JP2006140266A - Manufacturing method of flexible circuit board mounter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a flexible circuit board mounter of high electrical reliability by preventing the peeling of a flexible circuit board from a pressure-bonding board. <P>SOLUTION: In a board moving process, one or both of a pressure-bonding board and a flexible circuit board are moved, and the flexible circuit board and the pressure-bonding board are inserted between upper and lower pressure-bonding tools which are arranged to face the pressure-bonding board across the flexible circuit board arranged vertical to the pressure-bonding board and formed with an interval narrower than the width of the flexible circuit board, so that the flexible circuit board is so bent as to pinch the pressure-bonding board with the flexible circuit board. In a pressure-bonding process, the upper and lower pressure-bonding tools are used to pressure-bond both surfaces of the flexible circuit board and the pressure-bonding board at the same time, and to form a mounter connecting first and second wiring patterns to a connection terminal. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for manufacturing a flexible circuit board mounting body, and more particularly to a method for manufacturing a flexible circuit board mounting body in which flexible circuit boards are mounted on both surfaces of a pressure-bonding substrate.

  So far, liquid crystal optical elements have been developed for the purpose of correcting aberrations of DVD optical pickups. This liquid crystal optical element only modulates the forward laser beam, but in order to increase the recording density of the DVD, it is necessary to separately modulate the respective forward and backward laser beams. Thus, a liquid crystal optical element having two liquid crystal layers was developed. This liquid crystal optical element has a mounting area having a wiring pattern for connection with an external circuit on both the front and back surfaces of a middle glass substrate, and a single flexible circuit board is bent in this mounting area to perform double-sided mounting. Thus, the two stacked liquid crystal layers can be driven simultaneously.

A conventional method for mounting a flexible circuit board on a liquid crystal optical element will be described.
Up to now, the method of manufacturing a flexible circuit board mounting body in which a flexible circuit board is mounted on both sides of a glass substrate is mounted on the surface of the glass substrate by thermocompression bonding, and then the glass substrate is reversed and the flexible circuit board is mounted on the back surface. This is done by further mounting the substrate by thermocompression bonding. Therefore, in the case of a glass substrate in a large liquid crystal panel for display or the like, it is difficult to invert the glass substrate, so a flexible circuit that mounts a flexible circuit substrate on both sides of the glass substrate without inverting the glass substrate. A method of manufacturing a substrate mounting body has already been proposed (see, for example, Patent Document 1).

[Description of Manufacturing Method of Conventional Flexible Circuit Board Mounted Body: FIG. 4]
The conventional manufacturing method will be described with reference to FIG. FIG. 4 is a process sectional view showing a conventional method for manufacturing a flexible circuit board mounting body.

  First, as shown in FIG. 4A, one surface of the glass substrate 1b is fixed on the lower crimping tool 19 by vacuum suction or the like. Then, the anisotropic conductive film 7 is temporarily pressure-bonded on the first wiring pattern 3 formed on the other surface of the glass substrate 1b, and the first connection terminals of the first wiring pattern 3 and the flexible circuit board 11 are connected. The first wiring pattern 3 and the first connection terminal 13 are electrically connected to each other by thermocompression bonding using the upper crimping tool 17.

  Next, as shown in FIG. 4B, the other surface of the glass substrate 1b, that is, the surface to which the flexible circuit substrate 11 is bonded is fixed to the upper crimping tool 17 by vacuum suction or the like. Is released from the lower crimping tool 19. Thereafter, the anisotropic conductive film 7 is temporarily pressure-bonded onto the second wiring pattern 5 formed on one surface of the glass substrate 1b. Next, the flexible circuit board 11 is bent, and alignment is performed so that the second wiring pattern 5 and the second connection terminal 15 of the flexible circuit board 11 are matched.

  Finally, as shown in FIG. 4C, thermocompression bonding is performed with the lower crimping tool 19 to electrically connect the second wiring pattern 5 and the second connection terminal 15. Thereafter, the glass substrate 1 b is released from the upper crimping tool 17. Thus, the liquid crystal optical element 21 which is a flexible circuit board mounting body in which the first wiring pattern 3 and the first connection terminal 13 and the second wiring pattern 5 and the second connection terminal 15 are electrically connected is obtained. be able to.

