JP2008060296A - Electronic equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide electronic equipment having a connector using a photo-setting ACF, and having the excellent reliability of the connector. <P>SOLUTION: The electronic equipment related to a first mode has an insulating substrate 102 forming an electrode 113, and an external terminal 114 being formed on the end side of the insulating substrate 102 and having a metallic layer connected to the electrode 113. The electronic equipment further has a connecting substrate 116 having a connecting terminal 117 connected to the external terminal 114 through a photo-setting anisotropic conductive material 115. In the electronic equipment, the external terminal 114 and the connecting terminal 117 are arranged so as to be superposed, and a non-superposing region not superposed to the metallic layer 114b for the external terminal is formed to the whole or a part of the peripheral region of the connecting terminal 117. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an electronic device, and more particularly to an electronic device using a photocurable anisotropic conductive material.

  A display panel such as a liquid crystal display device or an organic EL (Electro Luminescence) display device is connected with a flexible substrate on which a drive circuit or the like is mounted in order to supply a power supply voltage, a display signal, and the like from the outside. As a method of connecting the display panel and the flexible substrate, generally, an external terminal provided at an end of a glass substrate constituting the display panel and a connection terminal of the flexible substrate are connected to an anisotropic conductive film (ACF: Anisotropic). A method of thermocompression bonding via a conductive film) is used (for example, see Patent Document 1).

  Specifically, the ACF is disposed on the connection terminal of the flexible substrate, and the external terminal of the glass substrate and the connection terminal of the flexible substrate are aligned and thermocompression bonded. Thereby, the external terminal of the glass substrate is electrically connected to the connection terminal of the flexible substrate, and the display panel and the flexible substrate are physically fixed.

As the ACF binder to be thermocompression bonded, a thermosetting compound is used. In recent years, the use of a photocurable compound that does not require heating has been studied. Thereby, the manufacturing process of a display panel can be simplified. In this case, conductive particles are mixed into the ultraviolet curable compound to obtain an anisotropic conductive material.
JP-A-11-135909

  When photo-curing ACF is used, the ACF is placed on the connection terminal of the flexible substrate, the external terminal of the glass substrate and the connection terminal of the flexible substrate are aligned and pressed, and the opposite glass substrate surface The ACF is cured by irradiating light.

  Here, since the external terminal of the glass substrate is usually made of a laminate in which a metal layer such as Cu is formed on a transparent conductive film such as ITO, it does not transmit light. Therefore, the portion of the ACF sandwiched between the external terminal of the glass substrate and the connection terminal of the flexible substrate remains uncured. Therefore, there is a problem that peeling occurs between the external terminal of the glass substrate and the connection terminal of the flexible substrate, resulting in poor connection.

  The present invention has been made in view of the above, and an object of the present invention is to provide an electronic device having a connection portion using a photocurable ACF and having excellent reliability of the connection portion. .

  An electronic device according to a first aspect of the present invention includes an insulating substrate on which an electrode is formed, an external terminal formed on an edge of the insulating substrate and including a metal layer connected to the electrode, and the external terminal. A connection substrate having a connection terminal connected via a photocurable anisotropic conductive material, the external terminal and the connection terminal are arranged so as to overlap, and the entire peripheral area of the connection terminal or one A non-overlapping region that does not overlap with the metal layer of the external terminal is formed in the portion. Thereby, the reliability of the connection part between the insulating substrate and the connection substrate connected via the photocurable ACF can be improved.

  The electronic device according to a second aspect of the present invention is characterized in that, in the electronic device described above, the non-overlapping region is formed in the entire peripheral region of the connection terminal. Thereby, the reliability of the connection part of the insulating substrate and connection board which were connected via the photocurable ACF reliably can be improved.

  An electronic device according to a third aspect of the present invention is the above electronic device, wherein the external terminal is formed of a laminate of a transparent conductive layer and a metal layer, and the metal layer is provided at a plurality of locations in each of the external terminals. It is characterized by being divided and arranged. Thereby, the reliability of the connection portion between the insulating substrate and the connection substrate connected via the photocurable ACF can be further improved.

  According to the present invention, it is possible to provide an electronic device having a connection portion using photocurable ACF and having excellent reliability of the connection portion.

  Hereinafter, embodiments to which the present invention can be applied will be described. The following description explains the embodiment of the present invention, and the present invention is not limited to the following embodiment.

