JP2007165345A - Thermocompression apparatus of flexible wiring board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thermocompression apparatus of a flexible wiring board where extension of a terminal array direction in a connection terminal string part of the flexible wiring board during heat compression bonding is adjusted, and a conduction connection defect due to thermal expansion of the flexible wiring board does not occur even in conduction bonding with a fine pitch connection terminal string of a mobile apparatus. <P>SOLUTION: In a depression head 7, a pair of depression sheet bunches 72a and 72b overlapped while a plurality of depression sheet boards 721 are erected by inclining them by angles θ and -θ with respect to a pressurizing direction P are arranged on both sides, across a center projection 712 which is protrusively disposed in a center of a surface 7111 turned to the pressurizing direction P of a substrate block 71. The pressurizing sheet bunches 72a and 72b are sandwiched with a pair of holding boards 73 and 73, a pair of holding blocks 74 and 74, and the center projection 712. Pressurizing faces 7a and 7b of the pressurizing sheet bunches 72a and 72b are finished in flat faces by a polishing processing. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a thermocompression bonding apparatus for conductively bonding a flexible wiring board to another circuit board.

  In recent years, an image display module using an image display panel such as a liquid crystal display panel or an organic electroluminescence display panel is advantageous in reducing the size and thickness of the applied device, and in recent years, mobile devices such as a mobile phone and a PDA (Personal Digital Assistance). Is widely used as a display. Since the image display module used as the display of these mobile devices has a small screen size and high definition, the arrangement pitch of the connection terminals of the drive signal supply wiring is highly refined.

  On the other hand, as a wiring member for electrically connecting the image display module of the mobile device and the external drive control circuit board as described above, a flexible wiring board that is advantageous for thinning is often used. An anisotropic conductive adhesive is suitably used as a joining member for conducting and joining the connection terminals having a fine pitch between the flexible wiring board and the image display module with good workability.

  The anisotropic conductive adhesive is obtained by molding a material in which conductive particles having an average particle diameter of about 5 μm are dispersed and mixed in a thermosetting binder resin such as an epoxy resin. In the conductive joining step, the connection terminal row of the flexible wiring board is placed on the connection terminal row of the image display module while aligning the connection terminal row of the flexible wiring board via the anisotropic conductive adhesive. The thermocompression bonding head heated to a predetermined temperature is pressed directly or indirectly through a sheet or the like for preventing adhesion of anisotropic conductive adhesive as shown in Patent Document 1, The thermosetting binder resin is cured with the conductive particles sandwiched between the connection terminals, and the connection terminal rows are fixed.

JP 9-162544 A

  In the above-described conductive bonding process, the connection terminal row portion of the flexible wiring board is heated and expands to cause expansion in the connection terminal juxtaposition direction (hereinafter referred to as the terminal array direction). Deviation occurs. In conductive joining between an image display module of a mobile device with a fine connection terminal array and a flexible wiring board, the displacement of the connection terminals due to thermal expansion of the flexible wiring board is more likely to cause poor conduction connection.

  The object of the present invention is to adjust the extension in the terminal array direction in the connection terminal row portion of the flexible wiring board during thermocompression bonding, and also due to the thermal expansion of the flexible wiring board in the conductive bonding with the fine pitch connection terminal row of the mobile device. It is an object to provide a thermocompression bonding apparatus for a flexible wiring board that can effectively prevent the occurrence of poor connection.

  In the thermocompression bonding apparatus of the present invention, a plurality of wirings are formed on a circuit board on which a plurality of wirings are formed and first connection terminals of each wiring are arranged in parallel at a first pitch to form a first connection terminal row. And a flexible wiring board in which the second connection terminals of each wiring are arranged in parallel at a second pitch corresponding to the first pitch to form a second connection terminal array, and a thermosetting binder resin is formed. The conductive particles are sandwiched between the first connection terminal and the second connection terminal corresponding to each other by applying pressure while heating through an anisotropic conductive adhesive in which conductive particles are dispersed and mixed. A thermocompression bonding apparatus for a flexible wiring board for conductively connecting both connection terminals, wherein the surface of the connection terminal array portion of the flexible wiring board on which the second connection terminal array is formed is formed. Is added while heating the back of the opposite side The pressing head is configured such that a plurality of thin plate materials made of a highly heat-conductive elastic material are stacked while being inclined with respect to the pressing direction, and the front end surface of the bundle of thin plate materials stacked at the same angle. Formed a pressing surface, the pressing surface on the back side of the connection terminal row portion of the flexible wiring board, the overlapping direction of the thin plate material along the parallel arrangement direction of the second connection terminals, It is characterized by direct contact.

