JP2002314240A - Method for mounting electronic component to flexible printed wiring board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for mounting electronic components to a flexible printed wiring board (FPC) which can easily stick or separate the FPC to or from a fixing plate when the electronic components are mounted to the flexible printed wiring board, and can fix the FPC firmly. SOLUTION: In a method for mounting electronic components to a flexible printed wiring board, when the electronic components are mounted to a surface of the flexible printed wiring board, after the flexible printed wiring board is fixed to a surface of an adhesive layer of a fixing plate having the adhesive layer on the surface, the electronic components are mounted to the surface of the flexible printed wiring board. In the fixing plate having the adhesive layer on the surface, the adhesive layer of an adhesive sheet having at least on one face thereof may be attached to one face of the fixing plate so that the adhesive layer comes to a surface side which is a reverse side to a fixing plate side. Further, preferably, the adhesive layer of the fixing plate is constituted by adhesives having easily separating properties.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flexible printed circuit board (hereinafter sometimes abbreviated as "FPC").
The present invention relates to a method of mounting an electronic component on a flexible printed wiring board, which can easily fix an FPC to a fixing plate when mounting the electronic component on the flexible printed wiring board, and can automatically mount the electronic component accurately.

[0002]

2. Description of the Related Art Conventionally, mounting of various electronic components (for example, IC and capacitor) at the time of manufacturing an electronic circuit board has
It can be performed automatically using a mounting machine [for example, Panazard (manufactured by Matsushita Electric Industrial Co., Ltd.) or the like] on a rigid substrate (glass plate, epoxy plate, or the like). In the method,
When the electronic components are mounted, the rigid board is required to have a high positional accuracy. Therefore, the rigid board is usually transported in such a manner that the rigid board is sandwiched by transport rails so as not to move.

On the other hand, in recent years, electronic devices have been reduced in size and weight, and therefore, electronic components have been directly mounted on the surface of a flexible printed wiring board (FPC) (surface mounting).
May be done. In case of FPC, FPC itself (substrate)
Because of its lack of rigidity, it is not fixed firmly even if it is sandwiched between transport rails, resulting in low positional accuracy. Therefore, for example, FIG.
The electronic components are mounted by fixing the FPC to a fixing plate by the method shown in FIG. FIG. 4 is a schematic view showing a typical example of a conventional FPC fixing method. In FIG. 4, 4 is an FPC, 6 is a motherboard (fixing plate), 71 is a guide pin for fixing the motherboard, 72 is a guide pin for positioning the FPC, 8 is a fixing base, and 9 is an adhesive tape. FIG.
In the method indicated by, the FPC 4 is placed on the surface of the motherboard 6 (such as an aluminum plate) with the FPC alignment guide pins 72 aligned with the holes provided in the FPC 4, and the adhesive tape 9 (polyimide film or fluororesin-based After attaching the FPC 4 to the motherboard 6 by using a conventional adhesive tape such as an adhesive tape having a film as a base material and an adhesive layer formed on one surface thereof on one side thereof, from about 2 to 4 places from above the FPC 4 and fixing the FPC 4 , The motherboard 6
Guide pins for fixing the motherboard to the fixing stand 8 for transportation.
The electronic components are mounted by fixing the 71 in accordance with the perforations provided in the motherboard 6 and sandwiching the 71 with a transport rail.

[0004]

However, in the conventional electronic component mounting process as shown in FIG.
When fixing the FPC to the fixing plate, only two or four ends of the FPC are fixed with adhesive tape, so that the fixing strength of the FPC is low and a gap is generated between the FPC and the fixing plate. Therefore, when mounting electronic components on FPC,
Positional accuracy of C, particularly in the vertical direction, is low. Further, since a thin adhesive tape is stuck to one FPC at several places, it takes a lot of time to attach and detach the FPC, and the workability is low.

Accordingly, an object of the present invention is to provide a method for mounting an electronic component on a flexible printed wiring board (FPC).
An object of the present invention is to provide a method for mounting an electronic component on a flexible printed wiring board, which allows easy attachment and detachment of an FPC to and from a fixed plate and can be firmly fixed.
Another object of the present invention is to mount and remove an FPC with respect to a fixing plate with excellent workability when mounting an electronic component on the FPC, and to mount the electronic component on the FPC with high accuracy. It is an object of the present invention to provide a method of mounting an electronic component on a flexible printed wiring board which can perform the method.

