JP2010138422A - Metal foil having functional film, flexible metal covered layered plate, electronic component mounting module, and method for manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a metal foil member which is formed using a conductive metal foil having a flat surface without any surface roughing treatment, and improved in adhesiveness to an organic base material or an anisotropic conductive film. <P>SOLUTION: In the metal foil with a functional film having an insulating functional film 2 on one side of the conductive metal foil 1, the insulating functional film is formed by using a coating liquid containing a condensation product having a main backbone of a repetitive unit of M-O in which a metal alkoxide compound expressed by a general formula (I) R<SP>1</SP><SB>n</SB>M(OR<SP>2</SP>)<SB>m-n</SB>(wherein R<SP>1</SP>denotes a non-hydrolytic group; R<SP>2</SP>denotes a 1-6C alkyl group; M denotes a metal atom selected from among silicon, titanium, zirconium, and aluminum; m denotes the valency of the metal atom M, i.e. 3 or 4; and n denotes an integer of 0 to 2 when m is 4, and an integer of 0 to 1 when m is 3) is subjected to the hydrolysis and condensation reaction. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a metal foil with a functional film, a flexible metal-clad laminate using the same, an electronic component mounting module, and a method for manufacturing the same. More specifically, the present invention relates to a metal foil with a functional film capable of laminating a metal foil with good adhesion on an insulating organic substrate such as a heat-fusible polyimide film, at least one surface of the insulating organic substrate. In addition, a flexible metal-clad laminate in which metal foils are laminated with good adhesion, a high-quality electronic component mounting module made using this metal-clad laminate and an anisotropic conductive film, and an efficient production of this module It is about how to do.

  In recent years, with the diversification of electronic devices such as miniaturization and sophistication, the demand for flexible wiring boards is increasing. In this flexible wiring board, a circuit is generally produced on a flexible printed wiring board (metal-clad laminate) in which an electrical insulating film and a metal foil are laminated and integrated via an adhesive if necessary. For protecting the circuit, the cover lay is bonded and cured through a semi-cured adhesive layer and integrated.

  Such flexible wiring boards have flexibility and are used for wiring of electrical equipment and electronic equipment. The required characteristics include adhesiveness, heat resistance, solvent resistance, electrical characteristics, and dimensional stability. And excellent long-term heat resistance.

  Furthermore, in recent years, this flexible wiring board has been frequently used for wiring of repeated bending and sliding portions, like a foldable mobile phone component. Due to the high-density arrangement, there is an increasing demand for the thinness itself, reliability such as bending during use, and incorporation into an extremely narrow gap. Therefore, the flexible wiring board is required to have excellent bending characteristics and bending characteristics as well as its own thinness, in addition to the above required characteristics.

  On the other hand, in recent years, electronic components have been reduced in size, thickness, and performance, and high-density packaging technology has been actively developed. Miniaturization of circuit electrodes is indispensable for high-density mounting of electronic components, and it is difficult to cope with conventional solders and rubber connectors having a minimum corresponding circuit pitch of 100 μm or more. For this reason, anisotropic conductive adhesives having excellent resolution have been frequently used. In this method, for example, when a glass substrate of a liquid crystal display (LCD) and a fine electrode of a TCP (Tape Carrier Package) or FPC (Flexible Print Circuit) are connected to each other, an adhesive containing a predetermined amount of conductive fine particles is used. An anisotropic conductive film (ACF) made of an agent is sandwiched between opposed electrodes and heated and pressurized to electrically connect the two electrodes, and between adjacent electrodes. Is for providing an insulating property, and the electronic component and the electrode are bonded and fixed.

  ACF mounting of electronic components consists of three processes: transfer, alignment, and crimping. First, ACF is attached to one electronic component or substrate. Next, another electronic component or substrate electrode is aligned. Finally, the ACF resin between the electrodes to be connected is eliminated by simultaneously heating at about 150 ° C. to 180 ° C. and pressurizing at about 2 to 3 MPa, and the conductive fine particles are captured between the electrodes, so that the electrodes are electrically Conductive. Thereafter, the electrodes to be connected are physically bonded by curing the ACF resin. At this time, resin flow, resin curing, and electrode connection are performed. The anisotropic conductivity is manifested by optimizing the diameter of the conductive particles and the density of filling the conductive particles with the diameter of 3 to 10 μm for the conduction between the electrodes facing each other and the insulation between the adjacent electrodes (see Non-Patent Document 1).

  By the way, as a flexible metal-clad laminate used for such a flexible wiring board, a copper-clad laminate (CCL) obtained by laminating a polyimide film and a copper foil is generally used. In this copper-clad laminate, since strong adhesion between the copper foil and the polyimide film is required, for example, the copper foil surface is a surface treatment that combines a roughening treatment and a barrier treatment, or a roughening treatment. And surface treatment which combined barrier treatment and rust prevention treatment is performed (refer to patent documents 1). Such surface treatment improves adhesion due to the anchor effect of the copper foil and polyimide film, and even after removing copper by etching, the roughened shape of the copper foil is transferred to the polyimide film surface to form an uneven shape. Is done. Due to this shape, the adhesion with the anisotropic conductive film used after bonding after wiring formation is also secured by the anchor effect and exhibits good adhesion.

