JP2005277167A - Method for manufacturing electronic component - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing an electronic component wherein delamination is eliminated and high dimensional accuracy is installed. <P>SOLUTION: The method for manufacturing an electronic component is provided with a process for forming a first ceramic green sheet layer 2 on a support 1, a process wherein a second ceramic green sheet layer 3 is formed on the first ceramic green sheet layer 2 and a ceramic green sheet 4 is formed, a process for forming a conductor layer 5 on the second ceramic green sheet layer 3 of the ceramic green sheet 4, a process wherein a plurality of the ceramic green sheets 4 on which the conductor layers 5 were formed are laminated and heated, and a ceramic green sheet lamination 6 is formed, and a process for baking the ceramic green sheet lamination 6. Furthermore, the first ceramic green sheet layer 2 contains melting component which will be in melting status at the time of heating when the ceramic green sheet lamination 6 is formed. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for manufacturing an electronic component such as a multilayer capacitor or a multilayer ceramic wiring board.

  In recent years, with the miniaturization of electronic devices, there has been a demand for miniaturization and high performance in electronic components such as multilayer capacitors and multilayer ceramic wiring boards. For example, multilayer capacitors are required to have multilayered thin dielectric layers and conductor layers for miniaturization and high capacity. In addition, in a multilayer ceramic wiring board, a thinner insulating layer and a wiring conductor layer are formed in multiple layers in order to reduce the size and increase the density of the wiring conductor, and the wiring conductor layers are required to have finer widths and intervals. .

  Such electronic parts are made by adding an organic binder, plasticizer, solvent, etc. to ceramic powder to form a slurry, forming a ceramic green sheet (hereinafter also referred to as green sheet) with a doctor blade, etc., and then a conductor containing metal powder. A conductive layer is formed on the green sheet by printing a paste, etc., and then a green sheet on which a plurality of conductive layers are formed is laminated and pressed to obtain a laminated body. Can be obtained by firing.

  When a large number of green sheets on which conductor layers are formed are stacked in response to demands for electronic components, the difference in thickness between a portion where the conductor layers are formed overlaps with a portion where the regions do not overlap. For this reason, when the laminated green sheets are pressed in the thickness direction, the applied pressure is sufficiently applied in the portion where the regions where the conductor layers are formed overlap, but the applied pressure is not easily applied in the other portions. It tends to be insufficient crimping. As a result, when such a laminate is fired, there is a problem in that delamination (delamination) occurs at a portion where the pressure bonding is insufficient.

  When such delamination is present inside the electronic component, there is a problem in that the electrical characteristics cannot be secured because the capacitance value is likely to change or the dielectric breakdown is likely to occur.

  In order to solve this problem, Patent Document 1 proposes to use a laminate having a highly fluid portion having high fluidity when pressurized. When the laminated body is pressed in the thickness direction, the high fluidity part existing in the area where the internal electrodes are laminated moves to the remaining part and the thickness of the remaining part increases to increase the pressure. Is uniformly added to the whole, so that delamination hardly occurs.

  In addition, when another green sheet is laminated on the conductor layer formed on the green sheet, the green sheet hardly follows the cross-sectional shape of the conductor layer, so that a void is generated around the conductor layer. There is a problem that delamination is likely to occur. In particular, when the distance between the conductor layers was fine, voids were easily generated between the conductor layers.

In order to solve this problem, Patent Document 2 proposes that after a conductor layer is formed on a green sheet, a ceramic paste is printed in a region around the portion where the conductor layer is formed. If such a method is used, the step between the conductor layer and the green sheet can be eliminated by printing the ceramic paste in a region around the portion where the conductor layer is formed. For this reason, it is possible to suppress the generation of voids around the conductor layer and between the wiring conductor layers, and to suppress the occurrence of delamination caused by the voids. In addition, there is no difference in thickness even when a plurality of green sheets on which a conductor layer is formed are laminated, so that pressure can be applied without unevenness and crimping can be suppressed, and the occurrence of insufficient crimping can be suppressed. Generation of lamination can be suppressed.
Japanese Patent No. 3344100 Japanese Patent Laid-Open No. 5-217448

  However, in the conventional method using a laminate having a high fluidity portion, a high pressure of 180 MPa, for example, is applied in the thickness direction in order to move the high fluidity portion and perform pressure bonding so that delamination does not occur. There is a need. When such a high pressure is applied to the green sheet on which the conductor layer is formed, the shape of the green sheet or the conductor pattern is deformed. As a result, it is difficult to mount components on the board because the desired dimensional accuracy of the board cannot be obtained, and the conductor pattern shape as designed cannot be obtained. There is a problem that electrical characteristics such as the above cannot be obtained. Furthermore, the problem of the gap generated between the wiring conductor layers when the spacing between the wiring conductor layers is fine remains unsolved.

  In addition, in the method of printing the ceramic paste on the area around the portion where the conductor layer is formed, not only is the process of printing the ceramic paste further on the green sheet on which the conductor layer is formed, but also the wiring conductor When the distance between the layers is fine, it is difficult to print the ceramic paste between the wiring conductor layers. For this reason, the ceramic paste is also printed on the wiring conductor layer. The ceramic paste printed on the wiring conductor layer causes the through conductor to connect the wiring conductor layers that are stacked and disposed above and below the wiring conductor. There was a problem that it was not connected to the layer.

  Furthermore, when manufacturing an electronic component having a cavity, a green sheet with a through hole serving as a cavity and a green sheet without a through hole serving as a bottom of the cavity are laminated and pressed. There was a problem that the cavity bottom of the sheet laminate was warped. This is because pressure is applied only to the periphery of the cavity due to pressurization for crimping, and the lean sheet around the cavity extends due to pressurization, while no pressure is applied to the bottom of the cavity, so the green sheet at the bottom of the cavity It is because it is pushed from. This is more likely to occur when the electronic component is smaller and the cavity bottom is thinner. If the cavity bottom warps, it becomes difficult to mount an electronic element such as a crystal resonator or an IC chip. Even if it can be mounted, the mounted components are tilted. Therefore, when an optical semiconductor element such as a CCD or C-MOS is mounted, there is a problem that the light receiving accuracy deteriorates.