[0006]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to achieve the above-mentioned object, and as a result, when mounting electronic components on the surface of a flexible printed wiring board (FPC), the surface of the fixing plate has adhesiveness. When a layer is provided and the FPC is fixed to the surface of the adhesive layer of the fixing plate, the fixing of the FPC to the fixing plate is easy and the FPC can be fixed firmly.
Therefore, it has been found that the FPC does not shift in position, and that the electronic component can be automatically mounted on the FPC with high accuracy, and the present invention has been completed.

That is, according to the present invention, when mounting an electronic component on the surface of a flexible printed wiring board, the flexible printed wiring board is fixed on the surface of the adhesive layer of the fixing plate having an adhesive layer on the surface, and A method for mounting an electronic component on a flexible printed wiring board, wherein the electronic component is mounted on a surface of the printed wiring board.

In the present invention, the fixing plate having the adhesive layer on the surface is such that the adhesive layer of the adhesive sheet having the adhesive layer on at least one surface is on the surface side opposite to the fixing plate side. The one attached to one surface of the fixing plate can be suitably used. Further, it is preferable that the adhesive layer of the fixing plate to which the flexible printed wiring board is adhered is made of an adhesive having easy peelability.

[0009]

Embodiments of the present invention will be described below with reference to the drawings as necessary. FIG. 1 is a schematic view showing a method for mounting an electronic component on an FPC according to the present invention. Specifically, FIG. 1 is a schematic diagram showing a state in which the FPC is attached to a fixing plate, FIG. 1A is a diagram viewed from the upper side, and FIG. 1B is a diagram viewed from the side. It is. In FIG. 1, 4 is an FPC, 5 is a double-sided adhesive sheet with a base material, 51 is an adhesive layer of the double-sided adhesive sheet 5, 6 is a fixing plate, 71 is a guide pin for fixing a motherboard, 72 is a guide pin for positioning an FPC, 71a is a perforation for inserting the guide pin 71 for fixing the motherboard, 72a is a perforation for inserting the guide pin 72 for positioning the FPC, and 8 is a fixing stand for transport. In FIG. 1, the fixing plate 6
The double-sided adhesive sheet 5 is adhered to the entire surface or almost the entire surface on one side of the above, and the FPC 4 is attached to a predetermined portion on the adhesive layer 51 of the double-sided adhesive sheet 5. More specifically, the double-sided adhesive sheet 5 is attached to one surface of the fixing plate 6, and the FPC positioning guide pins 72 and the perforated holes are formed at predetermined positions on the other adhesive layer 51 of the double-sided adhesive sheet 5. 72
After affixing FPC4 using a, the FPC4
The fixing plate 6 to which is adhered is fixed to the fixing stand 8 for conveyance by using the guide pins 71 for fixing the motherboard and the perforations 71a. The perforations 71a for passing the guide pins 71 for fixing the motherboard and the perforations 72a for passing the guide pins 72 for aligning the FPC are formed by, for example, punching after the double-sided adhesive sheet 5 is attached to the fixing plate 6. can do.

As described above, according to the present invention, since the FPC is placed on a predetermined portion of the surface of the adhesive layer of the fixing plate having the adhesive layer on the surface and fixed by sticking, the FPC can be easily attached to the fixing plate. Can be fixed. Also, when removing the FPC on which the electronic component is mounted after mounting the electronic component, the FPC on which the electronic component is mounted may be simply removed from the fixing plate having the adhesive layer on the surface, and the adhesive tape may be removed. No need to peel off. Therefore, with excellent workability, FPC
Can be fixed to the fixing plate, and the FPC can be removed from the fixing plate.

Further, since the entire lower surface of the FPC is fixed to the fixing plate via the adhesive layer, the FPC can be firmly fixed to the fixing plate. Therefore, little or no gap is generated between the FPC and the fixing plate (the adhesive layer on the surface of the fixing plate). Therefore, when the electronic component is fixed to the FPC, no displacement or the like of the FPC occurs, so that the electronic component can be mounted on the FPC with high positional accuracy.

[Fixed Plate Having Adhesive Layer on Surface] The fixed plate 6 having the adhesive layer 51 on the surface is not particularly limited as long as the plate has an adhesive layer on the surface. As the fixing plate 6, a plate that is hard and can ensure planarity, for example, an aluminum plate, a glass plate, a plate made of an epoxy resin, or the like can be used. It can be appropriately selected according to a mounting device (particularly, an automatic mounting device) for mounting electronic components on the electronic component.

A fixing plate 6 having an adhesive layer 51 on its surface
For example, a fixed plate having an adhesive layer formed on the surface thereof by applying an adhesive may be used, but the surface of the adhesive layer in an adhesive sheet (such as an adhesive tape) is opposite to the fixed plate. A fixing plate to which an adhesive sheet is attached so as to be on the side can be suitably used.

