JP2008077574A - Touch panel and flexible connector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a touch panel capable of improving reliability of connection of a pair of sheets with a flexible connector of the touch panel. <P>SOLUTION: The touch panel 1 includes the pair of sheets 3 and 5 and the flexible connector 7 pressure-bonded thereto. The flexible connector 7 includes a first terminal part 29 electrically connected with a terminal pattern 13 (13a, 13b) of the sheet 3 and a second terminal part 31 electrically connected with a terminal pattern 13 (13c, 13d) of the sheet 5. The flexible connector 7 includes a metallic pattern 33 formed on one surface 41 of an insulating film 21 in opposition to the second terminal part 31 and having the same thickness as that of a first metallic wiring pattern 23. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a touch panel, and more particularly, to a flexible connector provided in a touch panel.

  The touch panel is an input device mounted on a PDA (personal digital assistant), a POS (point of sale) terminal, or the like in combination with a display such as an LCD (liquid crystal display). When the touch panel is touched with a finger or a pen, input to the computer is executed based on the touched position.

  The touch panel includes a sheet (for example, a film, a glass plate) and a flexible connector having one end connected to the sheet. The other end of the flexible connector is connected to the controller. The controller is a device that detects a position touched with a finger or a pen on the touch panel.

  The connection between the sheet and the flexible connector is a mechanical and electrical connection. When the sheet and the flexible connector are pressure-bonded using an anisotropic conductive adhesive, they can be mechanically and electrically connected. The sheet and the flexible connector are mechanically connected by the adhesive of the anisotropic conductive adhesive, and the terminals of the sheet and the flexible connector are electrically connected by the conductive particles of the anisotropic conductive adhesive.

If the reliability of the connection between the sheet and the flexible connector is poor, it immediately leads to a decrease in the reliability of the touch panel. Therefore, a technique for improving the reliability of the connection has been proposed (see, for example, Patent Document 1).
JP 2005-141463 A

  The objective of this invention is providing the touch panel which can improve the reliability of a connection of a pair of sheet | seat of a touch panel, and a flexible connector, and the flexible connector with which it is equipped.

  In the touch panel according to the present invention, an electrode pattern and a terminal pattern electrically connected thereto are formed, a pair of sheets arranged opposite to each other, and a pressure bonding between the pair of sheets and crimped to these A flexible connector electrically connected to the terminal pattern of the pair of sheets in the crimping region, the flexible connector comprising: an insulating film; and the insulating film First and second metal wiring patterns formed on one surface; a first terminal portion formed on and electrically connected to the first metal wiring pattern in the crimp region; and It is formed on the other surface of the insulating film and electrically connected to the second metal wiring pattern at a contact portion provided on the insulating film. A wiring pattern having a second terminal portion having the same thickness as the first terminal portion in the pressure-bonding region, and formed on one surface of the insulating film so as to face the second terminal portion, The metal pattern having the same thickness as the first metal wiring pattern, the pair of sheets in the crimping region, and the flexible connector are used for crimping, and one of the first terminal portion and the pair of sheets is used. An anisotropic conductive adhesive member that electrically connects the terminal pattern and electrically connects the second terminal portion and the other terminal pattern of the pair of sheets.

  In the touch panel according to the present invention, the flexible connector is further formed on the metal pattern, a first plating layer formed between the first metal wiring pattern and the first terminal portion, And a second plating layer having the same thickness as the first plating layer.

  The touch panel which concerns on this invention WHEREIN: The said metal pattern can be comprised with the same material as the said 1st and 2nd metal wiring pattern.

  The flexible connector which concerns on this invention is a flexible connector which has a crimping | compression-bonding area | region where an anisotropically conductive adhesive member is arrange | positioned, Comprising: The 1st and 2nd formed in one surface of an insulating film and the said insulating film Formed on the first metal wiring pattern of the crimping region, the first terminal portion electrically connected to the metal wiring pattern, and the other surface of the insulating film, A wiring pattern electrically connected to the second metal wiring pattern at a contact portion provided on the insulating film, and having a second terminal portion having the same thickness as the first terminal portion in the crimping region; And a metal pattern formed on one surface of the insulating film so as to face the second terminal portion and having the same thickness as the first metal wiring pattern.

