JPH0888453A - Ceramic circuit board and its manufacture - Google Patents

Abstract

PURPOSE: To prevent the breaking of a conductor layer by forming an insulation layer contg. aluminium nitride having a specific relative density as a main component and conductor layer contg. Au or Cu as a main component and an inorganic compd. of specified vol. and active metal of specified weight e.g. Ti as a filler. CONSTITUTION: A multilayer ceramic circuit board 1 has many laminated insulation layers 2 and conductor layers 3 are formed on the surfaces of the layers 2 in specified patterns. Via-holes 4 are formed at specified places on the layers 2 and filled with a conductor metal to connect the conductor layers 3. Each layer 2 contains aluminium nitride at a relative density of 98% or more as a main component. Each layer 3 contains Au and/or Cu as a main component and an inorganic compd. of 0.01-50vol.% and/or, at least, one active metal of 0.01-15wt.% selected among Ti, Ni and Al as a filler. Thus, the shrinkage ratios of both layers 3 and 2 can be approximated to avoid breaking the conductor layer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ceramic circuit board and a method for manufacturing the ceramic circuit board, and more particularly to a ceramic circuit board having high thermal conductivity and a method for manufacturing the ceramic circuit board.

[0002]

2. Description of the Related Art In recent years, as semiconductor elements such as ICs and LSIs have become faster and more highly integrated, the performance required for ceramic circuit boards and semiconductor packages has become stricter. For example, high thermal conductivity is required to efficiently dissipate the heat generated from the semiconductor element, and the thermal expansion coefficient is the same as that of the semiconductor element in order to minimize the risk of destruction due to thermal stress of the semiconductor element. It is required to be close. In addition, the wiring length should be shortened to reflect the recent trend of high-speed driving of semiconductor elements, the wiring material should be as low as possible in electric resistance, and the insulating material around the wiring portion should be as low in inductivity as possible. It is required to use things.

Among the ceramic materials used as insulating materials for circuit boards or packages, alumina (Al ₂ O ₃ ) ceramics have been most commonly used so far. However, although the alumina ceramics have a slightly higher thermal conductivity than conventional plastic materials and glass materials, they have a thermal conductivity of 20 W / m · K.
The thermal expansion coefficient is as low as 7 × 10 ^-1 / ° C, which is about twice the thermal expansion coefficient of silicon, 4.5 × 10 ^-6 / ° C. It cannot be said that it has sufficient characteristics to cope with the increasing demand.

Under these circumstances, an aluminum nitride (AlN) sintered body has attracted attention in place of the alumina ceramics, and its application as an insulating material for a multilayer circuit board has been studied in various fields. The AlN sintered body has a coefficient of thermal expansion of 4.0 × 10 ⁻⁶ / ° C., is almost equal to the coefficient of thermal expansion of silicon, and has a characteristic that the thermal stress of the semiconductor element can be sufficiently reduced. Furthermore, the thermal conductivity is 10
Since more than 0 W / m · K has been obtained, it is possible to sufficiently cope with an increase in the amount of heat generated due to higher integration and higher speed of semiconductor elements.

However, since the sintering temperature of an aluminum nitride sintered body is usually as high as 1700 ° C. or higher, a refractory metal such as tungsten or molybdenum must be used as a wiring material capable of simultaneous firing. There is a problem. That is, generally used wiring materials include materials having low electric resistance, such as gold, silver, copper and aluminum, and any metal material has a melting point of around 1000 ° C. (gold; 1064 ° C., silver; 961. 9
C., copper; 1085 ° C., aluminum; 660.4 ° C.). As a result, the sintering temperature should be set to 1000 for densification.
In a circuit board using an AlN sintered body as an insulating layer, which needs to be at least ℃, the wiring material cannot be applied to the simultaneous sintering technique.

The electrical resistance of the wiring material affects the delay of the signal transmission speed and the power loss. That is, if the electric resistance of the wiring material is high, a rectangular wave for transmitting a signal is blunted, the time required to reach the threshold voltage is delayed, and as a result, the signal transmission speed becomes slow. Gold, silver, copper, aluminum and the like have a low resistivity of about 2 to 3 × 10 ⁻⁶ Ω · cm, but are used as a conductor layer that can be formed on the surface of an insulating layer made of an AlN sintered body. W and Mo are 5-6 × 10 ^-6 Ω ・
cm and high resistivity. Therefore, the circuit board using the AlN sintered body as a base material has a difficulty in providing a high speed semiconductor device in the future.

Therefore, the electric resistance of gold is low,
Some attempts have been made so far to use a metal material having a low melting point for a ceramic circuit board having an insulating layer containing AlN as a main component, which has good thermal conductivity. The solution in such cases is to reduce the sintering temperature of the ceramic material. For example, JP-A 1-219066, JP-A-2-196066 and JP-A-2-221162.
The glass powder and the inorganic material powder are mixed with AlN powder having good thermal conductivity, and the sintering temperature is 800 ° C to 1000 ° C.
It is disclosed to reduce to a certain degree. These methods allow the use of wiring materials such as gold. However, in the circuit board manufactured by such a method, the insulating layer containing AlN as a main component has a thermal conductivity of about 10 to 20 W / m · K, and has a natural conductivity of 1%.
As a result, the thermal conductivity is significantly reduced as compared with the thermal conductivity of 00 W / m · K or more.

On the other hand, in JP-A-2-197189, attention is paid to the fact that the wiring material has low wettability with AlN.
A method of manufacturing a multilayer circuit board in which any of gold, silver, and copper is formed as an internal wiring between insulating layers containing N as a main component is disclosed. However, according to this method, since the molded body containing AlN as a main component is sintered at a high temperature of 1700 ° C. or higher, the components in the molded body, particularly the sintering aid, are mixed into the wiring material, resulting in the wiring material. Causes a problem that the electric resistance of the device becomes high. Particularly, when gold is used as the wiring material, the increase in the electric resistance becomes remarkable.

Further, in order to reduce the size and increase the degree of integration, it is desired in the future to make the line width of the conductor layer (circuit pattern) as small as possible. When the line width of the circuit pattern is made fine, the conductor metal is not improved and the above-mentioned Japanese Patent Application Laid-Open No. HEI-2 is used.
When a conductor material and an insulating material are co-sintered at a high temperature as disclosed in Japanese Patent Application Laid-Open No. 197189, when the conductor metal becomes a melt, the conductor metal is likely to be spherical so as to reduce the surface energy. It may lead to disconnection, and when applied as a multilayer ceramic circuit board, it leads to a decrease in reliability and is fatal.

[0010]

SUMMARY OF THE INVENTION An object of the present invention is to make an insulating layer containing AlN as a main component having high thermal conductivity and a metal having a low electric resistance and a low melting point, such as gold or copper, as a main component. And a ceramic circuit board having good characteristics without defects such as disconnection, peeling, and oxidation of the conductor layer, and a ceramic circuit having excellent characteristics described above by simultaneous sintering at low temperature. It is intended to provide a method for manufacturing a substrate.

