JP2009224394A - Jointing apparatus and jointing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a jointing apparatus and a jointing method capable of improving productivity. <P>SOLUTION: The jointing apparatus 100 is provided with a laser beam irradiation section for irradiating an ACF 10 with a laser beam for heating the ACF 10. The laser beam irradiation section is provided with: a plurality of laser sources 32; optical fibers 33, 41 for transmitting the laser beams emitted from the laser sources 32 so that the laser beams can propagate in a direction traveling toward the ACF 10; and a plurality of fixtures 45, having a plurality of lenses 42 for converting the laser beams emitted from the optical fibers into parallel lights. The intensities of the laser beams, respectively emitted from the plurality of laser sources, are controlled so as to vary independently from each other, and be constant in time or variable in time. The surface of an object to be jointed is irradiated with the laser beams emitted from the plurality of laser sources at different positions, and thus the entire region defined by the contour of the object to be jointed is irradiated with the laser beam. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a connection between a display panel represented by a liquid crystal display panel and a drive circuit board, a connection between the display panel and an electronic component bonded thereto, a carrier such as a tape or a package to which the display panel is connected to the electronic component. The present invention relates to a joining device suitable for joining with a member and a joining method using the joining device.

  In recent years, liquid crystal display devices are rapidly spreading as image display devices for personal computers and other various monitors.

  In this type of liquid crystal display device, generally, a backlight which is a planar light source for illumination is disposed on the back surface of the liquid crystal display panel. The backlight illuminates the entire liquid crystal surface having a predetermined spread with uniform brightness, whereby the image formed on the liquid crystal surface is visualized. In many cases, the liquid crystal display device includes a liquid crystal display panel configured by enclosing a liquid crystal material between two glass substrates, a printed circuit board for driving the liquid crystal material mounted on the liquid crystal display panel, A backlight unit is provided on the back surface of the liquid crystal display panel via a liquid crystal display panel holding frame, and an outer frame frame covering the backlight unit.

  As one of liquid crystal display devices, there is a TFT (Thin Film Transistor) liquid crystal display device. In the case of a TFT liquid crystal display device, one of the two glass substrates constituting the liquid crystal display panel constitutes an array substrate, and the other constitutes a color filter substrate.

  The array substrate is a glass substrate on which a TFT, a display electrode, a signal line, a lead electrode for electrically connecting to a printed circuit board, and the like, which are driving elements of a liquid crystal material, are formed. Since the TFTs are regularly arranged on the surface of the glass substrate, this glass substrate is generally called an array substrate.

  On the other hand, the color filter substrate is a glass substrate having a color filter (typically a red filter, a green filter and a blue filter) formed on the surface thereof. In addition to the color filter, a common electrode, a black matrix, an alignment film, and the like are also formed on the surface of the color filter substrate (surface of the glass substrate).

  In many cases, a printed circuit board provided in a liquid crystal display device is connected to an extraction electrode formed on an array substrate via a TAB (Tape Automated Bonding) tape carrier (hereinafter also simply referred to as TAB). Alternatively, a printed circuit board is also mounted on a liquid crystal display panel by a TAB technique via a package (typically TCP (Tape Carrier Package)) in which an LSI chip is connected to a tape film.

  Moreover, COF (Chip on film / FPC) and SOF (System on Film) are mentioned as the packaging technology similar to the TAB technology.

  The TAB input lead conductors are connected to corresponding conductors on the printed circuit board. On the other hand, the output lead conductor of TAB is connected to the corresponding extraction electrode of the array substrate. When connecting the TAB lead conductor and the corresponding conductor of the printed circuit board, for example, a bonding material in which particles made of a conductive material are dispersed in solder or resin as an adhesive (typically ACF (Anisotropic Conductive Film) and ACP (Anisotropic Conductive Paste)) are used. An anisotropic conductive material that does not contain conductive particles is also used as a bonding material. A resin adhesive that does not contain conductive particles (for example, NCP (Non Conductive Particle / Paste)) is also used as a bonding material.

  Similarly, ACF, ACP, NCP, or the like is used when connecting the output lead conductor of the TAB to the corresponding extraction electrode of the array substrate. Further, ACF, ACP, NCP or the like is used not only for these connections but also for the connection between the LSI chip on the TCP and the film.

  In addition to the mounting technology using TAB, there is a mounting technology called COG (Chip On Glass). This COG is a technique for joining electronic components such as an IC (Integrated Circuit) chip (hereinafter also referred to as a silicon chip or a bare chip) mainly made of silicon with a material such as ACF, ACP, or NCP on an array substrate. Specifically, the bump electrode formed on the electronic component and the extraction electrode on the array substrate are electrically connected by a bonding material such as ACF.

  There are two types of ACF, a thermoplastic ACF using a thermoplastic resin as an adhesive and a thermosetting ACF using a thermosetting resin as an adhesive. The joining method using the thermoplastic ACF and the thermosetting ACF is the same in that heat pressurization accompanied by heating and pressurization is performed.

  The above-described electrode bonding is conventionally performed by the procedure described below. First, a liquid crystal panel substrate is carried in. Next, the mounting portion is cleaned and the ACF is attached to the substrate glass. Subsequently, provisional pressure bonding is performed at a low temperature with precise positioning of a bare chip, a film or the like (hereinafter also referred to as a mounting component). Subsequently, the ACF is cured at a high temperature, and the main pressure bonding is performed to connect the electrode of the panel substrate and the electrode of the mounting component. In addition, inspection and carrying-out work are performed after this crimping | compression-bonding.

  Of these steps, the most time-consuming is the main pressure bonding. Conventionally, in this process, the ACF is heated and pressurized by pressing a heater tool bar held at a high temperature against the mounted component. Conventionally, in this pressure bonding, for example, a heating and pressing time of about 10 seconds is required. However, the heating and pressing time depends on the material properties of ACF.

  The heating method using the heater tool can provide high reliability. However, this heating method requires two steps, a temporary crimping step and a final crimping step, and the crimping itself is performed by heating and curing the ACF through heat conduction from the heater tool bar to the joining component. It takes time to join and is a factor that determines the tact.

  In order to avoid this problem, there is a tact improvement method in which the ACF is heated by irradiating the ACF with laser light, thereby joining at a high speed and eliminating the provisional crimping step that has been necessary in the past, and joining only by this crimping. Proposed.

For example, Japanese Patent Laid-Open No. 2006-253665 (Patent Document 1) discloses a step of sandwiching ACF by applying pressure between a glass substrate and an electrode member, and causing the ACF to generate heat by absorbing laser light. A bonding method comprising the steps.
JP 2006-253665 A

  Japanese Patent Laid-Open No. 2006-253665 exemplifies a wobbling method and a painting method as methods for irradiating the ACF with laser light. According to the above document, the wobbling method is a method of drawing the irradiation locus of the laser beam so that the center of the irradiation spot advances while turning, and the filling method is a method of filling the irradiation region with a large number of parallel lines. is there.

  However, as a result of the inventors' diligent research, when joining electronic components having a plurality of electrodes, it is necessary to sequentially irradiate each electrode with laser light to cure the ACF in order to ensure mechanical and electrical reliability. It turned out to be undesirable. That is, in this crimping step, it is necessary to cure the heat-reactive adhesive contained in the ACF in a state where the conductive particles contained in the ACF are pressed between the electrode of the electronic component and the electrode of the panel substrate. If the ACF is locally cured by sequentially irradiating the pair of electrodes with the laser beam, it will be a hindrance when the already cured ACF sandwiches the other electrode pair. For the bonded electrode pair, the ACF may be cured in a state where the conductive particles are not sufficiently pressed.

  The present invention has been made to solve the above-described problems, and a bonding apparatus and a bonding method capable of improving productivity in bonding electrodes via an anisotropic conductive material The purpose is to provide.

  In summary, the present invention includes an extraction electrode composed of a plurality of first electrodes arranged on a glass substrate as an object to be bonded, a bonding object of the extraction electrode, and a plurality of first electrodes arranged in the arrangement. It is a joining device that electrically joins a plurality of second electrodes arranged in correspondence with each other with an adhesive made of a heat-reactive resin interposed therebetween. The bonding apparatus includes a laser beam irradiation unit that irradiates a laser beam for heating the thermally reactive resin toward the adhesive. The laser light irradiation unit includes a plurality of laser light sources, and a laser control unit that controls the intensity of the laser light emitted from each of the plurality of laser light sources to be constant or temporally change with respect to time. Including. The joining apparatus irradiates laser light emitted from each of the plurality of laser light sources to different positions on the surface of the joining object on which the plurality of second electrodes are formed, so that the contour of the joining object is obtained. The whole area of the determined area is irradiated with laser light.

  Preferably, the laser beam irradiation unit further includes a beam shaping unit for shaping the beam shape of the laser beam irradiated onto the adhesive by the plurality of laser light sources.

  Preferably, the bonding target includes a plurality of electrodes formed on the surface of the bonding target as a plurality of second electrodes. The region irradiated with laser light in the adhesive is substantially the same size as the surface of the object to be joined on which the plurality of electrodes are formed.

  Preferably, in the laser beam irradiation unit and the beam shaping unit, the power of the laser beam in the irradiation region that is a region irradiated with the laser beam in the adhesive is 90% of the power of the laser beam emitted from the laser beam irradiation unit. As described above, the laser beam is concentrated on the irradiation region.

  Preferably, the laser beam irradiation unit includes a plurality of optical fibers that transmit the laser beams and each of the laser beams emitted from the plurality of laser light sources travels in a direction toward the adhesive. And a plurality of lens holding members having a plurality of lenses for converting the laser light into parallel light. In each lens holding member, the plurality of lenses are arranged in one direction at a pitch determined so that parallel light overlaps.

  Preferably, the plurality of lens holding members include parallel light emitted from each of the plurality of lenses provided on one lens holding member and a plurality of lenses provided on another lens holding member different from the one lens holding member. The parallel light emitted from each of the light beams is arranged so as to gather in the beam shaping unit.

  Preferably, the bonding apparatus is formed of a transparent material and is disposed between the support member that supports the glass substrate, the plurality of lens holding members, and the support member, and the plurality of first electrodes on the glass substrate. When alignment is performed with a camera that photographs the plurality of first electrodes and the plurality of second electrodes via the support member and the glass substrate for alignment of the plurality of second electrodes of the joining object. The camera further includes a camera moving mechanism that moves the camera to a predetermined position and retracts the camera from a position on the optical path of the parallel light when parallel light is emitted from each of the plurality of lenses.

  Preferably, the bonding apparatus detects the temperature distribution of the irradiation region based on the temperature detection unit that detects the temperature of the plurality of locations in the irradiation region of the laser light in the adhesive and the temperature of the plurality of locations detected by the temperature detection unit. And a temperature distribution generation unit to be generated. The laser control unit controls each of the plurality of laser light sources based on the temperature distribution generated by the temperature distribution generation unit.

  Preferably, the bonding apparatus includes a support member that is formed of a transparent material and supports the glass substrate, and a beam shaping unit that shapes the beam shape of the laser light irradiated to the adhesive by the plurality of laser light sources. Further prepare. The beam shaping unit is disposed between the plurality of lens holding members and the support member, and includes a slit for shaping the beam shape in a first direction along the surface of the glass substrate. The support member has a slope that intersects the surface facing the glass substrate and is inclined with respect to the vertical direction of the facing surface.

  Preferably, the angle formed between the perpendicular to the slope and the parallel light is larger than the total reflection angle of the parallel light on the slope.

  Preferably, the bonding apparatus further includes an absorber that is provided along the inclined surface and that can absorb the laser beam.

Preferably, the slope is a rough surface.
Preferably, the bonding apparatus further includes an absorber that is provided in the vicinity of the support member and in the reflection direction of the laser light reflected on the inclined surface and can absorb the laser light.

  Preferably, of the surfaces of the support member, the surface from which the laser beam reflected on the slope is emitted from the inside of the support member is a rough surface.

  Preferably, the bonding apparatus further includes a moving mechanism that moves the plurality of lens holding members along a second direction perpendicular to the first direction.

  Preferably, the joining device further includes a pressurizing device for applying pressure to the joining object from the opposite side to the adhesive. The laser beam irradiating unit irradiates the adhesive with the laser beam in a state where pressure is applied to the objects to be joined by the pressurizer.