  On the other hand, when actually used as a flexible printed wiring material, the frequency of electrical signals has been increased in recent years, and when the copper foil is roughened by the above method, the delay of the transmission signal is reduced. It has become a problem. For this reason, it is necessary to ensure adhesion with the polyimide film while keeping the surface of the copper foil (interface with the polyimide film) in a flat state. In this case, the copper foil surface is treated with a silane coupling agent, etc. Has been proposed to improve the adhesion by developing a chemical interaction with the polyimide film, but in this method, the adhesion between the copper foil and the polyimide film is ensured. The adhesion with the anisotropic conductive film after the etching process is not sufficient.

JP 2003-86936 A MATERIAL STAGE Vol. 7, no. 11 2008

  Under such circumstances, the present invention is a metal foil member having good adhesion to an insulating organic substrate or anisotropic conductive film even when a conductive metal foil having a flat surface is used. A flexible metal-clad laminate in which the metal foil member is laminated with good adhesion on at least one surface of the insulating organic base material, an electronic component mounting module with good quality such as adhesion with an anisotropic conductive film, and the like An object of the present invention is to provide a method for efficiently manufacturing a product.

  As a result of intensive studies to achieve the above-mentioned object, the present inventors have applied a coating containing a condensate obtained by subjecting a surface of a conductive metal foil to a hydrolysis-condensation reaction of a specific metal alkoxide compound. The metal foil with an insulating functional film formed using a liquid can be adapted to the purpose as a metal foil member, and the metal foil with a functional film is provided on at least one surface of the insulating organic substrate. It has been found that a desired flexible metal-clad laminate can be obtained by laminating via a functional film.

Furthermore, the present inventors have found that an electronic component mounting module with good quality can be efficiently obtained by using this flexible metal-clad laminate and an anisotropic conductive film to mount an electronic component by performing a specific process.
The present invention has been completed based on such findings.

That is, the present invention
(1) A metal foil with a functional film having an insulating functional film on one side of a conductive metal foil, wherein the insulating functional film has the general formula (I)
R ¹ _n M (OR ² ) _m−n (I)
Wherein R ¹ is a non-hydrolyzable group, R ² is an alkyl group having 1 to 6 carbon atoms, M is a metal atom selected from silicon, titanium, zirconium and aluminum, and m is a metal atom The valence of M is 3 or 4, and n is an integer of 0 to 2 when m is 4, an integer of 0 to 1 when m is 3, and each R when there are a plurality of R ^{1 1} may be different even identical to each other, if the OR ² there are a plurality, each OR ² may be different even identical to each other.)
A functional film formed by using a coating liquid containing a condensate having a main skeleton of a MO repeating unit obtained by hydrolysis-condensation of a metal alkoxide compound represented by With metal foil,
(2) The metal foil with a functional film according to the above (1), wherein the metal atom M of the metal alkoxide is 2 or more types,
(3) The metal foil with a functional film according to the above (1) or (2), wherein the coating liquid further contains insulating particles,
(4) The metal foil with a functional film according to any one of (1) to (3), wherein the conductive metal foil is a copper foil,
(5) The metal foil with a functional film according to any one of the above (1) to (4) is laminated on at least one surface of the insulating organic base material via the functional film. A flexible metal-clad laminate,
(6) The flexible metal-clad laminate according to (5) above, wherein the insulating organic base material is a heat-fusible polyimide film,
(7) An electronic component mounting module, wherein an electronic component is mounted using the flexible metal-clad laminate and the anisotropic conductive film described in (5) or (6) above, and ( 8) (a) A step of etching the metal foil of the flexible metal-clad laminate described in the above (5) or (6) to form a circuit pattern to produce a flexible wiring board, (b) the flexible A step of temporarily pressing an anisotropic conductive film on a circuit pattern of a wiring board; (c) placing an electronic component on the anisotropic conductive film; and connecting a terminal of the electronic component and a predetermined circuit pattern of the flexible wiring board A step of aligning so that the circuit can be connected, and (d) a step of curing and pressing the matrix resin of the anisotropic conductive film by heat and pressure treatment, Characterized in that it comprises, a manufacturing method of an electronic component mounting module,
Is to provide.

  According to the present invention, a metal foil with a functional film capable of laminating a metal foil with good adhesion on an insulating organic substrate such as a heat-fusible polyimide, a metal on at least one surface of the insulating organic substrate. A flexible metal-clad laminate in which foil is laminated with good adhesion, a flexible wiring board obtained by patterning the metal foil part of this metal-clad laminate, and an anisotropic conductive film, and a high-quality electronic component mounting module, And the method of manufacturing this electronic component mounting module efficiently can be provided.

