JP2007322591A - Image display - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a display which has terminales for checking a crushed state of conductive particles in an ACF while reducing the electric resistance of a transparent electrode. <P>SOLUTION: The display has a transparent substrate 1, and one or more terminals 21 extending in stripes on the transparent substrate 1. The terminal 21 is composed of a transparent layer 3 and an opaque layer 4 stacked on the transparent layer 3 and connected to other terminals 6 through the ACF5 which is stacked on the terminal 21. The opaque layer 4 is formed to partly expose the transparent layer 3 to the ACF5. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a structure for connecting a terminal portion of a display panel used in a display device such as a liquid crystal display device or an organic EL display device and other electric components using an anisotropic conductive film, and in particular, the terminal portion described above. The present invention relates to a case where the transparent electrode and the metal protective film are used.

  In a display panel used in such a display device such as a liquid crystal display device or an organic EL display device, it is necessary to make the display region transparent. For example, a transparent electrode such as an ITO electrode is often used. . In addition, a method using an anisotropic conductive film (hereinafter abbreviated as ACF), for example, as in the method described in Patent Document 1, is known for connecting the ITO electrode and an external electrical component. ing. ACF is a film formed by diffusing conductive particles in an adhesive insulating resin. When the ACF is sandwiched between facing terminals and pressed in the thickness direction of the ACF so that the terminals approach each other, the conductive particles are crushed in the thickness direction of the ACF so that the facing terminals are electrically connected to each other. become. On the other hand, in the direction orthogonal to the thickness direction of the ACF, the conductive particles are separated from each other and insulated by an insulating resin. For this reason, when a plurality of sets of facing terminals are arranged in parallel, adjacent sets of terminals do not conduct. As described above, the ACF can be bonded by conducting a pair of terminals facing each other only in the thickness direction, and is widely used.

  In FIG. 7, the top view of the conventional general display apparatus X is shown. As shown in FIG. 7, the display device X includes a transparent glass substrate 91, a transparent ITO electrode formed on the glass substrate 91, and a part of the ITO electrode along a vertical direction in FIG. 7. And a terminal group 92 composed of a plurality of terminals formed by covering with a metal film. In this terminal group 92, the terminals are arranged in parallel along the left-right direction in FIG. 7 at a predetermined interval, and are connected to a flexible wiring board connected to a driving IC chip, a power supply device, etc. via an ACF. It is connected. In general, the conductivity of the ITO electrode is inferior to that of a metal wiring such as Al. Therefore, by configuring the terminal group 92 with an ITO electrode and an Al layer covering the ITO electrode, the electric resistance in the terminal group 92 is reduced. Can be suppressed.

  However, when pressurizing the terminals sandwiching the ACF, the amount of pressurization may be insufficient depending on the position depending on the inclination of the pressurizing device, and the conductive particles in the ACF may not be sufficiently crushed. If the conductive particles are not sufficiently crushed, the ACF does not conduct in the thickness direction, and the terminal group 92 and the flexible wiring board may not be conducted, resulting in a defective product. If the ITO electrode is covered with a non-transparent Al layer, it is not possible to confirm the collapse state of the conductive particles in the ACF from the outside through the glass substrate 91. Therefore, until the energization test is performed after the display device X is actually assembled. The defective product as described above could not be found.

JP 2000-187238 A

  The present invention has been conceived under the circumstances described above, and provides a display device having a terminal portion that can confirm the degree of collapse of conductive particles in the ACF while reducing the electrical resistance of the transparent electrode. Is an issue.

  In order to solve the above problems, the present invention employs the following technical means.

  The display device according to the present invention includes a transparent substrate and one or more terminal portions formed to extend in a strip shape on the transparent substrate, and the terminal portions are laminated on the transparent layer. A non-transparent layer, and the terminal portion is electrically connected to another terminal via the ACF, and a part of the transparent layer is exposed to the ACF. The opaque layer is formed.

  According to such a configuration, in the portion where the transparent layer is exposed from the opaque layer, the transparent layer and the ACF are directly laminated in the thickness direction. For this reason, it is possible to visually check the inside of the ACF through the transparent substrate to confirm the collapse of the conductive particles inside. Further, the degree of collapse of the conductive particles in the opaque layer can be estimated from the degree of collapse of the conductive particles in the transparent layer.

