JP4596936B2 - Conductive paste for via conductor, ceramic wiring board using the same, and manufacturing method thereof - Google Patents

Description

  The present invention relates to a conductive paste for via conductors, a ceramic wiring board in which via conductors are formed using the conductive paste for via conductors, and a method for manufacturing the ceramic wiring board.

  In recent years, in an electronic component such as a multilayer ceramic capacitor, particularly in a ceramic wiring board having a multilayer structure of two or more layers, the equivalent series resistance and equivalent series inductance of the conductor wiring provided in the multilayer structure are lowered. For this reason, there is an increasing number of cases where a structure in which the conductor wiring is conductively connected to a via conductor penetrating in the stacking direction of the ceramic wiring board is employed.

  FIG. 5 is a cross-sectional view showing an example of a multilayer ceramic capacitor 90 employing the above structure.

  Referring to FIG. 5, a multilayer ceramic capacitor 90 of this example includes a dielectric block 91 in which a plurality of dielectric layers 92 made of ceramic are stacked.

  Between the dielectric layers 92 forming the dielectric block 91, internal electrodes 93 and 94 as conductor wirings are alternately provided in multiple layers.

  In addition, via conductors 95 and 96 are formed in the dielectric block 91 so as to extend in the stacking direction. On the surface of the dielectric block 91, an external electrode 97 electrically connected to the via conductor 95, and An external electrode 98 conductively connected to the via conductor 96 is formed.

  The internal electrode 93 is provided on the upper surface of the even-numbered dielectric layer 92 counted from the upper surface side of the dielectric block 91 in the drawing, and a region 91 a without an electrode is provided around each via conductor 95. Thus, the via conductor 96 and the external electrode 98 are conductively connected while avoiding contact with the via conductor 95.

  In addition, the internal electrode 94 is provided on the upper surface of the dielectric block 91 (excluding the uppermost layer, that is, the first dielectric layer 92) of the odd-numbered dielectric layer 92 counted from the upper surface side in the drawing. At the same time, a region 91 b without an electrode is provided around the via conductor 96 so as to avoid contact with the via conductor 96 and is electrically connected to the via conductor 95 and the external electrode 97.

  In the region X shown in the drawing, the internal electrode 93 conductively connected to the external electrode 98 via the via conductor 96 and the internal electrode 94 conductively connected to the external electrode 97 via the via conductor 95 are A circuit that functions as a capacitor equivalently is formed across the dielectric layer 92.

  The dielectric layer 92 is formed by firing a green sheet containing a ceramic component and an organic binder resin.

  The internal electrodes 93 and 94 are formed by applying a conductive paste for conductive wiring containing Ni as a conductive component and an organic binder resin to the surface of a green sheet so as to have a predetermined planar shape by screen printing or the like. It is formed by firing together with a green sheet.

  The via conductors 95 and 96 are formed by firing together with a green sheet in a state where a conductive paste for via conductor is filled in a through hole formed in the green sheet.

  As the conductive paste for via conductors, a paste containing Cu powder, Ni powder, a ceramic component and an organic binder resin is preferably used.

  In the conductive paste for via conductors, Cu powder forms a solid solution with Ni powder at the time of firing, thereby suppressing the shrinkage of the via conductors 95 and 96 due to firing, so that the conductive connection with the internal electrodes 93 and 94 is good. To function.

  In addition, the ceramic component functions to suppress the progress of the sintering of the conductive paste for via conductors faster than the firing of the green sheet during firing.

  Therefore, it is possible to prevent the multilayer ceramic capacitor 90 from being cracked.

  When firing to form a ceramic wiring board such as the above-mentioned multilayer ceramic capacitor 90, the organic binder resin contained in the green sheet or conductive paste, which causes internal defects such as delamination, is fully burned and decomposed. In order to achieve this, oxygen of a predetermined concentration is introduced in the middle of firing.

  However, Cu powder and Ni present in the paste in close proximity to each other during baking with oxygen introduced or while the conductive paste for via conductors is stored in the atmosphere for a long period of time. In some cases, the powder reacts to produce a Cu—Ni alloy. When the Cu—Ni alloy is produced, there is a problem in that the electrical resistance of the via conductor increases and the conductivity decreases.

  An object of the present invention is to prevent a Cu powder and a Ni powder from reacting to form a Cu-Ni alloy, and to form a via conductor having a better conductivity than in the past. An object is to provide a conductive paste for via conductors.

  Another object of the present invention is to provide a ceramic wiring board having via conductors formed using the above conductive paste for via conductors and a method for manufacturing the same.

  The conductive paste for via conductor according to the present invention is filled in a through-hole formed in a green sheet containing a ceramic component, and is baked together with the green sheet to form a via conductor, and has a glass layer on the surface. It contains powder, Ni powder having a metal oxide layer on its surface, and a ceramic component of the same quality as the ceramic component contained in the green sheet.

  Further, the volume ratio Va of the Cu powder, the volume ratio Vb of the Ni powder, and the volume ratio Vc of the ceramic component satisfy all of the expressions (1) to (5).

0.01 ≦ Va ≦ 0.1 (1)
0.9 ≦ Vb ≦ 0.99 (2)
0.01 ≦ Vc ≦ 0.3 (3)
Va + Vb = 1 (4)
1.01 ≦ Va + Vb + Vc ≦ 1.3 (5)
Further, the average thickness of the glass layer on the surface of the Cu powder is 5.0 to 50 nm, and the average thickness of the metal oxide layer on the surface of the Ni powder is 1.0 to 20 nm.

  Furthermore, the average particle size of the Cu powder is 0.1 to 1.0 μm, the average particle size of the Ni powder is 0.1 to 10 μm, and the average particle size of the ceramic component is 0.1 to 1.0 μm. And

  Furthermore, as the Ni powder, two types of Ni powders having different average particle diameters are used in combination.

  The ceramic wiring board of the present invention has a via conductor formed by firing the conductive paste for via conductor according to claim 1.

  The method for manufacturing a ceramic wiring board according to the present invention includes a step of forming a through hole in a green sheet, a step of filling the formed through hole with the conductive paste for via conductors according to claim 1, and forming a conductor wiring by firing. Applying a conductive paste for conductive wiring containing Ni as a conductive component to the surface of the green sheet so that part of the conductive paste is in contact with the conductive paste for via conductor filled in the through hole; And a step of simultaneously firing the conductive paste for via conductor and the conductive paste for conductor wiring.

  In addition, the method includes a step of filling a plurality of green sheets, each filled with a conductive paste for via conductors in a through hole, and coated with a conductive paste for conductor wiring on the surface, before firing. It is characterized by being integrated by firing.