First, the metal foil with a functional film of the present invention will be described.
[Metal foil with functional film]
The metal foil with a functional film of the present invention is a metal foil with a functional film having an insulating functional film on one side of the conductive metal foil, and the insulating functional film is represented by the following general formula (I): The metal alkoxide compound is formed by using a coating liquid containing a condensate having a main skeleton of MO repeating units formed by hydrolysis-condensation reaction.

(Conductive metal foil)
There is no restriction | limiting in particular as electroconductive metal foil in the metal foil with a functional film of this invention, From the metal foil conventionally used for the metal-clad laminated board, arbitrary things can be selected suitably and can be used. .

  As the metal foil, copper foil, aluminum foil or the like can be used. However, in consideration of subsequent processes such as circuit formation, copper foil is preferable, and the types of copper foil used here are rolled copper foil, electrolytic A copper foil etc. are mentioned and all can be used.

  The thickness of the metal foil used in the present invention is preferably 3 to 35 μm, and more preferably 5 to 18 μm. If the thickness of the metal foil is less than 3 μm, the mechanical properties of the metal foil are lowered, so that the working efficiency is remarkably lowered. If the thickness is more than 35 μm, it becomes difficult to sharpen the metal edge during etching, and a fineness of 100 μm or less. In pattern circuit fabrication, it becomes extremely difficult to adjust to a target circuit pitch.

(Coating fluid)
In the metal foil with a functional film of the present invention, the coating liquid used for forming the functional film is represented by the general formula (I).
R ¹ _n M (OR ² ) _m−n (I)
It is a coating liquid containing the condensate which has as a main skeleton the repeating unit of MO formed by carrying out hydrolysis-condensation reaction of the metal alkoxide compound represented by these.

In the general formula (I), R ¹ is a non-hydrolyzable group such as an alkyl group having 1 to 20 carbon atoms, a (meth) acryloyloxy group, an amino group or an epoxy group, and an alkyl group having 1 to 20 carbon atoms. An alkenyl group, an alkenyl group having 2 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, or an aralkyl group having 7 to 20 carbon atoms is shown. Here, as a C1-C20 alkyl group, a C1-C10 thing is preferable, and this alkyl group may be linear, branched, or cyclic. In addition to this, functional groups containing substituents such as hydroxyl groups, thiols, and imidazoles can also be mentioned.

  Examples of this alkyl group include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, octyl group, cyclopentyl. Group, cyclohexyl group and the like. As a C1-C20 alkyl group which has a (meth) acryloyloxy group, an amino group, or an epoxy group, the C1-C10 alkyl group which has the said substituent is preferable, and this alkyl group is linear, It may be either branched or annular. Examples of the alkyl group having this substituent include γ-acryloyloxypropyl group, γ-methacryloyloxypropyl group, γ-aminopropyl group, 3- (2-aminoethylamino) propyl group, and 3-feraminopropyl group. , Γ-glycidoxypropyl group, 3,4-epoxycyclohexyl group and the like. The alkenyl group having 2 to 20 carbon atoms is preferably an alkenyl group having 2 to 10 carbon atoms, and the alkenyl group may be linear, branched or cyclic. Examples of the alkenyl group include vinyl group, allyl group, butenyl group, hexenyl group, octenyl group and the like. As a C6-C20 aryl group, a C6-C10 thing is preferable, for example, a phenyl group, a tolyl group, a xylyl group, a naphthyl group etc. are mentioned. As a C7-20 aralkyl group, a C7-10 thing is preferable, for example, a benzyl group, a phenethyl group, a phenylpropyl group, a naphthylmethyl group etc. are mentioned.

On the other hand, R ² is an alkyl group having 1 to 6 carbon atoms, which may be linear, branched or cyclic, and examples thereof include a methyl group, an ethyl group, an n-propyl group, and isopropyl. Group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, cyclopentyl group, cyclohexyl group and the like. M represents a metal atom selected from silicon, titanium, zirconium and aluminum, m is a valence of the metal atom M and is 3 or 4, and n is an integer of 0 to 2 when m is 4, When m is 3, it is an integer of 0-1. When R ¹ are a plurality, each R ¹ may be mutually identical or different and, where OR ² there are a plurality, each OR ² may be the mutually the same, or different It may be.

  Examples of the alkoxide compound represented by the above general formula (I), in which M is tetravalent titanium, silicon, zirconium, m is 4, and n is an integer of 0 to 3, , Tetramethoxy titanium, tetraethoxy titanium, tetra-n-propoxy titanium, tetraisopropoxy titanium, tetra-n-butoxy titanium, tetraisobutoxy titanium, tetra-sec-butoxy titanium, tetra-tert-butoxy titanium, methyltrimethoxy Titanium, methyl triethoxy titanium, methyl tripropoxy titanium, methyl triisopropoxy titanium, ethyl trimethoxy titanium, ethyl triethoxy titanium, propyl triethoxy titanium, butyl trimethoxy titanium, phenyl trimethoxy titanium, phenyl triethoxy titanium, vinyl tri Methoxytitanium, vinyltriethoxytitanium, γ-glycidoxypropyltrimethoxytitanium, γ-acryloyloxypropyltrimethoxytitanium, γ-methacryloyloxypropyltrimethoxytitanium, dimethyldimethoxytitanium, methylphenyldimethoxytitanium, and the like in the above compounds Mention may be made of compounds in which titanium is replaced by silane or zirconium.

