JP2015159171A - Manufacturing method of connection body, connection method of circuit member, and connection body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively prevent an alignment deviation in a connection process of a circuit member.SOLUTION: By fitting one second electrode terminal 6 formed on a second circuit member 3 between a pair of first electrode terminals 5 formed on a first electrode member 2, one connection part 7 between the first and second electrode terminals 5, 6 is formed. A guide surface 10 for aligning the first and second electrode terminals 5, 6 by sliding at least one of the first and second electrode terminals 5, 6 to the other electrode terminal is formed.

Description

  TECHNICAL FIELD The present invention relates to a method for manufacturing a connection body that connects circuit members to each other via an adhesive, and in particular, a method for manufacturing a connection body that can correct alignment misalignment between electrode terminals due to heating and pressing, and a circuit member connection method. And a connection body manufactured using the same.

  2. Description of the Related Art In the past, there has been a growing demand for downsizing, high density, and high functionality of electronic devices, connection between flexible printed wiring boards, flexible printed wiring boards and rigid printed wiring boards, or ICs on flexible printed wiring boards. In order to mount package parts such as LSIs and chip parts such as resistors and capacitors, anisotropic conductive films capable of easily connecting the terminals of these members are widely used.

  An anisotropic conductive film is made of a resin composition in which conductive particles are dispersed in an ordinary binder (adhesive) containing, for example, a film-forming resin, a thermosetting resin, a latent curing agent, a silane coupling agent, and the like. The resin composition is formed on a release film such as PET to form a film.

  This anisotropic conductive film is disposed between electrode terminals of circuit members such as flexible printed wiring boards and various electronic components, and is heated and pressed between the circuit members by a thermocompression bonding head, thereby providing conductivity between both electrode terminals. The binder is thermoset while the particles are sandwiched. Thereby, an anisotropic conductive film aims at the electrical connection of both electrode terminals, and the mechanical connection between circuit members.

JP 2005-26492 A

  Here, when the electrode terminals of the circuit members are connected to each other, alignment is performed between the electrode terminals previously formed on one circuit member and the electrode terminals formed on the other circuit member. In addition, with the recent miniaturization and high definition of electronic equipment, the fine pitch of wiring pitches of circuit members has been advanced, so that high precision alignment adjustment is required for electrode terminals of circuit boards.

  However, when anisotropically connected to a circuit member such as a flexible printed circuit board, misalignment between the electrode terminals may occur in the heating and pressing process by the thermocompression bonding head, leading to an increase in conduction resistance between the electrode terminals. There is.

  In addition, even if the alignment deviation between the electrodes is within an allowable range at the initial stage of connection, warpage occurs due to the difference in the linear expansion coefficient of the circuit member in the subsequent environmental test, and the alignment deviation between the electrode terminals spreads and becomes conductive. There was a concern of increased resistance and poor connection.

  For this reason, the connection body in which the alignment deviation between the circuit members has occurred needs to be mechanically peeled off and then reconnected after washing the adhesive, which complicates the manufacturing process.

  Moreover, since the connection method using an anisotropic conductive film requires many electroconductive particles including the part which is not pinched between electrode terminals and does not contribute to conduction | electrical_connection, it becomes high cost. For this reason, there is a method using an insulating adhesive, but since the conduction resistance is increased, it is necessary to take measures such as forming solder bumps on the electrode terminals and heating them at a temperature higher than the melting point of the solder. However, heat pressurization at a high temperature has a large thermal shock on the circuit member, and there is a problem that a separate measure is required.

  Therefore, the present invention provides a connection body manufacturing method, a circuit member connection method, and a connection body manufactured using the same, which can effectively prevent misalignment in the circuit member connection step. With the goal.

  In order to solve the above-described problem, a method for manufacturing a connection body according to the present invention is the method for manufacturing a connection body in which the electrode terminals of the first circuit member and the electrode terminals of the second circuit member are connected. By fitting one second electrode terminal formed on the second circuit member between a pair of first electrode terminals formed on the first circuit member, the first and second electrodes are formed. The first and second electrode terminals are aligned by sliding at least one of the first and second electrode terminals to the other electrode terminal. The guide surface to be performed is formed.

  The circuit member connection method according to the present invention is the circuit member connection method in which the electrode terminal of the first circuit member and the electrode terminal of the second circuit member are connected by an adhesive. By fitting one second electrode terminal formed on the second circuit member between the pair of first electrode terminals formed between the first and second electrode terminals, One connection is formed, and at least one of the first and second electrode terminals slides on the other electrode terminal, thereby forming a guide surface for aligning the first and second electrode terminals. It is what.

  Moreover, the connection body which concerns on this invention is manufactured by the said method.

  According to the present invention, when the first and second circuit members are connected, the second electrode terminal is inserted between the pair of first electrode terminals. At this time, since one electrode terminal slides on the guide surface of the other electrode terminal, the second electrode terminal is guided and fitted at a predetermined position between the pair of first electrode terminals. Therefore, even when the first and second circuit members are opposed to each other, even if the alignment is misaligned, the misalignment is corrected when the first and second electrode terminals are connected, and the first and second electrodes are surely connected. The terminal can be made conductive.