  Preferably, the pressure device includes a pressing member for pressing the object to be joined. At least one through hole is formed in the pressing member. The joining apparatus further includes a vacuum suction unit for vacuum-sucking the object to be joined to the pressing member via at least one through hole.

  Preferably, the pressurizing device includes a pressing portion for pressing the object to be joined. The material of the pressing member is a material selected from ceramic, quartz, and glass.

  Preferably, the laser light irradiation unit guides the laser light from the corresponding laser light source to make the intensity of the laser light uniform, and collective irradiation is possible so that planar irradiation with the uniformed laser light is possible. And a mask for shaping the beam shape of the laser light emitted from the plurality of light guides.

Preferably, the adhesive is an adhesive in which conductive particles are dispersed in a thermally reactive resin.
According to another aspect of the present invention, an extraction electrode composed of a plurality of first electrodes arranged on a glass substrate as an object to be bonded, a plurality of first electrodes included in a bonding object of the extraction electrode, and This is a joining method using a joining device that electrically joins a plurality of second electrodes arranged in correspondence with each other with an adhesive made of a heat-reactive resin interposed therebetween. The bonding method includes a step of pressurizing the bonding target, and a step of irradiating a laser beam for heating the heat-reactive resin toward the adhesive in a state where the bonding target is pressurized. The step of irradiating the laser beam includes a step of controlling the intensity of the laser beam emitted from each of the plurality of laser light sources so as to be constant or temporally change with respect to time, and the plurality of first electrodes. By irradiating laser light emitted from each of a plurality of laser light sources to different positions on the surface of the object to be welded, the entire region determined by the contour of the object to be welded is irradiated with the laser light. Steps.

  According to the present invention, a plurality of electrodes formed on a glass substrate and a plurality of electrodes to be bonded (typically TCP, bare chip, etc.) are bonded via an adhesive with a heat-reactive adhesive. In this case, it is possible to irradiate laser light with an intensity distribution to the area determined by the outline of the object to be joined, so that high-speed and reliable joining can be realized and productivity can be improved. Become.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals, and description thereof will not be repeated.

  FIG. 1 is a schematic block diagram of a liquid crystal display device that is a processing target of a bonding apparatus according to an embodiment of the present invention.

  Referring to FIG. 1, a liquid crystal display device includes a liquid crystal display panel (shown as “LCD” in the figure) 1, a TCP (Tape Carrier Package) 2, a printed circuit board 3, an interface unit 4, a flexible board ( 6) (shown as “FPC” in the figure).

  The TCP 2 is disposed between the liquid crystal display panel 1 and the printed circuit board 3. The TCP 2 includes a driver IC 5 for driving the constituent elements of the liquid crystal display panel.

  The printed circuit board 3 is a board on which a circuit for driving a liquid crystal material mounted on the liquid crystal display panel 1 is formed. The interface unit 4 includes wiring connected to a peripheral circuit disposed around the liquid crystal display panel 1. The flexible substrate 6 is for electrically connecting the printed circuit board 3 and the interface unit 4.

  The liquid crystal display panel 1 and the printed circuit board 3 are joined by TCP2. More specifically, the electrode (extraction electrode) of the liquid crystal display panel 1 and the electrode of the TCP 2 are electrically joined by ACF and have an integral shape. Similarly, the electrode of the TCP 2 and the electrode of the printed circuit board 3 are electrically joined by ACF and become an integral shape.

  A COG (Chip On Glass) method is also used for manufacturing a liquid crystal display panel. FIG. 1 shows not only the mounting of TCP 2 but also the mounting of driver IC 5 in a bare chip state (left side of liquid crystal display panel 1). Bump electrodes (not shown) are provided on the surface of the bare chip (driver IC 5). This bump electrode is electrically joined to the electrode (extraction electrode) of the liquid crystal display panel 1 by ACF.

  FIG. 1 shows a state in which both the TCP 2 and the bare chip are mounted on the liquid crystal display panel for convenience of explanation. Therefore, for example, the bare chip is not mounted on the liquid crystal display panel 1, and only the TCP may be mounted on the liquid crystal display panel 1. However, the bonding apparatus according to the present embodiment (see FIG. 4) can be used for both TCP2 mounting and bare chip mounting.

FIG. 2 is a diagram for explaining a configuration example of TCP 2 shown in FIG.
Referring to FIG. 2, TCP 2 includes a carrier tape 2a, a plurality of lead conductors 2b, and a driver IC 5. A plurality of lead conductors 2b are formed on the surface of the carrier tape 2a, and a driver IC 5 is mounted. Each of the plurality of lead conductors 2b is electrically connected to a bump electrode (not shown) formed on the surface of the driver IC 5.

FIG. 3 is a diagram for explaining the ACF.
FIG. 3A illustrates an example of the structure of the ACF. Referring to FIG. 3A, the ACF 10 has a configuration in which an infinite number of microparticles (conductive particles) 11 are contained in a binder that is an epoxy or acrylic adhesive. The binder is a thermally reactive resin. The binder may be a thermosetting resin or a thermoplastic resin.

  FIG. 3B is a diagram illustrating the state of the ACF 10 when heat and pressure are applied to the ACF 10. With reference to FIG. 3B, the ACF 10 is sandwiched between the electrodes 15 and 16. When heat and pressure are applied to the ACF 10, pressure is applied to portions of the entire ACF 10 that are in contact with the electrodes 15 and 16. FIG. 3B shows only the portion of the entire ACF 10 that is in contact with the electrodes 15 and 16.

  The microparticle 11 includes a resin core 13, a nickel (Ni) plating layer 12 formed on the surface of the resin core 13, and a gold plating layer 14 formed outside the nickel plating layer 12. When heat and pressure are applied to the ACF 10, the microparticles 11 dispersed inside the ACF 10 come into contact with each other, thereby bringing the plating layers into contact with each other. Furthermore, since the resin core 13 is an elastic body, a repulsive force is generated in the resin core 13. Due to this repulsive force, the plating layer physically contacts the electrode 16 and the electrode 15. As a result, a conductive path is formed between the electrode 15 and the electrode 16.

  FIG. 3C is a diagram showing an ACF having a two-layer structure as another example of the structure of the ACF. As shown in FIG. 3C, in the ACF having a two-layer structure, the binder and the microparticles are separately formed in separate regions, that is, the binder region 10a and the microparticle region 11a. In this configuration as well, a conductive path can be formed between electrodes sandwiching the ACF by heating and pressurization, as in the above-described configuration. In addition, by using ACF having a two-layer structure, it is possible to suppress a relative positional shift between the two electrodes due to heating and pressurization.

[Configuration of joining device]
FIG. 4 is a configuration diagram of joining apparatus 100 according to the embodiment of the present invention. In the following description, a case where the bonding apparatus 100 mainly bonds the driver IC 5 (bare chip) to the liquid crystal display panel 1 via the ACF 10 will be described. In the following description, the X, Y, and Z directions perpendicular to each other may be referred to as “left-right direction”, “front-rear direction”, and “up-down direction”, respectively.

  With reference to FIG. 4, the joining apparatus 100 includes a cylinder 20, a chip tray 21, a cylinder moving mechanism 22, and a pressure head 25.

  The driver IC 5 and the ACF 10 are inserted between the cylinder 20 (pressure head 25) and the liquid crystal display panel 1.

  The pressure head 25 is attached to the tip of the cylinder 20. When the cylinder 20 is lowered, the pressure head 25 comes into contact with the driver IC 5 (bare chip). The cylinder 20 controls the pressure applied to the driver IC 5 (and the ACF 10) by adjusting the height of the pressure head 25 when the driver IC 5 and the liquid crystal display panel 1 are joined.

  The cylinder moving mechanism 22 is for moving the cylinder 20 in the left-right direction (X direction). The configuration of the cylinder moving mechanism 22 is not particularly limited. For example, the cylinder moving mechanism 22 includes a ball screw and a linear motor.

  On the chip tray 21, driver ICs 5 (driver ICs 5 b) used for joining with the liquid crystal display panel 1 are arranged in advance. For example, the driver IC 5b is picked up from the chip tray 21 by a robot arm (not shown, the same applies hereinafter). The cylinder 20 is moved to the position of the chip tray 21 by the cylinder moving mechanism 22 and receives the driver IC 5b from the robot arm. As will be described later, a vacuum suction portion for vacuum-sucking the TCP 2 is provided inside the cylinder 20, and a vacuum suction hole is formed in the pressure head 25. As a result, the cylinder 20 vacuum chucks the driver IC 5b. Then, the cylinder 20 returns to the position of the liquid crystal display panel 1.

  Note that the robot arm described above may directly carry the driver IC 5b to the position of the liquid crystal display panel 1. Thus, the method and means for carrying the driver IC 5 (bare chip) from the chip tray 21 to the liquid crystal display panel 1 are not particularly limited.

  The bonding apparatus 100 further includes a laser device 31 that emits laser light for heating the driver IC 5 and the ACF 10. The laser device 31 includes a plurality of laser light sources 32 therein. The power of the laser light emitted from the laser light source 32 and the number of the laser light sources 32 are appropriately determined based on, for example, conditions required for heating and curing of the ACF 10.

  The bonding apparatus 100 further includes a plurality of optical fibers 33, a laser cooling device 34, a laser control unit 35, a power supply device 36, a fiber repeater 40, and a plurality of optical fibers 41. The plurality of optical fibers 33 are provided corresponding to the plurality of laser light sources 32, respectively. Each optical fiber 33 transmits the laser light emitted from the corresponding laser light source 32.

  The laser cooling device 34 realizes a function of keeping the temperature of the laser device 31 constant by cooling the laser device 31. As a result, the power of the laser beam output from the laser device 31 can be stabilized. The cooling method is not particularly limited, and may be air cooling with a fan or water cooling, for example.

  The laser control unit 35 controls the laser cooling device 34 and controls the outputs of the plurality of laser light sources 32. For example, if the temperature of the laser light source 32 is equal to or lower than a predetermined limit temperature, the laser control unit 35 continues to output laser light to the laser light source 32, and the temperature of the laser light source 32 exceeds the limit temperature. In that case, the output of the laser beam to the laser light source 32 is stopped.

  In the present embodiment, the laser light source 32 is a semiconductor laser. The power supply device 36 outputs laser light from the semiconductor laser by supplying current to the semiconductor laser. In addition, the power supply device 36 supplies a power supply voltage to other devices of the bonding apparatus 100.

  The fiber repeater 40 is provided to transmit light from the plurality of optical fibers 33 to the plurality of optical fibers 41. The number of optical fibers 33 and the number of optical fibers 41 may be the same or different. For example, by coupling light from each of the two optical fibers 33 to one optical fiber 41 by an optical coupler, the power of light propagating through the optical fiber 41 can be increased.

  Further, by providing the fiber repeater 40 in the middle of the optical transmission path (that is, the optical fiber) for transmitting the laser light, for example, when any of the plurality of optical fibers 33 needs to be replaced, the replacement work is performed. Can be easily. That is, the fiber repeater 40 can facilitate maintenance work of the bonding apparatus 100.

  The bonding apparatus 100 further includes a laser light protection cover 38, a plurality of lenses 42, a plurality of lens holders 43, and a fixture 45.

  The laser light protective cover 38 is provided to prevent the laser light from leaking around the bonding apparatus 100.

  The plurality of lenses 42 are provided corresponding to the plurality of optical fibers 41, respectively. Each of the plurality of lenses 42 is a collimating lens. Laser light output from one end of the optical fiber 41 corresponding to the lens by the lens 42 becomes parallel light.

  The plurality of lens holders 43 are provided corresponding to the plurality of lenses 42, respectively. Each lens holder 43 fixes one end of the corresponding lens 42 and the corresponding optical fiber 41. Thereby, it becomes possible to install the lens 42 and the optical fiber 41 according to a predetermined arrangement. The lens 42 and the optical fiber 41 are arranged so that parallel light is emitted.

  The fixture 45 is for fixing a predetermined number of unit (for example, eight) lens holders 43 in a line. Therefore, a plurality of lenses 42 provided in each fixture 45 (each lens 42 is fixed by a lens holder 43) emits a line of parallel light arranged in a line.

