JP2005243789A - Method of manufacturing ceramic component - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a ceramic component whereby it is possible to prevent a defect such as swelling, a crack or the like, from being generated at a conductor pattern or a via hole conductor that constitutes a ceramic component, when manufacturing the same. <P>SOLUTION: A conductor containing at least metal powder and carbon powder is formed on the surface of or inside a ceramic mold that includes ceramic powder and an organic binder, and then the conductor is calcined after the organic binder is removed. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method for producing a ceramic electronic component, and more particularly to a method for producing a ceramic electronic component that is fired after forming a conductor portion containing at least a metal powder on the surface or inside of a ceramic molded body containing ceramic powder and an organic binder. It is.

  Conventionally, ceramics typified by alumina, barium titanate, or manganese zinc spinel function by forming a conductor on at least the surface of these ceramics because of their high insulation, high dielectric properties, and high magnetism. It is applied as an electronic component.

  In recent years, new ceramics such as glass ceramics containing alumina and silica have been developed, starting with alumina. Such new materials are suitable as multilayer wiring boards for semiconductor element storage packages as the semiconductor industry develops. Has been used.

A multilayer wiring board using such glass ceramics as an insulating substrate has a conductor part such as a conductor pattern or a via hole conductor formed on the surface or inside of a ceramic grease sheet containing glass ceramic raw material powder, and then a ceramic green sheet is formed. A plurality of layers are laminated, and the conductor part and the ceramic green sheet are integrally fired (for example, Patent Document 1). Incidentally, the conductor pattern and via-hole conductor for forming such a multilayer wiring board are, for example, metal powder such as copper powder and glass powder such as ZnO, SiO ₂ and B ₂ O _{3 in addition} to the predetermined powder. It is blended and prepared in proportions.
JP-A-6-26873

  However, multilayer wiring boards such as packages for housing semiconductor elements are becoming thinner and finer in line with the recent demand for higher density, and as a result, in such ceramic electronic components, the proportion of wiring in the insulating board is increased. Increasing year by year, the influence of conductor parts such as conductor patterns and via-hole conductors on the characteristics of ceramic electronic components cannot be ignored.

  In other words, the conductor part constituting the ceramic electronic component has been adjusted in addition amount to prevent an increase in resistance value and a decrease in plating performance due to the addition of filler components such as glass powder and metal oxide. The sintering behavior of porcelain changes due to the diffusion of filler components such as glass powder and metal oxides from, and the degreasing failure is liable to occur due to the softened glass powder. There was a problem that defects called blisters occurred.

  As for the via-hole conductor, when the filler such as glass powder or metal oxide is added to the copper powder as described above, when the copper in the via-hole conductor diffuses to the porcelain side, There was a problem that cracks occurred in the surrounding porcelain. FIG. 2 is a schematic diagram showing a bulge 21, a separation 22, and a crack 23 generated when the ceramic molded body 20 that becomes a multilayer wiring board after firing is fired.

  Accordingly, an object of the present invention is to provide a method for producing a ceramic electronic component capable of preventing the occurrence of defects such as blisters and cracks occurring in a conductor pattern and a via-hole conductor constituting the ceramic electronic component. .

  In the method for producing a ceramic electronic component according to the present invention, a conductor part containing at least metal powder and carbon powder is formed on the surface or inside of a ceramic molded body containing ceramic powder and an organic binder, and the organic binder is removed and then fired. It is characterized by.

  In the manufacturing method of the ceramic electronic component, the conductor portion is a conductor pattern formed on the surface of the ceramic molded body, the conductor portion is a via-hole conductor formed inside the ceramic molded body, and included in the conductor portion. The content of the carbon powder is preferably 0.05 to 10 parts by mass per 100 parts by mass of the metal powder, and the average particle size of the carbon powder is preferably 1 to 5 μm.

  In the method for producing a ceramic electronic component, the ceramic molded body is a laminate of ceramic green sheets, the ceramic green sheet preferably contains glass powder and filler, and the metal powder is preferably Cu or Ag, or an alloy thereof. .