  Examples of the alkoxide compound represented by the above general formula (I) in which M is trivalent aluminum, m is 3, and n is an integer of 0 to 1 include tri Methoxy aluminum, triethoxy aluminum, tri-n-propoxy aluminum, triisopropoxy aluminum, tri-n-butoxy aluminum, triisobutoxy aluminum, tri-sec-butoxy aluminum, tri-tert-butoxy aluminum, methyl dimethoxy aluminum, methyl Examples include diethoxyaluminum, methyldipropoxyaluminum, ethyldimethoxyaluminum, ethyldiethoxyaluminum, and propyldiethoxyaluminum.

  These alkoxide compounds may be used individually by 1 type, and may be used in combination of 2 or more type.

  The hydrolysis-condensation reaction of the alkoxide compound represented by the general formula (I) is carried out by subjecting the alkoxide compound to water in a polar solvent such as an alcohol, cellosolve, ketone, or ether, particularly preferably isopropanol. Or when water and acid such as hydrochloric acid, sulfuric acid, nitric acid, or a cation exchange resin as a solid acid is used, it is hydrolyzed at a temperature of usually 0-60 ° C., preferably 20-40 ° C., and a solid acid is used. Can be carried out by removing the solvent or adding or removing the solvent, if desired, by the reaction described above, and the reaction can be carried out with the repeating unit of M-O (M is the same as above) as the main skeleton. Thus, a coating liquid containing a condensate having a predetermined concentration can be obtained.

The condensate having the above-mentioned MO repeating unit as the main skeleton has excellent adhesion to a metal foil such as copper foil, and the OH group generated by hydrolysis of OR ² in the general formula (I) remains. Moreover, it is excellent also in the adhesiveness with respect to the matrix resin in organic base materials, such as a polyimide film, and the anisotropic conductive film mentioned later. In the general formula (I), when n is 1 or more, R ¹ is an epoxy-containing group such as γ-glycidoxypropyl group or 3,4-epoxycyclohexyl group, γ-aminopropyl group, 3- ( When 2-aminoethylamino) propyl group or 3-feraminopropyl group is used, since these groups are present in the condensate, adhesion to organic substrates such as polyimide films and anisotropic conductive films is further improved. To do.

  About the density | concentration of the said condensate in the said coating liquid, what is necessary is just a density | concentration which can be coated on metal foil, and there is no restriction | limiting in particular, Usually about 50.0-0.05 mass%, Preferably it is 30.0. It is -0.5 mass%.

<Insulating particles>
The coating liquid can contain insulating particles for the purpose of improving adhesion to a metal foil, an organic base material, an anisotropic conductive film, and the like.

  Insulating particles include silica particles, titania particles, zirconia particles, alumina particles, oxidized particles having an average particle diameter of preferably 10 to 2000 nm, more preferably 50 to 500 nm, from the viewpoint of improving adhesion due to the anchor effect. Zinc particles, yttrium oxide particles, cerium oxide particles, and the like can be used. The said insulating particle may be used individually by 1 type, and may be used in combination of 2 or more type. In order to increase the anchor effect, secondary particles in which particles having a relatively small average particle diameter are aggregated may be used.

  When such a coating liquid containing insulating particles is applied onto a metal foil, an insulating functional film having a concavo-convex shape is formed on the metal foil, and when the insulating liquid is bonded to the insulating organic base material. An anchor effect is imparted to the material, and bonding is performed with good adhesion. In addition, when the metal foil and the insulating organic base material are pressure-bonded by heat, the insulating organic base material to be used, for example, a polyimide film preferably has a thermoplastic resin layer on the surface, and the above organic group is used during the thermo-compression bonding. The surface of the material is plasticized, and the irregular particles of the insulating functional film formed on the surface of the metal foil are embedded in the surface layer of the organic base material.

  As will be described later, when the metal foil is etched to form a wiring, the embedded particles form irregularities on the surface of the organic base material, and the irregularities thus formed thermocompress the anisotropic conductive film. When working, it works as an anchor effect and improves the adhesion between the anisotropic conductive film and the organic substrate. When the aggregated secondary particles are used, the formed uneven shape has a higher order structure and is more effective.

  Further, in order to more actively form a concavo-convex structure on the surface of the insulative organic substrate, the metal film is etched as a condensate by the hydrolysis-condensation reaction, which is a coating film forming component of the coating liquid. A material that is etched simultaneously with the foil can be employed. Thereby, it becomes easy to form the unevenness | corrugation by this particle | grain on the organic base material surface at the time of an etching.