  According to the thermocompression bonding apparatus for a flexible wiring board of the present invention, the front end surface of a bundle of thin plate members made of a plurality of highly thermally conductive elastic materials, which are inclined at the same angle with respect to the pressing direction, Since the pressing surface is brought into direct contact with the connection terminal row portion of the flexible wiring board, the component force of the pressing force acts in accordance with the inclination angle of the thin plate material in the direction parallel to the back surface of the connection terminal row portion with which the front end surface comes into contact. And this component force suppresses or promotes the expansion | extension by the heating of the connection terminal row | line | column part in a flexible wiring board. As a result, the flexible wiring that is adjusted in the amount of expansion in the terminal array direction due to thermal expansion of the connection terminal row portion of the flexible wiring board during thermocompression bonding and is conductively bonded by thermocompression bonding using an anisotropic conductive adhesive Even if the corresponding connection terminals of the circuit board and the circuit board are fine pitched, the conductive connection is always ensured.

  In the thermocompression bonding apparatus for a flexible wiring board according to the present invention, when the second pitch is constant over the entire second connection terminal row, the thin plate members have the same size on the opposite sides with respect to the pressing direction. It is preferable that the front end surfaces of the pair of bundles of thin plate members that are inclined at an angle form a pair of pressing surfaces, and are constant throughout the second connection terminal row. When the second pitch is the same as the first pitch of the first connection terminal row, the pair of bundles of the thin plate members are inclined with their respective tip portions approaching each other toward the pressure tip side. It is more preferable to have a configuration. Accordingly, the corresponding connection terminals of the first connection terminal row and the second connection terminal row arranged in parallel at the same constant pitch can be reliably connected to each other without being shifted over the entire row.

  Further, when the second pitch, which is constant over the entire second connection terminal row, is reduced at a predetermined ratio with respect to the first pitch of the first connection terminal row, a pair of bundles of the thin plate members is It is preferable that the respective tip portions are inclined to be spaced apart from each other toward the pressure tip side, and the pressure head configured in this way has a rate of extension due to thermal expansion of the second connection terminal row. It is used in the case where it is smaller than expected, and it is promoted until it reaches a ratio where the extension of the second connection terminal row is expected, and the corresponding connection terminals can be reliably connected to each other throughout the row.

Furthermore, in the thermocompression bonding apparatus for a flexible wiring board of the present invention, as the thin plate material, a thickness t is:
5μm ≦ t ≦ 500μm
It is preferable to use a metal plate of this type, so that the anisotropic conductive adhesive can be heated via the flexible wiring board without lowering the thermal efficiency, and the tip part bends when the pressure is applied, and the flexible wiring board is stretched. The adjustment force, that is, the component force parallel to the contact surface with the flexible wiring board is amplified, and a more effective adjustment effect for elongation can be obtained.

Furthermore, in the thermocompression bonding apparatus for a flexible wiring board of the present invention, the inclination angle θ of the thin plate material is
1 ° ≦ θ ≦ 30 °
It is preferable that both the necessary and sufficient pressing conduction effect and the extension adjusting effect are obtained with respect to the flexible wiring board.

  In addition, the present invention is preferably applied to the case where the circuit board on which the first connection terminal is disposed is one substrate of a liquid crystal display panel in which liquid crystal is sandwiched between a pair of substrates. Even for connection terminals with a fine pitch on a liquid crystal display panel, the corresponding connection terminals of the flexible wiring board can always be connected with high precision and accuracy by thermocompression bonding using an anisotropic conductive adhesive. .

  FIG. 1 is a perspective view showing a liquid crystal display module manufactured by a thermocompression bonding apparatus as an embodiment of the present invention, and FIG. 2A is a side view showing the thermocompression bonding apparatus and the manufacturing process thereby. FIG. 3B is a plan view showing the thermocompression bonding portion, FIG. 3A is a plan view showing the front end surface of the pressing head in the thermocompression bonding apparatus of this embodiment, and FIG. 3B is a thermocompression bonding state by the pressing head. FIG. 4C is a schematic enlarged sectional view, FIG. 4C is a partial explanatory view showing the Q portion in FIG. 4B in an enlarged manner, and FIGS. 4A to 4D are assembly procedures of the pressing head of the present embodiment. It is explanatory drawing according to the stage which shows.

