JPH05132363A - Zirconium boride sintered compact, its production, circuit base and its production - Google Patents

Abstract

PURPOSE:To produce a ZrB2 sintered compact excellent in denseness and electrical characteristics by making one or more kinds of periodic table VIII group metals and Mn exist in a sintered material composed mainly of ZrB2. CONSTITUTION:With powdery ZrB2, one or more kinds of powdery metals and powdery metal compounds selected from periodic table VIII group metals such as Ni, Co and Fe, Mn and compounds thereof are admixed in an amount of >=0.01wt.% on metal base. The resultant mixture is sintered in a highly reduced-pressure atmosphere of 10-10<-4>Torr or in an atmosphere of periodic table 0 group inert gas such as Ar at 1500-2000 deg.C to obtain a sintered compact composed mainly of ZrB2, excellent in high denseness and showing a low electric resistance. A circuit base is obtained by applying a paste of the above-mentioned mixture to a circuit-forming part of an uncalcined ceramic base, heat treating the base in the air at <=500 deg.C for removing, e.g. an organic binder contained in the base and the paste and subsequently calcining it in the same manner as in the above-mentioned method.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a zirconium boride sintered body and a method for producing the same, a circuit board and a method for producing the same, and more specifically, a zirconium boride sintered body used as a material for electronic parts and a method for producing the same. The present invention relates to a circuit board and a manufacturing method thereof.

[0002]

_2. Description of the Related Art Zirconium boride (ZrB ₂ ) has attracted attention as a material for electronic parts such as circuit boards because it has a low electric resistance value comparable to that of copper and excellent heat resistance. In particular, a thin film conductor made of zirconium boride formed by a vapor deposition method or a sputtering method exhibits good compactness and a low electric resistance value, and thus is expected to be applied as a circuit material such as an LSI. On the other hand, in the field of a circuit board in which a circuit is formed by a sintered body, which is a thick film conductor made of a good conductive metal such as copper, on a ceramic substrate, firing of a conductive metal sintered body for forming a circuit and ceramics In order to manufacture a circuit board by a co-firing method in which the board is fired at the same time, a heat-resistant conductive sintered body is required. Therefore, it is conceivable to form a circuit such as a circuit board with a sintered body made of zirconium boride having heat resistance.

[0003]

Since zirconium boride does not melt even at the firing temperature of a ceramic substrate such as aluminum oxide which is fired at a temperature higher than the melting temperature of copper, it has excellent heat resistance. It can be used for circuit formation of a circuit board by co-firing with a temperature-fired ceramic substrate. However, when the ceramic substrate is fired under a usual firing condition, for example, in a nitrogen atmosphere at a high temperature, the obtained zirconium boride sintered body has a low density and an extremely high electric resistance value. Therefore, when a circuit is formed on a high-temperature fired ceramic substrate by co-firing,
Conventionally, zirconium boride has not been used. In this respect, the present inventor has found that a circuit exhibiting good electric characteristics and compactness can be obtained if zirconium boride having excellent heat resistance and electric characteristics can be fired without deteriorating the characteristics of the zirconium boride. We thought that it could be obtained by co-firing with a ceramic substrate. Therefore, an object of the present invention is to provide a zirconium boride sintered body capable of exhibiting good compactness and electrical characteristics, a method for producing the same, and a circuit board having a circuit formed by the sintered body and a method for producing the same. In offer.

[0004]

As a result of repeated studies to achieve the above object, the present inventor has added nickel (Ni) or cobalt (Co) to the powder of zirconium boride and mixed it in an argon gas atmosphere. The inventors have found that a sintered body having good compactness and a low electric resistance value can be obtained by firing in the inside, and thus reached the present invention. That is, according to the present invention, a sintered body containing zirconium boride (ZrB ₂ ) as a main component contains one or more metals selected from the group consisting of metals belonging to Group 8 of the periodic table and manganese. A group consisting of a zirconium boride sintered body, a powder containing zirconium boride (ZrB ₂ ) as a main component, a metal and manganese belonging to Group 8 of the periodic table, and a metal compound thereof. Zirconium boride, characterized in that one or more metals and / or metal compounds selected from the above are added and mixed, and the mixture is fired in a highly depressurized atmosphere or in an inert gas atmosphere belonging to Group 0 of the periodic table. There is a method for manufacturing a sintered body.