[Adhesive Sheet] As an adhesive sheet for forming an adhesive layer on the surface of the fixing plate, a single-sided adhesive sheet as shown in FIG. 2 or a double-sided adhesive sheet as shown in FIG. Sheets can be used. FIG. 2 is a sectional view showing an example of the adhesive sheet according to the present invention, and FIG. 3 is a sectional view showing another example of the adhesive sheet according to the present invention.

In FIG. 2, reference numeral 1 denotes an adhesive sheet for fixing a flexible printed wiring board (hereinafter sometimes referred to as an “adhesive sheet for fixing an FPC” or simply an “adhesive sheet”);
2 is an adhesive layer and 3 is a substrate. In the example of FIG.
The fixing adhesive sheet 1 has a structure in which an adhesive layer 2 is laminated on one surface (one surface) of a substrate 3. In FIG. 3, reference numeral 11 denotes an FPC fixing adhesive sheet, 21 denotes an adhesive layer, and 31 denotes a base material. In the example of FIG. 3, the FPC fixing adhesive sheet 11 has a structure in which an adhesive layer 21 is laminated on both surfaces of a base material 31. Thus, in the present invention, F
As the PC fixing adhesive sheet (1, 11), a sheet formed by laminating an adhesive layer on one side and / or both sides of a base material can be used.

[Substrate] In the adhesive sheet (1, 11),
The substrate (3, 31) is not particularly limited, and includes, for example, cellophane, polytetrafluoroethylene, polyethylene,
Plastic film made of plastic such as polyester such as polyethylene terephthalate; natural rubber,
Rubber sheet made of butyl rubber, etc .; foam made of polyurethane, polychloroprene rubber, etc .; aluminum foil,
A metal foil such as a copper foil may be used, but a porous substrate made of a fibrous substance such as paper or nonwoven fabric can be suitably used.

In the electronic component mounting process, the FPC is usually exposed to a very high temperature for a short time to melt the solder. For example, heating by infrared (I
In R heating), there are various heating conditions, but a typical example is a heating condition in which the peak temperature at which the maximum temperature is reached is about 260 ° C. and the holding time of the peak temperature is about 20 seconds. In the case of an adhesive sheet such as an adhesive tape that has undergone a heating step at such a very high temperature, the moisture or the like contained in the adhesive rapidly expands (gasifies) during IR heating, and the like. From adhesive sheet to FPC and / or
Alternatively, the fixing plate may be peeled off. However, when a porous base material is used as the base material of the adhesive sheet for fixing an FPC, even if the porous base material is exposed to a high temperature in a heating step (particularly, an IR heating step), a decrease in adhesiveness is suppressed or prevented, and a high adhesiveness is obtained. Can be held. That is, the state where the FPC and / or the fixing plate is adhered to the adhesive sheet is maintained even after the heating step in which the temperature becomes extremely high. More specifically, in a heating step for melting solder or the like, even if the moisture or the like contained in the adhesive rapidly expands (vaporizes), if the substrate is a porous substrate, the adhesive is The gas component vaporized in the functional layer can be released to the outside through the porous substrate, and the FPC can be suppressed or prevented from peeling off from the pressure-sensitive adhesive layer. Therefore, even after the heating step, the FPC is not displaced, and the electronic component can be mounted on the FPC with high positional accuracy. That is, when a porous substrate is used as the substrate, the positional accuracy of mounting the electronic component on the FPC can be significantly improved.

The porous substrate is not particularly limited as long as it is a porous substrate, in addition to various characteristics such as the shape of the pore, its diameter (average cell diameter), and density, as well as the material of the substrate. The porous substrate preferably has a form of open cells in the adhesive layer in order to release a vaporized gas component to the outside. That is, when the porous substrate has the form of open cells, the gas component (such as water vapor) vaporized in the adhesive layer can be released to the outside from the open end of the porous substrate.

In the present invention, examples of the porous substrate, especially a porous substrate made of a fibrous substance, include porous paper materials (for example, kraft paper, crepe paper, Japanese paper, clay-coated paper, woodfree paper, glassine). Paper, clupak paper, etc.),
Porous cloth material (for example, aramid fiber, rayon fiber, acetate fiber, polyester fiber, polyvinyl alcohol fiber, polyamide fiber, polyolefin fiber, fluorine fiber, stainless fiber, asbestos, glass cloth, glass fiber, manila hemp, pulp, etc. Nonwoven fabrics and woven fabrics of natural fibers). In the porous substrate made of a fibrous substance, the fibrous substance may be used alone or in combination of two or more. Further, the porous substrates can be used alone or in combination of two or more.