FIG. 1 is a perspective view showing a connection body according to the present invention. FIG. 2 is a cross-sectional view of the connection body. FIGS. 3A and 3B are diagrams showing a connection process of the first and second circuit members, where FIG. 3A is a state where the electrode terminals are guided by the guide surface, and FIG. Indicates the state. FIG. 4 is a cross-sectional view illustrating a state in which the first and second electrode terminals having a plating layer formed on the surface are connected. FIG. 5 is a cross-sectional view showing a connection process of other first and second circuit members. FIG. 6 is a cross-sectional view showing a connection process of other first and second circuit members. FIG. 7 is a cross-sectional view showing a connection process of other first and second circuit members. FIG. 8 is a cross-sectional view showing a connecting step of other first and second circuit members. FIG. 9 is a cross-sectional view showing a connection process of other first and second circuit members. FIG. 10 is a cross-sectional view showing an insulating adhesive film. FIG. 11 is a cross-sectional view illustrating the connection process of the first and second circuit members according to the first and fifth embodiments. FIG. 12 is a cross-sectional view illustrating the connection process of the first and second circuit members according to the second embodiment. FIG. 13 is a cross-sectional view illustrating the connection process of the first and second circuit members according to the third embodiment. FIG. 14 is a cross-sectional view illustrating the connection process of the first and second circuit members according to the fourth embodiment. FIG. 15 is a cross-sectional view illustrating the connection process of the first and second circuit members according to the first comparative example. FIG. 16 is a cross-sectional view illustrating the connection process of the first and second circuit members according to the second comparative example.

  Hereinafter, a connection body manufacturing method, a circuit member connection method, and a connection body to which the present invention is applied will be described in detail with reference to the drawings. It should be noted that the present invention is not limited to the following embodiments, and various modifications can be made without departing from the scope of the present invention. Further, the drawings are schematic, and the ratio of each dimension may be different from the actual one. Specific dimensions should be determined in consideration of the following description. Moreover, it is a matter of course that portions having different dimensional relationships and ratios are included between the drawings.

  The connection body manufacturing method according to the present invention is used for manufacturing a connection body in which a first circuit member and a second circuit member are connected by an adhesive. For example, a rigid printed wiring board is used as the first circuit member. Can be used for so-called FOB connection using a flexible substrate as the second circuit member. The connection body manufacturing method according to the present invention includes so-called FOF connection using a flexible substrate as the first and second circuit members, and package components such as IC and LSI, resistors, and capacitors as the first circuit members. Such chip components can be used for so-called COF connection and COB connection to be connected to a flexible printed circuit board or a rigid printed wiring board as the second circuit member.

  In the following, referring to FIG. 1, a rigid printed wiring board 2 is used as the first circuit member, and a flexible circuit serving as the second circuit member is formed on the printed wiring board 2 via an insulating adhesive 4. A method for manufacturing the connection body 1 to which the substrate 3 is connected will be described as an example.

[Printed wiring boards / flexible boards]
The printed wiring board 2 is a substrate used in various electronic devices. For example, a package component such as an IC or LSI, or a chip component such as a resistor or a capacitor is mounted thereon, and a first electrode terminal 5 is formed. The printed wiring board 2 is formed using, for example, a glass epoxy substrate. The 1st electrode terminal 5 is connected with the 2nd electrode terminal 6 formed in the flexible substrate 3, and is a predetermined pattern on the printed wiring board 2 with copper or an alloy containing copper as a main component. Is formed.

  Various circuit patterns are formed on the flexible substrate 3, and second electrode terminals 6 connected to the first electrode terminals 5 provided on the printed wiring board 2 are formed. The flexible substrate 3 is formed using, for example, a polyimide substrate. Each second electrode terminal 6 is formed in a predetermined pattern on the flexible substrate 3 from copper or an alloy containing copper as a main component.

[First and second electrode terminals]
A pair of first electrode terminals 5 is provided for one second electrode terminal 6, and one second electrode terminal 6 is fitted between the pair of first electrode terminals 5. Electrically connected. As shown in FIG. 1, the first electrode terminals 5 are branched into a pair in a terminal region 8 to which the flexible substrate 3 is connected from one main wiring 9. And a pair of 1st electrode terminal 5 and one 2nd electrode terminal 6 form one connection part 7 by connecting.

  The printed wiring board 2 includes a pair of first electrode terminals 5 branched from one main wiring 9 as shown in FIG. 1 and only one of the pair of first electrode terminals 5 is connected to the main wiring 9. The other of the continuous first electrode terminals 5 may be an electrode pattern formed independently of the main wiring.