  As shown in FIG. 1, the liquid crystal display panel 1 in the liquid crystal display module manufactured by the thermocompression bonding apparatus of this embodiment includes a pair of rectangular glass substrates 11 and 12 on which electrodes (not shown) are formed. Each electrode formation surface is made to oppose and it joins with a frame-shaped sealing material (not shown) maintaining a predetermined gap, and each opposing surface (henceforth inner surface) of the glass substrates 11 and 12 enclosed by the frame-shaped sealing material. A liquid crystal (not shown) is enclosed between them. A front polarizing plate 13 and a rear polarizing plate (not shown) are attached to the outer surfaces of the glass substrates 11 and 12, respectively. The liquid crystal display module of the present embodiment is a simple matrix type liquid crystal display module. Each of the opposed inner surfaces of the glass substrates 11 and 12 has a plurality of scanning electrodes (not shown) parallel to each other and orthogonal thereto. A plurality of display electrodes (not shown) parallel to each other are disposed.

  A protruding edge 121 is formed on one glass substrate 12 of the pair of glass substrates 11, 12 with one edge protruding outward from the corresponding edge surface of the glass substrate 11. Lead wires 14a and 14b for supplying a signal voltage to each electrode are provided on the surface (extension surface of the inner surface) of the projecting edge portion 121, and the lead wires provided in the central portion of them. Reference numeral 14a denotes a display lead wiring in which each display electrode is extended. Further, the lead wiring 14b divided and arranged on both sides is a scanning lead wiring, and each terminal electrode (not shown) of the scanning electrode arranged on the opposite substrate 11 and the corresponding scanning lead wiring 14b. Is electrically connected by an inter-substrate conductive member (not shown).

  A driver chip 2 as a liquid crystal driving circuit element is mounted in a substantially central portion of the protruding edge 121 by a COG (Chip On Glass) method. That is, the connection terminals (not shown) of the lead wirings 14a and 14b and the one connection terminal (not shown) of the input wiring 15 for inputting various drive control signals to the driver chip 2 are arranged around the periphery of the mounting area of the driver chip 2. The connection terminal and the corresponding projecting electrode terminal (not shown) of the driver chip are conductively connected by the anisotropic conductive adhesive 3.

  The anisotropic conductive adhesive 3 is obtained by dispersing and mixing conductive particles having an average particle size of about 5 μm in an epoxy resin as a thermosetting binder resin. The anisotropic conductive adhesive 3 is formed on the mounting area. When the thermocompression bonding head heated to a predetermined temperature is brought into pressure contact with the driver chip 2 placed therethrough with a predetermined pressure, the corresponding connection terminal and the protruding electrode terminal are electrically connected with the conductive particles sandwiched therebetween. In this state, the thermosetting resin is cured and fixed.

  As shown in FIG. 2B, the other connection terminals 151 of the input wiring 15 are arranged in parallel at the tip of the protruding edge 121. In these connection terminals 151, connection terminals 411 of the corresponding wiring 41 in the flexible wiring board 4 for wiring connection between the external drive control circuit board (not shown) and the liquid crystal display panel 1 are connected via the anisotropic conductive adhesive 5. Conductive connection.

  As shown in FIG. 3B, this anisotropic conductive adhesive 5 also has an average particle size in the epoxy resin 51 as a thermosetting binder resin, as in the anisotropic conductive adhesive 3 described above. A material in which conductive particles 52 of about 5 μm are dispersed and mixed is formed into an elongated tape shape. As shown in FIG. 2B, the length La of the anisotropic conductive adhesive 5 is determined from the connection terminal row of the liquid crystal display panel 1 and the flexible wiring board 4 to be electrically connected from the viewpoint of bonding workability. The dimension is set to be sufficiently larger than the lengths L1 and L2.

  Here, a thermocompression bonding apparatus for thermocompression bonding the flexible wiring board 4 to the liquid crystal display panel 1 using the anisotropic conductive adhesive 5 will be described.

  As shown in FIG. 2A, the thermocompression bonding apparatus of the present embodiment is roughly a work table 6 on which the liquid crystal display panel 1 as a work is placed, and a press installed so as to be movable up and down. It consists of a head 7. A step 611 is formed on the mounting surface 61 on which the liquid crystal display panel 1 of the work table 6 is mounted, and this step 611 serves as a reference when positioning the liquid crystal display panel 1 as a workpiece.