In the present invention, as the porous substrate, Japanese paper or nonwoven fabric is preferable from the viewpoints of anchoring properties of the adhesive, permeability of gas components such as water vapor, heat resistance, and the like. As the porous substrate, aramid fibers can be suitably used from the viewpoint of heat resistance. In addition, Japanese paper and clay-coated paper
Since it is inexpensive and has heat resistance, it is useful as a porous substrate.

Further, in the present invention, it is preferable that the porous substrate is made of only a fibrous substance (fiber component) without adding a substance such as a binder. In particular, a porous substrate that is neutral or almost neutral and contains rayon fibers as a fiber component is preferable. As the porous base material containing such rayon fibers, those having a high content ratio of rayon fibers are preferable, and the content ratio of the rayon fibers is, for example, 30 to all fiber components.
It can be selected from a range of at least 50% by weight, preferably at least 50% by weight.

The thickness of the substrate (particularly, the porous substrate) is not particularly limited and can be appropriately selected depending on the application.
For example, 25 to 200 μm (preferably 50 to 150 μm)
m).

When paper or nonwoven fabric is used as the porous substrate, its basis weight is not particularly limited.
It may be about 1 to 300 g / m ² .

[Adhesive Layer] As the adhesive (pressure-sensitive adhesive) constituting the adhesive layer (2, 21), a common or known adhesive can be used in an adhesive sheet such as an adhesive tape. In addition to a system-based pressure-sensitive adhesive and a silicone-based pressure-sensitive adhesive, a rubber-based pressure-sensitive adhesive in which an additive such as a tackifying resin is blended with an elastomer is exemplified. As the pressure-sensitive adhesive, an acrylic pressure-sensitive adhesive or a silicone pressure-sensitive adhesive can be suitably used. An acrylic pressure-sensitive adhesive is preferable from the viewpoint of heat resistance and easy peeling of the FPC after mounting. When particularly high heat resistance is required, a silicone-based pressure-sensitive adhesive is preferred. The adhesives can be used alone or in combination of two or more.

The acrylic pressure-sensitive adhesive contains a (meth) acrylic acid alkyl ester-based copolymer containing a (meth) acrylic acid alkyl ester as a main monomer component as a base polymer. More specifically, (meta)
Acrylic polymer comprising a polymer (including a copolymer) of an alkyl acrylate or a copolymer of the alkyl (meth) acrylate and another monoethylenically unsaturated monomer (copolymerizable monomer) Is used as a base polymer, and additives such as a cross-linking agent (such as a cross-linking agent) and a tackifying resin are added to the base polymer as needed.

As the (meth) acrylic acid alkyl ester, generally, an alkyl (meth) acrylate having an alkyl group having about 4 to 14 carbon atoms can be suitably used. Specifically, as the alkyl (meth) acrylate, butyl (meth) acrylate, isooctyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isononyl (meth) acrylate, lauryl (meth) acrylate, and the like are preferable. Used. The alkyl (meth) acrylates can be used alone or in combination of two or more.

These alkyl (meth) acrylates are used as main monomer components. Specifically, in the acrylic polymer, the proportion of the alkyl (meth) acrylate can be selected, for example, from the range of 50% by weight or more (50 to 100% by weight) based on the total amount of the monomer components. The proportion of the alkyl (meth) acrylate is preferably 80% by weight or more, more preferably 90% by weight or more, and particularly preferably 97% by weight or more.
Most preferably, it is not less than% by weight.

As a monomer component in the acrylic polymer, when a functional group-containing copolymerizable monomer copolymerizable with the alkyl (meth) acrylate is used together with the alkyl (meth) acrylate, the FPC
And the like, the adhesiveness to an adherend can be improved. Examples of the functional group-containing copolymerizable monomer include, for example, a carboxyl group-containing copolymerizable monomer, a nitrogen atom-containing copolymerizable monomer, a hydroxyl group-containing copolymerizable monomer, an epoxy group-containing copolymerizable monomer, and a mercapto group-containing copolymerizable monomer. And isocyanate group-containing copolymerizable monomers. More specifically, the functional group-containing copolymerizable monomer includes, for example, a carboxyl group-containing copolymerizable monomer such as acrylic acid, methacrylic acid, itaconic acid, maleic anhydride, crotonic acid, maleic acid, and fumaric acid; (Meth) acrylamide, N-vinylpyrrolidone, (meth)
Acryloyl morpholine, (meth) acrylonitrile,
Nitrogen atom-containing copolymerizable monomers such as aminoethyl (meth) acrylate, cyclohexylmaleimide, and isopropylmaleimide; hydroxymethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate A hydroxyl-containing copolymerizable monomer such as glycerin dimethacrylate;
An epoxy group-containing copolymerizable monomer such as glycidyl (meth) acrylate; an isocyanate group-containing copolymerizable monomer such as 2-methacryloyloxyethyl isocyanate is included, and a mercapto group at the terminal of a chain transfer agent is introduced as a functional group. It is also possible. Among these functional group-containing copolymerizable monomers, a carboxyl group-containing monomer is preferred in terms of reactivity and versatility, and acrylic acid and methacrylic acid are more preferred.

