JP4953626B2 - Manufacturing method of ceramic electronic component - Google Patents

Description

  The present invention relates to a method of manufacturing a ceramic electronic component formed by printing a conductor layer on a surface of a support in a ceramic electronic component such as a multilayer ceramic wiring board.

  In recent years, with the miniaturization of electronic devices, there is a demand for miniaturization and high performance in ceramic electronic components such as multilayer ceramic wiring boards used in the electronic devices. For example, in a multilayer ceramic wiring board, in order to reduce the size and increase the density of wiring conductors, thinner insulating layers and wiring conductor layers are formed in multiple layers, and the width, spacing and through-holes of the wiring conductor layers are finer. Is required.

As a method for producing such a ceramic electronic component, a flat sheet is formed by printing a ceramic slurry on a support having a conductor layer formed on the surface as described in Patent Document 1, drying, and then peeling. A manufacturing method for forming the film has been proposed. According to this manufacturing method, since delamination is less likely to occur due to non-uniform pressure when the green sheets are laminated, electrical characteristics can be ensured. Further, when a large number of green sheets on which conductor layers are formed are laminated, lamination can be performed at a low pressure, so that lamination deformation can be suppressed and high dimensional accuracy of the ceramic laminate can be ensured.
Japanese Patent Laid-Open No. 50-64768

  However, in a manufacturing method in which a flat sheet is formed by applying a ceramic slurry on a support having a conductor layer formed on the surface and peeling it off after drying, a portion where the conductor layer is formed overlaps with a portion where it does not overlap. Since there is no difference in thickness and the green sheets will be in close contact with each other, the ceramic electronic component obtained by firing the ceramic laminate will have less delamination, but after forming the conductor layer on the support When the ceramic slurry is applied, the ceramic slurry and the conductor layer are dissolved, mixed, and made identical to each other, and the conductor width is wider than the actually designed width (hereinafter also referred to as “brightening”). For this reason, if there is a bleed in the conductor as described above inside the electronic component, the electrical capacitance value and the resistance value deviate from the actual design values. Therefore, the electronic component manufactured by the above manufacturing method has electrical characteristics. There was a problem that the standard value could not be satisfied.

  On the other hand, in a production method in which a flat sheet is formed by applying a ceramic slurry on a support having a conductor layer formed on the surface and peeling it after drying, the conductor layer and the ceramic slurry are affected by the expansion and contraction of the support. When a support having a large thermal expansion is used, the conductor and the ceramic slurry expand following the expansion of the support during drying, and the conductor width and pitch are wider than those actually designed (hereinafter also referred to as dimensional deviation). ). If there is a defect or dimensional deviation of the conductor as described above inside the electronic component, the electrical capacity value or resistance value deviates from the actual design value. Therefore, the electronic component manufactured by the above manufacturing method has electrical characteristics. There was a problem that it was not possible to satisfy the standard value.

  The present invention has been devised in view of the above-described problems, and the occurrence of delamination can be effectively suppressed, a conductor with high dimensional accuracy can be formed, and a ceramic electronic component having high electrical characteristics can be obtained. An object of the present invention is to provide a method for manufacturing a ceramic electronic component.

The method for producing a ceramic electronic component of the present invention is a method for producing a ceramic electronic component in which a conductor is formed by printing a conductor paste on the surface of a support, and the conductor layer is coated on the support by applying the conductor paste. Step A for forming, Step B for obtaining a ceramic green sheet with a conductor layer by applying a ceramic slurry on the support on which the conductor layer has been formed to form a ceramic green sheet layer and drying, and the conductor layer Forming a ceramic laminate by drilling a through hole in the attached ceramic green sheet and filling the through hole with a conductive paste; and forming a ceramic laminate by laminating a plurality of the ceramic green sheets with the conductor layer while heating And ceramic ceramic component manufacturing method including the step E of firing the ceramic laminate. The difference between the solubility parameter of the slurry and the solubility parameter of the conductor layer is 1.0 to 7.0, wherein the support is prepared by heat treatment of 70 to 170 ° C., in the planar direction before and after the time of the drying The dimensional change rate is within 0.1%.

  The method for manufacturing a ceramic electronic component according to the present invention is characterized in that the support includes a UV absorber, and the through hole is formed by irradiation with a YAG laser in the step C. is there.

  Further, in the method for manufacturing a ceramic electronic component of the present invention, the step B includes a step of forming a second ceramic green sheet layer containing a melting component that melts by heating in the step D on the ceramic green sheet layer. It is characterized by including.

  In the method for manufacturing a ceramic electronic component according to the present invention, the second ceramic green sheet layer is formed by applying the second ceramic slurry onto the ceramic slurry applied in the step A and drying it. The difference between the solubility parameter of the ceramic slurry and the solubility parameter of the second ceramic slurry is 2 or more.

  Furthermore, in the method for producing a ceramic electronic component of the present invention, the second ceramic green sheet layer is formed on the ceramic green sheet layer and heated in the step B, and the molten component is It becomes a molten state by the heating in the process B and the process D.

In the method for producing a ceramic electronic component according to the present invention, the melting point of the molten component is in the range of 35 to 100 ° C.

  In the method of manufacturing a ceramic electronic component according to the present invention, the YAG laser is a third harmonic YAG laser, and the 90% particle size (D90) in the number cumulative particle size distribution of the ceramic powder contained in the ceramic green sheet is It is 10 μm or less.