  The joining apparatus 100 further includes a support member 51 for supporting the plurality of fixtures 45, a slide rail 52 for moving the support member 51 in the front-rear direction (Y direction), and a slide rail 52, and The fixed portion 53 disposed outside the movable support member 51, the backup substrate 55 installed on the upper surface of the fixed portion 53, and the X-direction movable light-shielding member attached to the fixed portion 53 so as to be movable in the X direction. 56 and a Y-direction light shielding member 57 installed in contact with the backup substrate 55. The backup substrate 55 is fixed on the upper surface of the fixing portion 53 so as not to move.

  The joining apparatus 100 further includes a camera 60 and an arm 62 for moving the camera 60. The camera 60 photographs the extraction electrode and the bump electrode through the backup substrate 55 and the liquid crystal display panel 1 in a state where the extraction electrode of the liquid crystal display panel 1 (panel substrate) and the bump electrode of the corresponding driver IC face each other. To do. An image photographed by the camera 60 is used to align the bump electrode with respect to the extraction electrode.

  When laser light is emitted from the lens 42 for heating the ACF 10, the camera 60 is retracted from the position on the optical path of the laser light by the arm 62. Therefore, it is possible to prevent the laser beam from being blocked by the camera 60. The moving direction of the arm 62 is not specified, and may move along the X direction, for example, or may rotate within the XY plane.

  The joining apparatus 100 further includes a control device 70, a motor driver 75, and a display device 80. The control device 70 controls the entire joining device 100. The motor driver 75 drives a motor (linear motor in the above example) provided in the cylinder moving mechanism 22 and a motor (not shown) for moving the arm 62 in accordance with a command from the control device 70.

  The display device 80 displays various information such as an image taken by the camera 60, an instruction input by the user, a current operating state of the joining device 100, and the like. The display device 80 may also serve as an input device like a touch panel display. Alternatively, an input device such as a mouse or a keyboard may be connected to the joining device 100, and a result of the user operating the input device may be displayed on the display device 80.

  FIG. 5 is a first diagram for illustrating a configuration of a laser beam irradiation unit included in bonding apparatus 100 according to the present embodiment.

  FIG. 6 is a second diagram for illustrating a configuration of a laser beam irradiation unit included in bonding apparatus 100 according to the present embodiment.

  Referring to FIGS. 5 and 6, the laser light irradiation unit includes a plurality of laser light sources 32. In the present embodiment, a semiconductor laser is used for the laser light source 32 in consideration of energy efficiency and the size of the mounting region (that is, the laser light irradiation region in the ACF 10).

  In the present embodiment, the wavelength of the laser light is selected from the range of 600 nm to 1100 nm. As will be described in detail later, light having a wavelength in this range easily passes through the backup substrate 55, the liquid crystal display panel 1, and a resin (for example, epoxy resin) that is a main material of the ACF 10, and is a semiconductor mounted on the TCP 2. It is easily absorbed by single crystal silicon, which is the main material of the chip (or bare chip), and polyimide, which is the main material of the carrier tape of TCP2, and is hardly absorbed by aluminum, which is the main material of the wiring pattern. As a result, not only the ACF 10 but also the silicon chip (or carrier tape) is heated by the laser beam. Therefore, since the ACF 10 can be heated not only by the heat generation of the ACF 10 itself but also by heating with a silicon chip (or carrier tape), the laser beam can be effectively used for heating the ACF.

  Light from the laser light source 32 propagates through the optical fiber 33. The optical fiber 33 and the optical fiber 41 are optically coupled by the fiber repeater 40.

  The fiber repeater 40 includes an input connector 47 and an output connector 48 for connecting the optical fiber 33 and the optical fiber 41. The end of the optical fiber 33 is inserted into the input connector 47, and the end of the optical fiber 41 is inserted into the output connector 48. By connecting the input connector 47 and the output connector 48, the optical fiber 33 and the optical fiber 41 are optically coupled.

  The optical fibers 33 and 41 are for guiding the laser light so that the laser light emitted from the laser light source travels in the direction toward the ACF 10. The laser light emitted from the laser light source 32 propagates through the optical fibers 33 and 41 and is adjusted to a parallel light beam by the lens 42 fixed to the lens holder 43. The laser beams collimated by each of the plurality of lenses 42 provided in one fixture 45 become light beams that are parallel to each other and overlap each other.

  The fixture 45 is configured so that the inclination of the lens holder 43 can be adjusted. For example, as shown in FIG. 5, the inclination of the fixture 45 can be adjusted by rotating the fixture 45 around a rod-shaped rotation shaft 54 provided between the support member 51 and the fixture 45. The inclination of each fixture 45 is set so that the laser beam LB from the lens provided in each fixture 45 gathers at the ACF 10. A part of the laser beam LB emitted from the plurality of lenses 42 is blocked by the X-direction movable light blocking member 56.

  Note that the rotation shaft 54 and the like are shown in FIG. 5 as an example of a configuration for realizing the adjustment of the inclination of the fixture 45. Therefore, the configuration for adjusting the inclination of the fixture 45 is not limited to that shown in FIG.

  The temperature detector 64 is for measuring the temperature of the ACF 10. Here, the object itself radiates an electromagnetic wave having a wavelength corresponding to the temperature regardless of whether the object is heated. Therefore, the temperature of the object can be measured in a non-contact manner by detecting the electromagnetic wave radiated from the object. In the present embodiment, as the temperature detection unit 64, one that can detect the intensity or wavelength of electromagnetic waves radiated from an object can be used. For example, a thermopile, a heat ray camera, a photodiode, or the like can be used for the temperature detection unit 64, for example.

  The backup substrate 55 is for supporting the liquid crystal display panel 1. In the conventional heater tool method (method in which the ACF is pressed by a heated head), the backup substrate only needs to be made of a material having such a rigidity that hardly deforms when being pressed. Therefore, the conventional backup substrate may be an opaque object. However, in the present embodiment, the camera 60 (see FIG. 4) images the electrodes of the liquid crystal display panel and the driver IC 5 through the backup substrate 55, and the driver IC 5 is positioned based on the captured image. . Further, the backup substrate 55 must transmit laser light (laser beam LB). Further, when the driver IC 5 and the liquid crystal display panel 1 are joined via the ACF 10, the pressure is applied to the driver IC 5 by the pressure head 25 (see FIG. 4), so the backup substrate 55 must have rigidity. Therefore, the backup substrate 55 is made of a transparent material having high rigidity. As a material of the backup substrate 55 for satisfying such requirements, quartz glass is preferable.

  In addition, it is preferable that the antireflection coating is performed on the surface 55c (incident surface of the laser beam LB) of the backup substrate 55. Thereby, since the light quantity of the laser beam which permeate | transmits the backup board | substrate 55 can be increased, the power of the light irradiated to ACF10 can be raised. Therefore, it becomes possible to raise the temperature of ACF10 to the target temperature in a short time.

  However, there is a possibility that the wavelength of light transmitted through the backup substrate 55 coated with the anti-reflection coating is red-shifted with respect to the wavelength of light transmitted through the backup substrate 55 not coated with the anti-reflection coating. Therefore, when the antireflection coating is applied to the surface 55c of the backup substrate 55, it is preferable to use a camera 60 having a high resolution on the infrared side. As a result, even if the antireflection coating is applied to the surface of the backup substrate 55, the electrodes of the liquid crystal display panel 1 and the electrodes of the driver IC 5 can be photographed with a camera, so that the electrodes can be accurately aligned.

  The power supply device 36 controls a current value applied to the laser light source 32 (semiconductor laser) in accordance with a command from the laser control unit 35. Although not shown, the power supply device 36 is provided with a current control element for flowing a current according to a control signal, for example, represented by a transistor.

  The temperature detection unit 64 outputs a signal indicating the detected temperature of the ACF 10 to the temperature calculation unit 68 via the signal line 65 and the signal connectors 66 and 67. The temperature calculation unit 68 calculates the temperature of the ACF 10 based on the signal from the temperature detection unit 64. Then, the temperature calculation unit 68 outputs the calculation result, that is, information on the temperature of the ACF 10 to the temperature control unit 69.

  The temperature control unit 69 sends an instruction to the laser control unit 35 based on the temperature information of the ACF 10 transmitted by the temperature calculation unit 68. This instruction includes an instruction for increasing the power of the laser beam and an instruction for decreasing the power of the laser beam. The temperature control unit 69 is controlled by a control device 70 that controls the overall operation of the bonding apparatus 100.

  FIG. 7 is a diagram illustrating the arrangement of the fixture 45 and the temperature detection unit 64 as viewed from the X direction.

  Referring to FIG. 7, in the plurality of fixtures 45, a plurality of collimating lenses provided in each fixture 45 are arranged in a line in the X direction (the lens 42 shown in FIG. 4 and the like, shown in FIG. 7). Each array of laser beams emitted is arranged so that the light gathers on the backup substrate 55, preferably on the upper surface of the liquid crystal display panel 1 placed on the backup substrate 55. Is done. As a result, parallel light trains (laser beam trains) emitted from a plurality of lenses provided in each fixture 45 can be concentrated on the ACF 10. Therefore, the ACF 10 can be heated at a high speed by causing the ACF 10 to absorb high-power light.

  Specifically, the plurality of fixtures 45 are arranged in a fan shape in a cross section perpendicular to the X direction centering on a parallel light condensing position on the backup substrate 55 (that is, a predetermined position on the upper surface of the backup substrate 55). .

  Note that a plurality of lenses (for example, eight lenses) arranged in each fixture 45 are arranged at equal intervals in the X direction (the direction perpendicular to the paper surface). Thereby, on the backup substrate 55, the plurality of laser beams respectively emitted from the plurality of lenses are aligned at a uniform pitch.

  FIG. 8 is a diagram for explaining a laser light irradiation region on the backup substrate 55. Referring to FIG. 8, the collimated laser beam forms circular spots (shown by broken lines) that overlap each other on the backup substrate 55. The plurality of spots are arranged at a uniform pitch. By overlapping the spots, it is possible to increase the power of light applied to the ACF. It should be noted that the power at the both ends of the region where the spots are overlapped is smaller than that at the center (because the number of overlapping spots is small). Since this portion is not used for heating the ACF, it is cut in advance by the X-direction movable light shielding member 56.

  The length in the X direction of the laser light irradiation area AR is adjusted by moving the X direction movable light shielding member 56 in the X direction.

  Referring to FIG. 8, the length in the Y direction of the irradiation area AR is adjusted by the Y-direction light shielding member 57 (strictly speaking, the inclined surface 55a of the backup substrate 55 shown in FIGS. 9 and 10 described later). Is done. As will be described later, although the Y-direction light shielding member 57 itself does not move, the Y-direction light shielding member 57 relatively moves by moving the fixture provided with the lens integrally in the Y direction. Therefore, the length of the irradiation area AR in the Y direction can be changed.

  The maximum size of the irradiation area AR defined by the X-direction movable light shielding member 56 and the Y-direction light shielding member 57 is the maximum size of the driver IC that can be mounted on the panel substrate.

  The driver IC is often rectangular. The long axis direction of the rectangle corresponds to the X direction, and the short axis direction corresponds to the Y direction.

  The Y-direction light shielding member 57 has an inclined surface 57a that is inclined with respect to the XY plane. That is, the ridge formed by the flat surface 57b on the ACF 10 side and the inclined surface 57a in the Y-direction light shielding member 57 has a knife edge shape.

  The backup substrate 55 also has an inclined surface that is in contact with the inclined surface 57a (the inclination angle with respect to the XY plane is the same as the inclination angle of the inclined surface 57a). Note that this inclination angle is such that when a part or all of the laser beam from any fixture hits the inclined surface in the figure, it is totally reflected or after passing through the inclined surface. The angle is determined in consideration of refraction so as not to be incident on the ACF or the like disposed in the area. Further, the inclination angle of the inclined surface is compared with the direction in which the laser beam emitted from the fixture (indicated by reference numeral 45a) located on the most negative side in the Y direction among the fixtures arranged in a fan shape is directed to the backup substrate 55. Thus, the angle is further determined along the Y direction. As a result, with respect to the laser beam emitted toward the position excluding the portion blocked by the inclined surface 57 on the backup substrate 55, the laser beam from any fixture is not affected by the inclined surface 57a in the same manner. Thus, it is possible to avoid a situation in which a fixture having a negative position in the Y direction can emit more laser beams.

