JP2005292505A - Display panel, IC chip, and manufacturing method thereof - Google Patents

Abstract

An object of the present invention is to provide a display panel that can continue normal operation even when a chip is unable to follow the deformation of the panel substrate and breaks when adopting a driving IC for COG connection. There is.
A display panel according to the present invention is characterized in that a driving IC chip 3 having a circuit for driving a display portion is mounted on a panel substrate, wherein the driving IC chip is provided. A groove 60 is formed on the surface of the circuit 3, and the circuit is divided into a first part 3 a and a second part 3 b which are electrically separated by the groove 60. The connection wiring 33 for electrically connecting the one part 3a and the second part 3b is formed.
[Selection] Figure 5

Description

  The present invention relates to a display panel, and more particularly to a display panel in which a driving IC chip is directly mounted on a substrate constituting the display panel.

  In recent years, the market of flat display panels (FPD) has been expanding rapidly, and in particular, liquid crystal display panels (LCD) have become mainstream of flat display panels due to their low power consumption and display quality. A wide variety of liquid crystal display panels have been put into practical use, from small products such as mobile phones to large products such as TVs.

  Such a liquid crystal display panel includes a glass panel (panel substrate) on which a display unit is provided and a driving IC for driving the display unit. The glass panel and the driving IC are electrically connected. As this connection method, a TCP (TAPE Carrier Package) in which the driving IC is mounted on a tape carrier film in which copper wiring is formed on a polyimide resin thin film base or the like is used. A method and a COG (Chip On Glass) system in which a driving IC is directly mounted on a liquid crystal display device are known.

  The COG method is easier to reduce the thickness and weight than the TCP method, and can reduce the cost by eliminating the need for a tape carrier film. Therefore, the COG method has been widely used in recent liquid crystal display panels. .

  As a connection method of this COG method, an electrode is formed on a driving IC with solder and the solder is melted and connected, or an electrode is formed with a metal such as gold, and a conductive paste or an insulating adhesive. A method of connecting with an anisotropic conductive adhesive in which conductive particles are diffused and mixed is known.

  In particular, according to the connection method using the anisotropic conductive adhesive, the connection pitch depends only on the size of the electrodes of the driving IC, and the insulating adhesive is filled between the electrodes. Therefore, since it has advantages such as ensuring sufficient insulation between the electrodes, the connection method using the anisotropic conductive adhesive has become the mainstream in the COG system.

  However, the display panel manufactured by the COG method has a problem that when an external stress is applied, the drive IC chip is cracked and display cannot be performed. This is particularly noticeable in small modules used for mobile phones and the like. The reason for this is that the glass thickness has been reduced with the reduction in size and weight of the module, and it is easy for glass deformation to occur when an impact is applied to the module, and the COG chip cannot follow the glass deformation and break. It will lead to. If the chip is broken in this way, the wiring inside the driving IC is cut, so that the driving IC becomes inoperable, and as a result, the function as the display panel is lost.

  Patent Document 1 describes that the concentration of stress on the connection portion is alleviated by forming a plurality of grooves in the driving IC chip. However, the one described in this Patent Document 1 is effective in relaxing the stress on the connection part due to thermal expansion, thermal contraction, impact, etc., but when a larger deformation stress occurs, The driving IC is broken along the groove portion thinner than the portion, and the driving IC becomes inoperable.

Further, Patent Document 2 describes a method in which a plurality of drive IC chips are connected by an inner lead wiring to form a single tape carrier package. In the thing of this patent document 2 place, when a stress generate | occur | produces, even if a chip | tip breaks among several IC chips for driving fortunately, although a function is not lost, the generation | occurrence | production location of a crack is In the case of the circuit element portion of the driving IC chip, it becomes inoperable after all.
JP-A-2-240942 JP-A-11-150227

  The present invention has been made in view of the above-mentioned problems, and the problem of the present invention is that when a driving IC for COG connection is employed, the chip cannot follow the deformation of the panel substrate and has cracked. Even in such a case, it is to provide a display panel capable of continuing normal operation.

  The present invention has been made to solve the above-described problems, and a display panel according to the present invention is characterized in that a driving IC chip having a circuit for driving a display unit is mounted on a panel substrate. A panel having a groove formed on a circuit surface of the driving IC chip and divided into a first part and a second part in which the circuit is electrically separated by the groove; Is that a connection wiring for electrically connecting the first part and the second part is formed.

