WO2021005863A1 - Wiring circuit board and method for producing wiring circuit board - Google Patents

Wiring circuit board and method for producing wiring circuit board Download PDF

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Publication number
WO2021005863A1
WO2021005863A1 PCT/JP2020/016550 JP2020016550W WO2021005863A1 WO 2021005863 A1 WO2021005863 A1 WO 2021005863A1 JP 2020016550 W JP2020016550 W JP 2020016550W WO 2021005863 A1 WO2021005863 A1 WO 2021005863A1
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WO
WIPO (PCT)
Prior art keywords
insulating layer
base insulating
photosensitizer
development accelerator
circuit board
Prior art date
Application number
PCT/JP2020/016550
Other languages
French (fr)
Japanese (ja)
Inventor
良介 笹岡
理人 福島
裕紀 ▲桑▼山
Original Assignee
日東電工株式会社
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Application filed by 日東電工株式会社 filed Critical 日東電工株式会社
Priority to CN202080049654.7A priority Critical patent/CN114127141A/en
Publication of WO2021005863A1 publication Critical patent/WO2021005863A1/en

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    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
    • C08F2/00—Processes of polymerisation
    • C08F2/44—Polymerisation in the presence of compounding ingredients, e.g. plasticisers, dyestuffs, fillers
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
    • C08F283/00—Macromolecular compounds obtained by polymerising monomers on to polymers provided for in subclass C08G
    • C08F283/04—Macromolecular compounds obtained by polymerising monomers on to polymers provided for in subclass C08G on to polycarbonamides, polyesteramides or polyimides
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
    • C08G73/00—Macromolecular compounds obtained by reactions forming a linkage containing nitrogen with or without oxygen or carbon in the main chain of the macromolecule, not provided for in groups C08G12/00 - C08G71/00
    • C08G73/06—Polycondensates having nitrogen-containing heterocyclic rings in the main chain of the macromolecule
    • C08G73/10—Polyimides; Polyester-imides; Polyamide-imides; Polyamide acids or similar polyimide precursors
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
    • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
    • G03F7/004—Photosensitive materials
    • G03F7/027—Non-macromolecular photopolymerisable compounds having carbon-to-carbon double bonds, e.g. ethylenic compounds
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
    • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
    • G03F7/004—Photosensitive materials
    • G03F7/027—Non-macromolecular photopolymerisable compounds having carbon-to-carbon double bonds, e.g. ethylenic compounds
    • G03F7/032—Non-macromolecular photopolymerisable compounds having carbon-to-carbon double bonds, e.g. ethylenic compounds with binders
    • G03F7/037—Non-macromolecular photopolymerisable compounds having carbon-to-carbon double bonds, e.g. ethylenic compounds with binders the binders being polyamides or polyimides
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
    • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
    • G03F7/26—Processing photosensitive materials; Apparatus therefor
    • G03F7/40—Treatment after imagewise removal, e.g. baking
    • 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
    • H05K1/03—Use of materials for the substrate
    • 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
    • H05K3/10—Apparatus or processes for manufacturing printed circuits in which conductive material is applied to the insulating support in such a manner as to form the desired conductive pattern
    • H05K3/18—Apparatus or processes for manufacturing printed circuits in which conductive material is applied to the insulating support in such a manner as to form the desired conductive pattern using precipitation techniques to apply the conductive material

Definitions

  • the present invention relates to a wiring circuit board and a method for manufacturing a wiring circuit board.
  • a base insulating layer having an image sensor opening, a conductor pattern having an image sensor connecting terminal, and a cover insulating layer are provided in this order, and the image sensor connecting terminal is exposed from the image sensor opening to cover the base insulating layer.
  • An image sensor mounting substrate that is arranged so as to be flush with the surface opposite to the insulating layer has been proposed (see, for example, Patent Document 1).
  • the terminal of the image sensor and the image sensor connection terminal are connected by solder bumps on the surface of the base insulating layer opposite to the cover insulating layer, and the image sensor is mounted.
  • a varnish of a photosensitive insulating material is applied onto a metal support and dried to form a base film, which is then exposed and developed into a predetermined pattern. , If necessary, heat-cured to form a base insulating layer.
  • a polyimide precursor composition containing a polyimide precursor, an imide acrylate compound as a development accelerator, and a pyridine-based photosensitive agent has been proposed (for example, Patent Documents). See 2.).
  • the base insulating layer is formed from the polyimide precursor composition described in Patent Document 2, the adhesion of the underfill layer to the base insulating layer is lowered under moist heat conditions, and the underfill layer is used for base insulation. May peel off from the layer.
  • the image sensor mounted on the image sensor mounting substrate may be removed and reworked for replacement or reuse.
  • the adhesion between the base insulating layer and the underfill layer is excessively high, it becomes difficult to peel off the underfill layer from the base insulating layer, and there is a problem that the reworkability of the image sensor cannot be ensured.
  • the present invention manufactures a wiring circuit board capable of ensuring reworkability of electronic components while suppressing a decrease in adhesion of the second insulating layer to the first insulating layer under moist heat conditions, and a wiring circuit board having high manufacturing efficiency. Provide a method.
  • the present invention [1] includes a first insulating layer containing a polyimide, a development accelerator, and a photosensitizer, and terminals arranged on one surface of the first insulating layer in the thickness direction.
  • the sum of the content ratio of the development accelerator and the content ratio of the photosensitizer in one insulating layer includes a wiring circuit board of 5 ppm or more and 50 ppm or less.
  • the sum of the content ratio of the development accelerator and the content ratio of the photosensitizer in the first insulating layer is equal to or more than the above lower limit, so that the electronic component is placed on one surface in the thickness direction of the first insulating layer. Even if the wiring circuit board is placed under moist heat conditions with the second insulating layer provided between the first insulating layer and the electronic component after mounting, the adhesion of the second insulating layer to the first insulating layer is reduced. Can be suppressed.
  • the total of the content ratio of the development accelerator and the content ratio of the photosensitizer in the first insulating layer is not more than the above upper limit.
  • the adhesion of the second insulating layer to the first insulating layer can be adjusted so that the second insulating layer can be peeled off from the first insulating layer, and the reworkability of the electronic component can be ensured.
  • the present invention [2] includes the wiring circuit board according to the above [1], wherein the development accelerator contains an imide acrylate compound and / or a polyethylene glycol compound.
  • the development accelerator contains an imide acrylate compound and / or a polyethylene glycol compound
  • the total of the content ratio of the development accelerator and the content ratio of the photosensitizer in the first insulating layer is adjusted to the above range. While being possible, the photosensitivity of the varnish containing the polyimide precursor, the development accelerator, and the photosensitizer can be ensured.
  • the present invention [3] includes a step of preparing a metal support layer, a step of forming a first insulating layer containing a polyimide, a photosensitizer, and a development accelerator on the metal support layer, and the first step.
  • the step of forming the first insulating layer includes a step of forming a terminal on one surface of the insulating layer in the thickness direction, and the step of forming the first insulating layer includes a polyimide precursor, a photosensitizer, and a development accelerator on the metal support layer.
  • a wiring circuit board including a step of applying a varnish containing the above, a step of exposing and developing the varnish, and a step of heating the developed varnish to 300 ° C. or higher and 400 ° C. or lower for 100 minutes or longer. Including the manufacturing method of.
  • the developed varnish is heated to 300 ° C. or higher and 400 ° C. or lower for 100 minutes or longer. Therefore, the sum of the content ratio of the photosensitive agent and the content ratio of the development accelerator in the first insulating layer is 5 ppm. It can be adjusted to 50 ppm or less. As a result, the above-mentioned wiring circuit board can be efficiently manufactured even though it is a simple method.
  • the wiring circuit board of the present invention it is possible to ensure reworkability of electronic components while suppressing a decrease in adhesion of the second insulating layer to the first insulating layer under moist heat conditions.
  • the above-mentioned wiring circuit board can be efficiently manufactured.
  • FIG. 1 shows a plan view of an image pickup device mounting board according to an embodiment of the wiring circuit board of the present invention.
  • FIG. 2 shows a cross-sectional view taken along the line AA of the image sensor mounting substrate shown in FIG. 3A to 3D show a manufacturing process diagram of the image pickup device mounting substrate shown in FIG. 2,
  • FIG. 3A is a metal support preparation step and a base insulating layer forming step
  • FIG. 3B is a conductor pattern forming step
  • FIG. 3C is.
  • FIG. 3D shows a metal support removing step.
  • 4E and 4F show a process diagram of mounting the image pickup device on the image pickup device mounting substrate following FIG. 3D
  • FIG. 4E shows the element connection step
  • FIG. 4F shows the underfill forming step.
  • FIG. 5 shows an image pickup apparatus including the image pickup device mounting substrate shown in FIG.
  • mounting board 1 As an embodiment of the wiring circuit board of the present invention will be described.
  • the mounting board 1 is a flexible wiring circuit board (FPC) for mounting an image pickup device 21 (see FIG. 4F described later) as an example of an electronic component, and is still provided with the image pickup device 21. Not done.
  • the mounting substrate 1 has a flat plate shape (sheet shape) that is substantially rectangular (rectangular) in a plan view.
  • the mounting board 1 includes a housing arrangement portion 2 and an external component connection portion 3.
  • the housing arrangement portion 2 is a portion in which the housing 22 (described later, see FIG. 5) and the image sensor 21 are arranged. Specifically, the housing arrangement portion 2 is a portion that overlaps with the housing 22 when the housing 22 is arranged on the mounting substrate 1 and projected in the thickness direction of the mounting substrate 1. A plurality of first terminals 10 (described later) as an example of terminals are arranged substantially in the center of the housing arrangement portion 2.
  • the external component connecting portion 3 is an area other than the housing arranging portion 2 and is a portion for connecting to the external component.
  • the external component connecting portion 3 is arranged continuously with the housing arranging portion 2 in the longitudinal direction of the mounting board 1.
  • a plurality of second terminals 11 (described later) are arranged in the external component connecting portion 3.
  • the mounting substrate 1 includes a base insulating layer 4 as an example of the first insulating layer, a conductor pattern 5, and a cover insulating layer 6 in order in the thickness direction of the base insulating layer 4.
  • the thickness direction of the base insulating layer 4 is simply described as the thickness direction.
  • the upper side of the paper surface is one side in the thickness direction of the base insulating layer 4, and the lower side of the paper surface is the other side in the thickness direction of the base insulating layer 4.
  • the base insulating layer 4 has the outer shape of the mounting substrate 1 and has a substantially rectangular shape in a plan view.
  • the base insulating layer 4 is not supported by the metal support 19 (see FIGS. 3A to 3C) described later, and the mounting substrate 1 does not include the metal support 19 (metal support layer).
  • the base insulating layer 4 includes a plurality of first openings 7 and a plurality of second openings 8.
  • the plurality of first openings 7 expose the first terminal 10 (described later) from one side in the thickness direction.
  • the plurality of first openings 7 are arranged in a central portion of the housing arrangement portion 2 so as to form a rectangular frame at intervals of each other.
  • the first opening 7 penetrates the base insulating layer 4 in the thickness direction and has a substantially circular shape in a plan view.
  • the first opening 7 has a tapered shape in which the cross-sectional area of the opening decreases toward one side in the thickness direction (see FIG. 2).
  • the plurality of second openings 8 expose the second terminal 11 (described later) from one side in the thickness direction.
  • the plurality of second openings 8 are arranged in the external component connecting portion 3 so as to be spaced apart from each other in the width direction of the mounting substrate 1.
  • the second opening 8 penetrates the base insulating layer 4 in the thickness direction and has a substantially rectangular shape (rectangular shape) in a plan view.
  • the base insulating layer 4 includes one surface 4A and the other surface 4B in the thickness direction.
  • One side 4A of the base insulating layer is located on one side in the thickness direction.
  • One surface 4A of the base insulating layer has a flat (smooth) shape, and the entire surface thereof is exposed.
  • the other surface 4B of the base insulating layer is located on the other side in the thickness direction and is located on the opposite side of the one surface 4A in the thickness direction.
  • the other surface 4B of the base insulating layer is covered with the cover insulating layer 6.
  • Such a base insulating layer 4 contains a polyimide, a development accelerator, and a photosensitizer.
  • the polyimide is, for example, the polyimide described in JP-A-2018-190787 and contains a reaction product (cured product) of an acid dianhydride component and a diamine component. More specifically, polyimide is prepared by imidizing polyamic acid, which is a reaction product of an acid dianhydride component and a diamine component.
  • the acid dianhydride component examples include aromatic dianhydrides (for example, 3,3', 4,4'-biphenyltetracarboxylic dianhydride (BPDA)) described in JP-A-2018-190787. (Biphenyltetracarboxylic dianhydride, etc.), and aliphatic acid dianhydride, etc.
  • aromatic dianhydrides for example, 3,3', 4,4'-biphenyltetracarboxylic dianhydride (BPDA) described in JP-A-2018-190787.
  • BPDA 4,4'-biphenyltetracarboxylic dianhydride
  • aliphatic acid dianhydride etc.
  • the acid dianhydride component can be used alone or in combination of two or more.
  • the acid dianhydride component preferably contains an aromatic acid dianhydride, and more preferably contains 3,3', 4,4'-biphenyltetracarboxylic dianhydride (BPDA).
  • the acid dianhydride component is preferably composed of aromatic acid dianhydride (3,3', 4,4'-biphenyltetracarboxylic dianhydride).
  • diamine component examples include aromatic diamines and aliphatic diamines described in JP-A-2018-190787.
  • the acid dianhydride component can be used alone or in combination of two or more.
  • the diamine component preferably contains an aromatic diamine, and more preferably consists of an aromatic diamine.
  • aromatic diamine examples include phenylenediamine such as p-phenylenediamine (PPD).
  • aromatic diamine is also included.
  • aromatic diamine is represented by, for example, the following general formula (1).
  • R 1 is a hydrogen atom or a substituent.
  • the amino group is bonded to the meta position or the para position with respect to the bond between the benzene rings. .
  • substituents represented by R 1 in the general formula (1) for example, an alkyl group having 3 or less carbon atoms such as a methyl group, for example, a trifluoromethyl group, perfluoroethyl group, carbon atoms, such as perfluoro propyl
  • substituents represented by R 1 in the general formula (1) for example, an alkyl group having 3 or less carbon atoms such as a methyl group, for example, a trifluoromethyl group, perfluoroethyl group, carbon atoms, such as perfluoro propyl
  • substituents represented by R 1 in the general formula (1) for example, an alkyl group having 3 or less carbon atoms such as a methyl group, for example, a trifluoromethyl group, perfluoroethyl group, carbon
  • R 1 preferably represents a substituent, more preferably a haloalkyl group, particularly preferably a fluoroalkyl group, and particularly preferably a trifluoromethyl group.
  • aromatic diamine represented by the above general formula (1) examples include 2,2'-ditrifluoromethyl-4,4'-diaminobiphenyl (also known as 2,2'-bis (trifluoromethyl)-. 4,4'-diaminobiphenyl, TFMB) and the like.
  • Such an aromatic diamine preferably contains a combination of phenylenediamine and the aromatic diamine represented by the general formula (1), and more preferably phenylenediamine and R 1 in the general formula (1).
  • the content ratio of the aromatic diamine represented by the general formula (1) is, for example, 15 mol% or more, preferably 20 mol% or more, for example, 80 mol% or less, preferably 50 mol% or less. is there.
  • the acid dianhydride component contains 3,3', 4,4'-biphenyltetracarboxylic dianhydride (BPDA), and the diamine component is phenylenediamine (PPD) and 2,2'-ditrifluoromethyl.
  • BPDA 4,4'-biphenyltetracarboxylic dianhydride
  • PPD phenylenediamine
  • TFMB 2,2'-ditrifluoromethyl
  • the polyimide contains a structural unit A represented by the following general formula (2) and a structural unit B represented by the following general formula (3).
  • the mol ratio (structural unit A / structural unit B) of the structural unit A represented by the general formula (1) and the structural unit B represented by the general formula (2) is, for example, 15. / 85 to 80/20, preferably 20/80 to 50/50.
  • the development accelerator contains, for example, an imide acrylate compound and / or a polyethylene glycol compound.
