JP2010098145A - Device for thermocompression bonding between electrode terminal and flexible wiring board, and method of manufacturing flat display panel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To eliminates breaks and cracks of a glass substrate when press-bonding a TCP to an end part of the glass substrate in a PDP manufacturing device, and to simplify the device. <P>SOLUTION: A plurality of air cylinders 41 are arranged under points 42 of a panel receiving jig 40 so as to support them at stroke ends, and the pressure of each air cylinder is set and managed through an electro-pneumatic regulator 43 by a control part 46. A total thrust force nFs of air cylinders 41 on holding a PDP 7 is controlled so as to be equal to or greater than a weight Fg of the PDP 7 and to be equal to or smaller than the sum of a pressure force Fh of a press-bonding head 5 and the weight of the PDP 7 (Fg<nFs<Fg+Fh), whereby the entire glass substrate is lowered in response to pushing-in operation of the press-bonding head on press-bonding to reduce a force applied to the glass substrate, and thus breaks and cracks of the glass substrate can be eliminated on press-bonding the TCP. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention is an improved electrode terminal thermocompression bonding for thermocompression bonding of an FPC (flexible circuit board) to an electrode terminal of a flat display panel such as a PDP (plasma display panel) or LCD (liquid crystal display panel). The present invention relates to a device and a new connection method using the device.

  As a display screen of a flat display device (FPD), a display panel such as a plasma display panel or a liquid crystal panel is known. These display panels are formed by laminating two transparent plates such as glass (hereinafter referred to as glass substrates), and a flexible circuit board (so-called FPC) is provided in an electrode terminal row led to an edge of at least one of the glass substrates. A flexible printed circuit (Flexible Printed Circuit) is thermocompression bonded through an anisotropic conductive adhesive film (ACF), thereby connecting the panel and the drive circuit.

  By the way, when the FPC is thermocompression bonded to the glass substrate, there is no problem if the pressing force of the pressure-bonding head acts purely as a force for pressing the ACF with the opposing backup. The force for pushing the pressure-bonding head against the portion and the weight of the pressure-bonding head are applied as stresses, and the force applied to the glass substrate is increased, resulting in a problem of fine partial cracks and cracks. In order to solve this problem, conventionally, as described in “Patent Document 1”, a structure in which a receiving point of a panel substrate is supported by a spring-loaded holding pin for absorbing stress, an opposing crimping head, and a backup (hereinafter referred to as a pressure mechanism). Measures have been taken to reduce the stress applied to the glass substrate with a structure in which the glass substrate is rotatably supported.

Japanese Patent Laid-Open No. 9-214132

  However, such a conventional electrode terminal thermocompression bonding apparatus requires a high degree of skill and time for adjusting the spring pressure of the holding pin, and according to the latter configuration, it can be used as a backup against deformation and warping of the substrate. While the parallelism of the pressure bonding head can be followed well, there is a drawback that the stress applied to the substrate during pressure bonding is not sufficiently absorbed, and the apparatus configuration is complicated and the equipment cost is expensive.

  Accordingly, it is an object of the present invention to provide an electrode terminal thermocompression bonding apparatus and a thermocompression bonding method that do not damage a glass substrate when a flexible circuit board is thermocompression bonded to an electrode terminal array of a display panel.

  In view of the above problems, the present invention proposes a configuration in which the display panel to which the FPC is connected is held in a floating state, thereby moving the movement of the glass substrate in conjunction with the up-and-down movement of the crimping head. As the glass substrate follows, the pressure-bonding surface and the pressure-bonding head are always kept parallel, and the heating of the pressure-bonding head and the pressure force on the glass substrate are made uniform.

  As a specific technical means for holding the display panel in a float state, the present invention is characterized by a configuration in which n receiving points that distribute and support the display panel are mounted on each stroke end of an air cylinder that can be controlled in common. To do. When the thrust of the air cylinder is Fs, the electropneumatic regulator connected to the air cylinder is controlled so that the total thrust nFs has a relationship of Fg <nFs <Fg + Fh with respect to the weight Fg of the display panel and the pressure Fh of the crimping head. As a result, the display panel held on the receiving point moves up and down in conjunction with the pressure applied by the pressure head, and can absorb unnecessary stress.