Further, according to the present invention, the circuit provided on the ceramic substrate contains zirconium boride containing one or more metals selected from the group consisting of metals belonging to Group 8 of the periodic table and manganese. The circuit board is characterized by being formed of a sintered body containing (ZrB ₂ ) as a main component. Further, a powder containing zirconium boride (ZrB ₂ ) as a main component, a metal belonging to Group 8 of the periodic table and manganese, and one or more metals selected from the group consisting of metal compounds and / or The paste obtained by adding and mixing the metal compound is applied to the circuit forming portion of the unsintered ceramic substrate, and then the unsintered ceramic substrate is heat-treated in the atmosphere heated to a temperature of 500 ° C. or lower to obtain the unsintered product. After removing the fired ceramic substrate and the organic binder contained in the paste, fired in a highly decompressed atmosphere heated to a temperature of 1500 to 2000 ° C. or in an inert gas atmosphere belonging to Group 0 of the periodic table. It is also a method for manufacturing a circuit board.

In the present invention, the metal belonging to Group 8 of the Periodic Table is nickel, cobalt, iron, or the content of the metal contained in the sintered body or the powder contained in zirconium boride or added and mixed. When the added amount of the metal to be added is 0.01% by weight or more with respect to the sintered body or powder, the denseness and the electric resistance value of the sintered body can be further improved. In addition, firing of zirconium boride powder is performed at a firing temperature of 1500 to 2000 ° C. in a high-reduced pressure atmosphere of 10 to 10 ⁻⁴ Torr or an argon gas atmosphere, and as an average of zirconium boride (ZrB ₂ ) powder, By using a powder having a particle size of 2 μm or less, an oxygen content of 1.5% by weight or less, and a nitrogen content of 0.5% by weight or less, it is possible to easily obtain a sintered body having good compactness and a low electric resistance value. Obtainable.

[0007]

When the powder of zirconium boride is fired in the nitrogen atmosphere like the firing atmosphere of the conventional high temperature fired ceramic substrate, the obtained sintered body has low density and high electric resistance. When the X-ray diffraction pattern of this sintered body was investigated, the diffraction pattern peculiar to zirconium boride was hardly seen, but the diffraction pattern of zirconium nitride (ZrN) was seen. From this finding, it is speculated that zirconium boride is nitrided by the following reaction in high temperature firing in a nitrogen atmosphere. 2ZrB ₂ + 3N ₂ → 2ZrN + 4BN In this respect, in the present invention, the firing of the zirconium boride powder is performed in a highly decompressed atmosphere or in an inert gas atmosphere belonging to Group 0 of the Periodic Table and in Group 8 of the Periodic Table. By using a metal and manganese belonging to the category III, and a compound thereof as a firing aid, it is possible to prevent nitriding of zirconium boride and perform firing while maintaining the characteristics of zirconium boride as much as possible, resulting in good compactness. Thus, a zirconium boride sintered body having a low electric resistance value can be obtained. Such a sintered compact having a good compactness and a low electric resistance value can be suitably applied to a circuit of a circuit board, and when manufacturing such a circuit board, the good heat resistance of zirconium boride can be obtained. By utilizing this, it is possible to sufficiently perform low-temperature heating in the atmosphere to remove the organic binder and the like contained in the unfired ceramic substrate before high-temperature firing, so peeling or diffusion of the sintered body that forms the circuit Can be prevented.

[0008]

It is important that the zirconium boride sintered body of the present invention contains one or more metals selected from the group consisting of metals belonging to Group 8 of the periodic table and manganese. Is. Such a metal-free zirconium boride sintered body has a low density and a high electric resistance value. Here, as the metal belonging to Group 8 of the periodic table, nickel, cobalt and iron are preferable, and nickel and cobalt can be particularly preferably used. The content of such a metal in the sintered body is preferably 0.01% by weight or more. When the metal content is less than 0.01% by weight, the compactness and electric resistance of the sintered body tend to be deteriorated. If the zirconium boride contains an excessively large amount of metal, the characteristics of the sintered body tend to lose the characteristics of zirconium boride. Therefore, the upper limit of the metal content is 20% by weight, particularly 10% by weight.
It is preferably set to wt%.