According to the method for producing a ceramic electronic component of the present invention, a conductor layer is formed with a conductor paste on a support, a ceramic slurry is applied on the support to form a ceramic sheet, and the conductor layer is dried. Since the difference between the solubility parameter of the ceramic slurry and the solubility parameter of the conductor layer is set to 1.0 to 7.0 in the step of forming the ceramic green sheet with the conductor layer made of the ceramic green sheet, the ceramic slurry and the conductor layer Are dissolved in each other and mixed, and it is possible to prevent the conductor from blurring without being equalized, and when the ceramic green sheet on which the conductor layer is formed is peeled off from the support, the peeling of the conductor layer from the ceramic green sheet Defects can be prevented.

  In addition, according to the method for manufacturing a ceramic electronic component of the present invention, the processing for subjecting the ceramic green sheet with a conductor layer to through-hole processing is performed by irradiation with a YAG laser and the support is made to contain a UV absorber. In this case, the laser irradiation spot diameter can be reduced to about 50 μm, and the support contains a UV absorber and is efficiently processed by absorbing the laser. Sheets can be simultaneously drilled at the same time, and the through holes can have a small diameter of, for example, 50 μm or less.

Furthermore, according to the method for manufacturing a ceramic electronic component of the present invention, the method includes the steps of forming a conductor layer with a conductor paste on a support and forming a ceramic green sheet on the support on which the conductor layer is formed. Therefore, there is little difference in thickness between the area where the conductor layer is formed and the area where it is not, and the ceramic green sheets are brought into close contact with each other without generating voids around the conductor layer or between the conductor layers, and the ceramic laminate is fired. The ceramic electronic component obtained in this way has almost no delamination. In addition, ceramic green sheets can be laminated at a low pressure, and the ceramic green sheets and the conductor pattern formed thereon are hardly deformed. The resulting ceramic laminate and ceramic electronics obtained by firing the ceramic laminate are obtained. The parts have high dimensional accuracy.

  In this case, since the second ceramic green sheet layer contains a melting component that melts when heated, there is no need to apply high pressure when laminating the ceramic green sheets, and the laminated ceramic green sheets are misaligned. What is necessary is just to laminate | stack by the pressure of the grade which does not. Accordingly, there is no deformation due to the lamination pressure, and high dimensional accuracy can be maintained.

  Here, since the first ceramic green sheet layer does not contain a melting component that melts when heated, the first ceramic green sheet hardly deforms when heated, and the laminated ceramic green sheets at the time of lamination. Is not greatly deformed by a pressure that can be pressed so as not to be displaced. Therefore, since the shapes of the first ceramic green sheet layer and the conductor layer are satisfactorily maintained, the resulting ceramic laminate and the ceramic electronic component obtained by firing the same are effectively prevented from delamination, and It has high dimensional accuracy.

  Further, according to the method for manufacturing a ceramic electronic component of the present invention, when the melting component of the melting component that melts when heated is 35 ° C. to 100 ° C., the second ceramic green sheet layer is softened at room temperature. Since there is almost no deformation, handling up to the lamination process is easy, and organic components such as organic binders and plasticizers in the ceramic green sheet are not decomposed during heating, so delamination caused by decomposition gas Is effectively prevented.

Furthermore, when manufacturing a ceramic electronic component having a cavity, it is not necessary to press the ceramic green sheet with a large pressure, so that the cavity bottom due to the difference in elongation of the ceramic green sheet due to the pressurization between the cavity periphery and the cavity bottom. The generation of warpage can be effectively suppressed, and a ceramic electronic component can be obtained in which an electronic element can be mounted accurately and reliably on the bottom of the cavity.

  Furthermore, according to the method for manufacturing a ceramic electronic component of the present invention, when the through hole processing is performed on the ceramic green sheet with the conductor layer using a third harmonic YAG laser, the irradiation spot diameter of the laser is reduced. It can be further reduced to about 30 μm, and the through hole can have a smaller diameter of, for example, 30 μm or less.

  Further, when the 90% particle size (D90) in the number cumulative particle size distribution of the ceramic powder contained in the ceramic green sheet is 10 μm or less, the ceramic powder contained in the ceramic green sheet becomes a third harmonic YAG laser. When the ejected gas from the support that has volatilized is discharged so as to be physically ejected from the inside of the through hole, the size of the ceramic powder desorption marks on the side surface of the through hole is reduced, and The uneven shape of the side surface can be made flatter. As a result, when the conductor paste is filled in the through hole, there is no gap between the through hole and the filled conductor paste, and a ceramic electronic component with high conduction reliability is obtained.

  As described above, according to the method for manufacturing a ceramic electronic component of the present invention, since there are no gaps between insulating layers and deformation of the insulating layer and the conductor layer is small, delamination hardly occurs and high dimensional accuracy is obtained. In addition, a high-quality ceramic electronic component capable of forming a highly accurate pattern is obtained.

  The method for producing a ceramic electronic component of the present invention will be described in detail below.

Figure 1 is a sectional view of each process showing an example of an embodiment of a manufacturing method of a ceramic electronic component of the present invention, 1 is a support, 2 conductor layer, 3 is a ceramic green sheet (hereinafter, also green sheet say.), 4 ceramic green sheets (hereinafter with conductive layers, also referred to as a conductor with the green sheet.), 5 is a ceramic laminate.

  First, as shown in FIG. 1 (a), a conductor layer 2 is formed on a support by a conductor paste, and further, as shown in FIG. 1 (b), a ceramic slurry is formed on the support 1 on which the conductor layer 2 is formed. Thus, the green sheet 3 is formed.