  By adopting the above configuration, when a stress is applied to the panel substrate of the display panel and the panel substrate is bent so that the driving IC cannot follow, the driving IC has a groove on the circuit surface. The IC chip is cracked from this groove. At this time, since the broken circuit (the first part and the second part) is electrically connected by the connection wiring of the panel substrate, operation problems occur even if the driving IC chip is cracked in the groove. Will not.

  The IC chip according to the present invention is characterized in that the IC chip is provided so as to be mounted on another substrate and a circuit is formed, and a groove is formed on the surface of the circuit. The groove is divided into a first part and a second part where the circuit is electrically separated by the groove, and the first part and the second part are connected wirings of the board when mounted on the other board. It is in the point provided so that it may be electrically connected by. Thus, by mounting this IC chip on another substrate on which connection wiring is formed, the same advantages as those of the display panel according to the present invention described above can be combined.

  A feature of the display panel manufacturing method according to the present invention is a method of manufacturing a display panel by mounting a driving IC chip having a circuit for driving a display unit on a panel substrate, wherein the driving is performed. A groove is formed on the circuit surface of the IC chip so that the circuit is electrically divided and divided into a first part and a second part, and the first part and the second part are formed by connection wiring formed on the panel substrate. The driving IC chip is mounted on the panel substrate so as to be electrically connected to the part. Also, the IC chip manufacturing method according to the present invention is characterized by a method of manufacturing an IC chip that is provided to be mounted on another substrate and on which a circuit is formed, wherein the circuit is formed. And a step of forming a groove on the surface of the circuit, the groove is formed so that the circuit is divided into a first part and a second part that are electrically separated, and the circuit is The first portion and the second portion are formed so as to be electrically connected by connection wiring of the substrate when mounted on another substrate. As a result, the display panel and the IC chip according to the present invention described above can be manufactured.

  In the present invention, it is preferable to adopt a configuration in which the groove of the driving IC chip is formed at the time of one step cutting of the step cut type dicing apparatus. As a result, it is not necessary to separately add a step of forming a groove, and manufacturing can be performed without increasing the number of processing steps.

  In the present invention, a groove is formed in the driving IC chip, and the first part and the second part separated by the groove are connected by the connection wiring of the panel substrate. For this reason, even when stress is applied to the panel and the driving IC chip is cracked by the groove, it operates normally and does not cause a display defect of the display panel. Further, if a step-cut type device is used as a driving IC chip dicing device, the step-type device can form the groove, and the cost increases due to an increase in the number of steps without increasing the number of steps. Can be suppressed.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic perspective view of the display panel of the present embodiment. FIG. 2 is a schematic plan view showing the overall configuration of the display panel of the embodiment. 3 is a sectional view taken along line XX in FIG. 2, and FIG. 4 is a sectional view taken along line YY in FIG. FIG. 5 is a schematic explanatory diagram for illustrating a wiring configuration of the display panel of the embodiment. FIG. 6 is a schematic explanatory view showing the relationship between the wafer and the circuit of the driving IC chip in the manufacturing method of the embodiment. 7A and 7B are explanatory diagrams for explaining a dicing method of the driving IC chip in the manufacturing method of the embodiment. FIG. 7A is a procedure for forming a groove in the first step, and FIG. 7B is a cutting in the second step. It is explanatory drawing of the procedure to perform.

  The liquid crystal display panel of the present embodiment is of an active matrix drive type, and as shown in FIG. 3, a pair of substrates 5 and 10 have a predetermined gap via a seal material 9, and in this gap The liquid crystal layer 8 is sandwiched. This substrate is composed of a light transmissive insulating substrate such as a glass plate or a plastic plate. As shown in FIGS. 1 and 2, the pair of substrates 5 and 10 is provided with the other substrate 10 larger than the one substrate 5, and the larger substrate 10 has a larger size than the smaller substrate 5. Also, IC chips 2 and 3 to be described later are mounted on the portion protruding from the plan view.

  One substrate 10 (hereinafter also referred to as “display substrate”) of the pair of substrates 5 and 10 includes a switching element such as a thin film transistor (hereinafter referred to as “TFT”) on the surface and the switching element. A plurality of connected pixel electrodes are formed in a matrix, and a plurality of scanning signal lines and data signal lines for driving the plurality of switching elements are formed so as to intersect with each other. Is provided. Further, as shown in FIG. 3, a color filter 6 and a counter electrode 7 are formed on the other substrate 5 (hereinafter also referred to as “counter substrate”). The display substrate 10 and the counter substrate 5 are arranged so that the pixel electrode and the counter electrode 7 face each other.