  The inclined surface may be a rough surface. In this case, when a part or all of the laser beam hits the inclined surface, the laser beam is diffused and weakened. Therefore, as described above, the total reflection angle or the ACF disposed on the inclined surface after passing through the inclined surface. Therefore, there is no need to consider a refraction angle that does not enter the light.

  A light-shielding knife edge made of a ceramic member for functioning as a Y-direction light-shielding member is disposed so that the upper surface of the backup substrate 55 is equal to the upper surface so as to fit into the position cut out by the inclined surface 57a.

  The temperature detector 64 is provided obliquely below the ACF 10. In addition, a plurality of temperature detectors 64 are provided in order to detect temperatures at a plurality of locations in the laser light irradiation area of the ACF 10. Although not shown, the temperature detector 64 is provided with the above-described thermopile (which may be a heat ray camera or a photodiode).

  A filter 64f is provided on the front surface of the temperature detection unit 64, that is, the surface on which electromagnetic waves radiated from the ACF 10 are incident. The filter 64f is provided so as not to transmit the scattered (or reflected) laser light and to transmit only the electromagnetic wave radiated from the ACF 10. For example, the filter 64f is a filter configured to transmit an electromagnetic wave having a wavelength band of 1.2 μm to 1.5 μm.

  A cylinder 64b is attached in front of the filter 64f. The directivity of the electromagnetic wave radiated from the ACF 10 can be controlled by the cylinder 64b.

  In the case where there is no influence of disturbance such as scattered (or reflected) laser light, the temperature detection unit 64 can be provided below the backup substrate 55. However, in this case, anhydrous quartz having a smaller number of hydroxyl groups than ordinary quartz is particularly preferable as a material for the backup substrate 55. When the ACF 10 is heated, the temperature of the ACF 10 reaches about 250 ° C., for example. In this case, an electromagnetic wave having a wavelength longer than 2 μm is radiated from the ACF 10. By using anhydrous quartz as the material of the backup substrate 55, it is possible to suppress the absorption of light in the wavelength band near 2.5 μm corresponding to the absorption band of the hydroxyl group, so that accurate temperature detection becomes possible.

  FIG. 9 is a diagram for illustrating a configuration of a beam shaping unit included in bonding apparatus 100 according to the present embodiment.

FIG. 9A is a diagram illustrating the X-direction movable light shielding member.
FIG. 9B illustrates the Y-direction light shielding member.

  With reference to FIGS. 9A and 9B, shaping of the laser beam LB in the X direction is realized by the X-direction movable light shielding member 56. FIG. That is, the X-direction length of the irradiation region of the laser beam (laser beam LB) in the ACF 10 is adjusted by the X-direction movable light shielding member 56.

  On the other hand, the shaping of the laser beam LB in the Y direction is cut out by the inclined surface (inclined surface 55a in contact with the inclined surface 57a of the Y direction light shielding member 57) and the inclined surface 57a as the Y direction light shielding member 57. This is realized by either or both of the light-shielding knife edge and the ceramic member fitted in the position. That is, the backup substrate 55 not only functions as an indicating member of the liquid crystal display panel 1 but also functions as a shutter for shaping the laser beam LB in the Y direction. As can be seen from FIGS. 7 and 9, the inclined surface 55a is in the Z direction on the backup substrate 55 (from the bottom surface opposite to the top surface facing the liquid crystal display panel 1 to the top surface). On the other hand, the slope is inclined in the Y direction.

  As shown in FIG. 7, the fixture 45 is tilted in the Z-axis direction about the X-direction axis. If shaping of the laser beam in the Y direction is performed below the backup substrate 55, there is a high possibility that the accuracy in the Y direction of the laser beam irradiation area in the ACF 10 cannot be ensured. For this reason, the accuracy of the irradiation region in the Y direction can be ensured by shaping the laser beam in the Y direction at a position very close to the ACF 10, that is, on the upper surface of the backup substrate 55.

  The inclined surface 55a is a rough surface (which can also be called a sand surface or a satin surface) by processing such as sandblasting or etching. For example, when the laser light reaching the inclined surface 55a is emitted from the inclined surface 55a to the outside of the backup substrate 55, the laser light is scattered (diffused) on the inclined surface 55a. Further, the light scattered outside the backup substrate 55 is scattered multiple times by the Y direction light shielding member 57 or absorbed by the Y direction light shielding member 57. The liquid crystal display panel 1 is provided with heat-sensitive components such as a polarizing plate 7. The Y-direction light shielding member 57 can avoid irradiating such a heat-sensitive component with high-power laser light.

  Note that the edge position Pe of the Y-direction light shielding member 57 (that is, the position of the tip of the knife edge) is the same position as the edge of the silicon chip (driver IC 5) or the position where it enters the silicon chip side. Further, the upper surface of the backup substrate 55 is at the same height as the upper surface (plane 57 b) of the Y-direction light shielding member 57 or higher than the upper surface of the Y-direction light shielding member 57.

  The X-direction movable light shielding member 56 and the Y-direction light shielding member 57 are made of ceramic, for example.

  FIG. 10 is a schematic diagram for explaining shaping of the laser beam in the Y direction by the backup substrate 55. In FIG. 10, for convenience of explanation, the inclined surface 55a is represented as a plane.

  Referring to FIG. 10, the laser light transmitted through optical fiber 41 is emitted from lens 42 provided in lens holder 43 and is refracted at the interface between air and backup substrate 55. The laser light travels inside the backup substrate 55 and reaches the inclined surface 55a. Since the incident angle θ of the laser beam with respect to the perpendicular of the inclined surface 55a is larger than the total reflection angle, the laser beam is totally reflected by the inclined surface 55a.

  FIG. 11 is a diagram for explaining a semiconductor laser used as the laser light source 32. Referring to FIG. 11, there are two types of semiconductor lasers, a multi-emitter type semiconductor laser and a single-emitter type semiconductor laser. FIG. 11A shows a multi-emitter semiconductor laser. Referring to FIG. 11A, a semiconductor laser 32a is a semiconductor chip having a plurality of emitters EM for outputting laser light. Therefore, the power of light output from one semiconductor chip can be increased.

  FIG. 11B is a diagram for explaining problems that may occur in a multi-emitter semiconductor laser. Referring to FIG. 11B, when damage (for example, a crystal defect is considered) occurs in one of the plurality of emitters EM (or a peripheral region thereof), the damage is transmitted to the other emitters. It is possible.

  FIG. 11C shows a single-emitter semiconductor laser. Referring to FIG. 11C, the semiconductor laser 32b has one emitter EM. For example, many semiconductor laser chips are configured to output laser light from a cleaved surface of a crystal. In such a semiconductor laser chip, the two opposing surfaces are cleaved surfaces. Therefore, laser light is output from both of the two surfaces. However, what is extracted as output light is light emitted from one of the two surfaces. Therefore, in this embodiment, a semiconductor laser that outputs laser light from a cleavage plane of a crystal is included in a single-emitter semiconductor laser.

  In the case of a single-emitter semiconductor laser, the power of light output from each semiconductor laser is smaller than the power of light output from a multi-emitter semiconductor laser. Therefore, in the case of a single-emitter semiconductor laser, it is considered that the number necessary for obtaining power necessary for heating the ACF is larger than that of a multi-emitter semiconductor laser. However, in the case of a single-emitter semiconductor laser, even if any one of the plurality of laser light sources 32 breaks down, only the target laser light source needs to be replaced, so that maintainability is excellent. Even if the output light power varies among the plurality of laser light sources 32, the plurality of laser light sources 32 can be individually controlled (drive current is controlled for each laser light source 32). That is, the light output can be controlled in units of emitters. This makes it possible to generate a beam with a uniform power sufficient for bonding. Therefore, in this embodiment, a single emitter semiconductor laser is used as a laser light source.

FIG. 12 is a view for explaining the pressure head 25 shown in FIG.
FIG. 12A is a schematic diagram showing the configuration of the pressure head 25 and its periphery. With reference to FIG. 12A, the pressure head 25 includes pressing members 25 a and 25 b provided at the tip of the cylinder 20. The holding members 25a and 25b are made of a material having a lower thermal conductivity than silicon, which is the main material of the driver IC 5. By using a material having lower thermal conductivity than silicon for the pressing members 25 a and 25 b, it is possible to suppress the heat of the driver IC 5 from escaping to the cylinder 20. As a result, the temperature drop of the driver IC 5 can be prevented, and the temperature drop of the ACF 10 provided under the driver IC 5 (silicon chip) can also be prevented.

  Further, in order to apply pressure to the driver IC 5, the pressing members 25a and 25b must be formed of a material having an appropriate hardness. From the above points, the material of the pressing members 25a and 25b is selected from materials including ceramic, quartz, and glass.

  The plurality of suction holes 23 are formed so as to penetrate the pressing members 25a and 25b. The vacuum suction unit 77 vacuum-sucks the driver IC 5 that is the object through the plurality of suction holes 23. Therefore, the surface of the driver IC 5 (the surface opposite to the surface on which the bump electrodes are formed) is in close contact with the pressing member 25a. By bringing the driver IC 5 into close contact with the pressing member 25a, the pressure applied to the driver IC 5 can be made uniform within the contact surface of the driver IC 5 that contacts the pressing member 25a.

  By applying pressure evenly to the surface of the driver IC 5, it is possible to prevent the problem that the position of the electrode on the driver IC side is deviated from the position of the electrode on the liquid crystal display panel side. Thereby, joining can be performed with high accuracy.

  The vacuum suction unit 77 is controlled by a control device 70 (not shown). Moreover, the vacuum suction part 77 returns the pressure of the suction hole 23 to atmospheric pressure, for example, by supplying compressed air to the suction hole 23 at the end of the vacuum suction.

  A valve 24 is provided in each of the plurality of suction holes 23. The vacuum suction unit 77 determines the suction hole 23 to be used corresponding to the size (chip size) of the driver IC. The valve 24 provided in the used suction hole 23 is opened, and the valve 24 provided in the unused suction hole 23 is closed. The vacuum suction unit 77 determines an open valve and a closed valve according to the size of the driver IC.

  As shown in FIG. 12B, the bottom surface of the pressing member 25a is larger than the surface of the driver IC. Therefore, an open valve and a closed valve can be determined according to the size of the driver IC.

  The bottom surface of the pressing member 25a and the surface of the driver IC may be the same size. FIG. 12C is a diagram for explaining the lengths of the pressing member 25a and the driver IC 5 in the X direction, and FIG. 12D is a diagram illustrating the lengths of the pressing member 25a and the driver IC 5 in the Y direction. FIG. As shown in FIGS. 12C and 12D, the bottom surface of the pressing member 25a and the surface of the driver IC are the same size. However, when the bottom surface of the pressing member 25a deviates from the surface of the driver IC, it is conceivable that pressure is not uniformly applied to the surface of the driver IC 5. Therefore, as shown in FIG. 12B, the bottom surface of the pressing member 25a is preferably larger than the surface of the driver IC.

  FIG. 13 is a block diagram for illustrating a control system of bonding apparatus 100 according to the present embodiment.

  Referring to FIG. 13, laser control unit 35, temperature calculation unit 68, and temperature control unit 69 operate according to direct or indirect instructions from control device 70.

  The laser control unit 35 includes a temperature detection circuit 35a, a control circuit 35b, a memory 35c, and an interface (shown as I / F in FIG. 13) circuit 35d. The temperature detection circuit 35a detects the temperature of each of the plurality of laser light sources 32 or the entire temperature (for example, ambient temperature), and outputs the detected temperature to the control circuit 35b. The memory 35c stores information for operating the laser light source 32. This information includes, for example, information on the operating temperature of each of the plurality of laser light sources 32 or the upper limit value of the entire temperature, information indicating the relationship between the operating current value of the laser light source and the light output, and the like.

  The control circuit 35b reads information on the upper limit value of the operating temperature from the memory 35c and receives the detection result (current operating temperature) of the temperature detection circuit 35a. When the current operating temperature exceeds the upper limit value, the control circuit 35b controls each power source 36 by controlling the power supply device 36, for example, stopping light output by all or part of the plurality of laser light sources 32. Control the driving conditions independently. The laser light source 32 is cooled by the laser cooling device 34 so that the operating temperature of the laser light source 32 does not exceed the upper limit value.