  According to the method for producing a ceramic electronic component of the present invention, when the conductor part is formed on the ceramic molded body, a glass powder contained in the conductor part at the time of firing is obtained by including carbon powder together with the metal powder in the conductor paste. Degreasing failure due to diffusion and softening of filler components such as metal oxides and metal oxides can be suppressed, thereby preventing a so-called swollen defect that occurs in the ceramic part and conductor part of the ceramic electronic component after firing.

  In addition, in the via hole conductor, when the ceramic molded body and the via hole conductor are simultaneously fired, the abnormal shrinkage behavior at the time of firing the ceramic molded body can be suppressed by including carbon powder in the via hole conductor. Cracks generated around the via-hole conductor after firing can be prevented.

  Further, according to the present invention, the amount of carbon powder contained in the conductor portion is set to 0.05 to 10 parts by mass per 100 parts by mass of the metal powder, whereby the amount of firing shrinkage between the ceramic molded body and the conductor part is made closer. In addition, the density of the conductor after firing can be maintained high.

  Furthermore, according to the present invention, by setting the average particle size of the carbon powder to 1 to 5 μm, the degree of dispersion of the carbon powder in the conductor portion can be increased, and formation of local voids and the like can be prevented.

  Next, as described above, the production method of the present invention is effective in countermeasures against defects such as degreasing defects due to diffusion and softening of filler components such as glass powder and metal oxide contained in the conductor during firing. As a ceramic molded body applied to this manufacturing method, it is desirable that it is a laminated body of ceramic green sheets that can have a conductor portion as an inner layer.

  In other words, the production method of the present invention is suitable for a ceramic green sheet containing glass powder and filler that are easily diffused and softened.

  Moreover, in this invention, it is desirable that it is Cu or Ag, or these alloys as a metal powder which can be cofired with the ceramic green sheet containing the above-mentioned glass powder.

  And by setting it as the structure of an above-described conductor part and a ceramic green sheet, the sinterability of metallization can be improved, without raising the resistance value of metallization or degrading plating property.

  A method for producing a ceramic wiring board, which is a representative example of the ceramic electronic component of the present invention, will be described in detail with reference to the process diagram of FIG.

(A) First, a glass composition and a ceramic filler are mixed to prepare a ceramic composition, an organic binder is added to the mixture, and then a ceramic green sheet 1 is produced by a doctor blade method, a rolling method, a pressing method, or the like. To do.

  The ceramic composition used here is preferably a borosilicate glass powder in that it is easily crystallized at the time of firing and a low thermal expansion coefficient, high strength, and a low dielectric constant can be obtained. As the ceramic filler, it is preferable to use, for example, 0.5 to 20% by mass of cordierite powder and 0 to 35% by mass of metal oxide powder as the ceramic filler.

Further, silicate glass powder towards the _above, SiO 2 20 to 53 _{wt%, Al} 2 O 3 _5~61 wt%, MgO 2 to 24 wt%, ZnO 2 to 14 _{wt%, B} 2 O 3 _2~14 mass %, BaO 3 to 40% by mass, and as an optional component, at least one selected from the group of CaO, SrO and ZrO ₂ is preferably contained in an amount of 0 to 15% by mass.

Furthermore, the metal oxide powder is at least one selected from the group consisting of alumina, garnite, spinel, mullite, forsterite, enstatite, anosite, slausonite, serdian, zirconia, CaZrO ₃ , CaSiO ₃ , and quartz glass. It is desirable.

(B) Next, the through-hole 3 having a diameter of 80 to 200 μm is formed in the produced ceramic green sheet 1 by laser, micro drill, punching or the like. And since the manufacturing method of this invention can improve the flatness of a via-hole conductor, it can be used suitably even if the pitch of the through-hole 3 is 500 micrometers or less and a narrow pitch.