The proportion of the functional group-containing copolymerizable monomer is 10% by weight or less (for example, 0 to
10% by weight), preferably about 3% by weight or less (0 to 3% by weight).

The acrylic polymer may contain other copolymerizable monomers as monomer components, if necessary, in addition to the main monomer and the functional group-containing copolymerizable monomer. Such a copolymerizable monomer has, for example, an alkyl group such as methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, and isopropyl (meth) acrylate having 1 carbon atom. To 3 alkyl (meth) acrylates; alkyl (meth) acrylates having 15 to 20 carbon atoms in the alkyl group such as stearyl (meth) acrylate; vinyl esters such as vinyl acetate; styrenes such as styrene Monomers; α-olefin monomers such as ethylene and propylene are included.

In the acrylic polymer, the monomer component other than the alkyl (meth) acrylate as the main monomer component may be selected from a range of less than 50% by weight based on the total amount of the monomer component, but is preferably used. It is desirable to have less than 20% by weight, more preferably less than 10% by weight, especially less than 3% by weight.

In the present invention, a known crosslinking agent such as an isocyanate-based compound or an epoxy-based compound is added as a cross-linking agent, or when photopolymerization is performed, in order to improve the holding properties of the pressure-sensitive adhesive. It is useful to add a polyfunctional (meth) acrylate. The crosslinking agents can be used alone or in combination of two or more. In the crosslinking agent, as the isocyanate-based compound, for example, a polyfunctional isocyanate compound having two or more isocyanate groups, for example, diphenylmethane diisocyanate, 2,4-tolylene diisocyanate,
Aromatic diisocyanates such as 2,6-tolylene diisocyanate, phenylene diisocyanate, 1,5-naphthylene diisocyanate, xylylene diisocyanate and toluylene diisocyanate; hexamethylene diisocyanate, isophorone diisocyanate, 4,4 '
-In addition to aliphatic or cycloaliphatic diisocyanates such as dicyclohexylmethane diisocyanate, diphenylmethane diisocyanate dimers, reaction products of trimethylolpropane and tolylene diisocyanate, reaction products of trimethylolpropane and hexamethylene diisocyanate, polyethers Polyisocyanate, polyester polyisocyanate and the like can be mentioned. Further, as the epoxy compound, a polyfunctional epoxy compound having two or more epoxy groups, for example, diglycidyl aniline,
Glycerin diglycidyl ether and the like can be mentioned.

Examples of the polyfunctional (meth) acrylate as a cross-linking agent used in the case of performing photopolymerization include, for example, trimethylolpropane tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, and ethylene glycol diacrylate. (Meth) acrylate,
Examples include 1,6-hexanediol di (meth) acrylate.

The acrylic polymer can be synthesized from a mixture of the above-mentioned monomer components by a general polymerization method, for example, an emulsion polymerization method or a solution polymerization, by general batch polymerization, continuous drop polymerization, divided drop polymerization, or the like. . In the polymerization, a commonly used or known polymerization initiator may be used. In the emulsion polymerization, a commonly used or known emulsifier may be used. The polymerization temperature is, for example, 3
The range is from 0 to 80 ° C.

When a particularly high heat resistance (high heat resistance) is required as the pressure-sensitive adhesive, a polymer obtained by irradiation with ultraviolet rays is preferable. In addition, various known additives such as tackifiers, plasticizers, softeners, fillers, colorants (eg, pigments and dyes), antioxidants, antioxidants, and the like may be added to the adhesive as optional components. Can be added. Examples of the tackifying resin include petroleum resins such as aliphatic petroleum resins, aromatic petroleum resins, and alicyclic petroleum resins obtained by hydrogenating aromatic petroleum resins (alicyclic saturated hydrocarbon resins); , Hydrogenated rosin esters, etc.), terpene resins (terpene resins,
Aromatic modified terpene resins, hydrogenated terpene resins, terpene phenol resins, etc.), styrene resins, and cumarone indene resins.

The adhesive layer (2, 21) can be formed by applying the above-mentioned adhesive on at least one surface of a porous substrate.

