JP2013207115A - Connection structure and manufacturing method of the same, electronic component and manufacturing method of the same, connection method of electronic component - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a short circuit between adjacent connection terminals.SOLUTION: A connection structure includes an electronic components 1, 2 which have a plurality of connection terminals 6, 7 and are connected at the connection terminals 6, 7 via a conductive adhesive 3 to each other. In at least the electronic components 1, an insulative structure 20 is formed between adjacent connection terminals 6, 6. The insulative structure 20 is formed so that its upper part width is smaller than its bottom part width in a sectional view.

Description

  The present invention relates to a connection structure in which electronic components in which a plurality of connection terminals are arranged are connected to each other via a conductive adhesive, a manufacturing method thereof, an electronic component in which a plurality of connection terminals are arranged, and The present invention relates to a manufacturing method and a method for connecting electronic components that connect electronic components in which a plurality of connection terminals are arranged.

  Conventionally, when connecting a rigid substrate such as a glass substrate or a glass epoxy substrate and a flexible substrate, or connecting flexible substrates, an anisotropic conductive adhesive in which conductive particles are dispersed in a binder resin is used. It has been. When connecting the connection terminal of the flexible substrate and the connection terminal of the rigid substrate, an anisotropic conductive adhesive is disposed between the regions where the connection terminals of both the substrates are formed, and heat-pressed. Then, the binder resin exhibits fluidity and flows out from between the connection terminal of the flexible substrate and the connection terminal of the rigid substrate, and the conductive particles in the anisotropic conductive adhesive are sandwiched between the connection terminals. It is crushed.

  As a result, the connection terminal of the flexible substrate and the connection terminal of the rigid substrate are electrically connected via the conductive particles, and the binder resin is cured in this state. The conductive particles that are not between the two connection terminals are dispersed in the binder resin and maintain an electrically insulated state. Thereby, electrical conduction is achieved only between the connection terminal of the flexible substrate and the connection terminal of the rigid substrate.

Japanese Patent Laid-Open No. 11-282002 JP 2000-323523 A

  By the way, in the connection method using an anisotropic conductive adhesive, if the distribution and terminal height of the terminals formed in the heat and pressure region vary, the pressure applied to the connection terminals becomes non-uniform, resulting in insufficient pressure. Conductive particles may be crushed too much due to poor conduction or excessive pressure.

  As shown in FIG. 12 (a), when the conductive particles 52 are excessively crushed when the conductive particles 52 are sandwiched between the connection terminals 50 and 51 of the opposing substrates, the thermal pressurization process is completed. When the binder resin 53 in the connection region expands and the connection terminals 50 and 51 are separated due to subsequent environmental changes such as temperature and humidity, and aging of the connection structure between the substrates, FIG. As shown in FIG. 2, there is a risk that the conductive particles 52 lose the elasticity to follow the separation between the connection terminals 50 and 51 and cause poor conduction. In addition, when the conductive particles 52 are pushed in until they are crushed, the binder resin 52 between the connection terminals 50 and 51 is also insufficient, and the connection reliability is poor.

  In addition, if the distribution and terminal height of the terminals formed in the thermal pressurization area vary, the substrate may be warped during the thermal pressurization process, resulting in dangers such as damage to the wiring pattern and peeling between connection terminals. There is also.

  Therefore, conventionally, in order to prevent such inconvenience, a method of providing dummy bumps that do not contribute to conduction on a substrate and a method of blending large-diameter spacer particles in an anisotropic conductive adhesive are employed (for example, patents). Reference 1 and Patent Reference 2).

  However, when rectangular dummy bumps 54 are provided as shown in FIG. 13 (a), conductive particles 52 are arranged on the dummy bumps 54 as shown in FIG. There is a risk of short-circuiting between adjacent connection terminals 51 and 51.

  In addition, when large-diameter spacer particles are blended in the anisotropic conductive adhesive, if the spacer particles are sandwiched between the connecting terminals of the opposing substrates, variations in height and warping of the substrate are eliminated. I couldn't.