  The present invention has been completed in view of the above-described conventional problems, and an object of the present invention is to provide a method for manufacturing an electronic component that has no delamination and has high dimensional accuracy.

  The method of manufacturing an electronic component according to the present invention includes a step of forming a first ceramic green sheet layer on a support, and a second ceramic green sheet layer on the first ceramic green sheet layer to form a ceramic green. A step of forming a sheet, a step of forming a conductor layer on the second ceramic green sheet layer of the ceramic green sheet, and heating a plurality of the ceramic green sheets on which the conductor layer is formed. A step of producing a ceramic green sheet laminate, and a step of firing the ceramic green sheet laminate, wherein the first ceramic green sheet layer is used for producing the ceramic green sheet laminate. It contains a molten component that becomes a molten state when heated.

  The electronic component manufacturing method of the present invention is preferably characterized in that the melting component has a melting point of 35 to 100 ° C.

  In the method of manufacturing an electronic component according to the present invention, the thickness of the first ceramic green sheet layer is preferably 10 to 200 μm.

  The electronic component manufacturing method of the present invention is preferably characterized in that the tensile properties of the second ceramic green sheet layer are a yield point strength of 0.5 MPa or more and a yield point elongation of 50% or less.

  In the electronic component manufacturing method of the present invention, preferably, the yield point elongation of the first ceramic green sheet layer is 50% or less.

  The method for producing an electronic component of the present invention preferably includes a step of forming a through hole by punching in the ceramic green sheet, and the yield point elongation of the ceramic green sheet layer on the punching start surface side is 50% or less, The yield point elongation of the ceramic green sheet layer on the punching finish side is 20% to 50%.

In the electronic component manufacturing method of the present invention, the second ceramic green sheet layer preferably has a Cobb size of 50 to 500 g / m ² .

  According to the method for manufacturing an electronic component of the present invention, since the first ceramic green sheet layer contains a melting component that melts when heated, the first ceramic green sheet layer is heated when the ceramic green sheets on which the conductor layer is formed are laminated and heated. Since the first ceramic green sheet layer is softened, the first ceramic green sheet layer follows the shape of the second ceramic green sheet layer of the ceramic green sheet located below and the conductor pattern formed thereon. It will be deformed. As a result, the ceramic green sheets adhere to each other without generating voids around the conductor layer or between the conductor layers, and the electronic component obtained by firing the ceramic green sheet laminate is free from delamination.

  In addition, since the first ceramic green sheet layer contains a melting component that melts when heated, the first ceramic green sheet layer is softened and has adhesiveness only by heating. There is no need to crimp ceramic green sheets. And since the 2nd ceramic green sheet layer in which a conductor pattern is formed does not contain the fusion | melting component which fuse | melts at the time of a heating, a 2nd ceramic green sheet layer does not deform | transform at the time of a heating, The laminated | stacked ceramic green sheet has The degree to which the softened first ceramic green sheet layer is pressed in order to assist in deforming the second ceramic green sheet layer and the shape of the conductor pattern formed thereon, so as not to be displaced. Then, it does not deform. Therefore, the ceramic green sheet and the shape of the conductor pattern formed thereon are not deformed, and the obtained ceramic green sheet laminate and the electronic component obtained by firing it have high dimensional accuracy.

  In addition, when the melting point of the melting component that melts when heated is 35 ° C. to 100 ° C., the first ceramic green sheet layer does not soften and deform at room temperature. The organic components such as the binder and the plasticizer in the ceramic green sheet are not decomposed during heating, so that delamination does not occur due to the decomposition gas, which is more preferable.

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

  In addition, if the thickness of the first ceramic green sheet layer is 10 to 200 μm, the first ceramic green sheet layer is the second ceramic green sheet layer of another ceramic green sheet positioned under the first ceramic green sheet layer and the It can be deformed following the shape of the conductor pattern formed thereon, and deformation during lamination can be suppressed.

  In addition, if the tensile strength of the second green sheet layer is a yield point strength of 0.5 MPa or more, the first ceramic green sheet layer softened during heating can be held by the second ceramic green sheet layer 3 without cracks or defects. If the yield point elongation is 50% or less, even if the first ceramic green sheet layer 2 is softened, the ceramic green sheet 4 can maintain a highly accurate dimension without being deformed during lamination.

  Further, if the yield point elongation of the first ceramic green sheet layer is 50% or less, the first ceramic green sheet layer is not easily deformed even if through holes are formed in the ceramic green sheet by punching. The deformation of the through-holes can be suppressed.

  When the ceramic green sheet includes a step of forming a through hole by punching, the yield point elongation of the ceramic green sheet layer on the punching start surface side is 50% or less, and the ceramic green sheet layer on the punching end surface side If the yield point elongation is 20% to 50%, deformation of the through hole, generation of burrs on the punching start surface and generation of cracks around the through hole on the punching end surface can be suppressed.

When the second ceramic green sheet layer has a cobb size of 50 to 500 g / m ² , the conductor layer is formed by printing a conductor paste on the second ceramic green sheet layer of the ceramic green sheet. In addition, since the absorption of the solvent in the printed conductor paste into the second ceramic green sheet layer becomes appropriate, the conductor layer is formed without causing defects in the conductor layer such as bleeding, drying defects, blurring, and defects. Is possible. Further, it is possible to prevent the temperature at which the first ceramic green sheet layer is softened from being lowered by the solvent in the conductor paste passing through the second ceramic green sheet layer and penetrating into the first ceramic green sheet layer. it can.

