JP2015169903A - display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a display device, in which a short circuit between adjoining wiring lines can be prevented in a connected part of a COF (chip on film) and a display panel.SOLUTION: The display device includes: a COF 30 including a flexible printed board 31, an IC disposed on the flexible printed board 31, a wiring line 33b disposed on the flexible printed board 31, with one end connected to the IC 32 and the other end extending to an end of the flexible printed board 31, a solder resist 34 covering an upper face at one end of the wiring line 33b, a solder resist 35 covering an upper face at the other end of the wiring line 33b, and a recess 39 disposed between the solder resist 34 and the solder resist 35, where an upper face of the wiring line 33b is exposed; a liquid crystal panel 20; and an ACF (anisotropic conductive film) 80 disposed to be accommodated in the recess 39 and containing conductive particles for connecting the COF 30 and the liquid crystal panel 20.

Description

  The present invention relates to a display device, and more particularly to a display device in which a COF and a display panel are connected by a thermosetting resin.

  A display device such as a liquid crystal display includes, for example, a liquid crystal panel that displays an image, a control circuit that performs display control on the liquid crystal panel, and a COF that drives the display panel based on a signal from the control circuit. ing.

  More specifically, the COF is an integrated circuit (IC) that generates a signal for driving a display panel using a signal from a control circuit on a flexible printed circuit (FPC), and In this structure, wirings for connecting the IC and the liquid crystal panel are formed.

  The COF is created, for example, by cutting individual COFs from a COF tape in which a plurality of COFs are arranged in a line on a long flexible film (for example, Patent Document 1). reference).

  In the COF tape, a plurality of COF regions in which each of the plurality of COFs is formed and an external region other than the COF region are set. The COF area is a rectangular area. In the COF region, an IC and a wiring are formed, respectively. A terminal connected to the control circuit is provided on one long side of the COF region, and a terminal connected to the liquid crystal panel is provided on the other long side. The wiring has one end connected to the IC and the other end connected to a test terminal provided in the external region. In addition, a solder resist for protecting the upper surface of the wiring is provided in the central portion of the COF. At the end of the COF, no solder resist is provided on the upper surface of the wiring, and the wiring is exposed. The area where the wiring is exposed becomes a terminal area connected to the display panel.

  Here, when the COF tape is cut and the COF is cut out, the wiring on the liquid crystal panel side is also cut together with the film, so the terminal on the liquid crystal panel side may be peeled off from the flexible printed circuit board, or the wiring may be short-circuited. is there. When terminal peeling or a short circuit between wirings occurs, there is a problem that the yield decreases. FIG. 11 is a diagram illustrating an example of terminal peeling.

  The terminal peeling or the short circuit between the wirings is likely to occur particularly when the wiring pitch of the COF is narrow and the distance between the wirings is short. In recent years, display devices such as liquid crystal displays have been improved in definition, and the wiring pitch on the output side (liquid crystal panel side) of the COF tends to be reduced, and the above-described problems have become more prominent.

  On the other hand, the COF tape which formed the soldering resist which protects the center part of COF also on the cutting line is disclosed (refer patent document 2). In addition, a solder resist is formed between the solder resist (an example of the first protective film) formed in the central portion of the COF and the solder resist (an example of the second protective film) formed on the cutting line. However, a terminal region (concave portion) in which the upper surface of the wiring is exposed is disposed.

JP 2010-232267 A JP 2011-114332 A

  By the way, COF is generally connected to the liquid crystal panel using ACF (Anisotropic Conductive Film) which is a thermosetting resin containing conductive particles.

  It is known that the volume of ACF expands by about 20 to 30% during thermocompression bonding. For this reason, when the second protective film is provided, there is a possibility that the ACF is blocked by the second protective film and becomes a lump. When ACF is agglomerated, there is a problem that the density of conductive particles increases, and adjacent wirings may be short-circuited.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a display device capable of preventing a short circuit between adjacent wirings at a connection portion between a COF and a display panel.