  Further, as the insulating particles to be added, particles etched simultaneously with the metal foil may be used during the etching of the metal foil. In this case, the added insulating particles are simultaneously dissolved during the etching of the metal foil, and irregularities that are symmetrical to the particle shape are formed on the surface of the organic base material, contributing to the anchor effect.

  In order to exhibit such an anchor effect better, the insulating particles to be added preferably have an average particle size larger than the thickness of the functional film formed on the metal foil.

  The content of the insulating particles in the coating liquid is usually 5 to 900 with respect to 100 parts by mass of the hydrolysis-condensate of the metal alkoxide represented by the general formula (I) from the viewpoint of the anchor effect and the like. About part by mass, preferably 20 to 500 parts by mass.

  The method for coating the coating liquid on the metal foil is not particularly limited, and conventionally known methods such as spin coating, spray coating, bar coating, knife coating, roll coating, blade coating, A desired functional film can be formed by coating by a die coating method, a gravure coating method, etc., forming a film, and then naturally drying or heat drying. The thickness of the functional film is usually about 0.01 to 3.00 μm, preferably 0.05 to 1.00 μm.

(Component gradient film)
In the metal foil with a functional film of the present invention, a component gradient film as shown below can be formed on the metal foil as the functional film.

  In this component gradient film, the metal foil side is substantially a metal oxide component, and the opposite side (open surface side) is substantially an organic polymer compound component, and the content ratio of both is continuously changed in the film thickness direction. It is a functional film having a component gradient structure.

  Such a component gradient film has good adhesion to the metal foil, and also good adhesion to the insulating organic substrate and adhesion to the anisotropic conductive film.

  The component gradient film includes, for example, (A) an organic polymer compound having a metal-containing group capable of binding to a metal oxide by hydrolysis in the molecule, and (B) a metal-containing compound capable of forming a metal oxide by hydrolysis. Can be formed using a coating agent obtained by hydrolyzing.

  The organic polymer compound having a hydrolyzable metal-containing group as the component (A) includes, for example, (a) an ethylenically unsaturated monomer having a hydrolyzable metal-containing group, and (b) an ethylenic material not containing a metal. It can be obtained by copolymerizing unsaturated monomers.

  On the other hand, examples of the metal-containing compound capable of forming a metal oxide by hydrolysis of the component (B) include tetraalkoxysilanes, tetraalkoxytitaniums, tetraalkoxyzirconiums, trialkoxyaluminums and the like.

  In addition, about the said coating agent, the detail is described in Unexamined-Japanese-Patent No. 2000-336281.

  The metal foil with a functional film of the present invention thus produced is a material for producing a flexible metal-clad laminate obtained by laminating the following metal foils with good adhesion and an electronic component mounting module with good quality. Can be used as

[Flexible metal-clad laminate]
The flexible metal-clad laminate of the present invention (hereinafter sometimes simply referred to as a metal-clad laminate) is obtained by applying the above-described metal foil with a functional film of the present invention to at least one surface of an insulating organic substrate. It is characterized by being laminated through.

(Insulating organic base material)
There is no particular limitation on the insulating organic substrate used in the metal-clad laminate of the present invention, and any one of the insulating organic substrates conventionally used in metal-clad laminates can be appropriately selected and used. Can do. Examples of such an insulating organic substrate include a polyimide film, a polyester film, a polyparabanic acid film, a polyphenylene sulfide film, an aramid film, and the like. Among them, a polyimide film is used from the viewpoint of heat resistance, dimensional stability, mechanical properties, and the like. preferable. As this polyimide film, the heat-fusible polyimide film whose surface is thermoplastic is preferable from the viewpoint of adhesion to the metal foil with a functional film of the present invention.

  The thermoplastic polyimide on the polyimide film surface is selected from, for example, 1,3-bis (3-aminophenoxy) benzene, 4,4′-bis (3-aminophenoxy) biphenyl, and 3,3′-diaminobenzophenone. At least one diamine, 3,3 ′, 4,4′-diphenyl ether tetracarboxylic dianhydride, 3,3 ′, 4,4′-benzophenone tetracarboxylic dianhydride, pyromellitic dianhydride And a polyimide synthesized from at least one tetracarboxylic dianhydride selected from 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride.

  The metal-clad laminate of the present invention may have a structure in which the above-described metal foil with a functional film of the present invention is laminated on one side of the insulating organic substrate via the functional film. The metal foil with functional film may be laminated on both surfaces of the insulating organic base material via the functional film.

  Lamination of the insulating organic base material and the metal foil with a functional film is performed such that the bonding surface of the insulating organic base material faces the functional film of the metal foil with a functional film, for example, the insulating organic base material is In the case of polyimide, a single-sided metal-clad laminate or a double-sided metal-clad laminate can be produced by bonding at a temperature of 180 to 350 ° C. under pressure.