Japanese Patent Publication No. 2000-102882 (page 5, FIGS. 1 to 3).

  However, the method for manufacturing a flexible circuit board mounting body in the prior art can mount the flexible circuit board on both surfaces of the glass substrate by the above-mentioned means, but has the following problems.

  In the conventional manufacturing method, when a flexible circuit board is mounted on both surfaces of a glass substrate, the flexible circuit board is mounted on the surface of the glass substrate by thermocompression bonding via an anisotropic conductive film, and then the back surface is anisotropic. A flexible circuit board is mounted by thermocompression bonding through a conductive film. For this reason, when mounting one flexible circuit board on both surfaces of a glass substrate, it is necessary to first bend the flexible circuit board after mounting the flexible circuit board on the surface of the glass substrate by thermocompression bonding. When this bending is performed, stress is applied to the flexible circuit board, and the flexible circuit board mounted first may be peeled off from the mounting area of the glass substrate. Even when there is no peeling at the time of bending, there is a case where the flexible circuit board mounted on the front surface is displaced or peeled off from the mounting region due to heating when the back surface is mounted. This is because the resin serving as the binder in the anisotropic conductive film on the first mounted surface is melted by heating during mounting on the back surface. As a result, there is a problem in that the electrical connection between the glass substrate and the flexible circuit board becomes insufficient, and the electrical reliability is impaired.

(Object of invention)
Accordingly, an object of the present invention is to solve the above-mentioned problems, and in a manufacturing process of mounting a flexible circuit board on both surfaces of a glass substrate, the flexible circuit board is peeled off by bending of the flexible circuit board, or the flexible circuit is heated by pressure bonding. It is an object of the present invention to provide a manufacturing method of a flexible circuit board mounting body that can be mounted without causing displacement or peeling of the board and that can obtain an electrically reliable flexible circuit board mounting body.

  In order to achieve the above object, the production method of the present invention employs the following means.

  The manufacturing method of the flexible circuit board mounting body of the present invention includes a crimping board on which both the first wiring pattern and the second wiring pattern are formed on both sides, and a flexible circuit board provided with connection terminals at side portions of the crimping board. In the method of manufacturing a flexible circuit board mounting body in which the connection terminals are connected to the first wiring pattern and the second wiring pattern, respectively, the flexible circuit board is flexible in a direction perpendicular to the crimping board. The substrate placement process of placing the flexible circuit board on the fixed tool and either the crimp board or the flexible circuit board, or both, so that the connection terminal forming surface of the circuit board faces one side of the crimp board It is moved and placed opposite to the crimping board across the vertically arranged flexible circuit board, and more than the width of the flexible circuit board. Inserting the flexible circuit board and the crimping board between the upper and lower crimping tools arranged at a large interval, bending the flexible circuit board so that the flexible circuit board sandwiches the crimping board, and the upper and lower crimping tools. And a crimping step of simultaneously crimping the flexible circuit board on both sides of the crimping substrate to form a mounting body in which the first and second wiring patterns and the connection terminals are connected.

Further, the substrate moving step moves either one or both of the crimping substrate and the flexible circuit board, abuts the one surface on which the connection terminal of the flexible circuit board is formed, and the side surface of the crimping substrate, After the other surface of the flexible circuit board is brought into contact with the end surfaces of the upper and lower crimping tools, the flexible circuit board is released from the fixed tool, and the flexible circuit board is opened between the upper and lower crimping tools. A crimping substrate is inserted.

  In the substrate mounting process, after positioning the flexible circuit board and the crimping board, both the boards are fixed at predetermined positions so that the flexible circuit board is in a direction perpendicular to the crimping board. Features.

  Further, the pressure-bonding substrate is a glass substrate constituting a liquid crystal panel.

  According to the method for manufacturing a flexible circuit board mounting body of the present invention, the flexible circuit board is bent before being mounted by thermocompression bonding between the glass board and the flexible circuit board by inserting the flexible circuit board between the upper and lower crimping tools together with the glass board. The circuit board can be bent, and then the flexible circuit board can be simultaneously crimped and mounted on both surfaces of the glass substrate using upper and lower crimping tools. For this reason, the shift | offset | difference and peeling of the flexible circuit board mounted on both surfaces of the glass substrate can be prevented. As described above, according to the present invention, it is possible to provide a method for manufacturing a flexible circuit board mounting body that can realize an electrically reliable flexible circuit board mounting body.