(C) Next, the through-hole 3 is filled with a conductor paste to form a via-hole conductor 5 which is one of the conductor portions of the present invention. It is important that the conductor paste of the present invention contains a copper powder, a glass component, and a carbon powder as a solid content. An organic resin such as an acrylic resin and an organic solvent such as α-terpineol are homogeneously mixed with the solid content.

(D) Next, on the surface of the green sheet 1, a conductor pattern 7 that is also a conductor portion is formed on the surface of the green sheet 1 by using a method such as screen printing with a conductor paste containing the copper powder a as with the via-hole conductor 5.

  The conductor paste for the conductor pattern 7 and the via-hole conductor 5 contains 4 to 20 parts by mass of an inorganic component such as glass and 0.05 to 10 parts by mass of carbon powder with respect to 100 parts by mass of the copper powder a copper powder. It is preferable that the average particle diameter is 3 to 6 μm, the average particle diameter of the inorganic component is 1.5 to 5 μm, and the average particle diameter of the carbon powder is 1 to 5 μm. The components of the organic resin and the organic solvent and the addition amount thereof are preferably the same as those for the via-hole conductor 5 because the degreasing speed is close to that of the via-hole conductor 5.

  Moreover, in this invention, the wiring pattern 7 formed by carrying out the photolithography process of metal foil other than using said conductor paste can also be used as the conductor pattern 7 at the point that a higher dimensional accuracy can be achieved.

(E) Next, a plurality of ceramic green sheets 1 produced in the same manner as described above are laminated and pressure-bonded to form a laminate 9. For the lamination in this case, a method of applying heat and pressure to the stacked ceramic green sheets 1 and thermocompression bonding, a method of applying an adhesive composed of an organic resin, a plasticizer and an organic solvent between the sheets, and the like are adopted. Is possible.

  Next, after heat-treating the laminated body 9 in a nitrogen atmosphere containing water vapor at 500 to 700 ° C. to remove the organic resin, the laminate 9 is fired in a non-oxidizing atmosphere such as nitrogen at 850 ° C. to 1050 ° C. Baking until the substrate is densified to a relative density of 90% or higher. Thereafter, a plated layer of Cu, Au, Ni or the like is formed on the metallized wiring on the surface of the ceramic wiring substrate by an electrolytic plating method or an electroless plating method, thereby completing the ceramic wiring substrate. The ceramic wiring board of the present invention includes an insulating substrate 31 comprising a plurality of insulating layers 31a to 31c formed by simultaneously firing the green sheet 1, the wiring pattern 7 and the via hole conductor 5, respectively, a metallized wiring 33, and via hole baking. The conductor 35 is constituted.

  The multilayer wiring board was evaluated as an example for the method for producing the ceramic of the present invention.

First, as a ceramic green sheet for the insulating substrate, a glass composition of _{44% SiO 2 -36% BaO-} 7% B 2 O 3 -8% Al 2 O 3 -5% CaO in the mass ratio (sag point 700 ° C.) A mixture containing 45% by volume of SiO ₂ as a filler component with respect to 55% by volume was used. An acrylic binder, a plasticizer, a dispersant, and a solvent were added thereto and mixed, and the slurry was formed into a ceramic green sheet having an average thickness of 200 μm by a doctor blade method.

  As the conductive paste for the conductive pattern, copper powder having an average particle diameter of 5 μm was used, and carbon powder (carbon black, purity 99.7%) having an average particle diameter of 5 μm was added in various amounts. Further, a predetermined amount of an organic vehicle was added thereto to prepare a paste composition. The paste was printed on the surface of the ceramic green sheet to form a conductor pattern.

  As the conductor paste for the via-hole conductor, copper powder having an average particle diameter of 5.1 μm was prepared. And with respect to 100 mass parts (Cu conversion) with respect to these copper powders, the same carbon powder as used for the said conductor pattern whose average particle diameters are 3 micrometers and 5 micrometers was prepared, and it added by the ratio shown in Table 1. Further, glass powders having an average particle diameter of 1.5 μm and a softening point of 840 ° C. were weighed and added in the proportions shown in Table 1, respectively. Further, 10 parts by mass of acrylic resin as an organic resin and 10 parts by mass of α-terpineol as an organic solvent were added to 100 parts by mass of these solid contents, and kneaded to prepare a conductor paste for via-hole conductors.