  Further, the method for producing a ceramic wiring board of the present invention comprises forming conductive wiring by firing, conductive paste for conductive wiring containing Ni as a conductive component on the surface of the green sheet, part of which is green sheet, The step of applying so as to overlap the region where the through hole is formed, the step of forming the through hole in the green sheet, the step of removing the conductive paste for the conductor wiring that overlaps the through hole, The step of filling the conductive paste for via conductors of claim 1 so as to be in contact with a part of the conductive paste for conductor wiring applied to the surface, the green sheet, the conductive paste for via conductors, and the conductive property for conductor wiring And a step of simultaneously baking the paste.

  In addition, including a step of stacking a plurality of green sheets coated with conductive paste for conductor wiring on the surface before forming the through holes, forming the through holes by penetrating the plurality of stacked green sheets, After filling the conductive paste for via conductors, a plurality of stacked green sheets are integrated by firing.

  According to the conductive paste for via conductors of the present invention, the surface of Cu powder is coated with a glass layer, and the surface of Ni powder is coated with a metal oxide layer, so that Cu powder and Ni powder react. Thus, the formation of the Cu—Ni alloy can be effectively prevented.

  Therefore, it is possible to form a via conductor having good conductivity.

  In the conductive paste for via conductors of the present invention, the volume ratio Va of the Cu powder, the volume ratio Vb of the Ni powder, and the volume ratio Vc of the ceramic component satisfy all the expressions (1) to (5). It is preferable.

0.01 ≦ Va ≦ 0.1 (1)
0.9 ≦ Vb ≦ 0.99 (2)
0.01 ≦ Vc ≦ 0.3 (3)
Va + Vb = 1 (4)
1.01 ≦ Va + Vb + Vc ≦ 1.3 (5)
When the volume ratios Va to Vc are within the above range, the functions of the Cu powder and the ceramic component described above are effectively exhibited to produce a ceramic wiring board having good characteristics. Can do.

  That is, by the function of the Cu powder, the shrinkage of the via conductor can be suppressed at the time of firing, and the conductive connection with the conductor wiring such as the internal electrode can be made even better.

  In addition, due to the function of the ceramic component, during firing, the sintering of the conductive paste for via conductors is suppressed from proceeding faster than the firing of the green sheet, and the cracks in the ceramic wiring board are further generated. It can also be surely prevented.

  In the conductive paste for via conductors of the present invention, the average thickness of the glass layer on the surface of Cu powder is 5.0 to 50 nm, and the average thickness of the metal oxide layer on the surface of Ni powder is 1.0 to 20 nm. Preferably there is.

  If the average thicknesses of the glass layer and the metal oxide layer are within the above ranges, respectively, the formation of a Cu—Ni alloy due to the reaction between the Cu powder and the Ni powder can be more reliably prevented, and the via conductor can be formed. Further, it is possible to impart good conductivity.

  In the conductive paste for via conductors of the present invention, the average particle size of Cu powder is 0.1 to 1.0 μm, the average particle size of Ni powder is 0.1 to 10 μm, and the average particle size of ceramic components is 0.1. It is preferable that it is -1.0 micrometer.

  If the average particle size of Cu powder, Ni powder and ceramic component is within the above range, Cu powder, Ni powder and ceramic component in the conductive paste for via conductor, respectively, without causing aggregation, It can be uniformly dispersed.

  Therefore, during firing, Cu powder and Ni powder react to effectively prevent the formation of a Cu-Ni alloy, and Cu powder and Ni powder are unevenly distributed in the via conductor. Therefore, it is possible to impart even better and uniform conductivity to the via conductor.

  In addition, during firing, the sintering of the conductive paste for via conductors can be prevented from proceeding faster than the firing of the green sheet, and it is possible to more reliably prevent cracks in the ceramic wiring board. it can.

  As the Ni powder, it is preferable to use two kinds of Ni powders having an average particle diameter within the above range and different from each other. When two kinds of Ni powders having different average particle diameters are used in combination, the packing density of the Ni powder can be increased, and a better and even conductivity can be imparted to the via conductor. Further, the shrinkage of the via conductor can be suppressed during firing, and the conductive wiring such as the internal electrode can be more conductively connected.

  The ceramic wiring board of the present invention has a via conductor formed by firing the conductive paste for via conductor of the present invention.

  Therefore, according to the ceramic wiring board of the present invention, the electrical conductivity of the via conductor can be improved and the conductive wiring can be satisfactorily connected to the conductor wiring.

  Therefore, particularly in a ceramic wiring board having a laminated structure of two or more layers, it is possible to reduce the equivalent series resistance and equivalent series inductance of the conductor wiring provided in the laminated structure.

  In addition, it is possible to prevent the ceramic wiring board from cracking by suppressing the progress of the sintering of the conductive paste for via conductors faster than the firing of the green sheet during firing.

  The method for producing a ceramic wiring board of the present invention includes a step of forming a through hole in a green sheet, a step of filling the formed through hole with the conductive paste for via conductor of claim 1, and forming a conductor wiring by firing. Applying a conductive paste for conductive wiring containing Ni as a conductive component to the surface of the green sheet so that a part of the conductive paste is in contact with the conductive paste for via conductor filled in the through hole; And a step of simultaneously firing the conductive paste for conductor and the conductive paste for conductor wiring.

  According to the manufacturing method of the present invention, through each of the above steps, the ceramic wiring is excellent in conductivity as described above, has a via conductor well connected to the conductor wiring, and has no cracks. A board can be manufactured efficiently.

  In addition, in order to manufacture a ceramic wiring board having a laminated structure of two or more layers by the manufacturing method of the present invention, a conductive paste for via conductor is filled in the through hole, and the conductive paste for conductor wiring is formed on the surface. It is preferable to include a step of stacking a plurality of applied green sheets before firing, and integrating the plurality of stacked green sheets by firing.

  The method for producing a ceramic wiring board according to the present invention comprises forming a conductive wiring by firing, a conductive paste for conductive wiring containing Ni as a conductive component on the surface of a green sheet, a part of which is a through hole of the green sheet. The step of applying so as to overlap the region for forming the conductive layer, the step of forming the through hole in the green sheet, the step of removing the conductive paste for conductor wiring overlapping the through hole, and the formed through hole on the surface of the green sheet The step of filling the conductive paste for via conductor of claim 1 so as to be in contact with a part of the applied conductive paste for conductive wiring, the green sheet, the conductive paste for via conductor, and the conductive paste for conductive wiring are simultaneously performed. And a step of firing.