Such a sintered body of the present invention is a powder containing zirconium boride as a main component, and one or more selected from the group consisting of metals and manganese belonging to Group 8 of the periodic table and metal compounds thereof. It can be obtained by adding and mixing two or more kinds of metals and / or metal compounds and firing in an atmosphere of high reduced pressure or an atmosphere of an inert gas belonging to Group 0 of the periodic table. In the present invention, it is advantageous to use a zirconium boride powder having an average particle size of 2 μm or less, an oxygen content of 1.5% by weight or less, and a nitrogen content of 0.5% by weight or less. It is possible to improve the compactness and electric resistance of the obtained sintered body. The metal added to the zirconium boride powder is preferably nickel, cobalt or iron, and the metal compound is Ni ₂ O ₃ or Ni.
O, CoO, Co ₂ O ₃ , Fe ₂ O ₃ , MnO ₂ , oxides such as NiFe ₂ O ₄ , hydroxides such as Ni (OH) ₂ , fluorides such as NiF ₂ , borides such as NiB, Specific examples include nitrides such as Fe ₄ N.
Although nitrates of metals or manganese belonging to Group 8 of the periodic table can be used, those having water content and deliquescent are difficult to handle and store.

The addition amount of such a metal and / or metal compound is 0.01% by weight or more in terms of metal with respect to the powder containing zirconium boride as a main component, whereby the compactness of the obtained sintered body is improved. And the electric resistance value can be further improved. Further, when the metal and / or the metal compound is added to the zirconium boride powder in an excessively large amount, the obtained sintered body tends to lose the characteristics of the zirconium boride, and therefore the upper limit of the metal and / or the metal compound is set. 20 in terms of metal
It is preferable to set the content to be 10% by weight, especially 10% by weight.

The firing of the powder to which the metal and / or the metal compound is added and mixed is performed in a high-reduced pressure atmosphere or an inert gas atmosphere belonging to Group 0 of the periodic table. By firing this sintered body in a high-reduced pressure atmosphere of 10 to 10 ^-4 Torr or in an argon gas atmosphere at a firing temperature of 1500 to 2000 ° C., it is possible to easily sinter with good density and good electric resistance. You can get a body. The obtained sintered body exhibits glossy white to black. The hue of the unsintered body of zirconium boride is black or blackish brown. Here, when the powder containing zirconium boride as a main component is fired in an oxidizing atmosphere or a nitrogen atmosphere, oxidation or nitridation of zirconium boride occurs, and the compactness and electric resistance value of the obtained sintered body are obtained. Both get worse. As described above, the sintered body of the present invention exhibits good compactness, low electric resistance value, and heat resistance, and thus is suitable as a circuit forming material for a ceramic circuit board. That is, by using the sintered body of the present invention as a circuit-forming material, a circuit of a circuit board can be formed by co-firing with a high-temperature firing ceramic substrate.

A circuit board using such a sintered body is a powder containing zirconium boride as a main component, a metal selected from the group consisting of metals and manganese belonging to Group 8 of the periodic table, and metal compounds thereof, or Atmosphere heated by applying a paste obtained by adding and mixing two or more kinds of metals and / or metal compounds to the circuit forming portion of the unfired ceramic substrate, and then heating the unfired ceramic substrate to a temperature of 500 ° C. or lower. After heat treatment in which the organic binder contained in the unfired ceramic substrate and paste is removed, 15
It can be obtained by firing in a highly decompressed atmosphere heated to a temperature of 00 to 2000 ° C. or in an inert gas atmosphere belonging to Group 0 of the periodic table. As described above, zirconium boride maintains a stable state even when heated at a temperature of 500 ° C. or lower in the atmosphere without causing oxidation of zirconium boride and the like. Therefore, before the high temperature firing of 1500 to 2000 ° C., the organic solvent, the organic binder and the like contained in the unfired ceramic substrate and the paste are sufficiently removed, and then the high temperature firing is performed. It is possible to prevent the sintered body forming the circuit from peeling off or diffusing.