  Then, an object of this invention is to provide the connection structure which can prevent the short circuit between adjacent connection terminals, its manufacturing method, an electronic component, its manufacturing method, and the connection method of an electronic component. Another object of the present invention is to provide a connection structure that can prevent the conductive particles from being crushed, a method for manufacturing the connection structure, an electronic component, a method for manufacturing the electronic component, and a method for connecting the electronic component.

  In order to solve the above-described problems, a connection structure according to the present invention is a connection structure in which electronic components in which a plurality of connection terminals are arranged are connected to each other via a conductive adhesive. In at least one of the electronic components, an insulating structure is formed between the adjacent connection terminals, and the insulating structure is formed such that the top width is narrower than the bottom width in a sectional view. is there.

  Moreover, in the method for manufacturing a connection structure according to the present invention, the electronic components in which a plurality of connection terminals are arranged are connected to each other via the conductive adhesive. Between the connection terminals adjacent to each other at least one electronic component, an insulating structure is formed in which the upper width is narrower than the bottom width in a cross-sectional view, and the electronic components are connected to each other via the adhesive. The connection terminals are opposed to each other and pressed, and the adhesive is cured to be electrically and mechanically connected.

  The electronic component according to the present invention is formed between a plurality of adjacent connection terminals and a plurality of adjacent connection terminals, and has an upper width narrower than a bottom width in a cross-sectional view. The connection terminal is connected to a connection terminal formed on another electronic component via a conductive adhesive.

  In the electronic component manufacturing method according to the present invention, a plurality of connection terminals arranged adjacent to each other are formed, and an upper width is formed narrower than a bottom width in a sectional view between the plurality of adjacent connection terminals. Insulating structures are formed.

  Moreover, the connection method of the electronic component which concerns on this invention is the connection method which connects the electronic components with which the several connection terminal was arranged through the conductive adhesive, The said connection terminal which at least one electronic component adjoins. In the meantime, an insulating structure having an upper width narrower than a bottom width in a cross-sectional view is formed, and the electronic parts are pressed with the connection terminals facing each other via the adhesive. The adhesive is cured and electrically and mechanically connected.

  According to the present invention, the insulating structure has a shape in which the top width is narrower than the bottom width in a cross-sectional view, and is thermally pressed from above through the electronic component, so that the conductive particles near the top are formed on the top. Along the left and right sides. Thereby, the insulating structure can prevent a conductive particle from continuing between adjacent connection terminals, and can prevent the short circuit between connection terminals.

  Moreover, according to this invention, an insulating structure functions as a stopper which controls the connection thickness of electronic components, and it can prevent that a conductive particle is crushed too much by connection terminals.

It is a disassembled perspective view which shows the connection structure of the printed wiring board and flexible substrate to which this invention was applied. It is a disassembled perspective view which shows the connection state in the FOB mounting part of a printed wiring board. It is sectional drawing which shows an anisotropic conductive film. It is sectional drawing which shows the process of connecting the printed wiring board in which the insulating structure was formed via ACF, and a flexible substrate, (a) shows before heat press, (b) shows after heat press. Show. It is sectional drawing which shows the printed wiring board provided with the triangular-shaped insulating structure, and a flexible substrate. It is sectional drawing which shows the printed wiring board provided with the trapezoid insulating structure, and a flexible substrate. In the connection structure to which the present invention is applied, the printed wiring board and the flexible substrate are separated from each other after connection. It is a perspective view which shows the process of forming a soldering resist layer in a printed wiring board. It is a side view which shows the process of forming a semicircular insulating structure. It is a side view which shows the process of forming a triangular-shaped insulating structure. It is a side view which shows the process of forming a trapezoidal insulating structure. It is sectional drawing which shows the conventional connection structure in which the electroconductive particle was crushed too much, (a) is the state immediately after the connection, (b) shows the state which the separation between the connection terminals produced by expansion | swelling of binder resin. It is sectional drawing which shows the conventional connection structure in which the dummy bump was formed, (a) is the state before thermal pressurization, (b) shows the state which the electroconductive particle continued on the dummy bump and the short circuit occurred by thermal pressurization.