  1 and 2 are cross-sectional views of different examples of the flexible metal-clad laminate of the present invention. FIG. 1 shows an example of a single-sided metal-clad laminate, and FIG. An example is shown.

  In FIG. 1, a single-sided metal-clad laminate 10 shows a structure in which a functional film 2 is interposed between a metal foil 1 and an insulating organic substrate 3. On the other hand, in FIG. 2, the double-sided metal-clad laminate 20 shows a structure in which metal foils 11a and 11b are laminated on both surfaces of an insulating organic base material 13 via functional films 12a and 12b, respectively.

  In addition, in the metal-clad laminate of the present invention, in addition to the structure in which the above-described metal foil with a functional film of the present invention is laminated via the functional film, the above-described functional film is placed on the organic substrate surface side. It may have a structure in which the formed organic base material with a functional film is laminated via the functional film, and the same effect is obtained.

  The flexible metal-clad laminate of the present invention having such a structure can be used as a material for producing an electronic component mounting module shown below.

[Electronic component mounting module and its manufacturing method]
The electronic component mounting module of the present invention is characterized in that an electronic component is mounted using the above-described flexible metal-clad laminate of the present invention and an anisotropic conductive film.

  In addition, the manufacturing method of the electronic component mounting module according to the present invention includes: (a) a step of etching the metal foil of the above-described flexible metal-clad laminate to form a circuit pattern and producing a flexible wiring board; (b) A step of temporarily crimping an anisotropic conductive film on the circuit pattern of the flexible wiring board; (c) placing an electronic component on the anisotropic conductive film; And (d) a step of curing and subjecting the matrix resin of the anisotropic conductive film to a final press-bonding by a heating and pressurizing process.

  Next, FIG. 3 is a process diagram showing an example of a method for manufacturing an electronic component mounting module according to the present invention. The manufacturing method will be described with reference to FIG. FIG. 3 shows an example in which a single-sided metal-clad laminate is used as the flexible metal-clad laminate.

(Step (a))
In the method for manufacturing an electronic component mounting module according to the present invention, the step (a) includes the above-described metal-clad laminate [10] in which the functional film 2 is interposed between the metal foil 1 and the insulating organic substrate 3 [ (A) Refer to FIG.] The metal foil 1 is etched to form a circuit pattern 1a to produce a flexible wiring board 30 [refer to FIG. (B)].

  There is no restriction | limiting in particular about the etching processing method of the metal foil 1 in the said (a) process, A conventionally well-known method is employable. That is, a predetermined resist pattern is first formed by photolithography, and then the metal foil 1 is etched using the resist pattern as a mask to form a predetermined circuit pattern 1a.

((B) Process)
This (b) process is a process of temporarily pressure-bonding the anisotropic conductive film 4 on the circuit pattern 1a of the flexible wiring board 30 produced in the (a) process [see (c) figure].

<Anisotropic conductive film>
There is no restriction | limiting in particular in the anisotropic conductive film 4 used at the said (b) process, Arbitrary things are suitably selected from the well-known anisotropic conductive films currently used when mounting an electronic component on a flexible wiring board. Can be used.

  The anisotropic conductive film 4 is a film adhesive having a thickness of about 10 to 50 μm in which conductive particles 5 having a diameter of about 3 to 10 μm are uniformly dispersed in an adhesive matrix resin 6. Examples of the conductive particles 5 include nickel particles, gold-plated particles, and nickel / gold-plated particles on a plastic core, and are selected according to the type of adherend. As the matrix resin 6 of the adhesive, an epoxy resin having a low connection resistance and excellent in heat resistance and connection reliability is currently in the mainstream.

  The particle size distribution of the conductive particles 5 to be applied is preferably as sharp as possible due to the mechanism of anisotropy, and the material is, for example, nickel particles for connection to a printed circuit board (PWB), flexible printed wiring board (FPC) and glass. For connection to the substrate electrode, it is advantageous to use conductive particles of nickel / gold plated on the plastic core.

  The core material used for the conductive particles is flat when plastic is connected and does not damage the thin film electrode, can be connected with a large contact area, and due to the adhesion to the electrode due to the deformation recovery force of the conductive particles, It is better than hard materials such as silica because high connection reliability is obtained.

(Step (c))
In this step (c), the electronic component 7 is placed on the anisotropic conductive film 4 so that the connection terminal 8 of the electronic component 7 can be connected to a predetermined circuit of the circuit pattern 1a in the flexible wiring board. This is a process of positioning [see FIG.

((D) step)
In the step (d), after the alignment in the step (c), a heat and pressure treatment is performed at about 150 to 180 ° C. under a pressure of about 2 to 3 MPa to cure the matrix resin 6 of the anisotropic conductive film 4. It is the process of making it carry out this pressure bonding.