  According to the manufacturing method of the present invention, through each of the above steps, the ceramic wiring is excellent in conductivity as described above, has a via conductor well connected to the conductor wiring, and has no cracks. A board can be manufactured efficiently.

  Moreover, in order to manufacture a ceramic wiring board having a laminated structure of two or more layers by the manufacturing method of the present invention, a plurality of green sheets coated with conductive paste for conductor wiring are formed on the surface, and through holes are formed. Including a step of overlapping before forming, through the plurality of stacked green sheets to form through holes, filling with conductive paste for via conductors, and then integrating the stacked plurality of green sheets by firing It is preferable to do so.

  Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

  The conductive paste for via conductors of the present invention contains Cu powder having a glass layer on the surface, Ni powder having a metal oxide layer on the surface, and a ceramic component of the same quality as the ceramic component contained in the green sheet. It is characterized by.

Examples of the glass layer provided on the surface of the Cu powder include quartz glass (SiO ₂ ), soda lime glass (Na ₂ O—CaO—SiO ₂ ), potash lime glass (K ₂ O—CaO—SiO ₂ ), and alkali. Of silicate glass such as glass (K ₂ O—PbO—SiO ₂ ), barium glass (BaO—SiO ₂ —B ₂ O ₃ ), borosilicate glass (Na ₂ O—B ₂ O ₃ —SiO ₂ ), etc. The layer which consists of 1 type (s) or 2 or more types is mentioned.

  The average thickness of the glass layer is preferably 5.0 to 50 nm.

  When the average thickness of the glass layer is less than 5.0 nm, there is a possibility that the effect of preventing the Cu powder and the Ni powder from reacting and generating a Cu—Ni alloy by the glass layer may not be sufficiently obtained. .

  In addition, when the average thickness of the glass layer exceeds 50 nm, there is a possibility that the effect of good conductive connection between the via conductor and the conductor wiring may not be sufficiently obtained by forming a solid solution with the Ni powder by the Cu powder. is there.

  The average thickness of the glass layer is such that Cu powder having a glass layer on the surface is mixed with a thermosetting resin to prepare a paste, and this paste is heated to 150 to 200 ° C. to thermoset the thermosetting resin. After forming a solid sample body, it was polished, and the polished surface was finally finished to a mirror surface with a diamond paste, and was observed with a scanning electron microscope at a magnification of 8000 times or more. The operation for measuring the thickness is expressed by an average value obtained for a plurality of Cu powders exposed on the polished surface.

  In addition, although actual Cu powder is based also on the formation method etc., the whole surface may not necessarily be coat | covered with the glass layer.

  Even in that case, when the average thickness of the glass layer obtained by the above method is within the preferred range presented above, the Cu powder is prevented from reacting with the Ni powder to form a Cu-Ni alloy. Is possible.

  Therefore, the entire surface of the Cu powder may be covered with the glass layer or may be partially exposed.

  The average particle diameter of the Cu powder is preferably 0.1 to 1.0 μm.

  When the average particle diameter of the Cu powder is less than 0.1 μm or exceeds 1.0 μm, the Cu powder tends to aggregate in the conductive paste for via conductors in either case.

  Therefore, the Ni powder and the ceramic component are also easily aggregated, and it may not be possible to effectively prevent the Cu powder and the Ni powder from reacting and generating a Cu—Ni alloy during firing.

  In addition, Cu powder and Ni powder are unevenly distributed in the via conductor, and the conductivity of the via conductor may be reduced or non-uniform.

  In addition, Cu powder can be effectively solid-solved with respect to Ni powder by baking, so that the particle size is small.

  Therefore, it is possible to suppress the shrinkage of the conductive paste for via conductors at the time of firing, and to connect the via conductors to the conductor wirings with good conductivity.

  Therefore, the smaller the average particle diameter of the Cu powder is, the more preferable it is within the above range.

  The average particle diameter of the Cu powder is the average value of the particle diameter of the Cu powder itself in a state where no glass layer is formed on the surface, and the Cu powder is observed at a magnification of 8000 times or more using a scanning electron microscope. Then, the operation for measuring the particle diameter is expressed by an average value obtained for a plurality of Cu powders.

Cu powder having a glass layer on the surface can be produced, for example, by spray pyrolysis. For example, Cu powder having a SiO ₂ layer as a glass layer is sprayed with Cu powder and a compound containing Si in a reducing atmosphere, and the compound is attached to the surface of the Cu powder, and then the The compound is produced by thermally decomposing in an oxidizing atmosphere such as the air to generate SiO ₂ .

  As the metal oxide layer provided on the surface of the Ni powder, for example, a layer made of a single oxide of Ni, Al, Y, Zr, Ti, Mg, Ca, Sr, or Ba, or 2 of the above oxides. Metals that are more stable than Ni powder at high temperatures, such as layers composed of a mixture of two or more species, layers composed of complex oxides containing two or more of the above metals, and layers composed of complex oxides of the above metals and other metals Examples thereof include a layer made of an oxide.

  The average thickness of the metal oxide layer is preferably 1.0 to 20 nm. When the average thickness of the metal oxide layer is less than 1.0 nm, Cu powder and Ni powder react with the metal oxide layer. Thus, the effect of preventing the formation of the Cu—Ni alloy may not be sufficiently obtained.

  In addition, when the average thickness of the metal oxide layer exceeds 20 nm, the effect of conducting the conductive connection between the via conductor and the conductor wiring cannot be sufficiently obtained by forming a solid solution with Ni powder using Cu powder. There is a fear.

  The average thickness of the metal oxide layer can be determined in the same manner as the average thickness of the glass layer.

  That is, a Ni powder having a metal oxide layer on the surface is mixed with a thermosetting resin to prepare a paste, and the paste is heated to 150 to 200 ° C. to thermoset the thermosetting resin to form a solid. After forming the sample body, the metal oxide layer is polished by observing at a magnification of 8000 times or more with a scanning electron microscope in a state where the polished surface is finally finished to a mirror surface with diamond paste. The operation for measuring is represented by an average value obtained for a plurality of Ni powders exposed on the polished surface.

  In addition, although actual Ni powder is based on the formation method etc., the whole surface may not necessarily be coat | covered with the metal oxide layer.

  Even in that case, when the average thickness of the metal oxide layer determined by the above method is within the preferred range presented above, the Cu powder reacts with the Ni powder to form a Cu-Ni alloy. Can be prevented.

  Therefore, the Ni powder may be entirely covered with the metal oxide layer or partially exposed.

  The average particle diameter of the Ni powder is preferably 0.1 to 10 μm.

  When the average particle diameter of the Ni powder is less than 0.1 μm or exceeds 10 μm, the Ni powder easily aggregates in the conductive paste for via conductors in either case.