[0011]

The ceramic circuit board according to the present invention has a relative density of 98% or more and is made of Al.
At least one of an insulating layer containing N as a main component, gold and / or copper as a main component, and 0.01 to 50% by volume of an inorganic compound and / or 0.01 to 15% by weight of titanium, nickel, and aluminum. And a conductor layer containing a kind of active metal as a filler.

As the inorganic compound as the filler,
Ceramic powder stable up to firing temperature, eg AlN, S
Examples thereof include i ₃ N ₄ , ZrO ₂ , MgO, Al ₂ O _{3 and the} like. In particular, it is preferable to use, as the inorganic compound, the same components (AlN powder, sintering aid, etc.) as the insulating layer containing AlN as the main component. By using such an inorganic compound filler, the contraction rates of the conductor layer and the insulating layer can be approximated, and peeling of the conductor layer, disconnection, cracking of the insulating layer, warpage, etc. can be effectively prevented.

The amount of the inorganic compound to be added is defined as follows.
The reason is as follows. If the blending amount of the filler is less than 0.01% by volume, the blending effect cannot be sufficiently achieved, and it becomes impossible to prevent the conductor layer from breaking. On the other hand, when the content of the filler exceeds 50% by volume, the resistivity of the conductor layer increases rapidly, which leads to signal delay. A more preferable blending amount of the inorganic compound is 0.0
It is 5 to 40% by volume.

At least one active metal selected from titanium (Ti), nickel (Ni), and aluminum (Al) as the filler is firmly bound to AlN, which is the main component of the insulating layer, to form the inorganic compound. Similar to the filler, it has a function of preventing the molten conductor metal from spheroidizing or flowing out. The reason for defining the compounding amount of such an active metal is as follows. If the amount of the active metal compounded is less than 0.01% by weight, the above-mentioned effect is remarkably deteriorated and the conductor layer is broken. On the other hand, if the content of the active metal exceeds 15% by weight, the type of active metal (A
There is a problem that the melting point of the conductor metal (gold, copper) is drastically lowered depending on the content of l or Ti) to flow out. A more preferable blending amount of the active metal is 0.05 to 12% by weight.

In addition to gold and copper, tungsten and molybdenum may be mixed in the conductor layer in an amount of 20% by volume or less. If the content of such a high melting point metal exceeds 20% by volume, the resistivity becomes high, which may cause a signal delay.

The ceramic circuit board (multilayer ceramic circuit board) according to the present invention has, for example, the structure shown in FIG. The multilayer ceramic circuit board 1 is formed by laminating a plurality of insulating layers 2 containing AlN as a main component. On the surface of these insulating layers 2, a conductor layer 3 of a predetermined pattern containing at least one selected from gold and copper as a main component is formed. Further, a via hole 4 is formed at a predetermined position of the insulating layer 2, and the conductive metal filled in the via hole 4 electrically connects the conductive layer 3 formed on each surface of the insulating layer 2. ing.

According to the present invention as described above, an insulating layer containing AlN having a high thermal conductivity as a main component and a conductor layer containing a low resistance metal such as copper or gold as a main component are provided, and It is possible to provide a ceramic circuit board having good characteristics without defects such as disconnection, peeling and oxidation of the conductor layer.

The ceramic circuit board according to the present invention, for example, the multilayer ceramic circuit board as described above, is manufactured by the following method. (First step) After adding a sintering aid to AlN powder and thoroughly mixing it, a binder is added to this mixed powder and kneaded and dispersed in a predetermined solvent to prepare a predetermined viscosity. Granulation,
Perform sizing. Subsequently, the obtained suspension is formed into a sheet by, for example, a doctor blade method, and dried at a temperature of about 200 ° C. to form a green sheet. At this time, it is desirable that the conductor metal is formed at a high density in order to minimize the penetration of the conductor metal into the insulating layer containing AlN as a main component in the sintering step. Subsequently, a plurality of via holes for interlayer connection are formed at predetermined positions on the green sheet.

As the AlN powder, virtually any available powder can be used, but the average primary particle diameter is 0.03 to 3.5 μm and the amount of oxygen impurities is 0 due to sinterability and thermal conductivity. 2 to 3.5% by weight, more preferably, the average primary particle diameter is 0.05 to 1.5 μm, and the amount of impurity oxygen is 0.
It is desirable to use 3 to 3% by weight of powder. The Al
When the average primary particle size of N powder is less than 0.03 μm, it is very difficult to form a sheet, and the finally obtained Al
In the insulating layer containing N as a main component, the amount of impurity oxygen increases, which may make it impossible to obtain high thermal conductivity. Further, since the sheet density at the time of molding decreases, the shrinkage rate at the time of sintering becomes large, and it tends to be difficult to control the position of the conductor layer on the sheet surface. Furthermore, it becomes difficult to match the contraction rate with the conductor layer, and
There arises a problem that a gap is formed between the insulating layer containing 1N as a main component. On the other hand, when the average particle diameter of the AlN powder exceeds 3.5 μm, the sinterability is remarkably reduced, and it becomes difficult to form an insulating layer made of a sufficiently dense sintered body. On the other hand, if the amount of impurity oxygen is less than 0.2% by weight, the sinterability is deteriorated and there is a possibility that a sufficiently dense insulating layer containing AlN as a main component cannot be formed.

The sintering aid is at least one selected from the group consisting of rare earth oxides, alkaline earth oxides, and compounds which become rare earth oxides or alkaline earth oxides in the sintering process.
Seeds can be used. Examples of the compound that becomes an oxide in the sintering process include carbonate, oxalate, nitrate, and alkoxide. Further, the addition amount of the sintering aid is preferably 0.05 to 15% by weight as the total amount of all the sintering aids. If the addition amount of the sintering aid is less than 0.05% by weight, it may not effectively act on the sintering of AlN,
Further, it becomes difficult to form an insulating layer containing AlN having a high thermal conductivity as a main component. On the other hand, the addition amount of the sintering aid is 1
AlN having a similar high thermal conductivity even if it exceeds 5% by weight
It becomes difficult to form an insulating layer containing as a main component. A more preferable amount of the sintering aid added is 0.2 to 10% by weight.

In addition to the sintering aid, alumina (Al) is added to the mixed powder for the purpose of improving the sinterability of AlN.
₂ O ₃ ), aluminum compounds such as AlF ₃ , boron oxide (B ₂ O ₃ ), phosphorus compounds for surface improvement, silicon oxide (SiO ₂ ) effective for increasing mechanical strength, silicon nitride (Si ₃ N ₄ ) or the like is allowed to be blended in the range of 1% by weight or less based on the AlN powder. Furthermore, for coloring and strengthening, Ti, W, Mo, Ta, Nb,
Oxides, carbides, fluorides, carbonates, oxalates, and nitrates of transition metals such as Mn may be contained in the mixed powder in the range of 0.05 to 1% by weight in terms of transition metal.