  In addition, the control circuit 35b receives an instruction for increasing the power of the laser light applied to a part or the whole of the ACF 10 (or an instruction for decreasing the power of the laser light) from the interface circuit 35d. The control circuit 35b controls the power supply device 36 in accordance with the instruction to increase or decrease the current supplied to some or all of the plurality of laser light sources 32. Are controlled independently. This control includes control for making the intensity of laser light emitted from each laser light source 32 constant with respect to time, or control for changing with time.

  According to this configuration, light from a laser light source that can be controlled under independent driving conditions is transmitted to a certain region on the backup substrate 55 as shown in FIG. 8 via an optical system such as a fiber or a lens. In this way, irradiation is performed as a group of a plurality of laser beams irradiated to different positions, so that it is possible to control the intensity distribution and temporal change in intensity of the laser beams irradiated to this region.

  The temperature calculation unit 68 receives a signal output from each of a plurality of temperature sensors 64a (for example, three temperature sensors 64a as shown in FIG. 13) provided in the temperature detection unit 64. The temperature calculation unit 68 includes an A / D (analog-digital) conversion circuit 68a, an arithmetic circuit 68b, a memory 68c, and an interface circuit 68d. The A / D conversion circuit 68a converts the signal (analog signal) received from the temperature sensor 64a into a digital signal. The memory 68c stores information indicating the correspondence between the temperature and the numerical value indicated by the digital signal. The arithmetic circuit 68b reads out information on the correspondence relationship between the temperature and the numerical value indicated by the digital signal from the memory 68c and receives the digital signal from the A / D conversion circuit 68a. The arithmetic circuit 68b calculates the current temperature of the ACF 10 and outputs the calculation result to the interface circuit 68d. The interface circuit 68d outputs the temperature information to the temperature control unit 69. Note that the temperature information output from the arithmetic circuit 68b to the interface circuit 68d is the temperature information detected by each of the plurality of temperature sensors 64a.

  The temperature control unit 69 includes an arithmetic circuit 69a and interface circuits 69b and 69c. The interface circuit 69b receives the temperature information of the ACF 10 output from the interface circuit 68d and outputs the information to the arithmetic circuit 69a.

  The arithmetic circuit 69a generates information related to the temperature distribution of the ACF 10 based on the information received from the interface circuit 69b. Based on the temperature distribution information, the arithmetic circuit 69a identifies a portion in the surface of the ACF 10 where the temperature needs to be increased (or decreased). For example, when the temperature of the ACF 10 is generally low, the arithmetic circuit 69a determines that the temperature needs to be increased in all portions in the plane of the ACF 10. Then, the arithmetic circuit 69a outputs the arithmetic result to the interface circuit 69c.

  The interface circuit 69c outputs the calculation result of the calculation circuit 69a to the laser control unit 35. The information output from the interface circuit 69c is received by the interface circuit 35d and sent from the interface circuit 35d to the control circuit 35b.

  The control device 70 receives information on the temperature distribution of the ACF 10 from the temperature control unit 69 (arithmetic circuit 69a) and instructs the temperature control unit 69 to operate / stop. For example, the control device 70 outputs information related to the temperature distribution of the ACF 10 to the display device 80 and causes the display device 80 to display the information.

  Further, the control device 70 controls an arm moving device 62a for moving the arm 62 to which the camera 60 (see FIG. 4) is attached. The arm moving device 62a includes, for example, a motor, a gear, a motor driver 75 shown in FIG. That is, the arm 62 and the arm moving device 62a shown in FIG. 13 constitute a camera moving mechanism for moving the camera 60.

  Further, the control device 70 controls the optical system moving device 51a for moving the support member 51 (see FIG. 4) to which the fixture 45 is attached in the Y direction, and moves the X direction movable light shielding member 56 in the X direction. The X-direction movable light shielding member driving unit 56a for moving is controlled. As a result, the laser beam is shaped into a predetermined shape in the ACF 10. Further, the control device 70 controls the operation of the vacuum suction unit 77.

  The storage device 82 (for example, a hard disk) stores a program executed by the control device 70, a processing result of the control device 70, and the like in a nonvolatile manner.

[Bonding process]
FIG. 14 is a flowchart for explaining the entire joining process for joining the liquid crystal display panel 1 and the mounting component via the ACF 10. In the following description, the IC driver 5 (bare chip) is exemplified as the “mounting component”, but the same processing is executed when the “mounting component” is a TCP or other electronic component that can be joined.

  Referring to FIG. 14, when the process is started, first, in step S1, liquid crystal display panel 1 is carried in. Next, in step S2, a cleaning process of an extraction electrode (hereinafter also referred to as a panel electrode) provided on the glass substrate of the liquid crystal display panel 1 is performed. Subsequently, in step S3, the ACF that is the connection material is positioned, and the ACF is attached to the determined position.

  In step S4, the component mounted on the liquid crystal display panel 1, that is, the IC driver 5, is picked up from the chip tray 21 by the cylinder 20 or the like (see FIG. 4).

  In step S <b> 5, the arm 62 to which the camera 60 is attached slides in the lower part of the back-up board 55. As shown in FIG. 13, the control device 70 controls the arm moving device 62a, so that the arm 62 moves. As a result, the camera 60 moves to a predetermined position below the back substrate 55.

  In step S <b> 6, the camera 60 photographs the panel electrode and the bump electrode of the driver IC 5 through the backup substrate 55 and the glass substrate of the liquid crystal display panel 1. Based on the image photographed by the camera 60, the mounting component (more specifically, the bump electrode) is positioned with respect to the panel electrode, and the corresponding electrodes are aligned with each other between the panel electrode and the bump electrode.

  In step S7, the pressure head 25 is lowered as the cylinder 20 is lowered. As a result, the driver IC 5 (and the ACF 10) is pressurized, and the ACF 10 is sandwiched between the liquid crystal display panel 1 and the driver IC 5.

  In step S8, the ACF 10 is irradiated with laser light. As a result, the ACF 10 is heated, and when the temperature of the ACF 10 reaches a certain temperature, the thermally reactive resin in the ACF 10 fluidizes. Furthermore, since the ACF 10 is pressurized, the microparticles are in contact with each other inside the ACF 10. As a result, the electrode of the driver IC 5 and the panel electrode are electrically connected via the microparticle. Furthermore, the heat-reactive resin is cured by continuing to heat the ACF 10. Note that the pressure applied to the driver IC 5 in step S8 may be constant or may be changed as appropriate.

  In step S9, the cylinder 20 (pressure head 25) is raised. As a result, the pressure of the driver IC 5 (ACF 10) is released.

  In step S10, the mounting portion is inspected. This inspection is, for example, an electrical connection inspection, an appearance inspection, or the like.

  In step S11, the liquid crystal display panel 1 is unloaded for processing in the next process (for example, an assembly process). When the process of step S11 ends, the entire process ends.

  Next, the laser beam irradiation process that is a part of the process of step S8 will be described in more detail. FIG. 15 is a flowchart for explaining the laser beam irradiation process.

  Referring to FIG. 15, the laser light irradiation process includes a process at a stage before laser light is actually irradiated on ACF 10 (step S20) and a process when laser light is irradiated onto ACF 10 (step S21). To S27).

  First, the process of step S20 will be described. Step S20 includes substeps S20A to S20E. In step S20A, a target temperature distribution on the surface of the ACF 10 and a heating time are set. For example, the user inputs such information into the input device. The control device 70 acquires information from the input device. Thereby, the temperature distribution and the heating time are set. These pieces of information may be sent from the control device 70 to the temperature control unit 69 (see FIG. 13).

  Referring to FIGS. 15 and 13, in step S20B, a temperature holding feedback coefficient is set. While the ACF 10 is irradiated with the laser light, the power of the laser light is adjusted by the control device 70, the temperature control unit 69, and the laser control unit 35 in order to keep the temperature of the ACF 10 at the set temperature. This process is feedback control for controlling the power of the laser beam based on the difference between the temperature of the ACF 10 and the set temperature. In this control, the correction amount of the power of the laser beam is calculated based on a value obtained by multiplying a coefficient that is a difference between the temperature of the ACF 10 and the set temperature. The temperature control unit 69 sets the coefficient in step S20B. The control device 70 may set a feedback coefficient.

  In step S20C, the laser control unit 35 sets an initial output value of the laser beam based on the set feedback coefficient. In step S20D, the laser control unit 35 sets a laser light source to be operated among the plurality of laser light sources 32 based on the set output value.

  In step S20E, the control device 70 moves the X-direction movable light shielding member 56 by controlling the X-direction movable light shielding member driving unit 56a. Further, the control device 70 controls the optical system moving device 51a to move the Y-direction light shielding member 57 relative to the fixed portion 53 (see FIG. 4) to which the fixture 45 is fixed.

  Next, in step S <b> 21, the laser control unit 35 controls the power supply device 36 to output laser light having a set output value (laser initial output value) from the laser light source 32 to be operated. Further, the plurality of temperature sensors 64 a provided in the temperature detection unit 64 detect the temperature of the ACF 10.

  In step S22, the temperature calculation unit 68 acquires the output of each of the plurality of temperature sensors 64a. The temperature calculation unit 68 calculates the temperature of the ACF 10 based on the output of the temperature sensor 64 a and outputs the calculation result (information on the temperature of the ACF 10) to the temperature control unit 69.

  In step S <b> 23, the temperature control unit 69 receives information on the temperature of the ACF 10 calculated by the temperature calculation unit 68. Thereby, the temperature control unit 69 acquires information on the temperature distribution of the ACF 10.

  In step S24, the temperature control unit 69 compares the target temperature distribution set in step S20A with the temperature distribution acquired in step S23. Then, the temperature control unit 69 outputs the comparison result of these temperature distributions to the laser control unit 35. The laser control unit 35 calculates the feedback amount of the output of the laser light source based on the comparison result (difference in temperature distribution). For example, if there is a difference between the target temperature and the actual temperature in a certain part of the ACF 10, the laser control unit 35 calculates a feedback amount corresponding to the temperature difference.

  In step S25, the laser control unit 35 corrects the output from the laser light source based on the calculated feedback amount. In the case of the above-described example, the laser control unit 35 specifies the laser light source that irradiates the laser light to the portion of the ACF 10 where the difference between the target temperature and the actual temperature is generated. Then, the laser control unit 35 controls the power supply device 36 so as to increase the output of the specified laser light source by the feedback amount. The power supply device 36 increases the output of the laser light source by increasing the current supplied to the laser light source.

  In step S <b> 26, the laser control unit 35 determines whether or not the heating time of the ACF 10 (in other words, the time for which the ACF 10 is irradiated with laser light) exceeds a predetermined elapsed time. If the heating time of ACF 10 is equal to or shorter than the predetermined elapsed time (NO in step S26), the process returns to step S22. On the other hand, when the heating time of ACF 10 exceeds the predetermined elapsed time (YES in step S26), in step S27, laser control unit 35 completes the laser light irradiation by laser light source 32. When the process of step S27 ends, the entire process ends.

  FIG. 16 is a diagram showing a laser light irradiation area AR when a bare chip (driver IC 5) is mounted on the liquid crystal display panel 1. In the following, “irradiation range” means a range in the one-dimensional direction (X direction or Y direction) of the irradiation area AR.

  FIG. 16A is a diagram showing an irradiation area AR of laser light viewed from the bare chip (driver IC 5) side.

  FIG. 16B is a diagram illustrating an irradiation range in the X direction of laser light viewed from the side of the bare chip (driver IC 5) and the liquid crystal display panel 1.

  Referring to FIG. 16, the position of driver IC 5 is determined so that bump electrode 5 a of driver IC 5 overlaps with panel electrode 1 a of liquid crystal display panel 1. The ACF 10 is sandwiched between the bump electrode 5 a of the driver IC 5 and the panel electrode 1 a of the liquid crystal display panel 1.

  The laser light irradiation area AR is substantially the same as the area determined by the contour of the driver IC 5. In other words, the laser beam is applied to an area that substantially matches the driver IC 5. As shown in FIG. 8, such laser light irradiation is realized by combining laser beams (light spots) with a uniform pitch and a light shielding member in the X direction and the Y direction.