  Further, the first electrode terminal 5 and the second electrode terminal 6 are opposed to each other via an adhesive 4 described later, and then thermally pressed by a thermocompression bonding head (not shown), whereby a pair of first electrodes When the second electrode terminal 6 slides between the electrode terminals 5, mutual alignment is taken.

  For example, as shown in FIG. 2, the pair of first electrode terminals 5 are formed in a rectangular cross section, and the second electrode terminal 6 is formed by sliding the first electrode terminal 5 to the second electrode terminal 6. A guide surface 10 is formed to guide the lens to a predetermined connection position. The guide surface 10 is constituted by tapered surfaces formed on both side surfaces of the trapezoid by forming the second electrode terminal 6 in a trapezoidal cross section.

  As shown in FIG. 3A, when the printed wiring board 2 and the flexible substrate 3 are pressed against the thermocompression bonding head, the second electrode terminal 6 is inserted between the pair of first electrode terminals 5. At this time, since the corner portion 5a of the first electrode terminal 5 slides on the guide surface 10 of the second electrode terminal 6, as shown in FIG. It is guided and fitted in a predetermined position between the one electrode terminals 5. Therefore, when the printed wiring board 2 and the flexible substrate 3 are opposed to each other, even if the alignment is shifted from the position shown in FIG. 3B, the alignment is shifted when the first and second electrode terminals 5 and 6 are connected. Is corrected, and the first and second electrode terminals 5 and 6 can be reliably conducted.

  In addition, the first and second electrode terminals 5 and 6 are crushed when the corner portion 5a of the first electrode terminal 5 is pressed against the guide surface 10 of the second electrode terminal 6, and the first and second electrode terminals 5 and 6 are crushed. As the contact area between the electrode terminals 5 and 6 increases, the electrode terminals 5 and 6 are firmly connected. Therefore, the connection body 1 can maintain good electrical conductivity between the first and second electrode terminals 5 and 6 even after the initial connection and after the environmental test.

  Here, as shown in FIG. 3, when the height of the first electrode terminal 5 is a and the height of the second electrode terminal 6 is a ′, a ′ ≦ a. Further, the width of the side of the second electrode terminal 6 formed in the trapezoidal shape on the substrate side is c, the width of the pair of first electrode terminals 5 is b, and the side of the second electrode terminal 6 on the substrate side And b ′ <b <c, where b ′ is the width of the side on the front end side that faces.

  When a ′ ≦ a is not satisfied, that is, when the height a of the first electrode terminal 5 is lower than the height a ′ of the second electrode terminal 6, the corner 5a of the first electrode terminal 5 and the second There is a possibility that the guide surface 10 of the electrode terminal 6 does not slide and the first and second electrode terminals 5 and 6 are not connected.

  If b ′ <b is not satisfied, that is, if the width b ′ of the side on the distal end side of the second electrode terminal 6 is wider than the inter-terminal width b of the pair of first electrode terminals 5, the second electrode The terminal 6 cannot be inserted between the pair of first electrode terminals 5. If b <c is not satisfied, that is, if the inter-terminal width b of the pair of first electrode terminals 5 is wider than the width c of the side of the second electrode terminal 6 on the substrate side, the first electrode terminals 5 There is a possibility that the corner portion 5a and the guide surface 10 of the second electrode terminal 6 do not slide and the first and second electrode terminals 5 and 6 are not connected.

  The second electrode terminal 6 having a trapezoidal cross section formed with the guide surface 10 can be formed by etching copper or a metal layer containing copper as a main component. The dimensions such as the height of the trapezoidal cross section and the angle of the tapered surface can be designed to the desired dimensions by appropriately adjusting the etching factor by adjusting the etching spray pressure and the line speed.

  Further, the first electrode terminal 5 having a rectangular cross section can be formed on the surface of the printed wiring board 2 by electroless plating. In addition, the first electrode terminal 5 can also be formed by an additive method such as electrolytic plating, vapor deposition, or printing of a conductive paste.

  Further, as shown in FIG. 4, the first electrode terminal 5 is formed of copper or metal wiring mainly composed of copper, and nickel plating or aluminum plating is performed to form the first plating layer 20. Also good. Further, the second electrode terminal 6 may be formed of copper or a metal wiring mainly composed of copper, and the second plating layer 21 may be formed by performing gold plating on the surface. The gold plating thickness is preferably about 0.3 μm or more.

  Thus, when the first and second electrodes 5 and 6 are pressed, the first plating layer 20 formed on the surface of the first electrode terminal 5 and the surface of the second electrode terminal 6 are formed. Further, the second plating layer 21 is squeezed with each other, and the contact area is further expanded and the second plating layer 21 is firmly connected. Therefore, the connection body 1 can further ensure good electrical conductivity between the first and second electrode terminals 5 and 6. In the printed wiring board 2, instead of forming the first plating layer made of nickel plating or aluminum plating on the first electrode terminal 5, the first electrode terminal 5 may be formed of nickel electrode or aluminum electrode. Good.