  Since the adhesive matrix resin 6 melts and flows during the heating and pressing process, the conductive particles 5 are trapped between the pressurized upper and lower connection terminals 8 and the circuit pattern 1a, and the matrix resin is connected to the connection terminals. Fill the space between the circuit patterns while spreading. In addition, since the matrix resin is usually thermosetting, the curing reaction starts immediately after melting and flowing, and the connection process is completed in a connection time for thickening and solidifying and heating and pressurizing for about 5 to 10 seconds. [See (e) Figure].

  The connection body is bonded by a cured adhesive, and the electrodes to be connected are electrically connected through conductive particles, and insulation is maintained because an insulating adhesive is filled between adjacent electrodes. .

  In this way, the electronic component mounting module 40 with good quality can be efficiently manufactured.

EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited at all by these examples.
In addition, evaluation of the adhesiveness of an anisotropic conductive film (ACF) was performed by the method shown below.

(1) Production of a copper-clad laminate A double belt press device (set temperature 330 ° C.) is formed by superimposing a copper foil and a polyimide film having heat-fusibility (“UPILEX VT” manufactured by Ube Industries, Ltd., thickness 15 μm). And pressurizing time 2 minutes) to obtain a copper clad laminate.

(2) Production of Film Substrate for Evaluation The copper-clad laminate obtained in (1) above was immersed in a 35% by mass ferric chloride aqueous solution at 30 ° C. for 30 minutes, and the copper foil was removed by etching and washed with water. Next, it was immersed in “FLICKER-MH” manufactured by Nippon Chemical Industry Co., Ltd. for 20 minutes at 30 ° C., rinsed with a 3 mass% hydrochloric acid aqueous solution, and then washed with water to obtain a film substrate for evaluation.

(3) Production of pseudo ACF 22.5 g of epoxy resin (“Epicoat 1009” manufactured by Japan Epoxy Resin Co., Ltd.) was dissolved in a mixed solvent of 13.75 g of toluene and 13.75 g of methyl ethyl ketone, and a latent curing agent (Asahi Kasei) 22.5 g of “HX3941HP” manufactured by Co., Ltd. and 0.45 g of a coupling agent (“KBM-403” manufactured by Shin-Etsu Silicone Co., Ltd.) were added to obtain a pseudo ACF precursor solution.

  A pseudo ACF precursor solution was cast on a release film (“Film Binner” manufactured by Fujimori Kogyo Co., Ltd.) so as to have a liquid film thickness of 75 μm, and dried in a drying furnace at 80 ° C. for 9 minutes. The obtained coating film was peeled off from the release film to obtain a pseudo ACF.

(4) Preparation of pseudo ACF pressure-bonded sample On the mat surface of the reinforcing copper foil ("BHY-13H-T" manufactured by Nikko Metal Co., Ltd., thickness 18 μm), the pseudo ACF obtained in the above (3) is applied. Furthermore, a film substrate for evaluation was superimposed thereon, and pressure-bonded by a press machine at 170 ° C., 9 MPa, and 5 minutes to obtain a pseudo ACF pressure-bonded sample.

(5) Measurement of pseudo ACF adhesive strength The pseudo ACF pressure-bonded sample obtained in (4) above was measured in each state after (a) initial stage, (b) reflow, and (c) PCT. Here, (a) the initial state is the state immediately after the pseudo ACF pressure bonding, and (b) the state after the reflow is put in a drying furnace having a temperature profile of 250 ° C. at maximum, taken out and returned to room temperature. (C) After PCT, (b) refers to the state after the reflowed sample is further put into a 105 ° C./100% RH pressure cooker tester for 12 hours, taken out and returned to room temperature.

  A pseudo ACF pressure-bonded sample was cut into a width of 2 mm, set in a tensile tester equipped with a rotating drum type support, and the film substrate was sandwiched between chucks and peeled in a 90 ° direction to measure the pseudo ACF adhesive strength.

Preparation Example 1 Preparation of Condensate 1 Solution Tetraisopropoxytitanium (17.41 g) was dissolved in ethylene glycol mono-t-butyl ether (42.6 g). A solution prepared by mixing water (1.2 g), 63 mass% concentrated nitric acid (2.8 g) and ethylene glycol mono-t-butyl ether (6.0 g) was added dropwise thereto, and a condensation reaction was performed at 30 ° C. for 4 hours. The condensate 1 solution was prepared.

Preparation Example 2 Preparation of Condensate 2 Solution Tetraisopropoxytitanium (7.31 g) and γ-phenylaminopropyltrimethoxysilane (3.9 g) were dissolved in ethylene glycol mono-t-butyl ether (50.8 g). A solution obtained by mixing water (0.8 g) and ethylene glycol mono-t-butyl ether (7.3 g) was added dropwise thereto, and a condensation reaction was performed at 30 ° C. for 4 hours to prepare a condensate 2 solution.