  Hereinafter, a connection structure to which the present invention is applied, a method for manufacturing the same, an electronic component, a method for manufacturing the electronic component, and a method for connecting the electronic component 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.

[Printed wiring board]
The connection structure to which the present invention is applied is a connection structure in which a flexible substrate and a rigid substrate are connected in an anisotropic conductive manner, or a connection structure in which flexible substrates are connected in an anisotropic conductive manner. It can be used for printed wiring boards incorporated in all electronic devices such as PCs, mobile phones, game machines, audio devices, tablet terminals, and in-vehicle monitors. In such a printed wiring board, a so-called FOB (film on board) in which a flexible substrate on which various circuits are formed is directly mounted on the printed wiring board is adopted from the viewpoints of fine pitch, light weight and thinning. .

  As shown in FIG. 1, the printed wiring board 1 is formed with various wiring patterns and various components such as an IC chip, and a flexible substrate 2 is formed of an anisotropic conductive film (ACF) 3. The connection structure is configured by being connected via the.

  In the printed wiring board 1, a plurality of terminal portions 6 connected to connection terminals 7 provided on the flexible substrate 2 are formed in the FOB mounting portion 5 to which the flexible substrate 2 is connected. As shown in FIG. 2, the terminal portion 6 is formed in, for example, a substantially rectangular shape, and is formed by arranging a plurality of terminals over a direction orthogonal to the longitudinal direction.

  The FOB mounting portion 5 is connected to the flexible substrate 2 using an anisotropic conductive film 3 as a conductive adhesive. As will be described later, the anisotropic conductive film 3 contains conductive particles in a binder resin, and the conductive terminals include the connection terminals 7 of the flexible substrate 2 and the terminal portions 6 formed on the printed wiring board 1. Electrical connection via

[Flexible substrate]
As shown in FIG. 2, the flexible substrate 2 connected to the FOB mounting portion 5 of the printed wiring board 1 has a plurality of connection terminals 7 connected to the terminal portion 6 on a flexible substrate 9 such as polyimide. It is formed in an array. The connection terminal 7 is formed, for example, by patterning a copper foil or the like, and by appropriately performing a plating coating process such as nickel gold plating on the surface. A plurality are arranged in a direction orthogonal to the longitudinal direction.

[Anisotropic conductive film]
The anisotropic conductive film 3 is a thermosetting or ultraviolet curable adhesive, which is fluidized by heat and pressure applied by a heating and pressing head (not shown) so that the conductive particles become the terminal portion 6 and the flexible substrate. It is crushed between the two connection terminals 7 and cured in a state where the conductive particles are crushed by heating or ultraviolet irradiation. Thereby, the anisotropic conductive film 3 electrically and mechanically connects the printed wiring board 1 and the flexible substrate 2.

  For example, as shown in FIG. 3, the anisotropic conductive film 3 is conductive to a normal binder resin 8 (adhesive) containing a film-forming resin, a thermosetting resin, a latent curing agent, a silane coupling agent, and the like. The particles 9 are dispersed, and the thermosetting adhesive composition is applied onto the base film 10 to be formed into a film shape.

  The base film 10 is formed, for example, by applying a release agent such as silicone to PET (Poly Ethylene Terephthalate), OPP (Oriented Polypropylene), PMP (Poly-4-methlpentene-1), PTFE (Polytetrafluoroethylene), or the like.

  The film forming resin contained in the binder resin 8 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.

  Examples of the conductive particles 9 include any known conductive particles used in the anisotropic conductive film 3. Examples of the conductive particles 9 include particles of various metals and metal alloys such as nickel, iron, copper, aluminum, tin, lead, chromium, cobalt, silver, gold, metal oxide, carbon, graphite, glass, ceramic, Examples thereof include those in which the surface of particles such as plastic is coated with metal, or those in which the surface of these particles is further coated with an insulating thin film. In the case where the surface of the resin particle is coated with metal, examples of the resin particle include an epoxy resin, a phenol resin, an acrylic resin, an acrylonitrile / styrene (AS) resin, a benzoguanamine resin, a divinylbenzene resin, a styrene resin, and the like. Can be mentioned.