  FIG. 17 is a diagram for explaining that the state of the thermally reactive resin in the ACF changes depending on the temperature of the resin.

  Referring to FIG. 17, the horizontal axis of the graph indicates the elapsed time from the start of ACF heating, and the vertical axis of the graph indicates the temperature. The thermoreactive resin described here is a thermosetting resin, and fluidization thereof starts when the temperature of the thermoreactive resin reaches the reaction start temperature. Actually, the reaction (fluidization and curing) of the heat-reactive resin proceeds little by little from a temperature slightly lower than the reaction start temperature. For convenience of explanation, here, when the temperature of the resin reaches the reaction start temperature, Fluidization shall begin. In addition, it is necessary to consider time restrictions regarding the thermal reaction of the thermosetting resin. However, FIG. 17 is a schematic diagram used for facilitating understanding of the state change of the thermosetting resin due to temperature, and does not consider such time constraints.

  When the temperature of the thermally reactive resin does not reach the reaction start temperature, the resin does not fluidize. Further, when the temperature of the heat-reactive resin rapidly rises and reaches the heat resistant temperature of the resin, the curing of the resin proceeds rapidly. In these cases, it is considered difficult to form a conductive path between the panel electrode 1a and the bump electrode 5a because the ACF is not easily thinned even when the ACF is pressurized. Therefore, it is considered necessary to pressurize the ACF while fluidizing the resin once and maintaining the fluidized state for a certain period of time. The intensity of the laser beam irradiated to the irradiation area AR shown in FIG. 16 is determined in consideration of such a change in temperature with respect to the heating time.

  Note that the area determined by the outline of the driver IC 5 and the laser light irradiation area AR do not have to coincide exactly. For example, if the thermal reaction of the resin contained in the ACF 10 proceeds substantially simultaneously in the central portion and the peripheral portion of the region determined by the contour of the driver IC 5, the laser light irradiation region AR is as shown in FIG. The area may be smaller than the area determined by the outline of. However, if the laser light irradiation area AR is not an appropriate size, various problems may occur in heating the ACF by the laser light.

  FIG. 18 is a diagram for explaining a problem that may occur when the irradiation area AR of the laser beam is not appropriate.

  FIG. 18A is a diagram for explaining a problem that may occur when some of the plurality of bump electrodes 5a are not included in the laser light irradiation area AR. Referring to FIG. 18 (a), the range irradiated with the laser beam becomes high temperature in a relatively short time, so that the heat-reactive resin in ACF 10 is fluidized and bump electrode 5a and panel are pressed by ACF 10 pressurization. The electrical connection with the electrode 1a and the curing of the thermally reactive resin are smoothly performed. However, since the temperature of the portion outside the laser light irradiation region in the ACF 10 is lower than the temperature of the portion directly irradiated with the laser light, there is a high possibility that the fluidization of the thermally reactive resin will be insufficient. Therefore, even if pressure is applied to the driver IC 5 from above the driver IC 5, the thickness of this portion hardly changes, so that the electrical connection between the bump electrode 5a and the panel electrode 1a may be insufficient.

  FIG. 18B is a diagram for considering problems that may occur when the laser light irradiation area AR is larger than the area determined by the contour of the driver IC 5. In this case, according to the experimental result, a phenomenon in which the ACF around the contour of the driver IC 5 is burnt was observed. Referring to FIG. 18B, in the portion of ACF 10 that is in contact with bump electrode 5a (or in the vicinity of bump electrode 5a), the conductive particles contained in ACF 10 absorb the light and generate heat by laser light irradiation. However, it is considered that the heat is transmitted not only to the inside of the ACF 10 but also to the bump electrode 5a. However, when there is a portion irradiated with only the ACF 10 in the laser light irradiation area AR, the ACF 10 is abnormally heated by the heat generated using the conductive particles as the heat source, and the temperature rapidly rises. To do. Thereby, it can be considered that, for example, the heat-reactive resin in the ACF 10 is rapidly cured or burnt. Further, it is conceivable that outgas is generated in that portion. Also in this case, since a lump of ACF is generated in the outline of the driver IC 5, even if pressure is applied to the driver IC 5 from above the driver IC 5, the thickness of this portion hardly changes. Therefore, the bump electrode 5a and the panel electrode 1a There is a possibility that the electrical connection with is insufficient.

  Therefore, in the present embodiment, as shown in FIG. 16, the laser light irradiation area AR is set to an area substantially equal to the area determined by the contour of the driver IC. Thereby, the reliability of the electrical connection between the bump electrodes of the driver IC by the ACF 10 and the panel electrodes of the liquid crystal display panel 1 can be enhanced. Further, by concentrating the laser beam on this portion, the portions corresponding to all the electrodes in the ACF are fluidized simultaneously. Therefore, the bonding can be performed in a short time by pressurizing the driver IC and the ACF.

  Note that even if the laser light irradiation area AR is larger than the area determined by the contour of the driver IC, if the intensity of the laser light outside the contour of the driver IC is lower than the intensity of the laser light in the contour of the driver IC, the above-mentioned The problem of rapid curing and scorching will not occur. Accordingly, the laser light irradiation area AR referred to here refers to a laser light irradiation area having a strength that substantially affects the fluidization and hardening of the ACF during bonding.

  Even if the laser beam is shaped by the Y-direction light-shielding member by the X-direction movable light-shielding member, the laser beam is slightly irradiated to the area outside the laser light irradiation area AR due to the spatial spread of the laser beam. it is conceivable that.

  FIG. 19 is a diagram schematically showing a spatial distribution of the power of laser light. In FIG. 19, “+ X direction” and “−X direction” correspond to the X direction shown in FIG. 8. In this embodiment, a laser light irradiation region is a range in which a power of a certain ratio or more with respect to the total power of the laser light emitted from the laser light irradiation unit shown in FIG. In the present embodiment, this ratio is 90%.

  Note that the flat portion at the top of the curve shown in FIG. 19 is not limited to the fact that the power of the laser beam is completely constant, and the bonding of the display panel electrode and the bonding target electrode by ACF. If the power that enables the above is obtained, noise may be superimposed on the top portion.

  Next, the reason why the wavelength of the laser beam is set in the range of 600 nm to 1100 nm will be described.

  FIG. 20 is a diagram for explaining the relationship between the penetration depth of light into aluminum and silicon and the wavelength of the light.

  The wavelength range of light in the graph shown in FIG. 20 is in the range of 200 nm to 1400 nm. In this range, the longer the wavelength of light, the greater the penetration depth of the light into silicon.

  On the other hand, the penetration depth of light into aluminum is greatest when the wavelength is around 800 nm. Here, the penetration depth of an object means a distance at which the power of laser light that has entered the object is attenuated to 1 / e (e is a natural logarithm) with reference to the surface of the object.

  In the present embodiment, the wavelength of the laser light is selected from the range from 600 nm to 1100 nm. The reason for this is as follows. In many cases, the panel electrode is formed of a thin film mainly composed of aluminum. Part of the laser light passes through the backup substrate 55 and the liquid crystal display panel 1 and reaches the panel electrode. In order to heat the ACF 10 with laser light and minimize damage to the panel electrode, it is preferable that the laser light reaching the panel electrode is transmitted through the electrode. Therefore, although the wavelength of the laser beam depends on the thickness of the panel electrode, the penetration depth is preferably larger than the thickness of the panel electrode. For this reason, as the wavelength of the laser light, a wavelength having a light penetration depth as large as possible is selected. A wavelength of 600 nm or more is selected as a wavelength that can satisfy such a condition.

Next, in the wavelength range of 600 nm to 1100 nm, the ACF light absorption rate is relatively small (for example, 5%). Therefore, in this embodiment, silicon that is the main material of the driver IC is heated by laser light. As a result, the ACF absorbs the laser light and generates heat, and the ACF is heated by the silicon heated by the laser light transmitted through the ACF. Therefore, it becomes possible to raise the temperature of ACF in a short time. For this purpose, it is necessary to select the wavelength of the laser beam so that the laser beam does not pass through the silicon. As shown in FIG. 20, the width of the thickness of the silicon chip is about 0.5 to 1 mm (1 × 10 ⁶ (nm)). Therefore, a wavelength of 1100 nm or less is selected as a wavelength that can satisfy such a condition.

  Further, the ACF can be cured in a short time by concentrating the heat source as much as possible under the silicon chip (boundary between the ACF and the silicon chip). However, if the heat is concentrated too much, the silicon chip will be damaged. In addition, since light having a short wavelength has high photon energy, there is a problem in durability of the semiconductor laser element itself. For this reason, it is preferable to use light having a wavelength as long as possible.

  For the above reasons, a wavelength of 600 nm or more and 1100 nm or less is selected as the wavelength of the laser beam.

  In the above description, a case where a bare chip (driver IC) is bonded to the liquid crystal display panel 1 via the ACF is illustrated. However, the bonding apparatus and method of the present embodiment can also be applied when TCP is bonded to the liquid crystal display panel 1 via the ACF.

  FIG. 21 is a diagram showing an irradiation area AR of the laser beam when the lead conductor 2b provided on the TCP 2 is connected to the electrode on the liquid crystal display panel 1 through the ACF.

FIG. 21A is a diagram showing a laser light irradiation area AR viewed from the TCP 2 side.
FIG. 21B is a diagram illustrating the irradiation range in the X direction of laser light viewed from the side surface side of the TCP 2 and the liquid crystal display panel 1. For convenience of illustration, the liquid crystal display panel 1 is not shown in FIG.

  Referring to FIG. 21, the irradiation area AR is set so that the irradiation area AR is substantially equal to the area determined by the contour of the carrier tape 2a of TCP2. Specifically, the irradiation area AR includes the lead conductor 2b and is set so as not to protrude from the overlapping range of the TCP2 carrier tape 2a and the ACF10. That is, also in the case of mounting using TCP, the irradiation area AR is determined in the same manner as in the case of mounting a bare chip. Further, the definition of the irradiation area AR is a range in which a power of a certain ratio (for example, 90%) or more is obtained with respect to the total power of the laser light emitted from the laser light irradiation unit as shown in FIG. The arrangement direction of the plurality of lead conductors 2b corresponds to the X direction shown in FIG.

  Polyimide, which is the main component of the carrier tape included in TCP2, easily absorbs light having a wavelength in the range (600 nm to 1100 nm) shown in FIG. Therefore, as in the case of the bare chip, not only the ACF 10 generates heat by the laser light, but also the TCP carrier tape is heated by the laser light transmitted through the ACF 10. As a result, the temperature of the ACF can be raised in a short time.

  In addition, when the laser beam is applied to the boundary region between the carrier tape 2a and the ACF 10 (or the region outside the boundary), the resin in the ACF 10 is damaged. Therefore, by determining the irradiation area AR as shown in FIG. 21, the reliability in mounting the TCP 2 on the liquid crystal display panel 1 can be increased.

  As described above, according to the present embodiment, the bonding apparatus 100 includes the laser light irradiation unit that irradiates the ACF 10 with the laser light for heating the ACF 10. The laser beam irradiating unit controls the plurality of laser light sources 32 and the intensity of the laser beams emitted from the plurality of laser light sources 32 so as to be constant or change with time independently of each other. Part 35. And the joining apparatus 100 irradiates the laser beam emitted from each of the plurality of laser light sources to different positions on the surface of the joining object on which the plurality of electrodes are formed, so that the contour of the joining object is obtained. The whole area of the determined area is irradiated with laser light.

  The ACF 10 can be uniformly heated in the laser light irradiation region described above. As a result, the ACF can be heated in a short time, and the entire irradiation region can be fluidized uniformly. As a result, a plurality of electrodes to be joined can be joined to a plurality of electrodes on the liquid crystal display panel by a single pressurizing process including provisional crimping and permanent crimping, so that high-speed joining is possible.

  Further, by uniformly fluidizing the entire irradiation region, when a bonding target (bare chip or TCP) is pressurized, a plurality of electrodes of the bonding target are electrically connected to a plurality of electrodes on the liquid crystal display panel, respectively. It is possible not only to make an electrical connection, but also to ensure the electrical connection. Thereby, for example, the yield of the liquid crystal display panel can be improved.