  As described above, according to the manufacturing method of the present invention, it is possible to obtain a ceramic green sheet laminate in which no gap is generated between the ceramic green sheets and the deformation of the ceramic green sheet or the conductor layer is suppressed. The electronic component produced by the manufacturing method of the invention has no delamination and becomes an electronic component having high dimensional accuracy.

  The method for manufacturing an electronic component of the present invention will be described in detail below.

  FIG. 1 is a sectional view for each process showing an example of an embodiment of an electronic component manufacturing method according to the present invention, wherein 1 is a support, 2 is a first ceramic green sheet layer, and 3 is a second ceramic green sheet. Layers 4, 4 are ceramic green sheets, 5 is a conductor layer, and 6 is a ceramic green sheet laminate.

  First, as shown in FIG. 1A, a first ceramic green sheet layer 2 is formed on a support 1, and then, as shown in FIG. The ceramic green sheet layer 3 is formed to form the ceramic green sheet 4.

  As the first ceramic green sheet layer 2 and the second ceramic green sheet layer 3 in the present invention, a mixture of ceramic powder, an organic binder, a solvent and the like is used. The first ceramic green sheet layer further contains a molten component. In both the first ceramic green sheet layer 2 and the second ceramic green sheet layer 3, a plasticizer may be further added to adjust the hardness and strength of the ceramic green sheet 4.

Examples of the ceramic powder 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 and PbTiO ₃ systems for a multilayer capacitor. Composite perovskite-based ceramic powders, and the like, are selected as appropriate in accordance with characteristics required for electronic components.

Examples of the glass component of the glass ceramic powder include SiO ₂ —B ₂ O ₃ system, SiO ₂ —B ₂ O ₃ —Al ₂ O ₃ system, SiO ₂ —B ₂ O ₃ —Al ₂ O ₃ —MO system (however, , 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 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 system (where M ³ is the same as above) Pb-based glass, Bi-based 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 blended in the ceramic green sheet layer 4, those conventionally used for ceramic green sheets can be used. For example, acrylic (acrylic acid, methacrylic acid or ester homopolymers or copolymers thereof are used. Polymer, specifically acrylic acid ester copolymer, methacrylic acid ester copolymer, acrylic acid ester-methacrylic acid ester copolymer, etc.), polyvinyl butyral, polyvinyl alcohol, acrylic-styrene, Examples thereof include homopolymers or copolymers such as polypropylene carbonate and cellulose. In view of decomposition and volatility in the firing step, an acrylic binder is more preferable.

  The molten component contained in the first ceramic green sheet layer 2 is in a molten state upon heating when the ceramic green sheet laminate 6 is produced, and is a hydrocarbon, fatty acid, ester, fatty alcohol, polyhydric alcohol. Etc. Considering the solubility in a solvent when preparing the slurry, hydrocarbons, esters, fatty alcohols and polyhydric alcohols having a small molecular weight and polarity are preferred. Further, in view of compatibility with the above-described acrylic binder, esters, fatty alcohols, and polyhydric alcohols are more preferable.

  Among the above-mentioned melting components, those having a melting point of 35 to 100 ° C. are preferred. This is because when the melting point in this range is used, the first ceramic green sheet layer 2 is not softened and deformed at room temperature. This is because organic components such as a binder and a plasticizer in the ceramic green sheet 4 are not decomposed during heating in the production process, and therefore delamination is not generated by the decomposition gas. Specific 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 first ceramic green sheet layer 2 varies depending on the binder component to be used and the amount thereof and the molten component to be used, but the first ceramic green sheet layer 2 is in a melted state. Is softened and may be deformed so as to follow the shape of the second ceramic green sheet layer 3 of the ceramic green sheet 4 located below and the shape of the conductor pattern formed thereon.

  Moreover, it is preferable that the thickness of the 1st ceramic green sheet layer 2 is 10-200 micrometers. If this is a thickness within this range, the second ceramic green sheet layer 3 of another ceramic green sheet positioned below the first ceramic green sheet layer 2 in the step of forming the laminate 6 will be described. This is because it deforms following the shape of the conductor pattern formed thereon and can suppress deformation during lamination.

  The tensile properties of the second ceramic green sheet layer 3 are preferably a yield point strength of 0.5 MPa or more and a yield point elongation of 50% or less. This is because the first ceramic green sheet layer softened during heating is the second ceramic green sheet layer 2 when the tensile property of the second ceramic green sheet layer 3 is a yield point strength of 0.5 MPa or more in the step of producing the laminate 6. If the ceramic green sheet layer 3 can be held without cracks or defects, and the yield point elongation is 50% or less, even if the first ceramic green sheet layer 2 is softened, the ceramic green sheet 4 is not deformed during lamination. This is because the accuracy dimension can be maintained.

  In addition, the yield point elongation of the first ceramic green sheet layer is preferably 50% or less. This is because, when including a step of forming a through hole in the ceramic green sheet by punching, if the yield point elongation of the first ceramic green sheet layer is greater than 50%, deformation of the through hole is likely to occur when punching. It is.

  In order to set the tensile properties of the ceramic green sheet layer to a yield point strength of 0.5 MPa or more and a yield point elongation of 50% or less, or a yield point elongation of 50% or less, an organic binder or plasticizer contained in the ceramic green sheet layer This can be achieved by adjusting the glass transition point of the organic binder. For example, when the amount of the organic binder or plasticizer is increased, the yield point elongation can be increased, and when the glass transition point of the organic binder is increased, the yield point strength can be increased.

Furthermore, the Cobb size of the second ceramic green sheet layer is preferably 50 to 500 g / m ² . In this case, when the conductor layer is formed by printing the conductor paste on the second ceramic green sheet layer of the ceramic green sheet by screen printing or gravure printing, the conductor paste to the second ceramic green sheet layer Since the absorption of the solvent therein is moderate, it is possible to form a highly accurate conductor layer free from defects. Further, it is possible to prevent the softening temperature of the first ceramic green sheet layer from being lowered by the solvent in the conductor paste passing through the second ceramic green sheet layer and penetrating into the first ceramic green sheet layer. It becomes possible.