[Modification]
In the above description, the pair of first electrode terminals 5 are formed in a rectangular cross section, and the second electrode terminal 6 is formed in a trapezoidal cross section. However, as shown in FIG. May be formed in a trapezoidal cross section, and the second electrode terminal 6 may be formed in a rectangular cross section. The first electrode terminal 5 having a trapezoidal cross section can also be formed by an etching method. The second electrode terminal 6 having a rectangular cross section can also be formed by the additive method.

  Further, in the above, the first electrode terminals 5 formed on the printed wiring board 2 are formed in a pair, and the second electrode terminals 6 formed on the flexible substrate 3 are formed in one, but as shown in FIG. As described above, the first electrode terminals 5 formed on the printed wiring board 2 may be formed as one, and the second electrode terminals 6 formed on the flexible substrate 3 may be formed as a pair. Also in this case, the first electrode terminal 5 formed on the printed wiring board 2 may be formed in a rectangular cross section, and the second electrode terminal 6 formed on the flexible substrate 3 may be formed in a trapezoidal cross section. As shown in FIG. 7, the first electrode terminal 5 formed on the printed wiring board 2 is formed in a trapezoidal cross section, and the second electrode terminal 6 formed on the flexible substrate 3 is formed in a rectangular cross section. Also good.

  Furthermore, this connection method uses so-called FOF connection using a flexible substrate as the first and second circuit members, and package components such as IC and LSI, and chip components such as resistors and capacitors as the first circuit members. The same applies to so-called COF connection and COB connection that are connected to a flexible substrate or a rigid printed wiring board as the second circuit member. That is, the first electrode terminal 5 may be formed in a trapezoidal cross section, and the second electrode terminal 6 may be formed in a rectangular cross section. Conversely, the first electrode terminal 5 is formed in a rectangular cross section, The second electrode terminal 6 may be formed in a trapezoidal cross section. Alternatively, the first electrode terminal 5 may be formed in a pair and the second electrode terminal 6 may be formed in one, and conversely, the first electrode terminal 5 may be formed in one and the second electrode A pair of terminals 6 may be formed.

  Moreover, in each said structure, although one of the 1st, 2nd electrode terminals 5 and 6 was formed in the cross-sectional trapezoid shape, and the other was formed in the cross-sectional rectangular shape, in this connection body 1, as shown in FIG. Both the first and second electrode terminals 5 and 6 may be formed in a trapezoidal cross section. At this time, the angle of the tapered surface of the first electrode terminal 5 is made different from the angle of the tapered surface of the second electrode terminal 6. Thereby, when the 1st, 2nd electrode terminals 5 and 6 are attached, the other corner | angular part is guided by one taper surface, and alignment shift | offset | difference can be correct | amended.

  In the above configuration, the first and / or second electrode terminals 5 and 6 are formed in a trapezoidal cross section, and the tapered surface thereof is used as the guide surface 10. However, as shown in FIG. The second electrode terminals 5 and 6 may be formed in a semicircular cross section projecting from the tip, and the arc surface thereof may be used as the guide surface 10 so that the mutual misalignment can be corrected by sliding on each other. .

  Moreover, in the said structure, although all the connection parts 7 in which the electrode terminals of the printed wiring board 2 and the flexible substrate 3 were connected were formed by connecting a pair of electrode terminal and one electrode terminal, a connection part A part of 7 may be formed by a pair of electrode terminals and one electrode terminal. For example, in the middle of the electrode terminals arranged on the printed wiring board 2 and the flexible substrate 3, one or a plurality of connection portions 7 at one end or both ends, a pair of first electrode terminals 5 and a single second electrode terminal 6 are provided. Others may be formed by connecting one electrode terminal as in the conventional case.

  Also in this case, all the electrodes of the printed wiring board 2 and the flexible substrate 3 are corrected by correcting the misalignment when the pair of first electrode terminals 5 and one second electrode terminal 6 are connected. It is possible to correct misalignment between terminals.

[adhesive]
Next, the adhesive 4 that connects the printed wiring board 2 and the flexible substrate 3 will be described. As the adhesive 4, an insulating adhesive film (NCF) 4 a can be suitably used. As shown in FIG. 10, the insulating adhesive film 4 a is generally obtained by forming a binder resin layer (adhesive layer) 12 on a release film 11 serving as a base material. The insulating adhesive film 4a is a thermosetting adhesive or a photo-curing adhesive such as ultraviolet rays, and is adhered to the terminal area 8 of the printed wiring board 2 where the first electrode terminals 5 are formed, and the flexible substrate 3. And is fluidized by being thermally pressurized by the thermocompression bonding head and flows out between the first and second electrode terminals 5 and 6, and the first and second electrode terminals 5 and 6 are connected. In the state, it is cured by heating or ultraviolet irradiation. Thereby, the insulating adhesive film 4a can connect the printed wiring board 2 and the flexible substrate 3, and can be made conductive.

  The insulating adhesive film 4a is composed of a normal binder resin layer 12 containing a film-forming resin, a thermosetting resin, a latent curing agent, a silane coupling agent, and the like.

