WO2011102535A1 - Ceramic substrate, electrical circuit module, and method for producing each - Google Patents

Ceramic substrate, electrical circuit module, and method for producing each Download PDF

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Publication number
WO2011102535A1
WO2011102535A1 PCT/JP2011/053885 JP2011053885W WO2011102535A1 WO 2011102535 A1 WO2011102535 A1 WO 2011102535A1 JP 2011053885 W JP2011053885 W JP 2011053885W WO 2011102535 A1 WO2011102535 A1 WO 2011102535A1
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WO
WIPO (PCT)
Prior art keywords
via hole
ceramic substrate
green sheet
machining
laminate
Prior art date
Application number
PCT/JP2011/053885
Other languages
French (fr)
Japanese (ja)
Inventor
絵美 森田
森田　敏文
元紀 庄田
裕史 岡田
Original Assignee
パナソニック株式会社
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Publication of WO2011102535A1 publication Critical patent/WO2011102535A1/en

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L23/00—Details of semiconductor or other solid state devices
    • H01L23/48—Arrangements for conducting electric current to or from the solid state body in operation, e.g. leads, terminal arrangements ; Selection of materials therefor
    • H01L23/488—Arrangements for conducting electric current to or from the solid state body in operation, e.g. leads, terminal arrangements ; Selection of materials therefor consisting of soldered or bonded constructions
    • H01L23/498—Leads, i.e. metallisations or lead-frames on insulating substrates, e.g. chip carriers
    • H01L23/49827—Via connections through the substrates, e.g. pins going through the substrate, coaxial cables
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L23/00—Details of semiconductor or other solid state devices
    • H01L23/48—Arrangements for conducting electric current to or from the solid state body in operation, e.g. leads, terminal arrangements ; Selection of materials therefor
    • H01L23/488—Arrangements for conducting electric current to or from the solid state body in operation, e.g. leads, terminal arrangements ; Selection of materials therefor consisting of soldered or bonded constructions
    • H01L23/498—Leads, i.e. metallisations or lead-frames on insulating substrates, e.g. chip carriers
    • H01L23/49822—Multilayer substrates
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K3/00—Apparatus or processes for manufacturing printed circuits
    • H05K3/46—Manufacturing multilayer circuits
    • H05K3/4611—Manufacturing multilayer circuits by laminating two or more circuit boards
    • H05K3/4626—Manufacturing multilayer circuits by laminating two or more circuit boards characterised by the insulating layers or materials
    • H05K3/4629—Manufacturing multilayer circuits by laminating two or more circuit boards characterised by the insulating layers or materials laminating inorganic sheets comprising printed circuits, e.g. green ceramic sheets
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2224/00—Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
    • H01L2224/01—Means for bonding being attached to, or being formed on, the surface to be connected, e.g. chip-to-package, die-attach, "first-level" interconnects; Manufacturing methods related thereto
    • H01L2224/10—Bump connectors; Manufacturing methods related thereto
    • H01L2224/15—Structure, shape, material or disposition of the bump connectors after the connecting process
    • H01L2224/16—Structure, shape, material or disposition of the bump connectors after the connecting process of an individual bump connector
    • H01L2224/161—Disposition
    • H01L2224/16151—Disposition the bump connector connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive
    • H01L2224/16221—Disposition the bump connector connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive the body and the item being stacked
    • H01L2224/16225—Disposition the bump connector connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive the body and the item being stacked the item being non-metallic, e.g. insulating substrate with or without metallisation
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L23/00—Details of semiconductor or other solid state devices
    • H01L23/12—Mountings, e.g. non-detachable insulating substrates
    • H01L23/14—Mountings, e.g. non-detachable insulating substrates characterised by the material or its electrical properties
    • H01L23/15—Ceramic or glass substrates
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K1/00—Printed circuits
    • H05K1/02—Details
    • H05K1/11—Printed elements for providing electric connections to or between printed circuits
    • H05K1/111—Pads for surface mounting, e.g. lay-out
    • H05K1/112—Pads for surface mounting, e.g. lay-out directly combined with via connections
    • H05K1/113—Via provided in pad; Pad over filled via
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K2201/00—Indexing scheme relating to printed circuits covered by H05K1/00
    • H05K2201/09—Shape and layout
    • H05K2201/09209—Shape and layout details of conductors
    • H05K2201/095—Conductive through-holes or vias
    • H05K2201/096—Vertically aligned vias, holes or stacked vias
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K3/00—Apparatus or processes for manufacturing printed circuits
    • H05K3/40—Forming printed elements for providing electric connections to or between printed circuits
    • H05K3/4038—Through-connections; Vertical interconnect access [VIA] connections
    • H05K3/4053—Through-connections; Vertical interconnect access [VIA] connections by thick-film techniques
    • H05K3/4069—Through-connections; Vertical interconnect access [VIA] connections by thick-film techniques for via connections in organic insulating substrates

Definitions

  • the present invention relates to a ceramic substrate, an electric circuit module using the ceramic substrate, and a manufacturing method thereof. More specifically, the present invention relates to a ceramic substrate composed of a laminated fired body of green sheets and an electric circuit module using the same, and also relates to a method of manufacturing the ceramic substrate and the electric circuit module.
  • the ceramic substrate is excellent in heat resistance and moisture resistance, and may have good frequency characteristics in a high frequency circuit. Accordingly, the ceramic substrate is used as an RF (Radio Frequency) module of a mobile device, a substrate for a power LED (Light Emitting Diode) utilizing heat dissipation, and a substrate for an LED for a liquid crystal backlight. It is also used as a substrate for electronic equipment on which electronic components are mounted with high density.
  • RF Radio Frequency
  • Such a ceramic substrate can be obtained by laminating and firing a plurality of green sheets.
  • the ceramic substrate is provided with a via, and the via is formed by filling a via hole formed in a green sheet forming a laminated body with a conductive paste.
  • the via hole is a hole formed using a laser. That is, the conventional via hole is formed by irradiating the green sheet with laser light and melting and burning the green sheet component by the heat generated at that time (see International Publication No. 2008/111408).
  • the conventional via hole is formed by irradiating the green sheet with laser light and melting and burning the green sheet component by the heat generated at that time (see International Publication No. 2008/111408).
  • vias have become denser with the downsizing and higher performance of electronic equipment and can be processed finely at high speed without contact, so the use of laser light is the mainstream for forming via holes. .
  • the main object of the present invention is to provide a ceramic substrate that can suitably cope with the problem of the above-mentioned connection failure, thereby improving the yield at the time of manufacturing an electric circuit module including the ceramic substrate. is there.
  • At least one has a fired body formed by firing a laminate of a plurality of green sheets having via holes, and a via formed by filling a via hole with a conductive material,
  • a ceramic substrate is provided in which the via hole in the outermost green sheet on which the mounting electrode is provided is a “via hole formed by machining” with respect to the laminate.
  • a via hole is formed by machining in the outermost green sheet on which the mounting electrode is provided among the plurality of green sheets of the laminate forming the fired body.
  • via holes formed by machining are also referred to as “machined via holes” or “machined holes”).
  • the via located in the outermost layer is “a via formed by filling a machining hole with a conductive material”.
  • the “outermost layer green sheet” substantially means the outermost green sheet in a laminate obtained by stacking a plurality of green sheets.
  • the green sheet corresponding to the uppermost layer and / or the lowermost layer corresponds to the “outermost layer”.
  • the ceramic substrate of the present invention further includes an electrode provided on the fired body so as to be in contact with the via located in the outermost layer.
  • the via hole formed by machining has a constant width dimension along the thickness direction. That is, the cross section of the machined hole (hole cross section cut by a plane parallel to the thickness direction of the via hole) has a rectangular shape or a square shape. This means that the width dimension of a via formed by filling a machined hole with a conductive material is constant along the thickness direction, and therefore the cross-section of such via (via The via cross-section cut by a plane parallel to the thickness direction also means having a rectangular shape or a square shape.
  • the via hole in the green sheet other than the outermost layer green sheet is a via hole formed by laser processing (hereinafter referred to as “laser processed via hole” or Also called “laser machining hole”. That is, via holes of green sheets other than the corresponding green sheets of the uppermost layer and / or the lowermost layer (that is, green sheets located inside the laminate) are formed by laser processing. For example, only the via hole of the green sheet corresponding to the uppermost layer may be a machined hole, and all other via holes may be laser processed holes.
  • the via hole formed by laser processing can have a taper shape in the thickness direction. That is, the cross section of the laser processed via hole (the hole cross section cut by a plane parallel to the thickness direction of the via hole) has a trapezoidal shape. This means that the via formed in the laser processed via hole has a taper shape in the thickness direction, and therefore, the cross-section of the via (in a plane parallel to the via thickness direction). The cut via cross-section) also has a trapezoidal shape.
  • the present invention also provides an electric circuit module using the above-described ceramic substrate.
  • Such an electric circuit module is A mounting electrode provided on the fired body so as to be in contact with the via of the ceramic substrate, and an electronic component mounted on the mounting electrode via solder.
  • the electric circuit module of the present invention is A fired body formed by firing a laminate of a plurality of green sheets having via holes in at least one sheet; A via formed by filling a via hole with a conductive material, Electrodes provided on the fired body so as to be in contact with the vias, and electronic components mounted on the electrodes (particularly electronic components mounted on the electrodes via solder) Comprising In the laminate, the via hole of the green sheet corresponding to the outermost layer on which the electrode is provided is a via hole formed by machining.
  • One of the features of the electric circuit module according to the present invention is that a via hole is formed by machining in the outermost green sheet on which the mounting electrodes are provided, among the green sheets of the laminate forming the fired body of the ceramic substrate. It is that.
  • the present invention also provides a method for manufacturing the above-described ceramic substrate.
  • a method for producing a ceramic substrate of the present invention comprises: (I) forming a via hole in at least one of the plurality of green sheets; (Ii) filling a via hole with a conductive material, and (iii) forming a laminate by laminating a plurality of green sheets, and subjecting the laminate to firing to obtain a fired body.
  • step (i) a via hole of “a green sheet that is used as the outermost layer of the laminate and is provided with a mounting electrode” is formed by machining.
  • a via hole is formed by machining on the “outermost surface green sheet on which mounting electrodes are provided” among a plurality of green sheets constituting the laminate. It is to be.
  • the mounting electrode is formed on a via hole formed by machining (more specifically, a via formed by filling the machining hole with a conductive material).
  • a punch press is performed as machining. That is, the via hole of the outermost layer green sheet of the laminate is formed by performing punch press processing.
  • the via hole in the green sheet other than the green sheet provided as the outermost layer of the laminate is formed by laser processing. That is, via holes of green sheets other than the corresponding green sheets in the uppermost layer and / or the lowermost layer (green sheets located inside the laminate) are formed by laser processing.
  • the manufacturing method of the electrical circuit module using the ceramic substrate obtained by the above-mentioned manufacturing method is also provided.
  • Such a method of manufacturing an electric circuit module of the present invention includes: (I) forming a mounting electrode on the ceramic fired body so as to be in contact with the via of the ceramic substrate; (II) a step of providing solder on the electrodes of the ceramic substrate, and placing electronic components on the solder; and (III) reflow soldering integrally with the ceramic substrate, the electrical components and the solder interposed therebetween. (Ie, a process of subjecting the ceramic substrate, the electronic component, and the solder interposed therebetween to heat treatment) Comprising.
  • the manufacturing method of the electric circuit module of the present invention is: (I) forming a via hole in at least one of the plurality of green sheets; (Ii) filling a via hole with a conductive material, and (iii) forming a laminated body by laminating a plurality of green sheets, and then subjecting the laminated body to firing to obtain a fired body.
  • step (I) A step of forming an electrode on the fired body so as to be electrically connected to the via
  • step (II) A step of placing an electronic component on the solder after providing the solder on the electrode
  • step (III) In order to perform reflow soldering, the method further includes a step of subjecting the ceramic substrate, the electronic component, and the solder interposed therebetween to a heat treatment, In step (i), a via hole of a green sheet provided as the outermost layer of the laminate is formed by machining, and in step (I), an electrode is formed on the via hole formed by machining (more specifically, The electrode is formed so as to be in contact with “a via formed by filling a machining hole with a conductive material”).
  • One of the features of the method of manufacturing an electric circuit module according to the present invention is that “the outermost green sheet on which mounting electrodes are provided” among a plurality of green sheets constituting a laminate for forming a ceramic substrate.
  • a via hole is formed by machining, and solder is disposed on the via of the machined via hole to perform reflow soldering.
  • a via hole (especially a via hole formed for a via connected to a mounting electrode) in the outermost green sheet of a “laminated body composed of a plurality of green sheets” is a machine. Since it is obtained by machining, “residue generation during via hole formation” due to heat is avoided, and as a result, “all the spaces in the machined via hole are sufficiently filled with the conductive material. A “via” will be obtained. This effectively prevents “voids that can occur inside the solder during the solder reflow process” and, as a result, improves the yield when manufacturing electronic circuit modules by mounting electronic components on a ceramic substrate. To do.
  • the present invention can improve the process yield in the production of a ceramic substrate and, in the production of an electric circuit module using the ceramic substrate, without substantially adversely affecting the tact time in the production of the ceramic substrate. Very beneficial.
  • FIG. 1 is a photographic diagram showing residues (melted residue / combustion residue) generated when a via hole is formed by irradiating a green sheet with laser light.
  • FIG. 2 (FIG. 2) is a photograph showing a phenomenon in which voids are generated in the solder and the solder explodes and scatters.
  • FIG. 3 (FIG. 3) is a schematic cross-sectional view of a laminate for explaining the “outermost layer green sheet”.
  • 4 (FIG. 4) is a perspective view schematically showing an aspect of the ceramic substrate of the present invention.
  • 5 (FIG. 5) is a cross-sectional view schematically showing an aspect of the ceramic substrate of the present invention.
  • Fig. 6 (Fig.
  • FIG. 6 is a schematic view showing a mode of a laser processed via hole (Fig. 6 (a): plan view, Fig. 6 (b): cross section taken along line aa in Fig. 6 (a)).
  • Fig. 7 (Fig. 7) is a schematic diagram showing a mode of a machined via hole (Fig. 7 (a): plan view, Fig. 7 (b): cross section taken along line bb in Fig. 7 (a)).
  • Figure) 8 (FIG. 8) is a schematic cross-sectional view of a green sheet for explaining the via hole dimensions.
  • FIG. 9 (FIG. 9) is a perspective developed view schematically showing an aspect of the green sheet laminate. 10 (FIG.
  • FIG. 11 is a cross-sectional view schematically showing an aspect of the electric circuit module of the present invention.
  • 12 is a photograph showing the form of via holes formed in the green sheet (FIG. 12 (a): laser processed via hole, FIG. 12 (b): machined via hole).
  • 13 is a perspective view and a cross-sectional view schematically showing an aspect of the method for producing a ceramic substrate of the present invention.
  • 14 is a cross-sectional view schematically showing an aspect of the method for manufacturing the electric circuit module of the present invention.
  • 15 (FIG.
  • FIG. 15 is a cross-sectional view schematically showing an aspect of the ceramic substrate (substrate for double-sided mounting) of the present invention.
  • 16 is a perspective view schematically showing only the entire shape of a typical via / via hole of the ceramic substrate of the present invention (FIG. 16 (a): via / via hole in a single-sided mounting substrate.
  • FIG. 16B Overall shape of vias and via holes in a double-sided mounting board).
  • Fig. 17 (Fig. 17) is a photograph showing the results of the effect confirmation test of the present invention (Fig. 17 (a): Comparative Example 1, Fig. 17 (b): Example 1).
  • the ceramic substrate 100 of the present invention includes a fired body 4 and vias 6 formed in the fired body.
  • the fired body 4 of the ceramic substrate is formed by firing a laminate of a plurality of green sheets each having a via hole.
  • the via 6 provided in the fired body 4 is formed by filling the via hole 2 (2A, 2B) of the green sheet with a conductive material.
  • the “green sheet 1B in which via holes 2B are formed by machining” is used on the side on which the mounting electrodes 7 are formed.