The thickness of the adhesive layer (2, 21) is not particularly limited, and can be selected, for example, from a range of about 10 to 200 μm, and preferably about 20 to 100 μm.

[Adhesive Sheet] The adhesive sheet of the present invention may be, for example, a pressure-sensitive adhesive (pressure-sensitive adhesive) such as an acrylic pressure-sensitive adhesive on at least one surface (one or both surfaces) of a substrate, especially a porous substrate. ) Is applied, and if necessary, the adhesive composition is cross-linked by heating or the like, or is polymerized by irradiation with ultraviolet light to form an adhesive layer on at least one surface of a substrate (particularly a porous substrate). Can be formed and manufactured. Further, if necessary, a release liner may be coated on the adhesive layer. Therefore, the adhesive sheet (adhesive sheet) of the present invention may be a double-sided adhesive sheet having an adhesive layer on both sides of a substrate such as a porous substrate, and an adhesive sheet on one side of a substrate such as a porous substrate. It may be a single-sided adhesive sheet having a functional layer.

The adhesive sheet of the present invention is preferably a double-sided adhesive sheet. In the case of a double-sided adhesive sheet, the adhesive in each of the adhesive layers laminated on both sides of the porous substrate may be different adhesives or the same adhesive.

By using such an adhesive sheet, a fixing plate having an adhesive layer on the surface can be manufactured. In FIG. 1, a double-sided adhesive sheet 5 with a porous substrate is provided between the fixing plate 6 and the FPC 4,
The fixing plate 6 and the FPC 4 are adhered. That is, the fixing plate 6 and the FPC 4 are bonded via the double-sided adhesive sheet 5. In particular, in FIG. 1, the double-sided adhesive sheet 5 with a base material made of a porous base material is adhered to the entire surface of one surface of the fixing plate 6. , A portion where the FPC is installed and its peripheral portion).

In the present invention, the adhesive sheet may be a single-sided adhesive sheet with a substrate (adhesive tape), particularly a single-sided adhesive sheet with a substrate made of a porous substrate.
The surface of the adhesive tape on the substrate side is attached to the entire surface or a predetermined portion of the fixing plate using an adhesive to form a fixing plate having an adhesive layer of the adhesive tape on the surface, and the surface of the adhesive layer FP
C can be attached and fixed.

In the present invention, after the electronic component is mounted on the FPC, the FPC on which the electronic component is mounted is peeled off from the adhesive layer.
N / 20 mm or less (for example, 0.5 to 7 N / 20 m
m), and more preferably 1 to 6 N / 20 mm. When a double-sided adhesive sheet is used as shown in FIG. 1, the adhesive strength between the adhesive sheet and the fixing plate can be selected from the same range as the adhesive strength between the adhesive sheet and the FPC. In the present invention, the adhesive strength of the adhesive sheet can be adjusted by appropriately selecting the type of the pressure-sensitive adhesive and the additives and the mixing ratio thereof.

The guide pins (71, 72) and the fixing table 8 for conveyance are not particularly limited, and can be appropriately selected according to a device for mounting electronic components on the FPC (particularly, an automatic mounting device). .

As described above, according to the method of the present invention, the FPC can be fixed only by placing the FPC on the adhesive layer provided on the fixing plate and sticking it. There is no. Further, to remove the FPC from the fixing plate, it is only necessary to remove the FPC on which the electronic components are mounted, and it is not necessary to remove the adhesive tape as in the related art. Therefore, the workability in attaching and detaching the FPC to and from the fixing plate can be greatly improved, and the FPC can be performed quickly.
Manufacturing costs can also be reduced.

Further, since the entire surface of the FPC can be fixed to the fixing plate by sticking, it is possible to fix the FPC firmly and fix the fixing plate (especially the adhesive layer formed on the surface of the fixing plate). ) And FPC with little or no gap. Therefore, when the electronic component is mounted on the FPC, there is no displacement or the like, so that the electronic component can be mounted with high positional accuracy.

Further, as described above, even after a heating step (such as an IR heating step), the adhesiveness of the adhesive layer by the adhesive hardly or not decreases, so that the FPC does not have a positional shift after heating. . Therefore, it is possible to mount the electronic component on the FPC with high positional accuracy. That is,
The positional accuracy of mounting the electronic component on the FPC can be significantly improved. Furthermore, when an adhesive sheet with a porous substrate is used as the FPC fixing adhesive sheet (particularly, a double-sided adhesive sheet), as described above, even after the heating step, the generated gas component such as water vapor is removed. Since the FPC can be released to the outside of the system through the porous substrate, the FPC can be kept fixed at a predetermined site with little or no decrease in adhesive strength. Moreover, after mounting the electronic component on the FPC, the FPC can be easily peeled off from the adhesive layer on the surface of the fixing plate.