  In the present embodiment, a transmissive liquid crystal display device in which the pixel electrode has light transmittance will be described. However, the present invention is not limited to this, and for example, a reflective electrode in which the pixel electrode has light reflectivity is described. The present invention can also be applied to a liquid crystal display device and a transflective liquid crystal display device having light transmission and light reflection.

  As shown in FIG. 2, the periphery of the display substrate is scanned as a driving integrated circuit (hereinafter referred to as “driving IC”) for driving the pixel portion of the display unit 1. A signal line driving IC chip 2 and a data signal line driving IC chip 3 are mounted. In the liquid crystal display device of this embodiment, the display unit 1, the scanning signal line driving IC chip 2 and the data signal line driving IC chip 3 are directly mounted on one display substrate 10, that is, driving A COG (Chip On Glass) system in which an IC chip is mounted directly on a liquid crystal display device is employed. Further, in the present embodiment, the IC chips 2 and 3 are bonded to the display substrate 10 by an anisotropic conductive paste 40 (hereinafter referred to as “ACF”) (see FIGS. 3 and 4). ).

  In the illustrated example, the number of data signal line driving IC chips 3 is two. However, the number is not limited to this, and the number of data signal line driving IC chips 3 is appropriately determined based on the number of data signal lines and the number of outputs of the driving IC. In the illustrated example, the data signal line driving IC chip 3 and the scanning signal line driving IC chip 2 are separate and mounted on different sides of the display panel. The driving IC can be mounted on one side, and the data signal line driving IC chip and the scanning signal line driving IC chip can be mounted on one side.

  In addition, output wirings 21 and 31 and input wirings 22 and 32 are formed on the display substrate 10, and the output wirings 21 and 31 and the input wirings 22 and 32 are respectively connected to the output side of the IC chips 2 and 3 and to the input side. It is connected to the bump electrode 50 on the side. The output wirings 21 and 31 are connected to the scanning signal line or the data signal line.

  Further, as shown in FIG. 4, the driving IC chip 3 has a groove 60, and is divided into a first part 3 a and a second part 3 b that are electrically separated by the groove 60. In the present embodiment, the groove 60 is formed along the short direction of the driving IC chip. Further, as shown in FIG. 5, the display substrate 10 is formed with connection wiring 33 for electrically connecting the first part 3a and the second part 3b. The number of grooves 60 in the driving IC chips 2 and 3 is adjusted according to the size of the driving IC, and a plurality of grooves 60 are formed to form a plurality of first portions 3a and second portions 3b. What is divided is also within the intended scope of the present invention. In the above embodiment, the groove 60 is formed in the short direction. However, the groove 60 may be formed along the longitudinal direction, and it is also intended to form grooves that intersect each other. Within range. In the above description, only the data signal line driving IC chip 3 side has been described. However, the same configuration is sufficient for the scanning signal line driving IC chip 2 side.

  Next, a manufacturing flow of the driving IC chip of this embodiment will be described with reference to FIGS.

  First, the circuit element 71 is formed on the semiconductor wafer 70. Here, a plurality of IC chip circuits 71 are formed on a single wafer 70. Then, bump electrodes 50 are formed on the surface of the semiconductor wafer.

  Thereafter, the semiconductor wafer 70 is divided into IC chips by a dicing apparatus. In this division, it is possible to adopt a method of cutting the cutting line at one time. However, in this embodiment, a step cutting method of cutting one cutting line twice is adopted. In this step cut method, two rotary blades having different widths are used to cut twice. In addition, in this embodiment, although the cutting | disconnection by this step cut system is based, it is not limited to this.

  In addition, a groove 60 that is divided into a first part 3a and a second part 3b is also formed during this division. That is, in the step cut method, as shown in FIG. 8, two types of rotary blades having different widths are used, and in the first step, the groove 70 is formed in a state where the wafer 70 is not cut by the thick rotary blade 81, and thereafter In the second step, it is completely cut by the thin rotary blade 82. This is to prevent chipping of the driving IC chip. And in this embodiment, when forming a groove | channel by the rotary blade 81 of a thick width in the above-mentioned first step, the groove | channel 60 divided into the said 1st site | part 3a and the 2nd site | part 3b is formed.