  In addition, the anisotropic conductive film 3 is good also as a structure which provides a cover film in the surface opposite to the surface where the base film 10 was laminated | stacked from viewpoints of the ease of handling, storage stability, etc. The shape of the anisotropic conductive film 3 is not particularly limited. For example, as shown in FIG. 3, the anisotropic conductive film 3 has a long tape shape that can be wound around the take-up reel 12, and is cut by a predetermined length. can do.

  Moreover, although the above-mentioned embodiment demonstrated as an example the adhesive film which shape | molded the thermosetting resin composition which contained the electroconductive particle 9 in the binder resin 8 suitably as an adhesive agent, it concerns on this invention. An adhesive agent is not limited to this, For example, it can be set as the structure which laminated | stacked the insulating adhesive layer which consists only of binder resin 8, and the electroconductive particle content layer which consists of binder resin 8 containing the electroconductive particle 9. FIG. . Moreover, an adhesive agent is not limited to the electroconductive adhesive film formed by such a film formation, It is good also as an electroconductive adhesive paste by which the electroconductive particle 9 was disperse | distributed to the binder resin composition. The adhesive according to the present invention includes any of the forms described above.

[Insulating structure]
As shown in FIG. 4, the printed wiring board 1 to which the present invention is applied is provided with an insulating structure 20 between adjacent terminal portions 6. The insulating structure 20 is made of, for example, a solder resist, and has a shape in which the top width is narrower than the bottom width in a sectional view, for example, a hemispherical shape shown in FIG. 4A, a triangular shape shown in FIG. 5, or a trapezoidal shape shown in FIG. Make. Moreover, the insulating structure 20 is continuously formed along the formation direction of the connection terminal 7 as shown in FIG.

  The insulating structure 20 prevents a short circuit between adjacent terminal portions 6 and 6 of the printed wiring board 1 or between adjacent connection terminals 7 and 7 of the printed wiring board 1. That is, as shown in FIG. 4B, the insulating structure 20 is flexible when the flexible substrate 2 is connected to the printed wiring board 1 through the anisotropic conductive film 3 by being hot-pressed. The top portion 20 a is positioned between the connection terminals 7 and 7 adjacent to each other on the substrate 2. Further, the insulating structure 20 has a shape in which the top width is narrower than the bottom width in a cross-sectional view, and is thermally pressed from above through the flexible substrate 2, whereby the conductive particles 9 near the top 20a are Separating left and right along the shape of 20a. Thereby, the insulating structure 20 can prevent a conductive particle from continuing between the adjacent terminal parts 6 and 6 or between the adjacent connection terminals 7 and 7, and between the terminal parts 6 and 6 or the connection terminal. 7 and 7 can be prevented from being short-circuited.

  Moreover, it is preferable that the insulating structure 20 has a height higher than the total height of the opposing printed wiring board 1, the terminal portion 6 of the flexible substrate 2, and the connection terminal 7. Thereby, the insulating structure 20 functions as a stopper for regulating the connection thickness between the printed wiring board 1 and the flexible substrate 2, and prevents the conductive particles 9 from being crushed too much by the terminal portions 6 and the connection terminals 7. Can do.

  That is, as shown in FIG. 7A, the insulating structure 20 has a height H3 higher than the total height of the height H1 of the terminal portion 6 and the height H2 of the connection terminal 7 (H1 + H2 <H3). ), When the flexible substrate 2 is thermally pressed to the printed wiring board 1, the distance between the terminal portion 6 and the connection terminal 7 is regulated by the insulating structure 20. As a result, the pressing force of the heating and pressing head can be reduced due to variations in the height of the terminal portion 6 and the connection terminal 7 in the FOB mounting portion 5, the surface accuracy of the heating and pressing surface of the heating and pressing head, or the thickness tolerance of the buffer material. Even when variations occur, it is possible to prevent the conductive particles 9 from being crushed too much due to excessive pressure.