  As shown in the assembly procedure explanatory diagrams of FIGS. 4A to 4D, the pressing head 7 is overlapped with the base block 71 and the surface of the base block 71 facing the pressing direction P. A pair of pressing sheet bundles 72a and 72b composed of a plurality of pressing sheet plates 721, a pair of holding plates 73 and 73 for supporting each side end surface of the overlapping pressing sheet plate 721 from both sides, and an overlapping pressing sheet plate 721 are provided. It consists of a pair of holding blocks 74 and 74 that are supported from opposite sides in the overlapping direction.

  As shown in FIG. 4A, the base block 71 includes a base part 711 having an elongated rectangular parallelepiped shape, and a center convex part 712 projecting from the center. The base 711 has a built-in heater (not shown).

The center convex portion 712 is a tapered block body having an isosceles trapezoidal cross section, and is projected at the center of the surface 7111 of the base portion 711 in the pressing direction P over the entire width. The magnitude θ of each inclination angle with respect to the normal direction (head pressing direction P) of the base part surface 7111 of the pair of inclined side surfaces 7121 and 7121 of the center convex part 712 is:
1 ° ≦ θ ≦ 30 °
In this range, the optimum angle is set according to the material and thickness of the pressing sheet plate 721 described below, the material of the flexible wiring board 4 as the work, the wiring pitch, and the like.

  On the surface 7111 of the base block 71, as shown in FIG. 4C, a large number of pressing sheet plates 721 are superposed and arranged. These press sheet plates 721 are arranged on both sides of the center convex portion 712 so as to be inclined at the same angle by the same number, thereby forming a pair of press sheet bundles 72a and 72b.

Each pressing sheet plate 721 is made of a highly heat conductive elastic material and has a thickness t of 5 μm ≦ t ≦ 500 μm.
It is formed on a thin sheet plate of the order. As the high thermal conductive elastic material, stainless steel, phosphor bronze for spring, beryllium copper, etc. are preferably used. The pressing sheet plate 721 of this embodiment is formed using a stainless steel thin plate having a thickness of 80 μm.

  Each of the pressing sheet plates 721 arranged to be inclined is arranged on the outermost side of each pressing sheet bundle 72a, 72b with the pair of holding plates 73, 73 on both side end surfaces (in the case where the center convex portion 712 side is the inner side). ) Pressing sheet plates 721a and 721b are held by the pair of holding blocks 74 and 74 toward the center convex portion 712, respectively. The inner end surfaces 741 of the holding blocks 74 and 74 are also formed on end surfaces that are inclined at the same angles as the inclination angles θ and −θ of the corresponding inclined side surface 7121 of the center convex portion 712. As a result, the pressing sheet plates 721 of the pressing sheet bundles 72a and 72b sandwiched between the center convex portion 712 and the pair of holding blocks 74 and 74 arranged opposite to each other are inclined at the same angles θ and −θ, respectively. And bundled in close contact with each other.

  The front end surfaces 7a and 7b facing the pressing direction P of the pressing sheet bundles 72a and 72b serve as pressing surfaces that come into pressure contact with the flexible wiring board 4 as a workpiece, and the pressing surfaces 7a and 7b are the pressed pressing sheet plates 721. Are formed in a continuous manner. The pressing surfaces 7a and 7b in the present embodiment are polished into flat surfaces as shown in FIG. 4 (d). The pressing surfaces 7a and 7b are not limited to flat surfaces. For example, when the hardness of the flexible wiring substrate 4 of the workpiece is large, even if the pressing sheet plates 721 are bundled, the pressing surfaces 7a and 7b may be uneven surfaces. Good.

  A gap 7c is secured between the pressing surfaces 7a and 7b. The width w of the gap 7c should be optimally set according to the amount of bending of the tip portion of each pressing sheet plate 721 generated when the pressing surfaces 7a, 7b are pressed against the flexible wiring board 4 of the workpiece. In this embodiment, it is set to about several μm.

  As shown in FIG. 2B, each pressing surface 7 a, 7 b has a long and narrow rectangle, and its length direction is parallel to the terminal array direction Xt of the flexible wiring board 4. The connection terminal 411 is directly brought into contact with the back surface of the connection terminal row portion in which the connection terminals 411 are arranged in parallel (the surface on which the connection terminal 411 is formed is the front surface). The length Lh (see FIG. 3A) of the pressing surfaces 7a and 7b is the length LH obtained by combining the total length 2Lh and the width w of the gap 7c described above. It is set to be larger than the length La of 5.