Therefore, the method of the present invention is extremely useful as a method for mounting an electronic component on a flexible printed wiring board.

The electronic components mounted on the FPC are not particularly limited. For example, an IC, a capacitor, a connector, a resistor, an LED (Light Emitting Diode; Light Em)
Itting Diode).

[0049]

Next, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples. In the following, “parts” means “parts by weight”.

Example 1 An acrylic rubber (trade name “Leocoat R5000” manufactured by Toray Cotex) was dissolved in toluene to prepare a solution having a base polymer content of 15% by weight. To 100 parts of this solution, 5 parts of an isocyanate-based crosslinking agent (trade name "Coronate L" manufactured by Nippon Polyurethane Industry Co., Ltd.) was added and mixed to prepare a pressure-sensitive adhesive composition. After applying the pressure-sensitive adhesive composition to a separator, the adhesive composition was dried at 130 ° C. for 5 minutes in a hot air drier to a thickness of 50 μm.
A μm adhesive layer (pressure-sensitive adhesive layer) was formed. This adhesive layer was transferred to both surfaces of a porous substrate (trade name “NOMEX” manufactured by DuPont) made of aramid fiber as a porous substrate, to prepare a double-sided adhesive sheet with the porous substrate. Then, one side of the double-sided adhesive sheet was bonded to an aluminum plate to produce a fixing plate having an adhesive layer on the surface.

(Example 2) A pressure-sensitive adhesive composition was prepared by mixing and stirring 2.0 parts of benzoyl peroxide and toluene with 100 parts of a silicone polymer (trade name "SH4280" manufactured by Dow Corning Toray Silicone Co., Ltd.). Was prepared. After applying the pressure-sensitive adhesive composition on a separator,
A drying treatment was performed at 70 ° C. for 5 minutes to form a sticky layer (pressure-sensitive adhesive layer) having a thickness of 25 μm. This adhesive layer was transferred to both sides of Japanese paper as a porous substrate to prepare a double-sided adhesive sheet with a substrate using the porous substrate. Then, one side of the double-sided adhesive sheet was bonded to an aluminum plate to produce a fixing plate having an adhesive layer on the surface.

Example 3 100 parts of 2-ethylhexyl acrylate and 2 parts of 2-hydroxyethyl acrylate
In 10 parts of toluene, 60 to 8 parts in the presence of 0.2 parts of benzoyl peroxide and 0.01 part of trimethylolpropane triacrylate (crosslinking agent) in the coexistence of a nitrogen atmosphere.
A solution polymerization treatment was carried out while stirring at 0 ° C. to prepare a pressure-sensitive adhesive solution (pressure-sensitive adhesive solution) having a viscosity of about 120 poise, a polymerization rate of 99.2%, and a solid content of 30.0% by weight. Then, 5 parts of an isocyanate-based crosslinking agent (trade name “Coronate L” manufactured by Nippon Polyurethane Industry Co., Ltd.) was added and mixed to prepare a pressure-sensitive adhesive composition. After applying the pressure-sensitive adhesive composition to a separator, a drying treatment was performed at 40 ° C. for 5 minutes in a hot air drier,
Further, it is dried at 130 ° C. for 5 minutes and has a thickness of 50 μm.
(Pressure-sensitive adhesive layer) was formed. This adhesive layer was transferred to both surfaces of a nonwoven fabric (basis weight: 23 g / m ² ) made of rayon fiber as a porous base material to prepare a double-sided adhesive sheet with a porous base material. Then, one side of the double-sided adhesive sheet was bonded to an aluminum plate to produce a fixing plate having an adhesive layer on the surface.

Comparative Example 1 An aluminum plate was used as a fixing plate. That is, the fixing plate according to Comparative Example 1 is made of only an aluminum plate, and has no adhesiveness on the surface as in Examples 1 to 3.

(Evaluation) Examples 1 to 3 and Comparative Example 1
The time required for fixing the FPC for the fixing plate according to
The gap between the FPC and the fixing plate when the PC was bonded to the fixing plate, and the time required for removing the FPC were measured by the following methods to evaluate the workability and the fixing state of the FPC.