  Therefore, the Cu powder and the ceramic component are also easily aggregated, and it may not be possible to effectively prevent the Cu powder and the Ni powder from reacting and generating a Cu—Ni alloy during firing.

  In addition, Cu powder and Ni powder are unevenly distributed in the via conductor, and the conductivity of the via conductor may be reduced or non-uniform.

  As the Ni powder, it is preferable to use two kinds of Ni powders having an average particle diameter within the above range and different from each other. When two kinds of Ni powders having different average particle diameters are used in combination, the packing density of the Ni powder can be increased, and a better and even conductivity can be imparted to the via conductor. Further, the shrinkage of the via conductor can be suppressed during firing, and the conductive wiring such as the internal electrode can be more conductively connected. The ratio of the particle diameters of the two Ni powders to be combined is preferably such that the average particle diameter of the small Ni powder is 5 to 35% of the average particle diameter of the large Ni powder. Even if the average particle size of the Ni powder having a small particle size is smaller or larger than this range, the effect of increasing the packing density of the Ni powder may not be sufficiently obtained. Moreover, it is preferable to mix | blend 10-35 weight part of Ni powder of a small particle size with respect to 100 weight part of Ni powder of a large particle size as 2 types of Ni powder. Even if the blending amount of the Ni powder having a small particle size is smaller or larger than this range, the effect of increasing the packing density of the Ni powder may not be sufficiently obtained.

  The average particle diameter of the Ni powder is the average value of the particle diameter of the Ni powder itself in a state where no metal oxide layer is formed on the surface, and the Ni powder is magnified by 8000 times or more using a scanning electron microscope. The operation for observing and measuring the particle size is expressed by an average value obtained for a plurality of Ni powders.

  Ni powder having a metal oxide layer on the surface can be produced, for example, by spray pyrolysis. That is, Ni powder having a metal oxide layer on its surface is sprayed with Ni powder and a compound containing a metal that is the basis of the metal oxide in a reducing atmosphere, and the above compound is applied to the surface of Ni powder. Then, the compound is thermally decomposed in an oxidizing atmosphere such as the air and then oxidized to produce a metal oxide.

  When the metal oxide layer is a Ni oxide layer, a metal oxide layer having a predetermined thickness can be formed simply by adjusting the oxygen concentration after spraying. By adjusting the conditions, a metal oxide layer having a predetermined thickness can be formed.

  As the ceramic component, the ceramic component of the same quality as the ceramic component contained in the green sheet, that is, the main component is the same or similar, and the sintering behavior and temperature characteristics at the time of firing are approximated. Various ceramic components having a function of suppressing the progress of the sintering of the conductive paste for conductors from proceeding faster than the firing of the green sheet can be used.

For example, when the green sheet contains barium titanate (BaTiO ₃ ) as the main component of the ceramic component, it is preferable to use the same BaTiO ₃ as the ceramic component of the conductive paste for via conductors.

  The average particle size of the ceramic component is preferably 0.1 to 1.0 μm.

  When the average particle size of the ceramic component is less than 0.1 μm or exceeds 1.0 μm, in either case, the ceramic component tends to aggregate in the conductive paste for via conductors.

  For this reason, Cu powder and Ni powder are also easily aggregated, and it may not be possible to effectively prevent the Cu powder and Ni powder from reacting and generating a Cu—Ni alloy during firing.

  In addition, Cu powder and Ni powder are unevenly distributed in the via conductor, and the conductivity of the via conductor may be reduced or non-uniform.

  The average particle size of the ceramic component is expressed by an average value obtained by performing an operation for measuring the particle size by observing the ceramic component at a magnification of 8000 times or more using a scanning electron microscope. To do.

  In the conductive paste for via conductors of the present invention, the volume ratio Va of the Cu powder, the volume ratio Vb of the Ni powder, and the volume ratio Vc of the ceramic component satisfy all the expressions (1) to (5). It is preferable.

0.01 ≦ Va ≦ 0.1 (1)
0.9 ≦ Vb ≦ 0.99 (2)
0.01 ≦ Vc ≦ 0.3 (3)
Va + Vb = 1 (4)
1.01 ≦ Va + Vb + Vc ≦ 1.3 (5)
When the volume ratio Va of the Cu powder is less than 0.01, by forming a solid solution with the Ni powder by the Cu powder, the shrinkage of the via conductor due to the firing is suppressed, and the conductive wiring and the conductive connection are sufficiently effective. It may not be obtained.

  Further, when the volume ratio Va exceeds 0.1, Cu has a melting point lower than that of Ni, easily evaporates at the time of firing, and since the progress of sintering is fast, voids in the via conductor increase, There is a possibility that the conductivity of the via conductor may be reduced, or the via conductor may be greatly contracted, and the conductive wiring may not be satisfactorily connected to the conductor wiring.

  When the volume ratio Vb of the Ni powder is less than 0.9, the volume ratio Va of the Cu powder is relatively large, so that the gap in the via conductor is increased as described above, and the conductivity of the via conductor is increased. Otherwise, the via conductor may contract greatly, and it may not be able to conduct a good conductive connection with the conductor wiring.

  In addition, when the volume ratio Vb exceeds 0.99, the volume ratio Va of the Cu powder becomes relatively small, so that the via conductor shrinks due to firing by forming a solid solution with the Ni powder by the Cu powder. There is a possibility that the effect of conducting conductive connection with the conductor wiring is not sufficiently obtained.

  When the volume ratio Vc of the ceramic component is less than 0.01, the ceramic wiring board is suppressed by suppressing the sintering of the conductive paste for the via conductor during the firing by the ceramic component faster than the firing of the green sheet. There is a risk that the effect of preventing cracks from being sufficiently generated is not obtained.

  In addition, when the volume ratio Vc of the ceramic component exceeds 0.3, the volume ratios Va and Vb of the Cu powder and the Ni powder are relatively small, so that the conductivity of the via conductor may be reduced.

  The conductive paste for via conductors may contain an organic binder resin, a solvent, etc. in addition to the Cu powder, Ni powder and ceramic component.

  As an organic binder resin, Cu powder, Ni powder and ceramic components can be uniformly dispersed, and a conductive paste for via conductor is filled into a through-hole formed in a green sheet (for example, screen printing). Various resins can be used that can provide suitable viscosity and rheology.

  Examples of the organic binder resin include acrylic resin, phenol resin, alkyd resin, rosin ester, ethyl cellulose, methyl cellulose, polyvinyl alcohol, and polyvinyl butyral.