  In a preferred embodiment, the opaque layer is formed with one or more through holes reaching the transparent layer and the ACF. According to such a configuration, the ACF laminated on the transparent layer can be seen through the transparent substrate in the through hole. If the conductive particles in the ACF that can be seen through the through-holes are sufficiently crushed, it is presumed that the conductive particles are sufficiently crushed even in portions where the through-holes are not formed. In addition, since the through hole is surrounded by other portions of the opaque layer, the conductive particles do not move out of the range of the terminal portion when pressure is applied to the ACF. For this reason, in this through-hole, the pressurization state in the said opaque layer can be grasped | ascertained more correctly.

  In a preferred embodiment, each of the pair of terminal portions is provided with a plurality of the terminal portions arranged in a direction orthogonal to the extending direction, and separated in the direction in which the plurality of terminal portions are arranged. Are formed with a pair of the above-mentioned through holes that are separated in the direction in which these terminal portions extend. According to such a structure, the said through-hole is arrange | positioned at least four places corresponding to the four corners of a rectangle, and it is possible to confirm the crushing state of the electroconductive particle in each position. . For this reason, for example, it is easy to find the collapse of the conductive particles due to, for example, the inclination of the pressurizing device, and it can be optically confirmed without actually energizing in the manufacturing process. It is also possible to correct the tilt.

  Other features and advantages of the present invention will become more apparent from the detailed description given below with reference to the drawings.

  FIG. 1 shows a plan view of the display device A1 according to the first embodiment of the present invention. The display device A1 is an organic EL display device, for example, and includes a glass substrate 1 and a terminal group 2 as shown in FIG. Although not shown in FIG. 1, the display device A1 is connected to a counter substrate facing the glass substrate 1, a flexible wiring substrate connected to the terminal group 2 via the ACF, and the flexible wiring substrate. A power supply device, a driving IC, and the like are provided.

  An anode layer is formed on the glass substrate 1, and a cathode layer is formed on the counter substrate. The anode layer is formed by arranging a plurality of linear electrodes extending in the vertical direction in FIG. 1 so as to be arranged in parallel in the horizontal direction in FIG. On the other hand, the cathode layer includes a plurality of linear electrodes extending in a direction orthogonal to the anode layer along a direction orthogonal to the direction in which the anode layers are arranged. Further, an organic EL layer is sandwiched between the anode layer and the cathode layer, and the organic EL layer is caused to emit light by applying a voltage between the two layers at the intersection of the anode layer and the cathode layer. be able to. In order to extract light emitted from the organic EL layer to the outside, the anode layer is made of ITO, which is a transparent and conductive material.

  FIG. 2 shows an enlarged view of the terminal group 2. However, in FIG. 2, the ACF and the flexible wiring board are omitted. Further, FIG. 3 shows a cross-sectional view taken along line III-III in FIG. As shown in FIG. 2, the terminal group 2 includes a plurality of terminal portions 21 arranged in parallel at a predetermined interval.

  As shown in FIGS. 2 and 3, the terminal portion 21 is formed in a strip shape extending from the inside of the display device A <b> 1 to the outside, and includes the transparent electrode layer 3 and the metal layer 4. The terminal portion 21 is connected to the counter terminal 6 formed on the flexible wiring board with the ACF 5 interposed therebetween.

  The transparent electrode layer 3 is extended from the linear electrode which comprises the said anode layer and the said cathode layer, and was formed on the glass substrate 1 according to the shape of the terminal part 21, as shown in FIG. Is. Since the anode layer is formed on the glass substrate 1, each electrode constituting the anode layer is directly extended to the terminal portion 21 and formed on the transparent electrode layer 3. On the other hand, each electrode constituting the cathode layer is connected from the counter substrate to a transparent wiring (not shown) on the glass substrate 1 through, for example, a through hole. These transparent wirings (not shown) extend to the terminal portion 21 and are formed on the transparent electrode layer 3 in the same manner as the anode layer. In order to unify the material of the transparent electrode layer 3, it is preferable that the transparent wiring (not shown) is made of the same ITO as the anode layer.