  The release film 11 that supports the binder resin layer 12 includes, for example, a release agent such as silicone on PET (Poly Ethylene Terephthalate), OPP (Oriented Polypropylene), PMP (Poly-4-methylpentene-1), PTFE (Polytetrafluoroethylene), and the like. It is applied and prevents the insulating adhesive film 4a from drying, and maintains the shape of the insulating adhesive film 4a.

  The film forming resin contained in the binder resin layer 12 is preferably a resin having an average molecular weight of about 10,000 to 80,000. Examples of the film forming resin include various resins such as an epoxy resin, a modified epoxy resin, a urethane resin, and a phenoxy resin. Among these, phenoxy resin is particularly preferable from the viewpoint of film formation state, connection reliability, and the like.

  It does not specifically limit as a thermosetting resin, For example, a commercially available epoxy resin, an acrylic resin, etc. are mentioned.

  The epoxy resin is not particularly limited. For example, naphthalene type epoxy resin, biphenyl type epoxy resin, phenol novolac type epoxy resin, bisphenol type epoxy resin, stilbene type epoxy resin, triphenolmethane type epoxy resin, phenol aralkyl type epoxy resin. Naphthol type epoxy resin, dicyclopentadiene type epoxy resin, triphenylmethane type epoxy resin and the like. These may be used alone or in combination of two or more.

  There is no restriction | limiting in particular as an acrylic resin, According to the objective, an acrylic compound, liquid acrylate, etc. can be selected suitably. For example, methyl acrylate, ethyl acrylate, isopropyl acrylate, isobutyl acrylate, epoxy acrylate, ethylene glycol diacrylate, diethylene glycol diacrylate, trimethylolpropane triacrylate, dimethylol tricyclodecane diacrylate, tetramethylene glycol tetraacrylate, 2-hydroxy- 1,3-diacryloxypropane, 2,2-bis [4- (acryloxymethoxy) phenyl] propane, 2,2-bis [4- (acryloxyethoxy) phenyl] propane, dicyclopentenyl acrylate, tricyclo Examples include decanyl acrylate, tris (acryloxyethyl) isocyanurate, urethane acrylate, and epoxy acrylate. In addition, what made acrylate the methacrylate can also be used. These may be used individually by 1 type and may use 2 or more types together.

  The latent curing agent is not particularly limited, and examples thereof include various curing agents such as a heat curing type and a UV curing type. The latent curing agent does not normally react, but is activated by various triggers selected according to applications such as heat, light, and pressure, and starts the reaction. The activation method of the thermal activation type latent curing agent includes a method of generating active species (cation, anion, radical) by a dissociation reaction by heating, etc., and it is stably dispersed in the epoxy resin near room temperature, and epoxy at high temperature There are a method of initiating a curing reaction by dissolving and dissolving with a resin, a method of initiating a curing reaction by eluting a molecular sieve encapsulated type curing agent at a high temperature, and an elution / curing method using microcapsules. Thermally active latent curing agents include imidazole, hydrazide, boron trifluoride-amine complexes, sulfonium salts, amine imides, polyamine salts, dicyandiamide, etc., and modified products thereof. The above mixture may be sufficient. Among these, a microcapsule type imidazole-based latent curing agent is preferable.

  Although it does not specifically limit as a silane coupling agent, For example, an epoxy type, an amino type, a mercapto sulfide type, a ureido type etc. can be mentioned. By adding the silane coupling agent, the adhesion at the interface between the organic material and the inorganic material is improved.

  The adhesive composition constituting the binder resin layer 12 is not limited to the case where it contains a film-forming resin, a thermosetting resin, a latent curing agent, a silane coupling agent, etc. You may make it comprise any material used as an adhesive composition.

  The insulating adhesive film 4a may be produced by any method, for example, it can be produced by the following method. An adhesive composition containing a film-forming resin, a thermosetting resin, a latent curing agent, a silane coupling agent, and the like is prepared. The adjusted adhesive composition is applied onto the release film 11 using a bar coater, a coating device, and the like, and dried by an oven or the like, whereby the insulating adhesive film 4a in which the binder resin layer 12 is supported on the release film 11 is obtained. obtain.

  The shape of the insulating adhesive film 4a is not particularly limited. For example, as shown in FIG. 10, the insulating adhesive film 4a is cut into a predetermined length by making it into a long tape shape that can be wound around the take-up reel 13. Can be used.

  Moreover, in the above-mentioned embodiment, although the adhesive film which shape | molded the thermosetting resin composition in the film form was demonstrated to the example as the insulating adhesive film 4a, the adhesive agent which concerns on this invention is not limited to this. For example, an insulating adhesive paste made of the binder resin described above may be used.