The support 1 is a resin molded product that does not penetrate a solvent, and is a polyester resin such as polyethylene terephthalate (PET) or polybutylene terephthalate-isophthalate copolymer conventionally used, such as polyethylene, polypropylene, and polymethylpentene. A resin molding using a resin such as a polyolefin resin, a polyfluorinated ethylene resin, a cellulose resin, or an acrylic resin can be used.

  A release layer may be formed on the surface of the support 1 on which the conductor layer 2 is formed in order to improve the peelability from the support 1 after the green sheet 3 is formed. The types of release layers are broadly classified into silicone release agents and non-silicone release agents, and fluorine-based release agents can be used as the non-silicone release agents. As the release agent, any of a solventless type, an emulsion type, and a solvent type can be used depending on the product form. The thickness of the release layer varies depending on the type of release agent used, but the green sheet 3 can be peeled off from the support 1 and repelling of the conductor paste occurs when the conductor layer 2 is formed by the release agent. It is sufficient if the thickness is such that it does not.

  The thickness of the support 1 is suitably 10 to 100 μm, preferably 20 to 50 μm. This is because if the thickness of the support 1 is less than 10 μm, the conductor pattern formed by deformation or bending of the film tends to cause disconnection or peeling, and if the thickness is greater than 100 μm, it is difficult to drill through holes.

The dimensional change rate in the dry before and after the ceramic slurry and the conductive paste support 1 Ru der within 0.1%. This dimensional change rate is an important factor in forming the conductor layer 2 and the green sheet 3 on the support 1 in order to reduce the variation between the wiring pitches of the fine wiring and enable the fabrication with high dimensional accuracy. If the dimensional change rate in the planar direction of the support 1 is greater than 0.1%, it becomes impossible to manufacture a multilayer ceramic wiring board with high dimensional accuracy.

  Such a support 1 having a small elongation can be produced by performing a predetermined heat treatment (annealing). Specifically, although the temperature of the heat treatment depends on the material of the film, it is preferably in the range of 70 to 170 ° C, preferably 100 to 170 ° C. When the processing temperature is lower than 70 ° C., the dimensional change during the process of the support 1 is large, and the variation between the wiring pitches tends to be large. Further, when the processing temperature exceeds 170 ° C., the support 1 is deformed, and the variation between the wiring pitches becomes large.

  The conductor paste is a mixture of conductor powder, organic binder, solvent, etc., and a dispersant or plasticizer may be added to adjust the dispersibility of the conductor particles and the hardness and strength of the conductor layer 2. Good. As a method for forming the conductor layer 2 on the support 1, for example, a screen printing method, a gravure printing method, an ink jet method, or the like, which is obtained by pasting a conductive material powder can be applied.

  Examples of the conductive material include one or more of W, Mo, Mn, Au, Ag, Cu, Pd (palladium), Pt (platinum), etc., and in the case of two or more, mixing, alloy, coating Or any other form. The conductor powder is manufactured by an atomization method, a reduction method, or the like, and may be subjected to treatments such as oxidation prevention and aggregation prevention as necessary. Moreover, fine powder or coarse powder may be removed by classification or the like to adjust the particle size distribution.

  As the organic binder, those conventionally used for conductive pastes can be used. For example, acrylic (acrylic acid, methacrylic acid or a homopolymer or copolymer thereof, specifically an acrylic ester. Copolymer, methacrylic acid ester copolymer, acrylic acid ester-methacrylic acid ester copolymer, etc.), polyvinyl butyral, polyvinyl alcohol, acrylic-styrene, polypropylene carbonate, cellulose, etc. Examples thereof include a polymer or a copolymer. In view of decomposition and volatility in the firing step, acrylic and alkyd organic binders are more preferable. The amount of the organic binder to be added varies depending on the conductor particles, but may be any amount that can disperse the conductor particles without any problem in the decomposability of the organic binder.

  The solvent is not particularly limited as long as the above-described conductor powder and organic binder can be well dispersed and mixed, and plasticizers such as terpineol, butyl carbitol acetate and phthalic acid can be used. Considering the drying property of the solvent after the formation of the layer 2, a low boiling point solvent such as terpineol is preferable.

  Next, as shown in FIG. 1B, a green sheet 3 is formed by ceramic slurry on a support 1 on which a conductor layer 2 is formed by a conductor paste, and the conductor-equipped green sheet comprising the conductor layer 2 and the green sheet 3 is formed. 4 is formed.

  The green sheet 3 used in this embodiment can be formed by molding a ceramic slurry mixed with ceramic powder, an organic binder, a solvent and the like on the support 1 on which the conductor layer 2 is formed. In order to adjust the dispersibility of the ceramic powder and the hardness and strength of the green sheet 3, a dispersant or a plasticizer may be added.

  At this time, it is important to set the difference between the solubility parameter of the ceramic slurry and the solubility parameter of the conductor layer 2 to 1.0 to 7.0.

  By setting the difference between the solubility parameter of the ceramic slurry and the solubility parameter of the conductor layer 2 to 1.0 to 7.0, the conductor paste 2 is printed on the support 1 and dried to form the conductor layer 2. When the green sheet 3 is formed, the green sheet 3 formed of the ceramic slurry and the conductor layer 2 formed by printing and drying the conductor paste are prevented from dissolving each other. Due to peeling of the conductive layer 2 from the green sheet when the green sheet on which the conductor is formed is peeled off from the support due to the conductive layer 2 repelling the ceramic slurry. The loss of the conductor layer 2 can be prevented.

  Here, the solubility parameter is quantified based on the property that organic components having similar properties are easily compatible with each other, and is also called an SP value. Since those having similar solubility parameter values are easily dissolved, they are used as an index indicating the dissolving power of the organic component.