If the cobb size is less than 50 g / m ² , the second ceramic green sheet layer absorbs less solvent in the conductor paste, and the conductor paste solvent that cannot be absorbed causes bleeding and poor drying of the conductor layer. It becomes easy to do. Therefore, when the conductor layers of the ceramic green sheets are stacked and laminated, the conductor layers in which bleeding or poor drying occurs are short-circuited with the adjacent conductor layers, or the interval between the adjacent conductor layers becomes narrow, and the ceramic green sheet laminate As a result, the insulation between the wirings of the wiring conductors of the electronic component mounting board formed by firing the substrate is caused.

If the Cobb sizing degree is larger than 500 g / m ² , the second ceramic green sheet layer absorbs much of the solvent in the conductor paste, and the solvent in the conductor paste passes through the second ceramic green sheet layer and passes through the first ceramic green sheet layer. In some cases, the solvent penetrates to the ceramic green sheet layer, the molten component dissolves and swells in the solvent, and the freezing point (melting point) of the molten component is lowered. As a result, the first ceramic green sheet layer softens and has adhesiveness at room temperature without heating, and handling during processing up to the laminating process or during conveyance may be worsened. Also, since the second ceramic green sheet layer absorbs a lot of solvent in the conductor paste and is fast, the conductor paste flows before the printed conductor paste flows and becomes a conductor pattern shape by leveling. As a result, there is no longer a solvent to be used, and the conductor layer is likely to be damaged or broken.

In order to set the cobb size of the second ceramic green sheet layer to 50 to 500 g / m ² , the amount of the organic binder contained in the second ceramic green sheet layer is increased or a plasticizer is added. Can be adjusted.

  The first ceramic green sheet layer 2 is a slurry obtained by adding a solvent (organic solvent, water, etc.) to the above ceramic powder, organic binder, and molten component, and a predetermined amount of plasticizer and dispersant as required. It is obtained by molding on a support such as a PET film by a doctor blade method, a lip coater method, a die coater method or the like. The thickness of the first ceramic green sheet layer 2 is formed to be thicker than the thickness of the conductor layer in order to fill the step between the conductor layer and the ceramic green sheet.

  The second ceramic green sheet layer 3 is formed using a slurry that does not contain a molten component with respect to the slurry used for the first ceramic green sheet layer 2.

  The method of forming the second ceramic green sheet layer 3 on the first ceramic green sheet layer 2 is as follows. (1) The second ceramic green sheet layer 3 formed in the same manner as the first ceramic green sheet layer 2 is (2) A slurry of the second ceramic green sheet 3 is applied on the first ceramic green sheet layer 2 formed on the support 1. And (3) a method in which the slurry of the second ceramic green sheet layer 3 is applied on the slurry of the first ceramic green sheet layer 2 applied on the support 1.

  When the second ceramic green sheet layer 3 is laminated on the first ceramic green sheet layer 2, a gap is generated between the first ceramic green sheet layer 2 and the second ceramic green sheet layer 3. In order to improve the adhesion between the first ceramic green sheet layer 2 and the second ceramic green sheet layer 3, the method (2) or (3) is preferable. Furthermore, the method (3) is more preferable because the first ceramic green sheet layer 2 and the second ceramic green sheet layer 3 are formed almost at the same time, which simplifies the process. In the method (3), an extrusion method such as a die coater method or a lip coater method may be used. These are non-contact coating methods, and a slurry having a relatively low viscosity and a small amount of solvent is used. Since it can be used, the ceramic green sheet 4 may be formed without mixing the slurry of the first ceramic green sheet layer 2 and the slurry of the second ceramic green sheet layer 3.

  Next, as shown in FIG. 1C, the conductor layer 4 is formed on the second ceramic green sheet layer 3 of the ceramic green sheet 4. As a method of forming the conductor layer 5 on the ceramic green sheet 4, for example, a paste formed from a conductor material powder is printed by a screen printing method or a gravure printing method, or a predetermined pattern shape is formed by a plating method or a vapor deposition method. A method of directly forming on the ceramic green sheet 4 to form a metal film, a conductor thick film formed into a predetermined pattern shape by printing, a metal foil processed into a predetermined pattern shape, a predetermined method formed by a plating method, a vapor deposition method, or the like There is a method of transferring a pattern-shaped metal film onto the ceramic green sheet 4. 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 layer 5 is formed on the second ceramic green sheet layer 3 of the ceramic green sheet 4. This is because since the second ceramic green sheet layer 3 does not contain a melting component that melts when heated, the second ceramic green sheet layer 3 is not deformed when heated, so that the conductor layer 5 is formed thereon. This is to prevent the conductor layer 5 from being deformed.

  In addition, before forming the conductor layer 5, if necessary, a through conductor such as a via-hole conductor or a through-hole conductor for connecting the conductor layers 5 between the upper and lower layers may be formed. These through conductors are formed by means such as embedding, by printing or press filling, a paste obtained by forming a conductive material powder into a through hole formed in the ceramic green sheet 4 by punching or laser processing.

  When the ceramic green sheet 4 includes a step of forming a through hole by punching, the yield point elongation of the ceramic green sheet layer on the punching start surface side is 50% or less, and the yield of the ceramic green sheet layer on the punching end surface side is The point elongation is preferably 20% to 50%. This is because when the yield point elongation of the ceramic green sheet layer on the punching end surface side is less than 20%, the punching end surface side is pulled by a punching die or a pin when the ceramic green sheet is punched. This is because cracks are likely to occur due to the stress, and if it is larger than 50%, deformation of the through hole is likely to occur when punching. Further, when the punching die or pin is punched from the ceramic green sheet 4 after the ceramic green sheet 4 is punched, the punching start surface is caused by friction between the inner wall surface of the through hole and the side surface of the punching die or pin. When the yield point elongation of the ceramic green sheet layer on the punching start surface side is larger than 50%, the pulled portion tends to extend and become burrs. This is because burrs are likely to occur in the opening. On the punching start surface side, even when the yield point elongation is small, the stress at the time of punching is dispersed by the ceramic green sheet 4 below the punching start surface, so that the occurrence of cracks on the punching start surface is easily suppressed.