  As the solvent, various solvents can be used that dissolve the organic binder resin and disperse the Cu powder, the Ni powder, and the ceramic component to make the entire mixed system into a paste.

  Examples of the solvent include alcohol solvents (for example, α-terpineol, benzyl alcohol, etc.), hydrocarbon solvents, ether solvents, ester solvents (for example, diethylene glycol monobutyl ether acetate), naphtha, and the like.

  In particular, from the viewpoint of improving the dispersibility of Cu powder and Ni powder, the solvent is preferably an alcohol solvent such as α-terpineol.

  The content of the organic binder resin and the solvent can be set in an appropriate range that can give the conductive paste for via conductors a viscosity and rheology suitable for the filling method of the through holes formed in the green sheet. it can.

  The conductive paste for via conductors may further contain a dispersant, an activator, a plasticizer, and the like as necessary.

  The ceramic wiring board of the present invention has a via conductor formed by firing the conductive paste for a via conductor of the present invention.

  FIG. 1 is a cross-sectional view showing a multilayer ceramic capacitor 10 as an example of an embodiment of the ceramic wiring board of the present invention.

  Referring to FIG. 1, a multilayer ceramic capacitor 10 of this example includes a dielectric block 1 in which a plurality of dielectric layers 2 made of ceramic are stacked.

  Between the dielectric layers 2 forming the dielectric block 1, internal electrodes 3 and 4 as conductor wirings are alternately provided in multiple layers.

  In addition, via conductors 5 and 6 are formed in the dielectric block 1 so as to penetrate the lamination direction. On the surface of the dielectric block 1, external electrodes 7 electrically connected to the via conductors 5 are provided. An external electrode 8 that is conductively connected to the via conductor 6 is formed.

  The internal electrode 3 is provided on the upper surface of the even-numbered dielectric layer 2 counted from the upper surface side in the figure of the dielectric block 1, and a region 13 without an electrode is provided around each via conductor 5. Thus, the via conductor 6 and the external electrode 8 are conductively connected while avoiding contact with the via conductor 5.

  The internal electrode 4 is provided on the upper surface of the dielectric block 1, which is an odd-numbered dielectric layer 2 (excluding the uppermost layer, ie, the first dielectric layer 2) counted from the upper surface side in the drawing. At the same time, a region 14 without an electrode is provided around the via conductor 6 so as to avoid contact with the via conductor 6 and is electrically connected to the via conductor 5 and the external electrode 7.

  In the region X shown in the figure, the internal electrode 3 conductively connected to the external electrode 8 via the via conductor 6 and the internal electrode 4 conductively connected to the external electrode 7 via the via conductor 5 A circuit that functions equivalently as a capacitor is formed across the dielectric layer 2.

The dielectric layer 2 is formed by firing a green sheet containing a ceramic component such as BaTiO ₃ and an organic binder resin.

As described above, as the green sheet, those containing a ceramic component such as BaTiO ₃ and an organic binder resin are preferably used.

  Specifically, a ceramic slurry is prepared by mixing the ceramic component with a sintering aid, an organic binder resin, a plasticizer, a dispersant, a solvent, and the like, and the ceramic slurry is molded into a sheet and dried. A green sheet is formed.

  Examples of the method for forming the ceramic slurry into a sheet include a doctor blade method, a pulling method, a coating method using a die coater, and a coating method using a gravure roll coater.

The ceramic component, the BaTiO ₃ as a main component, as a subcomponent, a dielectric material such as magnesium titanate (MgTiO ₃₎ or titanium manganese (MnTiO ₃₎ was added, and further, if necessary, yttrium oxide (Y _{And a} mixture of rare earth metal compounds such as ₂ O ₃ ).

  The sintering aid has a function of lowering the shrinkage start temperature of the green sheet by firing.

  Examples of the sintering aid include a liquid phase forming substance that becomes a glass component, a metal oxide, and the like.

  Examples of the organic binder resin include polyvinyl butyral resin, ethyl cellulose resin, and acrylic resin.

  Examples of the plasticizer include polyethylene glycol and phthalate ester.

  Examples of the solvent include water as a water-soluble solvent, and organic solvents such as toluene, ethyl acetate, terpineol, and a mixture thereof.

  Examples of the dispersant include a carboxylic acid type polymer surfactant as a dispersant that is preferably used with a water-soluble solvent, and examples of a dispersant that is preferably used with an organic solvent include polyoxyethylene ether and amphoteric ion Surfactants.

  The internal electrodes 3 and 4 are obtained by applying a conductive paste for conductive wiring containing Ni as a conductive component and an organic binder resin to the surface of a green sheet so as to have a predetermined planar shape by screen printing or the like. It is formed by firing together with a green sheet.

  As the conductive paste for conductor wiring, a paste containing Ni powder and an organic binder resin is preferably used.

  Specifically, a conductive paste for conductor wiring is prepared by adding a solvent capable of dissolving the organic binder resin to Ni powder and the organic binder resin to dissolve the organic binder resin.

  In consideration of preventing aggregation in the conductive paste for conductor wiring, it is preferable to use Ni powder having an average particle diameter of 0.1 to 10 μm.

  Examples of the organic binder resin and the solvent thereof include the same organic binder resins and solvents as those described above for the conductive paste for via conductors.

  The content of the organic binder resin and the solvent should be set in an appropriate range that can give the conductive paste for conductor wiring a viscosity and rheology suitable for the method of applying to the surface of the green sheet (screen printing, etc.). Can do.

  The conductive paste for conductor wiring may further contain a dispersant, an activator, a plasticizer, and the like as necessary.

  The via conductors 5 and 6 are formed by firing together with the green sheet in a state where the conductive paste for via conductor of the present invention is filled in the through-hole formed in the green sheet.

  For example, after forming the dielectric block 1 by integrally baking the green sheets, the external electrodes 7 and 8 are made of the same conductive paste for conductor wiring as the internal electrodes 3 and 4 on the surface of the dielectric block 1. The film is applied by screen printing or the like so as to have a predetermined planar shape.

  FIG. 2A to FIG. 2E are cross-sectional views showing respective steps for manufacturing the multilayer ceramic capacitor 10 by the manufacturing method of the present invention.

  Referring to these drawings, in this manufacturing method, first, a green sheet 20 that is the basis of each dielectric layer 2 is prepared.

  One green sheet 20 may be formed in a size corresponding to one dielectric layer 2. However, one green sheet 20 is formed to have a size including a plurality of regions corresponding to one dielectric layer 2, and through holes 15 and 16 described below are formed for each region. After conducting the steps of filling the conductive pastes 50 and 60 for via conductors and applying the conductive pastes 30 and 40 for conductive wiring, the laminate 11 is formed by superposing a plurality of green sheets 20. It is preferable in terms of manufacturing efficiency to cut out individual regions from the stacked body 11 and to manufacture a plurality of stacked bodies that are the basis of the dielectric block 1.