  According to the present invention, it is possible to suppress breakage of the glass substrate at the time of thermocompression bonding of the FPC to the electrode terminals of the display panel, and it is possible to improve the productivity of a display using a display panel such as a plasma display panel. Moreover, according to the apparatus of this invention, since the mechanism of an apparatus can be simplified, equipment cost can be reduced.

  The contents of the present invention will be described in detail below using examples.

An embodiment of the present invention will be described with reference to FIGS. 1 to 6 by taking a plasma display panel (hereinafter referred to as PDP) as an example.
FIG. 4 is an exploded perspective view showing an example of the structure of a general PDP. The PDP 7 is roughly composed of a front substrate 1 and a back substrate 2. A plurality of pairs of surface discharge X electrodes 8 and Y electrodes 9 constituting a display line are arranged in parallel on a glass substrate which is a base material of the front substrate 1. This electrode group is covered with a dielectric layer 10, and its surface is further covered with a protective layer 11 such as MgO. Similar to the front substrate 1, an address electrode 12 is arranged in a direction substantially orthogonal to the X electrode 8 and the Y electrode 9 on the glass substrate of the rear substrate 2 made of glass, and is further covered by the dielectric layer 10. Yes. Partitions 13 are arranged on both sides of the address electrode 12 to partition cells in the column direction. Further, a phosphor 14 that is excited by ultraviolet rays and generates visible light is applied to the side surfaces of the dielectric layer 10 and the partition wall 13 on the address electrode 12. The front substrate 1 and the rear substrate 2 are overlapped so that the protective layer 11 and the partition wall 13 are in contact with each other. The substrate periphery of the front substrate 1 and the back substrate 2 is sealed with a sealing member 4, and a discharge gas is injected therein to form a PDP 7.
In addition, a structure in which all three electrodes, that is, an X and Y electrode pair and an address electrode, are arranged on a glass substrate on one side is also known in the PDP. It leads to the edge part of a glass substrate.

  FIG. 5 is a plan view showing the structure of a general PDP module on which a drive circuit is mounted. The chassis 15 provided on the back surface of the back substrate 2 of the PDP 7 has an X drive circuit 16 for applying a voltage to the X electrode 8, a Y drive circuit 17 for applying a voltage to the Y electrode 9 functioning as a scanning electrode, and upper and lower surfaces of the back substrate. The upper and lower address drive circuits 18 apply voltages to the address electrodes 12 derived by dividing each of the address electrodes 12, a power supply circuit 19 of each drive circuit, and a control circuit 20 that controls them.

  Here, for example, in the case of a panel having a horizontal resolution of 1280, there are 3840 (1280 × 3) address electrodes 12, each of which is formed into a group of 192 and led out alternately above and below the back substrate to form a terminal group. It has become a thing. Therefore, an FPC is prepared for each electrode terminal group, and one end of the FPC is attached to the electrode terminal group via an ACF (anisotropic conductive adhesive film) (not shown), and they are integrally heated and pressurized. The connection is fixed.

  Then, a multi-terminal connector provided in advance at the other end of each FPC is coupled to a receptacle 21 provided in the address drive circuit 18 on the back surface, thereby enabling conduction to each address electrode 12. The connection from the X electrode 8 and the Y electrode 9 of the front substrate 1 to the X drive circuit 16 and the Y drive circuit 17 is performed in the same manner as described above.

  The FPC used for connecting the electrode terminal array and the drive circuit is not only a flexible circuit board or a flexible printed cable, but also a TCP (Tape Carrier Package) in the form of an electronic component in which a driver IC is directly mounted on the board or cable. ).

  FIG. 6 is a side view of the PDP module. The discharge space between the front substrate 1 and the rear substrate 2 is sealed with a sealing member 4. Further, a chassis 15 is attached to the back surface of the back substrate 2 by an adhesive material 22. As described above, the FPC 3 whose one end is thermocompression bonded to the electrode terminal group of the back substrate 2 is connected to the address drive circuit 18 by coupling the connector on the other end and the receptacle 21. The X drive circuit 16 and the Y drive circuit 17 are also connected to the display electrodes XY of the front substrate 1 by corresponding FPCs (not shown).