  The pressing head 7 of the present embodiment configured as described above is easily assembled according to the procedure shown in FIGS.

  First, as shown in FIG. 4B, a pair of holding plates 73 are attached to both side surfaces of the base block 71 using bolts 75. Next, as shown in FIG. 4C, a predetermined number of pressing sheet plates 721 are arranged in holding spaces S1 and S2 sandwiched between a pair of holding plates 73 on both sides of the center convex portion 712, respectively. After the predetermined number of pressing sheet plates 721 are arranged, the holding blocks 74 are respectively installed at the end portions of the holding spaces S1 and S2. In this case, each holding block 74 is installed so as to be loosened by an appropriate amount in the head length direction Xh (the overlapping direction of the pressing sheet plate 721) by loosening the tightening by the mounting bolt 76, and a predetermined number of pressing sheet plates 721 are attached. After the arrangement, each holding block 74 is moved toward the center convex portion 712, and the pressed sheet bundles 72a and 72b are securely held without rattling. As a result, the pressed sheet bundles 72a and 72b are obtained in which the pressed sheet plates 721 are in close contact with each other and are inclined at the angle θ. Thereafter, as shown in FIG. 4D, the front end surface of each pressing sheet 721 is polished to be aligned with one plane parallel to the base block surface 7111 to form flat pressing surfaces 7a and 7b, respectively. . Thereby, the press head 7 of this embodiment is completed.

  Next, the thermocompression bonding process performed by the thermocompression bonding apparatus of the present embodiment configured as described above will be described.

  As shown in FIG. 2A, first, the liquid crystal display panel 1 on which the driver chip 2 is mounted by the COG method is placed on the work table 6 by performing alignment with the step 611 as a reference.

  Next, as shown in FIG. 2 (b), the anisotropic conductive adhesive 5 is applied to the tip of the protruding edge 121 of the liquid crystal display panel 1 where the connection terminals 151 of the input wiring 15 are arranged in parallel. The length direction is placed parallel to the terminal array direction Xt of the connection terminals 151.

  Next, anisotropic conduction is performed in such an arrangement that one end of the connection terminal 411 of the wiring 41 in the flexible wiring substrate 4 is arranged so that each connection terminal 411 faces the corresponding connection terminal 151 on the liquid crystal display panel 1 side. It is placed on the adhesive 5 while aligning. At the time of this alignment, each alignment mark (not shown) disposed on each of the corresponding side portions of the flexible wiring board 4 and the liquid crystal display panel 1 is aligned while being recognized by a camera or the like. Matching can be performed easily. In the present embodiment, since the step 611 is provided on the work table 6, the other end of the flexible wiring board 4 set on the anisotropic conductive adhesive 5 on the step upper surface 612 (the thermocompression bonding is performed). End portion on the opposite side to the end portion) can be placed, thereby preventing the displacement of the flexible wiring board 4 placed in alignment.

  Under the above-described state, as shown in FIG. 2A, the pressing head 7 that has heated the pressing surfaces 7 a and 7 b to a predetermined temperature is lowered, and the pressing surfaces 7 a and 7 b are connected to the connection terminal array portion of the flexible wiring board 4. The back surface of the substrate is pressed with a predetermined pressure for a predetermined time. At this time, as shown in FIG. 3B, the pressing sheet plates 721 constituting the pressing surfaces 7a and 7b inclined by the angles θ and −θ, respectively, with respect to the pressing direction P bend the tip. Since each tip surface is pressed against the flexible wiring board 4, the component forces p1a and p1b acting along the back surface of the flexible wiring board 4 increase and the component force p2a acting perpendicularly to the flexible wiring board 4 increases. , P2b decreases, and the component forces p2a and p2b are alleviated by the elastic force against the bending of each pressing sheet plate 721 itself.

  Thereby, the elongation in the surface direction due to the thermal expansion indicated by the arrow A of the heated flexible wiring board 4 is effectively suppressed by the increased component forces p1a and p1b. That is, as shown in FIG. 3 (c), since each pressing sheet plate 721 is only closely overlapped and not bonded, a slight gap is generated between the respective bent tip portions, A connection terminal row that is heated and pressed by the pressing head 7 as a result of the heat expansion of the flexible wiring board 4 entering these gaps as fine wrinkles because the expansion is suppressed by the component forces p1a and p1b. The elongation as a whole is suppressed.