  Accordingly, the connection structure between the printed wiring board 1 and the flexible substrate 2 is, as shown in FIG. 7B, an environmental change such as temperature and humidity after the end of the thermal pressurization process, or a connection structure between the substrates. Even when the binder resin 8 in the connection region expands due to secular change or the like, and the terminal portion 6 and the connection terminal 7 are separated from each other, the conductive particles 9 do not lose elasticity, and the terminal portion 6 and the connection terminal 7 Follow the separation. Thereby, this connection structure can prevent the conduction | electrical_connection defect of the terminal part 6 and the connection terminal 7. FIG.

  Moreover, since the connection structure of the printed wiring board 1 and the flexible substrate 2 is not pushed in until the conductive particles 9 are crushed too much, the binder resin 8 between the terminal portion 6 and the connection terminal 7 is also insufficient. Connection reliability can be maintained.

  Furthermore, the insulating structure 20 is preferably made lower than the height obtained by adding the average particle diameter of the conductive particles 9 to the heights of the terminal portion 6 and the connection terminal 7. Thereby, the insulating structure 20 can prevent the situation where the height becomes too high and the conductive particles 9 cannot be held between the terminal portion 6 and the connection terminal 7.

  The insulating structure 20 may be formed in a region between all the terminal portions 6 and 6 formed in the FOB mounting portion 5 of the printed wiring board 1, but in particular, the printed wiring board 1 and the flexible substrate 2. Of the terminal portion 6, for example, only in the region between the terminal portions 6, 6 formed at both ends of the plurality of arranged terminal portions 6, or when the terminal portion 6 is dense or dense. You may make it form only in a sparse area | region.

  Moreover, the insulating structure 20 may be formed on the flexible substrate 2 side in addition to being formed only on the printed wiring board 1 side. In this case, it may be formed on one of the printed wiring board 1 and the flexible substrate 2, may be formed on both, and the insulating structures 20 formed so as to face each other may be abutted, or terminals. You may form alternately between the parts 6 and 6 and between the connection terminals 7 and 7. FIG.

[Insulating structure manufacturing method]
Next, a process for forming the insulating structure 20 will be described. The insulating structure 20 is formed using an insulating photocurable resin such as a solder resist, and as shown in FIG. 8, a circuit pattern is formed on the printed wiring board 1 on which the terminal portion 6 and other wiring patterns are formed. It can form in the same process as the process of forming the soldering resist used as the insulating film which protects. Further, the insulating structure 20 can be formed simultaneously in the process of forming a solder resist film for protecting the circuit pattern on the printed wiring board 1.

  Specifically, as shown in FIG. 8A, terminal portions 6 and other wiring patterns are formed on the printed wiring board 1 by a known method. Next, as shown in FIG. 8B, a liquid solder resist 30 is applied over the entire surface of the printed wiring board 1, and precure is performed. Precure is performed by heating the printed wiring board 1 coated with the liquid solder resist, for example, with heat of 80 ° C. for about 20 to 30 minutes, and then drying.

  Next, as shown in FIG. 8C, exposure is performed. The exposure is performed by irradiating the printed wiring board 1 with light rays such as ultraviolet rays through a mask (negative film) 31. The solder resist 30 is hardened in the portion exposed to the ultraviolet rays. Thereafter, development is performed as shown in FIG. The development is performed by etching and washing away the uncured solder resist 30 with a developer such as a dilute alkaline aqueous solution. Finally, post cure is performed. Post-cure heats the printed wiring board 1 with, for example, 150 ° C. for about 50 to 60 minutes to completely cure the solder resist 30 remaining on the printed wiring board 1, thereby forming a pattern of the solder resist 30. Complete.