  More preferably, the second ceramic green sheet layer 3 is on the punching start surface side, and the first ceramic green sheet layer 2 is on the punching end surface side. This is because the temperature of the punching die or pin is increased by repeatedly punching, and the first ceramic green sheet layer is brought into contact with the surface of the punching die or pin that is in contact with the first ceramic green sheet layer 2. This is because there is a case where 2 is attached and a favorable through hole cannot be formed.

  In the case of manufacturing an electronic component having a cavity, a cavity-shaped through hole is formed in a part of the ceramic green sheet 4 by punching with a mold or the like before the step of manufacturing the next laminate. The through hole may be formed before or after the conductor layer 5 is formed, depending on whether or not the conductor layer 5 is formed on the inner wall surface of the cavity.

  Next, as shown in FIG. 1 (d), the stacked ceramic green sheets 4 are aligned at a temperature at which the molten component becomes molten and the first ceramic green sheet layer 2 is softened and deformed, that is, the molten component. The ceramic green sheet laminated body 6 is produced by heating at a temperature of about the melting point. At this time, the laminated ceramic green sheets 4 are not displaced, and the softened first ceramic green sheet layer 2 is replaced with the second ceramic green sheet layer 3 and the conductor layer 5 formed thereon. If pressurizing is performed to assist in deforming following the pattern shape, more accurate and reliable pressing can be performed.

  In the step of producing the ceramic green sheet laminate 6, the first ceramic green sheet layer 2 contains a melting component that melts when heated, and thus the ceramic green sheet 4 on which the conductor layer 5 is formed is laminated and heated. At this time, the first ceramic green sheet layer 2 is softened, so that the first ceramic green sheet layer 2 is the second ceramic green sheet layer 3 of the ceramic green sheet 4 located thereunder and the conductor formed thereon. Deformation follows the shape of the layer 5. As a result, the ceramic green sheets 4 are brought into close contact with each other without generating voids around the conductor layer 5 or between the conductor layers 5, and the electronic component obtained by firing the ceramic green sheet laminate 6 is free from delamination. It will not be.

  In addition, since the first ceramic green sheet layer 2 contains a melting component that melts when heated, the first ceramic green sheet layer 2 is softened and has adhesiveness only by heating. There is no need to press the ceramic green sheet 4 by pressure. And since the 2nd ceramic green sheet layer 3 in which the conductor layer 5 is formed does not contain the fusion | melting component which melt | dissolves at the time of a heating, the 2nd ceramic green sheet layer 3 does not deform | transform at the time of a heating, and laminated ceramic The green sheet 4 is not displaced, and the softened first ceramic green sheet layer 2 is deformed following the pattern shape of the second ceramic green sheet layer 3 and the conductor layer 5 formed thereon. It will not be deformed to the extent that it is pressed to assist it. Accordingly, the ceramic green sheet 4 and the conductor layer formed thereon are not deformed, and the ceramic green sheet laminate 6 obtained by firing without distortion to the green sheet due to pressurization is obtained. The obtained electronic component has high dimensional accuracy.

  For example, when the first ceramic green sheet layer 2 that does not contain a melting component that melts when heated is used, the dimensional accuracy of the ceramic green sheet laminate 6 and the electronic component was about ± 0.5%. When the first ceramic green sheet layer 2 containing the molten component was used, the dimensional accuracy of the ceramic green sheet laminate 6 and the electronic component was about ± 0.3%, and it was proved by experiment that .

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

  As the ceramic green sheet positioned at the bottom of FIG. 1 (d), a ceramic green sheet 4 'composed only of the second ceramic green sheet layer 3 may be used. In the case of an electronic component in which the conductor layer 5 is not exposed on the surface, such as a multilayer capacitor, the ceramic green sheet 4 in which the conductor layer 5 is not formed on the ceramic green sheet 4 positioned at the top of FIG. In the case of an electronic component in which the conductor layer 5 is exposed on both surfaces, such as a multilayer ceramic wiring board, the one in which the conductor layer 5 is formed on both surfaces of the lowermost ceramic green sheet 4 ′ may be used. .

  Finally, the ceramic green sheet laminate 6 is fired to produce the electronic component of the present invention. The firing step consists of removing organic components and sintering the ceramic powder. The organic component is removed by heating the ceramic green sheet laminate 6 in a temperature range of 100 to 800 ° C., the organic component is decomposed and volatilized, and the sintering temperature varies depending on the ceramic composition, and is in the range of about 800 to 1600 ° C. Do it within. 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.

  After firing, the surface of the conductive layer 5 exposed on the surface of the electronic component is provided with a good connection means for preventing corrosion of the conductive layer 5 or for connecting the external substrate such as solder or metal wire or the electronic component. 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 green sheet laminate 6 and fired, and the restraint sheet is removed after firing, A ceramic substrate with higher dimensional accuracy 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. If the constraining green sheet at this time is also configured to have a first ceramic green sheet layer 2 and a second ceramic green sheet layer 3 similar to the ceramic green sheet 6 of the present invention, the constraining green sheets are laminated and pressure-bonded. In particular, a large pressing force is not required, and the obtained electronic component may have a higher dimensional accuracy.

  In addition to the hardly sinterable inorganic component, the constrained green sheet may contain a glass component having a softening point not higher than the firing temperature, for example, the same glass as the glass in the ceramic green sheet 4. This is because the glass softens and bonds with the ceramic green sheet 4 during firing, so that the bond between the ceramic green sheet 4 and the constraining green sheet becomes strong, and a more reliable restraining force can be obtained. When the glass amount at this time is 0.5 to 15% by mass with respect to the inorganic component including the hardly sinterable inorganic component and the glass component, the binding force is improved and the firing shrinkage of the constraint green sheet is 0.5%. It is suppressed to the following.

