JPH0770564B2 - Bonding device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a bonding apparatus used when, for example, an electrode of an IC chip and a lead of a TAB tape are bonded.

[Conventional technology]

Various methods are used to connect the electrodes of the IC chip to the external leads.

There is also a method of connecting using an ultrafine wire for wiring (bonding wire), but a method of sandwiching a fine metal piece (hereinafter referred to as a bump) between an IC chip electrode and a lead and performing thermocompression bonding is also widely used. It is like this.

The TAB (Tape Automated Bonding) method is drawing attention as a representative of the latter. In this method, bumps are formed in advance either on the electrodes of the IC chip or on the lead tips on the TAB tape, and then the electrodes of the IC chip and the TAB tape having the leads are superposed via the bumps. To join the two. In the TAB method, since a large number of electrodes and leads can be joined at once, a quick bonding operation becomes possible.

[Problems to be Solved by the Invention]

FIG. 2 is a schematic view of a conventional bonding apparatus. Second
The bonding apparatus shown in the figure is a mounting table on which a bonding tool 52 that can be raised and lowered and an IC chip 62 are mounted.
54 and. In the figure, 64 is a TAB tape and 66 is a bump.

In order to uniformly and accurately bond the leads and the large number of electrodes arranged in a substantially square shape by the bonding device, the pressing surface 52a of the bonding tool 52 that presses the electrodes during bonding is used.
Must be in parallel contact with a surface (hereinafter also referred to as a mounting surface) 54a of the mounting table 54 on which the IC chip 62 is mounted.
However, in the conventional bonding apparatus, the bonding tool 52 and the mounting table 54 on which the IC chip 62 and the like are mounted are separately fixed, and furthermore, the IC chip 62 of about 1 cm square is bonded. Pressing surface of bonding tool 52
The area of the mounting surface 54a of the mounting table 54a and 52a is small. Therefore, due to external factors such as vibration, the pressing surface 52a of the bonding tool 52 and the mounting surface 54a of the mounting table 54 are displaced from each other in parallel during pressing, or the bonding tool 52 and the mounting table 54 are positioned in the lateral direction. There was a case where there was a gap. Further, there is a problem that the pressing surface 52a of the bonding tool 52 and the mounting surface 54a of the mounting table 54 are likely to be out of parallel with each other due to long-term use. In this way, the pressure surface 52a of the bonding tool 52 is
If the parallelism between the mounting surface 54a and the mounting surface 54a of the mounting table 54 deviates, the yield at the time of bonding the IC chip 62 and the TAB tape 64 deteriorates due to defective bonding.

Further, when the IC chip 62 and the TAB tape 64 are joined, the bump 66 deforms only about 5 μm. Therefore, even if the pressure surface 52a and the mounting surface 54a are slightly deviated from each other in parallel,
Since joining failure occurs, the parallelism between the pressure surface 52a and the mounting surface 54a must be maintained with high accuracy. However, in the conventional bonding apparatus, since the pressing surface 52a of the bonding tool 52 and the mounting surface 54a of the mounting table 54 have substantially the same size as the size of the IC chip 62 as described above, it is approximately 1 cm square. There has been a problem that adjustment work has to be troublesome because it is necessary to perform adjustment so as to maintain parallelism between narrow planes.

The present invention has been made based on the above circumstances, and an object of the present invention is to provide a bonding apparatus that can efficiently perform the work of adjusting the parallelism, and can surely perform the bonding to improve the yield. It is what

[Means for Solving the Problems] A bonding apparatus for achieving the above object is a pressing means, a holding portion that holds the pressing means, and is arranged to face the pressing surface of the pressing means, and In a bonding apparatus comprising a mounting table for mounting a pressed body,
The holding part is formed so as to slidably hold the pressing means, and a moving means for moving the holding part is provided. When the holding part is moved by the moving means, the conveyance path of the pressed body is excluded. When the lower surface of the holding portion and the peripheral portion of the upper surface of the mounting table contact each other and the lower surface and the peripheral portion contact each other, the pressing surface of the pressing means and the pressed body of the mounting table are mounted. The holding part and the mounting table are formed so that the surfaces to be parallel to each other are parallel to each other, and the lower surface of the holding part is brought into contact with the peripheral portion of the upper surface of the mounting table by the moving means, and then the pressing means covers the surface. It is characterized in that it is configured to press the pressing body.

Further, it is desirable that at least one of the holding portion and the mounting table is supported via an elastic member.

[Action]

According to the present invention, according to the above-described structure, first, the holding portion is moved so that the lower surface of the holding portion abuts on the peripheral portion of the upper surface of the mounting table. As a result, the holding portion and the mounting table are integrated, and the pressing surface of the pressing means and the surface (mounting surface) of the mounting table on which the pressed body is mounted are kept parallel. In this state, by lowering the pressing means, a uniform load is applied to the pressed body mounted on the mounting table while keeping the pressing surface of the pressing means and the mounting surface of the mounting table parallel to each other. By forming the holding portion and the mounting table so that the contact surface between them becomes large, it is possible to easily adjust the parallelism between the pressing surface of the pressing means and the mounting surface of the mounting table.