(Time Required for Fixing FPC)
As for the fixing plate according to 3, as shown in FIG.
6 FPs per fixed plate with adhesive layer on the surface
After each of C was aligned, it was placed on the adhesive layer formed on the surface of the fixing plate, and was pressed and adhered by hand to fix the FPC to the fixing plate. On the other hand, regarding the fixing plate according to Comparative Example 1, as shown in FIG. 4, six FPCs were aligned with respect to one fixing plate, and then placed on the fixing plate. An adhesive tape (an adhesive tape in which a silicone-based adhesive was applied to one surface of a substrate made of polyimide) was attached to four corners of one FPC, and the FPC was fixed to a fixing plate. The time (second) required for fixing the FPC to the fixing plate was measured. The evaluation results are shown in the column of "Time required for FPC fixing" in Table 1.

(Gap Between FPC and Fixed Plate) With respect to the fixed plate to which the FPC was fixed in the measurement of the time required for fixing the FPC, the gap between the FPC and the fixed plate (m
m) is measured, and the FPC when the FPC is bonded to the fixing plate is measured.
The gap (mm) between the PC and the fixing plate was examined. The evaluation results are shown in the column of "gap between FPC and fixed plate" in Table 1.

(Time required for removing FPC)
After measuring the gap between the PC and the fixing plate, the electronic component is mounted on the FPC, and after the mounting is completed, the FPC on which the electronic component is mounted.
Was removed with tweezers. In the fixing plate according to Comparative Example 1, the adhesive tape attached to the four corners of the FPC was peeled off, and then the FPC on which the electronic components were mounted was removed with tweezers. The time (second) required for removing the FPC from the fixing plate was measured. Table 1 shows the evaluation results.
In the column "Time required for FPC removal".

[0058]

[Table 1]

From Table 1, it can be seen that the time required for mounting and the time required for removing the fixing plates of Examples 1 to 3 having an adhesive layer on their surfaces are extremely short, and workability is excellent. In addition, there is almost no gap between the FPC and the fixing plate.
The PC is firmly adhered to the fixing plate, so that the FPC does not shift.

[0060]

According to the method of the present invention, since the adhesive layer is provided on the surface of the fixing plate, the flexible printed wiring board can be easily attached to and detached from the fixing plate, and the flexible printed wiring can be easily formed. The plate can be firmly fixed to the fixing plate. Therefore, the flexible printed wiring board can be attached to and detached from the fixed plate with excellent workability. Moreover, electronic components can be mounted on the flexible printed wiring board with high accuracy.

[Brief description of the drawings]

FIG. 1 is a schematic view showing a state in which an FPC is attached to a fixing plate, and FIG. 1 (a) is a view seen from above, and FIG.
(B) is the figure seen from the side.

FIG. 2 is a cross-sectional view illustrating an example of an adhesive sheet according to the present invention.

FIG. 3 is a sectional view showing another example of the adhesive sheet according to the present invention.

FIG. 4 is a schematic view showing a typical example of a conventional FPC fixing method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Adhesive sheet for fixing a flexible printed wiring board 2 Adhesive layer 3 Base 11 Adhesive sheet for fixing a flexible printed wiring board 21 Adhesive layer 31 Substrate 4 Flexible printed wiring board 5 Double-sided adhesive sheet 51 Adhesive layer of double-sided adhesive sheet 5 6 Fixing plate (motherboard) 71 Guide pin for fixing motherboard 72 Guide pin for positioning FPC 71a Perforation for inserting guide pin 71 for fixing motherboard 72a Perforation for inserting guide pin 72 for positioning FPC 8 Fixing table for transport 9 Adhesion tape

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Takeshi Sano 1-1-2 Shimohozumi, Ibaraki-shi, Osaka Nitto Denko Corporation (72) Inventor Hiroshi Yamamoto 1-1-2 Shimohozumi, Ibaraki-shi, Osaka F-term (reference) in Nitto Denko Corporation 5E319 AC03 CC45 CD15 CD46 GG15

Claims (3)

[Claims] When mounting an electronic component on the surface of a flexible printed wiring board, the flexible printed wiring board is fixed on the adhesive layer surface of a fixing plate having an adhesive layer on the surface, and then the flexible printed wiring board is mounted. A method for mounting an electronic component on a flexible printed wiring board, wherein the electronic component is mounted on a surface. 2. A fixing plate having an adhesive layer on its surface, wherein the adhesive layer of an adhesive sheet having an adhesive layer on at least one surface is on the surface side opposite to the fixing plate side. 2. The method for mounting an electronic component on a flexible printed wiring board according to claim 1, wherein the electronic component is mounted on one surface. 3. The mounting of an electronic component on a flexible printed wiring board according to claim 1, wherein the adhesive layer of the fixing plate to which the flexible printed wiring board is adhered is made of an adhesive having easy peelability. Method.