JP3275742B2 - Chip bonding method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chip bonding method for bonding a chip on a transparent electrode on a transparent substrate.

[0002]

2. Description of the Related Art A display panel such as a liquid crystal panel, which is frequently used as a display of an electronic device, includes a driver chip mounted on a transparent electrode (generally called ITO) formed on a surface of a transparent substrate such as a glass plate. Assembled by bonding.

FIG. 8 is a side view of a conventional chip bonding apparatus, and FIG. 9 is an image view of a camera of the chip bonding apparatus. In FIG. 8, reference numeral 1 denotes a display panel, on which a transparent electrode (not shown) is formed on the upper edge, and an ACF (anisotropic conductive tape) 2 is provided on the transparent electrode.
Is affixed. Reference numeral 3 denotes a transparent stage made of a glass plate, and reference numeral 4 denotes a supporting table. A camera 5 is provided below the transparent stage 3. Reference numeral 6 denotes a lens barrel extending upward from the camera 5, and reference numeral 7 denotes a light source unit.

A mounting head 8 is provided above the transparent stage 3. The mounting head 8 is held by a vertical guide rail 10 via a slider 9 so as to be vertically movable.
Reference numeral 11 denotes a support bracket for the guide rail 10. A nozzle 12 is provided below the mounting head 8, and a chip 13 such as a flip chip is held at the lower end of the nozzle 12 by vacuum suction.

[0005] This conventional chip bonding apparatus has the above-described configuration, and its operation will be described below. First, the mounting head 8 is moved up and down to align the chip 13 vacuum-adsorbed to the nozzle 12 with the focal position of the camera 5, and the image of the chip 13 is captured to recognize the position of the chip 13. This recognition is generally performed by capturing an image of a characteristic portion of the chip 13, such as a bump or a circuit pattern on the lower surface of the chip 13. Data such as a recognition result is registered in a memory (not shown) of the control unit.

[0008] Next, as shown by a chain line in FIG. 8, the edge of the display panel 1 is moved above the camera 5, and a feature such as a recognition mark formed on the edge is observed by the camera 5. , The position of the display panel 1 is obtained. FIG.
Indicates an image of the recognition mark 14 captured in the field of view of the camera 5. The position data of the recognition mark 14 is also registered in the memory. Generally, the recognition mark 14 is formed in the vicinity of the transparent electrode with the same transparent material as the transparent electrode.

Next, a relative displacement between the chip 13 and the display panel 1 is obtained based on the recognition result described above. Next, the position shift is corrected by moving the display panel 1 in the horizontal direction relatively to the chip 13. After the displacement is corrected, the mounting head 8 is lowered to land the chip 13 on the ACF 2, and the chip 13 is bonded on the transparent electrode. Generally, the mounting head 8 has a built-in heater. The chip 13 is heated on the heater and then bonded to the transparent electrode.

[0008]

As described above, the position of the display panel 1 is recognized by observing the recognition mark 14 formed on the display panel 1 and obtaining the image data shown in FIG. Since the display panel 1 is a transparent substrate such as a glass plate, the light emitted from the light source unit 7 passes through the display panel 1 and is reflected by the lower surface of the chip 13 located above the display panel 1. Therefore, the screen flickers brightly and the recognition mark 14 cannot be recognized with a clear contrast from its background,
It was difficult to obtain high recognition accuracy.

As described above, if the recognition accuracy of the recognition mark 14 is low, the relative displacement between the display panel 1 and the chip 13 cannot be accurately obtained, and the bonding position accuracy of the chip 13 will be reduced. There was a problem.

It is an object of the present invention to provide a chip bonding method capable of accurately performing position recognition of a transparent substrate such as a display panel and bonding a chip with high positional accuracy.

[0011]

SUMMARY OF THE INVENTION A chip bonding method according to the present invention is a chip bonding method for bonding a chip on a transparent electrode of a transparent substrate, wherein the chip held at a lower end of a nozzle of a mounting head is mounted. A step of observing the position of the chip by observing with a lower camera, and positioning the transparent electrode of the transparent substrate above the camera and a background plate above the transparent electrode, and from a light source below toward the transparent substrate. A step of recognizing the position of the transparent substrate by observing the features of the transparent substrate with a camera while irradiating the illumination light, and correcting the relative displacement between the chip and the transparent substrate according to the result of the position recognition of the chip and the transparent substrate And bonding the chip onto the transparent electrode by lowering the nozzle of the mounting head.

[0012]

According to the present invention having the above-described structure, the position of the transparent substrate can be accurately obtained by observing the characteristic portion of the transparent substrate with a clear contrast from the background. Based on this observation result, the displacement between the chip and the transparent substrate can be accurately corrected, and the chip can be bonded on the transparent electrode of the transparent substrate with high positional accuracy.

An embodiment of the present invention will be described below with reference to the drawings. 1 and 2 are side views of a chip bonding apparatus according to an embodiment of the present invention, FIG. 3 is a side view of an optical system of the chip bonding apparatus, and FIG. 4 is an image of a camera of the chip bonding apparatus. FIGS. 5, 5 and 6 are side views of the bonding apparatus of the same chip, and FIG. 7 is a plan view of a background plate of the bonding apparatus of the same chip and its rotating means. The same elements as those in the conventional example shown in FIGS.

In FIG. 1, a display panel 1 as a transparent substrate is placed on a movable table 20. The movable table 20 is configured by stacking an X table 21, a Y table 22, a Z table 23, and a θ table (horizontal rotation table) 24, and the display panel 1 is mounted on the θ table 24. Therefore, when the movable table 20 operates, the display panel 1 moves in the X, Y, Z, and θ directions, and its position is adjusted.