  Next, through holes 15 and 16 filled with conductive paste for via conductors are formed at predetermined positions of each green sheet 20 by, for example, drilling or punching using a micro drill. (FIG. 2A).

  The through holes 15 and 16 are formed at the same position so as to overlap each other in the surface direction when a plurality of green sheets 20 are stacked.

  In addition, when forming the diameter of the through-holes 15 and 16 comparatively small, it is preferable to irradiate the surface of the green sheet 20 with a UV-YAG laser, for example.

  In addition, the green sheet 20 in which the through holes 15 and 16 have been formed is preferably immersed in water and ultrasonically cleaned to remove the remaining processing waste.

  Next, the conductive pastes 50 and 60 for via conductors are filled in the formed through holes 15 and 16 by screen printing or the like (FIG. 2B).

  Next, the surface of the green sheet 20 that is the basis of the even-numbered dielectric layer 2 counted from the upper surface side of the dielectric block 1 is used for conductor wiring that is the basis of the internal electrode 3 by screen printing or the like. The conductive paste 30 is applied so as to have a predetermined planar shape (FIG. 2C).

  Specifically, in the state where the conductive paste 30 for conductor wiring is not provided around the through-hole 15, the region 13 is not applied and the contact with the via-conductor conductive paste 50 filled in the through-hole 15 is avoided. The via-conductor conductive paste 60 filled in the through-hole 16 is applied so as to overlap with the via-conductor conductive paste 60.

  Further, screen printing is performed on the surface of the green sheet 20 which is the basis of the odd-numbered dielectric layer 2 (excluding the uppermost layer, that is, the first dielectric layer 2) counted from the upper surface side of the dielectric block 1. The conductive wiring conductive paste 40 that becomes the base of the internal electrode 4 is applied so as to have a predetermined planar shape (FIG. 2D).

  Specifically, in a state where the conductive paste 40 for conductor wiring is not provided around the through-hole 16 and the region 14 is not applied, the contact with the via-conductor conductive paste 60 filled in the through-hole 16 is avoided. The via conductor 15 is applied so as to be in contact with the via conductor conductive paste 50 filled in the through hole 15.

  The two types of green sheets 20 are alternately stacked in the thickness direction while aligning the through holes 15 and 16, and the uppermost layer (first dielectric layer 2) and After the green sheets 20 to be stacked are stacked while the through holes 15 and 16 are aligned, the stacked body 11 is formed by pressing from above and below (FIG. 2 (e)).

  As shown in FIG. 2B, the uppermost green sheet 20 is filled with via-conductor conductive pastes 50 and 60 in the through-holes 15 and 16, and then the conductive pastes 30 and 40 for conductor wiring on the surface. It is formed without applying.

  The via conductor conductive paste of the present invention having exactly the same composition is used as the via conductor conductive pastes 50 and 60 and the conductor wiring conductive pastes 30 and 40 to fill the through holes 15 and 16. And application to the surface of the green sheet 20 may be performed in one step.

  In this case, it is possible to simplify the manufacturing process by omitting the alignment and printing processes.

  In addition, the two green sheets 20 that are alternately stacked have the same formation positions of the through holes 15 and 16 and the application shape of the conductive pastes 30 and 40 for the conductor wiring, and only the stacking direction is different. One type of green sheet 20 that can be used as two types of green sheets 20 may be substituted.

  In this case, the types of green sheets 20 can be reduced to simplify the manufacturing process.

  Next, as described above, in the case where one green sheet 20 is formed to have a size including a plurality of regions corresponding to one dielectric layer 2, the stacked body 11 For each area, for example, it is cut out by using a push cut. When the thickness of the laminated body 11 is large, it may be cut out by dicing.

  Thereafter, the laminated body cut out is placed in, for example, a heating furnace and heated to 250 to 400 ° C. to remove the organic binder resin and other organic substances, and then placed in a main firing furnace to 1250 to 1300 ° C. After the dielectric block 1 shown in FIG. 1 is formed by heating and firing, external electrodes 7 and 8 are formed on the surface of the dielectric block 1 to produce the multilayer ceramic capacitor 10 shown in FIG.

  FIG. 3A to FIG. 3E are cross-sectional views showing respective steps for manufacturing the multilayer ceramic capacitor 10 by another manufacturing method of the present invention.

  In this manufacturing method, first, on the surface of the green sheet 20 that is the basis of the even-numbered dielectric layer 2 counted from the upper surface side of the dielectric block 1, it becomes the source of the internal electrode 3 by screen printing or the like. The conductive paste 30 for conductor wiring is applied so as to have a predetermined planar shape (FIG. 3A).

  Specifically, the conductive paste for conductive wiring 30 is not provided around the position where the through hole 15 is formed in a later step, and the conductive paste for via conductor filled in the through hole 15 is provided. In addition to avoiding contact with the through hole 16, it is applied over the position where the through hole 16 is formed so as to come into contact with the conductive paste 60 for via conductor filled in the through hole 16.

  Further, screen printing or the like is performed on the surface of the green sheet 20 that is the basis of the odd-numbered dielectric layer 2 (excluding the uppermost layer, that is, the first dielectric layer 2) counted from the upper surface side of the dielectric block 1. Thus, the conductive paste 40 for conductor wiring that becomes the base of the internal electrode 4 is applied so as to have a predetermined planar shape (FIG. 3B).

  Specifically, the conductive paste 40 for conductor wiring is provided in a region 14 where the conductive paste 40 for conductor wiring is not applied around the position where the through hole 16 is formed in a later step, and is filled in the through hole 16. In addition to avoiding contact with the through hole 15, it is applied over the position where the through hole 15 is formed so as to be in contact with the via conductor conductive paste 50 filled in the through hole 15.

  As in the case of the previous manufacturing method, the green sheet 20 is formed to have a size including a plurality of regions corresponding to the single dielectric layer 2, and a conductive paste for conductor wiring is formed for each region. The laminated body 11 is formed by performing steps 30 and 40, lamination, formation of the through holes 15 and 16, and filling of the conductive pastes 50 and 60 for via conductors, and individual regions are formed from the formed laminated body 11. It is preferable in terms of manufacturing efficiency to cut out and manufacture a plurality of laminated bodies that are the basis of the dielectric block 1.