  In addition, the component forces p2a and p2b acting perpendicularly to the flexible wiring board 4 are not only reduced by the bending of the tip portion of each pressing sheet plate 721, but are also relaxed by the elastic force against the bending. The problem of damaging the flexible wiring board 4 softened by the pressure contact of the front end surface of each pressing sheet plate 721 is effectively prevented.

  As described above, according to the thermocompression bonding apparatus of this embodiment, the pressing sheet plate 721 made of a plurality of high thermal conductive elastic materials is pressed to the opposite sides with respect to the pressing direction P by the same angle θ. The pair of pressing surfaces 7a and 7b, which are the tip surfaces of the respective pressing sheet plates 721 that are bundled, are superposed by tilting the side toward the head center side, and heated to a predetermined temperature and at the connection terminal row portion of the flexible wiring board 4 Since the back surface is brought into direct contact with a predetermined pressure at a predetermined pressure, the component forces p1a and p1b parallel to the contact surface of the pressing force P are increased by the bending of the front end portion of each pressing sheet plate 721 and are applied to the flexible wiring board 4. In contact with each other, by suppressing the expansion of the flexible wiring board 4 due to thermal expansion, the extended portion of the flexible wiring board 4 enters the fine gap formed between the tip portions of the bent pressing sheet plates 721 as wrinkles. . As a result, the extension in the length direction (terminal array direction) of the entire connection terminal row portion of the flexible wiring board 4 to which the pressing surfaces 7a and 7b are in pressure contact is effectively absorbed, and the displacement of the connection terminals is eliminated. Even when the connection terminals on the first side are arranged in parallel with each other with a fine pitch, the corresponding connection terminals can always be reliably connected to each other.

  Next, another embodiment of the present invention will be described with reference to FIG. In addition, the same code | symbol is attached | subjected about the component same as the said embodiment, and the description is abbreviate | omitted.

  In the above-described embodiment, the tip portions of the press sheet plates 721 of the pair of press sheet bundles 72a and 72b of the press head 7 are inclined inward toward the pressing tip side. On the contrary, the pressing sheet plate 721 is inclined to the outside (opposite to the head center side) by the same angle θ, and the other configurations are substantially the same.

  That is, a center convex portion 812 is provided at the center of the length direction Xh on the surface 8111 of the base block 81 of the pressing head 8 facing the pressing direction P of the base portion 811. A pair of inclined side surfaces 8121 are inclined outward toward the pressing tip side. Accordingly, the inner side surfaces 841 of the pair of holding blocks 84 that sandwich the plurality of pressing sheet plates 821 with the center convex portion 812 are also inclined outward toward the distal end side in parallel with the opposing inclined side surfaces 8121.

  According to the pressing head 8 configured as described above, the directions of the respective component forces along the pressing surfaces 8a and 8b of the pressing force generated by pressing the pressing surfaces 8a and 8b against the flexible wiring board are heated. In this direction, the expansion of the flexible wiring board that expands due to the expansion is promoted. Therefore, the thermocompression bonding apparatus according to the present embodiment is used for thermocompression bonding of a flexible wiring board in which the connection terminal pitch is reduced by, for example, about 0.1% in anticipation of expansion due to thermal expansion. It is effectively used when the amount of elongation due to thermal expansion becomes less than expected due to a change in pressure-bonding conditions or a change in environmental conditions accompanying the change, and it becomes necessary to promote the elongation due to thermal expansion.

In addition, this invention is not limited to said embodiment.
For example, the pressing surface of the pressing head in the above embodiment is merely polishing and flattening the respective front end surfaces of the pressing sheet plate, but the release surface of the anisotropic conductive adhesive to the binder resin is flat on the flat pressing surface. An overcoat layer made of, for example, a fluorine-based coating material having excellent properties may be applied. As a result, the anisotropic conductive adhesive that is heated and pressed and protrudes from the side of the flexible wiring board is reliably prevented from sticking to the pressing surface, and the workability of the thermocompression bonding process is improved.

  Further, in the above embodiment, a plurality of pressing sheet plates are arranged to be inclined at the same angle by the same number on both sides of the center convex portion of the base block, but not limited to this, flexible wiring of the workpiece When the parallel pitch of the connection terminals on the board changes, the thickness, number of sheets and inclination angle of the pressure sheet plate are set on both sides of the boundary where the pitch changes depending on the size of the pitch and the length of the connection terminal row. What is necessary is just to set optimally.