  In order to achieve the above object, a display device according to one embodiment of the present invention includes a flexible printed circuit board, an integrated circuit provided on the flexible printed circuit board, and wiring provided on the flexible printed circuit board. The wiring having one end connected to the integrated circuit and the other end extending to the end of the flexible printed circuit board; a first protective film covering the upper surface of one end of the wiring; and the upper surface of the end of the flexible printed circuit board And a second protective film covering the upper surface of the other end of the wiring, and a concave portion disposed between the first protective film and the second protective film, wherein the upper surface of the wiring is exposed. And a display panel, and a thermosetting resin disposed so as to be accommodated in the recess, and including conductive particles for connecting the COF and the display panel. And a fat.

  As described above, it is known that the ACF connecting the COF and the display panel expands by about 20 to 30% by thermocompression bonding. The display device having the above configuration performs, for example, thermocompression bonding in a state in which a thermosetting resin is disposed at the center of the recess so that the ACF fits in the recess. That is, in the display device having the above configuration, the thermosetting resin (ACF) is not blocked by the second protective film and is not agglomerated, so that it is possible to prevent adjacent wirings from being short-circuited.

  For example, the thermosetting resin may be disposed in the center of the first protective film and the second protective film, and the thermosetting resin may be the first protective film and the thermosetting resin. And the distance between the second protective film and the thermosetting resin may be the same.

  In the display device having the above configuration, the ACF is disposed at the center between the first protective film and the second protective film, or the distance between the first protective film and the thermosetting resin is the second protective film and the thermosetting resin. Since the thermosetting resin (ACF) is not blocked by the second protective film and is not agglomerated, it is possible to prevent adjacent wiring from being short-circuited. become.

  Further, the shape of the end portion of the second protective film on the concave portion side may be formed in a mountain shape in plan view.

  In the COF having the above configuration, since the end portion of the second protective film on the terminal region side is formed in a mountain shape, it is possible to suppress an increase in the density of the conductive particles in the thermosetting resin. Become. Therefore, the COF having the above configuration can reduce short-circuiting between wirings.

  Further, the shape of the end portion on the concave portion side of the second protective film may be formed in a wave shape in a plan view.

  In the COF having the above configuration, since the shape of the end portion of the second protective film on the terminal region side is formed in a wave shape, it is possible to suppress an increase in the density of the conductive particles in the thermosetting resin. Become. Therefore, the COF having the above configuration can reduce short-circuiting between wirings.

  The flexible printed board may have a cut in a region corresponding to the terminal region on the bottom surface.

  Since the COF having the above configuration has a cut in the bottom surface (the back surface of the terminal area), the resist is lifted from the surface of the display panel when the thermosetting resin is pressure-bonded to the display panel. It is possible to prevent damming. Thereby, the COF having the above-described configuration can prevent the density of the conductive particles in the thermosetting resin from increasing, and can reduce the short circuit between the wirings.

  In addition, the second protective film may be provided with a protruding portion that protrudes toward the display panel side, and the display panel has a side that contacts the second protective film on the second protective film side. A protruding portion may be provided.

  Since the COF having the above configuration has a convex portion protruding on the upper surface side of the second protective film, a gap is formed between the display panel and the COF when crimping to the display panel using a thermosetting resin. Is done. As a result, even if the thermosetting resin is thermally expanded, the thermosetting resin can escape into the gap, so that the formation of the thermosetting resin can be reduced. Thereby, the COF having the above-described configuration can prevent the density of the conductive particles from increasing, and can reduce the short circuit between the wirings.

  Further, even when the convex portion is provided on the display panel side, a gap is formed between the display panel and the COF so that the thermosetting resin is agglomerated as in the case where the convex portion is provided on the second protective film. Can be reduced.

  The protective film may be a solder resist.

  Since the COF having the above configuration uses a solder resist having an anchor effect as a protective film, it is possible to reduce the occurrence of terminal peeling and short circuit between adjacent wirings. In addition, since the solder resist is formed in a region other than the end portion of the wiring for other purposes in the COF, only by adding a solder resist forming region, substantially without adding a manufacturing process, A protective film can be formed.

