JP2574704B2 - Bonding equipment - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bonding apparatus, and more particularly, to anisotropically forming a semi-transparent electrode on a glass substrate such as a liquid crystal panel and peripheral components such as a driver component for driving the liquid crystal. The present invention relates to a bonding apparatus for bonding via a conductive film.

[Background Art] Conventionally, this type of bonding connection has been
Unlike the case of bonding a semiconductor integrated circuit such as a flat package by soldering, a pressing load of several tens of kg / cm ² and overheating of several hundred degrees are required. In this bonding connection, as shown in FIG. 4, a load is applied to a part to be bonded by a superheated bonding tool 30 (hereinafter, referred to as a tool), and the superheated connection is performed by the amount of heat of the tool itself and the amount of heat transmitted to the tool. . That is, the bonding apparatus shown in FIG. 4 includes a tool 30 having a substantially U-shaped cross section for pressurizing a part to be bonded by an elevating mechanism (not shown) and performing overheating connection, and a pair of tools 30 for fixing and holding the tool 30 with tool fixing screws 31. Of the electrodes 32a and 32b, an insulating member 33 for supporting the electrodes 32a and 32b, and a pair of cables 34a and 34b for supplying a current to the electrodes 32a and 32b.

In the apparatus having the above-described configuration, a bonding component 5 having an electrode formed on the lower surface serving as a component to be bonded and a pattern electrode of the glass substrate 1 are connected to each other by pressurized heating through an anisotropic conductive film 3. This overheating connection is made with the cables 34a, 34
A current flows from b through the electrodes 32a and 32b to the tool 30, and the tool 30 is overheated and pressed by Joule heat generated in the tool resistance portion.

The bonding connection using the anisotropic conductive film as described above will be described in detail with reference to FIGS.

FIG. 5 is a view showing the structure of a simple matrix panel of a liquid crystal display. A plurality of stripe-like ITOs (indium-tin-ox) are provided on the facing surfaces of the upper and lower glass substrates 36 and 37.
ide) The electrodes 36a and 37a are formed. These electrodes 36a, 37a
Is a translucent electrode, in which a data electrode 36a is formed on an upper substrate and a scanning electrode 37a is formed on a lower substrate as shown.
Further, between the upper and lower substrates 36 and 37, a liquid crystal filling port 40 for injecting liquid crystal and a seal portion 41 for sealing the liquid crystal are provided.

Mounting area excluding terminal area with liquid crystal filling port 40 in the figure
The connection with the above-mentioned ITO terminal of 39 is a tape or substrate (hereinafter referred to as a tape) formed of a polyimide film or the like.
Is pressurized through the anisotropic conductive film and the electrode formed in the above step, and overheated.

This anisotropic conductive film is applied to a tape 4 made of a polyimide film or the like as shown in FIG.
The electrodes 5 formed in a stripe shape corresponding to 36a and 37a and the electrodes formed on the glass substrate 1 are overheat-pressed through the anisotropic conductive film 3. The film 3 is conductive in the thickness direction of the pressurized portion but is insulated in the horizontal direction, so that it can be easily electrically connected.

[Problems to be Solved by the Invention] However, the bonding connection performed through the anisotropic conductive film 3 by the conventional bonding apparatus has the following disadvantages.

That is, first, the tape 4 formed of a polyimide film or the like on which the electrodes 5 as the joining parts are formed is bonded by heat and pressurized as in the related art. If overheated, it tends to shrink and the pitch between the electrodes may shift. In addition, since this bonding bonds the mounting area 39 at a time as shown in FIG. 5, there is a disadvantage that if one electrode is shifted, the other adjacent electrodes are relatively differently shifted. If the method of directly heating the electrodes and the anisotropic conductive film 3 without using the tape 4 and applying the method of heating and bonding is used, there is a problem that the tool surface is stained. Therefore, the tape 4 formed of a polyimide film or the like is generally used. It is used regularly.

Second, the conventional method has a disadvantage in that the heat distribution on the tool bonding surface varies, and the pitch between the electrodes is relatively shifted, so that accurate bonding cannot be performed.

Third, there is a drawback that the expansion of the tool 30 also varies due to the variation in the heat distribution, and the flatness of the tool bonding surface may not be maintained.

Fourthly, the overheating of the tool 30 also affects the peripheral panels and the like on which the ITO electrodes are formed, so that the parallelism of the tool 30 to the object to be bonded cannot be maintained.

Fifth, in the conventional apparatus, since overheating starts before the object to be bonded is completely pressed down, there is a drawback that a shift due to heat occurs. Conversely, if the object to be bonded is held down before overheating, there is a drawback that the thermal efficiency deteriorates and the rise of heat is slow.

Sixth, there is a disadvantage that the processing accuracy of the tool bonding surface is severe and processing is difficult.