  • the imide acrylate compound includes, for example, the imide acrylate compound described in JP2013-100441A.
  • the imide acrylate compound is represented by the following general formula (4).
  • R 2 represents a hydrogen atom or a methyl group.
  • R 3 represents a divalent hydrocarbon group having 2 or more carbon atoms.
  • R 2 preferably represents a hydrogen atom.
  • R 3 preferably represents an alkylene group having 2 or more carbon atoms, and more preferably an ethylene group.
  • imide acrylate compound represented by the general formula (4) examples include n-acryloyloxyethyl hexahydrophthalimide and the like.
  • the polyethylene glycol compound includes, for example, the polyethylene glycol compound described in Japanese Patent Application Laid-Open No. 2013-100441.
  • polyethylene glycol compound is represented by the following general formula (5).
  • R 4 represents a hydroxyl group or a methoxy group.
  • R 5 represents a hydrogen atom or a methyl group.
  • B represents a natural number of 4 to 23.
  • a hydroxyl group (R 4 ) and a hydrogen atom (R 5 ) as a combination of R 4 and R 5 , a hydroxyl group (R 4 ) and a hydrogen atom (R 5 ), a hydroxyl group (R 4 ) and a methyl group (R 5 ), and a methoxy group (R) 4 ) and a methyl group (R 5 ), preferably a hydroxyl group (R 4 ) and a hydrogen atom (R 5 ).
  • the number average molecular weight (Mn) of the polyethylene glycol compound represented by the general formula (5) is, for example, 200 or more, for example, 1000 or less, preferably 400 or less.
  • the number average molecular weight can be measured by gel permeation chromatography (GPC) method and can be calculated in terms of polyethylene oxide.
  • Such a development accelerator preferably comprises an imide acrylate compound represented by the above general formula (4).
  • the photosensitizer includes, for example, a pyridine-based photosensitizer described in Japanese Patent Application Laid-Open No. 2013-100441.
  • the pyridine-based photosensitizer is represented by the following general formula (6).
  • R 6 to R 10 represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. R 6 to R 10 may be the same or different from each other.
  • each of R 6 and R 7 preferably represents a hydrogen atom or a methyl group, and more preferably a hydrogen atom.
  • R 8 preferably represents an alkyl group having 1 to 4 carbon atoms, more preferably a methyl group or an ethyl group, and particularly preferably an ethyl group.
  • each of R 9 and R 10 preferably represents an alkyl group having 1 to 4 carbon atoms, more preferably a methyl group or an ethyl group, and particularly preferably a methyl group. Shown.
  • pyridine-based photosensitizer represented by the general formula (6) include 1-ethyl-3,5-dimethoxycarbonyl-4- (2-nitrophenyl) -1,4-dihydropyridine. Can be mentioned.
  • the total (mass ratio) of the content ratio of the photosensitizer and the content ratio of the development accelerator in the base insulating layer 4 is 5 ppm or more and 50 ppm or less.
  • the total of the content ratio of the photosensitizer and the content ratio of the development accelerator can be measured by TOF-SIMS (the same applies hereinafter).
  • the adhesion of the underfill layer 18 (described later) to the base insulating layer 4 is determined by the underfill layer 18 (described later). It can be adjusted so that it can be peeled off from the layer 4, and the reworkability of the image pickup device 21 can be ensured. Further, when the sum of the content ratio of the photosensitizer and the content ratio of the development accelerator is not more than the above upper limit, it is possible to suppress a decrease in the adhesion of the underfill layer 18 (described later) to the base insulating layer 4 under moist heat conditions.
  • the base insulating layer 4 can further contain a known additive.
  • known additives include, for example, sensitizers, polymerization inhibitors, chain transfer agents, leveling agents, plasticizers, surfactants, defoamers and the like.
  • the content ratio of the known additive in the base insulating layer 4 is, for example, 15% by mass or less, preferably 10% by mass or less.
  • the thickness of the base insulating layer 4 is, for example, 1 ⁇ m or more, preferably 3 ⁇ m or more, for example, 30 ⁇ m or less, preferably 12 ⁇ m or less, and more preferably 8 ⁇ m or less.
  • the conductor pattern 5 includes a plurality of first terminals 10, a plurality of second terminals 11 (see FIG. 1), and a plurality of wirings 9.
  • the plurality of first terminals 10 are arranged and arranged at the center of the housing arrangement portion 2 so as to form a rectangular frame at intervals from each other (see FIG. 1).
  • the plurality of first terminals 10 are provided so as to correspond to the plurality of terminals 25 (see FIG. 4E) of the mounted image sensor 21. Further, the plurality of first terminals 10 are provided corresponding to the plurality of first openings 7.
  • the first terminal 10 has a substantially circular shape in a plan view.
  • the first terminal 10 is filled in the first opening 7 and is exposed from the base insulating layer 4 when viewed from one side in the thickness direction.
  • One surface 10A of the first terminal 10 in the thickness direction has a flat (smooth) shape.
  • One surface 10A of the first terminal 10 in the thickness direction is substantially flush with one surface 4A of the base insulating layer 4.
  • the first terminal 10 is arranged on one surface 4A of the base insulating layer 4.
  • the plurality of second terminals 11 are aligned and arranged at the external component connecting portion 3 at intervals from each other.
  • the plurality of second terminals 11 are provided so as to correspond to a plurality of terminals (not shown) of the external component. Further, the plurality of second terminals 11 are provided corresponding to the plurality of second openings 8.
  • the second terminal 11 has a substantially rectangular shape (rectangular shape) in a plan view.
  • the second terminal 11 is filled in the second opening 8 and is exposed from the base insulating layer 4 when viewed from one side in the thickness direction.
  • One surface of the second terminal 11 in the thickness direction is substantially flush with one surface 4A of the base insulating layer 4.
  • the second terminal 11 is arranged on one surface 4A of the base insulating layer 4.
  • the plurality of wirings 9 are arranged on the other side in the thickness direction with respect to the base insulating layer 4, and specifically, are arranged on the other surface 4B of the base insulating layer 4.
  • the plurality of wirings 9 electrically connect the plurality of first terminals 10 and the plurality of second terminals 11. Specifically, one end of each wiring 9 falls from the other surface 4B into the first opening 7 and is continuous with each first terminal 10. The other end of each wiring 9 falls from the other surface 4B into the second opening 8 and is continuous with each second terminal 11.
  • Examples of the material of the conductor pattern 5 include metal materials such as copper, silver, gold, nickel or alloys containing them, and solder, and copper is preferable.
  • the thickness of the conductor pattern 5 is, for example, 1 ⁇ m or more, preferably 2 ⁇ m or more, for example, 15 ⁇ m or less, preferably 10 ⁇ m or less.
  • the cover insulating layer 6 is arranged on the other side in the thickness direction with respect to the base insulating layer 4 so as to cover the conductor pattern 5, and specifically, is arranged on the other surface 4B of the base insulating layer 4.
  • the outer shape of the cover insulating layer 6 is formed to be the same as the outer shape of the base insulating layer 4.
  • Examples of the material of the cover insulating layer 6 include an insulating material.
  • Examples of the insulating material include synthetic resins such as polyimide, polyamideimide, acrylic, polyethernitrile, polyether sulfone, polyethylene terephthalate, polyethylene naphthalate, and polyvinyl chloride.
  • the insulating material preferably, the same polyimide as the base insulating layer 4 can be mentioned.
  • the thickness of the cover insulating layer 6 is, for example, 1 ⁇ m or more, preferably 2 ⁇ m or more, for example, 30 ⁇ m or less, preferably 10 ⁇ m or less, and more preferably 5 ⁇ m or less.
  • the thickness of such a mounting substrate 1 (the sum of the thicknesses of the base insulating layer 4, the conductor pattern 5, and the cover insulating layer 6) is, for example, 3 ⁇ m or more, for example, 50 ⁇ m or less, preferably 30 ⁇ m or less.
  • the method for manufacturing the mounting substrate 1 includes, for example, a metal support preparation step, a base insulating layer forming step, a conductor pattern forming step, and a cover insulating layer forming step in this order.
  • the metal support 19 as an example of the metal support layer is prepared.
  • the metal support 19 has a flat plate shape that is substantially rectangular (rectangular) in a plan view.
  • the upper surface of the metal support 19 has a flat (smooth) shape.
  • Examples of the material of the metal support 19 include metal materials such as stainless steel, 42 alloy, and aluminum, and preferably stainless steel.
  • the thickness of the metal support 19 is, for example, 5 ⁇ m or more, preferably 10 ⁇ m or more, and for example, 50 ⁇ m or less, preferably 30 ⁇ m or less.
  • the base insulating layer 4 containing the above-mentioned polyimide, the above-mentioned development accelerator, and the above-mentioned photosensitizer is formed on the upper surface of the metal support 19.
  • the thickness direction of the base insulating layer 4 shown in FIGS. 3A to 3D is opposite to the thickness direction of the base insulating layer 4 shown in FIG. 2, with the upper side of the paper surface being the other side in the thickness direction and the lower side of the paper surface being one side in the thickness direction.
  • one surface 4A of the base insulating layer 4 comes into contact with the metal support 19, and the other surface 4B of the base insulating layer 4 is located on the opposite side of the metal support 19 with respect to the one surface 4A.
  • the base insulating layer forming step includes a step of applying a varnish as a material of the base insulating layer 4 on the metal support 19, a step of exposing and developing the applied varnish, and a step of heating the developed varnish. Including the process of
  • the varnish contains a polyamic acid as an example of a polyimide precursor, the above-mentioned development accelerator, and the above-mentioned photosensitizer.
  • Polyamic acid is a reaction product of the above-mentioned acid dianhydride component and the above-mentioned diamine component.
  • the above-mentioned acid dianhydride component and the above-mentioned diamine component are reacted in the presence of an organic solvent, for example, under the conditions of 15 ° C. or higher and 40 ° C. or lower, 0.2 hours or longer and 72 hours or lower. This prepares the polyamic acid.
  • the organic solvent can dissolve the above-mentioned acid dianhydride component and the above-mentioned diamine component.
  • examples of the organic solvent include polar aprotons such as N-methylpyrrolidone, dimethylformamide, dimethyl sulfoxide, acetonitrile and the like.
  • the organic solvent can be used alone or in combination of two or more.
  • organic solvents polar aprotons are preferable, and N-methylpyrrolidone is more preferable.
  • the content ratio of the organic solvent can be changed as appropriate.
  • the content ratio of the development accelerator in the varnish is, for example, 30 parts by mass or more and 100 parts by mass or less with respect to 100 parts by mass of polyamic acid.
  • the content ratio of the photosensitizer in the varnish is, for example, 10 parts by mass or more and 55 parts by mass or less with respect to 100 parts by mass of polyamic acid.
  • the varnish is applied to the entire upper surface of the metal support 19 and dried. As a result, the organic solvent volatilizes and a base film is formed.
  • the base film is exposed through a photomask having a pattern corresponding to the openings (first opening 7 and second opening 8). Then, the base film is developed.
  • the developed base film is heated and cured.
  • the heating temperature is 300 ° C. or higher, preferably 330 ° C. or higher, 400 ° C. or lower, preferably 380 ° C. or lower.
  • the heating time is 100 minutes or more, preferably 110 minutes or more, more preferably 120 minutes or more, for example, 500 minutes or less, preferably 400 minutes or less, still more preferably 350 minutes or less.
  • the heating temperature is equal to or higher than the above lower limit and the heating time is equal to or higher than the above lower limit, the polyamic acid is imidized to form a polyimide, and most of the above-mentioned development accelerator and photosensitizer are removed. Therefore, the total of the content ratio of the development accelerator and the content ratio of the photosensitizer in the base insulating layer 4 can be adjusted to be equal to or less than the above upper limit. Further, when the heating temperature is not more than the above upper limit, the sum of the content ratio of the development accelerator and the content ratio of the photosensitizer in the base insulating layer 4 can be secured to be more than the above lower limit.
  • the base insulating layer 4 containing polyimide is formed on the metal support 19.
  • the conductor pattern 5 is formed in the above-mentioned pattern with the upper surface (the other surface 4B) of the base insulating layer 4 and the first opening 7 and the second opening 8. It is formed on the upper surface of the metal support 19 exposed from, for example, by an additive method or the like.
  • the plurality of first terminals 10, the plurality of second terminals 11, and the plurality of wirings 9 are collectively formed.
  • the first terminal 10 is arranged in the first opening 7 and comes into contact with the upper surface of the metal support 19.
  • the second terminal 11 is arranged in the second opening 8 and comes into contact with the upper surface of the metal support 19.
  • the first terminal 10 and the second terminal 11 are arranged on one surface 4A of the base insulating layer 4.
  • the wiring 9 is arranged on the other surface 4B of the base insulating layer 4.
  • the cover insulating layer 6 is formed on the upper surface (the other surface 4B) of the base insulating layer 4 so as to cover the conductor pattern 5.
  • the cover insulating layer forming step can be carried out in the same manner as the base insulating layer forming step.
  • the metal support 19 is removed in the metal support removing step.
  • a method for removing the metal support 19 for example, a method of peeling the metal support 19 from the lower surface (one surface 4A) of the base insulating layer 4, for example, etching the metal support 19 (for example, dry etching, wet etching, etc.). How to do it.
  • etching is preferable, and wet etching is more preferable.
  • the metal support 19 When the metal support 19 is wet-etched, for example, a ferric chloride solution is used as the etching solution. Then, for example, the metal support 19 is removed by spraying the etching solution from one side in the thickness direction with respect to the metal support 19.
  • a ferric chloride solution is used as the etching solution.
  • one surface 4A of the base insulating layer 4, one surface 10A of the first terminal 10, and one surface (not shown) of the second terminal 11 are exposed.
  • the mounting substrate 1 including the base insulating layer 4, the conductor pattern 5, and the cover insulating layer 6 is manufactured.
  • Such a mounting board 1 is provided with, for example, an image pickup device such as a camera module on which an image pickup device is mounted.
  • the method of mounting the image pickup device 21 on the mounting board 1 includes an element connection step and an underfill forming step.
  • the image sensor 21 is prepared.
  • the image sensor 21 is a semiconductor element that converts light into an electric signal, and examples thereof include solid-state image sensors such as CMOS sensors and CCD sensors.
  • the image pickup device 21 is formed in a flat plate shape having a substantially rectangular shape in a plan view, and includes silicon such as a Si substrate, a photodiode (photoelectric conversion element) arranged on the silicon substrate, and a color filter (not shown).
  • the image sensor 21 includes a plurality of terminals 25.
  • the plurality of terminals 25 correspond to the plurality of first terminals 10.
  • a bonding material 26 such as a solder bump is arranged on the first terminal 10 of the mounting board 1, and the first terminal 10 of the mounting board 1 and the terminal 25 of the image sensor 21 are electrically connected via the bonding material 26. Connecting.
  • the image sensor 21 is arranged at the center of the housing arrangement portion 2 of the mounting substrate 1, and is flip-chip mounted on the mounting substrate 1. At this time, the image pickup device 21 is located on one side in the thickness direction with a distance from the one side surface 4A of the base insulating layer 4.
  • an underfill layer 18 as an example of the second insulating layer is formed between the image pickup device 21 and the base insulating layer 4.
  • a liquid resin composition is injected between the image pickup device 21 and one surface 4A of the base insulating layer 4, and then heat-cured.
  • Examples of the material of the underfill layer 18 include resin materials such as epoxy resin, polyurethane resin, silicone resin, and polyester resin, and epoxy resin is preferable.
  • the material of the underfill layer 18 can be used alone or in combination of two or more.
  • the heating temperature is appropriately changed depending on the material of the underfill layer 18, but is, for example, 100 ° C. or higher, preferably 120 ° C. or higher, for example, 150 ° C. or lower, preferably 130 ° C. or lower.
  • the heating time is appropriately changed depending on the material of the underfill layer 18, but is, for example, 10 minutes or more, preferably 30 minutes or more, for example, 120 minutes or less, preferably 60 minutes or less.
  • the underfill layer 18 is formed between the image pickup device 21 and the one surface 4A of the base insulating layer 4.