  • “green sheet 1A in which via hole 2A is formed by irradiating laser light” is used, and “ceramic sheet 1C having no via hole” is also used as necessary. That is, in the ceramic substrate 100 of the present invention, among the plurality of green sheets (1A, 1B, 1C,...) Of the laminate forming the fired body 4, the outermost layer green sheet (1B) on which the mounting electrode 7 is provided.
  • the via hole (2B) in (1) forms a hole formed by machining.
  • the plurality of green sheets constituting the green sheet laminate are “the outermost layer green sheet 1B having the machined via hole 2B” and “the laser processed via hole 2A”. And at least a combination with the provided internal green sheet 1A ”.
  • FIG. 5 there is one “green sheet 1C without via holes”, six “green sheets 1A with via holes 2A formed by irradiating laser light” thereon, and further, “Green sheet 1B having via hole 2B as a top layer by machining” is formed by sequentially laminating one sheet.
  • the via holes 2A and 2B of each green sheet are filled with a conductive paste, and then the via hole 2B formed by machining is formed on the side where the mounting electrode 7 is formed.
  • a plurality of green sheets (1A, 1B, 1C) are laminated and fired so that "" is positioned.
  • FIG. 6 shows the configuration of a green sheet 1A provided with via holes 2A formed by laser light irradiation
  • FIG. 7 shows the configuration of a green sheet 1B provided with via holes 2B formed by machining.
  • the via hole 2 ⁇ / b> A formed by laser processing can have a taper shape in the hole thickness direction due to the spread angle of the laser beam.
  • the taper angle ⁇ of the via hole 2A having such a tapered shape is approximately 45 ° to 80 °, for example, 50 ° to 70 ° (see FIG. 6). Due to such a taper shape, the cross section of the via hole 2A formed by laser processing (hole cross section cut along a plane parallel to the thickness direction of the via hole) is substantially as shown in FIG. It can have a trapezoidal shape.
  • the via hole 2A has a “tapered shape” / “substantially trapezoidal shape” means that the via 6A formed in the via hole also has a tapered shape in the thickness direction. This means that the cross section of the via (via cross section cut by a plane parallel to the thickness direction of the via) also has a trapezoidal shape.
  • the “via hole 2A formed by laser processing”, that is, the “via 6A” has the following width dimensions (w A1 , w A2 ) and height dimensions (h A ).
  • ⁇ Via hole and via width and height due to laser processing ⁇ w A1 : 80 to 170 ⁇ m (for example, 100 to 150 ⁇ m)
  • ⁇ W A2 110 to 200 ⁇ m (for example, 130 to 180 ⁇ m)
  • ⁇ H A 60 to 350 ⁇ m (for example, 150 to 300 ⁇ m)
  • the via hole 2B formed by machining can have a substantially constant width along the hole thickness direction due to the machining (the inner wall of the via hole and the surface of the green sheet).
  • the angle ⁇ formed by is substantially a right angle ⁇ 90 °). That is, the cross section of the via hole 2B formed by machining (hole cross section cut along a plane parallel to the thickness direction of the via hole) has a substantially rectangular shape or a substantially square shape as shown in FIG. is doing.
  • the via hole 2B having “constant width direction dimension” / “substantially rectangular shape / substantially square shape” means that the width dimension of the via 6B formed in the via hole is also in the via thickness direction.
  • the cross-section of the via via cross-section cut by a plane parallel to the thickness direction of the via
  • the “via hole 2B formed by machining”, that is, the “via 6B” has the following width dimension (w B ) and height dimension (h B ) ranges.
  • w B width dimension
  • h B height dimension
  • FIG. 8B ⁇ Via hole and via width and height due to machining
  • ⁇ w B 80 ⁇ 170 ⁇ m (eg 100 ⁇ 150 ⁇ m)
  • ⁇ H B 60 to 350 ⁇ m (for example, 150 to 300 ⁇ m)
  • the green sheet itself may be a sheet-like member including a ceramic component, a glass component, and an organic binder component.
  • the ceramic component may be alumina powder (average particle size: about 0.5 to 10 ⁇ m)
  • the glass component may be borosilicate glass powder (average particle size: about 1 to 20 ⁇ m).
  • the organic binder component may be at least one component selected from the group consisting of polyvinyl butyral resin, acrylic resin, vinyl acetate copolymer, polyvinyl alcohol and vinyl chloride resin, for example.
  • the green sheets (1A, 1B, and 1C) may be 40 to 50 wt% alumina powder, 30 to 40 wt% glass powder, and 10 to 30 wt% organic binder components, which are merely examples. Based on total weight). From another viewpoint, the green sheets (1A, 1B, 1C) are composed of a solid component (alumina powder 50-60 wt% and glass powder 40-50 wt%: based on the weight of the solid component) and an organic binder component. The weight ratio, that is, the solid component weight: organic binder component weight may be about 80 to 90:10 to 20.
  • the green sheet component other components may be included as necessary, and for example, a dispersant of ketones such as phthalate ester and glycol, an organic solvent, and the like may be included.
  • the thickness of the green sheets (1A, 1B, 1C) may be about 60 to 350 ⁇ m, for example, about 150 to 300 ⁇ m.
  • the vias 6A and 6B are formed by filling the via holes 2A and 2B with a conductive material. Specifically, the vias 6A and 6B are obtained by filling the via holes 2A and 2B with a conductive paste by a printing method or the like and subjecting to heat treatment or the like.
  • the conductive paste may include, for example, Ag powder, glass frit for obtaining adhesive strength, and an organic vehicle (for example, an organic mixture of ethyl cellulose and terpineol).
  • the heat treatment may be performed when the green sheet laminate is fired. Prior to firing the green sheet laminate, the conductive paste filled in the via holes 2A and 2B may be subjected to a drying process.
  • the fired body 4 constituting the ceramic substrate 100 of the present invention is obtained by laminating and firing a plurality of green sheets (1A, 1B, 1C).
  • the green sheet laminate 4 ′ before firing has “green sheet 1 ⁇ / b> A in which via hole 2 ⁇ / b> A is formed by irradiating laser light” and “via hole 2 ⁇ / b> B is formed by machining.
  • a predetermined number of “green sheets 1B” and “ceramic sheets 1C without via holes” provided as necessary are formed by thermocompression bonding (each green sheet has via filling and internal electrodes as necessary. Layer, wiring layer, etc. are provided by the printing method).
  • the fired body 4 is obtained by subjecting the green sheet laminate to firing.
  • the ceramic substrate 100 of the present invention may be provided with mounting electrodes 7 in advance.
  • the mounting electrode 7 may be provided on the fired body 4 so as to be in contact with the via 6 ⁇ / b> B (via hole 2 ⁇ / b> B) located in the outermost layer of the stacked body.
  • the electric circuit module of the present invention comprises an electronic component mounted on the ceramic substrate.
  • the electric circuit module 200 of the present invention as shown in FIG.
  • a fired body 4 formed by firing a laminate of a plurality of green sheets having via holes in at least one sheet;
  • a via 6 formed by filling a via hole with a conductive material;
  • Mounting electrode 7 provided on fired body 4 so as to be in contact with via 6 (particularly via 6B), and electronic component 10 mounted on mounting electrode 7 via solder 9 It has.
  • the mounting electrode 7 provided on the fired body 4 is provided so as to be electrically connected to the uppermost via 6B.
  • the mounting electrode 7 is provided on the via 6B so as to be in contact with the via 6B of the via hole 2B formed by machining.
  • the thickness of the electrode 7 may be about 2 to 150 ⁇ m.
  • Such an electrode 7 can be obtained by printing the conductive paste on the fired body 4 by screen printing or the like and subjecting it to a heat treatment.
  • the conductive paste for forming the mounting electrode 7 may be one that is conventionally used in forming a mounting electrode or an internal electrode of a general ceramic substrate. For example, Ag paste may be used.
  • the heat treatment may be performed during reflow soldering described later. Prior to the reflow soldering, the conductive paste printed for forming the electrode 7 may be subjected to a drying process.
  • the via 6 ⁇ / b> B located on the outermost layer on which the mounting electrode 7 is provided was formed by filling the machining hole with a conductive material. “Beer”.
  • the electric circuit module 200 of the present invention is obtained through a reflow soldering process. Specifically, the ceramic substrate 100 with the solder 9 interposed therebetween and the electronic component 10 are integrally subjected to heat treatment. Can be obtained.
  • the material of the solder 9 is not particularly limited as long as it can join the ceramic substrate 100 and the electronic component 10, for example, Sn—Ag system, Sn—Bi system, Sn—Cu system, Sn—In system, Binary alloy materials such as Sn-Pb or Sn-Sb, or Sn-Ag-Cu, Sn-Ag-Bi, Sn-Ag-Pb, Sn-Bi-In, Sn-Bi- It may be a ternary alloy material such as Pb, Sn—Zn—Bi, or Sn—Zn—Pb.
  • the electronic component 10 mounted on the electrode 7 of the ceramic substrate 100 is not particularly limited, but includes a semiconductor, a semiconductor IC, a circuit board (for example, a printed wiring board), a module component or a passive component. Can do.
  • a residue due to the heat due to the laser beam irradiation may be generated in the via hole 1A.
  • the ceramic substrate is configured by laminating only the green sheet 1A having the laser processed via hole 2A, if the amount of the residue is large, the “void in the via” generated due to the residue causes In the manufacturing process, moisture or bubbles can enter. Therefore, when the ceramic substrate and the solder are heated, vaporized moisture, bubbles, etc. rise in the vias and are generated as voids in the solder on the ceramic substrate, which may cause poor connection of electronic components. .
  • the green sheet 1B having the via hole 2B formed by machining does not generate a residue as shown in FIG. That is, by using the green sheet 1B provided with the machined via hole 2B as the outermost layer green sheet on which the mounting electrode is provided, the “green sheet having the laser processed via hole 2A” is formed in a layer other than the layer where the mounting electrode is disposed. Even when “1A” is used, the “via formed in the machined via hole” at the time of reflow soldering prevents “a phenomenon in which voids are generated in the solder”.
  • the “via 6B formed in the machined via hole” does not include voids due to residue, and therefore, substantially all the space in the machined via hole is made of a conductive material. Filled with. Therefore, even if the “via 6A formed in the laser processed via hole” exists on the inner side of the “via 6B formed in the machined via hole” and the moisture or the bubble is included therein, the moisture / bubble is generated. Is prevented by the outermost via 6B. In other words, during reflow soldering, “via 6B formed in a machined via hole” prevents transmission and movement of moisture and bubbles contained in “via 6A formed in a laser processed via hole”. As a result, they are prevented from moving to the solder 9.
  • step (i) is performed. That is, a via hole is formed in at least one of the plurality of green sheets.
  • the via hole 2B of the green sheet 1B provided as the outermost layer of the laminate is formed by machining (“a1” in FIG. P (a)), the other A via hole 2A of the green sheet 1A provided as a layer is formed by laser processing (“a2” in FIG. 13A).
  • the punch press may be of any type as long as it can punch a hole with a pin member (ie, can be punched).
  • NC punch press (Numerical Control) is performed by numerical control. Punch press), or a punch press that punches a plurality of via holes as a die-shaped press.
  • the via hole 2B has a substantially cylindrical shape, that is, the width dimension of the via hole 2B is substantially constant along the direction of the hole thickness.
  • a carbon dioxide (CO 2 ) laser, a YAG laser, an excimer laser, or the like may be used.
  • the laser processing conditions are not particularly limited as long as they are conventionally used for forming via holes in green sheets.
  • the shape of the via hole 2A becomes a truncated cone due to the spread angle of the laser beam, that is, the via hole 2A can have a taper shape in the direction of the hole thickness.
  • step (ii) is performed. That is, the via hole (2A, 2B) is filled with a conductive material. Specifically, as shown in FIG. 13B, conductive paste is supplied to the via holes (2A, 2B) formed in the green sheets 1A, 1B, and the inside of the holes (2A, 2B) is electrically conductive paste. Fill with.
  • various printing methods such as screen printing can be used. It is preferable to dry after filling the conductive paste into the via holes (2A, 2B).
  • necessary wiring layers and internal electrodes may be formed by various printing methods in the same manner. It is preferable to perform a treatment, for example, a drying treatment of 20 to 50 minutes may be performed under a temperature condition of 40 to 80 ° C.).
  • step (iii) is performed. That is, a laminated body is formed by laminating a plurality of green sheets, and the laminated body is subjected to firing to obtain a fired body. Specifically, as shown in FIG. 13C, “green sheet 1A in which via holes are formed by laser irradiation”, “green sheet 1B in which via holes are formed by machining”, and as necessary. A predetermined number of “ceramic sheets 1C without via holes” are stacked and thermocompression bonded to obtain a green sheet laminate 4 ′ (for example, at a temperature of 70 ° C. to 90 ° C. and a pressure of 100 kg / cm 2 to 300 kg / cm 2 .
  • green sheet 1B in which via hole 2B is formed by machining is used as the green sheet positioned on the outermost layer (that is, the green sheet positioned on the uppermost side as shown).
  • the number of stacked green sheets (1A, 1B, 1C) is not particularly limited, and may be, for example, about 3 to 50 in total, preferably about 3 to 15 sheets.
  • the green sheet laminate 4 ′ is preferably subjected to a drying process such as a binder removal step prior to firing.
  • a drying process such as a binder removal step
  • heat treatment may be performed for 20 to 50 hours under a temperature condition of 500 ° C. to 700 ° C.
  • the green sheet laminate 4 ′ is preferably heat-treated at a temperature of 800 ° C. to 1000 ° C. (preferably 850 ° C. to 950 ° C.) for about 0.1 hour to 3 hours.
  • Such heat treatment may be performed by subjecting the green sheet laminate 4 ′ to a firing furnace such as a mesh belt furnace.
  • the firing method as described above is disclosed in Japanese Patent Laid-Open No. 5-102666, and should be referred to as necessary.
  • the ceramic substrate 100 provided with the fired body 4 and vias 6 (6A, 6B) therein can be obtained.
  • step (I) is carried out. That is, the mounting electrode is formed on the fired body so as to be in contact with the via of the obtained ceramic substrate.
  • the electrode 7 is formed by providing a conductive paste as an electrode material on the fired body 4 by screen printing or the like.
  • the conductive paste for forming the mounting electrode 7 may be an Ag paste, for example.
  • step (II) is performed. That is, solder is provided on the mounting electrode, and an electronic component is disposed on the solder.
  • a solder ball 9 may be provided on the mounting electrode 7 and a semiconductor IC may be provided as the electronic component 10 on the solder ball 9.
  • step (III) is performed. That is, a reflow soldering process is performed. Specifically, as shown in FIG. 14E, the ceramic substrate 100, the electrical component 10, and the solder balls 9 and the electrodes 7 interposed therebetween are integrally subjected to a heat treatment. As a result, the ceramic substrate 100 and the electrical component 10 are electrically connected to each other via the solder material, and the electrical circuit module 200 is obtained.
  • the “via 6B formed in the machined via hole” is changed from the transmission of moisture and bubbles caused by the “via 6A formed in the laser processed via hole”. Since the movement is prevented, such moisture and bubbles do not move to the solder ball 9, and as a result, generation of voids in the solder is prevented.
  • a “green sheet having a via hole formed by laser light irradiation” can be used for a layer other than the layer for forming the electrode.
  • the via hole formation time (process tact time) by laser irradiation is about one-sixth of the via hole formation time (process tact time) by machining (for example, NC punch press). it can. That is, according to the present invention, the manufacturing yield of the ceramic substrate itself and, consequently, the process yield in the electrical circuit module manufacturing using the ceramic substrate can be improved without substantially adversely affecting the tact time in the ceramic substrate manufacturing. As a result, the ceramic substrate and the electric circuit module using the ceramic substrate can be provided to the market at a low cost).
  • the via located in the outermost layer on which the mounting electrode is provided may be a via formed by filling a machining hole with a conductive material. Accordingly, as shown in FIG. 15, not only the via hole in the uppermost green sheet provided with the mounting electrode 7 is formed by machining, but also the via hole in the lowermost green sheet provided with the mounting electrode 7 is machined. May be formed.
  • the vias located in both the uppermost layer and the lowermost layer may be “vias formed by filling a machining hole with a conductive material”. Even in such an embodiment, the above-described effects of the present invention are similarly obtained.