  Hereinafter, the manufacturing method of the flexible circuit board mounting body of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing the structure of a flexible circuit board mounting body according to the present invention. 2 and 3 are process cross-sectional views showing the manufacturing method of the present invention. In the figure, members having the same shape as in the prior art are denoted by the same reference numerals.

[Description of Manufacturing Method of Flexible Circuit Board Mounted Body in the Present Invention: FIG. 1]
FIG. 1A is an exploded perspective view of a flexible circuit board mounting body of the present invention, showing a flexible circuit board and a liquid crystal cell, and FIG. 1B is a flexible circuit board mounting body in which the flexible circuit board is mounted on the liquid crystal cell. It is a perspective view which shows a certain liquid crystal optical element.
In the method for manufacturing a flexible circuit board mounting body according to the present invention, as shown in FIG. 1A, a first wiring pattern (not shown) and a second wiring pattern (not shown) are formed on both surfaces. A surface 11a on which a connection terminal (not shown) of the flexible circuit board 11 is formed is brought into contact with the side surface 2 of the glass substrate 1b in the liquid crystal cell 10 as a pressure-bonding substrate, and the flexible circuit board is shown in FIG. 11 is bent so as to sandwich the glass substrate 1b, and then the flexible circuit board 11 is simultaneously pressure-bonded to both surfaces of the glass substrate 1b, so that a first wiring pattern (not shown) and a second wiring pattern (not shown) are attached. ) Are connected to connection terminals (not shown), respectively, so that an electrically reliable flexible circuit board mounting body, that is, a liquid crystal cell 10 is connected to the liquid crystal cell 10. It is possible to obtain a liquid crystal optical element 21 mounted with Kishiburu circuit board 11. Hereinafter, specific examples of the manufacturing process of the flexible circuit board mounting body will be described.

[Description of Manufacturing Method of Flexible Circuit Board Mounted Body in the Present Invention: FIGS. 2 to 3]
Fig.2 (a) is a figure for demonstrating the schematic cross section which shows the AA cross section in Fig.1 (a), and explaining the manufacturing process of a flexible circuit board mounting body. First, as shown in FIG. 2A, the liquid crystal cell 10 including the glass substrate 1 b is placed on the pressure-bonding substrate stage 31. At this time, the liquid crystal cell 10 is fixed on the pressure-bonded substrate stage 31 by vacuum suction. The flexible circuit board 11 is in a direction perpendicular to the liquid crystal cell 10, and one surface of the flexible circuit board 11, that is, the formation surface 11a of the connection terminals 13 and 15 and one side surface 2 of the glass substrate 1b are opposed to each other. And is placed on the flexible circuit board stage 33. At this time, the flexible circuit board 11 is fixed on the flexible circuit board stage 33 by vacuum suction. Here, the position of the first wiring pattern 3 on the glass substrate 1b and the first connection terminal 13 on the flexible circuit board 11, and the second wiring pattern 5 on the glass substrate 1b and the flexible circuit board 11 The positions of the pressure-bonded substrate stage 31 and the flexible circuit board stage 33 are adjusted in advance so that the positions of the second connection terminals 15 are matched with each other.

  Here, the liquid crystal cell 10 injects liquid crystal (not shown) into the gap between the glass substrate 1a and the glass substrate 1b and the gap between the glass substrate 1b and the glass substrate 1c, respectively, and the glass substrate 1a, the glass substrate 1b, and the glass substrate 1b. And a glass substrate 1c are bonded to each other by an outer peripheral seal member (not shown).

  The glass substrate 1b has a first wiring pattern 3 made of a transparent electrode film on the front surface and a second wiring pattern 5 made of a transparent electrode film on the back surface. The flexible circuit board 11 is provided with a first connection terminal 13 and a second connection terminal 15 for connecting the first wiring pattern 3 and the second wiring pattern 5 of the glass substrate 1b. Nickel-gold plating may be applied to the surfaces of the first connection terminal 13 and the second connection terminal 15 in order to improve the adhesion between the first wiring pattern 3 and the second wiring pattern 5. preferable.