  In this embodiment, the solubility parameter of the ceramic slurry was calculated from the solubility parameter of each organic component in the ceramic slurry and the volume fraction of each organic component. For example, if the ceramic slurry contains two organic components, the solubility parameters are 5 and 7, and the volume fraction is 70% and 30%, respectively, the solubility parameter of the ceramic slurry is 5 × 0.7 + 7 ×. 0.3 = 5.6. As the solubility parameter of the organic component of the present invention, solubility parameter data published by Kodansha “Solvent Handbook” (Shozo Asahara et al., 1976, first edition) was used.

The solubility parameter of the ceramic slurry or conductor paste can be changed depending on the type of organic component added to the ceramic slurry or conductor paste or the addition ratio when a plurality of types are added. In particular, in the case of a conductor paste, it is preferable to change the solubility parameter by adding a plurality of types of solvents, which are organic components to be added, and changing the solvent ratio by drying or the like after forming the conductor layer 2. Thus, a solvent that easily forms a conductor is selected and added to the support, and after the formation of the conductor layer 2 and before the ceramic slurry is applied, the drying conditions such as temperature and time after the formation of the conductor layer 2 are adjusted. This makes it easy to change the solubility parameter to a desired range.

  The green sheet 3 can be formed by forming a ceramic slurry mixed with ceramic powder, an organic binder, a solvent, and the like on the support using the support 1 on which the conductor layer 2 is formed as the support. It is. In order to adjust the dispersibility of the ceramic powder and the hardness and strength of the green sheet 3, a dispersant or a plasticizer may be added. The green sheet 3 can also be formed of a first green sheet layer and a second green sheet layer containing a molten component.

  In this case, the method of forming the second green sheet layer on the first green sheet layer is different from (1) the first green sheet layer on the support on which the conductor layer 2 is formed. A method of laminating the second green sheet layer formed on the support of the first layer on the first green sheet layer, and (2) forming on the support on which the conductor layer 2 is formed. A method of forming a slurry of the second green sheet on the formed first green sheet layer, and (3) the first green applied on the support on which the conductor layer 2 is formed. The method of apply | coating and forming the slurry of the said 2nd green sheet layer on the slurry of a sheet layer is mentioned.

Among these, for the methods (2) and (3), since the first green sheet layer and the second green sheet layer can be simultaneously formed, the construction period is increased by increasing the number of steps and the number of layers. It is possible to form a high fluidity layer without causing problems such as a long period of time, an increase in cost, a decrease in yield, and a decrease in reliability of conductor connection between layers. Further, since there is no lamination step of the high fluidity layer, there is no air entrainment when the high fluidity layer is laminated, and the conductor layer is a laminated green sheet (the first green sheet layer and the second green sheet layer). Since the laminated green sheet is flat without a step in the conductor layer, it is possible to obtain a highly reliable ceramic electronic component without delamination.

  In the method (1), the first green sheet layer and the second green sheet layer are separately formed, laminated and heated to heat the conductor layer 2 and the first and second green sheets. Since the laminated green sheet composed of the sheet layers is produced, green sheets or ceramic slurries having a wider solubility parameter can be used without being mixed and made identical when forming the green sheet 3.

  Among the above-mentioned melting components, those having a melting point of 35 to 100 ° C. are preferable. This is because when the material having a melting point in this range is used, the second green sheet layer is not softened and deformed at room temperature, so that the handling up to the lamination process is facilitated, and the ceramic laminate 5 is produced. This is because organic components such as the organic binder and plasticizer in the ceramic laminate 5 are hardly decomposed during heating in the process, and therefore, delamination caused by the decomposition gas is effectively prevented. Examples of the melting component having a melting point of 35 to 100 ° C. include hexadecanol, polyethylene glycol, polyglycerol, stearylamide, oleylamide, ethylene glycol monostearate, paraffin, stearic acid, and silicone.

  The content of the molten component contained in the second green sheet layer varies depending on the organic binder component to be used and its amount, and the molten component to be used, but the second green sheet layer is in a state where the molten component is melted. May be softened so that the first green sheet layer of the laminated green sheet positioned below and the conductor layer 2 embedded therein are contacted without gaps.

Examples of the ceramic powder used for the ceramic slurry include Al ₂ O ₃ , AlN, glass ceramic powder (a mixture of glass powder and filler powder) and the like for a ceramic wiring board, and BaTiO ₃ for a multilayer capacitor. Composite perovskite ceramic powders such as PbTiO ₃ and PbTiO _{3, and the} like, which are appropriately selected according to the characteristics required for ceramic electronic components.

Examples of the glass component of the glass ceramic powder include SiO ₂ —B ₂ O ₃ and SiO _2.
-B ₂ O ₃ -Al ₂ O _{3 based, SiO 2 -B 2 O 3 -Al} 2 O 3 -MO -based (where, M represents Ca, Sr, Mg, Ba, or _Zn), SiO ₂ -Al 2 O ₃ —M ¹ O—M ² O system (where M ¹ and M ² are the same or different and represent Ca, Sr, Mg, Ba or Zn), SiO ₂ —B ₂ O ₃ —Al ₂ O ₃ — M ¹ O—M ² O system (where M ¹ and M ² are the same as above), SiO ₂ —B ₂ O ₃ —M ³ ₂ O system (where M ³ represents Li, Na or K) ), SiO ₂ —B ₂ O ₃ —Al ₂ O ₃ —M ³ ₂ O (wherein M ³ is the same as above), Pb glass, Bi glass and the like.