Example 1 No anchor effect Ethylene glycol mono-t-butyl ether (12 g) was mixed with the condensate 2 solution (2 g) to prepare a coating solution. The obtained coating solution was applied to a copper foil (“BHYA-13H-HA” manufactured by Nikko Metal Co., Ltd., 18 μm thickness) with a Mayer bar (No. 5), and dried in an oven at 120 ° C. for 1.5 minutes. Using the obtained copper foil, the adhesion was evaluated according to “ACF adhesion evaluation”. The results are shown in Table 1.

Example 2 Has anchoring effect Condensate 1 solution (0.6 g), dispersion (1.4 g) in which 200 nm silica fine particles are dispersed in methanol (25% by mass) and ethylene glycol mono-t-butyl ether (8.0 g) ) To prepare a coating solution. The obtained coating solution was applied to a copper foil (“BHYA-13H-HA” manufactured by Nikko Metal Co., Ltd., 18 μm thickness) with a Mayer bar (No. 7), and dried in an oven at 120 ° C. for 1.5 minutes. Using the obtained copper foil, the adhesion was evaluated according to “ACF adhesion evaluation”. The results are shown in Table 1.

Example 3 Has anchor effect Condensate 2 solution (0.6 g), dispersion (1.4 g) in which 200 nm silica fine particles were dispersed in methanol (25% by mass) and ethylene glycol mono-t-butyl ether (8.0 g) ) To prepare a coating solution. The obtained coating solution was applied to a copper foil (“BHYA-13H-HA” manufactured by Nikko Metal Co., Ltd., 18 μm thickness) with a Mayer bar (No. 7), and dried in an oven at 120 ° C. for 1.5 minutes. Using the obtained copper foil, the adhesion was evaluated according to “ACF adhesion evaluation”. The results are shown in Table 1.

Comparative Example 1
Adhesion was evaluated according to “Evaluation of ACF Adhesion” using a copper foil (“BHYA-13H-HA” manufactured by Nikko Metal Co., Ltd., 18 μm thickness) not subjected to surface treatment. The results are shown in Table 1.

  The metal foil with a functional film of the present invention can provide a flexible metal-clad laminate in which a metal foil is laminated with good adhesion on at least one surface of an insulating organic substrate such as a heat-fusible polyimide film, Using this metal-clad laminate, an electronic component mounting module with good quality can be provided.

It is sectional drawing which shows one example of the flexible metal clad laminated board of this invention. It is sectional drawing which shows the example from which the flexible metal-clad laminated board of this invention differs. It is process drawing which shows an example of the manufacturing method of the electronic component mounting module of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 11a, 11b Metal foil 1a Circuit pattern 2, 12a, 12b Functional film 3, 13 Insulating organic base material 4 Anisotropic conductive film 5 Conductive particle 6 Matrix resin 7 Electronic component 8 Connection terminal 10 Single-sided metal-clad laminate 20 Both sides Metal-clad laminate 30 Flexible wiring board 40 Electronic component mounting module

Claims (8)

A metal foil with a functional film having an insulating functional film on one side of the conductive metal foil, wherein the insulating functional film has the general formula (I)
R ¹ _n M (OR ² ) _m−n (I)
Wherein R ¹ is a non-hydrolyzable group, R ² is an alkyl group having 1 to 6 carbon atoms, M is a metal atom selected from silicon, titanium, zirconium and aluminum, and m is a metal atom The valence of M is 3 or 4, and n is an integer of 0 to 2 when m is 4, an integer of 0 to 1 when m is 3, and each R when there are a plurality of R ^{1 1} may be different even identical to each other, if the OR ² there are a plurality, each OR ² may be different even identical to each other.)
A functional film formed by using a coating liquid containing a condensate having a main skeleton of a MO repeating unit obtained by hydrolysis-condensation of a metal alkoxide compound represented by With metal foil.   The metal foil with a functional film according to claim 1, wherein the metal alkoxide has two or more metal atoms M.   The metal foil with a functional film according to claim 1 or 2, wherein the coating liquid further contains insulating particles.   The metal foil with a functional film according to any one of claims 1 to 3, wherein the conductive metal foil is a copper foil.   A flexible metal-clad laminate, wherein the functional film-attached metal foil according to any one of claims 1 to 4 is laminated on at least one surface of an insulating organic substrate via the functional film. Board.   The flexible metal-clad laminate according to claim 5, wherein the insulating organic substrate is a heat-fusible polyimide film.   An electronic component mounting module comprising an electronic component mounted using the flexible metal-clad laminate according to claim 5 or 6 and an anisotropic conductive film.   (A) a step of etching the metal foil of the flexible metal-clad laminate according to claim 5 or 6 to form a circuit pattern to produce a flexible wiring board; (b) on the circuit pattern of the flexible wiring board; (C) placing an electronic component on the anisotropic conductive film so that a connection terminal of the electronic component and a predetermined circuit of a circuit pattern on the flexible wiring board can be connected to each other. And (d) a step of curing the matrix resin of the anisotropic conductive film and subjecting it to a final press-bonding by a heat and pressure treatment, and a method of manufacturing an electronic component mounting module.

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