Embodiment 1 FIG.
A first embodiment of the present invention will be described with reference to FIG. FIG. 1 is a cross-sectional view illustrating an example of an electronic apparatus according to this embodiment. In this embodiment, a liquid crystal display panel 100 will be described as an example of an electronic device. As shown in FIG. 1, the liquid crystal display panel 100 is a full-dot STN type liquid crystal panel, and displays an image according to a signal input from the outside. As shown in FIG. 1, the liquid crystal display panel 100 has a configuration in which a liquid crystal layer 111 is sandwiched between a first substrate 101 and a second substrate 102 which are transparent insulating substrates made of glass, resin, or the like arranged to face each other. have. The first substrate 101 and the second substrate 102 are fixed by a sealing material 103.

  A signal electrode 112 and a scanning electrode 113 are formed on the opposing surfaces of the first substrate 101 and the second substrate 102, respectively. A plurality of signal electrodes 112 are formed on the first substrate 101 at regular intervals in the row direction. A plurality of scanning electrodes 113 are formed on the second substrate 102 at regular intervals in the column direction so as to intersect with the signal electrodes 112. The display area is composed of a plurality of pixels, and the intersection of the signal electrode 112 and the scanning electrode 113 corresponds to the pixel. These electrodes are formed of a transparent conductive film such as ITO (Indium Tin Oxide), IZO (Indium Zinc Oxide), and ITZO (Indium Tin Zinc Oxide). Note that, contrary to the above, a scan electrode may be formed on the first substrate 101 and a signal electrode may be formed on the second substrate 102.

  The scanning electrode 113 formed on the second substrate 102 is extended to the end of the second substrate 102 which is a frame region for inputting or outputting a signal. At the end of the second substrate 102, an external terminal metal layer 114 b made of Cu, Al, Cr, Mo, Ti or the like is laminated on the external terminal transparent conductive film 114 a extending from the scanning electrode 113. Thus, an external terminal 114 having a laminated structure is formed. Thereby, contact resistance with a connection board | substrate can be reduced.

  The external terminal is connected to an FPC (Flexible Printed Circuit) 116 that is a connection substrate via a photocurable ACF 115. More specifically, the external terminal 114 is connected to the connection terminal 117 of the FPC 116. As the photocurable resin, for example, a commercially available epoxy resin-based resin can be used. Specific examples include LX-3014 manufactured by Henkel Japan.

  FIG. 2 is a perspective plan view showing the positional relationship between the metal layer 114 b of the external terminal and the connection terminal 117 when viewed from the normal direction of the main surface of the second substrate 102. Conventionally, the metal layer 114b of the external terminal and the connection terminal 117 are formed so as to substantially coincide with each other. However, as described above, since the region where the external terminal metal layer 114b is formed cannot transmit light, the ACF on the region remains uncured. For this reason, there is a problem that separation occurs between the external terminal 114 and the connection terminal 117, resulting in poor connection.

  Therefore, in the present invention, as shown in FIG. 2, the region where the metal layer 114 b of the external terminal of the second substrate 102 is formed and the region where the connection terminal 117 of the connection substrate is formed are divided into the second substrate 102. When viewed from the normal direction of the main surface, a non-overlapping region that does not overlap with the metal layer 114b of the external terminal is formed in the entire peripheral region of the connection terminal 117. That is, the entire external terminal 114 overlaps with the connection terminal 117, but the peripheral area of the connection terminal 117 is a non-overlapping area. With such a configuration, the photocurable ACF is cured at the peripheral portion of the connection terminal 117 and is firmly bonded to the transparent conductive film 114a of the external terminal, and the connection terminal 117 and the external terminal 114 are peeled off. There is no starting point to do. Therefore, the reliability of the connection portion between the external terminal 114 and the connection terminal 117 can be improved. The non-overlapping region may be formed only in a part of the peripheral region of the connection terminal 117, but is preferably formed in the entire peripheral region as shown in FIG.

  Further, a non-overlapping region formed in the entire peripheral region of the connection terminal 117 communicates with the inner region of the connection terminal 117. In other words, the metal layer 114b of the external terminal is preferably divided into a plurality of locations in each external terminal 114. With such a configuration, the reliability of the connection portion between the external terminal 114 and the connection terminal 117 can be further improved. Specifically, the light transmittance becomes uniform, and the connection can be made stronger. However, the contact resistance of the connection portion increases as the area of the formation region of the external terminal 114 decreases. The matrix panel 120 is not limited to a simple matrix type, and an active matrix type liquid crystal display panel using a TFT (Thin Film Transistor) may be used.

  Next, a method for manufacturing the liquid crystal display panel 100 according to the present embodiment will be described. FIG. 3 is a flowchart of the manufacturing method of the liquid crystal display panel 100 according to the present embodiment.

  First, a transparent conductive film made of ITO or the like is formed on one surface of the first substrate 101 and the second substrate 102 by a vacuum deposition method, a sputtering method, or the like. Each transparent conductive film is patterned by a photolithography process or the like to form a signal electrode 112 on the first substrate 101 and a scanning electrode 113 on the second substrate 102 (step S101).