  According to the touch panel of the present invention, the flexible connector provided in the touch panel is formed on one surface of the insulating film so as to face the second terminal portion, and has the same metal pattern as the first metal wiring pattern. including. Thereby, in the crimping region of the flexible connector, a hard portion (specifically, the first metal wiring pattern, the metal pattern, the first terminal portion, the first terminal portion, the second terminal portion side, and the second terminal portion side) 2 terminal portions) have the same thickness. Therefore, since the pressure at the time of crimping is uniformly applied to the first terminal portion side and the second terminal portion side, sufficient adhesive strength can be obtained on either side, and the pair of sheets of the touch panel and the flexible connector The reliability of the mechanical connection can be improved.

  In addition, both the electric resistance value between the first terminal portion and one terminal pattern of the pair of sheets and the electric resistance value between the second terminal portion and the other terminal pattern of the pair of sheets can be stabilized. I understood. Therefore, the reliability of electrical connection between the pair of sheets of the touch panel and the flexible connector can be improved.

  As described above, according to the touch panel of the present invention, the reliability of connection between the pair of sheets of the touch panel and the flexible connector can be improved.

  The flexible connector according to the present invention has the same configuration as the flexible connector provided in the touch panel according to the present invention. Therefore, according to the flexible connector which concerns on this invention, the reliability of a connection of a pair of sheet | seat of a touch panel and a flexible connector can be improved.

  Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is an exploded perspective view of a touch panel 1 according to the present embodiment. The touch panel 1 is a resistive film type, and includes a pair of sheets 3 and 5 and a flexible connector 7 disposed to face each other.

  The sheets 3 and 5 are a film or a thin glass plate. The configuration of the sheet 3 will be described. A transparent resistive film 9 made of ITO (Indium Tin Oxide) is formed on substantially the entire surface of the sheet 3 facing the sheet 5 side. On the transparent resistance film 9, two electrode patterns 11 are formed which are electrically connected to the transparent resistance film 9 and extend in the x direction.

  One of the electrode patterns 11 is located on one side of the two sides in the x direction of the sheet 3 and is electrically connected to the terminal pattern 13 (13a). Another one of the electrode patterns 11 is located on the other side of the two sides in the x direction of the sheet 3, and the terminal pattern 13 (13 b) located near the terminal pattern 13 (13 a) by the conductive pattern 15. Electrically connected. The electrode pattern 11, the terminal pattern 13, and the conductive pattern 15 are formed, for example, by screen printing using a silver paste as a material.

  The sheet 5 has the same configuration as the sheet 3, and the difference from the sheet 3 is that the electrode pattern 11 extends in the y direction. A double-sided tape for bonding the sheet 3 and the sheet 5 and a spacer disposed between the sheet 3 and the sheet 5 are not shown.

  The flexible connector 7 (hereinafter sometimes referred to as “connector 7”) is, for example, an FPC (Flexible Printed Circuit). The connector 7 is formed on the insulating film 21, the first metal wiring pattern 23 and the second metal wiring pattern 25 formed on one surface of the insulating film 21, and the second surface of the insulating film 21. A wiring pattern 27 electrically connected to the metal wiring pattern 25; a first terminal portion 29 formed on one surface of the insulating film 21 and electrically connected to the first metal wiring pattern 23; 2nd terminal part 31 which is the termination | terminus of the wiring pattern 27, and the metal pattern 33 formed in the one surface of the insulating film 21 are included.

  Among these components, those formed on one surface side of the insulating film 21 are indicated by solid lines, and those formed on the other surface side are indicated by dotted lines. The metal pattern 33 is one of the features of the touch panel 1 according to the present embodiment, and will be described in detail later.