  In addition, the thermocompression bonding apparatus for a flexible wiring board according to the present invention is not limited to the thermocompression bonding of the flexible wiring board in the liquid crystal display module, and the thermocompression bonding of the flexible wiring board in other various image display modules such as an organic EL display module. Of course, the present invention can be effectively applied to bonding.

It is a perspective view which shows the liquid crystal display module manufactured with the thermocompression bonding apparatus as one Embodiment of this invention. (A) is a side view which shows the thermocompression bonding process of the flexible wiring board by the said thermocompression bonding apparatus, (b) is a top view which expands and shows the thermocompression bonding part. (A) is a top view which shows the press head front end surface in the said thermocompression bonding apparatus, (b) is typical sectional drawing which expanded and showed the thermocompression bonding state by the press head. (A)-(d) is explanatory drawing for every step which shows the assembly procedure of the press head in the said thermocompression bonding apparatus, respectively. It is a partially exploded front view which shows the press head as other embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Liquid crystal display panel 11, 12 Glass substrate 14a, 14b Lead wiring 15 Input wiring 151 Connection terminal (liquid crystal display panel side)
2 Driver chip 3, 5 Anisotropic conductive adhesive 4 Flexible wiring board 41 Wiring 411 Connection terminal (flexible wiring board side)
6 Work table 7, 8 Press head 7a, 7b, 8a, 8b Press surface 71, 81 Base block 721, 821 Press sheet plate 73, 83 Holding plate 74, 84 Holding block

Claims (7)

A plurality of wirings are formed on the circuit board on which a plurality of wirings are formed and the first connection terminals of the respective wirings are arranged in parallel at a first pitch to form the first connection terminal row. Conductive particles are dispersed and mixed in a thermosetting binder resin in a flexible wiring board in which second connection terminals are arranged in parallel at a second pitch corresponding to the first pitch to form a second connection terminal array. Flexible that heats and pressurizes through the anisotropic conductive adhesive formed and sandwiches the conductive particles between the first connection terminal and the second connection terminal corresponding to each other, thereby electrically connecting the connection terminals. A thermocompression bonding apparatus for a wiring board,
A pressure head that heats and pressurizes the back surface opposite to the surface on which the second connection terminal row of the connection terminal row portion of the flexible wiring board on which the second connection terminal row is formed;
In the pressing head, a plurality of thin plate materials made of a high thermal conductive elastic material are stacked to be inclined with respect to the pressing direction, and a tip surface of a bundle of thin plate materials stacked at the same inclination angle forms a pressing surface. And
The pressing surface is brought into direct contact with the back surface of the connection terminal row portion of the flexible wiring board so that the overlapping direction of the thin plate members is parallel to the parallel arrangement direction of the second connection terminals. A thermocompression bonding apparatus for flexible wiring boards.   The second pitch is constant over the entire second connection terminal row, and the thin plate members are overlapped at an angle of the same size to the opposite sides with respect to the pressing direction, and the stacked thin plate members are stacked. The thermocompression bonding apparatus for a flexible wiring board according to claim 1, wherein the tip surfaces of the pair of bundles form a pair of pressing surfaces.   The second pitch is the same as the first pitch of the first connection terminal row, and the pair of bundles of thin plate members are inclined with their respective tip portions approaching each other toward the pressure tip side. The thermocompression bonding apparatus for a flexible wiring board according to claim 2.   The second pitch is reduced at a predetermined rate with respect to the first pitch of the first connection terminal row, and the pair of thin plate members has their tip portions facing each other toward the pressing tip side. The thermocompression bonding apparatus for a flexible wiring board according to claim 2, wherein the apparatus is inclined at a distance. The thin plate material has a thickness t,
5μm ≦ t ≦ 500μm
The thermocompression bonding apparatus for a flexible wiring board according to any one of claims 1 to 4, wherein the metal sheet is a metal plate. The inclination angle θ of the thin plate material is
1 ° ≦ θ ≦ 30 °
The thermocompression bonding apparatus for a flexible wiring board according to any one of claims 1 to 5, wherein the thermocompression bonding apparatus is characterized in that:   The circuit board on which the first connection terminal is disposed is one substrate of a liquid crystal display panel in which liquid crystal is sandwiched between a pair of substrates. A thermocompression bonding apparatus for a flexible wiring board according to any one of the claims.

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