  According to the present invention, it is possible to prevent a short circuit between adjacent wirings in the connection portion between the COF and the display panel.

It is sectional drawing which shows an example of the cross section of an open cell. It is an enlarged view of the broken-line part of FIG. 1A. It is a top view which shows an example of a structure of COF in embodiment. It is a side view which shows an example of a structure of COF in embodiment. It is a figure which shows an example of the COF tape in which the some COF in this Embodiment was comprised. It is an enlarged view of the broken-line part of FIG. 3A. It is a figure which shows an example of a structure of the display module in the modification 1. It is a figure which shows an example of a structure of COF in the modification 2. It is a figure which shows an example of the state of ACF in the modification 3. It is a figure which shows an example of the state of ACF in the modification 2. It is a figure which shows an example of the state of ACF in a comparative example. It is sectional drawing which shows an example of a structure of COF in the modification 4. FIG. 10 is a plan view showing an example of the configuration of a COF in Modification 5. FIG. 10 is a cross-sectional view showing an example of the configuration of a COF in Modification 5. It is a figure which shows an example of the state of terminal peeling and a short circuit.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In addition, each figure does not necessarily show exactly each dimension or each dimension ratio.

  Each of the embodiments described below shows a preferred specific example of the present invention. The numerical values, shapes, materials, constituent elements, arrangement positions and connecting forms of the constituent elements, steps, order of steps, and the like shown in the following embodiments are merely examples and are not intended to limit the present invention. The invention is specified by the claims. Therefore, among the constituent elements in the following embodiments, constituent elements that are not described in the independent claims are not necessarily required to achieve the object of the present invention, but are described as constituting more preferable embodiments. Is done.

(Embodiment)
A display device according to an embodiment will be described with reference to FIGS. 1A to 3B.

  In this embodiment, a case where the display device is a liquid crystal display will be described as an example.

[1. LCD display]
First, the configuration of the liquid crystal display will be described. In the following description, the X axis is set in the horizontal direction of the liquid crystal display, the Y axis is set in the vertical direction, and the Z axis is set in the depth direction (the front direction of the liquid crystal display is a positive direction).

  The liquid crystal display has a configuration in which the front cabinet, bezel, open cell, cell guide, optical sheet, reflection sheet, rear frame, control circuit, and power circuit are provided inside the front cabinet and rear cabinet that make up the housing. ing.

  A rear frame having a backlight and a reflective sheet disposed therein is disposed on the front surface of the rear cabinet. An optical sheet and a liquid crystal panel are disposed on the front surface of the rear frame. The outer peripheral edge of the liquid crystal panel is covered with a bezel and a cell guide.

  The bezel is a metal member that covers the outer peripheral edge of the liquid crystal panel constituting the open cell from the front. An open cell is an example of a liquid crystal module, and a detailed configuration will be described later. The cell guide is a synthetic resin member that covers the outer peripheral edge of the liquid crystal panel from the back surface. The optical sheet is composed of a plurality of members such as a diffusion plate. The reflection sheet is a member that reflects the light of the backlight provided on the rear frame.

  In the present embodiment, the control circuit is a circuit that performs display control of a liquid crystal panel, which will be described later, and is provided inside the rear cabinet. In the present embodiment, the power supply circuit is a circuit that generates power used in the control circuit and the liquid crystal panel from an external power supply, and is provided inside the rear cabinet.

[1-1. Configuration of LCD module (open cell)]
FIG. 1A is a cross-sectional view illustrating an example of a cross section of an open cell. FIG. 1B is an enlarged view of a broken line part of FIG. 1A.

  The open cell is an example of a liquid crystal module, and includes a liquid crystal panel 20, a COF 30, and a PCB (Printed Circuit Board, printed circuit board) 50.