As the binder added to the mixed powder, for example, an acrylic binder or a PVB binder can be used. As the solvent in which the mixed powder and the binder are dispersed, for example, alcohols such as n-butanol, methyl isobutyl, toluene, xylene and the like can be used.

As a method of forming the via hole, for example, a mechanical method using a punch, a die, a punching machine, a laser processing method or the like can be adopted. (Second step) 0.01 to 50% by volume of an inorganic compound and / or 0.01 to 15% by weight of titanium and nickel in at least one conductive metal powder selected from copper and gold.
At least one active metal of aluminum is added as a filler, and a binder and a solvent are further added and kneaded to prepare a conductor paste. Continuing,
This conductor paste is printed on the surface of the AlN green sheet produced in the first step by a screen printing method or the like, and the conductor paste is filled in the via holes. Subsequently, these green sheets are aligned with each other at the via holes and stacked by thermocompression bonding to produce a laminate.

The conductive metal powder has an average particle size of 0.1 to 0.1.
It is preferable to have 3.0 μm. When the average particle diameter of the conductive metal powder is less than 0.1 μm, handling is not easy and it becomes difficult to form a paste, and the obtained conductor paste may not be printed on the green sheet. On the other hand, the average particle diameter of the conductive metal powder is 3.0 μm.
If it exceeds m, the dispersibility in the solvent deteriorates.

As the inorganic compound as the filler,
The materials mentioned above are selected. By adding such an inorganic compound, the surface energy of the conductor metal melted at the time of sintering at a high temperature is reduced to be spherical,
It is possible to prevent the viscosity from decreasing and easily move, and as a result, it is possible to prevent the conductor layer (circuit pattern) from breaking, the conductor metal from flowing out, and the like.

(Third Step) The green sheet on which the conductor paste layer is formed is set in, for example, an AlN setter, degreased in a non-oxidizing atmosphere such as nitrogen, and then preferably in a non-oxidizing atmosphere, more preferably 1 Sintering is performed at a temperature of 1800 ° C. or lower in a non-oxidizing atmosphere at atmospheric pressure or higher. Then, if necessary, surface grinding, polishing, thin film circuit formation, plating,
By performing pin formation or the like, a multilayer ceramic circuit board including an insulating layer containing AlN as a main component and a conductor layer containing copper and / or gold as a main component is manufactured.

Another ceramic circuit board according to the present invention has aluminum nitride particles having an average particle size of 5 μm or less, and contains a rare earth compound and / or an alkaline earth compound as an auxiliary phase in an amount of 0.05 to 15 in terms of oxide. weight%
And a ceramic insulating layer made of an aluminum nitride sintered body containing at least one component selected from halogen, boron and manganese (excluding a mixture of halogen and boron), and gold and And / or a conductor layer containing copper as a main component.

According to the present invention as described above, an insulating layer containing AlN as a main component, which has a high thermal conductivity, a high density and a high mechanical strength, and a low resistance conductor layer such as copper or gold are further provided. It is possible to provide a ceramic circuit board having good characteristics without defects such as disconnection, peeling and oxidation of the conductor layer.

Another ceramic circuit board according to the present invention, such as a multilayer ceramic circuit board as described above, is manufactured by the following method. (First step) After adding a sintering aid to AlN powder and thoroughly mixing it, a binder is added to this mixed powder and kneaded and dispersed in a predetermined solvent to prepare a predetermined viscosity. Granulation,
Perform sizing. Subsequently, the obtained suspension is formed into a sheet by, for example, a doctor blade method, and dried at a temperature of about 200 ° C. to form a green sheet. At this time, in order to suppress the penetration of the conductive metal into the AlN insulating layer at the time of firing to the minimum, it is desirable to perform high density molding.
Subsequently, a plurality of via holes for interlayer connection are formed at predetermined positions on the green sheet.

As the AlN powder, the same powder as that described in the method for manufacturing a circuit board described above is used. Especially in order to reduce the temperature of the co-sintering process, the average primary particle size is set to 0.
It is preferable to use AlN powder having a particle size of 03 to 0.5 μm and an impurity oxygen amount of 1.0 to 3.5% by weight.

The following materials are used as the sintering aid. (A) At least one selected from the group consisting of 0.05 to 15% by weight of oxides of rare earth oxides, alkaline earth oxides, and compounds that become oxides by sintering, and 0.05 to 5% by weight of boron simple substance. Or a boron compound and / or 0.
A sintering aid consisting of 05 to 5% by weight of manganese (Mn) alone or a manganese compound.

(B) The rare earth elements (Y, Sc, La, etc.) mixed in a total amount of 0.1 to 15% by weight of the sintering aid.
Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, H
o, Er, Tm, Yb, Lu, etc. halogen (F, C
Sintering aid comprising at least one selected from the group consisting of (1, l, Br, I, etc.), acid halides, and halides of alkaline earth metals (Ca, Sr, Ba, etc.).

In the sintering aid (b), in order to improve the cleanliness of the surface, part of the halide or acid halide is an oxide of the rare earth element or alkaline earth metal,
Alternatively, it is permissible to replace with a compound that becomes these oxides by sintering, for example, to replace a part of the added amount of YF ₃ with Y ₂ O ₃ or a part of CaF ₂ with CaO.

In the sintering aid of the above (b), the above (a)
The manganese or manganese compound effective for sintering at a low temperature is allowed to be blended in the range of 0.05 to 5% by weight, like the above-mentioned sintering aid.

The firing aids (a) and (b) have a particle size as fine as possible, for example 0.3, for the purpose of low temperature sintering.
It is preferably μm or less. With any of the sintering aids (a) and (b), it is possible to reduce the sintering temperature in the third step described below to 1700 ° C. or lower, more preferably 1600 ° C. or lower. Become. In such low temperature sintering, it is possible to form a dense insulating layer containing AlN as a main component.

In addition to the sintering aid, alumina (Al) is added to the mixed powder for the purpose of improving the sinterability of AlN.
1% by weight of ₂ O ₃ ), aluminum compounds such as AlF ₃ , phosphorus compounds for surface improvement, silicon oxide (SiO ₂ ), silicon nitride (Si ₃ N ₄ ) effective for increasing mechanical strength, etc. It is allowed to contain within the following range. Furthermore, for coloring and strengthening, Ti, W, Mo, T
a, Nb, Mn and other transition metal oxides, carbides, fluorides, carbonates, oxalates, and nitrates are contained in the mixed powder in the range of 0.05 to 1% by weight in terms of transition metal. Good.