  • This aspect is useful in that electronic components can be mounted on both sides of the substrate.
  • FIG. 16A shows the overall shape of vias and via holes in a single-sided mounting board
  • FIG. 16B shows the overall shape of vias and via holes in a double-sided mounting board.
  • at least the outermost green sheet of the green sheet laminate need only be formed by machining.
  • At least one green sheet via hole corresponding to the lower layer of the outermost surface green sheet may also be formed by machining. Even in such a case, the above-described effects of the present invention are similarly obtained. ⁇ In view of the essential features of the present invention, not only the mode of mounting through electrodes, but also the mode of mounting electronic components directly on a ceramic substrate with solder without using such electrodes, The effects of the present invention are also exhibited.
  • the present invention is not only effective in the “solder reflow method”, but can also be effective in other mounting methods resulting from heat treatment. .
  • GGI Gold-to-Gold
  • First embodiment At least one sheet is a fired body (or sintered body) formed by firing (or sintering) a laminate of a plurality of green sheets having via holes, and the via hole is filled with a conductive material.
  • Second aspect The ceramic substrate according to the first aspect, wherein the hole width dimension of the via hole formed by machining is constant along the hole thickness direction.
  • Third aspect The ceramic substrate according to the first or second aspect, wherein the “via hole in the green sheet other than the outermost green sheet” is a via hole formed by laser processing.
  • Fourth aspect The ceramic substrate according to the third aspect, wherein the hole width dimension of the via hole formed by laser processing is not constant along the hole thickness direction but gradually decreases or gradually increases. .
  • Fifth aspect The ceramic substrate according to any one of the first to fourth aspects, further comprising an electrode provided on the fired body so as to be in contact with the via.
  • An electric circuit module comprising the ceramic substrate according to any one of the first to fourth aspects, An electrical circuit module (electronic circuit module) comprising a mounting electrode provided on a fired body so as to be in contact with a via, and an electronic component mounted on the mounting electrode.
  • a method for producing a ceramic substrate comprising: (I) forming a via hole in at least one of the plurality of green sheets; (Ii) filling a via hole with a conductive material, and (iii) forming a laminate by laminating a plurality of green sheets, and subjecting the laminate to firing to obtain a fired body.
  • a method of manufacturing a ceramic substrate wherein via holes are formed by machining in the “outermost layer green sheet used as an outermost layer of a green sheet laminate and provided with a mounting electrode”.
  • Eighth aspect A method for producing a ceramic substrate according to the seventh aspect, wherein a punch press is performed as the machining.
  • Ninth aspect In the seventh aspect or the eighth aspect, in the step (i), the via hole in the “green sheet other than the outermost layer green sheet” is formed by laser processing.
  • Tenth aspect A method of manufacturing an electric circuit module (electronic circuit module) using the ceramic substrate according to any one of the first to fourth aspects, (I) forming a mounting electrode on the fired body so as to be in contact with the via of the ceramic substrate; (II) a step of providing solder on the mounting electrode and arranging electronic components on the solder; and (III) reflow soldering the “ceramic substrate, electrical component and solder interposed between them and mounting electrode” A method of manufacturing an electric circuit module (electronic circuit module) comprising a step of attaching.
  • the ceramic substrate according to the present invention is suitably used as an RF module of a mobile device, a power LED substrate using heat dissipation, or an LED substrate for a liquid crystal backlight, and an electronic component mounted with high density. It is also suitably used as a substrate for equipment.
  • the present invention provides a void inside the solder even when the electronic component is obtained by mounting electronic components on a ceramic substrate by solder reflow due to the machined via hole in the outermost green sheet of the laminate. Since generation

Abstract

The disclosed ceramic substrate (100) comprises: a fired body (4) formed by firing a stacked body of a plurality of green sheets of which at least one has a via hole; and vias (6) (6A, 6B) formed by filling the via hole with a conductive material. Specifically, regarding the disclosed ceramic substrate (100), in the green sheet stacked body, a via hole (2B), which is in the green sheet (1B) that is the outermost layer to which a mounting electrode (7) is provided, forms a via hole formed by machining.

Description

セラミック基板および電気回路モジュールならびにそれらの製造方法Ceramic substrate, electric circuit module, and manufacturing method thereof
　本発明は、セラミック基板およびそれを用いた電気回路モジュール、ならびにそれらの製造方法に関する。より詳細には、本発明は、グリーンシートの積層焼成体から成るセラミック基板およびそれを用いた電気回路モジュールに関すると共に、かかるセラミック基板および電気回路モジュールの製造方法にも関する。 The present invention relates to a ceramic substrate, an electric circuit module using the ceramic substrate, and a manufacturing method thereof. More specifically, the present invention relates to a ceramic substrate composed of a laminated fired body of green sheets and an electric circuit module using the same, and also relates to a method of manufacturing the ceramic substrate and the electric circuit module.
　セラミック基板は、耐熱性・耐湿性に優れており、また、高周波回路において良好な周波数特性を有し得る。従って、セラミック基板は、モバイル機器のＲＦ（Ｒａｄｉｏ　Ｆｒｅｑｕｅｎｃｙ）モジュールや放熱性を利用したパワーＬＥＤ（Ｌｉｇｈｔ　Ｅｍｉｔｔｉｎｇ　Ｄｉｏｄｅ：発光ダイオード）用の基板、および、液晶のバックライト向けＬＥＤ用の基板として用いられると共に、電子部品が高密度実装された電子機器の基板としても用いられる。 The ceramic substrate is excellent in heat resistance and moisture resistance, and may have good frequency characteristics in a high frequency circuit. Accordingly, the ceramic substrate is used as an RF (Radio Frequency) module of a mobile device, a substrate for a power LED (Light Emitting Diode) utilizing heat dissipation, and a substrate for an LED for a liquid crystal backlight. It is also used as a substrate for electronic equipment on which electronic components are mounted with high density.
　このようなセラミック基板は、複数のグリーンシートを積層して焼成することによって得ることができる。セラミック基板にはビアが設けられるが、かかるビアは、積層体を成すグリーンシートに形成されたビアホールに導電ペーストが充填されることを通じて形成される。 Such a ceramic substrate can be obtained by laminating and firing a plurality of green sheets. The ceramic substrate is provided with a via, and the via is formed by filling a via hole formed in a green sheet forming a laminated body with a conductive paste.
　ここで、従前のセラミック基板においては、ビアホールがレーザを用いて形成された穴部を成している。つまり、従前のビアホールは、グリーンシートに対してレーザ光を照射し、その際に生じる熱によってグリーンシート成分を溶融及び焼失させることによって形成されている（国際公開第２００８／１１１４０８号公報参照）。特に昨今では、電子機器の小型化・高性能化に伴ってビアが高密度化しており、非接触で微細に高速加工できることから、ビアホールの形成にはレーザ光を用いることが主流となっている。 Here, in the conventional ceramic substrate, the via hole is a hole formed using a laser. That is, the conventional via hole is formed by irradiating the green sheet with laser light and melting and burning the green sheet component by the heat generated at that time (see International Publication No. 2008/111408). In recent years, vias have become denser with the downsizing and higher performance of electronic equipment and can be processed finely at high speed without contact, so the use of laser light is the mainstream for forming via holes. .
　上述のようにグリーンシートのビアホール形成においてはレーザ光を用いることが主流となっているが、本願発明者らは、かかるレーザ光に起因したある特有の現象を見出した。具体的には、レーザ光照射によってビアホールを形成する際、グリーンシート中の“ガラス成分による溶融残留物”および／または“有機バインダ成分による燃焼残留物”が発生し、それら残留物の量が多くなると、その後の製造工程においてビア部とセラミック部の間に空隙が生じ、その結果、水分あるいは気泡が空隙に浸入してしまう現象を見出した（“残留物”については図１を参照のこと）。そして、かかる現象に起因して、はんだリフローでセラミック基板に電子部品を実装する際には、半田中にボイドが発生して電子部品の接続不良が引き起こされることを結果として見出した（半田中にボイドが発生して半田が爆発・飛散する現象については図２を参照のこと）。それゆえ、高密度実装された電子機器用基板においては、その基板上のビアホールが“高密度”となるので、上記ボイドに起因した電子部品の接続不良がより顕著になることが懸念される。 As described above, the use of laser light is the mainstream in the formation of via holes in green sheets, but the inventors of the present application have found a specific phenomenon caused by such laser light. Specifically, when forming a via hole by laser light irradiation, “melting residue due to glass component” and / or “combustion residue due to organic binder component” occurs in the green sheet, and the amount of such residue is large. Then, in the subsequent manufacturing process, a void was formed between the via portion and the ceramic portion, and as a result, a phenomenon was found in which moisture or air bubbles entered the void (see FIG. 1 for “residue”). . As a result, it has been found that when electronic components are mounted on a ceramic substrate by solder reflow due to such a phenomenon, voids are generated in the solder, resulting in poor connection of the electronic components (in the solder) (See Fig. 2 for the phenomenon of voids and solder explosion and scattering). Therefore, in an electronic device substrate mounted with high density, the via holes on the substrate become “high density”, and there is a concern that the connection failure of the electronic component due to the void becomes more conspicuous.
　つまり、従来技術のセラミック基板（特に高密度実装に適したセラミック基板）では、ビアホール形成時の残留物に起因して電子部品の接続不良が引き起こされ、ひいては、電気回路モジュールの製造工程における歩留りが低下してしまう。 In other words, conventional ceramic substrates (especially ceramic substrates suitable for high-density mounting) cause poor connection of electronic components due to residues at the time of forming via holes, and consequently yield in the manufacturing process of electric circuit modules. It will decline.
　本発明はかかる事情に鑑みて為されたものである。つまり、本発明の主たる目的は、上記接続不良の問題に好適に対処できるセラミック基板を提供することであり、それによって、セラミック基板を備えた電気回路モジュールの製造時における歩留りの向上を図ることである。 The present invention has been made in view of such circumstances. That is, the main object of the present invention is to provide a ceramic substrate that can suitably cope with the problem of the above-mentioned connection failure, thereby improving the yield at the time of manufacturing an electric circuit module including the ceramic substrate. is there.
　上記課題を解決するため、本発明では、
　少なくとも１枚にはビアホールを有する複数枚のグリーンシートの積層体の焼成によって形成された焼成体、および
　ビアホールに導電性材料が充填されることによって形成されたビア
を有して成り、
　上記の積層体につき、実装用電極が設けられる最表層のグリーンシートにおけるビアホールが“機械加工により形成されたビアホール”となっているセラミック基板が提供される。 In order to solve the above problems, in the present invention,
At least one has a fired body formed by firing a laminate of a plurality of green sheets having via holes, and a via formed by filling a via hole with a conductive material,
A ceramic substrate is provided in which the via hole in the outermost green sheet on which the mounting electrode is provided is a “via hole formed by machining” with respect to the laminate.
　本発明に係るセラミック基板の特徴の１つは、焼成体を形成する積層体の複数枚のグリーンシートのうち、実装用電極が設けられる最表層のグリーンシートにおけるビアホールが機械加工で形成されていることである（以下においては、機械加工で形成されたビアホールを“機械加工ビアホール”ないしは“機械加工ホール”とも称す）。換言すれば、本発明のセラミック基板においては、最表層に位置するビアが“機械加工ホールに導電性材料を充填して形成されたビア”となっている。 One of the features of the ceramic substrate according to the present invention is that a via hole is formed by machining in the outermost green sheet on which the mounting electrode is provided among the plurality of green sheets of the laminate forming the fired body. (In the following, via holes formed by machining are also referred to as “machined via holes” or “machined holes”). In other words, in the ceramic substrate of the present invention, the via located in the outermost layer is “a via formed by filling a machining hole with a conductive material”.
　本明細書で用いる「最表層のグリーンシート」とは、複数枚のグリーンシートを相互に積み重ねることによって得られた積層体において、最も外側に位置するグリーンシートのことを実質的に意味している。例えば、図３に示す態様でいえば、最上層および／または最下層の相当するグリーンシートが“最表層”に相当する。 As used herein, the “outermost layer green sheet” substantially means the outermost green sheet in a laminate obtained by stacking a plurality of green sheets. . For example, in the embodiment shown in FIG. 3, the green sheet corresponding to the uppermost layer and / or the lowermost layer corresponds to the “outermost layer”.
　ある好適な態様では、本発明のセラミック基板は、最表層に位置するビアと接するように焼成体上に設けられた電極を更に有して成る。 In a preferred aspect, the ceramic substrate of the present invention further includes an electrode provided on the fired body so as to be in contact with the via located in the outermost layer.
　別のある好適な態様において、機械加工により形成されたビアホールは、その厚み方向に沿って幅寸法が一定している。つまり、機械加工ホールの断面（ビアホールの厚み方向に沿って平行な面によって切り取ったホール断面）は、矩形状または正方形状を有している。これは、機械加工ホールに導電性材料を充填して形成されたビアの幅寸法が、その厚み方向に沿って一定していることを意味しており、それゆえ、かかるビアの断面（ビアの厚み方向に沿って平行な面で切り取ったビア断面）も、矩形状または正方形状を有していることを意味している。 In another preferred aspect, the via hole formed by machining has a constant width dimension along the thickness direction. That is, the cross section of the machined hole (hole cross section cut by a plane parallel to the thickness direction of the via hole) has a rectangular shape or a square shape. This means that the width dimension of a via formed by filling a machined hole with a conductive material is constant along the thickness direction, and therefore the cross-section of such via (via The via cross-section cut by a plane parallel to the thickness direction also means having a rectangular shape or a square shape.
　別のある好適な態様では、最表層のグリーンシート以外のグリーンシートにおけるビアホールが、レーザ加工により形成されたビアホールとなっている（以下においては、レーザで形成されたビアホールを“レーザ加工ビアホール”ないしは“レーザ加工ホール”とも称す）。つまり、最上層および／または最下層の相当するグリーンシート以外のグリーンシート（即ち、積層体内部に位置するグリーンシート）のビアホールが、レーザ加工により形成されている。例えば、最上層に相当するグリーンシートのビアホールのみが機械加工ホールになっており、それ以外のビアホールは全てレーザ加工ホールとなっていてよい。 In another preferred embodiment, the via hole in the green sheet other than the outermost layer green sheet is a via hole formed by laser processing (hereinafter referred to as “laser processed via hole” or Also called “laser machining hole”. That is, via holes of green sheets other than the corresponding green sheets of the uppermost layer and / or the lowermost layer (that is, green sheets located inside the laminate) are formed by laser processing. For example, only the via hole of the green sheet corresponding to the uppermost layer may be a machined hole, and all other via holes may be laser processed holes.
　レーザ加工で形成されたビアホールは、その厚み方向にテーパ形状を有し得る。つまり、レーザ加工ビアホールの断面（ビアホールの厚み方向に沿って平行な面によって切り取ったホール断面）は、台形状を有している。これは、レーザ加工ビアホールに形成されたビアが、その厚み方向にテーパ形状を有していることを意味しており、それゆえ、かかるビアの断面（ビアの厚み方向に沿って平行な面で切り取ったビア断面）も、台形状を有していることを意味している。 The via hole formed by laser processing can have a taper shape in the thickness direction. That is, the cross section of the laser processed via hole (the hole cross section cut by a plane parallel to the thickness direction of the via hole) has a trapezoidal shape. This means that the via formed in the laser processed via hole has a taper shape in the thickness direction, and therefore, the cross-section of the via (in a plane parallel to the via thickness direction). The cut via cross-section) also has a trapezoidal shape.
　本発明では、上述のセラミック基板を用いた電気回路モジュールも提供される。かかる電気回路モジュールは、
　セラミック基板のビアと接するようにして焼成体上に設けられた実装用電極、および
　かかる実装用電極上に半田を介して実装された電子部品
を有して成る。
つまり、本発明の電気回路モジュールは、
　少なくとも１枚にはビアホールを有する複数枚のグリーンシートの積層体の焼成により形成された焼成体、
　ビアホールに導電性材料が充填されることにより形成されたビア、
　ビアと接するように焼成体上に設けられた電極、および
　電極上に実装された電子部品（特に、電極上に半田を介して実装された電子部品）
を有して成り、
　上記の積層体につき、電極が設けられる最表層に相当するグリーンシートのビアホールが、機械加工により形成されたビアホールとなっている。 The present invention also provides an electric circuit module using the above-described ceramic substrate. Such an electric circuit module is
A mounting electrode provided on the fired body so as to be in contact with the via of the ceramic substrate, and an electronic component mounted on the mounting electrode via solder.