  First and second terminal portions 29 and 31 are located at one end 35 of the connector 7. At one end 35, one of the first terminal portions 29 is electrically connected to the terminal pattern 13 (13a), and the other is electrically connected to the terminal pattern 13 (13b). Similarly, at one end 35, one of the second terminal portions 31 is electrically connected to the terminal pattern 13 (13c), and the other is electrically connected to the terminal pattern 13 (13d). The connector 7 is connected to a controller (not shown) at the other end 37.

  In this embodiment, the flexible connector 7 in which the 1st and 2nd metal wiring patterns 23 and 25 are formed only in one side (here one side) instead of both sides of the insulating film 21 is assumed. When using such a connector 7, in order to electrically connect the second metal wiring pattern 25 and the second terminal portion 31 formed on the other surface of the insulating film 21, A wiring pattern 27 is formed on the other surface.

  Next, details of the flexible connector 7 will be described mainly using FIG. 2 (using FIG. 1 and FIG. 3 as necessary). FIG. 2 is an enlarged plan view of the connector 7. 3 is a cross-sectional view of the connector 7 shown in FIG. 2 taken along the lines A1-A2, B1-B2, and C1-C2.

  As shown in FIG. 2, one end 35 side of the flexible connector 7 is made wider than the other end 37 side shown in FIG. One end 35 of the connector 7 is a crimping region R1. In the crimping region R1, the connector 7 is sandwiched and crimped between the pair of sheets 3 and 5 shown in FIG. 1 and is electrically connected to the terminal pattern 13 formed on the pair of sheets 3 and 5.

  For example, first and second metal wiring patterns 23 and 25 are formed on one surface 41 (FIGS. 3A and 3B) of the flexible insulating film 21 made of polyimide. There are two first and second metal wiring patterns 23 and 25, respectively, which are formed by patterning a metal thin film (for example, a copper thin film).

  On one surface 41 of the insulating film 21, a transparent protective film 43 (FIGS. 3A and 3B) that covers the first and second metal wiring patterns 23 and 25 is formed. One surface 41 of the insulating film 21 excluding the pressure-bonding region R1 serves as a formation region R2 of the transparent protective film 43. The reason why the transparent protective film 43 is not formed in the crimping region R1 is to electrically connect the first terminal portion 29 and the terminal pattern 13 (13a, 13b) of the sheet 3 in the crimping region R1.

  The first metal wiring pattern 23 extends on one surface 41 of the insulating film 21 and reaches the crimping region R1 (FIG. 3C). Since the first metal wiring pattern 23 is a copper thin film, the plating layer 45 shown in FIG. 3C is formed on the first metal wiring pattern 23 except for the formation region R2 of the transparent protective film 43 to prevent oxidation. (First plating layer) is formed.

  The first terminal portion 29 is electrically connected to the first metal wiring pattern 23, and on the first metal wiring pattern 23 in the crimping region R1 through the plating layer 45 (first plating layer). Is formed. The 1st terminal part 29 is a metal powder containing film | membrane (for example, silver paste), and the 2nd terminal part 31 and the wiring pattern 27 are the same. The first terminal portion 29, the second terminal portion 31, and the wiring pattern 27 are formed by screen printing, for example.

  The wiring pattern 27 is formed on the other surface 47 (FIG. 3B) of the insulating film 21. The wiring pattern 27 is electrically connected to the second metal wiring pattern 25 at a contact portion 49 provided on the insulating film 21. The contact portion 49 is formed in a through hole 51 provided in the insulating film 21 as shown in FIG. The contact portion 49 includes a plating layer 45 applied to the second metal wiring pattern 25 exposed in the through hole 51 and a material (silver paste) of the wiring pattern 27 embedded in the through hole 51 when the wiring pattern 27 is formed. ).

  When the through hole 51 is formed in the insulating film 21, the through hole 51 may be formed up to the second metal wiring pattern 25 and may penetrate therethrough. In such a state, the conduction between the second metal wiring pattern 25 and the wiring pattern 27 becomes poor. Therefore, after the through hole 51 is formed in the contact portion 49, a metal such as a silver paste is formed on the second metal wiring pattern 25. A powder-containing film 61 is formed. The metal powder-containing film 61 is formed by screen printing, for example.