  Next, while aligning the two types of green sheets, a plurality of sheets are alternately stacked in the thickness direction, and conductive pastes 30 and 40 for conductor wiring, which are uppermost layers, are applied thereon. After stacking the green sheets 20 that are not aligned, pressure is applied from above and below to form the laminate 11 (FIG. 3C).

  Note that the two green sheets 20 that are alternately stacked have the same formation positions of the through holes 15 and 16 and the application shape of the conductive pastes 30 and 40 for the conductor wiring, and only the stacking direction is different. One type of green sheet 20 that can be used as two types of green sheets 20 may be substituted.

  In this case, the types of green sheets 20 can be reduced to simplify the manufacturing process.

  Next, the surface of the formed laminate 11 is irradiated with, for example, a UV-YAG laser having a wavelength of 350 nm to form the through holes 15 and 16, and the conductive property for conductor wiring that overlaps the through holes 15 and 16. The paste is removed (FIG. 3 (d)).

  The through hole 15 penetrates through the center of the region 13 of the dielectric block 1 where the conductive paste 30 for conductor wiring is not applied on the green sheet 20 that is the basis of the even-numbered dielectric layer 2 counted from the upper surface side. And it forms so that the area | region which apply | coated the conductive paste 40 for conductor wiring of the green sheet 20 used as the basis of the odd-numbered dielectric layer 2 counted from the upper surface side of the dielectric block 1 may be formed.

  In addition, the through hole 16 is a central portion of the region 14 of the dielectric sheet 1 where the conductive paste 40 for conductor wiring is not applied on the green sheet 20 that is the basis of the odd-numbered dielectric layer 2 counted from the upper surface side. And is formed so as to overlap with a region where the conductive paste 30 for conductive wiring is applied on the green sheet 20 which is the basis of the even-numbered dielectric layer 2 counted from the upper surface side of the dielectric block 1. To do.

  The laser irradiation is trepan processing, that is, the diameter of the laser is set to be smaller than the diameter of the through holes 15 and 16 to be formed, and the irradiation is repeated to form the through holes 15 and 16 having a predetermined diameter. Is preferred.

  Specifically, first, the central through-holes 15a and 16a are formed by irradiating the laser La to the substantially central portion of the region to be the through-holes 15 and 16 (FIG. 4A).

  Next, while moving the irradiation position around the central through-holes 15a and 16a, the laser Ln is gradually irradiated outward in a spiral shape to the peripheral through-holes to the peripheral positions of the regions to be the through-holes 15 and 16. Open 15n and 16n (FIG. 4 (b)).

  Then, by repeating this operation, the through holes 15 and 16 having a predetermined diameter are formed (FIG. 4C).

  When the above operation is performed, even when the number of green sheets 20 forming the stacked body 11 is 100 or more, the heat generated by the irradiation of the laser Ln moves up and down through the central through holes 15a and 16a. Dissipated.

  Therefore, the exposed portions of the conductive wiring conductive pastes 30 and 40 exposed in the through holes 15 and 16 are evaporated by the heat, and the internal electrodes 3 and 4 and the via conductors 5 and 6 are removed. It is possible to prevent the problem that the conductive connection cannot be made satisfactorily.

  And since the conductive pastes 50 and 60 for via conductors can be filled in the said through-holes 15 and 16 in the state which exposed the conductive pastes 30 and 40 for conductor wiring in the through-holes 15 and 16, after that, As a result of the firing, the internal electrodes 3 and 4 and the via conductors 5 and 6 can be electrically conductively connected.

  The pulse frequency of the laser is preferably 1 to 30 kHz (pulse period 0.03 to 1 ms).

  When the pulse frequency is less than 1 kHz, it takes a long time for laser drilling, and the productivity may decrease.

  In addition, when the pulse frequency exceeds 30 kHz, the amount of heat generated by laser irradiation becomes large, and there is a possibility that the problem associated with the evaporation of the conductive pastes 30 and 40 for conductor wiring described above may occur.

  When the through-holes 15 and 16 are formed by laser irradiation, it is preferable to evacuate and remove decomposition products of organic substances such as organic binder resin, and separated ceramic powder.

  The through holes 15 and 16 may be formed by drilling or punching using a micro drill.

  The laminated body 11 in which the through holes 15 and 16 are formed is preferably removed by removing the remaining processing waste by immersing in water and ultrasonically washing.

  Next, via conductors 50 and 60 are filled in the formed through holes 15 and 16 by screen printing or the like (FIG. 3E).

  Then, the conductive paste 40 for conductor wiring applied to the surface of the green sheet 20 that is the basis of the odd-numbered dielectric layer 2 counted from the upper surface side of the dielectric block 1 exposed in the through hole 15; It will be in the state which the conductive paste 50 for via conductors filled in the through-hole 15 contacted.

  Conductive paste 30 for conductor wiring applied to the surface of the green sheet 20 that is the basis of the even-numbered dielectric layer 2 counted from the upper surface side of the dielectric block 1 exposed in the through hole 16; It will be in the state which the conductive paste 60 for via conductors filled in the through-hole 16 contacted.

  Next, as described above, in the case where one green sheet 20 is formed to have a size including a plurality of regions corresponding to one dielectric layer 2, the stacked body 11 For each area, for example, it is cut out by using a push cut. When the thickness of the laminated body 11 is large, it may be cut out by dicing.

  Thereafter, the laminated body cut out is placed in, for example, a heating furnace and heated to 250 to 400 ° C. to remove the organic binder resin and other organic substances, and then placed in a main firing furnace to 1250 to 1300 ° C. After the dielectric block 1 shown in FIG. 1 is formed by heating and firing, external electrodes 7 and 8 are formed on the surface of the dielectric block 1 to produce the multilayer ceramic capacitor 10 shown in FIG.

  The configuration of the present invention is not limited to the above-described embodiments, and various changes and improvements can be made without departing from the scope of the present invention.

  For example, a plurality of via conductors 5 and 6 may be formed in the dielectric block 1.

  Thereby, the multilayer ceramic capacitor 10 with little parasitic inductance can be provided.

  A plurality of electrically independent capacitors may be formed in one dielectric block 1. For example, capacitors having different capacities with different areas of the internal electrodes 3 and 4 functioning as individual capacitors may be incorporated in the same dielectric block 1.

  It goes without saying that the configuration of the present invention can be applied to a ceramic wiring board that forms electronic components other than the multilayer ceramic capacitor 10.

<< Preparation of conductive paste for via conductor >>
As the Ni powder, the average particle diameter is 6.7 μm, and the surface thereof is the first Ni powder coated with the NiO layer, and the average particle diameter is 0.9 μm, and the surface is the NiO layer. And a second Ni powder coated with. The blending ratio of both was 33 parts by weight of the second Ni powder with respect to 100 parts by weight of the first Ni powder.