Further, as the filler powder of the glass ceramic powder, for example, a composite oxide of Al ₂ O ₃ , SiO ₂ , ZrO ₂ and an alkaline earth metal oxide, a composite oxide of TiO ₂ and an alkaline earth metal oxide, A ceramic powder such as a composite oxide (for example, spinel, mullite, cordierite) containing at least one selected from Al ₂ O ₃ and SiO ₂ can be used.

  As the organic binder, those conventionally used for green sheets can be used. For example, acrylic (acrylic acid, methacrylic acid or a homopolymer or copolymer of an ester thereof, specifically an acrylic ester. Copolymer, methacrylic acid ester copolymer, acrylic acid ester-methacrylic acid ester copolymer, etc.), polyvinyl butyral, polyvinyl alcohol, acrylic-styrene, polypropylene carbonate, cellulose, etc. Examples thereof include a polymer or a copolymer. In view of decomposition and volatility in the firing step, an acrylic binder is more preferable.

  Moreover, as for the particle size of said ceramic powder or glass ceramic powder (mixture of glass powder and filler powder), it is desirable that the 90% particle size (D90) in the number cumulative particle size distribution is 10 μm or less.

  This is because when the ceramic powder contained in the ceramic green sheet 3 is discharged so as to be physically ejected from the inside of the through hole by the jet gas of the support body 1 volatilized by the third harmonic YAG laser, The size of the separation mark generated on the side surface of the through hole is reduced, and the uneven shape on the side surface of the through hole is made flat, so that when the conductor paste is filled in the through hole, it is filled with the through hole. This is because a void is not generated between the conductor pastes and a ceramic electronic component having high conduction reliability is obtained.

  When the ceramic green sheet 4 with a conductor layer is subjected to a through hole processing by irradiation with a third harmonic YAG laser and the support 1 contains a UV absorber, the ceramic green sheet 3 is penetrated. As the process of forming the holes, first, the ceramic green sheet 3 is irradiated with the third harmonic YAG laser light. Since the UV light absorption rate of the ceramic green sheet 3 is as low as about 20 to 30%, The effect of drilling the ceramic powder in the through hole by the harmonic YAG laser is insufficient, and the portion of the ceramic green sheet 3 irradiated with the third harmonic YAG laser (the portion that becomes the through hole) There is a possibility that the ceramic powder of the raw material remains and the so-called glass remains, and a desired through hole cannot be obtained.

  However, the UV light that has not been absorbed by the ceramic green sheet 3 passes through the ceramic green sheet 3 and is irradiated onto the support 1. Here, if a UV absorber is contained in the support 1, the support 1 is volatilized by the UV light transmitted through the ceramic green sheet 3 and gas is ejected.

  After that, the ceramic powder contained in the ceramic green sheet 3 is caused by the gas that the support 1 volatilizes and ejects the portion that becomes the through-hole irradiated with the third harmonic YAG laser on the surface side of the ceramic green sheet 3. From the support body 1 side, it ejects so that it may be physically ejected in the surface direction of the ceramic green sheet 3, and is discharged | emitted, and a through-hole is formed.

  At this time, if the particle size of the ceramic powder contained in the ceramic green sheet 3 is 90 μm or less in the number cumulative particle size distribution (D90) is 10 μm or less, the inorganic powder is discharged so as to be ejected by the jet gas. It can be suppressed that the uneven shape (detachment trace) on the side surface of the through hole after the formation of the conductive paste in the through hole becomes a gap between the two and decreases the conduction reliability. Moreover, when a space | gap arises in the inside of a through-hole and a conductor paste, generation | occurrence | production of a crack can be reduced by making the space | gap part a starting point by the stress by the expansion | swelling or shrinkage | contraction of the air in a space | gap part in a baking process.

  In addition, if the 90% particle size (D90) in the number cumulative particle size distribution is 10 μm or less as the particle size of the ceramic powder contained in the ceramic green sheet 3, the separation trace becomes a gap between the through hole and the conductor paste. However, when the 10% particle size (D10) in the number cumulative particle size distribution is less than 0.1 μm, for example, when producing a ceramic electronic component, a ceramic powder, an organic binder, a solvent, etc. are mixed. In the step of preparing the ceramic slurry, the ceramic powder is agglomerated, and when the green sheet 3 is formed by coating the ceramic slurry on the support 1 on which the conductor layer 2 is formed with the conductor paste, Protrusions due to aggregated particles are generated on the surface, and voids are generated around the aggregated particles due to air intake during coating. . Therefore, as for the particle size of the ceramic powder contained in the ceramic green sheet 3, the 10% particle size (D10) in the number cumulative particle size distribution is more preferably 0.1 μm or more.

  The solvent is not particularly limited as long as the ceramic powder and the organic binder can be well dispersed and mixed, and examples thereof include organic solvents such as toluene, ketones, alcohols, and water. Among these, solvents having a high evaporation coefficient such as toluene, methyl ethyl ketone, and isopropyl alcohol are preferable because the drying process after slurry application can be performed in a short time, so that the conductor is hardly dissolved.

  Examples of the method for forming the green sheet 3 by applying the ceramic slurry include a conventionally known doctor blade method, lip coater method, die coater method and the like. In particular, when an extrusion method such as a die coater method, a slot coater method, or a curtain coater method is used, since these are non-contact coating methods, the green sheet 3 is not mixed with the conductor layer 2 by physical force. It is good because it can be formed. The coating conditions at that time may be any coating speed such that when the slurry is applied, the conductor formed on the support does not melt or peel, and the slurry flows without gaps between the conductors. About 5 m / min is sufficient. Further, the green sheet 3 is formed so as to be thicker than the conductor layer 2.