  As shown in FIGS. 1A and 1B, the PCB 50 is disposed on the back side of the liquid crystal panel 20. The liquid crystal panel 20 and the PCB 50 are connected by a COF 30. The COF 30 is arranged so as to cover the side surfaces of the liquid crystal panel 20 and the PCB 50 in a curved state. The COF 30 has one end connected to the front surface of the liquid crystal panel 20 and the other end connected to the back surface of the PCB 50.

  As shown in FIG. 1B, the liquid crystal panel 20 and the COF 30 are connected by an ACF 80 which is an example of a thermosetting resin containing conductive particles.

[1-1-1. Configuration of LCD panel]
The liquid crystal panel 20 is an example of a display panel on which an image is displayed. As shown in FIG. 1B, a first polarizing plate (not shown), a color filter substrate 21, a liquid crystal layer (not shown), and an array substrate 24. And a second polarizing plate (not shown) or the like.

  On the array substrate 24, as shown in FIGS. 2 and 1B, a circuit (not shown) including TFTs and the like constituting the display pixel P, a source signal line SL (signal wiring 23 in FIG. 1B), a gate signal line GL etc. are formed. As shown in FIG. 1B, the signal line 23 extends from the display pixel P to the end of the liquid crystal panel 20.

  An insulating film 22 is formed on the signal wiring 23. The insulating film 22 is a thin film having a thickness of several mm. In the insulating film 22, for example, an opening is provided in a region for connecting the COF 30 and the signal wiring 23 at the end of the liquid crystal panel 20. In the opening portion, the signal wiring 23 is exposed (see the broken line portion in FIG. 1B). A plurality of wirings 33b (see FIG. 2B) of the COF 30 to be described later are connected to this portion using the ACF 80.

[1-1-2. Configuration of COF]
The COF 30 is composed of a rectangular flexible printed board on which an IC (integrated circuit) and wiring are mounted.

  2A and 2B are diagrams illustrating an example of the configuration of the COF 30. FIG. 2A and 2B, the X1 axis is set in the horizontal direction (right direction in the drawing) of the COF 30, the Z1 axis is set in the vertical direction (downward is positive), and the Y1 axis is set in the thickness direction. FIG. 2A is a plan view of the COF 30 as viewed from the side where the IC 32 is installed (hereinafter referred to as the upper surface side). FIG. 2B is a side view of the COF 30 as viewed from the negative direction of the Z1 axis.

  2A and 2B, the COF 30 has a structure in which an IC 32, a wiring 33, and solder resists 34 and 35 are formed on a flexible printed circuit board 31.

  The flexible printed circuit board 31 is configured using an insulating film having a thickness of several tens of μm to several hundreds of μm.

  In the present embodiment, the IC 32 is a source driver that generates a data signal having a voltage corresponding to a signal from the control circuit 70 input via the PCB 50 and applies the data signal to the source signal line. The luminance value of the display pixel P is determined according to the voltage value of the data signal. The IC 32 is disposed near the center of the flexible printed circuit board 31.

  The wiring 33 includes a plurality of wirings 33a and a plurality of wirings 33b.

  The plurality of wirings 33 a are wirings that connect the IC 32 and the PCB 50. The plurality of wirings 33 a are provided so that one end is connected to the IC 32 and the other end extends to the upper end of the flexible printed board 31. The wiring pitch of the plurality of wirings 33a is, for example, 50 μm. In the present embodiment, the plurality of wirings 33a have a relatively large wiring pitch and a low frequency of occurrence of problems such as terminal peeling. Therefore, the solder resist 35 is placed on the end of the wiring 33a on the PCB 50 side. Is not provided. The upper surface of the wiring 33a is exposed, and the upper surface is connected to the PCB 50.

  The plurality of wirings 33 b are wirings that connect the liquid crystal panel 20 and the IC 32. The plurality of wirings 33 b are provided so that one end is connected to the IC 32 and the other end extends to the lower end of the flexible printed board 31. As shown in FIG. 2B, the cut surfaces of the plurality of wirings 33b and the cut surfaces of the flexible printed circuit board 31 are exposed. This is because the COF tape was cut after the solder resist 35 was formed. The wiring pitch of the plurality of wirings 33b is, for example, 30 μm.