  After firing, the constraining sheet is removed. Examples of the removal method include polishing, water jet, chemical blasting, sand blasting, wet blasting (a method of spraying abrasive grains and water by air pressure) and the like.

  The electronic component manufactured by the method as described above does not have delamination inside and has high dimensional accuracy, and thus has excellent electrical characteristics and high airtightness required as an electronic component.

  Hereinafter, the present invention will be described in detail with specific examples, but the present invention is not limited to the following specific examples.

  First, for the first ceramic green sheet layer, 90% by mass of alumina having an average particle diameter of 1 μm, 10% by mass of silica, magnesia, and calcia as sintering aids and transition metal oxides as coloring pigments. 10 parts by mass of isobutyl methacrylate resin as a solid content and 10 parts by mass of hexadecanol as a melting component having a melting point of 48 ° C. are added to 100 parts by mass of the ceramic powder prepared at a ratio of The slurry was prepared by mixing for 40 hours with a ball mill using ethyl acetate as a solvent.

  Next, for the second ceramic green sheet layer, 90% by mass of alumina having an average particle diameter of 1 μm, silica, magnesia, and calcia as sintering aids, and transition metal oxide (chromium trioxide) as coloring pigments are combined. 100 parts by mass of ceramic powder prepared at a ratio of 10% by mass, 10 parts by mass of a methyl methacrylate resin as an organic binder in solid content and 1 part by mass of dibutyl phthalate as a plasticizer are added, and toluene and ethyl acetate Was mixed for 40 hours by a ball mill using as a solvent to prepare a slurry.

  From these slurries, a die coater sheet molding machine was used to form the first ceramic green sheet layer with a thickness of 20, 20, 40, 50, 100, 150, 200 under the conditions of a molding speed of 2 m / min and a molding sheet width of 250 mm. , 250 μm, and the second ceramic green sheet layer was formed as it was with a thickness of 50 μm to form a ceramic green sheet.

  On the second ceramic green sheet layer of the ceramic sheet, a conductor paste containing tungsten powder as a main component was printed in a predetermined pattern with a thickness of 10 to 20 μm by screen printing to form a conductor layer.

  Four layers of ceramic green sheets with conductor layers are stacked on top of each other and heat-pressed at a pressure of 0.5 MPa and a temperature of 80 ° C. in the thickness direction to produce a ceramic green sheet laminate. Measured with a machine. By calculating the maximum error with respect to the average value of the measured values before and after the lamination as the dimensional variation, the variation variation was evaluated, and a value within ± 0.3% was regarded as a non-defective product.

Then, in order to remove organic components such as an organic binder in the obtained ceramic green sheet laminate and carbon remaining after decomposition of the organic components, about 1000 in a nitrogen atmosphere containing 7.33 × 10 ³ Pa of water vapor. After performing heat treatment for 1 hour at a temperature of ° C., a ceramic sintered body for evaluation was manufactured by holding at a temperature of about 1600 ° C. for 1 hour in a reducing atmosphere.

  The sintered body was cross-sectioned and examined for the occurrence of delamination between the ceramic layers.

Table 1 shows the results of evaluation for each thickness of the first ceramic green sheet layer.

  In the column of inner layer delamination in Table 1, “◯” indicates that no delamination was observed inside the sintered body, which was excellent. “Δ” indicates that delamination was observed inside the sintered body although there was no problem in the formation of the laminate.

  In the dimension variation column, “○” indicates deformation variation by calculating the maximum error with respect to the average value of the measured values before and after lamination, and the value is excellent within ± 0.3%. It shows that. “Δ” indicates that it exceeds ± 0.3%.

  From Table 1, sample No. 1 in which the thickness of the first ceramic green sheet layer is less than 20 μm is used. In No. 1, delamination occurred inside the sintered body.

  In addition, sample No. 1 in which the thickness of the first ceramic green sheet layer is larger than 200 μm. In 8 and 9, the dimensional variation exceeded 0.3%.

  On the other hand, sample No. 1 having a thickness of 20 to 200 μm of the first ceramic green sheet layer. Nos. 2 to 7 were excellent with no delamination and a dimensional variation of less than ± 0.3%.

  As in Example 1, for the first ceramic green sheet layer, first, 90% by mass of alumina having an average particle diameter of 1 μm, silica, magnesia, calcia as sintering aids, and transition metal oxides as coloring pigments 10 parts by mass of ceramic powder prepared at a ratio of 10% by mass, 10 parts by mass of isobutyl methacrylate resin as an organic binder in solid content, and 10 parts of hexadecanol as a melting component having a melting point of 48 ° C. A part by mass was added, and toluene and ethyl acetate were used as a solvent and mixed by a ball mill for 40 hours to prepare a slurry.

  Next, for the second ceramic green sheet layer, 90% by mass of alumina having an average particle diameter of 1 μm, silica, magnesia, calcia as a sintering aid, and transition metal oxide (chromium trioxide) as a coloring pigment are used. Combined with 100 parts by mass of ceramic powder prepared at a ratio of 10% by mass, 10 parts by mass of methyl methacrylate resin as a solid content as an organic binder, and as a plasticizer for adjusting the tensile properties of the second ceramic green sheet layer 1-10 parts by mass of dibutyl phthalate was added.

  Thereafter, toluene and ethyl acetate were mixed in a ball mill for 40 hours as a solvent to prepare a slurry.

  The first ceramic green sheet layer was formed with a thickness of 50 μm from these slurries using a die coater sheet forming machine under the conditions of a forming speed of 2 m / min and a forming sheet width of 250 mm. The sheet layer was formed with a thickness of 50 μm to form a ceramic green sheet with a total thickness of 100 μm.