[Connection process]
Next, a connection process for connecting the flexible substrate 3 to the printed wiring board 2 will be described. In the connection step, first, the insulating adhesive film 4a is temporarily attached to the terminal region 8 where the first electrode terminal 5 of the printed wiring board 2 is formed, and the alignment adjustment of the first and second electrode terminals 5 and 6 is performed. Then, the flexible substrate 3 is temporarily disposed in the terminal region 8 of the printed wiring board 2 via the insulating adhesive film 4a. Next, the printed wiring board 2 is placed on the stage of the connection device. Thereby, the flexible substrate 3 is opposed to the thermocompression bonding head that stands by above the stage.

  Subsequently, the thermocompression bonding head heated to a predetermined temperature for curing the binder resin layer 12 is hot-pressed from above the flexible substrate 3 at a predetermined pressure and time. The heat press condition by the thermocompression bonding head is set to a predetermined temperature (for example, 190 ° C.), pressure (for example, 4 MPa), and time (for example, 10 seconds) for curing the binder resin layer 12. As a result, the binder resin layer 12 of the insulating adhesive film 4a exhibits fluidity and flows out from between the first electrode terminal 5 of the printed wiring board 2 and the second electrode terminal 6 of the flexible substrate 3, and a pair of The second electrode terminal 6 is inserted between the first electrode terminals 5. At this time, since the corner portion 5a of the first electrode terminal 5 slides on the guide surface 10 of the second electrode terminal 6, the second electrode terminal 6 has a pair of first electrodes as shown in FIG. It is guided to a predetermined position between one electrode terminal 5. Therefore, even when the printed wiring board 2 and the flexible substrate 3 are opposed to each other, the first and second electrode terminals 5 and 6 are connected as shown in FIGS. Sometimes the misalignment is corrected, and all the first and second electrode terminals 5 and 6 can be made conductive.

  In addition, the first and second electrode terminals 5 and 6 are crushed when the corner portion 5a of the first electrode terminal 5 is pressed against the guide surface 10 of the second electrode terminal 6, and the first and second electrode terminals 5 and 6 are crushed. As the contact area between the electrode terminals 5 and 6 increases, the electrode terminals 5 and 6 are firmly connected.

  The binder resin of the insulating adhesive film 4a is cured by heating or ultraviolet irradiation in a state where the first and second electrode terminals 5 and 6 are connected. Thereby, the connection body 1 in which the printed wiring board 2 and the flexible substrate 3 are electrically and mechanically connected is manufactured.

  In addition, by using a fast curing type radical polymerization reaction system as the binder resin, the binder resin can be rapidly cured even with a short heating time. Further, the insulating adhesive film 4a is not limited to the thermosetting type, and may be a photo-curing type or a photo-heat combined type adhesive as long as pressure connection is performed.

  Next, examples of the present invention will be described. In this example, so-called FOF connection for connecting flexible substrates was performed, and the connection resistance after the initial and environmental tests was measured.

[Insulating adhesive film]
As the insulating adhesive film for connecting the flexible substrates, the following two types having different minimum melt viscosities were prepared.

  The insulating adhesive film 1 was prepared as follows. As a cationic polymerizable resin, 40 parts by weight of Bis-A / Bis-F mixed phenoxy resin (jER-4210; manufactured by Japan Epoxy Resin Co., Ltd.) having an average molecular weight of 30000, 190 equivalents of liquid Bis-A type epoxy resin (YL980; Japan) 20 parts by weight of Epoxy Resin Co.) and 10 parts by weight of an equivalent 160 liquid Bis-F type epoxy resin (jER806; Japan Epoxy Resin Co., Ltd.) were used. As a stress relaxation agent, 5 parts by weight of butadiene rubber (BR) particles having an average particle diameter of 0.5 μm made of polybutadiene (RKB; manufactured by Resin Chemical Co., Ltd.) was used. Moreover, 5 parts by weight of a sulfonium-based cationic curing agent (SI-60L; manufactured by Sanshin Chemical Industry Co., Ltd.) was used as the latent curing agent. Then, a cationic polymerizable resin, a stress relaxation agent, and a latent curing agent were dissolved in a solvent toluene to prepare an insulating adhesive resin solution. Furthermore, this insulating adhesive resin solution was coated on a peeling PET film so that the thickness after drying was 25 μm, and an anisotropic conductive film was obtained. This anisotropic conductive film was cut into a slit shape having a width of 2 mm to obtain an insulating adhesive film 1 (NCF1).

  Moreover, it was 700 Pa.s when the minimum melt viscosity of the insulating adhesive film 1 was measured. The minimum melt viscosity was measured as follows. The insulating adhesive film 1 is overlaid so as to have a thickness of 500 μm, and using a melt viscometer (HAAKE Rheoless RS-150; manufactured by Thermo Fisher Scientific), the temperature rise temperature is 10 ° C./min, the frequency is 1 Hz, and the applied pressure is 1 N. The measurement was performed under the conditions of a measurement temperature range of 30 to 180 ° C.