The density of the molded body obtained by the above-mentioned molding step is desirably made as high as possible by improving the addition amount and type of the binder in consideration of the sintering at low temperature, and more preferably with respect to the theoretical density. The relative density is 55% or more.

(Second Step) A conductive paste is prepared by adding a binder and a solvent to at least one conductive metal powder selected from copper and gold and kneading. Next, this conductor paste was used for the AlN produced in the first step.
The surface of the green sheet is printed by a screen printing method or the like, and the via holes are filled with the conductor paste. Subsequently, these green sheets are aligned with each other at the via holes and stacked by thermocompression bonding to produce a laminate.

The conductive paste may contain 0.01 to 50% by volume of the inorganic compound as the above-mentioned filler and 0.01 to 15% by weight of the active metal. In addition to copper and gold, tungsten or molybdenum may be added to the conductor paste in a range of up to 20% by volume. If it exceeds 20% by volume, the resistivity becomes high, which may cause a signal delay.

(Third step) The green sheet on which the conductor paste layer is formed is set in, for example, an AlN setter, degreased in a non-oxidizing atmosphere such as nitrogen, and then preferably in a non-oxidizing atmosphere, more preferably 1 In a non-oxidizing atmosphere at atmospheric pressure or higher, 1700 ° C. or lower, more preferably 1300 to 16
Sinter in the range of 00 ° C. Subsequently, if necessary, grinding, polishing, thin film circuit formation, plating, pin formation, etc. on the surface are performed to form an insulating layer containing AlN as a main component,
A multilayer ceramic circuit board having a conductor layer containing copper and / or gold as a main component is manufactured.

The sintering temperature is defined for the following reason. When the sintering temperature is lower than 1300 ° C., the time required to sufficiently densify the insulating layer formed from the green sheet becomes long. On the other hand, if the sintering temperature exceeds 1700 ° C., the formed conductor layer may be broken if a filler such as an inorganic compound or an active metal is not added to the conductor paste. Further, when the above-mentioned (b) containing a halide is used as the sintering aid, the migration of the grain boundary phase to the surface of the insulating layer containing AlN as a main component becomes vigorous, resulting in smoothness and purification of the surface. Sex is impaired.

By performing the sintering at such a temperature of 1700 ° C. or less, the grain size of the obtained insulating layer containing AlN as a main component becomes as small as 5 μm or less. Mechanical strength is improved as compared with the insulating layer containing AlN as a main component.

Further, the method for producing a ceramic circuit board according to the present invention comprises a step of producing a compact from a powder mixture containing AlN powder and a sintering aid, and at least the surface of the compact from gold, silver and copper. A step of forming a conductor paste layer by applying a conductor paste containing at least one selected from the above in a pattern, and the molded body in a non-oxidizing atmosphere.
Hot-press sintering at 10 MPa or more at 100 ° C. or less is performed on the insulating layer containing aluminum nitride as a main component to form Au,
And a step of forming a patterned conductor layer containing at least one selected from Ag and Cu as a main component.

The method of manufacturing the ceramic circuit board according to the present invention will be described in detail below. First, a mixed powder containing an AlN powder and a sintering aid is sufficiently kneaded with an organic solvent together with a binder to crush and disperse the powder to prepare a slurry having a predetermined viscosity. Subsequently, the slurry is formed into a sheet by the doctor blade method, and then dried by heating to remove the solvent to obtain a green sheet. Subsequently, a conductive paste layer containing at least one selected from Au, Ag, and Cu as a main component is formed on at least the surface of the green sheet by, for example, screen printing to form a patterned conductive paste layer. Then, the green sheet on which the conductor paste layer is formed is heated in a non-oxidizing atmosphere to remove the binder in the conductive paste, and then in a non-oxidizing atmosphere.
A ceramic circuit board is manufactured by hot press sintering under a pressure of 00 ° C. or lower and 10 MPa or higher. After sintering, trimming, thin-film or thick-film circuit formation, and external electrodes can be formed as necessary.

The AlN powder has an average primary particle size of 0.
02-0.1 μm, more preferably 0.04-0.09
It is preferable that μm and the amount of impurity oxygen are 1.0 to 5.0% by weight. The average primary particle diameter of the AlN powder is 0.0
If it is less than 2 μm, it may be difficult to mold the mixed powder containing the sintering aid as an additive. On the other hand, if the average primary particle diameter of the AlN powder exceeds 0.1 μm, the sinterability may decrease. Also, if the amount of impurity oxygen is less than 1.0% by weight, Al may be added during the handling stage of mixing and molding before sintering.
There is a possibility that N may deteriorate or sintering may not proceed sufficiently. On the other hand, when the amount of impurity oxygen exceeds 5.0% by weight, A
There is a possibility that the thermal conductivity of the insulating layer containing 1N as a main component may decrease.

The sintering aid has a composition containing an alkaline earth metal, a rare earth element and at least one selected from compounds such as alkali metals, phosphorus, boron and aluminum.

The alkaline earth metal or rare earth element compound is added as a powder or a liquid. These compounds are, for example, oxides, carbides, fluorides, oxyfluorides,
Used in the form of carbonates, oxalates, nitrates, alkoxides. Further, various combinations are possible, such as adding the compound of the alkaline earth metal or the rare earth element and then adding the nitrate of the rare earth after dissolving it in alcohol. When added as a powder, the average particle size is 1.0 μm or less,
More preferably, the thickness is 0.6 μm or less.
The alkaline earth metal is selected from Ca, Ba and Sr, and the rare earth element is selected from Sc, Y and lanthanum series elements. It is desirable that the compound of the alkaline earth metal or the rare earth element is contained in the mixed powder in an amount of 3 to 17% by weight.

Examples of the alkali metal compound include oxides and halides of alkali metals such as Na ₂ CO ₃ , NaF and NaCl, or compounds that change into these compounds during firing. The alkali metal compound is preferably contained in the mixed powder in an amount of 0.01 to 2.0% by weight.

[0049] As the boron compound include compounds that change, for example, B ₂ O ₃ or firing middle B ₂ O _3. Further, borate of alkali metal such as Na ₂ B ₄ O ₇ is also used. The boron compound is preferably contained in the mixed powder in an amount of 0.01 to 2.0% by weight.