  • the underfill layer 18 is arranged on one surface 4A of the base insulating layer 4. That is, the mounting substrate 1 on which the image pickup device 21 is mounted includes the underfill layer 18.
  • the mounting substrate 1, the image sensor 21, and the underfill layer 18 form an image pickup unit 27.
  • the mounting substrate 1 is not an image pickup device described later, but a component of the image pickup device, that is, a component for manufacturing the image pickup device, and is an industrially applicable device.
  • the mounting substrate 1 may be distributed as a single component that does not include an image sensor, or may be distributed as an image pickup unit on which an image sensor is mounted.
  • Imaging Device Next, an imaging device 20 including an imaging unit 27 will be described with reference to FIG.
  • the image pickup device 20 includes an image pickup unit 27, a housing 22, an optical lens 23, and a filter 24.
  • the image pickup unit 27 includes a mounting substrate 1, an image pickup element 21, and an underfill layer 18.
  • the housing 22 is arranged in the housing arrangement portion 2 of the mounting substrate 1 so as to surround the housing 22 with a distance from the image sensor 21.
  • the housing 22 has a tubular shape having a substantially rectangular shape in a plan view.
  • the optical lens 23 is arranged on the opposite side of the mounting substrate 1 with respect to the image pickup element 21 at intervals in the thickness direction.
  • the optical lens 23 is formed in a substantially circular shape in a plan view, and is fixed to the housing 22 so that light from the outside reaches the image pickup device 21.
  • the filter 24 is arranged between the image sensor 21 and the optical lens 23 in the thickness direction at intervals from the image sensor 21, and is fixed to the housing 22.
  • the present inventors under the base insulating layer 4 when the imaging device 20 (imaging unit 27) is placed under moist heat conditions (for example, 100 ° C. or higher and relative humidity 80% or higher). It was found that the adhesion of the fill layer 18 is reduced.
  • moist heat conditions for example, 100 ° C. or higher and relative humidity 80% or higher.
  • the present inventors have examined various findings, and the decrease in the adhesion of the underfill layer 18 under moist heat conditions is the sum of the content ratio of the development accelerator and the content ratio of the photosensitizer in the base insulating layer 4.
  • the present invention was completed by finding that it depends on.
  • the sum of the content ratio of the development accelerator and the content ratio of the photosensitizer in the base insulating layer 4 is equal to or higher than the above lower limit. Therefore, even when the image pickup apparatus 20 (imaging unit 27) is placed under moist heat conditions, it is possible to suppress a decrease in the adhesion of the underfill layer 18 to the base insulating layer 4.
  • the total of the content ratio of the development accelerator and the content ratio of the photosensitizer in the base insulating layer 4 is not more than the above upper limit. Therefore, when the image pickup device 21 mounted on the mounting board 1 is removed from the mounting board 1 and reworked, the underfill layer 18 can be peeled off from the base insulating layer 4. As a result, the reworkability of the image sensor 21 can be ensured.
  • the development accelerator also contains an imide acrylate compound and / or a polyethylene glycol compound. Therefore, while the sum of the content ratio of the development accelerator and the content ratio of the photosensitizer in the base insulating layer 4 can be adjusted within the above range, the photosensitivity of the varnish containing the polyimide precursor, the development accelerator, and the photosensitizer Can be secured.
  • a varnish containing a polyimide precursor, a development accelerator, and a photosensitizer is applied onto the metal support 19, and then the varnish is used.
  • the (base coating) is exposed and developed, and then the varnish (base coating) is heated to the above heating temperature and the above heating time to form the base insulating layer 4.
  • the total of the content ratio of the development accelerator and the content ratio of the photosensitizer in the base insulating layer 4 can be adjusted within the above range.
  • the above-mentioned mounting substrate 1 can be efficiently manufactured by a simple method.
  • the image pickup device mounting board 1 (mounting board 1) for mounting the image pickup device 21 is described as the wiring circuit board of the present invention, but the application of the wiring circuit board is not limited to this. ..
  • it is suitably used for FPCs used in smartphones, personal computers, game machines, and the like.
  • the mounting substrate 1 layers adjacent to each other in the thickness direction are adhesive-less FPCs that are adhered without an adhesive, but the present invention is not limited to this.
  • An adhesive layer may be provided between layers adjacent to each other in the thickness direction.
  • the mounting substrate 1 is an adhesive-less FPC as in the above embodiment.
  • the mounting board 1 includes a base insulating layer 4, a conductor pattern 5, and a cover insulating layer 6, but the configuration of the mounting board 1 is not limited to this.
  • the mounting substrate 1 may be further provided with a shield layer that is arranged on one side of the cover insulating layer 6 in the thickness direction and blocks electromagnetic waves from the outside, and a second cover insulating layer that covers the shield layer.
  • the image pickup element 21 is flip-chip mounted on the mounting board 1, but can also be mounted on the mounting board 1 by wire bonding.
  • a reference example and a reference comparative example are shown below, and the present invention will be described in more detail.
  • the present invention is not limited to Reference Examples and Reference Comparative Examples.
  • specific numerical values such as the compounding ratio (content ratio), physical property values, and parameters used in the following description are described in the above-mentioned "Form for carrying out the invention", and the compounding ratios corresponding to them ( Substitute for the upper limit (numerical value defined as "less than or equal to” or “less than”) or lower limit (numerical value defined as "greater than or equal to” or “excess”) such as content ratio), physical property value, parameter, etc. it can.
  • Reference Examples 1 and 2 and Reference Comparative Example 1 A metal support made of stainless steel is prepared, the varnish prepared in Production Example 1 is applied to the upper surface of the metal support, and then dried at 80 ° C. for 10 minutes to form a base film (polyimide precursor film). Formed.
  • the base film was exposed and developed, and then cured under a nitrogen atmosphere at the heating temperature and heating time shown in Table 1. As a result, a base insulating layer containing polyimide was formed.
  • the metal support was removed by spraying an aqueous solution of ferric chloride (etching solution) on the metal support. As a result, one side of the base insulating layer was exposed.
  • etching solution aqueous solution of ferric chloride
  • Kapton 100H (manufactured by DuPont) was prepared as a base insulating layer. Kapton 100H did not contain a development accelerator and a photosensitizer.
  • a liquid epoxy resin composition was applied to one surface of the base insulating layer after the PCT test, and then dried at 125 ° C. for 10 minutes to form an underfill layer.
  • the thickness of the underfill layer was about 40 ⁇ m.
  • a double-sided tape (No. 5000ns, manufactured by Nitto Denko Corporation) was attached to the surface of the underfill layer opposite to the base insulating layer to prepare a laminate.
  • the laminate includes a base insulating layer, an underfill layer, and double-sided tape in this order in the thickness direction.
  • the laminate was cut into a flat band having a width of 5 mm, and the laminate was fixed to the sample table provided with the following device with double-sided tape.
  • the sample table had a cylindrical shape that was rotatably supported, and the outer diameter of the sample table was 20 cm. Further, the laminated body was adhered to the peripheral surface of the sample table.
  • the total of the content ratio of the development accelerator and the content ratio of the photosensitizer in the base insulating layer is 5 ppm or more, and the initial adhesion of the underfill layer to the base insulating layer is 200 gf / cm or less. It has been adjusted. If the adhesion exceeds 200 gf / cm as in Reference Comparative Example 2, it is difficult to peel off the underfill layer from the base insulating layer when the electronic component is reworked. In this respect, in Reference Example 1, the adhesion is 100 gf / cm or less, and the reworkability of the electronic component can be ensured.
  • the wiring circuit board of the present invention is used in various applications such as an image sensor mounting board, a flexible wiring circuit board used in a smartphone, a personal computer, a game machine, and the like.

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Abstract

A mounting board 1 is equipped with a base insulation layer 4 containing a polyimide, a development accelerator, and a photosensitizer and a first terminal 10 arranged on one surface 4A of the base insulation layer 4. The sum of the content of development accelerator and the content of photosensitizer in the base insulation layer 4 is adjusted to 5-50 ppm.

Description

配線回路基板および配線回路基板の製造方法Wiring circuit board and manufacturing method of wiring circuit board
　本発明は、配線回路基板および配線回路基板の製造方法に関する。 The present invention relates to a wiring circuit board and a method for manufacturing a wiring circuit board.
　従来、撮像素子などの電子部品が実装される配線回路基板が知られている。 Conventionally, a wiring circuit board on which electronic components such as an image sensor are mounted is known.
　例えば、撮像素子開口部を有するベース絶縁層と、撮像素子接続端子を有する導体パターンと、カバー絶縁層とを順に備え、撮像素子接続端子が、撮像素子開口部から露出され、ベース絶縁層におけるカバー絶縁層と反対側の表面と面一となるように配置される撮像素子実装基板が提案されている（例えば、特許文献１参照。）。 For example, a base insulating layer having an image sensor opening, a conductor pattern having an image sensor connecting terminal, and a cover insulating layer are provided in this order, and the image sensor connecting terminal is exposed from the image sensor opening to cover the base insulating layer. An image sensor mounting substrate that is arranged so as to be flush with the surface opposite to the insulating layer has been proposed (see, for example, Patent Document 1).
　そのような撮像素子実装基板には、ベース絶縁層におけるカバー絶縁層と反対側の表面において、撮像素子の端子と撮像素子接続端子とがソルダーバンプにより接続されて、撮像素子が実装される。 On such an image sensor mounting substrate, the terminal of the image sensor and the image sensor connection terminal are connected by solder bumps on the surface of the base insulating layer opposite to the cover insulating layer, and the image sensor is mounted.
　また、そのような撮像素子実装基板を製造するには、まず、感光性の絶縁材料のワニスを、金属支持体上に塗布し乾燥させてベース皮膜を形成し、所定のパターンに露光および現像し、必要に応じて加熱硬化させて、ベース絶縁層を形成する。 Further, in order to manufacture such an image sensor mounting substrate, first, a varnish of a photosensitive insulating material is applied onto a metal support and dried to form a base film, which is then exposed and developed into a predetermined pattern. , If necessary, heat-cured to form a base insulating layer.
　そのようなベース絶縁層の材料として、例えば、ポリイミド前駆体と、現像促進剤としてのイミドアクリレート化合物と、ピリジン系感光剤とを含有するポリイミド前駆体組成物が提案されている（例えば、特許文献２参照。）。 As a material for such a base insulating layer, for example, a polyimide precursor composition containing a polyimide precursor, an imide acrylate compound as a development accelerator, and a pyridine-based photosensitive agent has been proposed (for example, Patent Documents). See 2.).
特開２０１８－１９０７８７号公報JP-A-2018-190787 特開２０１３－１００４４１号公報Japanese Unexamined Patent Publication No. 2013-100441
　しかるに、特許文献１に記載されるような撮像素子実装基板では、撮像素子の端子と撮像素子接続端子との接続強度向上の観点から、実装面と撮像素子との間にアンダーフィル層を設ける場合がある。 However, in the image sensor mounting substrate as described in Patent Document 1, when an underfill layer is provided between the mounting surface and the image sensor from the viewpoint of improving the connection strength between the terminal of the image sensor and the image sensor connection terminal. There is.
　しかし、特許文献２に記載されるポリイミド前駆体組成物からベース絶縁層が形成されている場合、湿熱条件下において、ベース絶縁層に対するアンダーフィル層の密着性が低下し、アンダーフィル層がベース絶縁層から剥離するおそれがある。 However, when the base insulating layer is formed from the polyimide precursor composition described in Patent Document 2, the adhesion of the underfill layer to the base insulating layer is lowered under moist heat conditions, and the underfill layer is used for base insulation. May peel off from the layer.
　また、撮像素子実装基板に実装された撮像素子は、交換や再利用のために取り外してリワークされる場合があり、この場合、アンダーフィル層をベース絶縁層から引き剥がすことが望まれる。このとき、ベース絶縁層とアンダーフィル層との密着性が過度に高いと、アンダーフィル層をベース絶縁層から引き剥がすことが困難となり、ひいては、撮像素子のリワーク性を確保できないという不具合がある。 Further, the image sensor mounted on the image sensor mounting substrate may be removed and reworked for replacement or reuse. In this case, it is desirable to peel off the underfill layer from the base insulating layer. At this time, if the adhesion between the base insulating layer and the underfill layer is excessively high, it becomes difficult to peel off the underfill layer from the base insulating layer, and there is a problem that the reworkability of the image sensor cannot be ensured.
　本発明は、湿熱条件下における第１絶縁層に対する第２絶縁層の密着性の低下を抑制できながら、電子部品のリワーク性を確保できる配線回路基板、および、製造効率のよい配線回路基板の製造方法を提供する。 The present invention manufactures a wiring circuit board capable of ensuring reworkability of electronic components while suppressing a decrease in adhesion of the second insulating layer to the first insulating layer under moist heat conditions, and a wiring circuit board having high manufacturing efficiency. Provide a method.
　本発明［１］は、ポリイミドと、現像促進剤と、感光剤とを含有する第１絶縁層と、前記第１絶縁層の厚み方向の一方面に配置される端子と、を備え、前記第１絶縁層における前記現像促進剤の含有割合と前記感光剤の含有割合との総和は、５ｐｐｍ以上５０ｐｐｍ以下である、配線回路基板を含む。 The present invention [1] includes a first insulating layer containing a polyimide, a development accelerator, and a photosensitizer, and terminals arranged on one surface of the first insulating layer in the thickness direction. The sum of the content ratio of the development accelerator and the content ratio of the photosensitizer in one insulating layer includes a wiring circuit board of 5 ppm or more and 50 ppm or less.
　このような構成によれば、第１絶縁層における現像促進剤の含有割合と感光剤の含有割合との総和が上記下限以上であるので、第１絶縁層の厚み方向の一方面に電子部品を実装し、第１絶縁層と電子部品との間に第２絶縁層を設けた状態で、配線回路基板を湿熱条件下に置いても、第１絶縁層に対する第２絶縁層の密着性が低下することを抑制できる。 According to such a configuration, the sum of the content ratio of the development accelerator and the content ratio of the photosensitizer in the first insulating layer is equal to or more than the above lower limit, so that the electronic component is placed on one surface in the thickness direction of the first insulating layer. Even if the wiring circuit board is placed under moist heat conditions with the second insulating layer provided between the first insulating layer and the electronic component after mounting, the adhesion of the second insulating layer to the first insulating layer is reduced. Can be suppressed.
　また、配線回路基板に実装した電子部品を、配線回路基板から取り外してリワークする場合、第１絶縁層における現像促進剤の含有割合と感光剤の含有割合との総和が上記上限以下であるので、第１絶縁層に対する第２絶縁層の密着性を、第２絶縁層が第１絶縁層から引き剥がし可能となるように調整でき、電子部品のリワーク性を確保することができる。 Further, when the electronic component mounted on the wiring circuit board is removed from the wiring circuit board and reworked, the total of the content ratio of the development accelerator and the content ratio of the photosensitizer in the first insulating layer is not more than the above upper limit. The adhesion of the second insulating layer to the first insulating layer can be adjusted so that the second insulating layer can be peeled off from the first insulating layer, and the reworkability of the electronic component can be ensured.
　本発明［２］は、前記現像促進剤は、イミドアクリレート化合物および／またはポリエチレングリコール化合物を含む、上記［１］に記載の配線回路基板を含む。 The present invention [2] includes the wiring circuit board according to the above [1], wherein the development accelerator contains an imide acrylate compound and / or a polyethylene glycol compound.
　このような構成によれば、現像促進剤がイミドアクリレート化合物および／またはポリエチレングリコール化合物を含むので、第１絶縁層における現像促進剤の含有割合と感光剤の含有割合との総和を上記範囲に調整できながら、ポリイミド前駆体と、現像促進剤と、感光剤とを含有するワニスの感光性を確保できる。 According to such a configuration, since the development accelerator contains an imide acrylate compound and / or a polyethylene glycol compound, the total of the content ratio of the development accelerator and the content ratio of the photosensitizer in the first insulating layer is adjusted to the above range. While being possible, the photosensitivity of the varnish containing the polyimide precursor, the development accelerator, and the photosensitizer can be ensured.