  Solder resist 34 or 35 is formed on the upper surfaces of the plurality of wirings 33b except for the terminal region 36 for connecting the plurality of wirings 33b and the liquid crystal panel 20. The terminal region 36 is a region where a plurality of wirings 33 b are exposed to the outside, and is provided between the solder resist 34 and the solder resist 35. The terminal region 36 and the exposed portion of the signal wiring 23 of the liquid crystal panel 20 are bonded using ACF. In other words, each of the plurality of wirings 33b of the COF 30 and each of the signal wirings 23 (source signal lines SL) of the liquid crystal panel 20 are connected by the ACF.

  The solder resists 34 and 35 are an example of a protective film for protecting the upper surface of the COF 30, and are made of an insulating material having a thickness of 10 μm to 20 μm.

  The solder resist 34 is an example of a first protective film that covers one end side of the plurality of wirings 33b from the upper surface. The solder resist 34 is formed so as to cover the IC 32 side with respect to the terminal region 36 in the upper surface of the wiring 33b.

  The solder resist 35 is an example of a second protective film that covers the other end side of the plurality of wirings 33b from the upper surface, and is a resist that protects end portions of the plurality of wirings 33b. The solder resist 35 is formed in a region outside the terminal region 36.

  Further, the solder resist 35 does not cover the cut surface of the COF 30 as shown in FIG. 2B. The cut surfaces of the plurality of wirings 33 b and the cut surface of the flexible printed circuit board 31 are exposed on the side surfaces of the COF 30. As will be described later, this is because the COF 30 is cut out from the COF tape 300 (see FIG. 3A) after the solder resist 35 is formed.

  Since the COF 30 of the present embodiment is provided with the solder resist 35, it is possible to reduce the occurrence of terminal peeling and short-circuiting between wirings during manufacturing.

  Since no protective film is formed between the solder resist 34 and the solder resist 35, a concave portion 39 is formed as a result. The height of the recess 39 is the height (thickness) of the solder resist 34 and the solder resist 35, and is, for example, 10 μm to 20 μm as described above. On the bottom surface of the recess 39, the top surfaces of the plurality of wirings 33b are exposed. That is, the bottom surface of the recess 39 is the terminal region 36.

  In the present embodiment, the case where the COF 30 is a source driver has been described as an example, but it may be a gate driver. In this case, the IC 32 generates a scanning signal and applies it to the gate signal line. Depending on the scanning signal, selection and non-selection of the display pixel P are switched.

[1-1-3. Configuration of PCB]
The PCB 50 is a rectangular plate-like printed circuit board that transmits a control signal output from the control circuit to the IC 32 of the COF 30.

  The PCB 50 is not an essential configuration. You may comprise so that a control circuit and COF30 may be directly connected by wiring.

[2. COF Manufacturing Method (Configuration of COF Tape)]
In the manufacture of the COF 30, a COF tape 300 in which a plurality of COFs 30 are arranged in a row is produced. Specifically, the step of mounting the wiring 33 and the IC 32 on the long film 310 and the step of further forming the solder resists 34 and 35 on the wiring 33 and the IC 32 are performed, whereby the COF tape 300 is performed. Is created.

  FIG. 3A is a diagram illustrating an example of a COF tape 300 on which components constituting a plurality of COFs 30 are mounted. FIG. 3B is an enlarged view of a broken line portion A1 in FIG. 3A.

  As shown in FIG. 3A, the long film 310 is provided with a COF region 30i (i = 1, 2, 3,...) And an external region other than the COF region 30i. In FIG. 3A, a region surrounded by a one-dot chain line is a COF region 30i corresponding to each COF 30. The alternate long and short dash line is the boundary between the external region other than the COF region 30i and the COF region 30i. In each of the COF regions 30i, an IC 32 and wirings 33a and 33b constituting the COF 30 are mounted. A test terminal is provided in an external region between two adjacent COF regions 30i. The test terminal is connected to the wiring 33b outside the COF region 30i.