As the phosphorus compound, phosphides, phosphates, hydrogen phosphates and the like can be used. Examples of the phosphide include Ca ₃ P ₂ and AlP. Examples of the phosphate include Ca (PO ₄ ) ₂ and Ba (PO
₄ ) ₂ , Sr (PO ₄ ) ₂ ; YPO ₄ , LaPO ₄ , C
ePO ₄ , GdPO ₄ , YbPO ₄ ; Li ₃ PO ₄ , N
_{a 3 PO 4, K 3 PO} 4 and the like. Examples of the hydrogen phosphate include Ca (H ₂ PO ₄ ) ₂ , CaHPO ₄ ,
Ba (H ₂ PO ₄ ) ₂ , BaHPO ₄ , Sr (H ₂ PO
₄ ) ₂ , SrHPO _4, LiH ₂ PO ₄ , Li ₂ HPO
₄ , NaH ₂ PO ₄ , Na ₂ HPO ₄ , KH ₂ PO ₄ ,
K ₂ HPO ₄ ; Y ₃ (PO ₄ ) ₄ , La ₃ (PO ₄ )
₄ , Ce ₃ (PO ₄ ) ₄ , Gd ₃ (PO ₄ ) _{4 and the} like. As the phosphorus oxide, for example, P ₂ O _{5 and the} like, and as the other phosphates, aluminum phosphate (AlPO ₄ or Al (PO ₃ ) ₃ ) and aluminum hydrogen phosphate (Al ₂
(HPO ₄ ) ₃ ) and the like. These phosphorus compounds are preferably contained in the mixed powder in an amount of 0.01 to 2.0% by weight in terms of anhydride.

In the mixed powder, in addition to the various additives described above, IV such as SiO ₂ , Si ₃ N ₄ , SiC or GeO ₂ is added.
B-group element oxides or nitrides, carbides, Al ₂ O
It is permissible to contain oxides or halides of IIIb group elements such as ₃ , AlF ₃ and GaF ₃ in an amount of 1% by weight or less. Further, it is allowed to contain a transition metal compound in the mixed powder mainly for coloring or blackening. Examples of the transition metal compound include Ti, Nb, Z
R, Ta, W, Mo, Cr, Fe, Co, Ni oxides, nitrides, carbides, oxycarbides, oxynitrides and the like can be added. In particular, it is desirable that the sintered body has conductivity. Examples of such transition metal compounds having conductivity include metals such as W and Mo, Zr, Ti, Nb,
A nitride or a carbide of an element selected from Ta can be mentioned. The addition amount of these is preferably 1.5% by weight or less.

The binder added when preparing the slurry is, for example, acrylic, methacrylic, P
Examples include VB type. The amount of these binders added is
It depends on the particle size of the AlN powder used, but is 2 to 12% by weight, more preferably 4 to 1% by weight based on the mixed powder.
0% by weight. Examples of the solvent in which the binder is dispersed include alcohols such as n-butanol, methyl isobutyl, toluene and xylene.

As the binder for the conductor paste,
In addition to the binder used in the molded body, a cellulose-based binder such as ethyl cellulose or nitrocellulose,
Plasticizer such as dioctyl phthalate, α- or γ-terpineol, MIBK (methyl isobutyl ketone),
Solvents such as MEK (methyl ethyl ketone) and carbenol are added at appropriate times. The amount of binder added is 2 to 7% by weight
Is desirable.

In the conductor paste, AlN powder or AlN powder is used for the purpose of preventing vaporization of components and bleeding of components into the insulating layer, and matching shrinkage rates of the conductor layer and the insulating layer.
It is preferable to add the mixture of N powder and the sintering aid in the range of 0.01 to 50% by volume, and more preferably 0.05 to 40% by volume.

In the conductor paste, Au, Ag, C
In addition to u, addition of tungsten or molybdenum in a range of up to 20% by volume is allowed. If it exceeds 20% by volume, the resistivity becomes high, which may cause a signal delay.

For removing the binder from the molded body coated with the conductor paste, the maximum temperature is 1000 in a non-oxidizing atmosphere.
It is preferable to carry out at a temperature of ℃ or less. Here, the non-oxidizing atmosphere means that nitrogen and / or argon, or a part of these contains hydrogen, carbon gas, or the like. In addition,
When the conductor paste does not contain a conductor metal such as tungsten or molybdenum, it is possible to remove the binder by heating in an atmosphere containing oxygen. In this case, it is desirable that the maximum heating temperature be up to 500 ° C.

The hot-press sintering of the molded body after the binder removal is carried out by non-oxidizing atmosphere consisting of nitrogen and / or argon and a mixed gas of which hydrogen and carbon dioxide are partially contained, AlN, BN and carbon. It is preferable to carry out in a sintering container selected from the following in a sintering furnace equipped with a heater selected from carbon, tungsten, molybdenum and the like. The amount of oxygen in the atmosphere is acceptable if it is within 100 ppm. In the sintering schedule, the temperature can be raised monotonically to the maximum temperature, but the temperature can also be raised stepwise to the maximum temperature if necessary.

In the multilayer ceramic circuit board, via holes are previously formed in the green sheets in order to obtain electrical connection between layers, the conductive paste is filled in the via holes by, for example, a press-fitting method, and then the green sheets are laminated. The laminate is manufactured by subjecting it to binder removal processing and hot press sintering.

According to the present invention as described above, an insulating layer containing AlN as a main component, which is dense and has high thermal conductivity and high mechanical strength, is formed by simultaneous low-temperature hot press sintering at 1100 ° C. or lower, Au, Ag, and Equipped with a low resistance conductor layer such as Cu,
Moreover, it is possible to manufacture a ceramic circuit board having good characteristics without defects such as disconnection, peeling, and oxidation of the conductor layer.

[0060]

EXAMPLES The present invention will be described in more detail below with reference to examples. Note that these examples are described for the purpose of facilitating the understanding of the present invention and do not limit the present invention.

(Example 1) AlN powder having an average primary particle size of 0.6 μm and an impurity oxygen content of 1.0% by weight was mixed with 3% by weight of Y ₂ O ₃ as a sintering aid and WO ₃ for coloring. Add 0.3 wt% of each in terms of W and use a ball mill to n-
Wet mixed in butanol. This mixed powder was dispersed in an organic solvent together with an organic binder, and the obtained slurry was formed into a sheet by a doctor blade method to prepare a plurality of green sheets. Subsequently, a plurality of via holes for interlayer connection were formed at predetermined positions of the obtained green sheet by using a punching machine.

On the other hand, 80% by volume of copper powder having an average particle size of 0.5 μm and 20% by volume of a filler mixed powder consisting of 97% by weight of AlN powder and ₃ % by weight of Y ₂ O ₃ powder having an average particle size of 0.6 μm. Was dispersed in an organic solvent together with an organic binder to prepare a conductor paste.

Next, the conductor paste was printed on the green sheet by a screen printing method to form a conductor paste layer on the surface of the sheet, and the via holes were filled with the conductor paste. Subsequently, a plurality of green sheets on which the conductor pate layer was formed were aligned by the via holes, overlapped with each other, and heated and pressed to produce a laminate. Continuing, the laminated body in a nitrogen atmosphere,
After degreasing at 700 ℃, 1750 ℃ in nitrogen atmosphere of 1 atm
By sintering for 3 hours, a multilayer ceramic circuit board having the structure shown in FIG. 1 was manufactured.