　本発明［３］は、金属支持層を準備する工程と、前記金属支持層上に、ポリイミドと、感光剤と、現像促進剤とを含有する第１絶縁層を形成する工程と、前記第１絶縁層の前記厚み方向の一方面に端子を形成する工程と、を含み、前記第１絶縁層を形成する工程は、前記金属支持層上に、ポリイミド前駆体と、感光剤と、現像促進剤とを含有するワニスを塗布する工程と、前記ワニスを露光および現像する工程と、現像後の前記ワニスを、３００℃以上４００℃以下に、１００分以上加熱する工程と、を含む、配線回路基板の製造方法を含む。 The present invention [3] includes a step of preparing a metal support layer, a step of forming a first insulating layer containing a polyimide, a photosensitizer, and a development accelerator on the metal support layer, and the first step. The step of forming the first insulating layer includes a step of forming a terminal on one surface of the insulating layer in the thickness direction, and the step of forming the first insulating layer includes a polyimide precursor, a photosensitizer, and a development accelerator on the metal support layer. A wiring circuit board including a step of applying a varnish containing the above, a step of exposing and developing the varnish, and a step of heating the developed varnish to 300 ° C. or higher and 400 ° C. or lower for 100 minutes or longer. Including the manufacturing method of.
　このような方法によれば、現像後のワニスを３００℃以上４００℃以下に１００分以上加熱するので、第１絶縁層における感光剤の含有割合と現像促進剤の含有割合との総和を、５ｐｐｍ以上５０ｐｐｍ以下に調整することができる。その結果、簡易な方法でありながら、上記した配線回路基板を効率よく製造することができる。 According to such a method, the developed varnish is heated to 300 ° C. or higher and 400 ° C. or lower for 100 minutes or longer. Therefore, the sum of the content ratio of the photosensitive agent and the content ratio of the development accelerator in the first insulating layer is 5 ppm. It can be adjusted to 50 ppm or less. As a result, the above-mentioned wiring circuit board can be efficiently manufactured even though it is a simple method.
　本発明の配線回路基板によれば、湿熱条件下における第１絶縁層に対する第２絶縁層の密着性の低下を抑制できながら、電子部品のリワーク性を確保できる。 According to the wiring circuit board of the present invention, it is possible to ensure reworkability of electronic components while suppressing a decrease in adhesion of the second insulating layer to the first insulating layer under moist heat conditions.
　本発明の配線回路基板の製造方法によれば、上記した配線回路基板を効率よく製造することができる。 According to the method for manufacturing a wiring circuit board of the present invention, the above-mentioned wiring circuit board can be efficiently manufactured.
図１は、本発明の配線回路基板の一実施形態である撮像素子実装基板の平面図を示す。FIG. 1 shows a plan view of an image pickup device mounting board according to an embodiment of the wiring circuit board of the present invention. 図２は、図１に示す撮像素子実装基板におけるＡ－Ａ断面図を示す。FIG. 2 shows a cross-sectional view taken along the line AA of the image sensor mounting substrate shown in FIG. 図３Ａ～図３Ｄは、図２に示す撮像素子実装基板の製造工程図を示し、図３Ａが、金属支持体準備工程およびベース絶縁層形成工程、図３Ｂが、導体パターン形成工程、図３Ｃが、カバー絶縁層形成工程、図３Ｄが、金属支持体除去工程を示す。3A to 3D show a manufacturing process diagram of the image pickup device mounting substrate shown in FIG. 2, FIG. 3A is a metal support preparation step and a base insulating layer forming step, FIG. 3B is a conductor pattern forming step, and FIG. 3C is. , Cover insulating layer forming step, FIG. 3D shows a metal support removing step. 図４Ｅおよび図４Ｆは、図３Ｄに続いて、撮像素子を撮像素子実装基板に実装する工程図を示し、図４Ｅが、素子接続工程、図４Ｆが、アンダーフィル形成工程を示す。4E and 4F show a process diagram of mounting the image pickup device on the image pickup device mounting substrate following FIG. 3D, FIG. 4E shows the element connection step, and FIG. 4F shows the underfill forming step. 図５は、図２に示す撮像素子実装基板を備える撮像装置を示す。FIG. 5 shows an image pickup apparatus including the image pickup device mounting substrate shown in FIG.
　１．撮像素子実装基板
　図１および図２を参照して、本発明の配線回路基板の一実施形態としての撮像素子実装基板１（以下、実装基板１とする。）を説明する。 1. 1. Image sensor mounting board With reference to FIGS. 1 and 2, the image sensor mounting board 1 (hereinafter referred to as mounting board 1) as an embodiment of the wiring circuit board of the present invention will be described.
　図１に示すように、実装基板１は、電子部品の一例としての撮像素子２１（後述、図４Ｆ参照）を実装するためのフレキシブル配線回路基板（ＦＰＣ）であって、撮像素子２１を未だ備えていない。実装基板１は、平面視略矩形（長方形状）の平板形状（シート形状）を有している。 As shown in FIG. 1, the mounting board 1 is a flexible wiring circuit board (FPC) for mounting an image pickup device 21 (see FIG. 4F described later) as an example of an electronic component, and is still provided with the image pickup device 21. Not done. The mounting substrate 1 has a flat plate shape (sheet shape) that is substantially rectangular (rectangular) in a plan view.
　実装基板１は、ハウジング配置部２、および、外部部品接続部３を備える。 The mounting board 1 includes a housing arrangement portion 2 and an external component connection portion 3.
　ハウジング配置部２は、ハウジング２２（後述、図５参照）や撮像素子２１が配置される部分である。具体的には、ハウジング配置部２は、ハウジング２２が実装基板１に配置された場合において、実装基板１の厚み方向に投影したときに、ハウジング２２と重複する部分である。ハウジング配置部２の略中央には、端子の一例としての第１端子１０（後述）が複数配置されている。 The housing arrangement portion 2 is a portion in which the housing 22 (described later, see FIG. 5) and the image sensor 21 are arranged. Specifically, the housing arrangement portion 2 is a portion that overlaps with the housing 22 when the housing 22 is arranged on the mounting substrate 1 and projected in the thickness direction of the mounting substrate 1. A plurality of first terminals 10 (described later) as an example of terminals are arranged substantially in the center of the housing arrangement portion 2.
　外部部品接続部３は、ハウジング配置部２以外の領域であって、外部部品と接続するための部分である。外部部品接続部３は、実装基板１の長手方向にハウジング配置部２と連続して配置されている。外部部品接続部３には、第２端子１１（後述）が複数配置されている。 The external component connecting portion 3 is an area other than the housing arranging portion 2 and is a portion for connecting to the external component. The external component connecting portion 3 is arranged continuously with the housing arranging portion 2 in the longitudinal direction of the mounting board 1. A plurality of second terminals 11 (described later) are arranged in the external component connecting portion 3.
　図２に示すように、実装基板１は、第１絶縁層の一例としてのベース絶縁層４と、導体パターン５と、カバー絶縁層６とを、ベース絶縁層４の厚み方向に順に備える。なお、以下では、ベース絶縁層４の厚み方向を単に厚み方向として記載する。図２において、紙面上側がベース絶縁層４の厚み方向の一方側であり、紙面下側がベース絶縁層４の厚み方向の他方側である。 As shown in FIG. 2, the mounting substrate 1 includes a base insulating layer 4 as an example of the first insulating layer, a conductor pattern 5, and a cover insulating layer 6 in order in the thickness direction of the base insulating layer 4. In the following, the thickness direction of the base insulating layer 4 is simply described as the thickness direction. In FIG. 2, the upper side of the paper surface is one side in the thickness direction of the base insulating layer 4, and the lower side of the paper surface is the other side in the thickness direction of the base insulating layer 4.
　図１に示すように、ベース絶縁層４は、実装基板１の外形をなし、平面視略矩形状を有する。ベース絶縁層４は、後述する金属支持体１９（図３Ａ～図３Ｃ参照）に支持されておらず、実装基板１は、金属支持体１９（金属支持層）を備えない。 As shown in FIG. 1, the base insulating layer 4 has the outer shape of the mounting substrate 1 and has a substantially rectangular shape in a plan view. The base insulating layer 4 is not supported by the metal support 19 (see FIGS. 3A to 3C) described later, and the mounting substrate 1 does not include the metal support 19 (metal support layer).
　ベース絶縁層４は、複数の第１開口部７と、複数の第２開口部８とを備える。 The base insulating layer 4 includes a plurality of first openings 7 and a plurality of second openings 8.
　複数の第１開口部７は、第１端子１０（後述）を厚み方向一方側から露出する。複数の第１開口部７は、ハウジング配置部２の中央部に、矩形枠状となるように、互いに間隔を隔てて整列配置されている。第１開口部７は、ベース絶縁層４を厚み方向に貫通し、平面視略円形状を有している。第１開口部７は、厚み方向一方側に向かうに従って開口断面積が小さくなるテーパ形状を有する（図２参照）。 The plurality of first openings 7 expose the first terminal 10 (described later) from one side in the thickness direction. The plurality of first openings 7 are arranged in a central portion of the housing arrangement portion 2 so as to form a rectangular frame at intervals of each other. The first opening 7 penetrates the base insulating layer 4 in the thickness direction and has a substantially circular shape in a plan view. The first opening 7 has a tapered shape in which the cross-sectional area of the opening decreases toward one side in the thickness direction (see FIG. 2).
　複数の第２開口部８は、第２端子１１（後述）を厚み方向一方側から露出する。複数の第２開口部８は、外部部品接続部３において、実装基板１の幅方向に互いに間隔を隔てて整列配置されている。第２開口部８は、ベース絶縁層４を厚み方向に貫通し、平面視略矩形状（長方形状）を有している。 The plurality of second openings 8 expose the second terminal 11 (described later) from one side in the thickness direction. The plurality of second openings 8 are arranged in the external component connecting portion 3 so as to be spaced apart from each other in the width direction of the mounting substrate 1. The second opening 8 penetrates the base insulating layer 4 in the thickness direction and has a substantially rectangular shape (rectangular shape) in a plan view.
　また、図２に示すように、ベース絶縁層４は、厚み方向において、一方面４Ａと、他方面４Ｂとを備える。 Further, as shown in FIG. 2, the base insulating layer 4 includes one surface 4A and the other surface 4B in the thickness direction.
　ベース絶縁層の一方面４Ａは、厚み方向の一方側に位置する。ベース絶縁層の一方面４Ａは、平坦（平滑）状を有し、その全体が露出されている。ベース絶縁層の他方面４Ｂは、厚み方向の他方側に位置し、厚み方向において一方面４Ａの反対側に位置する。ベース絶縁層の他方面４Ｂは、カバー絶縁層６により被覆されている。 One side 4A of the base insulating layer is located on one side in the thickness direction. One surface 4A of the base insulating layer has a flat (smooth) shape, and the entire surface thereof is exposed. The other surface 4B of the base insulating layer is located on the other side in the thickness direction and is located on the opposite side of the one surface 4A in the thickness direction. The other surface 4B of the base insulating layer is covered with the cover insulating layer 6.
　このようなベース絶縁層４は、ポリイミドと、現像促進剤と、感光剤と、を含有する。 Such a base insulating layer 4 contains a polyimide, a development accelerator, and a photosensitizer.
　ポリイミドは、例えば、特開２０１８－１９０７８７号公報に記載されるポリイミドであって、酸二無水物成分とジアミン成分との反応生成物（硬化物）を含む。より詳しくは、ポリイミドは、酸二無水物成分とジアミン成分との反応生成物であるポリアミド酸を、イミド化させることにより調製される。 The polyimide is, for example, the polyimide described in JP-A-2018-190787 and contains a reaction product (cured product) of an acid dianhydride component and a diamine component. More specifically, polyimide is prepared by imidizing polyamic acid, which is a reaction product of an acid dianhydride component and a diamine component.
　酸二無水物成分として、例えば、特開２０１８－１９０７８７号公報に記載される芳香族酸二無水物（例えば、３，３’，４，４’－ビフェニルテトラカルボン酸二無水物（ＢＰＤＡ）などのビフェニルテトラカルボン酸二無水物など）、および、脂肪族酸二無水物などが挙げられる。酸二無水物成分は、単独使用または２種以上併用することができる。 Examples of the acid dianhydride component include aromatic dianhydrides (for example, 3,3', 4,4'-biphenyltetracarboxylic dianhydride (BPDA)) described in JP-A-2018-190787. (Biphenyltetracarboxylic dianhydride, etc.), and aliphatic acid dianhydride, etc. The acid dianhydride component can be used alone or in combination of two or more.
　酸二無水物成分は、好ましくは、芳香族酸二無水物を含み、さらに好ましくは、３，３’，４，４’－ビフェニルテトラカルボン酸二無水物（ＢＰＤＡ）を含む。また、酸二無水物成分は、好ましくは、芳香族酸二無水物（３，３’，４，４’－ビフェニルテトラカルボン酸二無水物）からなる。 The acid dianhydride component preferably contains an aromatic acid dianhydride, and more preferably contains 3,3', 4,4'-biphenyltetracarboxylic dianhydride (BPDA). The acid dianhydride component is preferably composed of aromatic acid dianhydride (3,3', 4,4'-biphenyltetracarboxylic dianhydride).
　ジアミン成分として、例えば、特開２０１８－１９０７８７号公報に記載される芳香族ジアミンおよび脂肪族ジアミンなどが挙げられる。酸二無水物成分は、単独使用または２種以上併用することができる。 Examples of the diamine component include aromatic diamines and aliphatic diamines described in JP-A-2018-190787. The acid dianhydride component can be used alone or in combination of two or more.
　ジアミン成分は、好ましくは、芳香族ジアミンを含み、さらに好ましくは、芳香族ジアミンからなる。 The diamine component preferably contains an aromatic diamine, and more preferably consists of an aromatic diamine.
　芳香族ジアミンとして、例えば、ｐ－フェニレンジアミン（ＰＰＤ）などのフェニレンジアミンなどが挙げられる。 Examples of the aromatic diamine include phenylenediamine such as p-phenylenediamine (PPD).
　また、芳香族ジアミンには、２つ以上の芳香族環が単結合により結合し、２つ以上のアミノ基のそれぞれが別々の芳香族環上に直接または置換基の一部として結合している芳香族ジアミンも含まれる。そのような芳香族ジアミンは、例えば、下記一般式（１）で示される。 In addition, two or more aromatic rings are bonded to the aromatic diamine by a single bond, and each of the two or more amino groups is bonded to a separate aromatic ring directly or as a part of a substituent. Aromatic diamine is also included. Such an aromatic diamine is represented by, for example, the following general formula (1).
Figure JPOXMLDOC01-appb-C000001
Figure JPOXMLDOC01-appb-C000001
（一般式（１）中、ａは０または１以上の自然数、Ｒ１は、水素原子または置換基を示す。アミノ基は、ベンゼン環同士の結合に対して、メタ位またはパラ位に結合する。）
　上記一般式（１）においてＲ１で示される置換基として、例えば、メチル基などの炭素数３以下のアルキル基、例えば、トリフルオロメチル基、パーフルオロエチル基、パーフルオロプロピル基などの炭素数３以下のハロアルキル基（好ましくは、フルオロアルキル基）、例えば、クロロ、フルオロなどのハロゲン原子などが挙げられる。 (In the general formula (1), a is a natural number of 0 or 1 or more, R 1 is a hydrogen atom or a substituent. The amino group is bonded to the meta position or the para position with respect to the bond between the benzene rings. .)
As substituents represented by R 1 in the general formula (1), for example, an alkyl group having 3 or less carbon atoms such as a methyl group, for example, a trifluoromethyl group, perfluoroethyl group, carbon atoms, such as perfluoro propyl Examples thereof include a haloalkyl group of 3 or less (preferably a fluoroalkyl group), for example, a halogen atom such as chloro or fluoro.
　上記一般式（１）において、Ｒ１は、好ましくは、置換基を示し、さらに好ましくは、ハロアルキル基、とりわけ好ましくは、フルオロアルキル基、特に好ましくは、トリフルオロメチル基が挙げられる。 In the above general formula (1), R 1 preferably represents a substituent, more preferably a haloalkyl group, particularly preferably a fluoroalkyl group, and particularly preferably a trifluoromethyl group.