  The long film 310 has flexibility, and a plurality of sprocket holes 311 arranged in a row are formed along each of the long sides. The long film 310 becomes the flexible printed circuit board 31 after cutting. The COF region 30i is set in a region where the central portion of the long film 310 and the sprocket hole 311 are not formed.

  In each of the regions surrounded by the alternate long and short dash line, an IC 32, which is a component constituting the IC, a plurality of wirings 33a and 33b, and solder resists 34 and 35 are formed.

  In this embodiment, the solder resist 35 is formed in a rectangular region. The solder resist 35 is arranged so that the alternate long and short dash line indicating the cut portion is located at the center portion. In addition, the solder resist 35 is not formed on the terminal regions 36 of the plurality of wirings 33 b and the liquid crystal panel 20 and the test terminals 37.

  In the present embodiment, since the solder resist 35 is formed not only inside the region surrounded by the alternate long and short dash line but also outside the region surrounded by the alternate long and short dash line, the terminals of the plurality of wirings 33b are peeled off at the time of cutting, etc. Can be reduced.

  The length of the long side of the solder resist 35 is set to be the same as the long side of the terminal region 36 of the COF 30 or longer than the long side of the terminal region 36. Further, it is desirable that the width of the solder resist 35 between the alternate long and short dash line and the long side of the solder resist 35 is set to a certain size so that terminal peeling or the like does not occur at the time of cutting.

  The test terminal 37 is a terminal used for confirming the operation of the COF 30 before cutting out each COF 30 from the COF tape 300. As shown in FIG. 3B, the test terminal 37 is provided corresponding to each COF 30 and connected to a plurality of wirings 33b of the corresponding COF 30.

  After the COF tape 300 is created, the COF 30 is cut out from the COF tape 300 (S20). The COF tape 300 is cut at a chain line portion. The plurality of wirings 33 b are cut together with the solder resist 35 and the long film 310. Since the COF tape 300 is cut after the solder resist 35 is formed, the cut surfaces of the plurality of wirings 33b are exposed to the outside. In other words, the solder resist 35 is not formed on the cut surface of the COF 30.

[3. Connection configuration of COF 30 and liquid crystal panel 20 (arrangement of ACF)]
In general, it is known that ACF 80 expands by about 20 to 30% during thermocompression bonding under normal thermocompression bonding conditions. In addition, as described above, since ACF 80 is a resin containing conductive particles having a diameter of 3 μm to 4 μm, the density of the conductive particles increases when adjacent to a lump, and adjacent wirings may be short-circuited. There is.

  Here, the COF described in Patent Document 2 can prevent terminal peeling at the time of cutting by the solder resist 35, but the solder resist 35 may block the ACF 80. When the ACF 80 is dammed up by the solder resist 35, it becomes a lump, and adjacent wirings may be short-circuited.

  Therefore, the liquid crystal display according to the present embodiment sets the position of the ACF 80 before thermocompression bonding so that the solder resist 35 does not dam the ACF80 expanded during thermocompression bonding. Has been.

  Specifically, for example, the position of the ACF 80 is set so that a gap for releasing the expanded ACF 80 is formed between the ACF 80 and the solder resist 35 before thermocompression bonding. As described above, since the ACF 80 expands by about 20 to 30%, the width of the gap may be set to about 20% of the length of the ACF 80 in the X-axis direction.

  At the time of thermocompression bonding, the expanded portion of the ACF 80 flows into the gap, and as a result, the ACF 80 is accommodated in the recess 39. Thereby, it is possible to prevent the ACF 80 from being stored in the recess 39 and being blocked by the solder resist 35 and becoming a lump. Thereby, it becomes possible to prevent that the density of electroconductive particle rises and adjacent wiring is short-circuited.