  The wiring pattern 27 extends on the other surface 47 of the insulating film 21 and reaches the crimping region R1. The wiring pattern 27 on the crimping region R1 becomes the second terminal portion 31 (FIG. 3C). A transparent protective film 53 (FIG. 3B) that covers the wiring pattern 27 is formed on the other surface 47 of the insulating film 21. Since the second terminal portion 31 and the terminal pattern 13 (13c, 13d) of the sheet 5 are electrically connected in the crimping region R1, the transparent protective film 53 is not formed in the crimping region R1. “R3” indicates a region where the transparent protective film 53 is formed.

  A cut 55 is formed in the insulating film 21 on the one end 35 side of the flexible connector 7. Thereby, the insulating film 21 branches, the 1st terminal part 29 is arrange | positioned at one side, and the 2nd terminal part 31 is arrange | positioned at the other. The notch 55 is provided in order to eliminate the stress caused by the difference in thermal expansion coefficient between the sheet 3 and the sheet 5 when the materials of the sheet 3 and the sheet 5 are different.

  Anisotropic conductive adhesive members 57 and 59 are formed in the crimping region R1. The anisotropic conductive adhesive members 57 and 59 are obtained by dispersing conductive particles in an adhesive, and specifically, an anisotropic conductive adhesive or an anisotropic conductive film. The anisotropic conductive adhesive members 57 and 59 are used for thermocompression bonding of the pair of sheets 3 and 5 and the flexible connector 7 in the crimping region R1. By this thermocompression bonding, the flexible connector 7 and the pair of sheets 3 and 5 are mechanically and electrically connected. The adhesive of the anisotropic conductive adhesive members 57 and 59 contributes to mechanical connection, and the conductive particles contribute to electrical connection.

  As shown in FIG. 3C, the anisotropic conductive adhesive member 57 is one side of the insulating film 21 so as to cover the first terminal portion 29 on the first terminal portion 29 side from the notch 55. The surface 41 is formed. By the conductive particles of the anisotropic conductive adhesive member 57, the first terminal portion 29 and the terminal pattern 13 (13a, 13b) of the sheet 3 (one of the pair of sheets) are electrically connected.

  On the other hand, the anisotropic conductive adhesive member 59 is formed on the other surface 47 of the insulating film 21 so as to cover the second terminal portion 31 on the second terminal portion 31 side from the notch 55. Has been. By the conductive particles of the anisotropic conductive adhesive member 59, the second terminal portion 31 and the terminal pattern 13 (13c, 13d) of the sheet 5 (the other of the pair of sheets) are electrically connected.

  In the crimping region R <b> 1, a metal pattern 33 facing the second terminal portion 31 is formed on the second terminal portion 31 side from the notch 55. The metal pattern 33 is located on the one surface 41 side of the insulating film 21. The metal pattern 33 is a copper thin film, for example. Since the metal pattern 33 is formed in the pressure-bonding region R <b> 1, it is not covered with the transparent protective film 43. Therefore, it is covered with the plating layer 45 (second plating layer) to prevent oxidation. The metal pattern 33 is formed together when the first metal wiring pattern 23 and the second metal wiring pattern 25 are patterned.

  The main effects of this embodiment will be described. According to this embodiment, the metal pattern 33 is formed on the connector 7. Therefore, in the crimping | compression-bonding area | region R1 of the flexible connector 7, the thickness by the side of the 1st terminal part 29 and the thickness by the side of the 2nd terminal part 31 become the same. This will be specifically described with reference to FIG.

  FIG. 3C shows a cross section of the crimping region R <b> 1 of the flexible connector 7. The first metal wiring pattern 23 and the metal pattern 33 are formed by patterning a metal thin film (for example, a copper thin film), and both have a thickness of 10 μm. The first terminal portion 29 and the second terminal portion 31 are formed by screen printing and both have a thickness of 8 μm. The thickness of the plating layer 45 is 1 μm. The thickness of the second metal wiring pattern 25 shown in FIGS. 3A and 3B is 10 μm similarly to the first metal wiring pattern 23 and the metal pattern 33.