  The insulating adhesive film 2 was prepared as follows. 20 parts by weight of Bis-A / Bis-F mixed phenoxy resin (jER-4210; manufactured by Japan Epoxy Resin Co., Ltd.) having an average molecular weight of 30000, and Bis-F type phenoxy resin (jER-4007P; Japan Epoxy Resin) having an average molecular weight of 20000 It was prepared by the same method as that for the insulating adhesive film 1 except that the binder solution was adjusted to 20 parts by weight) and used as the insulating adhesive film 2 (NCF2).

  Moreover, it was 300 Pa.s when the minimum melt viscosity of the insulating adhesive film 2 was measured. The measuring method of the minimum melt viscosity is the same as the measuring method of the insulating adhesive film 1.

[Anisotropic conductive film]
Moreover, the following anisotropic conductive films (ACF: Anisotropic Conductive Film) were prepared as an adhesive for connecting the flexible substrates according to the comparative example.

  The anisotropic conductive film is obtained by adding 5 parts by weight of conductive adhesive particles obtained by applying nickel-gold plating to benzoguanamine particles having an average particle diameter of 4 μm to the insulating adhesive resin solution used for the production of the insulating adhesive film 1 Was prepared by the same method as for the insulating adhesive film 1.

  Moreover, it was 700 Pa.s when the minimum melt viscosity of the anisotropic conductive film was measured. The measuring method of the minimum melt viscosity is the same as the measuring method of the insulating adhesive film 1.

[Example 1]
In the first embodiment, as shown in FIG. 11, a pair of rectangular electrode terminals (hereinafter referred to as “rectangular terminals”) are formed on one flexible substrate, and one cross section is formed on the other flexible substrate. A trapezoidal electrode terminal (hereinafter referred to as “trapezoidal terminal”) was formed. The width between the rectangular terminals is 26 μm, the width of the side of the trapezoidal terminal on the substrate side is 30 μm, and the width of the side on the tip side is 12 μm. The trapezoidal terminal was formed by an etching method, and the rectangular terminal was formed by an electrolytic plating method.

  In Example 1, the amount of deviation between the rectangular terminal and the trapezoidal terminal was 7 μm. Here, the amount of deviation between the rectangular terminal and the trapezoidal terminal is the amount of deviation from the ideal state where the center of the width direction of the trapezoidal terminal shown in FIG. Say. In Example 1, since the width of the tip side of the trapezoidal terminal formed in a symmetrical shape is 12 μm and the width between the rectangular terminals is 26 μm, the tip of the trapezoidal terminal is aligned with the upper side of the rectangular terminal if the misalignment is up to 7 μm. It can be inserted between the rectangular terminals without interference.

  Moreover, in Example 1, the flexible substrates were overlapped via the insulating adhesive film 1 and connected by heating and pressing from the flexible substrate side on which the trapezoidal terminals were formed. The heating and pressing conditions are 190 ° C., 4 MPa, and 10 seconds.

[Example 2]
In Example 2, as shown in FIG. 12, the same flexible substrate as in Example 1 was used, and a connection body was formed by heating and pressing from the flexible substrate side on which a pair of rectangular terminals were formed. Other conditions are the same as those in the first embodiment.

[Example 3]
In Example 3, as shown in FIG. 13, one rectangular terminal was formed on one flexible substrate, and a pair of trapezoidal terminals were formed on the other flexible substrate. The width of the side on the substrate side of the trapezoidal terminal is 30 μm, the width of the side on the tip side is 12 μm, the width between the trapezoidal terminals is 26 μm, and the width of the rectangular terminal is 30 μm. Moreover, in Example 3, the connection body was formed by heating and pressing from the flexible substrate side on which the rectangular terminals were formed. Other conditions are the same as those in the first embodiment.

[Example 4]
In Example 4, as shown in FIG. 14, a pair of rectangular terminals are formed on one flexible substrate, and nickel plating with a thickness of 5 μm is applied to the surface, and one trapezoidal terminal is formed on the other flexible substrate and is thick. Gold plating with a thickness of 0.35 μm was applied. The width between the nickel-plated rectangular terminals is 26 μm, the width of the side of the substrate side of the trapezoidal terminal subjected to gold plating is 30 μm, and the width of the side of the tip side is 12 μm. Moreover, in Example 4, the connection body was formed by heating and pressing from the flexible substrate side on which the trapezoidal terminals were formed. Other conditions are the same as those in the first embodiment.

[Example 5]
In Example 5, the insulating adhesive film 2 was used as an adhesive. Other conditions are the same as those in the first embodiment.

[Comparative Example 1]
In Comparative Example 1, as shown in FIG. 15, flexible substrates on which one trapezoidal terminal was formed were connected using an anisotropic conductive film. Each of the trapezoidal terminals has a substrate side width of 30 μm and a tip side width of 12 μm. Further, in Comparative Example 1, there is no deviation amount of the trapezoidal terminals of both flexible substrates, that is, in a state where the centers of the sides on the tip side of the both trapezoidal terminals are aligned and aligned, the connecting body is heated and pressed. Formed. The heating and pressing conditions are the same as in Example 1.