That is, the electric circuit module of the present invention is
A fired body formed by firing a laminate of a plurality of green sheets having via holes in at least one sheet;
A via formed by filling a via hole with a conductive material,
Electrodes provided on the fired body so as to be in contact with the vias, and electronic components mounted on the electrodes (particularly electronic components mounted on the electrodes via solder)
Comprising
In the laminate, the via hole of the green sheet corresponding to the outermost layer on which the electrode is provided is a via hole formed by machining.
　かかる本発明に係る電気回路モジュールの特徴の１つは、セラミック基板の焼成体を形成する積層体のグリーンシートのうち、実装用電極が設けられる最表層のグリーンシートにおけるビアホールが機械加工によって形成されていることである。 One of the features of the electric circuit module according to the present invention is that a via hole is formed by machining in the outermost green sheet on which the mounting electrodes are provided, among the green sheets of the laminate forming the fired body of the ceramic substrate. It is that.
　本発明では、上述のセラミック基板を製造するための方法も提供される。かかる本発明のセラミック基板の製造方法は、
　（ｉ）複数のグリーンシートの少なくとも１枚にビアホールを形成する工程、
　（ｉｉ）ビアホールに導電性材料を充填する工程、および
　（ｉｉｉ）複数のグリーンシートを積層することによって積層体を形成し、かかる積層体を焼成に付して焼成体を得る工程
を含んで成り、
　工程（ｉ）では、「積層体の最表層として用いられ、かつ、実装用電極が設けられるグリーンシート」のビアホールを機械加工によって形成する。 The present invention also provides a method for manufacturing the above-described ceramic substrate. Such a method for producing a ceramic substrate of the present invention comprises:
(I) forming a via hole in at least one of the plurality of green sheets;
(Ii) filling a via hole with a conductive material, and (iii) forming a laminate by laminating a plurality of green sheets, and subjecting the laminate to firing to obtain a fired body. ,
In step (i), a via hole of “a green sheet that is used as the outermost layer of the laminate and is provided with a mounting electrode” is formed by machining.
　かかる本発明に係るセラミック基板の製造方法の特徴の１つは、積層体を構成する複数枚のグリーンシートのうち“実装用電極が設けられる最表層グリーンシート”に対して機械加工でビアホールを形成することである。換言すれば、実装用電極は、機械加工によって形成されたビアホール（より具体的には、機械加工ホールに導電性材料を充填して形成されたビア）上に形成されることになる。 One of the features of the method for manufacturing a ceramic substrate according to the present invention is that a via hole is formed by machining on the “outermost surface green sheet on which mounting electrodes are provided” among a plurality of green sheets constituting the laminate. It is to be. In other words, the mounting electrode is formed on a via hole formed by machining (more specifically, a via formed by filling the machining hole with a conductive material).
　かかる製造方法のある好適な態様では、機械加工としてパンチプレスを実施する。つまり、パンチプレス加工を実施することによって、積層体の最表層グリーンシートのビアホールを形成する。 In a preferred aspect of the manufacturing method, a punch press is performed as machining. That is, the via hole of the outermost layer green sheet of the laminate is formed by performing punch press processing.
　別のある好適な態様では、積層体の最表層として設けられるグリーンシート以外のグリーンシートにおけるビアホールはレーザ加工によって形成する。つまり、最上層および／または最下層の相当するグリーンシート以外のグリーンシート（積層体内部に位置するグリーンシート）のビアホールをレーザ加工によって形成する。 In another preferred embodiment, the via hole in the green sheet other than the green sheet provided as the outermost layer of the laminate is formed by laser processing. That is, via holes of green sheets other than the corresponding green sheets in the uppermost layer and / or the lowermost layer (green sheets located inside the laminate) are formed by laser processing.
　本発明では、上述の製造方法で得られたセラミック基板を利用した電気回路モジュールの製造方法も提供される。かかる本発明の電気回路モジュールの製造方法は、
　（Ｉ）セラミック基板のビアと接するようにセラミック焼成体上に実装用電極を形成する工程、
　（ＩＩ）セラミック基板の電極上に半田を設けて、かかる半田の上に電子部品を配置する工程、および
　（ＩＩＩ）セラミック基板、電気部品およびそれらの間に介在する半田を一体的にリフローはんだ付けに付す工程（即ち、セラミック基板、電子部品及びそれらの間に介在する半田を一体的に熱処理に付す工程）
を含んで成る。 In this invention, the manufacturing method of the electrical circuit module using the ceramic substrate obtained by the above-mentioned manufacturing method is also provided. Such a method of manufacturing an electric circuit module of the present invention includes:
(I) forming a mounting electrode on the ceramic fired body so as to be in contact with the via of the ceramic substrate;
(II) a step of providing solder on the electrodes of the ceramic substrate, and placing electronic components on the solder; and (III) reflow soldering integrally with the ceramic substrate, the electrical components and the solder interposed therebetween. (Ie, a process of subjecting the ceramic substrate, the electronic component, and the solder interposed therebetween to heat treatment)
Comprising.
　換言すれば、本発明の電気回路モジュールの製造方法は、
　（ｉ）複数のグリーンシートの少なくとも１枚にビアホールを形成する工程、
　（ｉｉ）ビアホールに導電性材料を充填する工程、および
　（ｉｉｉ）複数のグリーンシートを積層することによって積層体を形成した後、かかる積層体を焼成に付して焼成体を得る工程
を含んで成ると共に、
　（Ｉ）ビアと電気的に接続されるように焼成体上に電極を形成する工程
　（ＩＩ）電極上に半田を設けた後、かかる半田の上に電子部品を配置する工程、および
　（ＩＩＩ）リフローはんだ付けを実施すべく、セラミック基板、電子部品及びそれらの間に介在する半田を一体的に熱処理に付す工程
を更に含んで成り、
　工程（ｉ）では、積層体の最表層として設けられるグリーンシートのビアホールを機械加工によって形成し、また、工程（Ｉ）では、機械加工によって形成されたビアホール上に電極を形成する（より具体的には、“機械加工ホールに導電性材料を充填して形成されたビア”と接するように電極を形成する）。 In other words, the manufacturing method of the electric circuit module of the present invention is:
(I) forming a via hole in at least one of the plurality of green sheets;
(Ii) filling a via hole with a conductive material, and (iii) forming a laminated body by laminating a plurality of green sheets, and then subjecting the laminated body to firing to obtain a fired body. As
(I) A step of forming an electrode on the fired body so as to be electrically connected to the via (II) A step of placing an electronic component on the solder after providing the solder on the electrode, and (III) In order to perform reflow soldering, the method further includes a step of subjecting the ceramic substrate, the electronic component, and the solder interposed therebetween to a heat treatment,
In step (i), a via hole of a green sheet provided as the outermost layer of the laminate is formed by machining, and in step (I), an electrode is formed on the via hole formed by machining (more specifically, The electrode is formed so as to be in contact with “a via formed by filling a machining hole with a conductive material”).
　かかる本発明に係る電気回路モジュールの製造方法の特徴の１つは、セラミック基板を形成するための積層体を構成する複数枚のグリーンシートのうち“実装用電極が設けられる最表層のグリーンシート”に対して機械加工によりビアホールを形成し、その機械加工ビアホールのビア上に半田を配してリフローはんだ付けを行うことである。 One of the features of the method of manufacturing an electric circuit module according to the present invention is that “the outermost green sheet on which mounting electrodes are provided” among a plurality of green sheets constituting a laminate for forming a ceramic substrate. On the other hand, a via hole is formed by machining, and solder is disposed on the via of the machined via hole to perform reflow soldering.
　本発明に従えば、最表層グリーンシートにおける機械加工ビアホールに起因して、はんだリフローで電子部品をセラミック基板上に実装する際、“半田内部にて発生するボイド”を回避することができる。 According to the present invention, it is possible to avoid “a void generated in the solder” when the electronic component is mounted on the ceramic substrate by solder reflow due to the machined via hole in the outermost layer green sheet.
　より具体的には、セラミック基板の製造に際して“複数枚のグリーンシートから成る積層体”の最表層グリーンシートにおけるビアホール（特に、実装用電極と接続されるビアのために形成されるビアホール）が機械加工によって得られるので、熱に起因する「ビアホール形成時の残留物発生」が回避されることになり、結果として、“機械加工ビアホール内の全ての空間が導電性材料によって十分に充填されて成るビア”が得られることになる。これにより、“はんだリフロー工程にて半田内部に発生し得るボイド”を効果的に防止することができ、その結果、セラミック基板に電子部品を実装して電気回路モジュールを製造する際の歩留まりが向上する。 More specifically, when manufacturing a ceramic substrate, a via hole (especially a via hole formed for a via connected to a mounting electrode) in the outermost green sheet of a “laminated body composed of a plurality of green sheets” is a machine. Since it is obtained by machining, “residue generation during via hole formation” due to heat is avoided, and as a result, “all the spaces in the machined via hole are sufficiently filled with the conductive material. A “via” will be obtained. This effectively prevents “voids that can occur inside the solder during the solder reflow process” and, as a result, improves the yield when manufacturing electronic circuit modules by mounting electronic components on a ceramic substrate. To do.
　特に本発明では、積層体を構成する複数のグリーンシートの全てのビアホール形成に際して機械加工を施すのではなく、あくまでも最表層に位置するグリーンシートのビアホールを機械加工で形成するにすぎない（つまり、最表層以外のグリーンシートのビアホールは高速加工可能なレーザによって形成してよい）。従って、本発明は、セラミック基板製造におけるタクトタイムに実質的な悪影響を与えることなく、セラミック基板の製造、ひいては、それを用いた電気回路モジュールの製造における工程歩留りの向上を図ることができる点で非常に有益である。 In particular, in the present invention, machining is not performed when all the via holes of the plurality of green sheets constituting the laminated body are formed, but the via holes of the green sheet located in the outermost layer are merely formed by machining (that is, The via hole of the green sheet other than the outermost layer may be formed by a laser capable of high-speed processing). Therefore, the present invention can improve the process yield in the production of a ceramic substrate and, in the production of an electric circuit module using the ceramic substrate, without substantially adversely affecting the tact time in the production of the ceramic substrate. Very beneficial.
　図１（Ｆｉｇ．１）は、グリーンシートにレーザ光を照射してビアホールを形成する際に生じた残留物（溶融残留物・燃焼残留物）を示した写真図である。
　図２（Ｆｉｇ．２）は、半田中にボイドが発生して半田が爆発・飛散する現象を示した写真図である。
　図３（Ｆｉｇ．３）は、“最表層グリーンシート”を説明するための積層体の模式的断面図である。
　図４（Ｆｉｇ．４）は、本発明のセラミック基板の態様を模式的に示した斜視図である。
　図５（Ｆｉｇ．５）は、本発明のセラミック基板の態様を模式的に示した断面図である。
　図６（Ｆｉｇ．６）は、レーザ加工ビアホールの態様を示す模式図である（図６（ａ）：平面図、図６（ｂ）：図６（ａ）のａ−ａ線で切り取った断面図）。
　図７（Ｆｉｇ．７）は、機械加工ビアホールの態様を示す模式図である（図７（ａ）：平面図、図７（ｂ）：図７（ａ）のｂ−ｂ線で切り取った断面図）
　図８（Ｆｉｇ．８）は、ビアホール寸法を説明するためのグリーンシートの模式的断面図である。
　図９（Ｆｉｇ．９）は、グリーンシート積層体の態様を模式的に示した斜視展開図である。
　図１０（Ｆｉｇ．１０）は、本発明のセラミック基板の態様を模式的に示した断面図である。
　図１１（Ｆｉｇ．１１）は、本発明の電気回路モジュールの態様を模式的に示した断面図である。
　図１２（Ｆｉｇ．１２）は、グリーンシートに形成されたビアホールの形態を示した写真図である（図１２（ａ）：レーザ加工ビアホール、図１２（ｂ）：機械加工ビアホール）
　図１３（Ｆｉｇ．１３）は、本発明のセラミック基板の製造方法の態様を模式的に示した斜視図および断面図である。
　図１４（Ｆｉｇ．１４）は、本発明の電気回路モジュールの製造方法の態様を模式的に示した断面図である。
　図１５（Ｆｉｇ．１５）は、本発明のセラミック基板（両面実装用の基板）の態様を模式的に示した断面図である。
　図１６（Ｆｉｇ．１６）は、本発明のセラミック基板の典型的なビア／ビアホールの全体形状のみを模式的に示した斜視図である（図１６（ａ）：片面実装用基板におけるビア・ビアホールの全体形状、図１６（ｂ）：両面実装用基板におけるビア・ビアホールの全体形状）。
　図１７（Ｆｉｇ．１７）は、本発明の効果確認試験の結果を示す写真図である（図１７（ａ）：比較例１、図１７（ｂ）：実施例１）。 1 (FIG. 1) is a photographic diagram showing residues (melted residue / combustion residue) generated when a via hole is formed by irradiating a green sheet with laser light.
FIG. 2 (FIG. 2) is a photograph showing a phenomenon in which voids are generated in the solder and the solder explodes and scatters.
FIG. 3 (FIG. 3) is a schematic cross-sectional view of a laminate for explaining the “outermost layer green sheet”.
4 (FIG. 4) is a perspective view schematically showing an aspect of the ceramic substrate of the present invention.
5 (FIG. 5) is a cross-sectional view schematically showing an aspect of the ceramic substrate of the present invention.
Fig. 6 (Fig. 6) is a schematic view showing a mode of a laser processed via hole (Fig. 6 (a): plan view, Fig. 6 (b): cross section taken along line aa in Fig. 6 (a)). Figure).
Fig. 7 (Fig. 7) is a schematic diagram showing a mode of a machined via hole (Fig. 7 (a): plan view, Fig. 7 (b): cross section taken along line bb in Fig. 7 (a)). (Figure)
8 (FIG. 8) is a schematic cross-sectional view of a green sheet for explaining the via hole dimensions.
FIG. 9 (FIG. 9) is a perspective developed view schematically showing an aspect of the green sheet laminate.
10 (FIG. 10) is a cross-sectional view schematically showing an embodiment of the ceramic substrate of the present invention.
11 (FIG. 11) is a cross-sectional view schematically showing an aspect of the electric circuit module of the present invention.
12 (FIG. 12) is a photograph showing the form of via holes formed in the green sheet (FIG. 12 (a): laser processed via hole, FIG. 12 (b): machined via hole).
13 (FIG. 13) is a perspective view and a cross-sectional view schematically showing an aspect of the method for producing a ceramic substrate of the present invention.
14 (FIG. 14) is a cross-sectional view schematically showing an aspect of the method for manufacturing the electric circuit module of the present invention.
15 (FIG. 15) is a cross-sectional view schematically showing an aspect of the ceramic substrate (substrate for double-sided mounting) of the present invention.
16 (FIG. 16) is a perspective view schematically showing only the entire shape of a typical via / via hole of the ceramic substrate of the present invention (FIG. 16 (a): via / via hole in a single-sided mounting substrate. FIG. 16B: Overall shape of vias and via holes in a double-sided mounting board).
Fig. 17 (Fig. 17) is a photograph showing the results of the effect confirmation test of the present invention (Fig. 17 (a): Comparative Example 1, Fig. 17 (b): Example 1).