  On the second ceramic green sheet layer of the ceramic sheet, a conductor layer containing tungsten powder as a main component was printed in a predetermined pattern by a screen printing method to form a conductor layer.

  Four layers of ceramic green sheets with conductor layers are stacked on top of each other and heat-pressed in the thickness direction at a pressure of 0.5 MPa and a temperature of 80 ° C. to produce a ceramic green sheet laminate, and the dimensions after lamination are measured three-dimensionally Measured with a machine. By calculating the maximum error with respect to the average value of the measured values before and after the lamination as the dimensional variation, the variation variation was evaluated, and a value within ± 0.3% was regarded as a non-defective product.

Table 2 shows the results of evaluation according to tensile properties of the second ceramic green sheet layer.

  In the column of cracks in Table 2, “◯” indicates that the laminate was excellent without cracks. “Δ” indicates that there was no problem in the function of the laminate, but cracks were observed in the laminate.

  In the dimension variation pass / fail column, “○” indicates deformation variation by calculating the maximum error with respect to the average value of the measured values before and after lamination, and the value is excellent within ± 0.3%. It shows that. “Δ” indicates that it exceeds ± 0.3%.

  Moreover, in the column of comprehensive judgment, “◯” indicates that there was no crack in the laminated body, and the deformation variation before and after the lamination was within ± 0.3%, which was excellent. Further, “Δ” indicates that a crack in the laminate was observed, or that the variation variation before and after the lamination exceeded ± 0.3%.

  As is clear from the results in Table 2, the sample No. 2 with a yield point strength of less than 0.5 MPa of the second ceramic green sheet layer was obtained. In 1 and 8, cracks occurred in the laminate. It is considered that the second ceramic green sheet layer having a low yield point strength could not be held by the first ceramic green sheet layer being softened and deformed.

  Sample No. 2 with a yield point elongation of the second ceramic green sheet layer exceeding 50% was obtained. In No. 7, the variation variation slightly exceeded 0.3%.

  On the other hand, sample No. 2 having a yield point strength of 0.5 MPa or more and a yield point elongation of less than 50% of the second ceramic green sheet layer. Nos. 2, 3, 4, 5, and 6 did not generate cracks during lamination, and were excellent in deformation variation of less than ± 0.3%.

  As in Example 1, for the first ceramic green sheet layer, first, 90% by mass of alumina having an average particle diameter of 1 μm, silica, magnesia, calcia as sintering aids, and transition metal oxides as coloring pigments (Chromium trioxide) and 100 parts by mass of ceramic powder prepared at a rate of 10% by mass, as an organic binder, 10 parts by mass of isobutyl methacrylate resin as a solid component and a melting component having a melting point of 48 ° C. 10 parts by mass of hexadecanol was added and mixed with a ball mill for 40 hours using toluene and ethyl acetate as a solvent to prepare a slurry.

  Next, for the second ceramic green sheet layer, 90% by mass of alumina having an average particle diameter of 1 μm, 10% by mass of silica, magnesia, and calcia as sintering aids, and transition metal oxides as coloring pigments are combined. 10 parts by weight of methyl methacrylate resin as an organic binder in solid content, and 1 part of dibutyl phthalate as a plasticizer for adjusting the tensile properties of the second ceramic green sheet layer. -10 mass parts was added. Thereafter, toluene and ethyl acetate were mixed as a solvent by a ball mill for 40 hours to prepare a slurry.

  The first ceramic green sheet layer was formed with a thickness of 50 μm from these slurries using a die coater sheet forming machine under the conditions of a forming speed of 2 m / min and a forming sheet width of 250 mm, and the second ceramic green as it was. The sheet layer was formed with a thickness of 50 μm to form a ceramic green sheet with a total thickness of 100 μm.

Table 3 shows the results of evaluation of punchability when this ceramic green sheet was punched from the second ceramic green sheet layer side at a pitch of 1 mm using a pin having a diameter of 60 μm to form a through hole.

  In the column of cracks in Table 3, “◯” indicates that no crack was found in the ceramic green sheet layer around the through-holes, which was excellent. In addition, “Δ” indicates that cracks were observed in the green sheet layer around the through-hole, although there was no problem in the function as the through-hole.

  In the deformation column, “◯” indicates that the through hole was not deformed and was excellent. “Δ” indicates that the cross-sectional shape of the through hole was deformed due to elongation in the ceramic green sheet layer, although there was no problem in the function as the through hole.

  Further, in the column of burrs, “◯” indicates that no burrs were observed at the openings of the through holes, which was excellent. In addition, “Δ” indicates that although there is no problem in the function as the through hole, a burr has occurred in the opening of the through hole.

  As is apparent from the results in Table 3, the sample No. 1 with a yield point elongation of the first ceramic green sheet layer of less than 20% was obtained. 1 had cracks.

  Sample No. 1 with a yield point elongation of the first ceramic green sheet layer of more than 50% was obtained. 7 had deformation of the through hole.

  In addition, the sample No. of yield point elongation of the second ceramic green sheet layer is larger than 50%. In No. 6, burrs and through holes were deformed.

  On the other hand, sample No. 1 in which the yield point elongation of the first ceramic green sheet layer is 20% to 50% and the yield point elongation of the second ceramic green sheet layer is 50% or less. 2, 3, 5, and 6 were excellent without cracks, deformation of through-holes, and burrs.

Also, a conductor layer is formed on the second ceramic green sheet layer of the ceramic green sheet by printing a predetermined pattern with a thickness of 10 to 20 μm by a screen printing method using a conductive paste containing W as a main component. Four ceramic green sheets each having a layer formed thereon were stacked and heat-pressed at a pressure of 0.5 MPa and a temperature of 80 ° C. in the thickness direction to prepare a ceramic green sheet laminate. In order to remove organic components such as an organic binder in the obtained ceramic green sheet laminate and carbon remaining after the organic components were decomposed, about 1000 in a nitrogen atmosphere containing water vapor of 7.33 × 10 ³ Pa. A ceramic sintered body was produced by performing a heat treatment held at a temperature of 1 ° C. for 1 hour and then holding it at a temperature of about 1600 ° C. for 1 hour in a reducing atmosphere. However, there was no delamination and high dimensional accuracy. I was able to confirm that there was.