Further, an anisotropic conductive film 7 is temporarily bonded to the first wiring pattern 3 and the second wiring pattern 5 in advance. As the anisotropic conductive film 7, Anisolm AC-7104 (trade name), an anisotropic conductive film manufactured by Hitachi Chemical Co., Ltd., was used. The anisotropic conductive film 7 is temporarily pressure-bonded using a pressure bonding tool under the conditions of a heating temperature of 80 ° C., a pressure of 10 kg / cm ² , and a pressure bonding time of 5 sec.

  Next, as shown in FIG. 2B, the crimping substrate stage 31 is moved in the direction of the flexible circuit board 11, and the side surface 2 of the glass substrate 1 b and one surface of the flexible circuit board 11, that is, the connection terminals 13 and 15. The forming surface 11a is brought into contact. At this time, the upper crimping tool 17 and the lower crimping tool 19 are arranged at positions facing the glass substrate 1b with the flexible circuit board 11 arranged perpendicular to the glass substrate 1b interposed therebetween. The distance a between the upper and lower crimping tools 17 and 19 is set to a value smaller than the width b of the flexible circuit board 11.

  Next, as shown in FIG. 3A, the crimping substrate stage 31 and the flexible circuit board stage 33 are moved in the direction of the upper and lower crimping tools 17 and 19 to form the connection terminals 13 and 15 of the flexible circuit board 11. The other surface 11b on the opposite side of the surface is brought into contact with the upper and lower crimping tools 17 and 19. Here, the flexible circuit board 11 is released from the flexible circuit board stage 33 after contacting the upper and lower crimping tools 17 and 19.

  Further, as shown in FIG. 3 (b), the crimping substrate stage 31 is moved in the direction of the upper and lower crimping tools 17 and 19 so that it is flexible with the glass substrate 1b between the upper crimping tool 17 and the lower crimping tool 19. The circuit board 11 is inserted while being bent. Here, as shown in FIG. 2B, the gap b between the upper crimping tool 17 and the lower crimping tool 19 is set to be smaller than the width a when the flexible circuit board 11 is arranged vertically. Therefore, the flexible circuit board 11 bends to both sides of the glass substrate 1b as it is inserted between the upper and lower crimping tools 17 and 19.

Next, as shown in FIG. 3 (c), the flexible circuit board 11 is finally pressure-bonded to the glass substrate 1b at the same time with the upper pressure-bonding tool 17 and the lower pressure-bonding tool 19. Here, the main pressure bonding was performed under the conditions of a heating temperature of 170 ° C., a pressure of 20 kg / cm ² , and a pressure bonding time of 20 sec. Thereby, the first wiring pattern 3 on the glass substrate 1b and the first connection terminal 13 on the flexible circuit board 11, the second wiring pattern 5 on the glass substrate 1b and the second connection terminal on the flexible circuit board 11 are obtained. 15 are electrically connected to each other. Thereafter, the liquid crystal optical element 21 having the flexible circuit board 11 mounted on the liquid crystal cell 10 is released from the upper and lower crimping tools 17 and 19 and the crimping substrate stage 31. Through the above steps, an electrically reliable flexible circuit board mounting body as shown in FIG. 1B, that is, a liquid crystal optical element 21 in which the flexible circuit board 11 is mounted on the liquid crystal cell 10 is completed.

  As is clear from the above description, in the present invention, the flexible circuit board 11 and the glass substrate 1b are moved and inserted between the upper and lower crimping tools 17 and 19, thereby allowing the glass substrate 1b and the flexible circuit board 11 to be inserted. And can be bent before mounting by thermocompression bonding. For this reason, stress is applied to the flexible circuit board when it is bent as in the conventional example, and the flexible circuit board on the surface of the first mounted glass substrate is not peeled off from the glass substrate.

  In the present invention, the glass substrate 1b and the flexible circuit board 11 can be thermocompressed simultaneously with the upper and lower crimping tools 17 and 19 simultaneously. For this reason, the flexible circuit board 11 previously mounted on the surface of the glass substrate 1b is not displaced or peeled off due to heating by thermocompression of the back surface of the glass substrate 1b and the flexible circuit board 11 as in the conventional example.