  FIG. 1 is a side view showing a state where an electrode terminal of a back substrate 2 and a terminal portion of an FPC 3 are being crimped using a thermocompression bonding apparatus according to an embodiment of the present invention. This thermocompression bonding apparatus includes a receiving point 42 for holding the PDP 7 on top, a panel receiving jig 40 comprising a mechanism 50 for positioning at four corners of the PDP 7 and a jig frame 48 for supporting the mechanism 50, and a receiving point 42. An air-air cylinder 41 that holds the lower part, an electro-pneumatic regulator 43 that adjusts the pressure of the air cylinder 41, a control unit 46 that controls the electro-pneumatic regulator 43 to set and manage the pressure of the air cylinder 41, and can be driven vertically The pressure bonding mechanism 45 includes a thermocompression bonding head 5 having a pressure bonding surface having a width corresponding to the width of the electrode terminal row to be grouped and a backup 44. The pressurizing mechanism 45 is held on a rail (not shown) so as to be movable in the arrangement direction of the electrode terminal rows, and moves the crimping position by the arrangement pitch dimension of the electrode terminal group.

  First, the flow up to the pressure setting of the air-air cylinder that holds the PDP 7 in the float state will be described with reference to FIG. With the electrode terminal group of the back substrate 2 of the PDP 7 as a reference, temporary connection is performed for each sheet while keeping the terminal portions of the FPC 3 aligned. As shown in FIGS. 1 and 2, the PDP 7 is placed on a plurality (n) of receiving points 42 that are evenly distributed on the panel receiving jig 40. The receiving point 42 is made of, for example, hard resin, and the lower surface thereof is held by a free end portion of a sliding rod 41a that is moved by the air pressure of the air air cylinder 41, that is, a stroke end 41b.

  FIG. 2 is a plan view showing a state in which the PDP 7 is placed on the panel receiving jig 40. In FIG. 2, a PDP 7 composed of a front substrate 1 and a rear substrate 2 is placed on a panel receiving jig. In the PDP 7, the rear substrate 2 has a larger diameter in the vertical direction than the front substrate 1, and an address electrode terminal is formed in this portion. FIG. 2 shows a configuration in which the FPC 3 is connected to the terminal of the address electrode. In the PDP, the front substrate has a large diameter in the horizontal direction, and terminals of the X electrode 8 and the Y electrode 9 are formed at the left and right ends of the front substrate in the horizontal direction.

  In FIG. 2, the positioning of the PDP 7 in the horizontal direction is performed by the glass substrate positioning mechanism 50. The glass substrate positioning mechanism 50 is attached to a jig frame 48, and the glass substrate positioning mechanism 50 and the jig frame 48 constitute a panel receiving jig 40.

  In FIG. 2, the PDP 7 is supported by six stroke ends 41 b that are in contact with the back substrate 2. The stroke end 41 b is a tip portion of the sliding rod 41 a extending from the air cylinder 41.

  A heating head 5 for connecting the address electrode terminals and the FPC 3 by thermocompression bonding at the end of the back substrate 2 in FIG. 2 is described. In FIG. 2, the heating head connects one FPC 3 to the rear substrate, but when the connection of one FPC 3 is completed, the heating head moves to the left side of FIG. 2 to connect the next FPC 3. .

  Returning to FIG. 1, the pressure of the air air cylinder 41 holding the PDP 7 is set prior to the thermocompression bonding operation. The pressures of the n air-air cylinders 41 for each receiving point are set in common by the control unit 46 and are electrically adjusted via the electropneumatic regulator 43. At that time, the total thrust nFs of the air-air cylinder holding the PDP 7 is equal to or greater than the weight Fg of the PDP 7 and is equal to or less than the sum of the pressure Fh applied by the pressure-bonding head 5 and the weight Fg of the PDP 7 during pressure bonding (Fg <nFs <Fg + Fh). Set as follows. With this setting, the PDP 7 is placed on the receiving point 42 so as to float lightly. Since the optimum pressure setting value can be stored in the control unit 46 as data for each type of PDP, the second and subsequent pressure setting operations can be omitted.