  Here, as shown in FIG. 9, the semicircular insulating structure 20 in a cross-sectional view has a distance between the terminal portions 6, 6 after the uncured liquid solder resist 30 is applied between the terminal portions 6, 6. After performing a curing process using ultraviolet light incident in parallel through a mask having an opening having a width of 80% or less, etching is performed for a development time longer than the recommended development time by 50% or more. As a result, since the development time of the insulating structure 20 is longer than usual, a part of the exposed portion is also eroded by the developer, and as a result, both corners of the upper surface are taken in a sectional view and finished in a semicircular cross section. .

  Further, as shown in FIG. 10, the insulating structure 20 having a triangular shape in a cross-sectional view has an uncured liquid solder resist 30 applied between the terminal portions 6 and 6, and then 10% of the distance between the terminal portions 6 and 6. It forms by etching, after performing the hardening process with the ultraviolet light L by diffused light through the mask 31 which has the opening part 32 of the following width | variety. As a result, the insulating structure 20 is finished in a triangular shape in sectional view because the opening 32 of the mask 31 is narrow and diffused light is used.

  In addition, as shown in FIG. 11, the semi-circular insulating structure 20 in cross-sectional view is obtained by applying an uncured liquid solder resist 30 between the terminal portions 6 and 6 and then a distance 50 between the terminal portions 6 and 6. After performing a curing process using ultraviolet light L incident in parallel through a mask 31 having an opening 32 having a width of not more than%, etching is performed in a developing time shorter than 50% by the recommended developing time. As a result, the insulating structure 20 has a narrow upper surface because the opening 32 of the mask 31 is slightly narrow. Further, since the insulating structure 20 has a shorter development time than usual, the lower part is less likely to be removed than usual. As a result, the insulating structure 20 is finished in a trapezoidal shape in a cross-sectional view.

  As described above, the insulating structure 20 has a desired shape depending on the light source selection (parallel light or diffused light) at the time of curing by light irradiation, the size of the opening of the mask, and the strength of development processing (development time, etc.). Can be formed.

  The anisotropic conductive film 3 is temporarily attached to the FOG mounting portion 5 on the printed wiring board 1 on which the insulating structure 20 is formed. The anisotropic conductive film 3 has the surface on which the binder resin 8 is formed adhered to the FOG mounting portion 5, and the binder resin 8 exhibits fluidity from the top of the base film 10 by a heating and pressing head, but starts thermosetting. This is done by heat-pressing at a low pressure and in a short time at a temperature that does not.

  Next, the flexible substrate 2 is placed on the FOB mounting portion 5 on which the anisotropic conductive film 3 is temporarily attached. At this time, the flexible substrate 2 is subjected to alignment adjustment so that the connection terminal 7 is placed on the predetermined terminal portion 6. And it heat-presses for a predetermined | prescribed pressure and predetermined | prescribed time from the flexible substrate 2 with the heating press head heated to the curing temperature of the binder resin 8. FIG. Thereby, in the anisotropic conductive film 3, the binder resin 8 is fluidized and flows out from between the terminal portion 6 and the connection terminal 7, and the conductive particles 9 are sandwiched between the terminal portion 6 and the connection terminal 7. It hardens in this state. Thereby, a connection structure in which the printed wiring board 1 and the flexible substrate 2 are electrically and mechanically connected is manufactured.

  In the above description, the case where the flexible substrate 2 is connected to the printed wiring board 1 as the connection structure has been described as an example. However, the present invention is not limited to the FOB mounting, and the insulating structure is not limited to at least one electronic component connected to each other by ACF. The present invention can be applied to a connection structure in which a structure is formed, for example, a connection structure in which flexible substrates are connected to each other, or a connection structure in which an IC chip or the like is mounted on a rigid substrate or a flexible substrate.

  Next, examples of the present invention will be described. In this example, a printed wiring board in which an insulating structure was formed between adjacent terminal portions was prepared, and a connection structure sample in which a flexible substrate was connected to each via an ACF was formed. And about each connection structure sample, the incidence rate of the short circuit between terminal parts was measured.