The obtained circuit board was cut in the thickness direction and the internal fine structure was observed. As a result, the insulating layer containing AlN as a main component was sufficiently densified, no pores were observed, and no defects such as voids were observed in the conductor layer.
In addition, no particular warpage or deformation was observed in the appearance of the circuit board.

Further, the insulating layer containing AlN as a main component constituting the multilayer ceramic circuit board has a resistivity of 10 ¹¹ Ω.
cm or more, the relative dielectric constant was 8.7, the dielectric loss was 10 ⁻³ or less (both under the condition of 1 MHz), and the thermal conductivity was 170 W · m ⁻¹ · K ⁻¹ . The conductor layer forming the circuit board had an extremely low resistivity of 6.5 × 10 ⁻⁶ Ω · cm.

(Comparative Example 1) Al having the same composition as in Example 1
An N green sheet was produced, and a conductor paste containing copper containing no filler, a binder, and an organic solvent was further produced. Subsequently, the conductor paste is screen-printed on the green sheet to produce a green sheet having a conductor paste layer, and then binder removal processing and sintering are performed in the same manner as in Example 1 to manufacture a multilayer ceramic circuit board. did.

The obtained circuit board was cut in the thickness direction and the internal fine structure was observed. As a result, the insulating layer containing AlN as a main component was sufficiently densified and no pores were observed. However, some of the conductor layers, particularly the conductor layer having a width of 50 μm or less, were found to have voids in some places, and it was recognized that the conductor layers were broken.

Example 2 CaO was added to AlN powder having an average primary particle size of 0.3 μm and an impurity oxygen content of 1.5% by weight with CaO.
Wt% was added and wet mixed in n-butanol using a ball mill. This mixed powder was dispersed in an organic solvent together with an organic binder, and the obtained slurry was formed into a sheet by a doctor blade method to prepare a plurality of green sheets. Subsequently, a plurality of via holes for interlayer connection were formed at predetermined positions of the green sheet by using a punching machine.

On the other hand, 95% by weight of gold powder having an average particle size of 1.0 μm and 5% by weight of Ti powder having an average particle size of 0.6 μm were dispersed in an organic solvent together with an organic binder to prepare a conductor paste.

Next, the conductor paste was printed on the green sheet by a screen printing method to form a conductor paste layer on the surface of the sheet, and the via holes were filled with the conductor paste. Subsequently, a plurality of green sheets on which the conductor paste layer was formed were aligned with each other in the via holes and overlapped with each other, and hot pressed to produce a laminate. Continuously, after degreasing the laminated body at 700 ° C. in a nitrogen atmosphere, in a nitrogen atmosphere of 1 atm,
A multilayer ceramic circuit board having the structure shown in FIG. 1 was manufactured by sintering at 1700 ° C. for 6 hours.

The obtained circuit board was cut in the thickness direction and the internal microstructure was observed. As a result, the insulating layer containing AlN as a main component was sufficiently densified, no pores were observed, and no defects such as voids were observed in the conductor layer. In addition, no particular warpage or deformation was observed in the appearance of the circuit board.

Further, the insulating layer containing AlN as a main component which constitutes the multilayer ceramic circuit board has a resistivity of 10 ¹¹ Ω.
cm, the relative dielectric constant was 9.0, the dielectric loss was 10 ⁻³ or less (both under the condition of 1 MHz), and the thermal conductivity was 160 W · m ⁻¹ · K ⁻¹ . The conductor layer forming the circuit board had an extremely low resistivity of 5.6 × 10 ⁻⁶ Ω · cm.

Comparative Example 2 Al having the same composition as in Example 2
N green sheet is made and gold containing no Ti,
A conductor paste made of a binder and an organic solvent was prepared. Subsequently, the conductor paste was screen-printed on the green sheet to prepare a green sheet having a conductor paste layer, and then the binder removal treatment and the sintering were performed in the same manner as in Example 2 to manufacture a multilayer ceramic circuit board. did.

The obtained circuit board was cut in the thickness direction and the internal fine structure was observed. As a result, the insulating layer containing AlN as a main component was sufficiently densified and no pores were observed. However, some of the conductor layers, particularly the conductor layer having a width of 50 μm or less, were found to have voids in some places, and it was recognized that the conductor layers were broken.

(Examples 3 to 8) The same as Example 1 except that the mixed powder for the insulating layer and the conductive paste having the compositions shown in Table 1 below were used and sintered under the conditions shown in Table 1 below. Six types of multilayer ceramic circuit boards were manufactured by the method. The density and thermal conductivity of the insulating layer, the resistivity of the conductive layer, and the appearance of each of the obtained circuit boards were examined. The results are shown in Table 2 below.

[0076]

[Table 1]

[0077]

[Table 2]

As is clear from Table 2, Examples 3 to 8
It can be seen that each of the multilayer ceramic circuit boards of 1) has excellent characteristics and good appearance. (Example 9) Average particle size 0.6 μm, impurity oxygen amount 1.3
97% by weight of AlN powder, and YF as a sintering aid
₃ % by weight of ₃ powders were added and wet mixed in n-butanol using a ball mill. This mixed powder was dispersed in an organic solvent together with an organic binder, and the obtained slurry was formed into a sheet by a doctor blade method to prepare a plurality of green sheets. Subsequently, a plurality of via holes for interlayer connection were formed at predetermined positions of the obtained green sheet by a punching machine.

On the other hand, gold powder having an average particle diameter of 0.7 μm was dispersed in an organic solvent together with an organic binder to prepare a conductor paste. Then, the conductor paste was printed on the green sheet by a screen printing method to form a conductor paste layer on the surface of the sheet, and the via holes were filled with the conductor paste. Subsequently, a plurality of green sheets on which the conductor paste layer was formed were aligned and overlapped with each other by via holes, and heated and pressed to produce a laminate. Continuously, after degreasing the laminated body at 700 ° C. in a nitrogen atmosphere, in a nitrogen atmosphere of 1.2 atm, 1
A multilayer ceramic circuit board having the structure shown in FIG. 1 was manufactured by sintering at 540 ° C. for 6 hours.

The obtained circuit board was cut in the thickness direction and the internal fine structure was observed. As a result, the insulating layer containing AlN as a main component was sufficiently densified, no pores were observed, no internal pores were observed in the conductor layer, and defects such as disconnection did not occur.

Further, the insulating layer containing AlN as a main component which constitutes the multilayer ceramic circuit board has a resistivity of 10 ¹¹ Ω.
cm or more, the relative dielectric constant was 8.3, the dielectric loss was 10 ⁻³ or less (both under the condition of 1 MHz), and the thermal conductivity was 138 W · m ⁻¹ · K ⁻¹ . The conductor layer forming the same circuit board had a resistivity as low as 4.8 × 10 ⁻⁶ Ω · cm.