  Next, the crimping process will be described. After the pressure mechanism 45 having the pressure bonding head 5 and the backup 44 is moved to the pressure bonding position, the stage 60 on which the panel receiving jig 40 is placed is lowered to a predetermined position by an unillustrated lifting mechanism. At this time, it is confirmed that there is a gap between the lower surface of the PDP 7 and the backup 44, that is, d in FIG. 1 is about 1/1000 to 1/3000 of the length L in the long side direction of the PDP 7.

  In FIG. 1, since the backup is fixed, there is a risk of damaging the PDP 7 if there is no predetermined distance between the back substrate 2 of the PDP 7 and the backup. On the other hand, according to the present invention, even when the distance d in FIG. 1 is the above value, the PDP 7 can move up and down with the pressure of the heating head 5 when thermocompression bonding is performed by the heating head 5. The back substrate 2 is not damaged by stress during the crimping.

  On the other hand, if the distance d in FIG. 1 is too large, the amount of movement of the PDP 7 during thermocompression bonding becomes too large, and stress may be applied to the PDP 7, specifically, the back substrate 2. Therefore, d in FIG. 1 is preferably suppressed to about 1.5 mm at the maximum.

  Next, the pressure bonding head 5 is lowered from above, and pressure bonding is performed so as to sandwich the PDP 7 with the backup 44. The terminal row is divided into a plurality of groups as described above, and one electrode terminal group is crimped by one crimping. When the pressure head 5 is brought into contact with the surface of the FPC stacked on the electrode terminal group and pressurization is started, the substrate is pushed down until the lower surface of the back substrate 2 follows the backup 44 as shown in FIG. The pressure bonding of the FPC is performed in a state where the pressure bonding surfaces of the head 5 and the back substrate 2 are parallel.

  FIG. 3 is a diagram in which the heating head 5 is lowered to connect the electrode terminal of the back substrate 2 and the FPC 3. The electrode terminal of the back substrate 2 and the FPC 3 are connected via an ASC (Anisotropic Conductive Fim) (not shown). Since the other structure of the thermocompression bonding apparatus of FIG. 3 is the same as that of FIG. 1, description is abbreviate | omitted.

  In FIG. 3, if the pressure force of the crimping head is received only at the end of the back substrate 2, the problem of cracks as described above occurs. However, according to the present invention, the entire lightly floating PDP 7 is subjected to pressure from the pressure-bonding head and sinks down, and is pressed without being affected by the weight or pressure of the pressure-bonding head. The stress applied to the pressure-bonding surface of the substrate 2 is reduced, and the generation of cracks and chips can be prevented.

  As described in FIG. 1, the PDP 7 is supported by, for example, six stroke ends 41b. For each stroke end 41 b, the pressure of the air air cylinder 41 is set in common by the control unit 46 and is electrically adjusted via the electropneumatic regulator 43. When the thrust of each air cylinder 41 is Fs, the thrust by the six air cylinders is 6 Fs, which is larger than the weight Fg of the PDP.

  In this state, the pressure head descends and pushes the back substrate of the PDP 7. At this time, the back substrate 2 is supported by the backup 44, but since there is a gap d between the back substrate 2 and the backup 44, the back substrate 2 is stressed by this amount. This stress is Fh. In the present invention, when the weight Fg of the PDP 7, the thrust of the air cylinder 41 is Fs, and the pressure applied due to the pressure of the pressure head is Fh, the relationship is (Fg <6Fs <Fg + Fh).

  Here, conventionally, the stress Fh is applied to a specific portion of the back substrate 2 and causes damage to the back substrate. However, in the present invention, since the stress is distributed over the entire back substrate 2 by the plurality of air cylinders 41, damage to the back substrate can be prevented.

  The shapes and number of PDPs, TCPs, panel receiving jigs, and air cylinders shown in FIGS. 1 to 3 are merely examples, and are not limited to those shown in FIGS. 1 and 2. For example, in FIGS. 1 to 3, the number of stroke ends 41 b that support the PDP 7 is six. However, this number n may be determined in consideration of the size of the panel, the thrust of the air cylinder, and the like. However, n is desirably 4 or more.

