiO _2, MgO, based on the conventionally known high temperature metal techniques with respect to alumina ceramics with sintering aids consisting of CaO (purity 96 wt%) Mo85 wt% -Mn10 wt% -SiO ₂ 5 wt% When the metallized composition (1) was baked and the peel strength was measured according to the above, it was about 50 MPa, but it did not adhere to the nitride ceramic body and peeled off easily.

However, when the metallized composition of the present invention was used, it was possible to obtain strength higher than the adhesiveness to alumina ceramics.

〔The invention's effect〕

As described above, the use of the metallized composition of the present invention could remarkably improve the bonding strength between the nitride ceramic body and the metal. Further, this metallized composition is also excellent in water resistance and chemical resistance, and therefore suitable for a wide range of applications.

Thus, the ceramic-metal bonded body obtained according to the present invention can be used for various parts for industrial machines and electronic parts such as semiconductor packages and various ceramic substrates.

[Brief description of drawings]

FIG. 1 is a schematic diagram of a preferred oxynitride glass of Group IIa element, aluminum and silicon according to the present invention.
FIG. 2 is a diagram showing a component composition range, FIG. 2 is a diagram showing a suitable three-component composition range of an oxynitride glass of Group IIIa element of the periodic table, aluminum and silicon according to the present invention, and FIG. FIG. 4 is a partial vertical perspective view of a metallized structure according to the present invention, and FIG. 4 is a schematic view showing a strength measuring method used in an embodiment of the present invention. 1 ... Nitride ceramic body 2 ... Metallized part, 3 ... Nickel layer 4 ... Gold layer

Claims (2)

[Claims] 1. A nitride ceramic which is essentially composed of at least one element selected from Group IIa elements or Group IIIa elements of the periodic table, an oxynitride glass of aluminum and silicon, and a refractory metal powder. Body metallizing composition. 2. A paste of a metallized composition consisting essentially of an oxynitride glass of aluminum and silicon, a refractory metal powder, and at least one element selected from Group IIa or Group IIIa elements of the periodic table, A method for metallizing a nitride ceramic body, which comprises applying this to a desired portion of a nitride ceramic body and baking it at a temperature of 1000 to 1600 ° C. in a non-oxidizing atmosphere.