図面中、参照番号は次の要素を意味する：
　１　グリーンシート
　１Ａ　レーザ加工ビアホールを備えたグリーンシート
　１Ｂ　機械加工ビアホールを備えたグリーンシート
　１Ｃ　ビアホールを備えていないグリーンシート
　２　ビアホール
　２Ａ　レーザ加工ビアホール
　２Ｂ　機械加工ビアホール
　１００　セラミック基板
　４　焼成体（グリーンシート積層体の焼成により得られた焼成体）
　４’　グリーンシート積層体
　５　導電性材料（導体ペースト）
　６　ビア
　６Ａ　レーザ加工ビアホールに形成されたビア
　６Ｂ　機械加工ビアホールに形成されたビア
　７　電極（実装用電極）
　８　電気回路モジュール
　９　半田（例えば半田ボール）
　１０　電子部品
　３０　機械加工具
　４０　レーザ光
　５０　焼成炉
　１００，１００’　セラミック基板
　２００　電気回路モジュール In the drawings, reference numbers refer to the following elements:
DESCRIPTION OF SYMBOLS 1 Green sheet 1A Green sheet | seat provided with laser processing via hole 1B Green sheet | seat provided with machining via hole 1C Green sheet | seat without via hole 2 Via hole 2A Laser processing via hole 2B Machining via hole 100 Ceramic substrate 4 Fired body (green sheet laminated body) Fired body obtained by firing)
4 'Green sheet laminate 5 Conductive material (conductor paste)
6 via 6A via formed in laser processed via hole 6B via formed in machined via hole 7 electrode (mounting electrode)
8 Electric circuit module 9 Solder (eg solder ball)
DESCRIPTION OF SYMBOLS 10 Electronic component 30 Machine tool 40 Laser beam 50 Baking furnace 100,100 'Ceramic substrate 200 Electric circuit module
　以下、図面を参照しながら、本発明の実施の形態を説明する。図面においては、説明の簡略化のため、実質的に同一の機能を有する構成要素を同一の参照番号で示している。また、各図における寸法関係（長さ、幅、厚さなど）は実際の寸法関係を反映するものではない。更に、本明細書で説明される“上下方向”については、グリーンシートが積層される方向を“上方向”／“上側”とし、それに対向する逆方向を“下方向”／“下側”としており、便宜上、図中における上下方向に対応している。 Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings, components having substantially the same function are denoted by the same reference numerals for the sake of simplicity. Further, the dimensional relationship (length, width, thickness, etc.) in each figure does not reflect the actual dimensional relationship. Furthermore, regarding the “up and down direction” described in this specification, the direction in which the green sheets are stacked is “upward” / “upper”, and the opposite direction opposite to it is “downward” / “lower”. For convenience, it corresponds to the vertical direction in the figure.
（本発明のセラミック基板）
　本発明のセラミック基板１００は、図４および図５に示すように、焼成体４およびその焼成体内に形成されたビア６を有して成る。かかるセラミック基板の焼成体４は、少なくとも１枚にはビアホールを有する複数枚のグリーンシートの積層体が焼成されることによって形成されている。また、焼成体４に設けられたビア６は、グリーンシートのビアホール２（２Ａ，２Ｂ）に導電性材料が充填されることによって形成されている。 (Ceramic substrate of the present invention)
As shown in FIGS. 4 and 5, the ceramic substrate 100 of the present invention includes a fired body 4 and vias 6 formed in the fired body. The fired body 4 of the ceramic substrate is formed by firing a laminate of a plurality of green sheets each having a via hole. The via 6 provided in the fired body 4 is formed by filling the via hole 2 (2A, 2B) of the green sheet with a conductive material.
　本発明のセラミック基板１００では、複数のグリーンシートが積層される際、実装用電極７を形成する側に「機械加工によりビアホール２Ｂを形成したグリーンシート１Ｂ」が用いられる。その他のシート部分は「レーザ光を照射することによりビアホール２Ａを形成したグリーンシート１Ａ」が用いられ、また必要に応じて「ビアホールを有しないセラミックシート１Ｃ」も用いられる。つまり、本発明のセラミック基板１００では、焼成体４を形成する積層体の複数枚のグリーンシート（１Ａ，１Ｂ，１Ｃ，・・・）のうち、実装電極７が設けられる最表層グリーンシート（１Ｂ）におけるビアホール（２Ｂ）が機械加工により形成された穴部を成している。別の表現をすれば、本願発明のセラミック基板１００においては、グリーンシート積層体を構成する複数枚のグリーンシートが「機械加工ビアホール２Ｂを備えた最表層グリーンシート１Ｂ」と「レーザ加工ビアホール２Ａを備えた内部グリーンシート１Ａ」との組合せを少なくとも有して成る。 In the ceramic substrate 100 of the present invention, when a plurality of green sheets are stacked, the “green sheet 1B in which via holes 2B are formed by machining” is used on the side on which the mounting electrodes 7 are formed. As the other sheet portions, “green sheet 1A in which via hole 2A is formed by irradiating laser light” is used, and “ceramic sheet 1C having no via hole” is also used as necessary. That is, in the ceramic substrate 100 of the present invention, among the plurality of green sheets (1A, 1B, 1C,...) Of the laminate forming the fired body 4, the outermost layer green sheet (1B) on which the mounting electrode 7 is provided. The via hole (2B) in (1) forms a hole formed by machining. In other words, in the ceramic substrate 100 of the present invention, the plurality of green sheets constituting the green sheet laminate are “the outermost layer green sheet 1B having the machined via hole 2B” and “the laser processed via hole 2A”. And at least a combination with the provided internal green sheet 1A ”.
　図５に示される態様では、“ビアホールを有しないグリーンシート１Ｃ”が１枚、その上に“レーザ光を照射することによりビアホール２Ａを形成したグリーンシート１Ａ”が６枚、更にその上に、“最上層として機械加工によりビアホール２Ｂを有するグリーンシート１Ｂ”が１枚、順次、積層されることを通じて形成されている。図５に示されるようなセラミック基板１００を成す焼成体４は、各グリーンシートのビアホール２Ａ，２Ｂに導体ペーストを充填した後、実装電極７を形成する側に“機械加工によって形成されたビアホール２Ｂ”が位置付けられるように複数のグリーンシート（１Ａ、１Ｂ、１Ｃ）が積層・焼成されたものである。 In the embodiment shown in FIG. 5, there is one “green sheet 1C without via holes”, six “green sheets 1A with via holes 2A formed by irradiating laser light” thereon, and further, “Green sheet 1B having via hole 2B as a top layer by machining” is formed by sequentially laminating one sheet. In the fired body 4 forming the ceramic substrate 100 as shown in FIG. 5, the via holes 2A and 2B of each green sheet are filled with a conductive paste, and then the via hole 2B formed by machining is formed on the side where the mounting electrode 7 is formed. A plurality of green sheets (1A, 1B, 1C) are laminated and fired so that "" is positioned.
　図６には、レーザ光照射により形成されたビアホール２Ａを備えたグリーンシート１Ａの構成を示すと共に、図７には、機械加工により形成されたビアホール２Ｂを備えたグリーンシート１Ｂの構成を示す。 6 shows the configuration of a green sheet 1A provided with via holes 2A formed by laser light irradiation, and FIG. 7 shows the configuration of a green sheet 1B provided with via holes 2B formed by machining.
　図６に示す形態から分かるように、レーザ加工により形成されたビアホール２Ａは、レーザ光の拡り角度に起因して、ホール厚み方向にテーパ形状を有し得る。かかるテーパ形状を有するビアホール２Ａのテーパ角度α（ビアホール内壁とグリーンシート表面とが鋭角を成す角度）は、およそ４５°~８０°であり、例えば５０°~７０°である（図６参照）。このようなテーパ形状に起因して、レーザ加工により形成されたビアホール２Ａの断面（ビアホールの厚み方向に沿って平行な面で切り取ったホール断面）は、図６（ｂ）に示すように、略台形状を有し得る。ここで、ビアホール２Ａが“テーパ形状”／“略台形状”を有しているということは、かかるビアホール内に形成されているビア６Ａも、その厚み方向にテーパ形状を有していることを意味しており、それゆえ、かかるビアの断面（ビアの厚み方向に平行な面で切り取ったビア断面）もまた台形状を有していることを意味している。 As can be seen from the form shown in FIG. 6, the via hole 2 </ b> A formed by laser processing can have a taper shape in the hole thickness direction due to the spread angle of the laser beam. The taper angle α of the via hole 2A having such a tapered shape (the angle at which the via hole inner wall and the green sheet surface form an acute angle) is approximately 45 ° to 80 °, for example, 50 ° to 70 ° (see FIG. 6). Due to such a taper shape, the cross section of the via hole 2A formed by laser processing (hole cross section cut along a plane parallel to the thickness direction of the via hole) is substantially as shown in FIG. It can have a trapezoidal shape. Here, the via hole 2A has a “tapered shape” / “substantially trapezoidal shape” means that the via 6A formed in the via hole also has a tapered shape in the thickness direction. This means that the cross section of the via (via cross section cut by a plane parallel to the thickness direction of the via) also has a trapezoidal shape.
　あくまでも例示にすぎないが、「レーザ加工により形成されたビアホール２Ａ」、即ち、「ビア６Ａ」は、以下のような幅寸法（ｗＡ１，ｗＡ２）および高さ寸法（ｈＡ）を有している（図８（ａ）参照）：
●レーザ加工に起因したビアホール・ビアの幅寸法および高さ寸法
　・ｗＡ１：８０~１７０μｍ（例えば１００~１５０μｍ）
　・ｗＡ２：１１０~２００μｍ（例えば１３０~１８０μｍ）
　・ｈＡ：６０~３５０μｍ（例えば１５０~３００μｍ） For example, the “via hole 2A formed by laser processing”, that is, the “via 6A” has the following width dimensions (w A1 , w A2 ) and height dimensions (h A ). (See FIG. 8 (a)):
● Via hole and via width and height due to laser processing・ w A1 : 80 to 170 μm (for example, 100 to 150 μm)
・ W A2 : 110 to 200 μm (for example, 130 to 180 μm)
・ H A : 60 to 350 μm (for example, 150 to 300 μm)
　一方、図７に示す形態から分かるように、機械加工により形成されたビアホール２Ｂは、その機械加工に起因して、幅寸法がホール厚み方向に沿って略一定となり得る（ビアホール内壁とグリーンシート表面とが成す角度βは略直角≒９０°となっている）。つまり、機械加工により形成されたビアホール２Ｂの断面（ビアホールの厚み方向に沿って平行な面で切り取ったホール断面）は、図７（ｂ）に示すように、略矩形状または略正方形状を有している。ここで、ビアホール２Ｂが“幅方向寸法一定”／“略矩形状・略正方形状”を有しているということは、かかるビアホール内に形成されているビア６Ｂの幅寸法も、ビア厚み方向に沿って一定していることを意味しており、それゆえ、かかるビアの断面（ビアの厚み方向に平行な面で切り取ったビア断面）もまた矩形状または正方形状を有していることを意味している。 On the other hand, as can be seen from the form shown in FIG. 7, the via hole 2B formed by machining can have a substantially constant width along the hole thickness direction due to the machining (the inner wall of the via hole and the surface of the green sheet). The angle β formed by is substantially a right angle≈90 °). That is, the cross section of the via hole 2B formed by machining (hole cross section cut along a plane parallel to the thickness direction of the via hole) has a substantially rectangular shape or a substantially square shape as shown in FIG. is doing. Here, the via hole 2B having “constant width direction dimension” / “substantially rectangular shape / substantially square shape” means that the width dimension of the via 6B formed in the via hole is also in the via thickness direction. Means that the cross-section of the via (via cross-section cut by a plane parallel to the thickness direction of the via) also has a rectangular shape or a square shape. is doing.
　あくまでも例示にすぎないが、「機械加工により形成されたビアホール２Ｂ」、即ち、「ビア６Ｂ」は、以下のような幅寸法（ｗＢ）および高さ寸法（ｈＢ）の範囲を有している（図８（ｂ）参照）：
●機械加工に起因したビアホール・ビアの幅寸法および高さ寸法
　・ｗＢ：８０~１７０μｍ（例えば１００~１５０μｍ）
　・ｈＢ：６０~３５０μｍ（例えば１５０~３００μｍ） Although it is only an example, the “via hole 2B formed by machining”, that is, the “via 6B” has the following width dimension (w B ) and height dimension (h B ) ranges. (See FIG. 8B):
● Via hole and via width and height due to machining・ w B : 80 ~ 170μm (eg 100 ~ 150μm)
・ H B : 60 to 350 μm (for example, 150 to 300 μm)
　グリーンシート自体は、セラミック成分、ガラス成分および有機バインダ成分を含んで成るシート状部材であってよい。例えば、セラミック成分としては、アルミナ粉末（平均粒径：０．５~１０μｍ程度）であってよく、ガラス成分としては、ホウケイ酸塩ガラス粉末（平均粒径：１~２０μｍ程度）であってもよい。そして、有機バインダ成分としては、例えば、ポリビニルブチラール樹脂、アクリル樹脂、酢酸ビニル共重合体、ポリビニルアルコールおよび塩化ビニル樹脂から成る群から選択される少なくとも１種以上の成分であってよい。あくまでも例示にすぎないが、グリーンシート（１Ａ，１Ｂ，１Ｃ）は、アルミナ粉末４０~５０ｗｔ％、ガラス粉末を３０~４０ｗｔ％、および、有機バインダ成分１０~３０ｗｔ％であってよい（グリーンシートの全重量基準）。また、別の観点で捉えるとすると、グリーンシート（１Ａ，１Ｂ，１Ｃ）は、固体成分（アルミナ粉末５０~６０ｗｔ％およびガラス粉末を４０~５０ｗｔ％：固体成分の重量基準）と有機バインダ成分との重量比、即ち、固体成分重量：有機バインダ成分重量が８０~９０：１０~２０程度となっているものであってもよい。グリーンシート成分としては、必要に応じてその他の成分が含まれていてよく、例えば、フタル酸エステル、グリコールなどのケトン類の分散剤や有機溶剤などが含まれていてよい。グリーンシート（１Ａ，１Ｂ，１Ｃ）の厚さは６０~３５０μｍ程度であってよく、例えば１５０~３００μｍ程度であってもよい。 The green sheet itself may be a sheet-like member including a ceramic component, a glass component, and an organic binder component. For example, the ceramic component may be alumina powder (average particle size: about 0.5 to 10 μm), and the glass component may be borosilicate glass powder (average particle size: about 1 to 20 μm). Good. The organic binder component may be at least one component selected from the group consisting of polyvinyl butyral resin, acrylic resin, vinyl acetate copolymer, polyvinyl alcohol and vinyl chloride resin, for example. The green sheets (1A, 1B, and 1C) may be 40 to 50 wt% alumina powder, 30 to 40 wt% glass powder, and 10 to 30 wt% organic binder components, which are merely examples. Based on total weight). From another viewpoint, the green sheets (1A, 1B, 1C) are composed of a solid component (alumina powder 50-60 wt% and glass powder 40-50 wt%: based on the weight of the solid component) and an organic binder component. The weight ratio, that is, the solid component weight: organic binder component weight may be about 80 to 90:10 to 20. As the green sheet component, other components may be included as necessary, and for example, a dispersant of ketones such as phthalate ester and glycol, an organic solvent, and the like may be included. The thickness of the green sheets (1A, 1B, 1C) may be about 60 to 350 μm, for example, about 150 to 300 μm.
　ビア６Ａ，６Ｂは、ビアホール２Ａ，２Ｂに導電性材料が充填されることを通じて形成されるものである。具体的には、ビア６Ａ，６Ｂは、導電ペーストをビアホール２Ａ，２Ｂに印刷法などによって充填して熱処理などに付すことによって得られる。導電ペーストとしては、例えば、Ａｇ粉末と、接着強度を得るためのガラスフリットと、有機ビヒクル（例えばエチルセルロースとターピネオールとの有機混合物）とを含んで成るものであってよい。熱処理は、グリーンシート積層体の焼成に際して実施してよい。尚、グリーンシート積層体の焼成に先立って、ビアホール２Ａ，２Ｂに充填された導電ペーストを乾燥処理に付してもよい。 The vias 6A and 6B are formed by filling the via holes 2A and 2B with a conductive material. Specifically, the vias 6A and 6B are obtained by filling the via holes 2A and 2B with a conductive paste by a printing method or the like and subjecting to heat treatment or the like. The conductive paste may include, for example, Ag powder, glass frit for obtaining adhesive strength, and an organic vehicle (for example, an organic mixture of ethyl cellulose and terpineol). The heat treatment may be performed when the green sheet laminate is fired. Prior to firing the green sheet laminate, the conductive paste filled in the via holes 2A and 2B may be subjected to a drying process.