  In the above description, the connection between the terminal of the address electrode formed on the back substrate 2 of the PDP 7 and the FPC 3 is taken as an example. When the FPC 3 is connected to the terminals of the X electrode 8 and the Y electrode 9 formed on the front substrate of the PDP 7, the same operation can be performed by turning the PDP 7 upside down.

  In the first embodiment, the case of connecting the PPC 3 to the PDP 7 has been described as an example. The present invention can be applied not only to the PDP 7 but also to the connection of the FPC 3 to a liquid crystal display device, for example.

  FIG. 7 is a perspective view of the liquid crystal display panel. In FIG. 7, a liquid crystal display panel is formed by overlapping a color filter substrate 102 on which a color filter is formed on a TFT substrate 101 on which pixels including thin film transistors (TFTs) and pixel electrodes are arranged in a matrix. A liquid crystal layer is sandwiched between the TFT substrate 101 and the color filter substrate 102. Since the transmission amount of the light L from the backlight passing through the liquid crystal layer is controlled for each pixel, an image is formed.

  Since the liquid crystal only transmits polarized light, a lower polarizing plate 104 (not shown) is attached to the back side of the TFT substrate 101 to convert light from the backlight into linearly polarized light. The linearly polarized light is modulated by the liquid crystal layer, and the modulated light passes through the color filter substrate 102 and is again polarized by the upper polarizing plate 103, and an image is visually recognized by human eyes.

  In FIG. 7, the TFT substrate 101 is formed larger than the color filter substrate 102, and a terminal portion 105 is formed at the end of the TFT substrate 101 at a portion larger than the color filter substrate 102. 7 is a terminal portion 105 for a scanning line, and in the vertical direction, the terminal portion 105 is a terminal portion 105 for a video signal line.

  As shown in FIG. 7, in the liquid crystal display device, unlike the PDP 7, the terminal portion 105 is formed only on the TFT substrate 101. Therefore, the FPC 3 may be connected only to the terminal portion 105 formed on the TFT substrate 101. Also in the liquid crystal display device, as with the PDP 3, the connection of the FPC 3 is performed by thermocompression bonding the FPC 3 to the TFT substrate 101 via the ASC.

  FIG. 8 is a side view showing a state in which the FPC 3 is connected to the liquid crystal display panel of FIG. In the case of the liquid crystal display device, as shown in FIG. 8, the liquid crystal display panel on which the upper polarizing plate 103 and the lower polarizing plate 104 are attached is placed on the panel receiving jig in the thermocompression bonding device of FIG. The lower polarizing plate 104 in FIG. 8 is placed on the stroke end that is the tip of the sliding rod 41 a from the air cylinder 41. In this state, since the protective film is still attached to the lower polarizing plate 104, the lower polarizing plate 104 is not damaged.

  The subsequent connection process is the same as that described in the first embodiment. In the liquid crystal display device, the thickness of the glass substrate used is about 0.5 mm, and the stress on the glass substrate during thermocompression bonding is large. Yield can be improved.

It is a schematic diagram of the thermocompression bonding apparatus of the present invention. It is another schematic diagram of the thermocompression bonding apparatus of the present invention. It is a top view of the thermocompression bonding apparatus of this invention. It is a disassembled perspective view which shows the structure of the display area of the module of PDP. It is a rear view which shows the structure of the module of PDP. It is a side view which shows the structure of the module of PDP. It is a perspective view of a liquid crystal display device. It is a side view of a liquid crystal display device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Front substrate 2 ... Back substrate 3 ... FPC (flexible circuit board)
4 ... Sealing member 5 ... Heating head 7 ... PDP
8 ... X electrode 9 ... Y electrode 10 ... dielectric layer 11 ... protective layer 12 ... address electrode 13 ... partition wall 14 ... phosphor layer 15 ... chassis 16 ... X drive circuit,
17 ... Y drive circuit,
18 ... Address drive circuit,
DESCRIPTION OF SYMBOLS 19 ... Power supply circuit 20 ... Control circuit 21 ... Connector receptacle 22 ... Adhesive material 40 ... Panel receiving jig 41 ... Air air cylinder 42 ... Receiving point 43 ... Electro-pneumatic regulator 44 ... Backup 45 ... Pressurizing mechanism 46 ... Control part 48 ... Jig frame 50 ... glass substrate positioning mechanism 101 ... TFT substrate 102 ... color filter substrate 103 ... upper polarizing plate 104 ... lower polarizing plate 105 ... terminal portion.