Seventh, there is a disadvantage that the tool 30 must be changed when switching between different types of shapes.

Eighth, there is a disadvantage that the bonding surface of the tool 30 is deformed, so that it is necessary to periodically polish the tool.

The present invention has been made in view of the above-mentioned disadvantages of the prior art,
Accuracy without applying long-time heating to the parts to be bonded, even in bonding connection where electrodes formed on a tape surface such as a polyimide film and electrodes formed on a glass substrate are connected via an anisotropic conductive film. It is an object of the present invention to provide a bonding apparatus capable of performing good bonding connection.

[Means for Solving the Problems] According to the present invention, there is provided a substrate having a plurality of electrodes formed in stripes at predetermined intervals, and a plurality of electrodes arranged in stripes corresponding to each of the electrodes to have flexibility. For a band-shaped medium, in a bonding apparatus for connecting the electrode of the substrate and the electrode of the medium via an anisotropic conductive film, the electrode of the medium and the electrode formed on the substrate, After positioning, the medium is subjected to ultrasonic longitudinal vibration in the thickness direction of the medium by ultrasonic wave generating means to electrically connect the electrode of the medium and the electrode on the substrate via the anisotropic conductive film. It is configured to be connected.

Example Next, an example of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a front view of a bonding apparatus used in this embodiment, FIG. 2 is a side view of FIG. 1, and FIG.
FIG. 2 is a partially enlarged view of a bonding head and a part to be bonded incorporated in the apparatus shown in FIG. Note that components having the same configuration and function as those of the related art are described using the same reference numerals.

In the figure, a transparent ITO electrode 36a, 37a of a liquid crystal display is formed on a glass substrate 1, and this glass substrate 1 is placed on a glass substrate receiving table 2 provided in the main body of the apparatus by means of vacuum suction or the like (not shown). )). The anisotropic conductive film 3 is supplied by attaching an electrode formed on a flexible strip-shaped tape 4 usually formed of a polyimide film or the like. This electrode is attached to the tape 4 or formed integrally. The tape 4 on which the electrodes are formed is configured to be able to be sucked by a suction arm 6 arranged behind the glass substrate receiving table 2 as shown in FIG. The suction arm 6 is provided with a tape XY axis 7 provided on the apparatus main body,
The movement in the horizontal plane (XY direction), the rotation in the rotation direction (θ direction), and the movement in the vertical direction (Z axis direction) are performed by the tape θ axis 8 and the tape Z axis 9 placed on the tape XY axis 7. The suction arm 6 sucks the tape 4 at a predetermined position and can stop at the predetermined position for position detection.

Next, the mechanism of the bonding head for pressing and bonding the tape 4 will be described.

In the figure, a head XY table 11 which is movable in the X and Y directions is provided on a side opposite to the upper surface of a glass substrate receiving table 2 on a frame 10 fixed on the apparatus main body. The head XY table 11 is attached with a camera 12 in front of FIG.
Is installed. This camera 12 has a head XY table 11
The position of the glass substrate 1 on the glass substrate receiving table 2 and the tape 4 is detected by the movement of the tape substrate 4, and the position of the tape 4 is corrected. A Z-axis 15 is mounted on the lower part of the head XY table 11, and the movable part 15a is movable by the Z-axis 15 in the Z-axis direction.
Is provided. The movable portion 15a supports the head θ-axis 15b. The head XY is attached to the upper end shaft 15c of the head θ-axis 15b.
A rotatable roller 13a is provided at the tip of a pressing arm 13 swingably supported on a frame shaft of a frame 11a supported by the table 11 so as to be capable of coming and going. In addition, Z axis 15
A pressure cylinder 14 for urging the other end of the pressure arm 13 is provided on the side opposite to the head θ-axis 15b. When the movable portion 15a and the head θ-axis 15b move in the direction of the arrow, the pressing arm 13 is also configured to operate following the pressing arm 13.
The pressure required for the pressurizing arm 13 to follow when the 15 is driven is supplied. Movable part 15a of Z axis 15
When the bonding tool 16 (hereinafter referred to as a tool) comes into contact with the tape 4 by lowering, the bonding pressure is supplied to the pressing cylinder 14. At this time, when the bonding pressure is small, the bonding pressure is always applied by an adjustment mechanism (not shown). This tool
The 16 flange portion is supported and fixed to the head θ-axis 15b, and includes a horn 16a and a vibrator 16b. This tool 16
The horn 16a is configured so that the vibrator 16b is excited by an oscillator (not shown) to generate ultrasonic vibrations and amplified and transmitted by the horn 16a. The tool 16 is configured so that bonding connection can be performed for the length of the bonding portion of the object to be bonded (for the bonding range), and by applying ultrasonic vibration to the bonding portion, the part to be bonded is overheated and connected. You. The resonance frequency and the like of the ultrasonic vibration applied to the tool 16 are configured to be adjusted and controlled on the oscillator main body side, and can be set by selecting optimal conditions as appropriate.