[0013]

EXAMPLES The present invention will be described in more detail with reference to Examples. The addition amount of the metal compound shown in this example is a metal conversion value. Example 1 Zirconium boride (ZrB ₂ ) powder having an average particle size of about 1.6 μm, an oxygen content of about 1.3 wt% and a nitrogen content of 0.1 wt% or less was added with a metal or a metal compound shown in Table 1. After adding a predetermined amount and mixing with a dry mill to obtain a mixed powder, it was molded by a uniaxial press machine to obtain a cylindrical molded product having a diameter of 5 mm and a length of 20 mm. This cylindrical molded product was fired for 3 hours in a 1 Kgf / cm ² argon gas atmosphere heated to 1900 ° C. The outer diameter dimension and the weight of the obtained sintered body were measured to determine the density of the sintered body, and the electrical resistance value of the sintered body was determined by the four-terminal method. The results are also shown in Table 1. When a metal or a metal compound was fired without adding and mixing it to the zirconium boride powder, the density and electric resistance of the obtained sintered body are also shown in Table 1 as a comparative example.

[0014]

[Table 1]

The density and electric resistance of the sintered bodies of N0.1 to 13 were all good values as compared with the sintered bodies of the comparative examples which were fired without adding metal. In particular, metallic nickel (Ni) or metallic cobalt (Co) is used as the additive metal.
The sintered bodies of the levels (NO. 1 to 2, NO. 8 to 9) to which was added had a high density and a low electric resistance value.

Example 2 2-10% by weight of NiO added in No. 3-5 of Table 1 of Example 1
A sintered body was obtained by firing in the same procedure as in Example 1 except that the firing atmosphere was set to a firing high-reduced pressure atmosphere of about 5 × 10 ⁴ Torr. The amount of NiO added at each level and the density and electric resistance of the obtained sintered body are shown.

[0017]

[Table 2]

As shown in Table 2, even if the firing atmosphere was a high decompression atmosphere, the characteristics of the obtained sintered body were substantially the same as the characteristics of the sintered body obtained by firing in an argon atmosphere.
The NO.16 sintered body containing 10% by weight of NiO exhibited a silver-white luster.

Example 3 A sintered body was obtained in the same manner as in Example 1 except that the firing temperature was changed to 1800 ° C. in No. 6 of Table 1. The characteristics of the obtained sintered body are a density of 4.63 g / cm ³ and an electric resistance value of 8.8Ω.
・ It was cm. This value is almost the same as the characteristic value of the sintered body shown in No. 6 of Table 1.

Comparative Example In Example 1, 1 was used for the zirconium boride powder.
The same procedure as in Example 1 was performed except that the metal compound added by wt% and the firing atmosphere were changed as shown in Table 3. The characteristics of the obtained sintered body are also shown in Table 3. Table 3 also shows the characteristics of the sintered body obtained in the same manner as in Example 1 except that the zirconium boride powder was fired alone in a nitrogen atmosphere.

[0021]

[Table 3]

All the sintered bodies shown in Table 3 are shown in Table 1 and Table 2.
The density was lower than the density of the sintered body of N0.1 to 16 and the electric resistance value was high. NO.1 among the sintered bodies shown in Table 3
Each of the sintered bodies obtained by firing in a nitrogen atmosphere of 7 to 20 was crushed and the X-ray diffraction pattern was examined.
Almost no diffraction pattern peculiar to zirconium boride (ZrB ₂ ) was seen, and a diffraction pattern of zirconium nitride (ZrN) was observed. From this, it is understood that the zirconium boride is nitrided by firing the zirconium boride powder in the nitrogen atmosphere. In addition, although the sintered bodies of the levels of No. 21 to 23 in Table 3 have higher density and lower electric resistance than those of the sintered bodies of No. 17 to 20, This is inferior to the characteristics of the No. 1 to No. 16 sintered bodies.