In the crimping region R1 of the flexible connector 7, the thickness of the metal layer on the first terminal portion 29 side and the thickness of the metal layer on the second terminal portion 31 side are as follows.
(1) First terminal portion 29 side The thickness of the first metal wiring pattern 23 is 10 μm + the thickness of the plating layer 45 (first plating layer) is 1 μm + the thickness of the first terminal portion 29 is 8 μm = 19 μm.
(2) Second terminal portion 31 side The thickness of the second terminal portion 31 is 8 μm + the thickness of the metal pattern 33 is 10 μm + the thickness of the plating layer 45 (second plating layer) is 1 μm = 19 μm.

  When the material of the first metal wiring pattern 23 or the metal pattern 33 is difficult to oxidize, the plating layer 45 (first plating layer) on the first metal wiring pattern 23 or the plating layer 45 (second second) on the metal pattern 33. Plating layer) becomes unnecessary. Also in this case, the thickness of the metal layer on the first terminal portion 29 side and the thickness of the metal layer on the second terminal portion 31 side are the same.

  FIG. 4 is an enlarged cross-sectional view of the crimping region R1 when the pair of sheets 3 and 5 and the flexible connector 7 are crimped. As described above, in the crimping region R1, since the thickness of the metal layer (in other words, a hard portion) is the same on the first terminal portion 29 side and the second terminal portion 31 side, the pressure P during the crimping is the first. Are uniformly applied to the terminal portion 29 side and the second terminal portion 31 side. Therefore, since sufficient adhesive strength can be obtained on either side, the reliability of the mechanical connection between the pair of sheets 3 and 5 of the touch panel 1 and the flexible connector 7 can be improved.

Furthermore, according to this embodiment, the reliability of the electrical connection between the pair of sheets 3 and 5 of the touch panel 1 and the flexible connector 7 can also be improved. This will be specifically described using data. As shown in Table 1, six samples were prepared by thermocompression bonding a pair of sheets 3 and 5 and a flexible connector 7. These samples were different in temperature, pressure, and time during thermocompression bonding. The values of Level 1, Level 2, and Level 3 are shown in Table 2.

The electric resistance value between the first terminal portion 29 and the terminal pattern 13 (13a, 13b) and the electric resistance value between the second terminal portion 31 and the terminal pattern 13 (13c, 13d) Each was measured. Thereafter, Samples 1 to 6 were put in a test tank having a temperature of 85 ° C. and a humidity of 90% and left for 960 hours. Again, their electrical resistance values were measured for each of Samples 1-6. The results are shown in Table 3.

  “First” in Table 3 is an electric resistance value column between the first terminal portion 29 and the terminal pattern 13 (13a, 13b), and “second” is the second terminal portion 31 and the terminal pattern 13 ( 13c, 13d) is an electric resistance value column. “Initial” is a column of the electric resistance value before being left in the test tank, and “960h” is a column of the electric resistance value after 960 hours have been left in the test tank. The unit of electrical resistance is ohms.

  The electric resistance value of “960h” changed most with respect to the “initial” electric resistance value from 1.7 to 1.9 of “second” of sample 4 and increased by about 1.12 times. . When the electrical resistance value of “960h” was less than 1.50 times the “initial” electrical resistance value, all of the samples 1 to 6 passed.

For comparison, Samples 1 to 3 for comparison were prepared, and the electrical resistance value was measured. The configuration of the comparative samples 1 to 3 is different from the configurations of the samples 1 to 6 in that the metal pattern 33 and the plating layer 45 thereon are not shown in FIG. The temperature, pressure, and time during thermocompression bonding were the same for Comparative Sample 1 and Sample 1, Comparative Sample 2 and Sample 2, and Comparative Sample 3 and Sample 3. The results are shown in Table 4.

  In Comparative Sample 1 and Comparative Sample 3, “second” was greater than 1.5 times after 120 hours, and in Comparative Sample 2, “second” was greater than 1.5 times after 240 hours. Thus, Comparative Samples 1 to 3 failed before 960 hours had passed.