Further, by configuring at least one of the holding part and the mounting table to be supported via the elastic member, when the elastic member is provided on the mounting table side, for example, when the holding part presses the mounting table, the elastic force is applied. By elastically deforming the member, the upper surface of the mounting table automatically follows the lower surface of the holding section, so that the holding section and the mounting table are integrated. Thus, for example, when the holding section is inclined with respect to the horizontal, the mounting table automatically tilts following the holding section, and the pressure surface of the pressing means and the mounting surface of the mounting table are automatically maintained parallel to each other.

〔Example〕

An embodiment of the present invention will be described below with reference to FIG. FIG. 1 is a schematic front view of a bonding apparatus which is an embodiment of the present invention. In this embodiment, a case will be described in which a TAB tape in which bumps are thermocompression-bonded to the lead tips is joined to an IC chip.

The bonding apparatus shown in FIG. 1 is provided with a pressing tool 2 having a bonding tool (pressing means) 12 and a pressure head (holding section) 14 for holding the bonding tool 12, and facing the pressing apparatus 2. The receiving device 4 is included. The bonding tool 12 has a built-in heater (not shown) for heating the tip portion to a temperature of about 500 ° C. The pressure head 14 has a bonding tool 12
A sliding bearing 16 for slidably holding the side surface of the sliding bearing 16 is provided. The receiving device 4 includes a mounting table 22 on which the IC chip 32 is mounted.
And a plurality of springs (elastic members) 26 provided below the mounting table 22.

The pressure head 14 and the mounting table 22 are the lower surface 14a of the pressure head 14.
And the peripheral portion 22b of the upper surface of the mounting table 22 are brought into contact with each other, the pressing surface 12a of the bonding tool 12 and the mounting surface 22a of the mounting table 22 on which the IC chip is mounted are formed to be parallel to each other. There is. That is, in this embodiment, the pressing surface 12a of the bonding tool 12, the lower surface 14a of the pressing head 14, the peripheral portion 22b of the lower surface of the mounting table 22 and the mounting surface 22a of the mounting table 22 are formed in parallel. A knock pin 18 is formed on the lower surface 14a of the pressure head 14, and a concave portion 28 corresponding to the knock pin 18 is formed on the peripheral portion 22b of the upper surface of the mounting table 22. The knock pin 18 and the concave portion 28 ensure the lateral alignment in the same figure and prevent the lateral displacement of the pressure surface 12a and the mounting surface 22a during the pressure application. Also, the mounting table
In the space between 22 and the bonding tool 12, a TAB tape 34 with bumps is arranged which moves in a direction perpendicular to the plane of the drawing.

In this embodiment, bumps formed to have a uniform size are used for joining the IC chip 32 and the TAB tape. This is because after processing the metal used as the material for bumps into fine wires, which the applicants previously applied (Japanese Patent Application No. 1-320296), the metal wires are cut to a fixed length and the distance between them is reduced. It can be easily formed by a method of melting and solidifying in a separated state, and utilizing surface tension to obtain spherical uniform bumps.

In order to join the electrodes of the IC chip 32 and the leads of the TAB tape 34, first, the pressing device 2 is lowered by an elevating device (moving means) (not shown), the knock pin 18 is fitted into the recess 28, and the lower surface 14a of the pressure head 14 is pressed. And the peripheral portion 22b on the upper surface of the mounting table 22 are brought into contact with each other to integrate the pressing device 2 and the receiving device 4. At this time, since the spring 26 is provided in the lower portion of the mounting table 22, the lower surface 14a of the pressure head 14 elastically deforms due to the force of pushing the upper surface of the mounting table 22, so that, for example, the pressure head 14 is Even if it is inclined with respect to the horizontal, the peripheral portion 22b of the upper surface of the mounting table 22 has the pressing head 14
Automatically follows so as to contact the lower surface 14a of the. At this stage, the pressing surface 12a of the bonding tool 12 and the mounting surface 22a of the mounting table 22 are kept parallel to each other. In this way the pressure surface 1
The bonding tool 12 is lowered by lowering the bonding tool 12 after ensuring the parallelism between the mounting surface 22a and the mounting surface 22a.
Since the pressing surface 12a of the mounting table 22 descends while keeping parallel to the mounting surface 22a of the mounting table 22, a uniform load is applied to the bonding surface between each electrode of the IC chip 32 and the bump of the lead. Thus, TAB
A number of leads on one frame of tape 34
The electrodes of the IC chip 32 are collectively bonded. When one IC chip 32 is bonded, the TAB tape feeding mechanism (not shown) conveys the frame of the next TAB tape directly below the bonding tool 12, and another IC chip is conveyed by a conveying device (not shown). It is carried on the mounting table 22, and the above bonding operation is repeated.