  The printed wiring board which concerns on an Example and a comparative example used Hitachi Chemical Co., Ltd. product: MCL-E-67. This printed wiring board is an FR-4 grade glass epoxy base material, and Cu wiring of 18 μm thickness plated with Ni / Au is formed at a pitch of 400 μm (L / S = 1/1). .

  The flexible substrate which concerns on an Example and a comparative example used Nippon Steel Chemical Co., Ltd. product: SC12-25-00CE. In this flexible substrate, Cu wiring having a thickness of 12 μm on which a Ni / Au plating is applied is formed on a polyimide substrate at a pitch of 400 μm (L / S = 1/1).

The insulating structure formed on the printed wiring board according to the example and the comparative example uses a solder resist manufactured by Taiyo Ink Manufacturing Co., Ltd .: PSR-4000 BL01, and has a predetermined shape by an etching process by photolithography shown in FIG. Formed. In addition, as an exposure device, the collimated light used: Oak Manufacturing Co., Ltd .: EXM-1201, and the diffused light used: Oak Manufacturing Co., Ltd .: HMW-680. The exposure amount is 300 mJ / cm ² in all cases. Further, a Ritter spray machine manufactured by Yamagata Machinery Co., Ltd. was used as a developing machine. The developer was sprayed with a 1 mass% sodium carbonate aqueous solution at 30 ° C. at a spray pressure of 0.2 MPa.

  In Example 1, a printed wiring board on which a semicircular insulating structure was formed in a cross-sectional view was used. The insulating structure according to Example 1 has a height A of 40 μm, a top width B of 0 μm, and a bottom width C of 120 μm.

  In Example 2, a printed wiring board having a triangular insulating structure formed in a cross-sectional view was used. The insulating structure according to Example 2 has a height A of 40 μm, a top width B of 0 μm, and a bottom width C of 120 μm.

  In Example 3, a printed wiring board in which a trapezoidal insulating structure was formed in a cross-sectional view was used. The insulating structure according to Example 3 has a height A of 40 μm, a top width B of 100 μm, and a bottom width C of 120 μm.

  In Comparative Example 1, a printed wiring board on which a rectangular insulating structure was formed in a sectional view was used. The insulating structure according to Example 1 has a height A of 40 μm, a top width B of 120 μm, and a bottom width C of 120 μm.

  As shown in Table 1, in Examples 1 to 3 having an insulating structure in which the top width is narrower than the bottom width in a cross-sectional view, the occurrence rate of short circuit was 0 to 0.5%. On the other hand, in the comparative example having a rectangular insulating structure in a cross-sectional view, the short-circuit occurrence rate was 1%.

  In this embodiment, since the top width is narrower than the bottom width in cross-sectional view, the conductive particles near the top are formed into the shape of the top by being heat-pressed from above via a flexible substrate. This is because the conductive particles can be prevented from being continuous between the adjacent terminal portions or between the adjacent connection terminals.

  On the other hand, in the comparative example, conductive particles continued along the top, and the occurrence rate of short circuit increased.

DESCRIPTION OF SYMBOLS 1 Printed wiring board, 2 Flexible substrate, 3 Anisotropic conductive film, 5 FOB mounting part, 6 Terminal part, 7 Connection terminal, 8 Binder resin, 9 Conductive particle, 10 Base film, 12 Take-up reel, 20 Insulation Structure, 20a top, 30 solder resist, 31 mask, 32 opening

Claims (19)