Therefore, according to this embodiment, the productivity of the display device can be improved.
(Modification)
FIG. 22 is a view showing a modified example of the backup substrate 55. Referring to FIGS. 22 and 9, the configuration according to this modification is different from the configuration shown in FIG. 9 in that a laser light absorber 58 is further provided around backup substrate 55. The laser light absorber 58 is provided in the reflection direction of the laser light (laser beam LB) reflected on the inclined surface 55 a of the backup substrate 55. The laser light absorber 58 is an absorber that can reflect the laser light reflected from the inclined surface 55 a and emitted from the backup substrate 55. For example, the laser light absorber 58 is made of ceramic.

  By arranging the laser light absorber 58 as shown in FIG. 22, it is possible to reduce the influence of the laser light scattered by the backup substrate 55 on the surroundings. According to this modification, since the scattered laser light can be absorbed by the laser light absorber 58, the influence of the laser light around the backup substrate 55 can be avoided.

  The surface 55b of the backup substrate 55 facing the laser light absorber 58 is a surface processed into a rough surface (which can be referred to as a sand surface or a satin surface) like the inclined surface 55a. Thereby, since the laser beam can be diffused on the surface 55b, it is possible to prevent the light having a high energy density from entering the laser beam absorber 58. Therefore, problems such as damage to the laser light absorber 58 can be avoided.

FIG. 23 is a view showing a modification of the pressure head 25 shown in FIG.
Referring to FIG. 23, a heat conductive material 25c having high heat conductivity is provided on the bottom surface of the pressing member 25a (that is, the surface in contact with the driver IC 5).

  For example, when considering the thermal gradient of the driver IC 5 in the Z direction, when the ACF 10 is heated, the surface of the driver IC 5 on the ACF 10 side becomes hotter than the surface of the driver IC 5 on the pressure head 25 side. Further, when considering the thermal gradient of the driver IC 5 in the X direction, heat easily escapes from the end of the driver IC 5 into the air, whereas the heat at the center of the driver IC 5 hardly escapes to the surroundings. Therefore, the temperature at the center of the driver IC 5 tends to be higher than the temperature at the periphery of the driver IC 5.

  As shown in FIG. 23, it is possible to reduce such a thermal gradient by providing a heat conductive material 25c on the bottom surface of the pressing member 25a. As a result, an effect of alleviating thermal stress to the driver IC (bare chip) and an effect of reducing the temperature distribution of the ACF during heating of the ACF can be expected. In addition, although the heat conductive material provided in the bottom face of the pressing member 25a is not specifically limited, DCL (Diamond Like Carbon; carbon thin film material similar to diamond) can be mentioned as an example.

FIG. 24 is a diagram illustrating an example of an optical system applicable to this embodiment.
Referring to FIG. 24, this optical system is shown in FIG. 4 and the like in that it further includes condenser lenses 101 and 102 and a shutter 103 in place of the X direction movable light shielding member 56 and the Y direction light shielding member 57. Different from the optical system. The configuration of the remaining part of the optical system is the same as that of the optical system described above.

  This optical system is an optical system that employs the Kohler illumination method. In the case of Koehler illumination, the irradiated surface can be illuminated uniformly even if the light source has uneven brightness. The irradiation area AR indicates an irradiation area of laser light that has passed through the backup substrate 55 and the liquid crystal display panel 1 and has entered the ACF 10. By making the light intensity uniform in this region, the temperature in this region can also be made uniform. In this optical system, the irradiation area AR is set to be substantially equal to the area determined by the contour of the drive IC 5.

FIG. 25 is a diagram showing another example of an optical system applicable to this embodiment.
Referring to FIG. 25, this optical system further includes an imaging lens 104 and an objective lens 105, and a shutter 103 in place of the X-direction movable light shielding member 56 and the Y-direction light shielding member 57. Different from the optical system shown in FIG. The configuration of the remaining part of the optical system is the same as that of the optical system described above.

  The imaging lens 104 and the objective lens 105 are cylindrical lenses. As a result, the laser beam (laser beam LB) is focused only in one axial direction. Further, the laser beam is made uniform by the diffuse spatial profile of the laser light. When the laser beam is focused by the shutter 103, the laser beam having a spatially uniform intensity distribution enters the imaging lens 104.

FIG. 26 is a diagram showing still another example of an optical system applicable to the present embodiment.
Referring to FIG. 26, this optical system further includes an fθ lens 106, a galvano mirror 107, and a rotation drive unit 108 that rotates the galvano mirror 107, and an X direction movable light shielding member 56 and a Y direction light shielding member 57. 4 is different from the optical system shown in FIG. The configuration of the remaining part of the optical system is the same as that of the optical system described above.

  The fθ lens 106 is selected from a telecentric type. Further, the fθ lens 106 is disposed so that the optical axis is perpendicular to the laser irradiation surface.

  In addition, according to this optical system, the laser beam LB can be alternately (or sequentially) guided to both of the two backup substrates 55 by rotating the galvanometer mirror 107 by the rotation driving unit 108. Therefore, for example, the TCP and the liquid crystal display panel can be joined via the ACF on one backup substrate 55, and the bare chip and the liquid crystal display panel can be joined via the ACF on the other backup substrate 55. . In this configuration, it is necessary to increase the intensity of the laser beam compared to the configuration of the optical system described above.

FIG. 27 is a diagram showing still another example of an optical system applicable to the present embodiment.
Referring to FIG. 27, in this optical system, an aspheric lens 42 a and a collimator lens 42 b for shaping laser light (laser beam) emitted from optical fiber 41 are provided corresponding to each optical fiber 41. By superimposing the laser light that has passed through the aspherical lens 42a and the collimating lens 42b with the ACF 10, it is possible to irradiate the irradiation area AR with laser light having sufficient intensity and uniform intensity for heating the ACF.

FIG. 28 is a diagram showing still another example of an optical system applicable to the present embodiment.
Referring to FIG. 28A, in this optical system, the light (laser beam LB) emitted from the optical fiber 41 is irradiated to the ACF 10 and the electronic component (driver IC 5 in FIG. 28) as diverging light. The holder 43a is a fiber holder. A lens for diverging the laser light emitted from the optical fiber 41 is provided in the holder 43a so that a spot having an appropriate size is formed on the irradiation surface (the contact surface between the liquid crystal display panel 1 and the ACF 10). It may be attached. In the following description, it is assumed that the lens is not attached to the holder 43a.

  In this optical system, the position of the emission end of the optical fiber 41 is preferably as close as possible to the liquid crystal display panel 1. For this reason, the backup substrate 55 is formed with a hole 55d penetrating in the vertical direction (thickness direction). The holder 43a is movable up and down along this hole. By moving the holder 43a in this way, the beam size of the laser light emitted from the optical fiber 41 can be adjusted.

  Further, in the case of alignment between the extraction electrode on the liquid crystal display panel 1 and the bump electrode of the corresponding driver IC 5, it is necessary to move the camera to the corresponding position. As shown in FIG. 28B, the camera 60 moves along the horizontal direction inside the hole 55d. On the other hand, in order to avoid interference with the camera 60, the holder 43a (and the optical fiber 41) is retracted downward when the camera 60 is moved.

FIG. 29 is a diagram illustrating the configuration of the holder 43a shown in FIG.
FIG. 29A is a top view of the holder 43a. FIG. 29B is a side view of the holder 43a. With reference to FIGS. 29A and 29B, the plurality of holders 43 a are fixed by a fixture 45. The fixture 45 is made of a transparent material such as glass. A guide illumination 46 constituted by, for example, a surface emitting LED or a lamp is attached to the lower portion of the fixture 45.

  The guide light from the guide illumination 46 passes through the fixture 45, which is a light guide, and becomes divergent light when it exits the fixture 45. In FIG. 29B, the guide light is indicated by a solid line, and the laser beam LB is indicated by a broken line. The NA (numerical aperture) of the guide illumination 46 is designed to match the NA of the optical fiber 41. Thereby, the irradiation area by the laser beam LB emitted from the optical fiber 41 can be indicated by the guide light from the guide illumination 46.

  In this configuration example, the backup substrate may be glass, quartz, or metal. When the backup substrate is made of glass or quartz, the hole 55d does not necessarily have to penetrate through in the vertical direction. On the other hand, when the backup substrate is made of metal, it is necessary to vertically penetrate the hole 55d in order to allow the light from the optical fiber to reach the ACF 10. Further, the backup substrate 55 may be replaced according to a change in the type of electronic components to be joined.

FIG. 30 is a diagram showing still another example of an optical system applicable to the present embodiment.
FIG. 30A is a cross-sectional structure diagram of the optical system along the traveling direction of the laser light. Referring to FIG. 30 (a), this optical system includes an optical fiber 41, a ferrule 44 into which the output end side of the optical fiber 41 is inserted, a fixture 45 that fixes a plurality of ferrules 44, an optical fiber, A plurality of integrators 91 for passing the laser light emitted from the fiber 41, an integrator guide 92 for installing the plurality of integrators 91 at predetermined positions, and the laser light reflected at the incident end of the integrator 91 are guided. An optical fiber 93 and a light receiving element 94 that receives light emitted from the optical fiber 93 are provided.

  By passing the light emitted from the optical fiber 41 through the integrator 91, the integrator 91 can output light having a uniform intensity distribution. Note that the way in which the light spreads changes according to the distance from the light emission position of the integrator 91 to the liquid crystal display panel 1.

  In this optical system, the integrators 91 are arranged in an array. FIG. 30B shows a state in which light from a plurality of integrators 91 arranged in an array overlaps in an irradiation region on an irradiation surface (a contact surface between the liquid crystal display panel 1 and the ACF 10). The light from the integrator 91 spreads in the region 95 and the surrounding region (indicated by a broken line frame). As a result, a plurality of rectangular light spots arranged in a mesh shape are formed on the irradiation surface, so that a continuous irradiation region can be formed and the intensity distribution in the irradiation region is substantially uniform. can do.

  As shown in FIG. 30A, a mask 59 that shields light from the integrator 91 is provided inside the backup substrate 55. With this mask 59, as shown in FIG. 30B, it is possible to irradiate only a desired region on the irradiation surface, that is, an irradiation region AR (shown by a solid line) with a laser beam.

  The light receiving element 94 receives the laser beam reflected by the incident end of the integrator 91 and outputs a signal indicating the received light intensity. This signal reflects the intensity of the laser light emitted from each optical fiber 41. Therefore, by using the optical system shown in FIG. 30, the intensity distribution of the laser light in the irradiation area AR can be arbitrarily controlled based on the signal from each light receiving element 94. For example, it is possible to make the intensity uniform throughout the irradiation area AR, or to make the intensity of a specific area stronger or weaker than other areas.

  Referring to FIG. 31, the spread of light emitted from each integrator 91 increases in the order of (a), (b), and (c). The hatched area corresponds to the area 95 shown in FIG. Here, the relationship between the spread of light and the thickness of the mask 59 is as follows. The thinner the mask 59, the smaller the spread of the light emitted from each integrator 91. On the other hand, the thicker the mask 59, the larger the spread of the light emitted from each integrator 91.

  The smaller the spread of the light emitted from each integrator 91, the larger the portion where the light overlaps, and the higher the power density. In addition, the uniformity of strength is improved. In addition, the mesh pitch is shortened. On the other hand, the greater the spread of the light emitted from each integrator 91, the smaller the portion where the light overlaps on the irradiated surface, and the lower the power density. In addition, the uniformity of intensity on the irradiated surface also deteriorates. Further, the mesh pitch becomes longer.

  FIG. 31 illustrates parameters that can change the spread of the light emitted from the integrator 91, and indicates that the larger the spread of the light emitted from each integrator 91 is, the less desirable it is. It is not a thing. The degree of spread of the light emitted from the integrator 91 is appropriately determined depending on the required power density, the size of the irradiation area, and the like.