(Embodiment 10) The average primary particle diameter is 0.08μ.
m, AlN powder having an impurity oxygen content of 2.5% by weight, 3.0% by weight of Yb ₂ O ₃ having an average particle size of 0.1 μm, and 1% by weight of SrO having an average particle size of 0.09 μm, respectively. YbCl ₃ 0.7 with an average particle size of 0.1 μm
% By weight and 0.5% by weight of MnO _{2 having an} average particle diameter of 0.1 μm, respectively, and further 0.3% by weight of TiO ₂ in terms of Ti for coloring, and using a ball mill,
Wet mixed in butanol. This mixed powder was dispersed in an organic solvent together with an organic binder, and the obtained slurry was formed into a sheet by a doctor blade method to prepare a plurality of green sheets. By appropriately selecting the type of organic binder, the molding density of this sheet is 6 in terms of relative density.
2% was achieved. Subsequently, a plurality of via holes for interlayer connection were formed at predetermined positions of the obtained green sheet by a punching machine.

On the other hand, a copper powder having an average particle diameter of 1.5 μm and a gold powder having an average particle diameter of 1.0 μm are mixed at a volume ratio of 3: 1 and dispersed in an organic solvent together with an organic binder to prepare a conductor paste. did.

Next, the conductor paste was printed on the green sheet by a screen printing method to form a conductor paste layer on the surface of the sheet, and the via holes were filled with the conductor paste. Subsequently, a plurality of green sheets on which the conductor pate layer was formed were aligned by the via holes, overlapped with each other, and heated and pressed to produce a laminate. Continuing, the laminated body in a nitrogen atmosphere,
After degreasing at 700 ° C, in a nitrogen atmosphere at 1 atm, 1350 ° C
By sintering for 18 hours, the multilayer ceramic circuit board having the structure shown in FIG. 1 was manufactured.

The obtained circuit board was cut in the thickness direction and the internal fine structure was observed. As a result, the insulating layer containing AlN as a main component was sufficiently densified, no pores were observed, no internal pores were observed in the conductor layer, and defects such as disconnection did not occur.

Further, the insulating layer containing AlN as a main component which constitutes the multilayer ceramic circuit board has a resistivity of 10 ¹¹ Ω.
cm or more, the relative dielectric constant was 8.4, the dielectric loss was 10 ⁻³ or less (both under the condition of 1 MHz), and the thermal conductivity was 112 W · m ⁻¹ · K ⁻¹ . The conductor layer forming the circuit board had an extremely low resistivity of 5.4 × 10 ⁻⁶ Ω · cm. (Examples 11 to 16) 6 was performed in the same manner as in Example 9 except that the mixed powder for the insulating layer having the composition shown in Table 3 below and the conductive paste were used and sintered under the conditions shown in Table 3 below. A variety of multilayer ceramic circuit boards were manufactured. The density and thermal conductivity of the insulating layer, the resistivity of the conductive layer, and the appearance of each of the obtained circuit boards were examined. The results are shown in Table 4 below.
Shown in

[0087]

[Table 3]

[0088]

[Table 4]

As is clear from Table 4 above, Examples 11 to 11
It can be seen that each of the 16 multilayer ceramic circuit boards has excellent characteristics and good appearance. (Example 17) Al having an impurity oxygen amount of 2.15% by weight, an average primary particle diameter of 0.07 μm and a specific surface area of 27.6 m ² / g.
N powder 95.0% by weight, average particle size 0.1 μm, purity 9
9.9% YF ₃ 3.5% by weight, average particle size 0.5 μm, purity 99.9% CaF ₂ 1.0% by weight, average particle size 0.
N-Butanol was added to a mixed powder consisting of 0.5% by weight of NaF having a purity of 99.9% at 2 μm, and the mixture was crushed and mixed by a wet ball mill. Using this mixed powder, a green sheet was prepared in the same manner as in Example 9, and a via hole for obtaining an electrical connection between layers was formed. A conductor paste consisting of 70% by volume of Cu powder having an average particle size of 0.8 μm and 30% by volume of a mixed powder containing AlN powder similar to that used for the green sheet as a main component was press-fitted and filled into the via hole. Further, the conductive paste was screen-printed on the green sheet in which the via holes were formed to form a conductive paste layer having a desired pattern to be a conductive layer.

Next, a desired number of the green sheets were laminated and integrated by hot pressing to produce a laminate. Then, the laminate was subjected to external shape processing and heated to a maximum temperature of 700 ° C. in a nitrogen atmosphere to remove the binder. The laminated body after binder removal was put in a graphite container, and after h-BN (hexagonal boron nitride) was interposed between the laminated body and the container, it was heated in a nitrogen atmosphere in a sintering furnace having a carbon heater at 1070 ° C. The package was manufactured by performing hot press sintering under a pressure of 50 MPa for 8 hours.

The obtained package had a good conductor layer (circuit pattern) formed without any blistering or disconnection in appearance and inside. The specific resistance of the conductor layer was 7.3 × 10 ⁻⁶ Ω · cm, which was a sufficiently low resistance.

Comparative Example 3 Y ₂ O ₃ having an impurity oxygen content of 1.10% by weight, an AlN powder having an average primary particle diameter of 0.7 μm 95.7% by weight, an average particle diameter of 0.1 μm and a purity of 99.9%.
3.0% by weight, 0.5% by weight of CaF ₂ with an average particle size of 0.5 μm and a purity of 99.9%, and a purity of 9 with an average particle size of 0.1 μm
Using a mixed powder of 9.9% TiO ₂ in an amount of 0.3% by weight in terms of Ti and 0.5% by weight of P ₂ O _{5 in} a purity of 99.9%, the same method as in Example 9 was performed. A glee sheet was produced. Subsequently, a via hole was formed, a conductor paste was pressed into the via hole, a conductor paste layer was formed by applying a conductor paste, and a binder removal treatment was performed in the same manner as in Example 17. The laminated body after binder removal was set in a sintering container containing AlN as a main component, and was placed in a graphite heater furnace under a nitrogen gas atmosphere of 1 atm for 110
A package was manufactured by performing sintering at 0 ° C. for 8 hours.