　上記一般式（１）で示される芳香族ジアミンとして、具体例には、２，２’－ジトリフルオロメチル－４，４’－ジアミノビフェニル（別称：２，２’－ビス（トリフルオロメチル）－４，４’－ジアミノビフェニル、ＴＦＭＢ）などが挙げられる。 Specific examples of the aromatic diamine represented by the above general formula (1) include 2,2'-ditrifluoromethyl-4,4'-diaminobiphenyl (also known as 2,2'-bis (trifluoromethyl)-. 4,4'-diaminobiphenyl, TFMB) and the like.
　このような芳香族ジアミンは、好ましくは、フェニレンジアミンと、上記一般式（１）に示される芳香族ジアミンとの組み合わせを含み、さらに好ましくは、フェニレンジアミンと、上記一般式（１）においてＲ１がフルオロアルキル基（トリフルオロメチル基）である芳香族ジアミンとの組み合わせを含む。 Such an aromatic diamine preferably contains a combination of phenylenediamine and the aromatic diamine represented by the general formula (1), and more preferably phenylenediamine and R 1 in the general formula (1). Includes a combination with an aromatic diamine where is a fluoroalkyl group (trifluoromethyl group).
　このようなジアミン成分において、上記一般式（１）に示される芳香族ジアミンの含有割合は、例えば、１５ｍｏｌ％以上、好ましくは、２０ｍｏｌ％以上、例えば、８０ｍｏｌ％以下、好ましくは、５０ｍｏｌ％以下である。 In such a diamine component, the content ratio of the aromatic diamine represented by the general formula (1) is, for example, 15 mol% or more, preferably 20 mol% or more, for example, 80 mol% or less, preferably 50 mol% or less. is there.
　また、酸二無水物成分が３，３’，４，４’－ビフェニルテトラカルボン酸二無水物（ＢＰＤＡ）を含有し、ジアミン成分が、フェニレンジアミン（ＰＰＤ）および２，２’－ジトリフルオロメチル－４，４’－ジアミノビフェニル（ＴＦＭＢ）を含有する場合、ポリイミドは、下記一般式（２）に示される構造単位Ａと、下記一般式（３）に示される構造単位Ｂとを含有する。 Further, the acid dianhydride component contains 3,3', 4,4'-biphenyltetracarboxylic dianhydride (BPDA), and the diamine component is phenylenediamine (PPD) and 2,2'-ditrifluoromethyl. When -4,4'-diaminobiphenyl (TFMB) is contained, the polyimide contains a structural unit A represented by the following general formula (2) and a structural unit B represented by the following general formula (3).
Figure JPOXMLDOC01-appb-C000002
Figure JPOXMLDOC01-appb-C000002
Figure JPOXMLDOC01-appb-C000003
Figure JPOXMLDOC01-appb-C000003
　このようなポリイミドにおいて、上記一般式（１）に示される構造単位Ａと、上記一般式（２）に示される構造単位Ｂとのｍｏｌ比（構造単位Ａ／構造単位Ｂ）は、例えば、１５／８５～８０／２０、好ましくは、２０／８０～５０／５０である。 In such a polyimide, the mol ratio (structural unit A / structural unit B) of the structural unit A represented by the general formula (1) and the structural unit B represented by the general formula (2) is, for example, 15. / 85 to 80/20, preferably 20/80 to 50/50.
　現像促進剤は、例えば、イミドアクリレート化合物および／またはポリエチレングリコール化合物を含む。 The development accelerator contains, for example, an imide acrylate compound and / or a polyethylene glycol compound.
　イミドアクリレート化合物は、例えば、特開２０１３－１００４４１号公報に記載されるイミドアクリレート化合物を含む。 The imide acrylate compound includes, for example, the imide acrylate compound described in JP2013-100441A.
　具体的には、イミドアクリレート化合物は、下記一般式（４）にて示される。 Specifically, the imide acrylate compound is represented by the following general formula (4).
Figure JPOXMLDOC01-appb-C000004
Figure JPOXMLDOC01-appb-C000004
（一般式（４）中、Ｒ２は、水素原子またはメチル基を示す。Ｒ３は、炭素数２以上の２価の炭化水素基を示す。）
　上記一般式（４）において、Ｒ２は、好ましくは、水素原子を示す。 (In the general formula (4), R 2 represents a hydrogen atom or a methyl group. R 3 represents a divalent hydrocarbon group having 2 or more carbon atoms.)
In the above general formula (4), R 2 preferably represents a hydrogen atom.
　上記一般式（４）において、Ｒ３は、好ましくは、炭素数２以上のアルキレン基を示し、さらに好ましくは、エチレン基を示す。 In the above general formula (4), R 3 preferably represents an alkylene group having 2 or more carbon atoms, and more preferably an ethylene group.
　このような上記一般式（４）に示されるイミドアクリレート化合物として、具体的には、ｎ－アクリロイルオキシエチルヘキサヒドロフタルイミドなどが挙げられる。 Specific examples of the imide acrylate compound represented by the general formula (4) include n-acryloyloxyethyl hexahydrophthalimide and the like.
　ポリエチレングリコール化合物は、例えば、特開２０１３－１００４４１号公報に記載されるポリエチレングリコール化合物を含む。 The polyethylene glycol compound includes, for example, the polyethylene glycol compound described in Japanese Patent Application Laid-Open No. 2013-100441.
　具体的には、ポリエチレングリコール化合物は、下記一般式（５）にて示される。 Specifically, the polyethylene glycol compound is represented by the following general formula (5).
Figure JPOXMLDOC01-appb-C000005
Figure JPOXMLDOC01-appb-C000005
（一般式（５）中、Ｒ４は、ヒドロキシル基またはメトキシ基を示す。Ｒ５は、水素原子またはメチル基を示す。ｂは、４～２３の自然数を示す。）
　上記一般式（５）において、Ｒ４とＲ５との組み合わせとして、ヒドロキシル基（Ｒ４）および水素原子（Ｒ５）、ヒドロキシル基（Ｒ４）およびメチル基（Ｒ５）、メトキシ基（Ｒ４）およびメチル基（Ｒ５）が挙げられ、好ましくは、ヒドロキシル基（Ｒ４）および水素原子（Ｒ５）が挙げられる。 (In general formula (5), R 4 represents a hydroxyl group or a methoxy group. R 5 represents a hydrogen atom or a methyl group. B represents a natural number of 4 to 23.)
In the above general formula (5), as a combination of R 4 and R 5 , a hydroxyl group (R 4 ) and a hydrogen atom (R 5 ), a hydroxyl group (R 4 ) and a methyl group (R 5 ), and a methoxy group (R) 4 ) and a methyl group (R 5 ), preferably a hydroxyl group (R 4 ) and a hydrogen atom (R 5 ).
　このような上記一般式（５）に示されるポリエチレングリコール化合物の数平均分子量（Ｍｎ）は、例えば、２００以上、例えば、１０００以下、好ましくは、４００以下である。なお、数平均分子量は、ゲル浸透クロマトグラフィー（ＧＰＣ）法にて測定でき、ポリエチレンオキサイド換算にて算出できる。 The number average molecular weight (Mn) of the polyethylene glycol compound represented by the general formula (5) is, for example, 200 or more, for example, 1000 or less, preferably 400 or less. The number average molecular weight can be measured by gel permeation chromatography (GPC) method and can be calculated in terms of polyethylene oxide.
　このような現像促進剤は、好ましくは、上記一般式（４）に示されるイミドアクリレート化合物からなる。 Such a development accelerator preferably comprises an imide acrylate compound represented by the above general formula (4).
　感光剤は、例えば、特開２０１３－１００４４１号公報に記載されるピリジン系感光剤を含む。 The photosensitizer includes, for example, a pyridine-based photosensitizer described in Japanese Patent Application Laid-Open No. 2013-100441.
　具体的には、ピリジン系感光剤は、下記一般式（６）にて示される。 Specifically, the pyridine-based photosensitizer is represented by the following general formula (6).
Figure JPOXMLDOC01-appb-C000006
Figure JPOXMLDOC01-appb-C000006
（一般式（６）中、Ｒ６～Ｒ１０は、水素原子または炭素数１～４のアルキル基を示す。Ｒ６～Ｒ１０は、互いに同じであってもよく異なってもよい。）
　上記一般式（６）において、Ｒ６およびＲ７のそれぞれは、好ましくは、水素原子またはメチル基を示し、さらに好ましくは、水素原子を示す。 (In the general formula (6), R 6 to R 10 represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. R 6 to R 10 may be the same or different from each other.)
In the above general formula (6), each of R 6 and R 7 preferably represents a hydrogen atom or a methyl group, and more preferably a hydrogen atom.
　上記一般式（６）において、Ｒ８は、好ましくは、炭素数１～４のアルキル基を示し、さらに好ましくは、メチル基またはエチル基を示し、とりわけ好ましくは、エチル基を示す。 In the above general formula (6), R 8 preferably represents an alkyl group having 1 to 4 carbon atoms, more preferably a methyl group or an ethyl group, and particularly preferably an ethyl group.
　上記一般式（６）において、Ｒ９およびＲ１０のそれぞれは、好ましくは、炭素数１～４のアルキル基を示し、さらに好ましくは、メチル基またはエチル基を示し、とりわけ好ましくは、メチル基を示す。 In the above general formula (6), each of R 9 and R 10 preferably represents an alkyl group having 1 to 4 carbon atoms, more preferably a methyl group or an ethyl group, and particularly preferably a methyl group. Shown.
　このような上記一般式（６）に示されるピリジン系感光剤として、具体的には、１－エチル－３，５－ジメトキシカルボニル－４－（２－ニトロフェニル）－１，４－ジヒドロピリジンなどが挙げられる。 Specific examples of the pyridine-based photosensitizer represented by the general formula (6) include 1-ethyl-3,5-dimethoxycarbonyl-4- (2-nitrophenyl) -1,4-dihydropyridine. Can be mentioned.
　また、ベース絶縁層４における感光剤の含有割合と現像促進剤の含有割合との総和（質量割合）は、５ｐｐｍ以上５０ｐｐｍ以下である。なお、感光剤の含有割合と現像促進剤の含有割合との総和は、ＴＯＦ－ＳＩＭＳにより測定できる（以下同様）。 The total (mass ratio) of the content ratio of the photosensitizer and the content ratio of the development accelerator in the base insulating layer 4 is 5 ppm or more and 50 ppm or less. The total of the content ratio of the photosensitizer and the content ratio of the development accelerator can be measured by TOF-SIMS (the same applies hereinafter).
　感光剤の含有割合と現像促進剤の含有割合との総和が上記下限以上であれば、ベース絶縁層４に対するアンダーフィル層１８（後述）の密着性を、アンダーフィル層１８（後述）がベース絶縁層４から引き剥がし可能となるように調整でき、撮像素子２１のリワーク性を確保することができる。また、感光剤の含有割合と現像促進剤の含有割合との総和が上記上限以下であれば、湿熱条件下におけるベース絶縁層４に対するアンダーフィル層１８（後述）の密着性の低下を抑制できる。 When the sum of the content ratio of the photosensitizer and the content ratio of the development accelerator is equal to or higher than the above lower limit, the adhesion of the underfill layer 18 (described later) to the base insulating layer 4 is determined by the underfill layer 18 (described later). It can be adjusted so that it can be peeled off from the layer 4, and the reworkability of the image pickup device 21 can be ensured. Further, when the sum of the content ratio of the photosensitizer and the content ratio of the development accelerator is not more than the above upper limit, it is possible to suppress a decrease in the adhesion of the underfill layer 18 (described later) to the base insulating layer 4 under moist heat conditions.
　また、ベース絶縁層４は、さらに、公知の添加剤を含有できる。公知の添加剤として、例えば、増感剤、重合停止剤、連鎖移動剤、レベリング剤、可塑剤、界面活性剤、消泡剤などが挙げられる。ベース絶縁層４における公知の添加剤の含有割合は、例えば、１５質量％以下、好ましくは、１０質量％以下である。 Further, the base insulating layer 4 can further contain a known additive. Known additives include, for example, sensitizers, polymerization inhibitors, chain transfer agents, leveling agents, plasticizers, surfactants, defoamers and the like. The content ratio of the known additive in the base insulating layer 4 is, for example, 15% by mass or less, preferably 10% by mass or less.
　ベース絶縁層４の厚みは、例えば、１μｍ以上、好ましくは、３μｍ以上、例えば、３０μｍ以下、好ましくは、１２μｍ以下、さらに好ましくは、８μｍ以下である。 The thickness of the base insulating layer 4 is, for example, 1 μm or more, preferably 3 μm or more, for example, 30 μm or less, preferably 12 μm or less, and more preferably 8 μm or less.
　導体パターン５は、複数の第１端子１０と、複数の第２端子１１（図１参照）と、複数の配線９とを備える。 The conductor pattern 5 includes a plurality of first terminals 10, a plurality of second terminals 11 (see FIG. 1), and a plurality of wirings 9.
　複数の第１端子１０は、ハウジング配置部２の中央部において、矩形枠状となるように、互いに間隔を隔てて整列配置されている（図１参照）。複数の第１端子１０は、実装される撮像素子２１の複数の端子２５（図４Ｅ参照）に対応するように設けられている。また、複数の第１端子１０は、複数の第１開口部７に対応して設けられる。第１端子１０は、平面視略円形状を有する。第１端子１０は、第１開口部７に充填され、厚み方向一方側から見て、ベース絶縁層４から露出されている。厚み方向における第１端子１０の一方面１０Ａは、平坦（平滑）状を有する。厚み方向における第１端子１０の一方面１０Ａは、ベース絶縁層４の一方面４Ａと略面一である。これによって、第１端子１０は、ベース絶縁層４の一方面４Ａに配置される。 The plurality of first terminals 10 are arranged and arranged at the center of the housing arrangement portion 2 so as to form a rectangular frame at intervals from each other (see FIG. 1). The plurality of first terminals 10 are provided so as to correspond to the plurality of terminals 25 (see FIG. 4E) of the mounted image sensor 21. Further, the plurality of first terminals 10 are provided corresponding to the plurality of first openings 7. The first terminal 10 has a substantially circular shape in a plan view. The first terminal 10 is filled in the first opening 7 and is exposed from the base insulating layer 4 when viewed from one side in the thickness direction. One surface 10A of the first terminal 10 in the thickness direction has a flat (smooth) shape. One surface 10A of the first terminal 10 in the thickness direction is substantially flush with one surface 4A of the base insulating layer 4. As a result, the first terminal 10 is arranged on one surface 4A of the base insulating layer 4.
　図１に示すように、複数の第２端子１１は、外部部品接続部３において、互いに間隔を隔てて整列配置されている。複数の第２端子１１は、外部部品の複数の端子（図示せず）に対応するように設けられている。また、複数の第２端子１１は、複数の第２開口部８に対応して設けられる。第２端子１１は、平面視略矩形状（長方形状）を有している。第２端子１１は、第２開口部８に充填され、厚み方向一方側から見て、ベース絶縁層４から露出されている。厚み方向における第２端子１１の一方面は、ベース絶縁層４の一方面４Ａと略面一である。これによって、第２端子１１は、ベース絶縁層４の一方面４Ａに配置される。 As shown in FIG. 1, the plurality of second terminals 11 are aligned and arranged at the external component connecting portion 3 at intervals from each other. The plurality of second terminals 11 are provided so as to correspond to a plurality of terminals (not shown) of the external component. Further, the plurality of second terminals 11 are provided corresponding to the plurality of second openings 8. The second terminal 11 has a substantially rectangular shape (rectangular shape) in a plan view. The second terminal 11 is filled in the second opening 8 and is exposed from the base insulating layer 4 when viewed from one side in the thickness direction. One surface of the second terminal 11 in the thickness direction is substantially flush with one surface 4A of the base insulating layer 4. As a result, the second terminal 11 is arranged on one surface 4A of the base insulating layer 4.
　図２に示すように、複数の配線９は、ベース絶縁層４に対して厚み方向の他方側に配置され、具体的には、ベース絶縁層４の他方面４Ｂに配置される。 As shown in FIG. 2, the plurality of wirings 9 are arranged on the other side in the thickness direction with respect to the base insulating layer 4, and specifically, are arranged on the other surface 4B of the base insulating layer 4.