[4. Effect etc.]
The liquid crystal display according to the present embodiment is heated in a state in which a gap of about 20% of the ACF 80 is provided between the ACF 80 and the solder resist 35 so that the ACF 80 is not blocked by the solder resist 35. Crimp. Thereby, even if ACF80 expand | swells by thermocompression bonding, an expansion | swelling part can flow in a clearance gap. As a result, it is possible to prevent the ACF 80 from becoming a lump, and it is possible to prevent adjacent wirings from being short-circuited.

(Modification 1)
In the above embodiment, as shown in FIG. 1B, the case where the ACF 80 after thermocompression bonding is in contact with the solder resist 35 has been described as an example, but the present invention is not limited to this.

  FIG. 4 is a cross-sectional view showing an example of the configuration of the display module in the present modification, and shows the state of the display module after thermocompression bonding. As shown in FIG. 4, the position of the ACF 80 before thermocompression bonding may be set so that a gap is formed between the solder resist 35 and the ACF 80.

  The ACF 80 may be arranged at the center of the recess 39 after thermocompression bonding. In other words, the position of the ACF 80 before the thermocompression bonding may be set so that the distance between the solder resist 35 and the ACF 80 after the thermocompression bonding is the same as the distance between the solder resist 34 and the ACF 80.

  If comprised in this way, it can avoid that ACF80 is dammed.

(Modification 2)
The second modification is different from the first embodiment and the first modification in the shape of the solder resist 35 of the COF 30.

  FIG. 5 is a diagram illustrating an example of the configuration of the COF 30 in the present modification.

  As shown in FIG. 5, the solder resist 35 in this modification has a long side on the terminal region 36 side formed in a mountain shape in plan view.

  FIG. 7 is a diagram illustrating an example of the state of the ACF 80 in the present modification. FIG. 8 is a diagram illustrating an example of the state of the ACF 80 in the comparative example.

  As shown in FIGS. 7 and 8, when the long side of the solder resist 35 on the terminal region 36 side is formed in a mountain shape, the long side of the solder resist 35 is formed in a linear shape. , The length of the long side becomes long. In the case of FIG. 7, the distance in which the conductive particles are arranged becomes long, and a gap is easily formed between the particles. If there is a gap between the particles, it will not conduct, so it is possible to reduce the short circuit between adjacent wires. That is, by forming the long side of the solder resist 35 on the side of the terminal region 36 in a mountain shape, the density of conductive particles can be reduced even when the ACF 80 is agglomerated, and the short circuit between the wirings can be reduced. Is possible.

(Modification 3)
The modified example 3 is different from the above embodiment and modified examples 1 and 2 in the shape of the solder resist 35 of the COF 30.

  FIG. 6 is a diagram illustrating an example of the configuration of the COF 30 in the present modification.

  As shown in FIG. 6, the solder resist 35 in the present modification has a long side on the terminal region 36 side formed in a wave shape in plan view.

  Even when the long side of the solder resist 35 on the terminal region 36 side is formed in a wave shape, the length of the long side becomes long as in the case where the long side is formed in a mountain shape as in Modification 1. Thereby, even when ACF80 becomes a lump, it is possible to reduce the density of conductive particles and to reduce the short circuit between the wirings.

(Modification 4)
The modified example 4 is different from the above embodiment and the modified examples 1 to 3 in the configuration of the COF 30.

  FIG. 9 is a cross-sectional view showing an example of the configuration of the COF 30 in the present modification. In the COF 30 shown in FIG. 9, a cut 38 is formed on the back surface of the flexible printed board 31 and the back surface of the terminal region 36.

  The notch 38 allows the solder resist 35 to be lifted from the liquid crystal panel 20 when the COF 30 is thermocompression bonded to the liquid crystal panel 20. Thus, a gap is formed between the solder resist 35 and the liquid crystal panel 20 when the COF 30 is thermocompression bonded to the liquid crystal panel 20. Since there is a gap between the solder resist 35 and the liquid crystal panel 20, even when the ACF 80 is thermally expanded, it is possible to prevent the ACF 80 from being dammed and to prevent adjacent wirings from being short-circuited. Can do.