　本発明のセラミック基板１００を構成する焼成体４は、上述したように、複数のグリーンシート（１Ａ、１Ｂ、１Ｃ）を積層して焼成したものである。具体的には、図９に示すように、焼成前のグリーンシート積層体４’は、「レーザ光を照射することによりビアホール２Ａを形成したグリーンシート１Ａ」、「機械加工によりビアホール２Ｂを形成したグリーンシート１Ｂ」および必要に応じて設けられる「ビアホールを有しないセラミックシート１Ｃ」を所定の枚数重ねて熱圧着して形成される（各グリーンシートには、必要に応じてビア充填物や内部電極層・配線層などが印刷法などで設けられている）。そして、かかるグリーンシート積層体を焼成に付すことによって焼成体４が得られることになる。 As described above, the fired body 4 constituting the ceramic substrate 100 of the present invention is obtained by laminating and firing a plurality of green sheets (1A, 1B, 1C). Specifically, as shown in FIG. 9, the green sheet laminate 4 ′ before firing has “green sheet 1 </ b> A in which via hole 2 </ b> A is formed by irradiating laser light” and “via hole 2 </ b> B is formed by machining. A predetermined number of “green sheets 1B” and “ceramic sheets 1C without via holes” provided as necessary are formed by thermocompression bonding (each green sheet has via filling and internal electrodes as necessary. Layer, wiring layer, etc. are provided by the printing method). The fired body 4 is obtained by subjecting the green sheet laminate to firing.
　ちなみに、本発明のセラミック基板１００は、図１０に示すように、実装用電極７が予め設けられているものであってもよい。具体的には、図１０に示すように、積層体の最表層に位置するビア６Ｂ（ビアホール２Ｂ）と接するように実装用電極７が焼成体４上に設けられていてもよい。 Incidentally, as shown in FIG. 10, the ceramic substrate 100 of the present invention may be provided with mounting electrodes 7 in advance. Specifically, as illustrated in FIG. 10, the mounting electrode 7 may be provided on the fired body 4 so as to be in contact with the via 6 </ b> B (via hole 2 </ b> B) located in the outermost layer of the stacked body.
（本発明の電気回路モジュール）
　本発明の電気回路モジュールは、上記セラミック基板に実装された電子部品を有して成る。つまり、本発明の電気回路モジュール２００は、図１１に示すように、
　少なくとも１枚にはビアホールを有する複数枚のグリーンシートの積層体の焼成により形成された焼成体４、
　ビアホールに導電性材料が充填されることにより形成されたビア６、
　ビア６（特にビア６Ｂ）と接するように焼成体４上に設けられた実装用電極７、および
　実装用電極７上に半田９を介して実装されている電子部品１０
を有して成る。 (Electric circuit module of the present invention)
The electric circuit module of the present invention comprises an electronic component mounted on the ceramic substrate. In other words, the electric circuit module 200 of the present invention, as shown in FIG.
A fired body 4 formed by firing a laminate of a plurality of green sheets having via holes in at least one sheet;
A via 6 formed by filling a via hole with a conductive material;
Mounting electrode 7 provided on fired body 4 so as to be in contact with via 6 (particularly via 6B), and electronic component 10 mounted on mounting electrode 7 via solder 9
It has.
　図示するように、焼成体４上に設けられた実装用電極７は、最上層のビア６Ｂと電気的に接続するように設けられている。具体的には、図示するように、実装用電極７は、機械加工により形成されたビアホール２Ｂのビア６Ｂと接するように、かかるビア６Ｂの上に設けられている。あくまでも例示にすぎないが、電極７の厚さは２~１５０μｍ程度であってよい。 As shown, the mounting electrode 7 provided on the fired body 4 is provided so as to be electrically connected to the uppermost via 6B. Specifically, as illustrated, the mounting electrode 7 is provided on the via 6B so as to be in contact with the via 6B of the via hole 2B formed by machining. Although only illustrative, the thickness of the electrode 7 may be about 2 to 150 μm.
　このような電極７は、導電ペーストを焼成体４上にスクリーン印刷などで印刷して熱処理に付すことによって得られる。実装用電極７を形成するための導電ペーストは、一般的なセラミック基板の実装用電極や内部電極の形成に際して常套的に使用されているものであってよい。例えば、Ａｇペーストであってよい。熱処理は、後述するリフローはんだ付けに際して行ってよい。尚、リフローはんだ付けに先立って、電極７の形成のために印刷された導電ペーストを乾燥処理に付しておいてもよい。 Such an electrode 7 can be obtained by printing the conductive paste on the fired body 4 by screen printing or the like and subjecting it to a heat treatment. The conductive paste for forming the mounting electrode 7 may be one that is conventionally used in forming a mounting electrode or an internal electrode of a general ceramic substrate. For example, Ag paste may be used. The heat treatment may be performed during reflow soldering described later. Prior to the reflow soldering, the conductive paste printed for forming the electrode 7 may be subjected to a drying process.
　図１１に示す態様から分かるように、本発明の電気回路モジュール２００においては、実装用電極７が設けられる最表層に位置するビア６Ｂが“機械加工ホールに導電性材料を充填して形成されたビア”となっている。 As can be seen from the embodiment shown in FIG. 11, in the electric circuit module 200 of the present invention, the via 6 </ b> B located on the outermost layer on which the mounting electrode 7 is provided was formed by filling the machining hole with a conductive material. “Beer”.
　ここで、本発明の電気回路モジュール２００は、リフローはんだ付け工程を経て得られるものであり、具体的には、半田９を介在させたセラミック基板１００と電子部品１０とを一体的に熱処理に付すことによって得られるものである。 Here, the electric circuit module 200 of the present invention is obtained through a reflow soldering process. Specifically, the ceramic substrate 100 with the solder 9 interposed therebetween and the electronic component 10 are integrally subjected to heat treatment. Can be obtained.
　半田９の材質は、セラミック基板１００と電子部品１０との間を接合できるものであれば特に制限はなく、例えば、Ｓｎ−Ａｇ系、Ｓｎ−Ｂｉ系、Ｓｎ−Ｃｕ系、Ｓｎ−Ｉｎ系、Ｓｎ−Ｐｂ系もしくはＳｎ−Ｓｂ系などの２元合金材、あるいは、Ｓｎ−Ａｇ−Ｃｕ系、Ｓｎ−Ａｇ−Ｂｉ系、Ｓｎ−Ａｇ−Ｐｂ系、Ｓｎ−Ｂｉ−Ｉｎ系、Ｓｎ−Ｂｉ−Ｐｂ系、Ｓｎ−Ｚｎ−Ｂｉ系、Ｓｎ−Ｚｎ−Ｐｂ系などの３元合金材などであってよい。 The material of the solder 9 is not particularly limited as long as it can join the ceramic substrate 100 and the electronic component 10, for example, Sn—Ag system, Sn—Bi system, Sn—Cu system, Sn—In system, Binary alloy materials such as Sn-Pb or Sn-Sb, or Sn-Ag-Cu, Sn-Ag-Bi, Sn-Ag-Pb, Sn-Bi-In, Sn-Bi- It may be a ternary alloy material such as Pb, Sn—Zn—Bi, or Sn—Zn—Pb.
　セラミック基板１００の電極７上に実装される電子部品１０としては、特に制限されるものではないが、半導体、半導体ＩＣ、回路基板（例えばプリント配線基板など）、モジュール部品または受動部品などを挙げることができる。 The electronic component 10 mounted on the electrode 7 of the ceramic substrate 100 is not particularly limited, but includes a semiconductor, a semiconductor IC, a circuit board (for example, a printed wiring board), a module component or a passive component. Can do.
（本発明の作用および効果）
　次に、本発明の作用・効果について詳述する。本発明では、最表層グリーンシートの機械加工ビアホールに起因して、セラミック基板への電子部品実装時にて“ボイド発生”を防止することができ（特に、リフローはんだ付け工程で半田９にボイドが発生するのを防止することができ）、電子部品１０の接続不良を好適に回避することができる。 (Operation and effect of the present invention)
Next, functions and effects of the present invention will be described in detail. In the present invention, due to the machined via hole in the outermost layer green sheet, “void generation” can be prevented when electronic components are mounted on the ceramic substrate (particularly, a void is generated in the solder 9 in the reflow soldering process). Connection failure of the electronic component 10 can be suitably avoided.
　図１２（ａ）に示すように、レーザ光照射により形成されたビアホール２Ａを有するグリーンシート１Ａにおいては、ビアホール１Ａ内にて、レーザ光の照射による熱に起因した残留物が発生し得る。このようなレーザ加工ビアホール２Ａを備えたグリーンシート１Ａのみを積層してセラミック基板を構成した場合、残留物の量が多いと、その残留物の為に生じる“ビア内の空隙”にて、その後の製造工程で水分あるいは気泡が浸入し得る。それゆえ、セラミック基板および半田が加熱されると、気化した水分や気泡などがビア内を上昇してセラミック基板上の半田中においてボイドとして発生することになるので電子部品の接続不良が引き起こされ得る。 As shown in FIG. 12A, in the green sheet 1A having the via hole 2A formed by the laser beam irradiation, a residue due to the heat due to the laser beam irradiation may be generated in the via hole 1A. When the ceramic substrate is configured by laminating only the green sheet 1A having the laser processed via hole 2A, if the amount of the residue is large, the “void in the via” generated due to the residue causes In the manufacturing process, moisture or bubbles can enter. Therefore, when the ceramic substrate and the solder are heated, vaporized moisture, bubbles, etc. rise in the vias and are generated as voids in the solder on the ceramic substrate, which may cause poor connection of electronic components. .
　一方、図１２（ｂ）に示すように、機械加工により形成されたビアホール２Ｂを有するグリーンシート１Ｂでは、図１２（ａ）のような残留物は発生しない。即ち、実装用電極が設けられる最表層グリーンシートとして、機械加工ビアホール２Ｂを備えたグリーンシート１Ｂを用いることによって、実装用電極が配される層以外の層に「レーザ加工ビアホール２Ａを有するグリーンシート１Ａ」を用いたとしても、リフローはんだ付けに際して“機械加工ビアホールに形成されたビア”が「半田中にてボイドが発生する現象」を防止することになる。 On the other hand, as shown in FIG. 12B, the green sheet 1B having the via hole 2B formed by machining does not generate a residue as shown in FIG. That is, by using the green sheet 1B provided with the machined via hole 2B as the outermost layer green sheet on which the mounting electrode is provided, the “green sheet having the laser processed via hole 2A” is formed in a layer other than the layer where the mounting electrode is disposed. Even when “1A” is used, the “via formed in the machined via hole” at the time of reflow soldering prevents “a phenomenon in which voids are generated in the solder”.
　より具体的に説明すると、“機械加工ビアホールに形成されたビア６Ｂ”は、残留物に起因する空隙を含んでおらず、それゆえ、機械加工ビアホール内の実質的に全ての空間が導電性材料で充填されている。従って、“機械加工ビアホールに形成されたビア６Ｂ”よりも内部側に“レーザ加工ビアホールに形成されたビア６Ａ”が存在し、そこに水分あるいは気泡が含まれていたとしても、かかる水分・気泡の移動は最表層のビア６Ｂで阻止されることになる。つまり、リフローはんだ付けに際しては、“機械加工ビアホールに形成されたビア６Ｂ”が、“レーザ加工ビアホールに形成されたビア６Ａ”に含まれていた水分や気泡の透過・移動を阻止することになり、その結果、それらが半田９まで移動することが防止される。 More specifically, the “via 6B formed in the machined via hole” does not include voids due to residue, and therefore, substantially all the space in the machined via hole is made of a conductive material. Filled with. Therefore, even if the “via 6A formed in the laser processed via hole” exists on the inner side of the “via 6B formed in the machined via hole” and the moisture or the bubble is included therein, the moisture / bubble is generated. Is prevented by the outermost via 6B. In other words, during reflow soldering, “via 6B formed in a machined via hole” prevents transmission and movement of moisture and bubbles contained in “via 6A formed in a laser processed via hole”. As a result, they are prevented from moving to the solder 9.
（本発明のセラミック基板および電気回路モジュールの製造方法）
　次に、本発明のセラミック基板および電気回路モジュールの製造方法について説明する。まず、本発明のセラミック基板の製造方法について説明し、その後、当該製造方法で得られたセラミック基板を用いる電気回路モジュールの製造方法を説明する。 (Manufacturing method of ceramic substrate and electric circuit module of the present invention)
Next, a method for manufacturing a ceramic substrate and an electric circuit module according to the present invention will be described. First, a method for manufacturing a ceramic substrate of the present invention will be described, and then a method for manufacturing an electric circuit module using the ceramic substrate obtained by the manufacturing method will be described.
　まず、本発明のセラミック基板の製造方法の実施に際しては、工程（ｉ）を実施する。つまり、複数のグリーンシートの少なくとも１枚にビアホールを形成する。 First, in carrying out the method for manufacturing a ceramic substrate of the present invention, step (i) is performed. That is, a via hole is formed in at least one of the plurality of green sheets.
　具体的には、図１３（ａ）に示すように、積層体の最表層として設けられるグリーンシート１Ｂのビアホール２Ｂを機械加工によって形成する一方（図Ｐ（ａ）の“ａ１”）、それ以外の層として設けられるグリーンシート１Ａのビアホール２Ａをレーザ加工によって形成する（図１３（ａ）の“ａ２”）。 Specifically, as shown in FIG. 13 (a), the via hole 2B of the green sheet 1B provided as the outermost layer of the laminate is formed by machining (“a1” in FIG. P (a)), the other A via hole 2A of the green sheet 1A provided as a layer is formed by laser processing (“a2” in FIG. 13A).
　ビアホール２Ｂの機械加工は、パンチプレスを実施することが好ましい。つまり、パンチプレス加工を実施することによって、積層体の最表層に相当するグリーンシート１Ｂのビアホール２Ｂを形成することが好ましい。パンチプレスの種類としては、ピン部材によって穴を開けることができるもの（即ち、抜き加工できるもの）であれば、いずれの種類であってもよく、例えば、数値制御によって行うＮＣパンチプレス（Ｎｕｍｅｒｉｃａｌ　Ｃｏｎｔｒｏｌパンチプレス）であってよいし、あるいは、金型状のプレスとして複数のビアホールを一括して抜き加工するパンチプレスであってもよい。このようなパンチプレスでは、ビアホール２Ｂの形状が略円柱形状になる、即ち、ホール厚みの方向に沿ってビアホール２Ｂの幅寸法が略一定となる。 It is preferable to perform a punch press for machining the via hole 2B. That is, it is preferable to form the via hole 2B of the green sheet 1B corresponding to the outermost layer of the laminated body by performing punch press processing. The punch press may be of any type as long as it can punch a hole with a pin member (ie, can be punched). For example, NC punch press (Numerical Control) is performed by numerical control. Punch press), or a punch press that punches a plurality of via holes as a die-shaped press. In such a punch press, the via hole 2B has a substantially cylindrical shape, that is, the width dimension of the via hole 2B is substantially constant along the direction of the hole thickness.
　一方、ビアホール１Ａのレーザ加工では、炭酸ガス（ＣＯ２）レーザ、ＹＡＧレーザ、エキシマレーザなどを用いてよい。レーザ加工条件（レーザ出力、動作周波数など）は、グリーンシートのビアホール形成として常套的に用いられているものであれば特に制限はない。このようなレーザ加工においては、レーザ光の拡り角度に起因して、ビアホール２Ａの形状が円錐台形状となる、即ち、ビアホール２Ａがホール厚みの方向にテーパ形状を有し得る。 On the other hand, in the laser processing of the via hole 1A, a carbon dioxide (CO 2 ) laser, a YAG laser, an excimer laser, or the like may be used. The laser processing conditions (laser output, operating frequency, etc.) are not particularly limited as long as they are conventionally used for forming via holes in green sheets. In such laser processing, the shape of the via hole 2A becomes a truncated cone due to the spread angle of the laser beam, that is, the via hole 2A can have a taper shape in the direction of the hole thickness.