Example 4 A mixed powder prepared by adding 1 wt% of metallic nickel (Ni) to the zirconium boride powder used in Example 1 was kneaded with a vehicle composed of an acrylic binder, butyl carbitol acetate, and television neol. Zirconium boride paste was used. On the other hand, an alumina sintered substrate having a purity of 99.7 wt% was prepared, and zirconium boride paste was applied by screen printing to the circuit forming portion on the alumina sintered substrate, and then heated to 1850 ° C. for 1 kg.
Firing was performed for 3 hours in an argon gas atmosphere of f / cm ² . The circuit portion composed of a sintered body of zirconium boride on an alumina sintered substrate is a dense substance that exhibits an off-white color,
No peeling of the sintered body was observed in the scratch test with tweezers. In addition, no stain or the like due to diffusion was observed.

Example 5 The zirconium boride paste used in Example 4 was screen-printed on a circuit forming portion on a green sheet made of aluminum nitride containing an acrylic binder. This green sheet is first heated in an atmospheric furnace at 380 ° C. for 3 hours to remove the organic binder and solvent contained in the green sheet and zirconium boride paste. Then, the green sheet from which the organic binder and the like were removed was fired for 5 hours in an argon gas atmosphere of 1 Kgf / cm ² heated to 1850 ° C. The obtained circuit made of the zirconium boride sintered body on the ceramic circuit board was a dense body showing a gray to silver color, and no peeling or diffusion was observed.

[0025]

According to the present invention, since a sintered body having a high density and a low electric resistance can be obtained by high temperature firing,
The sintered body of the present invention can be suitably used as an electronic component material such as a circuit forming material for a circuit board or the like.

Claims (10)

[Claims] 1. A sintered body containing zirconium boride (ZrB ₂ ) as a main component contains one or more metals selected from the group consisting of metals belonging to Group 8 of the periodic table and manganese. A zirconium boride sintered body characterized in that 2. The zirconium boride sintered body according to claim 1, wherein the metal belonging to Group 8 of the periodic table is nickel, cobalt or iron. 3. The zirconium boride sintered body according to claim 1, wherein the content of the metal contained in the sintered body is 0.01% by weight or more based on the sintered body. 4. A powder containing zirconium boride (ZrB ₂ ) as a main component, metal and manganese belonging to Group 8 of the periodic table,
And one or more metals and / or metal compounds selected from the group consisting of the metal compounds thereof, and mixed and fired in a highly decompressed atmosphere or in an inert gas atmosphere belonging to Group 0 of the periodic table. A method for producing a zirconium boride sintered body, comprising: 5. The method for producing a zirconium boride sintered body according to claim 4, wherein the metal belonging to Group 8 of the periodic table is nickel, cobalt or iron. 6. The metal or metal compound to be added to and mixed with the powder containing zirconium boride (ZrB ₂ ) as a main component is 0.01 wt% or more in terms of metal based on the powder. Item 6. A method for producing a zirconium boride sintered body according to Item 5. 7. Zirconium boride powder firing 10 times
The method for producing a zirconium boride sintered body according to claim 4, which is carried out at a firing temperature of 1500 to 2000 ° C. in a highly reduced pressure atmosphere of ^{−10 −4} Torr or an argon gas atmosphere. 8. The zirconium boride (ZrB ₂ ) powder has an average particle size of 2 μm or less, an oxygen content of 1.5% by weight or less, and a nitrogen content of 0.5% by weight or less. 6. The method for producing a zirconium boride sintered body according to claim 6 or 7. 9. A circuit provided on a ceramic substrate contains zirconium boride (ZrB ₂ ) containing one or more metals selected from the group consisting of metals belonging to Group 8 of the periodic table and manganese. A circuit board formed of a sintered body containing as a main component. 10. A powder containing zirconium boride (ZrB ₂ ) as a main component and one or more metals selected from the group consisting of metals belonging to Group 8 of the periodic table and manganese, and metal compounds thereof. And / or a paste obtained by adding and mixing a metal compound is applied to the circuit forming portion of the unfired ceramic substrate, and then the unfired ceramic substrate is heat-treated in the atmosphere heated to a temperature of 500 ° C. or lower. After removing the organic binder and the like contained in the unfired ceramic substrate and paste, in a high depressurized atmosphere heated to a temperature of 1500 to 2000 ° C. or in an inert gas atmosphere belonging to Group 0 of the periodic table. A method for manufacturing a circuit board, which comprises firing.