  Next, a metal layer for external terminals is formed on the transparent conductive film by a vacuum deposition method, a sputtering method, or the like. Each metal layer is patterned by a photolithography process or the like to form a metal layer 114b of an external terminal. Thus, the external terminal 114 made of a laminate of the transparent conductive film 114a for the external terminal and the metal layer 114b for the external terminal is formed on the second substrate 102 (step S102). Here, as shown in FIG. 2, the region where the metal layer 114 b of the external terminal of the second substrate 102 is formed and the region where the connection terminal 117 of the connection substrate is formed are the main surface of the second substrate 102. When viewed from the normal line direction, a non-overlapping region that does not overlap with the metal layer 114 b of the external terminal is formed in the entire peripheral region of the connection terminal 117. Further, it is preferable that a non-overlapping region formed in the entire peripheral region of the connection terminal 117 is communicated in the internal region of the connection terminal 117. In other words, the metal layer 114b of the external terminal is preferably divided into a plurality of locations in each external terminal 114. Light can be transmitted in this non-overlapping region.

  Next, the signal electrode 112 and the scanning electrode 113 are opposed to each other, and the first substrate 101 and the second substrate 102 are bonded to each other with the sealant 103 interposed therebetween. A liquid crystal is filled in the formed space, and the liquid crystal display panel 100 is formed. Here, the filled liquid crystal constitutes the liquid crystal layer 111. (Step S103).

  Next, the external terminal 114 and the FPC 116 on the second substrate 102 are bonded to each other through a photocurable ACF 115. Here, the ACF 115 is cured by irradiating light from the opposite side of the second substrate 102 while applying pressure from above the FPC 116. As a result, the external terminal 114 and the FPC 116 on the second substrate 102 are fixed and electrically connected. (Step S104).

  Specifically, a photocurable ACF 115 is disposed on the external terminal 114 on the second substrate 102, and the FPC 116 is disposed thereon. Here, the connection terminal 117 of the FPC 116 is arranged on the metal layer 114b of the external terminal so as to have the positional relationship shown in FIG. The entire region where the ACF 115 is formed is pressurized from above the FPC 116, and at the same time, light such as ultraviolet rays is irradiated from the opposite side of the second substrate 102, that is, the lower side, to cure the ACF 115. As the ACF 115 is cured, the external terminal 114 and the FPC 116 on the second substrate 102 are fixed and electrically connected. This vertical relationship may be reversed.

  Here, the region where the metal layer 114 b of the external terminal of the second substrate 102 was formed and the region where the connection terminal 117 of the connection substrate was formed were viewed from the normal direction of the main surface of the second substrate 102. In this case, the ACF is uncured in the region where the external terminal metal layer 114b is formed, but in the non-overlapping region where the connection terminal 117 is formed and the external terminal metal layer 114b is not formed, The connection terminal 117 and the transparent conductive film 114a of the external terminal are firmly bonded by the cured ACF. Therefore, there is no starting point where the connection terminal 117 and the external terminal 114 are separated, and the reliability of the connection portion between the external terminal 114 and the connection terminal 117 can be improved.

  The present invention provides not only a display device such as a liquid crystal display device and an organic EL display device, but also an electronic device in which an electrode is formed on an insulating substrate and an FPC is connected to the electrode through a photocurable ACF. The same applies to any device.

It is sectional drawing which shows the structure of the electronic device which concerns on embodiment. It is a plane transmission figure which shows the positional relationship of the external terminal of the insulated substrate which concerns on embodiment, and the connection terminal of FPC. It is a flowchart explaining the manufacturing method of the electronic device which concerns on embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Liquid crystal display panel 101 1st board | substrate 102 2nd board | substrate 103 Sealing material 111 Liquid crystal layer 112 Signal electrode 113 Scan electrode 114 External terminal 114a External conductive film 114b External terminal metal layer 115 ACF
116 FPC
117 connection terminal

Claims (3)

An insulating substrate on which electrodes are formed;
An external terminal including a metal layer formed on an edge of the insulating substrate and connected to the electrode;
A connection board having a connection terminal connected to the external terminal via a photocurable anisotropic conductive material,
Arranged so that the external terminal and the connection terminal overlap,
An electronic apparatus in which a non-overlapping region that does not overlap the metal layer of the external terminal is formed in the whole or a part of the peripheral region of the connection terminal.   The electronic apparatus according to claim 1, wherein the non-overlapping region is formed in the entire peripheral region of the connection terminal.   3. The electron according to claim 1, wherein the external terminal includes a laminate of a transparent conductive layer and a metal layer, and the metal layer is divided and arranged at a plurality of locations in each of the external terminals. machine.

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