  In the above description, ACF is shown as an example of an anisotropic conductive material that is an adhesive made of a heat-reactive resin. However, the anisotropic conductive material is not limited to ACF. For example, ACP (Anisotropic Conductive Paste) )

  In the above description, a liquid crystal display device is shown as the display device. However, the bonding apparatus and the bonding method according to the present embodiment include an electrode of an object to be bonded (display panel) and an electrode of an object to be bonded (for example, TCP, bare chip, other electronic components) via an anisotropic conductive material. Can be widely applied to display devices to which are bonded. Therefore, the display device that can be processed by the bonding device and the bonding method according to the present embodiment is not limited to the liquid crystal display device, and may be a plasma display, an organic EL (Electro Luminescence) display, a field emission display, or the like.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

It is a schematic block diagram of the liquid crystal display device which is a process target of the joining apparatus according to embodiment of this invention. It is a figure explaining the example of 1 structure of TCP2 shown in FIG. It is a figure explaining ACF. It is a block diagram of the joining apparatus 100 according to embodiment of this invention. It is a 1st figure for demonstrating the structure of the laser beam irradiation part contained in the joining apparatus 100 according to this Embodiment. It is a 2nd figure for demonstrating the structure of the laser beam irradiation part contained in the joining apparatus 100 according to this Embodiment. It is the figure seen from the X direction explaining the arrangement | positioning of the fixture 45 and the temperature detection part 64. FIG. It is a figure explaining the irradiation area | region of the laser beam on the backup board | substrate 55. FIG. It is a figure for demonstrating the structure of the beam shaping part contained in the joining apparatus 100 according to this Embodiment. 6 is a schematic diagram for explaining shaping of a laser beam in the Y direction by a backup substrate 55. FIG. 4 is a diagram for explaining a semiconductor laser used as a laser light source 32. FIG. It is a figure for demonstrating the pressurization head 25 shown in FIG. It is a block diagram for demonstrating the control system of the joining apparatus 100 according to this Embodiment. It is a flowchart for demonstrating the whole joining process which joins the liquid crystal display panel 1 and mounting components via ACF10. It is a flowchart for demonstrating a laser beam irradiation process. FIG. 3 is a diagram showing a laser light irradiation area AR when a bare chip (driver IC 5) is mounted on the liquid crystal display panel 1; It is a figure for demonstrating that the state of the heat-reactive resin in ACF changes with the temperature of the resin. It is a figure for demonstrating the problem which may arise when the irradiation area AR of a laser beam is not appropriate. It is a figure which shows typically the spatial distribution of the power of a laser beam. It is a figure explaining the relationship between the penetration depth of the light into aluminum and silicon, and the wavelength of the light. It is a figure which shows the irradiation area | region AR of the laser beam in the case of connecting the lead conductor 2b provided in TCP2 to the electrode on the liquid crystal display panel 1 via ACF. It is a figure which shows the modification of the backup board | substrate 55. FIG. It is a figure which shows the modification of the pressurization head 25 shown in FIG. It is a figure which shows an example of the optical system applicable to this Embodiment. It is a figure which shows the other example of the optical system applicable to this Embodiment. It is a figure which shows the further another example of the optical system applicable to this Embodiment. It is a figure which shows the further another example of the optical system applicable to this Embodiment. It is a figure which shows the further another example of the optical system applicable to this Embodiment. It is a figure explaining the structure of the holder 43a shown in FIG. It is a figure which shows the further another example of the optical system applicable to this Embodiment. 6 is a diagram for explaining an example of overlapping of light emitted from each of a plurality of integrators 91. FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Liquid crystal display panel, 1a Panel electrode, 2 TCP, 2a Carrier tape, 2b Lead conductor, 3 Printed circuit board, 4 Interface part, 5 Driver IC, 5a Bump electrode, 6 Flexible board, 7 Polarizing plate, 10a Binder area | region, 11 Microparticle, 11a Microparticle region, 12 Nickel plating layer, 13 Resin core, 14 Gold plating layer, 15, 16 Electrode, 20 cylinder, 21 Chip tray, 22 Cylinder moving mechanism, 23 Adsorption hole, 24 Valve, 25 Pressure head, 25a, 25b Holding member, 25c Thermally conductive material, 31 Laser device, 32 Laser light source, 32a, 32b Semiconductor laser, 33, 41, 93 Optical fiber, 34 Laser cooling device, 35 Laser controller, 35a Temperature detection circuit, 35b System Circuit, 35c, 68c Memory, 35d, 68d, 69b, 69c Interface circuit, 36 Power supply, 38 Laser light protection cover, 40 Fiber repeater, 42 Lens, 42a Aspherical lens, 42b Collimating lens, 43 Lens holder, 43a holder , 44 Ferrule, 45 Fixture, 46 Guide illumination, 47 Input connector, 48 Output connector, 51 Support member, 51a Optical system moving device, 52 Slide rail, 53 Fixed part, 55 Backup substrate, 55b, 55c Surface, 55a, 57a Inclined surface, 55d hole, 56 X direction movable light shielding member, 56a X direction movable light shielding member driving unit, 57 Y direction light shielding member, 57b plane, 58 laser light absorber, 60 camera, 62 arm, 62a arm moving device, 64 temperature Detection unit 64 f filter, 64 a temperature sensor, 64 b cylinder, 65 signal line, 66, 67 signal connector, 68 temperature calculation unit, 68 a A / D conversion circuit, 68 b, 69 a arithmetic circuit, 69 temperature control unit, 70 control device, 75 motor driver , 77 Vacuum suction unit, 80 Display device, 82 Storage device, 91 Integrator, 92 Integrator guide, 94 Light receiving element, 100 Joining device, 101, 102 Condenser lens, 103 Shutter, 104 Imaging lens, 105 Objective lens, 106 Lens, 107 Galvano mirror, 108 Rotation drive unit, AR irradiation area, EM emitter, LB laser beam.

Claims (21)

An extraction electrode composed of a plurality of first electrodes arranged on a glass substrate as an object to be joined, and is included in the object to be joined of the extraction electrode and arranged in correspondence with the arrangement of the plurality of first electrodes. A plurality of second electrodes that are electrically joined to each other with an adhesive made of a heat-reactive resin interposed therebetween,
A laser beam irradiation unit for irradiating the adhesive with a laser beam for heating the thermally reactive resin;
The laser beam irradiation unit is
A plurality of laser light sources;
A laser control unit that controls the intensity of the laser light emitted from each of the plurality of laser light sources so as to be independent of each other and to be constant or temporally change with respect to time,
By irradiating the surface of the joining object on which the plurality of second electrodes are formed with different positions with the laser light emitted from each of the plurality of laser light sources, the contour of the joining object is obtained. A bonding apparatus that irradiates the entire region determined by the laser beam with the laser beam. The laser beam irradiation unit is
The bonding apparatus according to claim 1, further comprising a beam shaping unit configured to shape a beam shape of the laser light irradiated onto the adhesive by the plurality of laser light sources. The joining object is
Including a plurality of electrodes formed on the surface of the joining object as the plurality of second electrodes,
2. The bonding apparatus according to claim 1, wherein the region of the adhesive that is irradiated with the laser light has substantially the same size as the surface of the bonding object on which the plurality of electrodes are formed.   The laser beam irradiation unit and the beam shaping unit are configured such that the laser beam power is emitted from the laser beam irradiation unit in an irradiation region that is the region irradiated with the laser beam in the adhesive. The bonding apparatus according to claim 2, wherein the laser beam is concentrated on the irradiation region so that the power is 90% or more. The laser beam irradiation unit is
A plurality of optical fibers that transmit the laser light so that the laser light emitted from each of the plurality of laser light sources travels in a direction toward the adhesive;
A plurality of lens holding members each having a plurality of lenses that convert the laser light emitted from the optical fiber into parallel light;
2. The bonding apparatus according to claim 1, wherein in each of the lens holding members, the plurality of lenses are arranged in one direction at a pitch determined so that the parallel lights overlap each other.   The plurality of lens holding members include the parallel light emitted from each of the plurality of lenses provided on one lens holding member and the plurality of lenses provided on another lens holding member different from the one lens holding member. The bonding apparatus according to claim 5, wherein the parallel light emitted from each of the lenses is arranged so as to gather in the beam shaping unit. The joining device includes:
A support member formed of a transparent material and supporting the glass substrate;
For the alignment of the plurality of second electrodes of the object to be joined to the plurality of first electrodes on the glass substrate, which are disposed between the plurality of lens holding members and the support member, A camera that photographs the plurality of first electrodes and the plurality of second electrodes via a support member and the glass substrate;
Camera movement that moves the camera to a predetermined position when the alignment is performed, and retracts the camera from a position on the optical path of the parallel light when the parallel light is emitted from each of the plurality of lenses The joining apparatus according to claim 5, further comprising a mechanism. The joining device includes:
A temperature detection unit for detecting temperatures of a plurality of locations of the irradiation region of the laser beam in the adhesive;
A temperature distribution generation unit that generates a temperature distribution of the irradiation region based on the temperatures of the plurality of locations detected by the temperature detection unit;
The bonding apparatus according to claim 5, wherein the laser control unit controls each of the plurality of laser light sources based on the temperature distribution generated by the temperature distribution generation unit. The joining device includes:
A support member formed of a transparent material and supporting the glass substrate;
A beam shaping unit for shaping the beam shape of the laser light irradiated onto the adhesive by the plurality of laser light sources;
The beam shaping unit
Including a slit disposed between the plurality of lens holding members and the support member for shaping the beam shape in a first direction along the surface of the glass substrate;
The support member is
The bonding apparatus according to claim 5, wherein the bonding apparatus has a slope that intersects a surface facing the glass substrate and is inclined with respect to a vertical direction of the facing surface.   The bonding apparatus according to claim 9, wherein an angle formed between the perpendicular to the inclined surface and the parallel light is larger than a total reflection angle of the parallel light on the inclined surface. The joining device includes:
The bonding apparatus according to claim 9, further comprising an absorber provided along the slope and capable of absorbing the laser beam.   The joining apparatus according to claim 11, wherein the slope is a rough surface. The joining device includes:
The bonding apparatus according to claim 9, further comprising an absorber provided around the support member and in a reflection direction of the laser light reflected on the slope, and capable of absorbing the laser light.   The bonding apparatus according to claim 13, wherein a surface of the support member on which the laser beam reflected on the slope is emitted from the inside of the support member is a rough surface. The joining device includes:
The bonding apparatus according to claim 9, further comprising a moving mechanism that moves the plurality of lens holding members along the second direction perpendicular to the first direction. The joining device includes:
A pressure device for applying pressure to the object to be joined from the opposite side to the adhesive;
2. The bonding apparatus according to claim 1, wherein the laser beam irradiation unit irradiates the laser beam toward the adhesive in a state where pressure is applied to the objects to be bonded by the pressure device. The pressure device is
Including a pressing member for pressing the object to be joined;
At least one through hole is formed in the pressing member,
The said joining apparatus is a joining apparatus of Claim 16 further provided with the vacuum suction part for making the said pressing target member vacuum-suck the said to-be-joined object through the said at least 1 through-hole. The pressure device is
Including a pressing portion for pressing the object to be joined;
The joining device according to claim 16, wherein a material of the pressing member is a material selected from ceramic, quartz, and glass. The laser beam irradiation unit is
By guiding the laser light from the corresponding laser light source, the intensity of the laser light is made uniform, and a plurality of elements are arranged collectively so that planar irradiation with the uniformed laser light is possible A light guide,
The bonding apparatus according to claim 1, further comprising a mask for shaping a beam shape of the laser light emitted from the plurality of light guide paths.   The bonding apparatus according to any one of claims 1 to 19, wherein the adhesive is an adhesive in which conductive particles are dispersed in the thermally reactive resin. An extraction electrode composed of a plurality of first electrodes arranged on a glass substrate as an object to be joined, and is included in the object to be joined of the extraction electrode and arranged in correspondence with the arrangement of the plurality of first electrodes. A plurality of second electrodes that are electrically joined to each other with an adhesive made of a heat-reactive resin interposed therebetween,
Pressurizing the joining objects;
Irradiating a laser beam for heating the heat-reactive resin toward the adhesive in a state where the bonding object is pressurized,
The step of irradiating the laser beam includes:
Controlling the intensity of laser light emitted by each of the plurality of laser light sources to be constant or temporally change with respect to time independently of each other;
By irradiating the surface of the joining object on which the plurality of first electrodes are formed with the laser light emitted from each of the plurality of laser light sources at different positions, the contour of the joining object Irradiating the entire region determined by the laser beam with the laser beam.

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