　工程（ｉ）に引き続いて、工程（ｉｉ）を実施する。つまり、ビアホール（２Ａ，２Ｂ）に導電性材料を充填する。具体的には、図１３（ｂ）に示すように、グリーンシート１Ａ，１Ｂに形成したビアホール（２Ａ，２Ｂ）に対して導電ペーストを供給し、それらホール（２Ａ，２Ｂ）の内部を導電ペーストで埋める。このような導電性材料の供給に際しては、スクリーン印刷などの各種印刷法を用いることができる。導電ペーストをビアホール（２Ａ，２Ｂ）内に充填した後で乾燥に付すことが好ましい。また、ビアホール（２Ａ，２Ｂ）内に導電ペーストを充填した後では、必要な配線層や内部電極を同様に各種印刷法によって形成してよい（尚、かかる配線層や内部電極の形成前後では乾燥処理を行うことが好ましく、例えば４０~８０℃の温度条件で２０~５０分の乾燥処理を行ってよい）。 Next to step (i), step (ii) is performed. That is, the via hole (2A, 2B) is filled with a conductive material. Specifically, as shown in FIG. 13B, conductive paste is supplied to the via holes (2A, 2B) formed in the green sheets 1A, 1B, and the inside of the holes (2A, 2B) is electrically conductive paste. Fill with. When supplying such a conductive material, various printing methods such as screen printing can be used. It is preferable to dry after filling the conductive paste into the via holes (2A, 2B). In addition, after filling the via holes (2A, 2B) with the conductive paste, necessary wiring layers and internal electrodes may be formed by various printing methods in the same manner. It is preferable to perform a treatment, for example, a drying treatment of 20 to 50 minutes may be performed under a temperature condition of 40 to 80 ° C.).
　工程（ｉｉ）に引き続いて工程（ｉｉｉ）を実施する。つまり、複数のグリーンシートを積層して積層体を形成し、その積層体を焼成に付すことによって焼成体を得る。具体的には、図１３（ｃ）に示すように、「レーザ光を照射することによりビアホールを形成したグリーンシート１Ａ」、「機械加工によりビアホールを形成したグリーンシート１Ｂ」および必要に応じて用いられる「ビアホールを備えていないセラミックシート１Ｃ」を所定の枚数重ねて熱圧着してグリーンシート積層体４’を得る（例えば、温度７０℃~９０℃、圧力１００Ｋｇ／ｃｍ２~３００Ｋｇ／ｃｍ２の条件で熱圧着してよい）。特に本発明では、最表層に位置するグリーンシート（即ち、図示するように最も上側に位置するグリーンシート）として「機械加工によりビアホール２Ｂを形成したグリーンシート１Ｂ」を用いる。積層されるグリーンシート枚数（１Ａ，１Ｂ，１Ｃ）は特に制限はなく、例えば総計で３~５０枚程度であってよく、好ましくは３~１５枚程度である。 Subsequent to step (ii), step (iii) is performed. That is, a laminated body is formed by laminating a plurality of green sheets, and the laminated body is subjected to firing to obtain a fired body. Specifically, as shown in FIG. 13C, “green sheet 1A in which via holes are formed by laser irradiation”, “green sheet 1B in which via holes are formed by machining”, and as necessary. A predetermined number of “ceramic sheets 1C without via holes” are stacked and thermocompression bonded to obtain a green sheet laminate 4 ′ (for example, at a temperature of 70 ° C. to 90 ° C. and a pressure of 100 kg / cm 2 to 300 kg / cm 2 . It may be thermocompression bonded under certain conditions). In particular, in the present invention, “green sheet 1B in which via hole 2B is formed by machining” is used as the green sheet positioned on the outermost layer (that is, the green sheet positioned on the uppermost side as shown). The number of stacked green sheets (1A, 1B, 1C) is not particularly limited, and may be, for example, about 3 to 50 in total, preferably about 3 to 15 sheets.
　グリーンシート積層体４’は、焼成に先立って、脱バインダ工程などの乾燥処理に付されることが好ましい。例えば、脱バインダ工程として、５００℃~７００℃の温度条件で２０~５０時間の加熱処理に付してよい。そして、焼成に際しては、例えば８００℃~１０００℃（好ましくは８５０℃~９５０℃）の温度条件で０．１時間~３時間ほどグリーンシート積層体４’を加熱処理することが好ましい。このような加熱処理は、グリーンシート積層体４’をメッシュベルト炉などの焼成炉に供することによって行ってよい。ちなみに、以上のような焼成法は、特開平５−１０２６６６号公報に開示されているので必要に応じて参考にされたい。 The green sheet laminate 4 ′ is preferably subjected to a drying process such as a binder removal step prior to firing. For example, as the binder removal step, heat treatment may be performed for 20 to 50 hours under a temperature condition of 500 ° C. to 700 ° C. In firing, the green sheet laminate 4 ′ is preferably heat-treated at a temperature of 800 ° C. to 1000 ° C. (preferably 850 ° C. to 950 ° C.) for about 0.1 hour to 3 hours. Such heat treatment may be performed by subjecting the green sheet laminate 4 ′ to a firing furnace such as a mesh belt furnace. Incidentally, the firing method as described above is disclosed in Japanese Patent Laid-Open No. 5-102666, and should be referred to as necessary.
　以上のように焼成を経ることによって、図１３（ｄ）に示すように、焼成体４及びその内部にビア６（６Ａ，６Ｂ）が設けられたセラミック基板１００を得ることができる。 By performing the firing as described above, as shown in FIG. 13D, the ceramic substrate 100 provided with the fired body 4 and vias 6 (6A, 6B) therein can be obtained.
　引き続いて、本発明の電気回路モジュールの製造方法を説明する。かかる製造方法の実施に際しては、まず、工程（Ｉ）を実施する。つまり、得られたセラミック基板のビアと接するように焼成体上に実装用電極を形成する。 Subsequently, a method for manufacturing the electric circuit module of the present invention will be described. In carrying out this manufacturing method, first, step (I) is carried out. That is, the mounting electrode is formed on the fired body so as to be in contact with the via of the obtained ceramic substrate.
　具体的には、図１４（ａ）および（ｂ）に示すように、電極原料となる導電ペーストを焼成体４上にスクリーン印刷などで供することによって電極７を形成する。特に実装用電極７を形成するための導電ペーストとしては、例えばＡｇペーストであってよい。 Specifically, as shown in FIGS. 14A and 14B, the electrode 7 is formed by providing a conductive paste as an electrode material on the fired body 4 by screen printing or the like. In particular, the conductive paste for forming the mounting electrode 7 may be an Ag paste, for example.
　工程（Ｉ）に引き続いて、工程（ＩＩ）を実施する。つまり、実装用電極上に半田を設けて、その半田の上に電子部品を配置する。例えば、図１４（ｃ）および（ｄ）に示すように、実装用電極７上に半田ボール９を設けて、その半田ボール９の上に電子部品１０として半導体ＩＣを設けてよい。 Next to step (I), step (II) is performed. That is, solder is provided on the mounting electrode, and an electronic component is disposed on the solder. For example, as shown in FIGS. 14C and 14D, a solder ball 9 may be provided on the mounting electrode 7 and a semiconductor IC may be provided as the electronic component 10 on the solder ball 9.
　工程（ＩＩ）に引き続いて、工程（ＩＩＩ）を実施する。つまり、リフローはんだ付け工程を実施する。具体的には、図１４（ｅ）に示すように、セラミック基板１００、電気部品１０およびそれらの間に介在する半田ボール９および電極７を一体的に加熱処理に付す。これによって、セラミック基板１００と電気部品１０とが半田材を介して相互に電気的に接続され、電気回路モジュール２００が得られることになる。 Next to step (II), step (III) is performed. That is, a reflow soldering process is performed. Specifically, as shown in FIG. 14E, the ceramic substrate 100, the electrical component 10, and the solder balls 9 and the electrodes 7 interposed therebetween are integrally subjected to a heat treatment. As a result, the ceramic substrate 100 and the electrical component 10 are electrically connected to each other via the solder material, and the electrical circuit module 200 is obtained.
　ここで、上述したように、リフローはんだ付け工程に際しては、“機械加工ビアホールに形成されたビア６Ｂ”が、“レーザ加工ビアホールに形成されたビア６Ａ”に起因して生じる水分や気泡の透過・移動を阻止するので、かかる水分や気泡が半田ボール９へと移動せず、結果的に、半田中のボイド発生が防止される。 Here, as described above, in the reflow soldering process, the “via 6B formed in the machined via hole” is changed from the transmission of moisture and bubbles caused by the “via 6A formed in the laser processed via hole”. Since the movement is prevented, such moisture and bubbles do not move to the solder ball 9, and as a result, generation of voids in the solder is prevented.
　なお、本発明の製造方法では、セラミック基板内部にビアホールの形成が必要な場合、電極を形成する層以外の層には「レーザ光照射により形成されたビアホールを有するグリーンシート」を用いることができる。かかる場合、レーザ照射によるビアホール形成時間（工程タクトタイム）が、機械加工（例えばＮＣパンチプレス）によるビアホール形成時間（工程タクトタイム）の約６分の１であるので、生産性を大きく高めることができる。つまり、本発明では、セラミック基板製造におけるタクトタイムに実質的な悪影響を与えることなく、セラミック基板の製造自体、ひいては、それを用いた電気回路モジュール製造における工程歩留りの向上を図ることができる（その結果として、セラミック基板およびそれを用いた電気回路モジュールを安価で市場に提供することができる）。 In the manufacturing method of the present invention, when it is necessary to form a via hole in the ceramic substrate, a “green sheet having a via hole formed by laser light irradiation” can be used for a layer other than the layer for forming the electrode. . In this case, the via hole formation time (process tact time) by laser irradiation is about one-sixth of the via hole formation time (process tact time) by machining (for example, NC punch press). it can. That is, according to the present invention, the manufacturing yield of the ceramic substrate itself and, consequently, the process yield in the electrical circuit module manufacturing using the ceramic substrate can be improved without substantially adversely affecting the tact time in the ceramic substrate manufacturing. As a result, the ceramic substrate and the electric circuit module using the ceramic substrate can be provided to the market at a low cost).
　以上、本発明の実施形態について説明してきたが、あくまでも典型例を例示したに過ぎない。従って、本発明はこれに限定されず、種々の態様が考えられる。例えば以下の態様が考えられる。
●　本発明のセラミック基板では、実装用電極が設けられる最表層に位置するビアが機械加工ホールに導電性材料を充填して形成されたビアとなっていればよい。従って、図１５に示すように、実装用電極７が設けられる最上層グリーンシートにおけるビアホールが機械加工で形成されているのみならず、実装用電極７が設けられる最下層グリーンシートにおけるビアホールも機械加工で形成されていてよい。つまり、最上層および最下層の双方に位置するビアが“機械加工ホールに導電性材料を充填して形成されたビア”となっていてよい。かかる態様であっても、上述した本発明の効果が同様に奏されることになる。かかる態様は、基板両面に電子部品を実装できる点で有用である。尚、参考までに、本発明のセラミック基板の典型的なビア／ビアホールの全体形状を図１６に示しておく。図１６（ａ）が片面実装用基板におけるビア・ビアホールの全体形状を示しており、図１６（ｂ）が両面実装用基板におけるビア・ビアホールの全体形状を示している。
●　本発明では、グリーンシート積層体のうち、少なくとも最表層のグリーンシートにおけるビアホールが機械加工で形成されていればよい。つまり、場合によっては、かかる最表層グリーンシートの下層に相当する少なくとも１枚のグリーンシートのビアホールもまた機械加工で形成されていてもよい。かかる場合であっても、上述した本発明の効果が同様に奏される。
●　本発明の本質的特徴に鑑みると、電極を介して実装する態様のみならず、そのような電極を介さずとも半田で電子部品をセラミック基板に直接的に実装する態様であっても、上述した本発明の効果が同様に奏される。つまり、実装用電極を用いずに、本発明のセラミック基板と電子部品とそれらの間の半田とがはんだリフロー付けに付される場合であっても、“機械加工ビアホールに形成されたビア６Ｂ”が、“レーザ加工ビアホールに形成されたビア６Ａ”に起因して生じる水分や気泡の透過・移動を阻止するので、結果として半田中でのボイド発生が防止される。
　●　本発明の本質的特徴に鑑みると、本発明は“はんだリフロー工法”に際して効果を発揮するだけでなく、熱処理に起因した他の実装工法であっても同様に効果が発揮され得るものである。例えば、ＧＧＩ（Ｇｏｌｄ−ｔｏ−Ｇｏｌｄ）工法であっても、同様に効果が奏され得る。具体的には、セラミック基板に形成した金パッドと電子部品に形成した金パッドとを熱圧着により接合し、溶融したアンダーフィル材を接合部の周囲に供給する場合であっても、加熱環境に曝されることには変わりはないので、その際の“パッド中のボイド発生”を本発明によって防止することができる。 As mentioned above, although embodiment of this invention has been described, it has only illustrated the typical example to the last. Therefore, the present invention is not limited to this, and various modes are conceivable. For example, the following modes can be considered.
In the ceramic substrate of the present invention, the via located in the outermost layer on which the mounting electrode is provided may be a via formed by filling a machining hole with a conductive material. Accordingly, as shown in FIG. 15, not only the via hole in the uppermost green sheet provided with the mounting electrode 7 is formed by machining, but also the via hole in the lowermost green sheet provided with the mounting electrode 7 is machined. May be formed. That is, the vias located in both the uppermost layer and the lowermost layer may be “vias formed by filling a machining hole with a conductive material”. Even in such an embodiment, the above-described effects of the present invention are similarly obtained. This aspect is useful in that electronic components can be mounted on both sides of the substrate. For reference, the overall shape of a typical via / via hole of the ceramic substrate of the present invention is shown in FIG. FIG. 16A shows the overall shape of vias and via holes in a single-sided mounting board, and FIG. 16B shows the overall shape of vias and via holes in a double-sided mounting board.
● In the present invention, at least the outermost green sheet of the green sheet laminate need only be formed by machining. That is, in some cases, at least one green sheet via hole corresponding to the lower layer of the outermost surface green sheet may also be formed by machining. Even in such a case, the above-described effects of the present invention are similarly obtained.
● In view of the essential features of the present invention, not only the mode of mounting through electrodes, but also the mode of mounting electronic components directly on a ceramic substrate with solder without using such electrodes, The effects of the present invention are also exhibited. That is, even when the ceramic substrate of the present invention, the electronic component, and the solder between them are subjected to solder reflow without using mounting electrodes, “via 6B formed in a machined via hole” However, since the penetration and movement of moisture and bubbles caused by the “via 6A formed in the laser processed via hole” are blocked, the generation of voids in the solder is prevented as a result.
● In view of the essential features of the present invention, the present invention is not only effective in the “solder reflow method”, but can also be effective in other mounting methods resulting from heat treatment. . For example, even if it is GGI (Gold-to-Gold) construction method, an effect can be produced similarly. Specifically, even when a gold pad formed on a ceramic substrate and a gold pad formed on an electronic component are bonded by thermocompression bonding and a molten underfill material is supplied around the bonded portion, the heating environment is maintained. Since there is no change in exposure, the “void formation in the pad” at that time can be prevented by the present invention.