In the bonding apparatus of this embodiment, the pressing device 2 and the receiving device 4 are flat surfaces larger than the pressing surface 12a and the mounting surface 22a, that is, the lower surface 14a of the pressing head 14 and the peripheral portion 22b of the upper surface of the mounting table 22.
Since the joining is performed after the and are brought into contact with each other and integrated, even if an external factor such as a vibration occurs during the joining, the parallelism is not impaired and the joining can be reliably performed. Therefore, the parallelism between the pressure surface 12a and the mounting surface 22a can be stably maintained even when used for a long time. Further, according to the present embodiment, since the force applied to the bonding surface between each electrode of the IC chip and the bump of the lead becomes uniform, it is possible to reliably bond them, and it is possible to reduce the bonding failure and The yield can be improved. Further, since the pressing surface of the bonding tool and the mounting surface of the mounting table are automatically adjusted in parallel, the work efficiency can be improved.

In the above embodiment, the elastic member (spring)
However, the present invention is not limited to this, and for example, the spring may be provided above the pressure head. Further, in the present invention, the spring may not be provided, and even when the spring is not provided, the lower surface 14a of the pressure head 14 and the peripheral portion 22b of the upper surface of the mounting table 22 which are wider than the pressure surface of the bonding tool. Since it is possible to adjust the parallelism between the pressing surface 12a and the mounting surface 22a, it becomes extremely easy to adjust the parallelism between the pressing surface 12a of the bonding tool 12 and the mounting surface 22a of the mounting table 22. In addition, as compared with the conventional bonding apparatus, it is possible to easily maintain the parallelism between the pressing surface of the bonding tool and the mounting surface of the mounting table with high accuracy.

Further, in the above embodiment, the case where the spring is used as the elastic member has been described, but the present invention is not limited to this, and a rubber tube or the like filled with a liquid may be used as the elastic member. Good.

Furthermore, in the above embodiment, the case where the pressure head moves up and down has been described, but the pressure head may be moved in the direction perpendicular to the paper surface of FIG.

In addition, in the above embodiment, the case where the leads of the TAB tape on which the bumps are already formed and the electrodes of the IC chip are bonded has been described, but the present invention is not limited to this, and the TAB tape The present apparatus can also be used when the bumps are collectively thermocompression-bonded to the lead tips.
Therefore, this bonding equipment is
It can be used twice in the tape manufacturing process and the process of joining the TAB tape and the IC chip.

Needless to say, the present device can also be used for bonding with a TAB tape when bumps are formed on the electrode side of an IC chip.

〔The invention's effect〕

As described above, according to the present invention, the parallelism between the pressing surface of the pressing means and the mounting surface of the mounting table can be easily adjusted with high accuracy by the lower surface of the wide holding portion and the peripheral portion of the upper surface of the mounting table. Therefore, it is possible to provide a bonding apparatus capable of improving the efficiency of the adjustment work and improving the yield when, for example, the IC chip and the TAB tape are bonded via the bump.

[Brief description of drawings]

FIG. 1 is a schematic front view of a bonding apparatus which is an embodiment of the present invention, and FIG. 2 is a schematic view of a conventional bonding apparatus. 2 ... Pressing device, 4 ... Receiving device, 12 ... Bonding tool, 12a ... Pressurizing surface, 14 ... Pressurizing head, 14a ... Pressurizing head lower surface, 16 ... Sliding bearing, 18 ... Knock pin , 22 ... mounting table, 22a ... mounting surface, 22b ... peripheral part of the mounting table upper surface, 26 ... spring, 28 ... recess, 32 ... IC chip, 34 ... TAB tape.

Claims (2)

[Claims] 1. A bonding apparatus comprising: pressing means; a holding portion for holding the pressing means; and a mounting table which is arranged to face a pressing surface of the pressing means and on which a pressed body is mounted. In which the holding part is formed so as to slidably hold the pressing means, and a moving means for moving the holding part is provided, and when the holding part is moved by the moving means, a conveying path for the body to be pressed. Except for the lower surface of the holding portion and the peripheral portion of the upper surface of the mounting table contact, and when the lower surface and the peripheral portion contact, the pressing surface of the pressing means and the pressed body of the mounting table. The holding unit and the mounting table are formed so that the mounting surface is parallel to each other, and the lower surface of the holding unit is brought into contact with the peripheral portion of the upper surface of the mounting table by the moving unit, and then the pressing unit. Characterized by being configured to press the pressed body by Bonding apparatus to be. 2. The bonding apparatus according to claim 1, wherein at least one of the holding portion and the mounting table is supported by an elastic member.