　複数の配線９は、複数の第１端子１０と複数の第２端子１１とを電気的に接続する。具体的には、各配線９の一端は、他方面４Ｂから第１開口部７に落ち込み、各第１端子１０と連続する。各配線９の他端は、他方面４Ｂから第２開口部８に落ち込み、各第２端子１１と連続する。 The plurality of wirings 9 electrically connect the plurality of first terminals 10 and the plurality of second terminals 11. Specifically, one end of each wiring 9 falls from the other surface 4B into the first opening 7 and is continuous with each first terminal 10. The other end of each wiring 9 falls from the other surface 4B into the second opening 8 and is continuous with each second terminal 11.
　導体パターン５の材料として、例えば、銅、銀、金、ニッケルまたはそれらを含む合金、半田などの金属材料が挙げられ、好ましくは、銅が挙げられる。 Examples of the material of the conductor pattern 5 include metal materials such as copper, silver, gold, nickel or alloys containing them, and solder, and copper is preferable.
　導体パターン５の厚みは、例えば、１μｍ以上、好ましくは、２μｍ以上、例えば、１５μｍ以下、好ましくは、１０μｍ以下である。 The thickness of the conductor pattern 5 is, for example, 1 μm or more, preferably 2 μm or more, for example, 15 μm or less, preferably 10 μm or less.
　カバー絶縁層６は、導体パターン５を被覆するように、ベース絶縁層４に対して厚み方向の他方側に配置され、具体的には、ベース絶縁層４の他方面４Ｂに配置される。カバー絶縁層６の外形は、ベース絶縁層４の外形と同一となるように形成される。 The cover insulating layer 6 is arranged on the other side in the thickness direction with respect to the base insulating layer 4 so as to cover the conductor pattern 5, and specifically, is arranged on the other surface 4B of the base insulating layer 4. The outer shape of the cover insulating layer 6 is formed to be the same as the outer shape of the base insulating layer 4.
　カバー絶縁層６の材料として、例えば、絶縁材料が挙げられる。絶縁材料として、例えば、ポリイミド、ポリアミドイミド、アクリル、ポリエーテルニトリル、ポリエーテルスルホン、ポリエチレンテレフタレート、ポリエチレンナフタレート、ポリ塩化ビニルなどの合成樹脂などが挙げられる。絶縁材料として、好ましくは、ベース絶縁層４と同様のポリイミドが挙げられる。 Examples of the material of the cover insulating layer 6 include an insulating material. Examples of the insulating material include synthetic resins such as polyimide, polyamideimide, acrylic, polyethernitrile, polyether sulfone, polyethylene terephthalate, polyethylene naphthalate, and polyvinyl chloride. As the insulating material, preferably, the same polyimide as the base insulating layer 4 can be mentioned.
　カバー絶縁層６の厚みは、例えば、１μｍ以上、好ましくは、２μｍ以上、例えば、３０μｍ以下、好ましくは、１０μｍ以下、さらに好ましくは、５μｍ以下である。 The thickness of the cover insulating layer 6 is, for example, 1 μm or more, preferably 2 μm or more, for example, 30 μm or less, preferably 10 μm or less, and more preferably 5 μm or less.
　このような実装基板１の厚み（ベース絶縁層４、導体パターン５およびカバー絶縁層６の厚みの総和）は、例えば、３μｍ以上、例えば、５０μｍ以下、好ましくは、３０μｍ以下である。 The thickness of such a mounting substrate 1 (the sum of the thicknesses of the base insulating layer 4, the conductor pattern 5, and the cover insulating layer 6) is, for example, 3 μm or more, for example, 50 μm or less, preferably 30 μm or less.
　２．撮像素子実装基板の製造方法
　次に、図３Ａ～図３Ｄを参照して、実装基板１の製造方法について説明する。実装基板１の製造方法は、例えば、金属支持体準備工程と、ベース絶縁層形成工程と、導体パターン形成工程と、カバー絶縁層形成工程とを順に含む。 2. 2. Manufacturing Method of Image Sensor Mounting Board Next, a manufacturing method of the mounting board 1 will be described with reference to FIGS. 3A to 3D. The method for manufacturing the mounting substrate 1 includes, for example, a metal support preparation step, a base insulating layer forming step, a conductor pattern forming step, and a cover insulating layer forming step in this order.
　図３Ａに示すように、金属支持体準備工程では、金属支持層の一例としての金属支持体１９を準備する。 As shown in FIG. 3A, in the metal support preparation step, the metal support 19 as an example of the metal support layer is prepared.
　金属支持体１９は、平面視略矩形（長方形状）の平板形状を有する。金属支持体１９の上面は、平坦（平滑）状を有する。 The metal support 19 has a flat plate shape that is substantially rectangular (rectangular) in a plan view. The upper surface of the metal support 19 has a flat (smooth) shape.
　金属支持体１９の材料は、例えば、ステンレス、４２アロイ、アルミニウムなどの金属材料が挙げられ、好ましくは、ステンレスが挙げられる。 Examples of the material of the metal support 19 include metal materials such as stainless steel, 42 alloy, and aluminum, and preferably stainless steel.
　金属支持体１９の厚みは、例えば、５μｍ以上、好ましくは、１０μｍ以上であり、例えば、５０μｍ以下、好ましくは、３０μｍ以下である。 The thickness of the metal support 19 is, for example, 5 μm or more, preferably 10 μm or more, and for example, 50 μm or less, preferably 30 μm or less.
　続いて、ベース絶縁層形成工程では、上記したポリイミドと、上記した現像促進剤と、上記した感光剤とを含有するベース絶縁層４を、金属支持体１９の上面に形成する。なお、図３Ａ～図３Ｄに示すベース絶縁層４の厚み方向は、図２に示すベース絶縁層４の厚み方向と逆であり、紙面上側が厚み方向の他方側、紙面下側が厚み方向の一方側である。つまり、ベース絶縁層４の一方面４Ａが、金属支持体１９と接触し、ベース絶縁層４の他方面４Ｂが、一方面４Ａに対して金属支持体１９の反対側に位置する。 Subsequently, in the base insulating layer forming step, the base insulating layer 4 containing the above-mentioned polyimide, the above-mentioned development accelerator, and the above-mentioned photosensitizer is formed on the upper surface of the metal support 19. The thickness direction of the base insulating layer 4 shown in FIGS. 3A to 3D is opposite to the thickness direction of the base insulating layer 4 shown in FIG. 2, with the upper side of the paper surface being the other side in the thickness direction and the lower side of the paper surface being one side in the thickness direction. On the side. That is, one surface 4A of the base insulating layer 4 comes into contact with the metal support 19, and the other surface 4B of the base insulating layer 4 is located on the opposite side of the metal support 19 with respect to the one surface 4A.
　具体的には、ベース絶縁層形成工程は、ベース絶縁層４の材料としてのワニスを金属支持体１９上に塗布する工程と、塗布したワニスを露光および現像する工程と、現像後のワニスを加熱する工程と、を含む。 Specifically, the base insulating layer forming step includes a step of applying a varnish as a material of the base insulating layer 4 on the metal support 19, a step of exposing and developing the applied varnish, and a step of heating the developed varnish. Including the process of
　ワニスは、ポリイミド前駆体の一例としてのポリアミド酸と、上記した現像促進剤と、上記した感光剤とを含有する。 The varnish contains a polyamic acid as an example of a polyimide precursor, the above-mentioned development accelerator, and the above-mentioned photosensitizer.
　ポリアミド酸は、上記した酸二無水物成分および上記したジアミン成分の反応生成物である。例えば、上記した酸二無水物成分および上記したジアミン成分を、有機溶媒の存在下において、例えば、１５℃以上４０℃以下、０．２時間以上７２時間以下の条件にて、反応させる。これによって、ポリアミド酸が調製される。 Polyamic acid is a reaction product of the above-mentioned acid dianhydride component and the above-mentioned diamine component. For example, the above-mentioned acid dianhydride component and the above-mentioned diamine component are reacted in the presence of an organic solvent, for example, under the conditions of 15 ° C. or higher and 40 ° C. or lower, 0.2 hours or longer and 72 hours or lower. This prepares the polyamic acid.
　有機溶媒は、上記した酸二無水物成分および上記したジアミン成分を溶解可能である。有機溶媒として、例えば、Ｎ－メチルピロリドンなどの極性非プロトン類、ジメチルホルムアミド、ジメチルスルホキシド、アセトニトリルなどが挙げられる。有機溶媒は、単独使用または２種以上併用することができる。 The organic solvent can dissolve the above-mentioned acid dianhydride component and the above-mentioned diamine component. Examples of the organic solvent include polar aprotons such as N-methylpyrrolidone, dimethylformamide, dimethyl sulfoxide, acetonitrile and the like. The organic solvent can be used alone or in combination of two or more.
　有機溶媒のなかでは、好ましくは、極性非プロトン類が挙げられ、さらに好ましくは、Ｎ－メチルピロリドンが挙げられる。なお、有機溶媒の含有割合は、適宜変更することができる。 Among the organic solvents, polar aprotons are preferable, and N-methylpyrrolidone is more preferable. The content ratio of the organic solvent can be changed as appropriate.
　また、ワニスにおける現像促進剤の含有割合は、ポリアミド酸１００質量部に対して、例えば、３０質量部以上１００質量部以下である。 Further, the content ratio of the development accelerator in the varnish is, for example, 30 parts by mass or more and 100 parts by mass or less with respect to 100 parts by mass of polyamic acid.
　また、ワニスにおける感光剤の含有割合は、ポリアミド酸１００質量部に対して、例えば、１０質量部以上５５質量部以下である。 Further, the content ratio of the photosensitizer in the varnish is, for example, 10 parts by mass or more and 55 parts by mass or less with respect to 100 parts by mass of polyamic acid.
　そして、ワニスを金属支持体１９の上面全体に塗布して乾燥させる。これによって、有機溶媒が揮発して、ベース皮膜が形成される。 Then, the varnish is applied to the entire upper surface of the metal support 19 and dried. As a result, the organic solvent volatilizes and a base film is formed.
　その後、ベース皮膜を、開口部（第１開口部７および第２開口部８）に対応するパターンを有するフォトマスクを介して露光する。その後、ベース皮膜を現像する。 After that, the base film is exposed through a photomask having a pattern corresponding to the openings (first opening 7 and second opening 8). Then, the base film is developed.
　次いで、現像後のベース皮膜を加熱して硬化させる。 Next, the developed base film is heated and cured.
　加熱温度は、３００℃以上、好ましくは、３３０℃以上、４００℃以下、好ましくは、３８０℃以下である。 The heating temperature is 300 ° C. or higher, preferably 330 ° C. or higher, 400 ° C. or lower, preferably 380 ° C. or lower.
　加熱時間は、１００分以上、好ましくは、１１０分以上、さらに好ましくは、１２０分以上、例えば、５００分以下、好ましくは、４００分以下、さらに好ましくは、３５０分以下である。 The heating time is 100 minutes or more, preferably 110 minutes or more, more preferably 120 minutes or more, for example, 500 minutes or less, preferably 400 minutes or less, still more preferably 350 minutes or less.
　加熱温度が上記下限以上、かつ、加熱時間が上記下限以上であると、ポリアミド酸がイミド化してポリイミドを形成するとともに、上記した現像促進剤および感光剤の大部分が除去される。そのため、ベース絶縁層４における現像促進剤の含有割合と感光剤の含有割合との総和を上記上限以下に調整できる。また、加熱温度が上記上限以下であると、ベース絶縁層４における現像促進剤の含有割合と感光剤の含有割合との総和を上記下限以上に確保できる。 When the heating temperature is equal to or higher than the above lower limit and the heating time is equal to or higher than the above lower limit, the polyamic acid is imidized to form a polyimide, and most of the above-mentioned development accelerator and photosensitizer are removed. Therefore, the total of the content ratio of the development accelerator and the content ratio of the photosensitizer in the base insulating layer 4 can be adjusted to be equal to or less than the above upper limit. Further, when the heating temperature is not more than the above upper limit, the sum of the content ratio of the development accelerator and the content ratio of the photosensitizer in the base insulating layer 4 can be secured to be more than the above lower limit.
　これによって、ポリイミドを含有するベース絶縁層４が、金属支持体１９上に形成される。 As a result, the base insulating layer 4 containing polyimide is formed on the metal support 19.
　続いて、図３Ｂに示すように、導体パターン形成工程では、導体パターン５を、上記したパターンで、ベース絶縁層４の上面（他方面４Ｂ）と、第１開口部７および第２開口部８から露出する金属支持体１９の上面とに、例えば、アディティブ法などによって形成する。 Subsequently, as shown in FIG. 3B, in the conductor pattern forming step, the conductor pattern 5 is formed in the above-mentioned pattern with the upper surface (the other surface 4B) of the base insulating layer 4 and the first opening 7 and the second opening 8. It is formed on the upper surface of the metal support 19 exposed from, for example, by an additive method or the like.
　これによって、複数の第１端子１０と、複数の第２端子１１と、複数の配線９とが一括して形成される。第１端子１０は、第１開口部７内に配置され、金属支持体１９の上面と接触する。第２端子１１は、図示しないが、第２開口部８内に配置され、金属支持体１９の上面と接触する。これによって、第１端子１０および第２端子１１は、ベース絶縁層４の一方面４Ａに配置される。また、配線９は、ベース絶縁層４の他方面４Ｂに配置される。 As a result, the plurality of first terminals 10, the plurality of second terminals 11, and the plurality of wirings 9 are collectively formed. The first terminal 10 is arranged in the first opening 7 and comes into contact with the upper surface of the metal support 19. Although not shown, the second terminal 11 is arranged in the second opening 8 and comes into contact with the upper surface of the metal support 19. As a result, the first terminal 10 and the second terminal 11 are arranged on one surface 4A of the base insulating layer 4. Further, the wiring 9 is arranged on the other surface 4B of the base insulating layer 4.
　続いて、図３Ｃに示すように、カバー絶縁層形成工程では、カバー絶縁層６を、導体パターン５を被覆するように、ベース絶縁層４の上面（他方面４Ｂ）に形成する。カバー絶縁層形成工程は、ベース絶縁層形成工程と同様に実施できる。 Subsequently, as shown in FIG. 3C, in the cover insulating layer forming step, the cover insulating layer 6 is formed on the upper surface (the other surface 4B) of the base insulating layer 4 so as to cover the conductor pattern 5. The cover insulating layer forming step can be carried out in the same manner as the base insulating layer forming step.
　続いて、図３Ｄに示すように、金属支持体除去工程では、金属支持体１９を除去する。 Subsequently, as shown in FIG. 3D, the metal support 19 is removed in the metal support removing step.
　金属支持体１９の除去方法として、例えば、金属支持体１９をベース絶縁層４の下面（一方面４Ａ）から剥離する方法、例えば、金属支持体１９をエッチング（例えば、ドライエッチング、ウェットエッチングなど）する方法などが挙げられる。 As a method for removing the metal support 19, for example, a method of peeling the metal support 19 from the lower surface (one surface 4A) of the base insulating layer 4, for example, etching the metal support 19 (for example, dry etching, wet etching, etc.). How to do it.
　金属支持体１９の除去方法のなかでは、好ましくは、エッチング、さらに好ましくは、ウェットエッチングが挙げられる。 Among the methods for removing the metal support 19, etching is preferable, and wet etching is more preferable.
　金属支持体１９をウェットエッチングする場合、エッチング液として、例えば、塩化第二鉄溶液などが使用される。そして、例えば、金属支持体１９に対して厚み方向の一方側から、エッチング液をスプレーして、金属支持体１９を除去する。 When the metal support 19 is wet-etched, for example, a ferric chloride solution is used as the etching solution. Then, for example, the metal support 19 is removed by spraying the etching solution from one side in the thickness direction with respect to the metal support 19.
　すると、ベース絶縁層４の一方面４Ａと、第１端子１０の一方面１０Ａと、第２端子１１の一方面（図示せず）とが露出される。 Then, one surface 4A of the base insulating layer 4, one surface 10A of the first terminal 10, and one surface (not shown) of the second terminal 11 are exposed.
　以上によって、ベース絶縁層４と、導体パターン５と、カバー絶縁層６とを備える実装基板１が製造される。 From the above, the mounting substrate 1 including the base insulating layer 4, the conductor pattern 5, and the cover insulating layer 6 is manufactured.