  The metal layer 4 is formed of a highly conductive material such as Al, for example, and is formed so as to cover a predetermined region of the transparent electrode layer 3 closer to the inside of the display device A1. The metal layer 4 is formed to compensate for the electrical conductivity of the ITO forming the transparent electrode layer 3 which is inferior to that of Al or the like. The thickness of the metal layer 4 is preferably less than half the thickness of the transparent electrode layer 3.

  The ACF 5 is formed in the form of a film by diffusing elastically deformable conductive particles 5b in an adhesive insulating resin 5a. The ACF 5 covers the entire terminal group 2, and the flexible wiring board is installed thereon. A plurality of opposing terminals 6 are arranged in parallel on this flexible wiring board, and correspond to the terminal portions 21 arranged in parallel. When pressure is applied between the opposing terminal 6 and the terminal portion 21, as shown in FIG. 3, the conductive particles 5b are pressed and elastically deformed into a crushed shape, and between the opposing terminal 6 and the terminal portion 21. Is conducted. Further, the opposing terminal 6 and the terminal portion 21 are physically bonded by the adhesive insulating resin 5a.

  The effects of the display device A1 will be described below.

  As described above, the terminal portion 21 of the display device A1 is partially covered with the metal layer 4 as shown in FIG. 3, but the ACF 5 is directly laminated on the transparent electrode layer 3 in the other portions. Yes. For this reason, in the area where the metal layer 4 is not formed, the inside of the ACF 5 can be visually or optically photographed through the glass substrate 1 and the transparent electrode layer 3. Therefore, for example, when the flexible wiring board is bonded to the terminal portion 21, it can be confirmed whether or not the conductive particles 5b inside the ACF 5 are crushed from the outside. If the conductive particles 5b are kept in a spherical shape without being crushed, there is a possibility that the terminal portion 21 and the counter terminal 6 are not conductive. If the conductive particles 5b are crushed, the conductive particles 5b are opposed to the terminal portion 21. Since both terminals 6 are in contact, both are conducting. Further, since the gap between the metal layer 4 and the counter terminal 6 is narrower than the gap between the transparent electrode layer 3 and the counter terminal 6, if the conductive particles 5b are crushed in a range that can be seen through the transparent electrode layer 3, It may be considered that the conductive particles 5 b are crushed even in the range covered with the metal layer 4.

  Moreover, since a part of the transparent electrode layer 3 is covered with the metal layer 4 excellent in electrical conductivity, the electrical resistance of the terminal group 2 is kept relatively small. Thus, the display device A1 is configured to be able to optically check the inside of the ACF 5 while suppressing the electrical resistance in the terminal group 2. For this reason, it is possible to easily confirm whether or not the terminal group 2 and the flexible wiring board are conductive without actually energizing. Therefore, since it is possible to check the degree of collapse of the conductive particles 5b in the ACF 5 as appropriate during the manufacturing process, it is possible to quickly check whether there is a defect in the manufacturing apparatus if a defect occurs. The production line can be stabilized.

  FIG. 4 shows an enlarged view of the vicinity of the terminal group 2 of the display device A2 according to the second embodiment of the present invention. Further, FIG. 5 shows a cross-sectional view taken along the line V-V in FIG.

  As shown in FIG. 4, the terminal portion 21 of the display device A2 is entirely covered with the metal layer 4 except for the through holes 4a, and the other configuration is the same as that of the display device A1. As shown in FIG. 5, the through hole 4 a is a through portion along the thickness direction formed in the metal layer 4 so that the transparent electrode layer 3 is exposed to the ACF 5. In this through hole 4a, since the ACF 5 is directly laminated on the transparent electrode layer 3, the state of the conductive particles 5b in the ACF 5 can be confirmed through the glass substrate 1.

  As shown in FIG. 4, the through-hole 4 a is formed near both ends in the terminal portion 21 in the terminal group 21 in the parallel direction of the terminal portion 21 in the direction in which the terminal portion 21 extends in a strip shape. Thus, since the through holes 4a are formed in the vicinity of the four apexes of the rectangle surrounding the terminal group 2, a necessary confirmation operation can be performed efficiently. That is, if the conductive particles 5b are crushed in each of the four through holes 4a arranged in this way, it can be estimated that the entire terminal group 2 is conductive without any defects. As a cause that the conductive particles 5b in the ACF 5 sandwiched between the terminal portion 21 and the counter terminal 6 are not sufficiently crushed, for example, it is assumed that the processing device is inclined and the pressurization amount is insufficient depending on the position. The Providing the through holes 4a at positions corresponding to the four corners of the rectangle is suitable for finding such a defect.