Next, a through-hole conductor for connecting the conductor layers 2 between the upper and lower layers is formed. This through-hole conductor is formed by a means such as embedding a conductive paste obtained by pasting a conductive material powder into a through hole formed in the green sheet 4 with a conductor by YAG laser processing by printing or press filling. Machining of the through hole, drilling by laser according to the mold and CO _2, since the diameter 50μm is processed on or optically limits of the mold pin, be processed by a YAG laser third harmonic 355nm preferable. With a YAG laser having the first harmonic of 1064 nm or the second harmonic of 532 nm, it is difficult to optically process a minute hole of 50 μm or less. In addition, when the fourth harmonic 266 nm has insufficient power for drilling through the ceramic green sheet, the number of shots of the laser is remarkably increased and the productivity is extremely deteriorated. At the same time, the conductive green sheet 4 is thick. Therefore, the difference in through-hole diameter between the front and back sides of the conductor-equipped green sheet 4 is extremely large.

  Further, when processing with a third harmonic YAG laser, the processing point energy is more preferably 0.8 to 3.0 W. This is because when the processing point energy is less than 0.8 W, the number of shots is remarkably increased and the productivity is extremely deteriorated, and when the conductor-equipped green sheet 4 is thick, the difference in through-hole diameter between the front and back sides of the conductor-equipped green sheet 4 This is because extremely large holes are processed. Further, when the processing point energy is larger than 3.0 W, the support 1 is volatilized, the impact of the gas explosively ejected is large, the periphery of the through hole is greatly damaged by the impact, and the through hole has a desired surface. This is because the appearance is remarkably impaired at the same time as the diameter becomes larger.

  Further, when the through hole is processed, it is more preferable that the green sheet 3 is held on the support 1 because deformation of the green sheet 4 with a conductor can be prevented.

  Furthermore, when processing the through-hole, it is more preferable that the green sheet 3 is held on the support 1 and the support 1 is disposed on the laser emission side. The ceramic green sheet 3 is irradiated with the third harmonic YAG laser light that has not been absorbed by the ceramic green sheet 3 and passes through the ceramic green sheet 3 and is irradiated onto the support 1 containing the UV absorber. This is because the ceramic powder constituting the ceramic green sheet 3 is exhausted so that the support 1 is volatilized and explosively ejected, and the through holes are formed by the action of being ejected so as to be physically ejected.

  Furthermore, it is preferable that the support 1 contains a UV absorber. If the support 1 does not include a UV absorber, when the through hole is formed in the conductor-equipped green sheet 4, no hole is formed at the same time, and it becomes extremely difficult to fill the through hole with the conductive paste. .

  Examples of the UV absorbing material in the support 1 include Ti, Ce, C, and the like. For example, 5 to 15% is preferably contained. This is because if the content of the UV absorbing material is less than 5%, the effect of UV absorption is difficult to obtain, and if it exceeds 15%, the sheet becomes hard and processing becomes difficult.

Further, the UV absorber contained in the support 1 uses a colorless organic UV absorber, and the conductor layer 2 formed on the conductor-equipped green sheet 4 can be visually recognized through the support 1. More preferred. This is because, in the process of forming the green sheet 4 with a conductor, a conductor paste is applied to the support 1 to form a conductor layer 2, and a ceramic slurry is applied to the support 1 on which the conductor layer 2 is formed. to form the green sheet 3, the case of using a colored UV absorbers such as metal oxides or organic pigments to the support 1, at the time of drilling a through hole in the conductive layer provided with a ceramic green sheet 4 This is because the position where the through hole is to be formed cannot be recognized.

  Next, as shown in FIG.1 (c), the green sheet 4 with a conductor is peeled off from the support body 1, the green sheets 4 with a conductor are aligned and stacked, and it heat-presses and press-fits, and is a ceramic laminated body. 5 is produced. In addition, when peeling a support body, it is also possible to perform processes, such as a heating, as needed. Moreover, although the conditions of the heat-pressing in the case of crimping | bonding differ with kinds and quantity of organic binders etc. to be used, they are 30-100 degreeC and 2-20 MPa in general. At this time, in order to improve the adhesiveness between the conductor-attached green sheets 4, it is also possible to use an adhesive in which a solvent is mixed with an organic binder, a plasticizer, or the like.

  With respect to the green sheets 4 with conductors that are aligned and stacked, an appropriate pressure (appropriate pressure) is applied so that the laminated green sheets 4 with conductors are not displaced and the green sheets 4 with conductors can be reliably stacked ( When 0.1 to 1 MPa is performed, more accurate and reliable crimping can be performed.

In the process of producing the ceramic laminate 5, the conductor-equipped green sheets 4 are brought into close contact with each other without generating voids around the conductor layer 2 or between the conductor layers 2. Ceramic electronic parts obtained by firing are free from delamination.

Conductor with the green sheet 4, it is not name that greatly deformed under pressure to the extent that pressing in order to ensure the lamination. Therefore, the shape of the green sheet with conductor 4 and the conductor layer 2 formed thereon is not deformed, and further, there is no distortion to the green sheet with conductor 4 due to pressurization, and the obtained ceramic laminate 5, and The ceramic electronic component obtained by firing the has a high dimensional accuracy.

For example, when a green sheet in which the conductor layer 2 is formed on the green sheet 3 is used, the dimensional accuracy of the ceramic laminate 5 and the ceramic electronic component is about ± 0.5% (dimensional error). When the conductor-equipped green sheet 4 in which the conductor layer 2 and the green sheet are formed on the support 1 is used, the dimensional accuracy of the ceramic laminate 5 and the ceramic electronic component is ± 0.2% or less, and the dimensional accuracy is greatly improved. It was confirmed by experiment.