The mounting head 8 is mounted on the rod 2 of the cylinder 25.
The mounting head 8 moves up and down along the guide rail 10 when the rod 26 protrudes and retracts.

A support table 4 for supporting the transparent stage 3
Is provided with a rotary actuator 30. The rotary shaft 31 of the rotary actuator 30 includes:
The background plate 33 is mounted via the arm 32 (FIG. 7).
See also). The background plate 33 has a light absorbing property or a light diffuse reflecting property. For example, a matte black plate is used.
By operating the rotary actuator 30,
The background plate 33 rotates about the rotation shaft 31 and is selectively located at the retreat position A and the observation position B. Departure position A is camera 5
, And the observation position B is within the field of view of the camera 5.

In FIG. 3, the ACF 2 is adhered on the transparent electrode 15 at the edge of the display panel 1. 41 is the lens barrel 6
Reference numeral 42 denotes a half mirror, and 43 denotes a light source housed in the light source unit 7.

This chip bonding apparatus has the above-described configuration. Next, the operation of bonding the chip 13 to the display panel 1 will be described. First, as shown in FIG. 1, the mounting head 8 is lowered to position the chip 13 at the focal position of the camera 5, and the camera 5 recognizes the position of the chip 13.

Next, as shown in FIG. 2, the mounting head 8 is raised to move the chip 13 upward, and the movable table 20 is driven to advance the edge of the display panel 1 above the transparent stage 3. In addition, the rotary actuator 30 is driven to move the background plate 33 to the observation position B of the camera 5 (see also FIG. 7). Then, the light source 43 is turned on, and the position of the recognition mark 14 is recognized. FIG. 3 shows the state at this time.

FIG. 4 shows an image of the recognition mark 14 at this time. Behind the display panel 1 there is a background plate 33,
There is no flickering of the screen, and the recognition mark 14 can be recognized with a clear contrast from the background.

Next, a relative displacement between the chip 13 and the display panel 1 is determined according to the result of the position recognition between the chip 13 and the recognition mark 14, and then the movable table 20 is driven to move the display panel 1 in the horizontal direction. By moving to
This displacement is corrected. In addition, the rotary actuator 30 is driven to move the background plate 33 to the retreat position A.

Next, as shown in FIG. 5, the mounting head 8 is lowered and the chip 13 is pressed against the ACF 2 to bond the chip 13 on the transparent electrode 15. In this case, the chip 13 is heated by the heat transfer of a heater (not shown) built in the mounting head 8. Next, after releasing the vacuum suction state of the chip 13 by the nozzle 12, the mounting head 8 is raised as shown in FIG. 6, and the movable table 20 is driven to move the display panel 1 off the transparent stage 3. Thus, the bonding of the chip 13 is completed.

[0023]

According to the present invention, when observing a feature such as a recognition mark formed on a transparent substrate with a camera while irradiating the transparent substrate with light from a light source, a background plate is placed behind the transparent substrate. By positioning the transparent substrate, it is possible to eliminate the flickering of the image, observe the characteristic portion of the transparent substrate with a clear contrast with the background, and accurately determine the position of the transparent substrate. The displacement between the chip and the transparent substrate is corrected based on the observation result, and the chip can be bonded onto the transparent electrode on the transparent substrate with high positional accuracy.

[Brief description of the drawings]

FIG. 1 is a side view of a chip bonding apparatus according to an embodiment of the present invention.

FIG. 2 is a side view of the chip bonding apparatus according to the embodiment of the present invention;

FIG. 3 is a side view of an optical system of the chip bonding apparatus according to the embodiment of the present invention;

FIG. 4 is an image diagram of a camera of the chip bonding apparatus according to the embodiment of the present invention;

FIG. 5 is a side view of the chip bonding apparatus according to one embodiment of the present invention;

FIG. 6 is a side view of the chip bonding apparatus according to one embodiment of the present invention;

FIG. 7 is a plan view of a background plate of a chip bonding apparatus according to an embodiment of the present invention and its rotating means.

FIG. 8 is a side view of a conventional chip bonding apparatus.

FIG. 9 is an image diagram of a camera of a conventional chip bonding apparatus.

[Explanation of symbols]

 Reference Signs List 1 display panel (transparent substrate) 3 transparent stage 5 camera 7 light source 8 mounting head 12 nozzle 13 chip 14 recognition mark 15 transparent electrode 20 movable table 25 cylinder 30 rotary actuator 33 background plate

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-4-322492 (JP, A) JP-A-5-198623 (JP, A) JP-A-8-6055 (JP, A) JP-A-8-58 152646 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) H01L 21/60 G02F 1/1345

Claims (1)

(57) [Claims] 1. A chip bonding method for bonding a chip on a transparent electrode of a transparent substrate, wherein the position of the chip is recognized by observing the chip held at the lower end of a nozzle of a mounting head with a camera below. Process, the transparent electrode of the transparent substrate is positioned above the camera, the background plate is positioned above the transparent electrode, and while illuminating light from a light source below toward the transparent substrate, the characteristic portion of the transparent substrate is removed. A step of recognizing the position of the transparent substrate by observing with a camera, a step of correcting a relative displacement between the chip and the transparent substrate according to the result of the position recognition of the chip and the transparent substrate, and a step of lowering the nozzle of the mounting head to lower the chip Bonding to a transparent electrode.