  Next, a method for manufacturing a liquid crystal display device using the IC chip manufactured as described above will be described.

  First, the method for manufacturing a liquid crystal display device according to the present embodiment includes a procedure for performing surface processing on a pair of substrates, and a procedure for mounting the IC chip on the substrate subjected to the surface processing.

  First, in the surface processing procedure, a color filter, a counter electrode, a TFT, a scanning signal line, a data signal line, and the like are formed on a pair of substrates as in the conventional case. Note that the output wiring, input wiring, and connection wiring described above are formed on one substrate (display substrate) on which the IC chip is mounted. Note that these output wiring, input wiring, and connection wiring can be formed in the same process.

  In the procedure of mounting the IC chip on the substrate, the IC chip is mounted after the first portion 3a and the second portion 3b of the IC chip are positioned so as to be connected via the connection wiring of the substrate. To do. In this embodiment, the IC chip is bonded to the substrate by ACF.

  In addition, although the said embodiment consists of the said structure, this invention is not limited to the said structure, A design change is possible suitably within the range which this invention intends.

1 is a schematic perspective view of an embodiment of a display panel according to the present invention. It is a schematic plan view which shows the whole structure of the display panel of the embodiment. It is XX sectional drawing in FIG. It is YY sectional drawing in FIG. FIG. 3 is a schematic explanatory diagram for illustrating a wiring configuration of the display panel of the same embodiment. It is a schematic explanatory drawing which shows the relationship between the wafer and the circuit of a drive IC chip in the manufacturing method of the embodiment, (b) is an enlarged view of the main part of (a). It is explanatory drawing for demonstrating the dicing method of the IC chip for a drive in the manufacturing method of the embodiment, (A) is a procedure which forms a groove | channel in a first step, (B) is a description of the procedure cut | disconnected in a second step. FIG. A driving IC chip in a conventional display panel is shown.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Display part 2 IC chip for scanning signal line drive 3 IC chip for data signal line drive 3a 1st site | part 3b 2nd site | part 5 Opposite substrate 8 Liquid crystal layer 9 Sealing material 10 Display substrate 31 Output wiring 32 Input wiring 33 Inter-circuit connection wiring 40 ACF
50 Bump electrode 60 Groove 70 Semiconductor wafer 71 Circuit element 81/82 Rotary blade

Claims (8)

A display panel on which a driving IC chip having a circuit for driving a display unit is mounted on a panel substrate,
A groove is formed on the circuit surface of the driving IC chip, and the circuit is divided into a first part and a second part where the circuit is electrically divided by the groove,
The display panel according to claim 1, wherein connection wiring for electrically connecting the first part and the second part is formed on the panel substrate. The display panel according to claim 1,
The groove of the driving IC chip is formed at the time of one step cutting of the step cut type dicing apparatus. An IC chip provided to be mounted on another substrate and having a circuit formed thereon,
A groove is formed on the surface of the circuit, and the circuit is divided into a first part and a second part where the circuit is electrically separated by the groove, and the first part and the second part are the other parts. An IC chip which is provided so as to be electrically connected by connection wiring of the substrate when mounted on the substrate. An IC chip according to claim 3, wherein
The IC chip is characterized in that the groove is formed at the time of one step cutting of a step cut type dicing apparatus. A method of manufacturing a display panel by mounting a driving IC chip having a circuit for driving a display unit on a panel substrate,
Forming a groove on the circuit surface of the driving IC chip so that the circuit is electrically divided and divided into a first part and a second part;
A method for manufacturing a display panel, comprising mounting a driving IC chip on a panel substrate so that the first portion and the second portion are electrically connected by connection wiring formed on the panel substrate. A manufacturing method of a display panel according to claim 5,
A method of manufacturing a display panel, wherein the groove of the driving IC chip is formed at the time of one-step cutting of the step-cut type dicing apparatus. A method of manufacturing an IC chip provided to be mounted on another substrate and having a circuit formed thereon,
A step of forming the circuit and a step of forming a groove on the surface of the circuit;
The groove is formed so that the circuit is divided into a first part and a second part where the circuit is electrically divided, and the circuit is mounted on another substrate with the first part and the second part. A method of manufacturing an IC chip, wherein the IC chip is formed so as to be electrically connected by connection wiring of the substrate. An IC chip manufacturing method according to claim 7,
An IC chip manufacturing method, wherein the groove is formed at the time of one step cutting of a step cut type dicing apparatus.

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