  In addition, when manufacturing a ceramic electronic component having a cavity, it is not necessary to press the green sheet with a large pressure, so that the warping of the bottom of the cavity due to the difference in the elongation of the green sheet due to the pressurization between the cavity periphery and the cavity bottom. It is possible to suppress the generation, and it is possible to obtain a ceramic electronic component that can accurately and reliably mount the electronic element on the bottom of the cavity.

  Finally, by firing the ceramic laminate 5, a ceramic electronic component as a product is completed. The firing step consists of removing organic components and sintering the ceramic powder. Removal of the organic component is performed by heating the ceramic laminate 5 in a temperature range of 100 to 800 ° C. to decompose and volatilize the organic component. The sintering temperature varies depending on the ceramic composition, and is performed within a range of about 800 to 1600 ° C. The firing atmosphere varies depending on the ceramic powder and the conductor material, and is performed in the air, in a reducing atmosphere, in a non-oxidizing atmosphere or the like, and may contain water vapor or the like in order to effectively remove organic components.

  The ceramic electronic component after firing has a good connection to the exposed surface of the conductor layer 2, to prevent corrosion of the conductor layer 2, or to an external substrate or other electronic component using solder, metal wire, or the like. Therefore, Ni or Au plating may be applied.

When a low-temperature sintered material such as glass ceramics is used as the ceramic material, if a constrained green sheet is further laminated on the upper and lower surfaces of the ceramic laminate 5 and fired, and the restrained sheet is removed after firing, the dimensions are higher. An accurate ceramic electronic component (ceramic substrate) can be obtained. The constrained green sheet is a green sheet mainly composed of a hardly sinterable inorganic material such as Al ₂ O ₃ and does not shrink during firing. In the laminate in which the constraining green sheets are laminated, the constraining green sheet that does not shrink is prevented from shrinking in the laminating plane direction (xy plane direction) and shrinks only in the laminating direction (z direction). Is suppressed.

  In addition to the hardly sinterable inorganic component, the constrained green sheet may contain a glass component having a softening point equal to or lower than the firing temperature, for example, the same glass as the glass in the green sheet 3. When the glass is softened and bonded to the green sheet 3 during firing, the bond between the green sheet 3 and the constraining green sheet becomes strong, and a more reliable restraining force can be obtained. The amount of the glass at this time may be 0.5 to 15% by mass by external addition to the inorganic component that is a combination of the hardly sinterable inorganic component and the glass component. The firing shrinkage can be suppressed to, for example, 0.5% or less.

  The restraining sheet is removed after firing. Examples of the removal method include conventionally known polishing, water jet, chemical blasting, sand blasting, wet blasting (a method of spraying abrasive grains and water by air pressure), dry ice blasting (abrasive grains are dry ice), and the like. .

  Ceramic electronic parts manufactured through the above-mentioned processes have almost no delamination, high dimensional accuracy, high-precision conductors, and excellent electrical characteristics and airtightness. It becomes.

  Examples of the present invention will be described in detail below.

  First, alumina powder and organic components as shown in Table 1 are mixed to prepare a ceramic slurry, and on the PET film support 1 on which the conductor layer 2 is formed by printing and drying the conductor paste in the same manner as described above. A ceramic slurry with a thickness of 50 μm was applied by a lip coater method and dried to prepare a ceramic green sheet 4 with a conductor.

  As a procedure for producing the ceramic green sheet 4 with a conductor, first, an organic binder and a solvent shown in Table 1 were added to Cu powder and mixed using three rolls to produce a conductor paste. The conductor paste was adjusted to 10000 cps by adding a solvent as appropriate. Thereafter, a conductive paste having a width and a gap of 75 μm was formed on the support 1 by applying a conductive paste by screen printing.

Next, the organic binder and solvent shown in Table 1 were added to the inorganic powder of SiO ₂ —B ₂ O ₃ —Al ₂ O ₃ glass powder 60% by mass and alumina powder 40% by mass, and 24 hours in a ball mill. A ceramic slurry was prepared by mixing.

  A ceramic slurry was applied on the support 1 on which the conductor layer 2 was formed, and dried with a hot air drier to obtain a ceramic green sheet 4 with a conductor layer.

  The ceramic green sheet 4 with a conductor was peeled off from the support body 1, and the state of bleeding and peeling was evaluated by observing the conductor portion on the peeled surface with a binocular microscope. The results are shown in Table 1.

Observation with a binocular microscope was 20 times.

  In Table 1, “◯” in the “Brightness / peeling of conductor” column indicates that the conductor was excellent without any blurring or peeling. On the other hand, “Δ” indicates that blurring or peeling is observed in a part of the conductor.

  In Table 1, Examples 2, 4, and 6, which are examples of the present invention, were excellent without any blurring or peeling of the conductor. On the other hand, in Examples 1, 3, 5 and 7, the conductor was melted or peeled off.

  As described above, if the difference between the solubility parameter of the ceramic slurry and the solubility parameter of the conductor layer obtained by drying the conductor paste is 1.0 to 7.0, the ceramic slurry and the conductor are dissolved to prevent the conductor from blurring. When the ceramic green sheet 4 on which the conductor is formed is peeled off from the support 1, it is possible to prevent the conductor from peeling off from the ceramic green sheet.