  Next, the green sheet is drilled and filled into a via hole using the above-described conductor paste to form a via-hole conductor having a diameter of 200 μm after firing, and then the green sheet on which the via-hole conductor is formed is formed. This time, the conductor paste for the conductor pattern is printed on the surface to form a conductor pattern, and thus four ceramic green sheets on which via-hole conductors and conductor patterns are formed so as to have a desired arrangement and pattern shape, respectively. Was laminated by pressure to produce a laminate 9. In this example, the evaluation of the via-hole conductor is based on Sample No. Based on the sample of 5, a sample for via hole conductor evaluation was prepared and evaluated.

  Next, in order to decompose and remove organic components such as an organic binder, the laminate was degreased by holding at 750 ° C. for 1 hour in a steam-containing nitrogen atmosphere, and then heated to 900 ° C. in a nitrogen atmosphere. For 1 hour to produce a ceramic wiring board. The thickness of the conductor pattern was 15 μm.

The results are shown in Table 1. A stereomicroscope was used to evaluate the cracks and swelling of the insulating substrate around the via-hole conductor. As for the plating property, a 10 mm square pattern was printed and plating was performed.

As is apparent from Table 1, sample No. using a metallized paste containing no carbon. In No. 1, there was swelling. Further, No. 1 to which a metal oxide was added. Although No. 2 did not swell, the resistance increased to 4.5 mΩ / □ (sheet resistance: measurement resistance × (measurement length / width)), and the plating property also decreased. On the other hand, the present sample No. In 3 to 10, there was no occurrence of swelling, and the specific resistance and plating property were also good.

  Further, as is apparent from the results in Table 2, the sample No. 1 containing no carbon in the via-hole conductor was used. In No. 11, a crack occurred in the substrate.

  On the other hand, according to the present invention, sample No. 1 containing carbon in the via-hole conductor was used. In 12-20, there was no crack.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic diagram which shows the ceramic molded body concerning the manufacturing method of the ceramic electronic component of this invention, (a) is the ceramic molded body which comprises a conductor layer on the surface, (b) is laminated | stacked several ceramic green sheet. And a via hole conductor on the surface and inside of the laminate formed in this manner. It is a schematic diagram which shows the swelling, peeling, and crack which generate | occur | produce when baking the ceramic molded body used as a multilayer wiring board after baking.

Explanation of symbols

1 Ceramic green sheet 5 Via-hole conductor (conductor part)
7 Conductor pattern (conductor part)
9 Laminate

Claims (8)

A method for producing a ceramic electronic component, comprising: forming a conductor part containing at least a metal powder and a carbon powder on a surface or inside of a ceramic molded body containing a ceramic powder and an organic binder; and firing after removing the organic binder. 2. The method of manufacturing a ceramic electronic component according to claim 1, wherein the conductor portion is a conductor pattern formed on the surface of the ceramic molded body. The method for producing a ceramic electronic component according to claim 1, wherein the conductor portion is a via-hole conductor formed inside the ceramic molded body. The method for producing a ceramic electronic component according to any one of claims 1 to 3, wherein the content of the carbon powder contained in the conductor part is 0.05 to 10 parts by mass per 100 parts by mass of the metal powder. The method for producing a ceramic electronic component according to claim 1, wherein the carbon powder has an average particle size of 1 to 5 μm. The method for producing a ceramic electronic component according to claim 1, wherein the ceramic molded body is a laminate of ceramic green sheets. The method for producing a ceramic electronic component according to claim 1, wherein the ceramic green sheet contains glass powder and a filler. The method for producing a ceramic electronic component according to any one of claims 1 to 7, wherein the metal powder is Cu or Ag, or an alloy thereof.

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