　３．実装基板に対する撮像素子の実装方法
　このような実装基板１は、例えば、撮像素子が実装されて、カメラモジュールなどの撮像装置に備えられる。 3. 3. Method of Mounting an Image Sensor on a Mounting Board Such a mounting board 1 is provided with, for example, an image pickup device such as a camera module on which an image pickup device is mounted.
　次に、図４Ｅおよび図４Ｆを参照して、実装基板１に対する撮像素子２１の実装方法を説明する。 Next, a method of mounting the image pickup device 21 on the mounting board 1 will be described with reference to FIGS. 4E and 4F.
　実装基板１に対する撮像素子２１の実装方法は、素子接続工程と、アンダーフィル形成工程とを含む。 The method of mounting the image pickup device 21 on the mounting board 1 includes an element connection step and an underfill forming step.
　図４Ｅに示すように、素子接続工程では、まず、撮像素子２１を準備する。 As shown in FIG. 4E, in the element connection step, first, the image sensor 21 is prepared.
　撮像素子２１は、光を電気信号に変換する半導体素子であって、例えば、ＣＭＯＳセンサ、ＣＣＤセンサなどの固体撮像素子が挙げられる。撮像素子２１は、平面視略矩形の平板形状に形成されており、図示しないが、Ｓｉ基板などのシリコンと、その上に配置されるフォトダイオード（光電変換素子）およびカラーフィルターとを備える。撮像素子２１は、複数の端子２５を備える。複数の端子２５は、複数の第１端子１０と対応する。 The image sensor 21 is a semiconductor element that converts light into an electric signal, and examples thereof include solid-state image sensors such as CMOS sensors and CCD sensors. The image pickup device 21 is formed in a flat plate shape having a substantially rectangular shape in a plan view, and includes silicon such as a Si substrate, a photodiode (photoelectric conversion element) arranged on the silicon substrate, and a color filter (not shown). The image sensor 21 includes a plurality of terminals 25. The plurality of terminals 25 correspond to the plurality of first terminals 10.
　そして、実装基板１の第１端子１０上にソルダーバンプなどの接合材料２６を配置し、実装基板１の第１端子１０と撮像素子２１の端子２５とを、接合材料２６を介して電気的に接続する。 Then, a bonding material 26 such as a solder bump is arranged on the first terminal 10 of the mounting board 1, and the first terminal 10 of the mounting board 1 and the terminal 25 of the image sensor 21 are electrically connected via the bonding material 26. Connecting.
　これによって、撮像素子２１は、実装基板１のハウジング配置部２の中央部に配置され、実装基板１にフリップチップ実装される。このとき、撮像素子２１は、ベース絶縁層４の一方面４Ａに対して厚み方向の一方側に間隔を空けて位置する。 As a result, the image sensor 21 is arranged at the center of the housing arrangement portion 2 of the mounting substrate 1, and is flip-chip mounted on the mounting substrate 1. At this time, the image pickup device 21 is located on one side in the thickness direction with a distance from the one side surface 4A of the base insulating layer 4.
　次いで、図４Ｆに示すように、アンダーフィル形成工程では、撮像素子２１とベース絶縁層４との間に、第２絶縁層の一例としてのアンダーフィル層１８を形成する。 Next, as shown in FIG. 4F, in the underfill forming step, an underfill layer 18 as an example of the second insulating layer is formed between the image pickup device 21 and the base insulating layer 4.
　具体的には、液状の樹脂組成物を、撮像素子２１とベース絶縁層４の一方面４Ａとの間に注入した後、加熱硬化させる。 Specifically, a liquid resin composition is injected between the image pickup device 21 and one surface 4A of the base insulating layer 4, and then heat-cured.
　アンダーフィル層１８の材料として、例えば、エポキシ樹脂、ポリウレタン樹脂、シリコーン樹脂、ポリエステル樹脂などの樹脂材料が挙げられ、好ましくは、エポキシ樹脂が挙げられる。アンダーフィル層１８の材料は、単独使用または２種以上併用することができる。 Examples of the material of the underfill layer 18 include resin materials such as epoxy resin, polyurethane resin, silicone resin, and polyester resin, and epoxy resin is preferable. The material of the underfill layer 18 can be used alone or in combination of two or more.
　加熱温度は、アンダーフィル層１８の材料に応じて適宜変更されるが、例えば、１００℃以上、好ましくは、１２０℃以上、例えば、１５０℃以下、好ましくは、１３０℃以下である。 The heating temperature is appropriately changed depending on the material of the underfill layer 18, but is, for example, 100 ° C. or higher, preferably 120 ° C. or higher, for example, 150 ° C. or lower, preferably 130 ° C. or lower.
　加熱時間は、アンダーフィル層１８の材料に応じて適宜変更されるが、例えば、１０分以上、好ましくは、３０分以上、例えば、１２０分以下、好ましくは、６０分以下である。 The heating time is appropriately changed depending on the material of the underfill layer 18, but is, for example, 10 minutes or more, preferably 30 minutes or more, for example, 120 minutes or less, preferably 60 minutes or less.
　これによって、アンダーフィル層１８が、撮像素子２１とベース絶縁層４の一方面４Ａとの間に形成される。言い換えれば、アンダーフィル層１８は、ベース絶縁層４の一方面４Ａに配置される。つまり、撮像素子２１が実装された実装基板１は、アンダーフィル層１８を備える。 As a result, the underfill layer 18 is formed between the image pickup device 21 and the one surface 4A of the base insulating layer 4. In other words, the underfill layer 18 is arranged on one surface 4A of the base insulating layer 4. That is, the mounting substrate 1 on which the image pickup device 21 is mounted includes the underfill layer 18.
　以上によって、実装基板１に対する撮像素子２１の実装が完了する。なお、実装基板１と、撮像素子２１と、アンダーフィル層１８とは、撮像ユニット２７を構成する。 With the above, the mounting of the image sensor 21 on the mounting board 1 is completed. The mounting substrate 1, the image sensor 21, and the underfill layer 18 form an image pickup unit 27.
　また、実装基板１は、後述する撮像装置ではなく、撮像装置の一部品、すなわち、撮像装置を作製するための部品であり、産業上利用可能なデバイスである。実装基板１は、撮像素子を含まない部品単独で流通してもよく、撮像素子が実装された撮像ユニットとして流通してもよい。 Further, the mounting substrate 1 is not an image pickup device described later, but a component of the image pickup device, that is, a component for manufacturing the image pickup device, and is an industrially applicable device. The mounting substrate 1 may be distributed as a single component that does not include an image sensor, or may be distributed as an image pickup unit on which an image sensor is mounted.
　４．撮像装置
　次に、図５を参照して、撮像ユニット２７を備える撮像装置２０を説明する。 4. Imaging Device Next, an imaging device 20 including an imaging unit 27 will be described with reference to FIG.
　撮像装置２０は、撮像ユニット２７と、ハウジング２２と、光学レンズ２３と、フィルター２４とを備える。 The image pickup device 20 includes an image pickup unit 27, a housing 22, an optical lens 23, and a filter 24.
　撮像ユニット２７は、実装基板１と、撮像素子２１と、アンダーフィル層１８とを備える。 The image pickup unit 27 includes a mounting substrate 1, an image pickup element 21, and an underfill layer 18.
　ハウジング２２は、実装基板１のハウジング配置部２に、撮像素子２１と間隔を隔てて囲むように配置されている。ハウジング２２は、平面視略矩形状の筒状を有している。 The housing 22 is arranged in the housing arrangement portion 2 of the mounting substrate 1 so as to surround the housing 22 with a distance from the image sensor 21. The housing 22 has a tubular shape having a substantially rectangular shape in a plan view.
　光学レンズ２３は、厚み方向において、撮像素子２１に対して実装基板１の反対側に間隔を隔てて配置される。光学レンズ２３は、平面視略円形状に形成され、外部からの光が撮像素子２１に到達するように、ハウジング２２に固定される。 The optical lens 23 is arranged on the opposite side of the mounting substrate 1 with respect to the image pickup element 21 at intervals in the thickness direction. The optical lens 23 is formed in a substantially circular shape in a plan view, and is fixed to the housing 22 so that light from the outside reaches the image pickup device 21.
　フィルター２４は、厚み方向における撮像素子２１と光学レンズ２３との間に、これらと間隔を隔てて配置され、ハウジング２２に固定される。 The filter 24 is arranged between the image sensor 21 and the optical lens 23 in the thickness direction at intervals from the image sensor 21, and is fixed to the housing 22.
　本発明者らは、図４Ｆに示すように、撮像装置２０（撮像ユニット２７）が湿熱条件下（例えば、１００℃以上、相対湿度８０％以上）に置かれた場合、ベース絶縁層４に対するアンダーフィル層１８の密着性が低下するという知見を得た。 As shown in FIG. 4F, the present inventors under the base insulating layer 4 when the imaging device 20 (imaging unit 27) is placed under moist heat conditions (for example, 100 ° C. or higher and relative humidity 80% or higher). It was found that the adhesion of the fill layer 18 is reduced.
　そこで、本発明者らは、当該知見について種々検討し、湿熱条件下におけるアンダーフィル層１８の密着性の低下は、ベース絶縁層４における現像促進剤の含有割合と感光剤の含有割合との総和に依存することを見出し、本発明を完成した。 Therefore, the present inventors have examined various findings, and the decrease in the adhesion of the underfill layer 18 under moist heat conditions is the sum of the content ratio of the development accelerator and the content ratio of the photosensitizer in the base insulating layer 4. The present invention was completed by finding that it depends on.
　図４Ｆに示すように、実装基板１では、ベース絶縁層４における現像促進剤の含有割合と感光剤の含有割合との総和が上記下限以上である。そのため、撮像装置２０（撮像ユニット２７）が湿熱条件下に置かれた場合であっても、ベース絶縁層４に対するアンダーフィル層１８の密着性の低下を抑制できる。 As shown in FIG. 4F, in the mounting substrate 1, the sum of the content ratio of the development accelerator and the content ratio of the photosensitizer in the base insulating layer 4 is equal to or higher than the above lower limit. Therefore, even when the image pickup apparatus 20 (imaging unit 27) is placed under moist heat conditions, it is possible to suppress a decrease in the adhesion of the underfill layer 18 to the base insulating layer 4.
　また、ベース絶縁層４における現像促進剤の含有割合と感光剤の含有割合との総和は、上記上限以下である。そのため、実装基板１に実装した撮像素子２１を、実装基板１から取り外してリワークする場合、アンダーフィル層１８をベース絶縁層４から引き剥がすことができる。その結果、撮像素子２１のリワーク性を確保することができる。 Further, the total of the content ratio of the development accelerator and the content ratio of the photosensitizer in the base insulating layer 4 is not more than the above upper limit. Therefore, when the image pickup device 21 mounted on the mounting board 1 is removed from the mounting board 1 and reworked, the underfill layer 18 can be peeled off from the base insulating layer 4. As a result, the reworkability of the image sensor 21 can be ensured.
　また、現像促進剤は、イミドアクリレート化合物および／またはポリエチレングリコール化合物を含む。そのため、ベース絶縁層４における現像促進剤の含有割合と感光剤の含有割合との総和を上記範囲に調整できながら、ポリイミド前駆体と、現像促進剤と、感光剤とを含有するワニスの感光性を確保できる。 The development accelerator also contains an imide acrylate compound and / or a polyethylene glycol compound. Therefore, while the sum of the content ratio of the development accelerator and the content ratio of the photosensitizer in the base insulating layer 4 can be adjusted within the above range, the photosensitivity of the varnish containing the polyimide precursor, the development accelerator, and the photosensitizer Can be secured.
　また、実装基板１の製造方法では、図３Ａ～図３Ｄに示すように、金属支持体１９上に、ポリイミド前駆体と、現像促進剤と、感光剤とを含有するワニスを塗布した後、ワニス（ベース被膜）を露光および現像し、次いで、ワニス（ベース被膜）を上記加熱温度かつ上記加熱時間に加熱して、ベース絶縁層４を形成する。 Further, in the method for manufacturing the mounting substrate 1, as shown in FIGS. 3A to 3D, a varnish containing a polyimide precursor, a development accelerator, and a photosensitizer is applied onto the metal support 19, and then the varnish is used. The (base coating) is exposed and developed, and then the varnish (base coating) is heated to the above heating temperature and the above heating time to form the base insulating layer 4.
　そのため、ベース絶縁層４における現像促進剤の含有割合と感光剤の含有割合との総和を、上記の範囲に調整することができる。その結果、簡易な方法でありながら、上記した実装基板１を効率よく製造することができる。 Therefore, the total of the content ratio of the development accelerator and the content ratio of the photosensitizer in the base insulating layer 4 can be adjusted within the above range. As a result, the above-mentioned mounting substrate 1 can be efficiently manufactured by a simple method.
　＜変形例＞
　上記した実施形態では、本発明の配線回路基板として、撮像素子２１を実装するための撮像素子実装基板１（実装基板１）を説明しているが、配線回路基板の用途は、これに限定されない。例えば、スマートフォン、パソコン、ゲーム機などに用いられるＦＰＣなどに好適に用いられる。 <Modification example>
In the above-described embodiment, the image pickup device mounting board 1 (mounting board 1) for mounting the image pickup device 21 is described as the wiring circuit board of the present invention, but the application of the wiring circuit board is not limited to this. .. For example, it is suitably used for FPCs used in smartphones, personal computers, game machines, and the like.
　また、実装基板１では、厚み方向に互いに隣り合う層が、接着剤なしに接着される接着剤レスのＦＰＣであるが、これに限定されない。厚み方向に互いに隣り合う層の間に接着剤層を設けることもできる。一方、薄型化の観点から、上記の実施形態のように、実装基板１は、接着剤レスのＦＰＣであることが好ましい。 Further, in the mounting substrate 1, layers adjacent to each other in the thickness direction are adhesive-less FPCs that are adhered without an adhesive, but the present invention is not limited to this. An adhesive layer may be provided between layers adjacent to each other in the thickness direction. On the other hand, from the viewpoint of thinning, it is preferable that the mounting substrate 1 is an adhesive-less FPC as in the above embodiment.
　また、実装基板１は、図２に示すように、ベース絶縁層４、導体パターン５およびカバー絶縁層６を備えるが、実装基板１の構成は、これに限定されない。例えば、実装基板１は、カバー絶縁層６の厚み方向一方側に配置され、外部からの電磁波を遮断するシールド層と、シールド層を被覆する第２カバー絶縁層とをさらに備えてもよい。 Further, as shown in FIG. 2, the mounting board 1 includes a base insulating layer 4, a conductor pattern 5, and a cover insulating layer 6, but the configuration of the mounting board 1 is not limited to this. For example, the mounting substrate 1 may be further provided with a shield layer that is arranged on one side of the cover insulating layer 6 in the thickness direction and blocks electromagnetic waves from the outside, and a second cover insulating layer that covers the shield layer.
　また、撮像装置２０では、図５に示すように、撮像素子２１は、実装基板１にフリップチップ実装されているが、実装基板１にワイヤボンディングによって実装することもできる。 Further, in the image pickup apparatus 20, as shown in FIG. 5, the image pickup element 21 is flip-chip mounted on the mounting board 1, but can also be mounted on the mounting board 1 by wire bonding.
　このような変形例においても、上記した実施形態と同様の作用効果を奏する。また、上記した実施形態と変形例とは適宜組み合わせることができる。 Even in such a modified example, the same effect as that of the above-described embodiment is obtained. Moreover, the above-described embodiment and the modified example can be appropriately combined.
　以下に参考実施例および参考比較例を示し、本発明をさらに具体的に説明する。なお、本発明は、参考実施例および参考比較例に限定されない。また、以下の記載において用いられる配合割合（含有割合）、物性値、パラメータなどの具体的数値は、上記の「発明を実施するための形態」において記載されている、それらに対応する配合割合（含有割合）、物性値、パラメータなど該当記載の上限（「以下」、「未満」として定義されている数値）または下限（「以上」、「超過」として定義されている数値）に代替することができる。 A reference example and a reference comparative example are shown below, and the present invention will be described in more detail. The present invention is not limited to Reference Examples and Reference Comparative Examples. In addition, specific numerical values such as the compounding ratio (content ratio), physical property values, and parameters used in the following description are described in the above-mentioned "Form for carrying out the invention", and the compounding ratios corresponding to them ( Substitute for the upper limit (numerical value defined as "less than or equal to" or "less than") or lower limit (numerical value defined as "greater than or equal to" or "excess") such as content ratio), physical property value, parameter, etc. it can.