[Comparative Example 2]
In Comparative Example 2, as shown in FIG. 16, in the flexible substrate according to Comparative Example 1, the amount of displacement is 7 μm, that is, the connection body is pressed by heating and pressing in a state shifted by 7 μm from the position shown in FIG. Formed. Other conditions are the same as in Comparative Example 1.

  About the connection body sample which concerns on these Examples 1-5 and Comparative Examples 1-2, the connection resistance value after an initial stage and an environmental test is measured using a digital multimeter (digital multimeter 7561; Yokogawa Electric Corporation make). did. The environmental test conditions are 85 ° C., 85% RH, and 500 hr. As a result of the measurement, a resistance value of less than 0.1Ω was evaluated as ◎ (best), 0.1Ω or more, less than 0.3Ω was evaluated as ○ (good), and 0.3Ω or more was evaluated as × (defect) .

  In each of the examples, the alignment deviation between the rectangular terminal and the trapezoidal terminal, which was 7 μm, was automatically corrected by being heated and pressed when connecting the flexible substrates. As a result, as shown in Table 1, the connection resistance value was ◎ (best) or ◯ (good) both in the initial stage of the connection body according to each example and after the environmental test.

  In Comparative Example 1, when one trapezoidal terminal was ACF-connected with no misalignment, a good connection resistance value was obtained even in the initial connection and after the environmental test. However, when the connection was made under an alignment deviation of 7 μm, the alignment deviation was not automatically corrected, and the connection resistance value increased at the initial stage of connection and after the environmental test.

  Moreover, in Example 4, when the both terminals are pressed by performing gold plating on the trapezoidal terminal and nickel plating on the rectangular terminal, the gold plating layer formed on the surface of the trapezoidal terminal and the nickel plating layer of the rectangular terminal Are crushed to each other, and the contact area is further expanded and firmly connected. Therefore, the connection body 1 can further ensure good electrical conductivity between the first and second electrode terminals 5 and 6.

DESCRIPTION OF SYMBOLS 1 Connection body, 2 Printed wiring board, 3 Flexible board, 4 Adhesive, 4a Insulating adhesive film, 5 1st electrode terminal, 5a Corner | angular part, 6 2nd electrode terminal, 7 Connection part, 8 Terminal area | region 10 Guide surface, 11 release film, 12 binder resin layer, 13 take-up reel, 20 first plating layer, 21 second plating layer

Claims (11)

In the manufacturing method of the connection body in which the electrode terminal of the first circuit member and the electrode terminal of the second circuit member are connected,
By fitting one second electrode terminal formed on the second circuit member between a pair of first electrode terminals formed on the first circuit member, the first and second Forming one connection between the two electrode terminals;
A method of manufacturing a connection body in which at least one of the first and second electrode terminals slides on the other electrode terminal to form a guide surface for aligning the first and second electrode terminals. .   The method for manufacturing a connection body according to claim 1, wherein at least one of the first and second electrode terminals is formed in a trapezoidal cross section having a pair of tapered surfaces as the guide surface. The guide surface is formed on one of the first and second electrode terminals,
3. The method for manufacturing a connection body according to claim 1, wherein the other of the first and second electrode terminals is formed in a rectangular cross section. The guide surface is formed on one of the first and second electrode terminals,
3. The method for manufacturing a connection body according to claim 1, wherein the other of the first and second electrode terminals is formed with a guide surface having an angle different from that of the guide surface formed on the one electrode terminal.   The said 1st and / or 2nd electrode terminal in which the said guide surface was formed is a manufacturing method of the connection body of any one of Claims 1-4 currently formed by the etching method.   4. The method of manufacturing a connection body according to claim 3, wherein the other of the first and second electrode terminals is formed in a rectangular cross section by an additive method.   The method for manufacturing a connection body according to any one of claims 1 to 6, wherein at least one of the first and second electrode terminals is copper or metal wiring mainly composed of copper. One of the first and second electrode terminals is an electrode obtained by performing gold plating on copper or a metal wiring mainly composed of copper,
The connection according to any one of claims 1 to 6, wherein the other of the first and second electrode terminals is an aluminum electrode or an electrode obtained by performing aluminum plating on a metal wiring mainly composed of copper or copper. Body manufacturing method.   The manufacturing method of the connection body of any one of Claims 1-8 which connects a 1st circuit member and a said 2nd circuit member with an insulating adhesive film or an insulating adhesive paste. In the circuit member connection method of connecting the electrode terminal of the first circuit member and the electrode terminal of the second circuit member with an adhesive,
By fitting one second electrode terminal formed on the second circuit member between a pair of first electrode terminals formed on the first circuit member, the first and second Forming one connection between two electrode terminals,
A circuit member connection method in which at least one of the first and second electrode terminals slides on the other electrode terminal to form a guide surface for aligning the first and second electrode terminals. .   The connection body manufactured by the method of any one of the said Claims 1-9.

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