  Therefore, according to the present invention, in the mounting process of mounting the flexible circuit board 11 on both surfaces of the glass substrate 1b, the flexible circuit board 11 and the glass substrate 1b can be reliably mounted without causing displacement or peeling. It is possible to provide a method for manufacturing a flexible circuit board mounting body in which a flexible circuit board mounting body with reliable electrical connection and high reliability can be obtained.

  In addition, although the example which used the glass substrate as a crimping substrate was demonstrated in the present Example, the same effect can be acquired also in the case of substrates, such as a glass epoxy circuit board and a ceramic circuit board, instead of a glass substrate as a crimping substrate. it can.

  In the embodiment, the glass substrate is moved in the direction of the flexible circuit board, and then the glass substrate and the flexible circuit board are moved in the direction of the upper and lower crimping tools. However, the embodiment is limited to this. The same effect can be obtained even if the glass substrate, the flexible circuit board, and the upper and lower crimping tools are moved simultaneously with each other.

It is a perspective view which shows the structure of the flexible circuit board mounting body in embodiment of this invention. It is process sectional drawing which shows the manufacturing method of the flexible circuit board mounting body in embodiment of this invention. It is process sectional drawing which shows the manufacturing method of the flexible circuit board mounting body in embodiment of this invention. It is process sectional drawing which shows the manufacturing method of the conventional flexible circuit board mounting body.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1b Glass substrate 2 Side surface of glass substrate 3 1st wiring pattern 5 2nd wiring pattern 7 Anisotropic conductive film 10 Liquid crystal cell 11 Flexible circuit board 11a One side of a flexible circuit board 13 1st connection terminal 15 2nd Connection terminal 17 Upper crimping tool 19 Lower crimping tool 21 Liquid crystal optical element

Claims (4)

A crimping substrate on which both the first wiring pattern and the second wiring pattern are formed, and a flexible circuit board provided with connection terminals are bent at side portions of the crimping substrate, and the first wiring pattern In the method for manufacturing a flexible circuit board mounting body in which the connection terminals are connected to the second wiring patterns, respectively.
The flexible circuit board is placed on a fixing tool so that the connection terminal forming surface of the flexible circuit board and one side surface of the crimp board face each other in a direction perpendicular to the crimp board. A substrate placing step to perform,
Either one or both of the pressure-bonding substrate and the flexible circuit board are moved so as to face the pressure-bonding board across the vertically arranged flexible circuit board and are narrower than the width of the flexible circuit board. A board moving step of inserting the flexible circuit board and the crimp board between upper and lower crimping tools arranged at intervals, and bending the flexible circuit board so that the flexible circuit board sandwiches the crimp board;
Using the upper and lower crimping tools, a crimping step of simultaneously crimping the flexible circuit board on both sides of the crimping board to form a mounting body connecting the first and second wiring patterns and the connection terminals; ,
The manufacturing method of the flexible circuit board mounting body characterized by the above-mentioned.   In the substrate moving step, either one or both of the crimp substrate and the flexible circuit substrate are moved, and the one surface on which the connection terminal of the flexible circuit substrate is formed and the side surface of the crimp substrate are brought into contact with each other. Then, after the other surface of the flexible circuit board is brought into contact with the end surfaces of the upper and lower crimping tools, the flexible circuit board is released from the fixed tool, and the flexible circuit board is opened in the state where the flexible circuit board is opened. The method for manufacturing a flexible circuit board mounting body according to claim 1, wherein the flexible circuit board and the crimping board are inserted between the crimping tools.   In the substrate mounting step, after positioning the flexible circuit board and the pressure-bonded substrate, both the substrates are fixed at a predetermined position so that the flexible circuit board is in a direction perpendicular to the pressure-bonded substrate. The manufacturing method of the flexible circuit board mounting body of Claim 1 or 2 characterized by the above-mentioned. The method for manufacturing a flexible circuit board mounting body according to any one of claims 1 to 3, wherein the pressure-bonding substrate is a glass substrate constituting a liquid crystal panel.

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