(Modification 5)
Modification 5 differs from the above embodiment and Modifications 1 to 4 in the configuration of the solder resist 35.

  FIG. 10A is a plan view showing an example of the configuration of the COF 30 in the present modification. FIG. 10B is a cross-sectional view showing an example of the configuration of the COF 30 in the present modification.

  As shown in FIGS. 10A and 10B, the solder resist 35 of this modification is provided with a convex portion 35a.

  By providing the convex portion 35a, it is possible to form a gap in which the ACF 80 can escape between the COF 30 and the liquid crystal panel 20 when the ACF 80 is expanded by thermocompression bonding. As a result, the ACF 80 can be prevented from being dammed, and adjacent wirings can be prevented from being short-circuited.

  The convex portion 35a may be provided on the liquid crystal panel 20. The shape of the convex portion 35a may be any shape such as a hemispherical shape, a columnar shape, or a truncated cone. Moreover, the number of the convex parts 35a is arbitrary.

(Other embodiments)
Although the display device according to the embodiment of the present invention has been described above, the present invention is not limited to this embodiment.

  (1) For example, the liquid crystal module (an example of a display module) of the above embodiment uses the COF of this embodiment for both the COF 30 connected to the source signal line and the COF connected to the gate signal line GL. However, it is not limited to this. For example, when the wiring pitch is smaller than 50 μm, that is, when a problem such as terminal peeling is likely to occur, the COF of this embodiment is applied, and in other cases, the conventional COF is used. It doesn't matter.

  (2) In the COF of the above embodiment, the solder resist 35 is provided on the upper surface of the end of the wiring 33b that connects the liquid crystal panel 20 and the IC 32, but the upper surface of the end of the wiring 33a that connects the PCB 50 and the IC 32. In addition, a solder resist may be provided.

  (3) Furthermore, the above embodiment and the above modification examples may be combined.

  The present invention can be applied to a display device using COF, such as a liquid crystal display and an organic EL display.

20 Liquid crystal panel 21 Color filter substrate 22 Insulating film 23 Signal wiring 24 Array substrate 30 COF
30i COF region 31 Flexible printed circuit board 32 IC
33, 33a, 33b Wiring 34, 35 Solder resist 36 Terminal area 37 Test terminal 38 Notch 39 Recess 50 PCB
70 Control circuit 80 ACF
300 COF tape 310 Film 311 Sprocket hole

Claims (9)

A flexible printed circuit board, an integrated circuit provided on the flexible printed circuit board, and a wiring provided on the flexible printed circuit board, wherein one end is connected to the integrated circuit and the other end is an end of the flexible printed circuit board. A first protective film covering the upper surface of one end side of the wiring, a second protective film covering the upper surface of the end portion of the flexible printed circuit board and the upper surface of the other end side of the wiring, A COF (Chip on Film) provided with a recess disposed between one protective film and the second protective film, the upper surface of the wiring being exposed;
A display panel;
A thermosetting resin disposed so as to be accommodated in the recess, the thermosetting resin including conductive particles for connecting the COF and the display panel;
Display device. The thermosetting resin is disposed in the center of the first protective film and the second protective film,
The display device according to claim 1. The thermosetting resin is disposed at a position where an interval between the first protective film and the thermosetting resin and an interval between the second protective film and the thermosetting resin are the same.
The display device according to claim 1. The shape of the end portion on the concave portion side of the second protective film is formed in a mountain shape in plan view,
The display device according to claim 1. The shape of the end portion on the concave portion side of the second protective film is formed in a wave shape in plan view,
The display device according to claim 1. The flexible printed circuit board has a notch formed in a region corresponding to the terminal region on the bottom surface.
The display device according to claim 1. The second protective film is provided with a protruding portion that protrudes toward the display panel.
The display device according to claim 1. The display panel is provided with a protrusion protruding toward the second protective film at a position in contact with the second protective film.
The display device according to claim 1. The protective film is a solder resist,
The display device according to claim 1.