  The average thickness of the NiO layer covering the surface of the Ni powder was set to the same thickness for the two types of Ni powders to be combined, and four types of 0.7 nm, 2 nm, 15 nm, and 25 nm were used.

As the Cu powder, one having an average particle diameter of 0.1 μm and a surface coated with an SiO ₂ layer was used.

The average thickness of the SiO ₂ layer covering the surface of the Cu powder was 4 types of 3 nm, 7 nm, 40 nm, and 60 nm.

A conductive paste for via conductors was prepared by mixing a mixture of the above two kinds of Ni powder, Cu powder, and BaTiO ₃ as a ceramic component with an organic binder resin and a solvent. As Ni powder and Cu powder, as shown in Table 1, NiO layers and SiO ₂ layers having different average thicknesses were combined. The volume ratio Va of the Cu powder was 0.03, the volume ratio Vb of the mixture of Ni powder was 0.97, and the volume ratio Vc of the ceramic component was 0.15. Actually, the blending amount of each component obtained by weight conversion from the specific gravity of each component was measured so that the volume ratio of each component was the above value.

《Formation of via conductor》
A conductive paste for conductive wiring containing Ni is applied by screen printing to the surface of a 0.7 μm thick green sheet containing BaTiO ₃ as a main component of the ceramic component and MgTiO ₃ as a subcomponent. A composite sheet was prepared, and a plurality of the composite sheets were stacked to form a laminate. Next, a through hole having a diameter of 100 μm was formed at a predetermined position of the laminated body, and the above conductive paste for via conductor was filled.

A ceramic wiring board model was prepared by firing for 24 hours from entry to exit at a peak temperature of 1310 ° C., then polishing until the via conductor was exposed, observing the via conductor, and its electrical resistance Was measured. The results are shown in Table 1.

  In Table 1, * 1) means that a portion of the via conductor away from the through hole was seen. * 2) means that the via conductor was found to have a winding shape. * 3) means that the electrical resistance of the via conductor has increased and the conductivity has decreased.

From Table 1, the average thickness of the NiO layer covering the surface of the Ni powder is preferably 1.0 to ₂₀ nm, and the average thickness of the SiO ₂ layer covering the surface of the Cu powder is 5.0 to 50 nm. It turned out to be preferable.

It is sectional drawing which shows the laminated ceramic capacitor as an example of the ceramic wiring board of this invention by which the via conductor was formed using the conductive paste for via conductors of this invention.

It is sectional drawing which shows the process of manufacturing the multilayer ceramic capacitor of FIG. 1 with the manufacturing method of this invention.

It is sectional drawing which shows the process of manufacturing the multilayer ceramic capacitor of FIG. 1 with another manufacturing method of this invention.

FIG. 4 is a perspective view showing a step of forming a through hole in a stacked green sheet in the manufacturing method of FIG. 3.

It is sectional drawing which shows the laminated ceramic capacitor as an example of the conventional ceramic wiring board.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Dielectric block 2 Dielectric layer 3, 4 Internal electrode 5, 6 Via conductor 7, 8 External electrode 10 Multilayer ceramic capacitor (ceramic electronic component)
11 Laminated bodies 13 and 14 Regions without electrodes (regions where coating is not performed)
15, 16 Through hole 20 Green sheet 30, 40 Conductive paste 50 for conductor wiring, 60 Conductive paste for via conductor

Claims (10)

A conductive paste for via conductor filled in a through-hole formed in a green sheet containing a ceramic component and fired with the green sheet to form a via conductor, a Cu powder having a glass layer on the surface, and a metal on the surface A conductive paste for via conductors, comprising Ni powder having an oxide layer, and a ceramic component having the same quality as the ceramic component contained in the green sheet. 2. The via conductor according to claim 1, wherein the volume ratio Va of the Cu powder, the volume ratio Vb of the Ni powder, and the volume ratio Vc of the ceramic component satisfy all of the expressions (1) to (5). Conductive paste.
0.01 ≦ Va ≦ 0.1 (1)
0.9 ≦ Vb ≦ 0.99 (2)
0.01 ≦ Vc ≦ 0.3 (3)
Va + Vb = 1 (4)
1.01 ≦ Va + Vb + Vc ≦ 1.3 (5) The average thickness of the glass layer on the surface of the Cu powder is 5.0 to 50 nm, and the average thickness of the metal oxide layer on the surface of the Ni powder is 1.0 to 20 nm. Conductive paste for via conductor. The average particle size of Cu powder is 0.1 to 1.0 μm, the average particle size of Ni powder is 0.1 to 10 μm, and the average particle size of ceramic components is 0.1 to 1.0 μm. Item 2. The conductive paste for via conductors according to Item 1. The conductive paste for via conductors according to claim 4, wherein two kinds of Ni powders having different average particle diameters are used in combination as the Ni powder. A ceramic wiring board comprising via conductors formed by firing the conductive paste for via conductors according to claim 1. A step of forming a through hole in the green sheet, a step of filling the formed through hole with the conductive paste for via conductor according to claim 1, and forming a conductor wiring by firing, for a conductor wiring containing Ni as a conductive component Applying a conductive paste to the surface of the green sheet so that a part of the conductive paste is in contact with the conductive paste for via conductors filled in the through-holes, and for green sheet, conductive paste for via conductors, and conductor wiring And a step of firing the conductive paste at the same time. It includes a step of filling a plurality of green sheets filled with conductive paste for via conductors in the through-holes and coated with conductive paste for conductor wiring on the surface, before firing. The method for producing a ceramic wiring board according to claim 7, wherein the ceramic wiring board is integrated. A process of applying conductive paste for conductive wiring containing Ni as a conductive component, which forms conductive wiring by firing, on the surface of the green sheet so that a part thereof overlaps the region of the green sheet where the through hole is formed. And forming a through hole in the green sheet and removing the conductive paste for conductor wiring that overlaps the through hole, and part of the conductive paste for conductor wiring applied to the surface of the green sheet in the formed through hole And the step of filling the conductive paste for via conductors of claim 1 so as to be in contact with the conductive paste, and the step of simultaneously firing the conductive paste for via conductors and the conductive paste for conductive wiring. A method for manufacturing a ceramic wiring board. Including a step of stacking a plurality of green sheets coated with a conductive paste for conductor wiring on the surface before forming the through-holes, forming a through-hole by penetrating the plurality of stacked green sheets, and via conductors The method for producing a ceramic wiring board according to claim 9, wherein after the conductive paste is filled, the plurality of stacked green sheets are integrated by firing.

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