The operation of the device having the above configuration will be described.

First, the head XY table 11 is moved, and the camera 12 captures images of the positions of the glass substrate 1 and the tape 4. On the tape 4 and the glass substrate 1 which are imaged by the camera 12, marks for position detection are formed in advance on the camera side (however, if a mark cannot be made on the camera side of the tape, the camera is moved to the tape side). Since the mark is detected and the suction arm 6 sucks the tape 4, the tape 4 and the electrode on the glass substrate 1 coincide with each other by the tape XY axis 7 and the tape θ axis 8. The position correction (XY direction and θ rotation direction) is performed as described above, and the tape Z-axis 9 moves to the position as shown in FIG. next,
When the drive shaft of the Z-axis 15 moves down and the tip of the horn 16a of the tool 16 comes into contact with the tape 4, the bonding pressure is supplied by the action of the pressure cylinder 14. In this bonding pressurization, the urging force is applied by the pressurizing cylinder 14 so that the pressurizing arm 13 can follow the Z axis drive shaft around the frame axis of the frame 11a. It is given by operating. Ultrasonic vibration is applied to the tool 16 in this pressurized state, and bonding connection by ultrasonic vibration is performed from the upper surface of the tape 4 via the anisotropic conductive film.

After the bonding connection is made, the process returns to the original state by following the reverse process.

In the apparatus according to the present embodiment, the superheat necessary for bonding the glass substrate 1 and the tape 4 via the anisotropic conductive film is caused by ultrasonic vibration, and the pressurization is performed by the ultrasonic vibration and the pressure arm 13 or the like. Added to the part to be bonded by means.

Although the ultrasonic vibration applied to the tool 16 in the present embodiment has been described as an example of the longitudinal vibration in the thickness direction of the tape 4, it may be configured to connect the parts to be bonded by the lateral vibration.

[Effects of the Invention] As described above, the present invention has the following effects.

That is, first, according to the present invention, the parts to be bonded are overheated by the ultrasonic vibration, so that there is no variation in the heat distribution, and accurate bonding is performed.

Secondly, according to the present invention, only the portion to which the ultrasonic vibration is applied is locally heated in a short time, so that the influence on the surroundings is small.

Third, according to the present invention, since the object to be bonded is heated after being completely positioned and pressed, there is no deviation due to the heat before pressing.

Fourth, according to the present invention, since ultrasonic vibration is used, heat rises quickly and can be overheated in a short time, so that there is no adverse effect on the tape-shaped medium on which the electrodes are formed, and the pitch between the electrodes is shifted. Etc. do not occur.

Further, since the ultrasonic vibration to be applied is a longitudinal vibration in the thickness direction of the medium, distortion in the surface direction of the medium due to the vibration itself, and therefore, displacement of the electrode is prevented.

Fifth, according to the present invention, the state in which the flatness and the parallelism are adjusted by performing adjustment at room temperature or polishing outside the apparatus to prevent overheating of the tool itself by using ultrasonic vibration during bonding is performed. Can be easily reproduced and maintained.

[Brief description of the drawings]

FIG. 1 is a front view of a bonding apparatus used in the present invention, and FIG. 2 is a side view of FIG.
FIG. 3 is a partially enlarged view of a bonding head and a part to be bonded incorporated in the apparatus of FIG. 1, FIG. 4 is a view schematically showing the structure of a conventional bonding apparatus, and FIG. 5 is a simple matrix of a liquid crystal display. FIG. 6 is a view showing the structure of the panel, and FIG. 6 is a view for explaining the connection principle of the anisotropic conductive film. DESCRIPTION OF SYMBOLS 1 ... Glass substrate, 2 ... Glass substrate support, 3 ... Anisotropic conductive film, 4 ... Tape, 5 ... Joined parts, 6 ... Suction arm, 7 ... Tape XY axis, 8 ... Tape θ axis, 9 ...
Tape Z axis, 10 Frame, 11 Head XY table, 12 Camera, 13 Pressure arm, 14 Pressure cylinder, 15 Z axis, 16 Bonding tool, 16a
... horn, 16b ... vibrator.

Claims (1)

(57) [Claims] 1. A substrate in which a plurality of electrodes are formed in a stripe at predetermined intervals, and a medium in which a plurality of electrodes are arranged in a stripe so as to correspond to each of the electrodes, and a flexible strip is formed. A bonding apparatus that performs connection between the electrode of the substrate and the electrode of the medium via an anisotropic conductive film, and after positioning the electrode of the medium and the electrode formed on the substrate, Ultrasonic longitudinal vibration in the thickness direction of the medium is applied to the medium by ultrasonic wave generating means to electrically connect an electrode of the medium and an electrode on the substrate via an anisotropic conductive film. A bonding apparatus.