　　製造例１
　２，２’－ビス（トリフルオロメチル）－４，４’－ジアミノビフェニル（ＴＦＭＢ、ハロアルキル基を置換基として有する芳香族ジアミン）４．０ｇ（２０ｍｍｏｌ）と、ｐ－フェニレンジアミン（ＰＰＤ、芳香族ジアミン）８．６５ｇ（８０ｍｍｏｌ）とを５００ｍｌのセパラブルフラスコに投入し、２００ｇの脱水されたＮ－メチル－２－ピロリドン（ＮＭＰ）に溶解させ窒素気流下、オイルバスによって液温が５０℃になるように熱電対でモニターし加熱しながら撹拌した。それらが完全に溶解したことを確認した後、そこへ、３０分かけて３，３’、４，４’－ビフェニルテトラカルボン酸二無水物（ＢＰＤＡ、芳香族酸二無水物）２９．４ｇ（１００ｍｍｏｌ）をセパラブルフラスコに配合した後、５０℃で５時間撹拌した、その後室温まで冷却して、ポリイミド前駆体溶液を得た。 Manufacturing example 1
2,2'-bis (trifluoromethyl) -4,4'-diaminobiphenyl (TFMB, aromatic diamine having a haloalkyl group as a substituent) 4.0 g (20 mmol) and p-phenylenediamine (PPD, aromatic) 8.65 g (80 mmol) of diamine) was placed in a 500 ml separable flask, dissolved in 200 g of dehydrated N-methyl-2-pyrrolidone (NMP), and the liquid temperature was raised to 50 ° C. by an oil bath under a nitrogen stream. It was monitored with a thermocouple so as to be, and stirred while heating. After confirming that they were completely dissolved, 29.4 g (BPDA, aromatic dianhydride) of 3,3', 4,4'-biphenyltetracarboxylic dianhydride (BPDA, aromatic dianhydride) was added to the solution over 30 minutes. (100 mmol) was added to a separable flask, and the mixture was stirred at 50 ° C. for 5 hours and then cooled to room temperature to obtain a polyimide precursor solution.
　次いで、ポリイミド前駆体溶液に、ポリイミド前駆体溶液の固形分（ポリアミド酸）１００質量部に対して、ｎ－アクリロイルオキシエチルヘキサヒドロフタルイミド（現像促進剤）７４質量部と、１－エチル－３，５－ジメトキシカルボニル－４－（２－ニトロフェニル）－１，４－ジヒドロピリジン（感光剤）１４質量部とを添加して、ワニスを調製した。 Next, in the polyimide precursor solution, 74 parts by mass of n-acryloyloxyethyl hexahydrophthalimide (development accelerator) and 1-ethyl-3, with respect to 100 parts by mass of the solid content (polyamic acid) of the polyimide precursor solution. A varnish was prepared by adding 14 parts by mass of 5-dimethoxycarbonyl-4- (2-nitrophenyl) -1,4-dihydropyridine (photosensitizer).
　参考実施例１、２および参考比較例１
　ステンレスを材料とする金属支持体を準備し、製造例１において調製されたワニスを金属支持体の上面に塗布し、次いで、８０℃で１０分乾燥させて、ベース皮膜（ポリイミド前駆体皮膜）を形成した。 Reference Examples 1 and 2 and Reference Comparative Example 1
A metal support made of stainless steel is prepared, the varnish prepared in Production Example 1 is applied to the upper surface of the metal support, and then dried at 80 ° C. for 10 minutes to form a base film (polyimide precursor film). Formed.
　続いて、ベース皮膜を、露光および現像した後、窒素雰囲気下、表１に示す加熱温度および加熱時間にて硬化させた。これにより、ポリイミドを含有するベース絶縁層を形成した。 Subsequently, the base film was exposed and developed, and then cured under a nitrogen atmosphere at the heating temperature and heating time shown in Table 1. As a result, a base insulating layer containing polyimide was formed.
　次いで、金属支持体に対して塩化第二鉄水溶液（エッチング液）をスプレーして、金属支持体を除去した。これによって、ベース絶縁層の一方面を露出させた。 Next, the metal support was removed by spraying an aqueous solution of ferric chloride (etching solution) on the metal support. As a result, one side of the base insulating layer was exposed.
　以上により、ベース絶縁層を得た。 From the above, a base insulating layer was obtained.
　各ベース絶縁層において、現像促進剤の含有割合と感光剤の含有割合との総和を測定した。その結果を表１に示す。 In each base insulating layer, the total of the content ratio of the development accelerator and the content ratio of the photosensitizer was measured. The results are shown in Table 1.
　また、すべてのベース絶縁層の硬化が完了していることを、ＦＴ－ＩＲにより確認した。 In addition, it was confirmed by FT-IR that the curing of all the base insulating layers was completed.
　参考比較例２
　カプトン１００Ｈ（デュポン社製）を、ベース絶縁層として準備した。カプトン１００Ｈには、現像促進剤および感光剤が含有されていなかった。 Reference comparison example 2
Kapton 100H (manufactured by DuPont) was prepared as a base insulating layer. Kapton 100H did not contain a development accelerator and a photosensitizer.
　＜アンダーフィル層の初期密着力＞
　各参考実施例および各参考比較例のベース絶縁層の一方面に、アンダーフィル層を形成して、ベース絶縁層に対するアンダーフィル層の初期密着力を測定した。 <Initial adhesion of underfill layer>
An underfill layer was formed on one surface of the base insulating layer of each reference example and each reference comparative example, and the initial adhesion of the underfill layer to the base insulating layer was measured.
　具体的には、ＰＣＴ試験後のベース絶縁層の一方面に、液状のエポキシ樹脂組成物を塗布し、次いで、１２５℃で１０分乾燥させて、アンダーフィル層を形成した。アンダーフィル層の厚みは、約４０μｍであった。 Specifically, a liquid epoxy resin composition was applied to one surface of the base insulating layer after the PCT test, and then dried at 125 ° C. for 10 minutes to form an underfill layer. The thickness of the underfill layer was about 40 μm.
　次いで、アンダーフィル層におけるベース絶縁層と反対側の面に、両面テープ（Ｎｏ．５０００ｎｓ、日東電工社製）を貼り付けて、積層体を準備した。積層体は、ベース絶縁層と、アンダーフィル層と、両面テープとを厚み方向に順に備える。 Next, a double-sided tape (No. 5000ns, manufactured by Nitto Denko Corporation) was attached to the surface of the underfill layer opposite to the base insulating layer to prepare a laminate. The laminate includes a base insulating layer, an underfill layer, and double-sided tape in this order in the thickness direction.
　次いで、積層体を５ｍｍ幅の平帯状にカットし、積層体を、両面テープによって、下記装置が備える試料台に固定した。試料台は、回転可能に支持される円柱形状を有し、試料台の外径は、２０ｃｍであった。また、積層体は、試料台の周面に接着された。 Next, the laminate was cut into a flat band having a width of 5 mm, and the laminate was fixed to the sample table provided with the following device with double-sided tape. The sample table had a cylindrical shape that was rotatably supported, and the outer diameter of the sample table was 20 cm. Further, the laminated body was adhered to the peripheral surface of the sample table.
　次いで、ベース絶縁層を、下記条件において、アンダーフィル層から引き剥がした。その結果を表１に示す。 Next, the base insulating layer was peeled off from the underfill layer under the following conditions. The results are shown in Table 1.
　　装置；ＳＶＺ－５０ＮＢ（ＩＭＡＤＡ社製）
　　引張角度；９０°（つまり、引張方向は、試料台の径方向）
　　引張速度；１０ｍｍ／分
　＜アンダーフィル層の湿熱後の密着力低下率＞
　密着力の測定に先立って、各参考実施例および各参考比較例のベース絶縁層に対して、プレッシャークッカー試験（ＰＣＴ試験）を実施した。具体的には、各ベース絶縁層を、１２０℃、相対湿度１００％、圧力１．９ａｔｍの条件下に、１００時間置いた。 Equipment; SVZ-50NB (manufactured by IMADA)
Tensile angle: 90 ° (that is, the tensile direction is the radial direction of the sample table)
Tensile rate: 10 mm / min <Rate of decrease in adhesion of underfill layer after moist heat>
Prior to the measurement of the adhesive force, a pressure cooker test (PCT test) was performed on the base insulating layer of each reference example and each reference comparative example. Specifically, each base insulating layer was placed under the conditions of 120 ° C., 100% relative humidity, and 1.9 atm pressure for 100 hours.
　その後、上記と同様にして、ＰＣＴ試験後のベース絶縁層の一方面にアンダーフィル層を形成して、ＰＣＴ試験後のベース絶縁層に対するアンダーフィル層の密着力を測定した。そして、ＰＣＴ試験後のアンダーフィル層の密着力の低下率（ＰＣＴ試験後の密着力／初期密着力）を算出した。その結果を表１に示す。 After that, in the same manner as above, an underfill layer was formed on one surface of the base insulating layer after the PCT test, and the adhesion of the underfill layer to the base insulating layer after the PCT test was measured. Then, the rate of decrease in the adhesion of the underfill layer after the PCT test (adhesion after the PCT test / initial adhesion) was calculated. The results are shown in Table 1.
Figure JPOXMLDOC01-appb-T000007
Figure JPOXMLDOC01-appb-T000007
　＜考察＞
　表１に示されるように、ベース絶縁層における現像促進剤の含有割合と感光剤の含有割合との総和が５０ｐｐｍ以下である参考実施例１は、ベース絶縁層における現像促進剤の含有割合と感光剤の含有割合との総和が５０ｐｐｍを超過する参考比較例１と比較して、ＰＣＴ試験後（つまり、湿熱条件下に置かれた後）におけるベース絶縁層に対するアンダーフィル層の密着力の低下が顕著に抑制されている。 <Discussion>
As shown in Table 1, in Reference Example 1 in which the sum of the content ratio of the development accelerator and the content ratio of the photosensitizer in the base insulating layer is 50 ppm or less, the content ratio of the development accelerator and the photosensitivity in the base insulating layer Compared with Reference Comparative Example 1 in which the sum with the content ratio of the agent exceeds 50 ppm, the adhesion of the underfill layer to the base insulating layer after the PCT test (that is, after being placed under moist heat conditions) is reduced. It is significantly suppressed.
　また、参考実施例１は、ベース絶縁層における現像促進剤の含有割合と感光剤の含有割合との総和が５ｐｐｍ以上であり、ベース絶縁層に対するアンダーフィル層の初期密着力が２００ｇｆ／ｃｍ以下に調整されている。なお、参考比較例２のように、密着力が２００ｇｆ／ｃｍを超過すると、電子部品のリワーク時に、アンダーフィル層をベース絶縁層から引き剥がすことが困難である。この点、参考実施例１は、密着力が１００ｇｆ／ｃｍ以下であり、電子部品のリワーク性を確保できる。 Further, in Reference Example 1, the total of the content ratio of the development accelerator and the content ratio of the photosensitizer in the base insulating layer is 5 ppm or more, and the initial adhesion of the underfill layer to the base insulating layer is 200 gf / cm or less. It has been adjusted. If the adhesion exceeds 200 gf / cm as in Reference Comparative Example 2, it is difficult to peel off the underfill layer from the base insulating layer when the electronic component is reworked. In this respect, in Reference Example 1, the adhesion is 100 gf / cm or less, and the reworkability of the electronic component can be ensured.
　なお、上記発明は、本発明の例示の実施形態として提供したが、これは単なる例示に過ぎず、限定的に解釈してはならない。当該技術分野の当業者によって明らかな本発明の変形例は、後記請求の範囲に含まれる。 Although the above invention has been provided as an exemplary embodiment of the present invention, this is merely an example and should not be construed in a limited manner. Modifications of the present invention that will be apparent to those skilled in the art are included in the claims below.
　本発明の配線回路基板は、例えば、撮像素子実装基板、スマートフォン、パソコン、ゲーム機などに用いられるフレキシブル配線回路基板などの各種用途で用いられる。 The wiring circuit board of the present invention is used in various applications such as an image sensor mounting board, a flexible wiring circuit board used in a smartphone, a personal computer, a game machine, and the like.
　１　　　実装基板
　４　　　ベース絶縁層
　４Ａ　　一方面
　１０　　第１端子
　１８　　アンダーフィル層 1 Mounting board 4 Base insulation layer 4A One side 10 1st terminal 18 Underfill layer

Claims (3)

  1. 　ポリイミドと、現像促進剤と、感光剤とを含有する第１絶縁層と、
    　前記第１絶縁層の厚み方向の一方面に配置される端子と、を備え、
    　前記第１絶縁層における前記現像促進剤の含有割合と前記感光剤の含有割合との総和は、５ｐｐｍ以上５０ｐｐｍ以下であることを特徴とする、配線回路基板。     A first insulating layer containing polyimide, a development accelerator, and a photosensitizer,
    A terminal arranged on one surface in the thickness direction of the first insulating layer is provided.
    A wiring circuit board, wherein the total of the content ratio of the development accelerator and the content ratio of the photosensitizer in the first insulating layer is 5 ppm or more and 50 ppm or less.
  2. 　前記現像促進剤は、イミドアクリレート化合物および／またはポリエチレングリコール化合物を含むことを特徴とする、請求項１に記載の配線回路基板。 The wiring circuit board according to claim 1, wherein the development accelerator contains an imide acrylate compound and / or a polyethylene glycol compound.
  3. 　金属支持層を準備する工程と、
    　前記金属支持層上に、ポリイミドと、現像促進剤と、感光剤とを含有する第１絶縁層を形成する工程と、
    　前記第１絶縁層の前記厚み方向の一方面に端子を形成する工程と、を含み、
    　前記第１絶縁層を形成する工程は、
    　　前記金属支持層上に、ポリイミド前駆体と、現像促進剤と、感光剤とを含有するワニスを塗布する工程と、
    　　前記ワニスを露光および現像する工程と、
    　　現像後の前記ワニスを、３００℃以上４００℃以下に、１００分以上加熱する工程と、を含むことを特徴とする、配線回路基板の製造方法。     The process of preparing the metal support layer and
    A step of forming a first insulating layer containing a polyimide, a development accelerator, and a photosensitizer on the metal support layer.
    A step of forming a terminal on one surface of the first insulating layer in the thickness direction is included.
    The step of forming the first insulating layer is
    A step of applying a varnish containing a polyimide precursor, a development accelerator, and a photosensitizer onto the metal support layer.
    The steps of exposing and developing the varnish,
    A method for manufacturing a wiring circuit board, which comprises a step of heating the developed varnish to 300 ° C. or higher and 400 ° C. or lower for 100 minutes or longer.
PCT/JP2020/016550 2019-07-09 2020-04-15 Wiring circuit board and method for producing wiring circuit board WO2021005863A1 (en)

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Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2004177864A (en) * 2002-11-29 2004-06-24 Nitto Denko Corp Process for producing polyimide optical waveguide
JP2011085713A (en) * 2009-10-14 2011-04-28 Nitto Denko Corp Photosensitive resin composition, method for manufacturing circuit board with metal support using the same, and the circuit board with the metal support
WO2018199129A1 (en) * 2017-04-28 2018-11-01 日東電工株式会社 Flexible wiring circuit board, and manufacturing method thereof and imaging device

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2004177864A (en) * 2002-11-29 2004-06-24 Nitto Denko Corp Process for producing polyimide optical waveguide
JP2011085713A (en) * 2009-10-14 2011-04-28 Nitto Denko Corp Photosensitive resin composition, method for manufacturing circuit board with metal support using the same, and the circuit board with the metal support
WO2018199129A1 (en) * 2017-04-28 2018-11-01 日東電工株式会社 Flexible wiring circuit board, and manufacturing method thereof and imaging device

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