Claims (6)

A thermocompression bonding apparatus for thermocompression bonding a flexible circuit board to an electrode terminal led to an end face of a substrate constituting a display panel,
The lower surface of the display panel is supported by a plurality of receiving points that can move up and down,
The plurality of receiving points are arranged at the ends of strokes of a corresponding plurality of air cylinders, and the plurality of air cylinders are controlled by a control unit,
A thermocompression bonding apparatus, wherein a crimping head and a backup are arranged so as to sandwich a portion where the electrode terminals are formed on the substrate of the display panel. A thermocompression bonding apparatus for connecting an electronic component to an electrode terminal formed on at least one glass substrate of a plasma display panel comprising a pair of glass substrates,
A plurality of points for supporting the lower surface of the glass substrate, a panel receiving jig having a mechanism for positioning at the four corners of the glass substrate, and a stage that can be moved up and down by setting the panel receiving jig,
Each of the plurality of points supporting the glass substrate is constituted by a stroke end of a sliding rod extending from a corresponding plurality of air cylinders,
The pressures of the plurality of air cylinders are controlled by an electropneumatic regulator and a controller that controls the electropneumatic regulator,
A crimping head for crimping the electronic component to the electrode terminal of the glass substrate on which the electrode terminal is formed, driving means for moving the crimping head up and down, and a lower part of the crimping head arranged in parallel to the electrode terminal. A thermocompression bonding apparatus for plasma display panel electrode terminals, comprising a backup for receiving the glass substrate from below when the electronic component is crimped. A plasma display panel manufacturing method comprising a pair of glass substrates facing each other, and connecting a flexible wiring substrate by thermocompression bonding corresponding to the electrode terminal of the plasma display in which an electrode terminal is led to an end of at least one of the glass substrates There,
The lower surface of the glass substrate on which the electrode terminals are formed is supported by a plurality of receiving points that can move up and down,
Each of the plurality of receiving points is disposed at a tip of each stroke of the plurality of air cylinders, and the plurality of air cylinders are commonly controlled by a control unit,
In the glass substrate on which the electrode terminal is formed, the flexible wiring substrate and the electrode terminal formed on the glass substrate are thermocompression bonded so that the portion on which the electrode terminal is formed is sandwiched between a crimping head and a backup. A method of manufacturing a plasma display panel characterized by the above. The weight of the plasma display panel is Fg, and the stress that the glass substrate receives by the crimping head is Fh.
When the plurality is n and the total thrust of the n air cylinders is nFs,
4. The method of manufacturing a plasma display panel according to claim 3, wherein the pressure of the air cylinder is set by the controller so that (Fg <nFs <Fg + Fh). The backup is fixed and the crimping head is movable;
Before crimping the glass substrate on which the electrode terminal is formed by the crimping head and the flexible wiring substrate, the interval between the backup and the glass substrate is set to L in the long side direction of the glass substrate. 4. The method of manufacturing a plasma display panel according to claim 3, wherein a gap of L / 1000 to L / 3000 is provided. A TFT substrate in which pixels including pixel electrodes and TFTs are formed in a matrix, a color filter substrate on which a color filter is formed, and a liquid crystal layer is sandwiched between the TFT substrate and the color filter substrate, and the TFT An electrode terminal is formed at an end of the substrate, and a flexible wiring substrate is thermocompression-bonded to the electrode terminal.
The lower surface of the TFT substrate on which the electrode terminals are formed is supported by a plurality of receiving points that can move up and down,
Each of the plurality of receiving points is disposed at a tip of each stroke of the plurality of air cylinders, and the plurality of air cylinders are commonly controlled by a control unit,
In the TFT substrate on which the electrode terminal is formed, the flexible wiring substrate and the electrode terminal formed on the TFT substrate are thermocompression bonded so that the portion on which the electrode terminal is formed is sandwiched between a crimping head and a backup. A method for manufacturing a liquid crystal display device.

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