  First, for the first ceramic green sheet layer, 90% by mass of alumina having an average particle diameter of 1 μm, silica, magnesia and calcia as sintering aids, and transition metal oxide (chromium trioxide) as coloring pigments are used. 10 parts by mass of hexadecanol as a melting component having a solid content of 10 parts by mass of isobutyl methacrylate resin as an organic binder and a melting point of 48 ° C. with respect to 100 parts by mass of ceramic powder prepared in a proportion of 10% by mass. Then, toluene and ethyl acetate were used as solvents and mixed by a ball mill for 40 hours to prepare a slurry.

  Further, for the second ceramic green sheet layer, 10 parts by mass of a methyl methacrylate resin as an organic binder in a solid content with respect to 100 parts by mass of the ceramic powder similar to the first slurry, the second ceramic green sheet layer 1 to 10 parts by mass of dibutyl phthalate was added as a plasticizer for adjusting the Cobb size. Thereafter, toluene and ethyl acetate were mixed as a solvent by a ball mill for 40 hours to prepare a slurry.

  Next, using a die coater sheet molding machine, the first slurry is applied with a width of 250 mm at a molding speed of 2 m / min, and the second slurry is applied thereon and dried. A ceramic green sheet having a thickness of 1 ceramic green sheet layer of 50 μm and a thickness of the second ceramic green sheet layer of 50 μm was produced.

  The first ceramic green sheet layer of this ceramic green sheet uses a conductive paste prepared with tungsten powder, cellulose resin as the organic binder, and α-terpineol as the organic binder, and is 100 μm line width and thickness 20 μm by screen printing. The wiring conductor layer was formed.

  With respect to the printed conductor layer, the line width was measured with a three-dimensional measuring machine, and the printability was evaluated from the state of bleeding and blurring of the conductor layer.

  Further, the first ceramic green sheet layer was scraped from the ceramic green sheet on which the conductor layer was formed to make a sample, and the melting point of the molten component of the first ceramic green sheet layer was measured by differential thermal analysis.

Table 4 shows the measurement results of the printability of the second ceramic green sheet layer and the melting point of the first ceramic green sheet layer.

  In the column of printability in Table 4, “Δ” indicates that there is no problem in the function as the conductor layer, but a portion having a line width exceeding +20 μm or smaller than −20 μm occurs with respect to the 100 μm line width of the conductor layer. It shows that. “◯” indicates that every portion was within ± 20 μm with respect to the 100 μm line width of the conductor layer. In the melting point column, “◯” indicates that the melting point of the molten component of the first ceramic green sheet layer exceeds room temperature (25 ° C.). “Δ” indicates that the melting point of the molten component has become lower than room temperature.

From Table 4, sample No. ² having a Cobb size of the second ceramic green sheet layer of less than 50 g / m ² was obtained. 1 and Sample No. with a Cobb sizing degree greater than 500 g / m ² . 7 and 8 did not fall within ± 20 μm with respect to the line width of 100 μm. Sample No. No. 1 has a portion where the line width is increased due to bleeding. In No. 8, there was a portion where the line width was reduced by scraping. In addition, sample no. In Nos. 7 and 8, the melting point of the molten component of the first ceramic green sheet layer was lower than normal temperature (25 ° C.), and adhesiveness was exhibited at normal temperature.

On the other hand, sample No. ² having a Cobb size of the second ceramic green sheet layer of 50 to 500 g / m ² was used. Nos. 2 to 6 have no blurring or blurring of the conductor layer, excellent printability at any location within ± 20 μm with respect to the 100 μm line width of the conductor layer, and exhibit no adhesiveness at room temperature. It was easy to handle.

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

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Support body 2 ... 1st ceramic green sheet layer 3 ... 2nd ceramic green sheet layer 4 ... Ceramic green sheet 5 ... Conductive layer 6 ... Ceramic green sheet laminated body

Claims (7)

Forming a first ceramic green sheet layer on a support, forming a second ceramic green sheet layer on the first ceramic green sheet layer to form a ceramic green sheet, and the ceramic green A step of forming a conductor layer on the second ceramic green sheet layer of the sheet, and a step of preparing a ceramic green sheet laminate by laminating and heating a plurality of the ceramic green sheets on which the conductor layers are formed. And a step of firing the ceramic green sheet laminate, wherein the first ceramic green sheet layer contains a melting component that is in a molten state when heated when producing the ceramic green sheet laminate. A method for manufacturing an electronic component, characterized in that: The method for manufacturing an electronic component according to claim 1, wherein the melting component has a melting point of 35 to 100 ° C. 3. The method of manufacturing an electronic component according to claim 1, wherein the thickness of the first ceramic green sheet layer is 10 to 200 [mu] m. 4. The electronic component according to claim 1, wherein the tensile properties of the second ceramic green sheet layer are a yield point strength of 0.5 MPa or more and a yield point elongation of 50% or less. Manufacturing method. The method of manufacturing an electronic component according to any one of claims 1 to 4, wherein the yield point elongation of the first ceramic green sheet layer is 50% or less. Including a step of forming a through hole in the ceramic green sheet by punching, the yield point elongation of the ceramic green sheet layer on the punching start surface side is 50% or less, and the yield point elongation of the ceramic green sheet layer on the punching end surface side 6. The method of manufacturing an electronic component according to claim 1, wherein the degree is 20% to 50%. The method for manufacturing an electronic component according to claim 1, wherein the second ceramic green sheet layer has a Cobb size of 50 to 500 g / m ² .

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