In the connection structure in which the connection parts are connected to each other through a conductive adhesive between the electronic components in which a plurality of connection terminals are arranged,
In at least one electronic component, an insulating structure is formed between the adjacent connection terminals,
The insulating structure is a connection structure in which an upper width is narrower than a bottom width in a cross-sectional view.   The insulating structure is higher than the total height of both connection terminals of the opposing electronic components, and the average particle diameter of the conductive particles contained in the total height of both connection terminals and the conductive adhesive The connection structure according to claim 1, wherein the connection structure is lower than a height obtained by adding together.   The connection structure according to claim 1, wherein the insulating structure has a triangular shape in a cross-sectional view.   The connection structure according to claim 1, wherein the insulating structure has a trapezoidal shape in a cross-sectional view.   The connection structure according to claim 1, wherein the insulating structure has a semicircular shape in a cross-sectional view.   The connection structure according to claim 1 or 2, wherein the insulating structure is formed between the connection terminals formed at an end portion of a terminal region in which the plurality of connection terminals are arranged.   The connection structure according to claim 1, wherein the insulating structure is formed between all the connection terminals formed in a terminal region in which a plurality of the connection terminals are arranged. In the manufacturing method of the connection structure in which the electronic components in which the plurality of connection terminals are arranged are connected to each other via the conductive adhesive,
Between the adjacent connection terminals of at least one electronic component, an insulating structure is formed in which the top width is narrower than the bottom width in cross-sectional view,
A manufacturing method of a connection structure in which the electronic components are pressed against each other with the connection terminals facing each other via the conductive adhesive, and the adhesive is cured to be electrically and mechanically connected.   The method for manufacturing a connection structure according to claim 8, wherein the insulating structure is formed using a photocurable resin.   The insulating structure is obtained by applying an uncured photocurable resin between the connection terminals and then performing a curing process with light through a mask having an opening having a width of 80% or less of the distance between the connection terminals. The method for producing a connection structure according to claim 9, wherein the connection structure is formed by etching at a development time longer than 50% by a recommended development time.   The insulating structure was subjected to curing treatment with diffused light through a mask having an opening having a width of 10% or less of the distance between the connection terminals after applying an uncured photocurable resin between the connection terminals. The method for manufacturing a connection structure according to claim 9, wherein the connection structure is formed by performing etching later.   The insulating structure is obtained by applying an uncured photocurable resin between the connection terminals and then performing a curing process with light through a mask having an opening having a width of 50% or less of the distance between the connection terminals. The method for producing a connection structure according to claim 9, wherein the connection structure is formed by etching at a development time of 50% or less from the recommended development time. A plurality of connection terminals arranged adjacent to each other;
An insulating structure formed between a plurality of adjacent connection terminals, the upper width being narrower than the bottom width in a cross-sectional view,
An electronic component in which the connection terminal is connected to a connection terminal formed on another electronic component via a conductive adhesive. Forming a plurality of connection terminals arranged adjacent to each other;
An electronic component manufacturing method for forming an insulating structure in which an upper width is narrower than a bottom width in a cross-sectional view between a plurality of adjacent connection terminals.   The method of manufacturing an electronic component according to claim 14, wherein the insulating structure is formed using a photocurable resin.   The insulating structure is obtained by applying an uncured photocurable resin between the connection terminals and then performing a curing process with light through a mask having an opening having a width of 80% or less of the distance between the connection terminals. The method of manufacturing an electronic component according to claim 15, wherein the electronic component is formed by etching at a development time longer than 50% by a recommended development time.   The insulating structure was subjected to curing treatment with diffused light through a mask having an opening having a width of 10% or less of the distance between the connection terminals after applying an uncured photocurable resin between the connection terminals. The method of manufacturing an electronic component according to claim 15, which is formed by performing etching later.   The insulating structure is obtained by applying an uncured photocurable resin between the connection terminals and then performing a curing process with light through a mask having an opening having a width of 50% or less of the distance between the connection terminals. The method of manufacturing an electronic component according to claim 15, wherein the electronic component is formed by etching with a development time of 50% or less from the recommended development time. In a connection method for connecting electronic components in which a plurality of connection terminals are arranged via a conductive adhesive,
Between the adjacent connection terminals of at least one electronic component, an insulating structure is formed in which the top width is narrower than the bottom width in cross-sectional view,
A method for connecting electronic parts, wherein the electronic parts are pressed with the connection terminals facing each other via the conductive adhesive, and the conductive adhesive is cured and electrically and mechanically connected.

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