　最後に、本発明は下記の態様を有するものであることを確認的に付言しておく。
第１態様：少なくとも１枚にはビアホールを有する複数枚のグリーンシートの積層体の焼成（または焼結）により形成された焼成体（または焼結体）、および
　ビアホールに導電性材料が充填されることにより形成されたビア
を有して成るセラミック基板であって、
　グリーンシート積層体につき、少なくとも「実装用電極が設けられる最表層のグリーンシートにおけるビアホール」が機械加工により形成されたビアホールとなっているセラミック基板。
第２態様：上記第１態様において、機械加工により形成されたビアホールのホール幅寸法が、ホール厚み方向に沿って一定していることを特徴とするセラミック基板。
第３態様：上記の第１態様または第２態様において、「最表層のグリーンシート以外のグリーンシートにおけるビアホール」がレーザ加工により形成されたビアホールであることを特徴とするセラミック基板。
第４態様：上記第３態様において、レーザ加工により形成されたビアホールのホール幅寸法が、ホール厚み方向に沿って一定しておらず、漸次減少または漸次増加していることを特徴とするセラミック基板。
第５態様：上記の第１態様~第４態様のいずれかにおいて、ビアと接するように焼成体上に設けられた電極を更に有して成ることを特徴とするセラミック基板。
第６態様：上記の第１態様~第４態様のいずれかのセラミック基板を有して成る電気回路モジュール（電子回路モジュール）であって、
　ビアと接するように焼成体上に設けられた実装用電極、および
　実装用電極上に実装されている電子部品
を有して成る電気回路モジュール（電子回路モジュール）。
第７態様：セラミック基板を製造するための方法であって、
　（ｉ）複数のグリーンシートの少なくとも１枚にビアホールを形成する工程、
　（ｉｉ）ビアホールに導電性材料を充填する工程、および
　（ｉｉｉ）複数のグリーンシートを積層することによって積層体を形成し、当該積層体を焼成に付して焼成体を得る工程
を含んで成り、
　工程（ｉ）では、「グリーンシート積層体の最外層として用いられて実装用電極が設けられる最表層グリーンシート」におけるビアホールを機械加工によって形成する、セラミック基板の製造方法。
第８態様：上記第７態様において、機械加工としてパンチプレスを実施することを特徴とするセラミック基板の製造方法。
第９態様：上記第７態様または第８態様において、工程（ｉ）では「最表層グリーンシート以外のグリーンシート」におけるビアホールをレーザ加工によって形成することを特徴とするセラミック基板の製造方法。
第１０態様：上記の第１態様~第４態様のいずれかのセラミック基板を用いた電気回路モジュール（電子回路モジュール）の製造方法であって、
　（Ｉ）セラミック基板のビアと接するように焼成体上に実装用電極を形成する工程、
　（ＩＩ）実装用電極上に半田を設けて、当該半田上に電子部品を配する工程、および
　（ＩＩＩ）「セラミック基板、電気部品およびそれらの間に介在する半田および実装用電極」をリフローはんだ付けに付す工程
を含んで成る電気回路モジュール（電子回路モジュール）の製造方法。 Finally, it should be confirmed that the present invention has the following aspects.
First embodiment : At least one sheet is a fired body (or sintered body) formed by firing (or sintering) a laminate of a plurality of green sheets having via holes, and the via hole is filled with a conductive material. A ceramic substrate having vias formed by:
A ceramic substrate in which at least “a via hole in the outermost green sheet on which a mounting electrode is provided” is a via hole formed by machining for the green sheet laminate.
Second aspect : The ceramic substrate according to the first aspect, wherein the hole width dimension of the via hole formed by machining is constant along the hole thickness direction.
Third aspect : The ceramic substrate according to the first or second aspect, wherein the “via hole in the green sheet other than the outermost green sheet” is a via hole formed by laser processing.
Fourth aspect : The ceramic substrate according to the third aspect, wherein the hole width dimension of the via hole formed by laser processing is not constant along the hole thickness direction but gradually decreases or gradually increases. .
Fifth aspect : The ceramic substrate according to any one of the first to fourth aspects, further comprising an electrode provided on the fired body so as to be in contact with the via.
Sixth aspect : An electric circuit module (electronic circuit module) comprising the ceramic substrate according to any one of the first to fourth aspects,
An electrical circuit module (electronic circuit module) comprising a mounting electrode provided on a fired body so as to be in contact with a via, and an electronic component mounted on the mounting electrode.
Seventh aspect : A method for producing a ceramic substrate, comprising:
(I) forming a via hole in at least one of the plurality of green sheets;
(Ii) filling a via hole with a conductive material, and (iii) forming a laminate by laminating a plurality of green sheets, and subjecting the laminate to firing to obtain a fired body. ,
In the step (i), a method of manufacturing a ceramic substrate, wherein via holes are formed by machining in the “outermost layer green sheet used as an outermost layer of a green sheet laminate and provided with a mounting electrode”.
Eighth aspect : A method for producing a ceramic substrate according to the seventh aspect, wherein a punch press is performed as the machining.
Ninth aspect : In the seventh aspect or the eighth aspect, in the step (i), the via hole in the “green sheet other than the outermost layer green sheet” is formed by laser processing.
Tenth aspect : A method of manufacturing an electric circuit module (electronic circuit module) using the ceramic substrate according to any one of the first to fourth aspects,
(I) forming a mounting electrode on the fired body so as to be in contact with the via of the ceramic substrate;
(II) a step of providing solder on the mounting electrode and arranging electronic components on the solder; and (III) reflow soldering the “ceramic substrate, electrical component and solder interposed between them and mounting electrode” A method of manufacturing an electric circuit module (electronic circuit module) comprising a step of attaching.
　本発明の効果を確認するために、「電極を形成する層のグリーンシートとして、機械加工によって形成したビアホールを備えた最表層グリーンシートを用いた場合（図５の態様）」（実施例１）と、「電極を形成する層のグリーンシートとして、レーザ照射によって形成したビアホールを備えた最表層グリーンシートを用いた場合」（比較例１）とについて比較試験を行った。 In order to confirm the effect of the present invention, “when the outermost layer green sheet provided with via holes formed by machining is used as the green sheet of the layer for forming the electrode (aspect of FIG. 5)” (Example 1) A comparative test was conducted with respect to “when the outermost layer green sheet provided with a via hole formed by laser irradiation was used as the green sheet of the layer forming the electrode” (Comparative Example 1).
グリーンシート成分
　・アルミナ粉末：　　４６．４ｗｔ％
　・ガラス粉末：　　　３８．０ｗｔ％
　・有機バインダ成分：１５．６ｗｔ％
レーザ加工ビアホール寸法（図８（ａ）参照）
　・ｗＡ１：約１２５μｍ
　・ｗＡ２：約１５５μｍ
　・ｈＡ：１７５μｍ
機械加工ビアホール寸法（図８（ｂ）参照）
　・ｗＢ：約１２５μｍ
　・ｈＢ：１７５μｍ
シート積層数
（実施例１）
　・最上層グリーンシート（機械加工ビアシート）：１枚
　・内部グリーンシート（レーザ加工ビアシート）：９枚
　・最下層グリーンシート（ビア加工無しシート）：１枚
（比較例１）
　・最上層グリーンシート（レーザ加工ビアシート）：１枚
　・内部グリーンシート（レーザ加工ビアシート）：９枚
　・最下層グリーンシート（ビア加工無しシート）：１枚 Green sheet component / alumina powder: 46.4wt%
・ Glass powder: 38.0wt%
・ Organic binder component: 15.6wt%
Laser processed via hole dimensions (see Fig. 8 (a))
・ W A1 : About 125μm
・ W A2 : About 155 μm
・ H A : 175 μm
Machined via hole dimensions (see Fig. 8 (b))
・ W B : About 125μm
· H B: 175μm
Number of stacked sheets (Example 1)
-Uppermost green sheet (machined via sheet): 1 sheet-Internal green sheet (laser processed via sheet): 9 sheets-Lowermost green sheet (sheet without via process): 1 sheet (Comparative Example 1)
-Uppermost green sheet (laser processed via sheet): 1 sheet-Internal green sheet (laser processed via sheet): 9 sheets-Lowermost layer green sheet (sheet without via process): 1 sheet
　結果を図１７に示す。図１７に示されるように、「レーザ照射によって形成したビアホールを備えた最表層グリーンシートを用いた場合（比較例１）」のボイド発生率は１０％（２０個／２００個）であったものの（図１７（ａ）参照）、「機械加工によって形成したビアホールを備えた最表層グリーンシートを用いた場合（実施例１）」のボイド発生率はゼロ（発生なし＝０個／２００個）であった（図１７（ｂ）参照）。 Results are shown in FIG. As shown in FIG. 17, the void generation rate in the case of using the outermost layer green sheet having via holes formed by laser irradiation (Comparative Example 1) was 10% (20/200). (Refer to FIG. 17 (a)), the void generation rate in the case of using the outermost layer green sheet with via holes formed by machining (Example 1) is zero (no generation = 0/200). (See FIG. 17B).
　上記実施例１のビア個数は２００個であったが、同様の試験をビア個数４８０万個の条件でも実施した。その結果、「機械加工によって形成したビアホールを備えた最表層グリーンシートを用いた場合（実施例２）」のボイド発生率はゼロ（発生なし＝０個／４８０万個）であった。このことから、本発明は、セラミック基板に電子部品を実装して電気回路モジュールを製造する際の歩留まり向上に対して極めて優れた効果を有することが理解できるであろう。 The number of vias in Example 1 was 200, but the same test was performed under the condition where the number of vias was 4.8 million. As a result, the void generation rate in the case of using the outermost surface green sheet provided with the via hole formed by machining (Example 2) was zero (no generation = 0 / 4.8 million). From this, it will be understood that the present invention has an extremely excellent effect for improving the yield when an electronic component is manufactured by mounting electronic components on a ceramic substrate.
　本発明に係るセラミック基板は、モバイル機器のＲＦモジュールや放熱性を利用したパワーＬＥＤ用の基板や液晶のバックライト向けＬＥＤ用の基板として好適に用いられると共に、電子部品が高密度実装された電子機器の基板などとしても好適に用いられる。 The ceramic substrate according to the present invention is suitably used as an RF module of a mobile device, a power LED substrate using heat dissipation, or an LED substrate for a liquid crystal backlight, and an electronic component mounted with high density. It is also suitably used as a substrate for equipment.
　特に本発明は、積層体の最表層グリーンシートにおける機械加工ビアホールに起因して、はんだリフローでセラミック基板上に電子部品を実装して電気回路モジュールを得る場合であっても、半田内部でのボイド発生を好適的に防止できるので有用である。
In particular, the present invention provides a void inside the solder even when the electronic component is obtained by mounting electronic components on a ceramic substrate by solder reflow due to the machined via hole in the outermost green sheet of the laminate. Since generation | occurrence | production can be prevented suitably, it is useful.
関連出願の相互参照Cross-reference of related applications
　本出願は、日本国特許出願第２０１０−０３３１２８号（出願日：２０１０年２月１８日、発明の名称「セラミック基板、および電気回路モジュール」）に基づくパリ条約上の優先権を主張する。当該出願に開示された内容は全て、この引用により、本明細書に含まれるものとする。 This application claims priority under the Paris Convention based on Japanese Patent Application No. 2010-033128 (filing date: February 18, 2010, title of the invention “ceramic substrate and electrical circuit module”). All the contents disclosed in the application are incorporated herein by this reference.

Claims (9)

  1. 　セラミック基板であって、
    　少なくとも１枚にはビアホールを有する複数枚のグリーンシートの積層体の焼成により形成された焼成体、および
    　前記ビアホールに導電性材料が充填されることにより形成されたビア
    を有して成り、
    　前記積層体につき、実装用電極が設けられる最表層の前記グリーンシートにおける前記ビアホールが、機械加工により形成されたビアホールである、セラミック基板。     A ceramic substrate,
    At least one sheet comprises a fired body formed by firing a laminate of a plurality of green sheets having via holes, and a via formed by filling the via hole with a conductive material,
    A ceramic substrate in which the via hole in the outermost green sheet on which the mounting electrode is provided is a via hole formed by machining in the laminate.
  2. 　前記最表層のグリーンシート以外の前記グリーンシートにおける前記ビアホールが、レーザ加工により形成されたビアホールであることを特徴とする、請求項１に記載のセラミック基板。 2. The ceramic substrate according to claim 1, wherein the via hole in the green sheet other than the outermost green sheet is a via hole formed by laser processing.
  3. 　前記機械加工により形成されたビアホールは、その厚み方向に沿って幅寸法が一定していることを特徴とする、請求項１に記載のセラミック基板。 2. The ceramic substrate according to claim 1, wherein a width dimension of the via hole formed by the machining is constant along a thickness direction thereof.
  4. 　前記レーザ加工により形成されたビアホールが、その厚み方向にテーパ形状を有していることを特徴とする、請求項２に記載のセラミック基板。 3. The ceramic substrate according to claim 2, wherein the via hole formed by the laser processing has a taper shape in a thickness direction thereof.
  5. 　請求項１に記載のセラミック基板を有して成る電気回路モジュールであって、
    　前記ビアと接するように前記焼成体上に設けられた実装用電極、および
    　前記実装用電極上に実装されている電子部品
    を有して成る、電気回路モジュール。     An electric circuit module comprising the ceramic substrate according to claim 1,
    An electric circuit module comprising: a mounting electrode provided on the fired body so as to be in contact with the via; and an electronic component mounted on the mounting electrode.
  6. 　セラミック基板を製造するための方法であって、
    　（ｉ）複数のグリーンシートの少なくとも１枚にビアホールを形成する工程、
    　（ｉｉ）前記ビアホールに導電性材料を充填する工程、および
    　（ｉｉｉ）前記複数のグリーンシートを積層することによって積層体を形成し、該積層体を焼成に付して焼成体を得る工程
    を含んで成り、
    　前記工程（ｉ）では、前記積層体の最表層として用いられて実装用電極が設けられる前記グリーンシートにおける前記ビアホールを機械加工によって形成する、セラミック基板の製造方法。     A method for manufacturing a ceramic substrate, comprising:
    (I) forming a via hole in at least one of the plurality of green sheets;
    (Ii) filling the via hole with a conductive material; and (iii) forming a laminate by laminating the plurality of green sheets, and subjecting the laminate to firing to obtain a fired body. Consisting of
    In the step (i), the via hole in the green sheet that is used as the outermost layer of the laminate and provided with the mounting electrode is formed by machining.
  7. 　前記機械加工としてパンチプレスを実施することを特徴とする、請求項６に記載のセラミック基板の製造方法。 The method for manufacturing a ceramic substrate according to claim 6, wherein a punch press is performed as the machining.
  8. 　前記工程（ｉ）では、前記積層体の前記最表層に用いられる前記グリーンシート以外の前記グリーンシートにおける前記ビアホールをレーザ加工によって形成することを特徴とする、請求項６に記載のセラミック基板の製造方法。 The said process (i) forms the said via hole in the said green sheet other than the said green sheet used for the said outermost layer of the said laminated body by laser processing, The manufacture of the ceramic substrate of Claim 6 characterized by the above-mentioned. Method.
  9. 　請求項６に記載の製造方法で得られるセラミック基板を用いた電気回路モジュールの製造方法であって、
    　（Ｉ）前記セラミック基板のビアと接するように前記焼成体上に実装用電極を形成する工程、
    　（ＩＩ）前記実装用電極上に半田を設けて、該半田の上に電子部品を配置する工程、および
    　（ＩＩＩ）前記セラミック基板、前記電気部品およびそれらの間に介在する前記半田をリフローはんだ付けに付す工程
    を含んで成る、電気回路モジュールの製造方法。     A method for producing an electric circuit module using a ceramic substrate obtained by the production method according to claim 6,
    (I) a step of forming a mounting electrode on the fired body so as to be in contact with the via of the ceramic substrate;
    (II) a step of providing solder on the mounting electrode and disposing an electronic component on the solder; and (III) reflow soldering the ceramic substrate, the electrical component and the solder interposed therebetween. A method for manufacturing an electric circuit module, comprising the step of:
PCT/JP2011/053885 2010-02-18 2011-02-16 Ceramic substrate, electrical circuit module, and method for producing each WO2011102535A1 (en)

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* Cited by examiner, † Cited by third party
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JPH08169776A (en) * 1994-12-19 1996-07-02 Sumitomo Metal Ind Ltd Ceramic multilayer substrate
JP2001068852A (en) * 1999-08-30 2001-03-16 Kyocera Corp Multi-layered wiring board and its manufacture
JP2003198129A (en) * 2001-12-27 2003-07-11 Murata Mfg Co Ltd Method of manufacturing laminated ceramic electronic component

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH08169776A (en) * 1994-12-19 1996-07-02 Sumitomo Metal Ind Ltd Ceramic multilayer substrate
JP2001068852A (en) * 1999-08-30 2001-03-16 Kyocera Corp Multi-layered wiring board and its manufacture
JP2003198129A (en) * 2001-12-27 2003-07-11 Murata Mfg Co Ltd Method of manufacturing laminated ceramic electronic component

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