  Further, in the terminal portion 21 of the display device A2, since the area of the metal layer 4 covering the transparent electrode layer 3 is larger than that of the terminal portion 21 of the display device A1, the wiring resistance in the terminal group 2 is further reduced. ing. For this reason, further reduction in resistance can be expected in the display device A2. Further, in the through hole 4 a, the portion where the ACF 5 is directly laminated on the transparent electrode layer 3 is surrounded by the metal layer 4. For this reason, in the through-hole 4a, when pressure is applied between the terminal portion 21 and the counter terminal 6, the conductive particles 5b are not pushed by the pressure without being crushed and are not moved. Confirmation work can be performed.

  FIG. 6 shows an enlarged view of the vicinity of the terminal group 2 of the display device A3 according to the third embodiment of the present invention. In the display device A3, almost the entire surface of the transparent electrode layer 3 is covered with the metal layer 4, and a through hole 4a is formed at a predetermined position. The display device A3 is the same as the display device A2 except for the arrangement of the through hole 4a. .

  In the terminal group 2 of the display device A3, as shown in FIG. 6, the terminal portions 21 whose entire surfaces are covered with the metal layer 4 and the terminal portions 21 in which the through holes 4a are formed in the center are alternately arranged. . According to such an arrangement of the through holes 4a, it is possible to check in detail the state of collapse of the conductive particles 5b in the ACF 5 along the direction in which the terminal portions 21 are arranged in parallel. Such an arrangement of the through holes 4a in the display device A3 is such that, for example, when the length of the terminal portion 21 in the longitudinal direction is relatively short and the number of the parallel portions 4 is large, the ACF 5 This is advantageous when the pressure applied to the is easily biased.

  The display device according to the present invention is not limited to the display device in the above-described embodiment. For example, in the above-described embodiment, a passive matrix organic EL display device is taken as an example, but an active matrix organic EL display device, a liquid crystal display device, and the like can also be applied. That is, the present invention is applied to any display device having a configuration in which a transparent electrode layer is provided on a transparent substrate, and a connection terminal extending from the transparent electrode layer is covered with a metal layer and connected to another terminal via an ACF. Is available. Further, in the display devices A2 and A3, the rectangular through-hole 4a is shown, but it may be circular or elliptical, and when the metal film 4 is partly cut out without being hole-shaped, etc. Are also within the scope of the present invention.

1 is a plan view of a display device according to a first embodiment of the present invention. FIG. 2 is an enlarged view of the vicinity of a terminal portion 2 in FIG. 1. It is sectional drawing which follows the III-III line of FIG. It is a top view of the display apparatus which concerns on 2nd Embodiment of this invention. It is sectional drawing which follows the VV line of FIG. It is a top view of the display apparatus which concerns on 3rd Embodiment of this invention. It is a top view of the conventional display apparatus.

Explanation of symbols

A1, A2, A3 Display device 1 Glass substrate 2 Terminal group 21 Terminal portion 3 Transparent electrode layer 4 Metal layer 4a Through hole 5 ACF
5a Insulating resin 5b Conductive particle 6 Opposite terminal

Claims (3)

A transparent substrate; and one or more terminal portions formed on the transparent substrate so as to extend in a strip shape. The terminal portion includes a transparent layer and an opaque layer laminated on the transparent layer. The terminal portion is a display device that is conductively connected to other terminals via an anisotropic conductive film,
The display device, wherein the opaque layer is formed so that a part of the transparent layer is exposed to the anisotropic conductive film.   The display device according to claim 1, wherein the opaque layer has one or more through holes reaching the transparent layer and the anisotropic conductive film.   Each of the pair of terminal portions separated in the direction in which the plurality of terminal portions are arranged is provided with a plurality of the terminal portions arranged in a direction orthogonal to the extending direction. The display device according to claim 2, wherein a pair of the through holes spaced apart in the extending direction are formed.

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