Next, a polymer of isobutyl methacrylate as the organic binder shown in Table 1 is added to the Cu powder in a volume fraction of 30%, and dibutyl phthalate as a solvent is added in a volume fraction of 70% and mixed using three rolls. Thus, a conductor paste was prepared. The conductor paste was adjusted to 10000 cps by appropriately adding a dibutyl phthalate solvent. Thereafter, a conductive paste having a width and a gap of 75 μm was formed on the support 1 by applying a conductive paste by screen printing.

Next, an acrylic acid ester-methacrylic acid ester copolymer as an organic binder in a volume fraction of SiO ₂ —B ₂ O ₃ —Al ₂ O ₃ based glass powder 60 mass% and alumina powder 40 mass%. 40% and 60% of ethyl alcohol as a solvent was added as a solvent, and mixed with a bead mill manufactured by Mitsui Mining Co., to prepare a ceramic slurry. At this time, the 90% particle size (D90) particle size in the number cumulative particle size distribution of the ceramic powder contained in the ceramic green sheet 3 was adjusted by the mixing time in the bead mill so that the particle size shown in Table 2 was obtained.

  A ceramic slurry was applied to a thickness of 50 μm by the lip coater method on the support 1 on which the conductor layer 2 was formed, and dried by a hot air dryer to obtain a ceramic green sheet 4 with a conductor layer.

The ceramic green sheet 4 with the conductor is irradiated with a third harmonic YAG laser (UV-YAG laser) manufactured by Hitachi Via Mechanics with the ceramic green sheet 3 being irradiated with the laser beam while being supported by the support 1. Then, a through hole with a diameter of 30 μm was processed. Thereafter, through-hole conductors are formed by filling the through-holes with screen printing to form through-hole conductors, the support 1 is peeled off, and firing is performed. The measurement was carried out with a 20 × binocular microscope. Table 2 shows the results of observing defects between the through hole and the conductor.

  In Table 2, “◯” in the defect column indicates that there was no defect and it was excellent. On the other hand, “x” indicates that a defect has been confirmed.

  In Table 2, in Examples 1, 2, 3, 4, 5, 6, 7, and 8, which are examples of the present invention, no defect is observed between the through hole and the conductor from the cross-sectional observation, and surface observation is performed. From the above, no defects were found in the through hole. On the other hand, in Examples 9, 10, 11, and 12, a defect was confirmed between the through hole and the conductor from cross-sectional observation.

  Further, from the surface observation, in Examples 9, 10, 11, and 12, cracks generated from the through hole toward the substrate were recognized. In the longest crack length column of Table 2, “◯” indicates that no crack was generated, and “Δ” indicates that the crack has a length of 15 μm or less and does not affect the conduction reliability. , “X” indicates that a crack having a size affecting the conduction reliability occurred. Here, the longest crack length in Example 9 is “Δ”, which indicates that the crack is a minute crack that does not affect the conduction reliability, but it is determined to be defective because it may induce a crack in the substrate. did.

  As described above, when the 90% particle size (D90) in the number cumulative particle size distribution of the ceramic powder contained in the ceramic green sheet 3 is 10 μm or less, the uneven shape on the side surface of the through hole is made flatter. Therefore, when the conductor paste is filled in the through hole, no gap is generated between the through hole and the filled conductor paste, and a ceramic electronic component having high conduction reliability can be obtained.

(A)-(d) is sectional drawing for every process which shows an example of embodiment of the manufacturing method of the ceramic electronic component of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Support body 2 ... Conductor layer 3 ... Ceramic green sheet 4 ... Ceramic green sheet 5 with a conductor layer ... Ceramic laminate

Claims (7)

A step A of forming a conductor layer by applying a conductor paste on a support;
Step B for obtaining a ceramic green sheet with a conductor layer by applying a ceramic slurry on the support on which the conductor layer has been formed to form a ceramic green sheet layer and drying;
Forming a through hole in the ceramic green sheet with a conductor layer and filling the through hole with a conductive paste; and
Step D of forming a ceramic laminate by laminating a plurality of ceramic green sheets with conductor layers while heating,
In a method for manufacturing a ceramic electronic component, comprising the step E of firing the ceramic laminate.
The difference between the solubility parameter of the ceramic slurry solubility parameter and the conductor layer is 1.0 to 7.0, wherein the support is prepared by heat treatment of 70 to 170 ° C., plane before and after the time of the drying A method for manufacturing a ceramic electronic component, wherein a dimensional change rate in a direction is within 0.1%.   2. The method of manufacturing a ceramic electronic component according to claim 1, wherein the support includes a UV absorber, and the through hole is formed by irradiation with a YAG laser in the step C. 3.   3. The step B includes a step of forming a second ceramic green sheet layer containing a melting component that is melted by heating in the step D on the ceramic green sheet layer. The manufacturing method of the ceramic electronic component of description.   The second ceramic green sheet layer is formed by applying and drying the second ceramic slurry on the ceramic slurry applied in the step A, and the solubility parameter of the ceramic slurry and the second ceramic slurry. The method of manufacturing a ceramic electronic component according to claim 3, wherein the difference in solubility parameter of the ceramic electronic component is 2 or more.   In the step B, the second ceramic green sheet layer is formed by laminating and heating the ceramic green sheet layer, and the molten component becomes a molten state by heating in the step B and the step D. The method of manufacturing a ceramic electronic component according to claim 4.   6. The method of manufacturing a ceramic electronic component according to claim 3, wherein the melting component has a melting point in a range of 35 to 100.degree.   3. The YAG laser according to claim 2, wherein the YAG laser is a third harmonic YAG laser, and a 90% particle size (D90) in a number cumulative particle size distribution of the ceramic powder contained in the ceramic green sheet is 10 μm or less. The manufacturing method of the ceramic electronic component of description.

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