  Therefore, according to the present embodiment, the electrical resistance value between the first terminal portion 29 and the terminal pattern 13 (13a, 13b) and the electrical resistance value between the second terminal portion 31 and the terminal pattern 13 (13c, 13d). Since the resistance value is stabilized, the reliability of electrical connection between the pair of sheets 3 and 5 of the touch panel 1 and the flexible connector 7 can be improved.

  As described above, according to the present embodiment, the reliability of connection (mechanical and electrical connection) between the pair of sheets 3 and 5 of the touch panel 1 and the flexible connector 7 can be improved.

It is a disassembled perspective view of the touchscreen which concerns on this embodiment. It is an enlarged plan view of the flexible connector which concerns on this embodiment. It is sectional drawing of the A1-A2 cross section of the flexible connector shown in FIG. 2, B1-B2 cross section, and C1-C2 cross section. In this embodiment, it is an expanded sectional view of the crimping | compression-bonding area | region at the time of crimping | bonding a pair of sheet | seat and a flexible connector.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Touch panel, 3,5 ... Sheet, 7 ... Flexible connector, 9 ... Transparent resistive film, 11 ... Electrode pattern, 13, 13a, 13b, 13c, 13d ... Terminal pattern 15 ... conductive pattern, 21 ... insulating film, 23 ... first metal wiring pattern, 25 ... second metal wiring pattern, 27 ... wiring pattern, 29 ... first DESCRIPTION OF SYMBOLS 1 terminal part, 31 ... 2nd terminal part, 33 ... Metal pattern, 35 ... One end of flexible connector 7, 37 ... The other end of flexible connector 7, 41 ... Insulating film One surface of 21, 43... Transparent protective film, 45... Plating layer, 47... The other surface of insulating film 21, 49. ..Transparent protective film, 55 Notches, 57, 59... Anisotropic conductive adhesive member, 61... Metal powder-containing film, R1... Crimping area, R2... Forming area of transparent protective film 43, R3. 53 formation region, P ... pressure

Claims (4)

An electrode pattern and a terminal pattern electrically connected thereto are formed, and a pair of sheets disposed opposite to each other;
A touch panel having a crimping region sandwiched between the pair of sheets and crimped thereto, and a flexible connector electrically connected to the terminal pattern of the pair of sheets in the crimping region,
The flexible connector is
An insulating film;
First and second metal wiring patterns formed on one surface of the insulating film;
A first terminal portion formed on and electrically connected to the first metal wiring pattern in the crimp region;
A contact portion formed on the other surface of the insulating film and electrically connected to the second metal wiring pattern at a contact portion provided on the insulating film, and having the same thickness as the first terminal portion. A wiring pattern having two terminal portions in the crimping region;
A metal pattern formed on one surface of the insulating film so as to face the second terminal portion, and having the same thickness as the first metal wiring pattern,
Used for crimping the pair of sheets and the flexible connector in the crimping region, electrically connecting the first terminal part and one terminal pattern of the pair of sheets, and the second terminal part An anisotropic conductive adhesive member that electrically connects the other terminal pattern of the pair of sheets. The flexible connector further includes:
A first plating layer formed between the first metal wiring pattern and the first terminal portion;
The touch panel according to claim 1, further comprising: a second plating layer formed on the metal pattern and having the same thickness as the first plating layer. The touch panel according to claim 1, wherein the metal pattern is made of the same material as the first and second metal wiring patterns. A flexible connector having a crimping region in which an anisotropic conductive adhesive member is disposed,
An insulating film;
First and second metal wiring patterns formed on one surface of the insulating film;
A first terminal portion formed on and electrically connected to the first metal wiring pattern in the crimp region;
A contact portion formed on the other surface of the insulating film and electrically connected to the second metal wiring pattern at a contact portion provided on the insulating film, and having the same thickness as the first terminal portion. A wiring pattern having two terminal portions in the crimping region;
A flexible connector comprising: a metal pattern formed on one surface of the insulating film so as to face the second terminal portion and having the same thickness as the first metal wiring pattern.

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