In the obtained package, the insulating layer containing AlN as a main component was not completely densified, and it could not be put to practical use as a package. Example 18 AlN having an impurity oxygen content of 3.2% by weight, an average primary particle diameter of 0.06 μm and a specific surface area of 32.3 m ² / g.
Powder 89.0% by weight, average particle size 0.1 μm, purity 99.
6.5% by weight of 9% YF ₃ , 2.0% by weight of CaCO ₃ having an average particle size of 0.5 μm and a purity of 99.9% in terms of CaO,
1.0% by weight of NaF having an average particle size of 0.2 μm and a purity of 99.9%, 1.0% by weight of NaH ₂ PO _{4 having} a purity of 99.9%,
0.5 wt% W with an average particle size of 0.1 μm and a purity of 99.9%
N-Butanol was added to the mixed powder consisting of, and the mixture was crushed and mixed by a wet ball mill. Using this mixed powder, a green sheet was prepared in the same manner as in Example 9, and a via hole for obtaining an electrical connection between layers was formed. 70 μm Au powder with an average particle size of 0.8 μm
% By volume and A similar to that used for the green sheet
A conductor paste consisting of 30% by volume of a mixed powder containing 1N as a main component was pressed and filled. Then, the conductive paste was screen-printed on the green sheet in which the via holes were formed to form a conductive paste layer having a desired pattern to be a conductive layer. Next, the green sheets were laminated in the same manner as in Example 9, subjected to binder removal treatment, and then hot press sintered to manufacture a package.
However, the hot press sintering is performed at 1050 ° C. for 8 hours,
It was carried out under a pressure of 50 MPa.

The obtained package had a good conductor layer (circuit pattern) without blistering or disconnection in the appearance and inside. Further, the conductor layer has a specific resistance of 8.
The resistance was sufficiently low as 5 × 10 ⁻⁶ Ω · cm.

(Example 19) As a conductor paste, 70 wt% of Cu powder having an average particle size of 0.8 μm and a purity of 99.99% and 30 wt% of Cu powder having an average particle size of 0.3 μm and a purity of 99.9% were used. A package was manufactured in the same manner as in Example 17, except that the one used was used.

The obtained package had a good conductor layer (circuit pattern) without blistering or disconnection in appearance and inside. The specific resistance of the conductor layer was 6.1 × 10 ⁻⁶ Ω · cm, which was sufficiently low.

Example 20 Impurity oxygen content 3.72% by weight, average primary particle diameter 0.055 μm, specific surface area 38.5
m ² / g AlN powder 91.0 wt% of an average particle size of 0.1
4.5% by weight of YF _{3 having} a purity of 99.9%, an average particle size of 0.5 μm, and CaCO ₃ having a purity of 99.9% of 1.0% by weight in terms of CaO, an average particle size of 0.3 μm and a purity of 99. .9%
CaF ₂ 1.0% by weight, average particle size 0.2 μm, purity 9
9.9% NaF 1.0% by weight, purity 99.9% Na
A mixed powder composed of 1.0% by weight of H ₂ PO ₄ and 0.5% by weight of W having an average particle size of 0.1 μm and a purity of 99.9%,
n-Butanol was added, and the mixture was crushed and mixed by a wet ball mill. Using this mixed powder, a green sheet was prepared in the same manner as in Example 9, and via holes for obtaining electrical connection between layers were formed. A conductor paste consisting of 70% by volume of Ag powder having an average particle diameter of 0.8 μm and 30% by volume of a mixed powder containing AlN as a main component similar to that used in the green sheet was press-fitted and filled into the via hole. Then, the conductive paste was screen-printed on the green sheet in which the via holes were formed to form a conductive paste layer having a desired pattern to be a conductive layer. Next, the green sheets were laminated in the same manner as in Example 9, subjected to binder removal treatment, and then hot press sintered to manufacture a package. However, the hot press sintering was performed at 950 ° C. for 12 hours under a pressure of 100 MPa.

The obtained package was free from blistering and disconnection in appearance and inside, and both the insulating layer containing AlN as a main component and the conductor layer containing silver as a main component were sufficiently densified, and the conductor layer was good. It had a unique shape. The specific resistance of the conductor layer was 6.3 × 10 ⁻⁶ Ω · cm, which was sufficiently low.

Example 21 By stacking the three green sheets produced in Example 17 and performing hot pressing, a plate-like laminate having a size of 40 × 40 × 0.8 mm was prepared. The maximum temperature was 700 in a nitrogen atmosphere. The binder was removed by heating at ℃.
Subsequently, a conductor paste similar to that used in Example 17 was screen-printed on the upper and lower surfaces of this laminated body layer, further subjected to binder removal treatment, and then hot press sintered in the same manner as in Example 17. The obtained surface metallized circuit board had no external appearance and was not peeled off. The surface of the metallized circuit board had a strong joint even when the interface between the insulating layer containing AlN as a main component and the conductor layer was observed.

[0100]

As described above in detail, according to the present invention, 1
It has an insulating layer containing AlN having a high thermal conductivity of more than 00 W / m · K as a main component, and can sufficiently dissipate a large amount of heat generated by high integration and speedup of semiconductor elements, and as a semiconductor layer. A ceramic circuit board and a circuit board which are free from defects such as disconnection and have a low-resistivity conductor layer that is well adhered to the insulating layer and that can perform high-speed signal transmission when mounting a semiconductor element or the like. A manufacturing method capable of low-temperature co-sintering can be provided.

[Brief description of drawings]

FIG. 1 is a partially cutaway perspective view showing a multilayer ceramic circuit board according to the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Multilayer ceramic circuit board, 2 ... Insulating layer, 3 ... Conductor layer, 4 ... Via hole.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Katsuyoshi Oishi 1 Komukai Toshiba-cho, Sachi-ku, Kawasaki-shi, Kanagawa Toshiba Research & Development Center (72) Inventor Fumio Ueno Komukai, Kawasaki-shi, Kanagawa Toshiba Town No. 1 Inside Toshiba Research and Development Center

Claims (4)

[Claims] 1. An insulating layer having a relative density of 98% or more and containing aluminum nitride as a main component, gold and / or copper as a main component, and 0.01 to 50% by volume of an inorganic compound and / or 0.01 to A ceramic circuit board comprising: a conductor layer containing 15% by weight of at least one active metal selected from titanium, nickel, and aluminum as a filler. 2. An aluminum nitride particle having an average particle size of 5 μm or less, and a rare earth element compound and / or an alkaline earth metal compound as a subphase, respectively, in terms of oxides of 0.
0.05 to 15% by weight, and halogen in the sub-phase,
An insulating layer containing aluminum nitride as a main component, containing at least one component selected from boron and manganese (excluding a mixture of halogen and boron), and a conductor layer containing gold and / or copper as a main component. A ceramic circuit board comprising: 3. The conductive layer contains 0.01 to 50% by volume.
3. The ceramic circuit board according to claim 2, wherein the inorganic compound and / or 0.01 to 15% by weight of at least one active metal selected from titanium, nickel, and aluminum is contained as a filler. 4. A step of producing a compact from a mixed powder containing aluminum nitride powder and a sintering aid, and a conductor paste containing at least one selected from gold, silver and copper on at least the surface of the compact. A step of applying in a pattern to form a conductor paste layer, and the molded body at 1100 ° C. or lower in a non-oxidizing atmosphere.
Hot-press sintering at 0 MPa or more to form a patterned conductor layer containing at least one selected from Au, Ag, and Cu as the main component in the insulating layer containing aluminum nitride as the main component. A method of manufacturing a ceramic circuit board, comprising: