JP5045177B2 - Mounting method of electronic parts - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of mounting an electronic component by which an ACF is used electrically to connect an electronic part to a circuit board surely and in high reliability and the electronic part can be also mounted easily thereto. <P>SOLUTION: The ACF tape 2 is conveyed in horizontal direction while a changing station is supported by a pair of supporting rollers 13a and 13b. A heat crimping tool with a driver chip 8 sucked on the end face of a suction head 411 is lowered to the ACF tape 2, hitting the conduction junction surface 81 of the driver chip 8 to the ACF layer 22 of the ACF tape for heating within a range between 45&deg;C and 55&deg;C and pressing within 40-60 kgf/cm<SP>2</SP>for about 4 to 6 seconds, thereby changing an ACF to the conduction junction surface 81 so as to punch out an ACF with almost the same area thereon. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

  The present invention relates to a method for mounting an electronic component using an anisotropic conductive adhesive.

  Conventionally, an anisotropic conductive adhesive film (hereinafter referred to as ACF: Anisotropic Conductive Film) excellent in workability has been used as a conductive bonding material when a semiconductor element such as an IC chip is mounted on an electronic circuit board. This ACF is obtained by dispersing and mixing conductive particles having an average particle diameter of about 5 μm in a thermosetting resin as a binder, and molding the film into a film.

When mounting a semiconductor element on an electronic circuit board using this ACF, normally, as shown in Patent Document 1, in view of misalignment when arranged on the electronic circuit board, In other methods, the ACF having a large area is disposed at the mounting position of the electronic circuit board, and the semiconductor element is mounted on the ACF.
Japanese Patent Laid-Open No. 11-3910

  In this method, when a semiconductor element is placed on an ACF having a larger area than the conductive bonding surface and the semiconductor element is pressed by a thermocompression bonding tool, the ACF protruding from the conductive bonding surface is pressed by the pressing surface of the thermocompression bonding tool. As a result, the parallelism between the pressing surface and the surface of the semiconductor element is disturbed, and as a result, defects such as poor conduction occur in the thermocompression bonding of the semiconductor element.

  Further, the protruding ACF is in an uncured state because it is not sufficiently heated, and the uncured ACF is likely to absorb moisture over time, causing corrosion on the wiring on the electronic circuit board.

  An object of the present invention is to provide an electronic component mounting method capable of reliably and electrically connecting an electronic component to a circuit board using an ACF.

The electronic component mounting method according to claim 1 of the present invention is a conductive bonding tape in which an anisotropic conductive adhesive formed by dispersing and mixing conductive particles in a thermosetting resin is coated on a base film. A step of transporting the electronic component along a first path, a step of transporting the electronic component along a second path parallel to the first path, and a device to be mounted in parallel with the second path. And it is conveyed along the second path by the step of conveying along the third path provided on the side opposite to the first path with the second path as a reference, and the thermocompression bonding apparatus. the electronic component was the pressure contact at a predetermined pressure to the anisotropic conductive adhesive of predetermined while heating to a temperature above its conduction bonding surface a first said conductive bonding tape which is transported along the path of, pressure was thereby was said anisotropic conductive adhesive areas are transferred to the conductive bonding surface And extent, by the thermocompression bonding device, said anisotropic conductive adhesive agent electronic component is transferred to the conductive bonding surface, it is moved to the mounting position of the third mounting target device that has been conveyed along the path of it is characterized in that chromatic and a step of placing the electronic component on the mounting position.

The electronic component mounting method according to claim 2 is the electronic component mounting method according to claim 1, wherein the pressure for pressing the electronic component in the step of transferring the anisotropic conductive adhesive to the conductive joint surface is 40. The temperature is set within a range of ˜60 kgf / cm ² , and the temperature is set within a range of 50 ° C. to 60 ° C., respectively.
The electronic component mounting method according to claim 3 is the electronic component mounting method according to claim 1 or 2, wherein the thermocompression bonding device is provided to be movable in a direction perpendicular to the first path, and It is possible to reciprocate from one route to the third route.

  According to the electronic component mounting method of the present invention, the electronic component can be easily and reliably conductively bonded to the circuit board with high reliability.

  FIG. 1 is a plan view showing a driver chip mounting process as an embodiment of the present invention in a liquid crystal display module manufacturing method, and FIGS. 2 (a) to 2 (c) show operations in the main process for each stage. Each stage perspective view, FIGS. 3 (a) and 3 (b) are further explanatory diagrams showing each stage by further enlarging the operation of the principal part in the principal part process, and FIGS. 4 (a) to 4 (c) are respectively. It is a top view which shows each work station in the above-mentioned installation process.

  In FIG. 1, reference numeral 1 denotes a tape transport device that causes an ACF tape 2 to travel along a predetermined path. The tape transport device 1 includes a supply reel 11, a take-up reel 12, a pair of support rollers 13a and 13b, and the like. The take-up reel 12 is driven and rotated by a drive device (not shown), and the supply reel 11 rotates following the rotation. The ACF tape 1 is fed out and taken up by the take-up reel 12 through a pair of support rollers 13a and 13b. In this case, the rotational speed of the take-up reel 12 is driven and controlled so that the ACF tape 2 travels at a constant speed. The pair of support rollers 13a and 13b are provided to allow the ACF tape 2 to run horizontally at a constant height without slack.

  As shown in FIGS. 3A and 3B, the ACF tape 2 has a surface layer of anisotropic conductive adhesive (hereinafter referred to as ACF) on the surface of a Teflon (registered trademark) base film 21 that also serves as a separator. 22) is applied. This anisotropic conductive adhesive is obtained by dispersing and mixing, as conductive particles, an acrylic resin filler subjected to gold plating with an average particle size of about 5 μm in an epoxy resin as a binder.

  An ACF transfer station is provided at an intermediate position between the pair of support rollers 13a and 13b. In this transfer station, as shown in FIG. 2 (a), a support base 3 is installed. As shown in FIG. 3 (a), between the surface of the support base 3 and the ACF tape 2 which is supported and travels between the support rollers 13a and 13b with a constant tension, the tape thickness t is approximately equal. A gap D of about three times is secured.

  The thermocompression bonding apparatus 4 according to this embodiment includes a thermocompression bonding tool 41, an actuator 42 that moves the thermocompression bonding tool 41 up and down, and a holding block 43 that holds the thermocompression bonding tool 41 via the actuator 42. The thermocompression bonding tool 41 includes a suction head 411 and a tool main body 412, and includes a vacuum suction mechanism and a heater (not shown).

  As shown in FIG. 1, the above-described thermocompression bonding device 4 is installed on a carriage (not shown) so as to be able to reciprocate on a rail 5 extending in a direction perpendicular to the travel path of the ACF tape 2. The thermocompression bonding device 4 is pivotally supported by a shaft 44 standing on the carriage.

  A conveyor belt 7 of the liquid crystal display panel 6 is extended and installed in parallel with the travel path of the ACF tape 2, and a conveyor belt 9 of the driver chip 8 is extended and installed between them. Both of these conveyor belts 7 and 9 travel and move in the same direction as the traveling direction of the ACF tape 2, and their operations are controlled by a drive control device (not shown) according to a predetermined drive program.

  The transport belt 7 of the liquid crystal display panel 6 intersects with the lower end portion of the rail 5 opposite to the transfer station side below, and the front end of the rail 5 is the mounting station for the driver chip 8. The liquid crystal display panel 6 supplied to the mounting station for mounting the driver chip 8 is placed at a predetermined position on the transport belt 7 at regular intervals and intermittently transported at predetermined intervals.

  The conveyor belt 9 of the driver chip 8 travels below the rail 5, and the intersection thereof becomes a suction station for the driver chip 8. The driver chips 8 supplied to the suction station are also placed at predetermined intervals on the conveyor belt 9 and are intermittently conveyed at predetermined intervals.

  Next, a chip mounting method implemented in the driver chip mounting step configured as described above will be described.

  First, as shown in FIG. 4A, the thermocompression bonding apparatus 4 is stopped in a state where the tip surface of the adsorption head 411 of the thermocompression bonding tool 41 is located above the chip adsorption station, and the thermocompression bonding tool 41 is lowered by a predetermined stroke. Then, after the driver chip 8 waiting at the suction station is sucked to the front end surface of the head, the thermocompression bonding tool 41 is raised to the original position and stopped.

  Next, after rotating the thermocompression bonding device 4 by 90 degrees counterclockwise, it travels on the rail 5 toward the transfer station, and the tip surface of the suction head 411 is transferred as shown in FIG. Stop at the top of the station.

Thereafter, the thermocompression bonding tool 41 is lowered, and the conductive bonding surface 81 of the driver chip 8 adsorbed on the tip surface of the adsorption head 411 is brought into contact with the ACF layer 22 of the ACF tape 2 as shown in FIG. Further, the back surface of the base film 21 of the ACF tape 2 is brought into close contact with the support base 3 as shown in FIG. Then, the driver chip 8 and the ACF tape 2 superimposed on the front end surface of the suction head 411 are pressed against the support 3 at a predetermined pressure for about 1 to 2 seconds. Preferably the pressing force in the range of about 40~60kgf / cm ² at this time, among them, a pressure within the range of 48~52kgf / cm ² is more preferable.

  Further, the driver chip 8 is heated to a predetermined temperature by a heater built in the thermocompression bonding apparatus 4 until it is sucked by the suction head 411 and moved to the transfer station. The heating temperature of the driver chip 8 is preferably within a range of 40 to 60 ° C, and more preferably within a range of 45 to 55 ° C.

  When the driver chip 8 heated to the above-described temperature is pressed against the ACF layer 22 by the pressure described above for about 1 to 2 seconds, the ACF layer 22 in the area contacting the conductive bonding surface 81 of the driver chip 8 is And is softened by being heated to substantially the same temperature as that, and adheres to the conductive bonding surface 81 of the driver chip 8 and forms a rectangular groove in which the edge 82 of the conductive bonding surface 81 bites. This is because the ACF tape 2 stretched between the pair of support rollers 13a and 13b is bent at the contact portion of the edge 82 when the chip pressing portion of the ACF tape 2 is pushed down toward the support base 3 by the gap D. This is because the edge 82 penetrates deeper into the ACF layer 22.

  Next, the thermocompression bonding tool 41 is raised from the pressed state shown in FIGS. 2 (b) and 3 (b) to the original position before being lowered as shown in FIG. 2 (c). At this time, the ACF layer 22 in the area where the conductive bonding surface 81 of the driver chip 8 is in pressure contact is moderately softened and adhered to the conductive bonding surface 81, and the chip pressure contact area portion is a rectangular groove formed by the biting of the edge 81. And the base film 21 is a film made of (registered trademark) Teflon (registered trademark) having excellent releasability. Therefore, when the driver chip 8 rises together with the suction head 411, the conductive bonding surface thereof The ACF layer 22 in the area divided by the rectangular groove attached to 81 is separated from the other parts and peeled off from the base film 21, and rises while being attached to the conductive bonding surface 81 of the driver chip 8. That is, the ACF layer 22 in the area where the conductive bonding surface 81 of the driver chip 8 is pressed is transferred from the base film 21 to the chip bonding surface 81 as the ACF piece 221.

  Next, the thermocompression bonding apparatus 4 is rotated 180 degrees from the state where the transfer of the ACF layer 22 to the driver chip 8 shown in FIG. 2C is completed, and then the driver chip 8 to which the ACF layer 22 is transferred and attached is adsorbed. The rail 5 is moved to the placement station side as it is, and stopped at the placement station corresponding position shown in FIG. Until this stage, the heating of the driver chip 8 is continued, and the temperature is maintained at a suitable temperature within the range of 45 to 55 ° C. described above.

  Thereafter, the thermocompression bonding tool 41 is lowered, and the driver chip 8 is placed at the chip mounting position of the liquid crystal display panel 6 waiting at the mounting station. At this time, based on an image recognition mechanism (not shown) so that the driver chip 8 is accurately placed at a predetermined position on the wiring circuit formed on the portion of the one glass substrate 61 protruding from the other glass substrate 62. The thermocompression bonding tool 41 is lowered while driving the actuator 44 to perform alignment. Then, the ACF layer 22 transferred to the driver chip 8 and heated to about 45 to 55 ° C. is brought into contact with a predetermined position of the glass substrate 61 and pressed with substantially the same pressure as that at the time of transfer, and then the adsorption is released. The thermocompression bonding tool 41 is raised to the original position. As a result, the driver chip 8 is accurately placed on the mounting position of the liquid crystal display panel 6 via the transition ACF layer 22 in a temporarily pressed state.

  Next, the thermocompression bonding apparatus 4 that has finished mounting the driver chip 8 is rotated 90 degrees counterclockwise, travels on the rail 5, and stops at a position corresponding to the suction station of the original driver chip 8. . Thereafter, the driver chip placement work on the next liquid crystal display panel is started.

The liquid crystal display panel 6 on which the driver chip 8 is mounted is transported to a downstream thermocompression bonding process (not shown) by a transport belt 7 that is intermittently driven. The ACF layer 22 is heated to a high temperature of about 180 to 190 ° C. via the driver chip 8 by a thermocompression tool different from 41, and is cured by pressing for 5 to 8 seconds at a pressure of 550 to 650 kgf / cm ² , The mounting of the driver chip 8 is completed.

  As described above, in the driver chip mounting process of the present embodiment, after the ACF layer 22 is transferred from the continuously fed ACF tape 2 to the conductive bonding surface 81 of the driver chip 8 by the die-cutting method, the driver Since the chip 8 is placed on the liquid crystal display panel 6 (temporary pressure bonding), when the ACF piece 221 transferred during the main pressure bonding in the heat pressure bonding process is heat pressure bonded under the above-described high temperature and high pressure conditions, the driver chip 8 is electrically connected. The amount of ACF that protrudes from the joint surface 81 can be minimized. As a result, the ACF that sticks out to the pressing surface of the thermocompression bonding tool during the main press bonding adheres, and the driver chip 8 cannot be pressed uniformly, resulting in poor conduction, or the uncured ACF that sticks out. Problems such as corrosion of wiring due to moisture absorption are eliminated.

In addition, by simply reciprocating the thermocompression bonding device 4 on the rail 5, three stages of mounting work including adsorption of the driver chip 8, transfer of the ACF, and placement of the driver chip 8 with ACF on the liquid crystal display panel 6 are performed. Therefore, the driver chip 8 can be appropriately mounted on the liquid crystal display panel 6 with less man-hours.

In addition, this invention is not limited to said embodiment.
For example, in the above embodiment, the ACF is transferred to the driver chip 8, and the thermocompression bonding device 4 is moved to the mounting station corresponding position and the driver chip 8 is mounted on the liquid crystal display panel 6. After the transfer, the driver chip is temporarily stocked on a pallet, and the pallet is moved to the driver chip mounting (main pressing) process, and the driver chip may be mounted on the liquid crystal display panel by another thermo-compression bonding apparatus. .

  Further, when the thermocompression bonding apparatus 4 is moved to the mounting station corresponding position with the ACF transferred to the driver chip 8, the ACF is continuously cured by the same thermocompression bonding apparatus after the driver chip 8 is mounted. You may implement the this crimping | compression-bonding process.

  In addition, the mounting method of the electronic component of the present invention is not limited to the step of mounting the driver chip on the liquid crystal display panel, and the mounting step of other electronic components on a device other than the liquid crystal display panel is a process using ACF. Needless to say, the present invention can be widely applied.

It is a top view which shows the mounting process of the driver chip to the liquid crystal display panel which is one Embodiment of this invention. (A)-(c) is a partial expansion perspective view for every step which shows ACF transfer operation | movement in the said mounting process in steps, respectively. (A), (b) is explanatory drawing according to each step explaining the transfer effect | action of ACF in the said ACF transfer operation | movement in detail, respectively. (A)-(c) is the top view which showed each work station in the above-mentioned installation process.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Tape conveyance apparatus 11 Feeding reel 12 Take-up reels 13a and 13b Support roller 2 ACF tape 21 Base film 22 ACF layer 3 Support base 4 Thermocompression bonding apparatus 41 Thermocompression bonding tool 411 Adsorption head 42 Actuator 43 Holding block 5 Rail 6 Liquid crystal display panel 7 Conveyor belt (for panel)
8 Driver chip 81 Conductive joint surface 82 Edge 9 Conveying belt (for chip)

Claims (3)

A step of transporting along a first path a conductive bonding tape having an anisotropic conductive adhesive formed by dispersing and mixing conductive particles in a thermosetting resin on a base film;
Transporting electronic components along a second path parallel to the first path;
Transporting the mounting target device along a third path provided on a side parallel to the second path and facing the first path with the second path as a reference;
By thermocompression bonding device, the said second said conductive bonding tape the conductive bonding surfaces while the conveyed the electronic component is heated to a predetermined temperature along the path is conveyed along the first path a step is pressed against a predetermined pressure to the anisotropic conductive adhesive, to transfer the anisotropic conductive adhesive of the pressure contact with the area to the conductive bonding surface,
The electronic component in which the anisotropic conductive adhesive is transferred to the conductive bonding surface by the thermocompression bonding apparatus is moved to the mounting position of the mounting target device transported along the third path. Placing the device at the mounting position;
An electronic component mounting method characterized by comprising: In the step of transferring the anisotropic conductive adhesive to the conductive joint surface, the pressure for pressing the electronic component is set in the range of 40-60 kgf / cm ² , and the temperature is set in the range of 50-60 ° C. The electronic component mounting method according to claim 1, wherein: The thermocompression bonding apparatus is provided so as to be movable in a direction perpendicular to the first path, and is reciprocally movable from the first path to the third path. The electronic component mounting method described.

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