JPH0494553A - Bonding device - Google Patents

Abstract

PURPOSE:To readily adjust a parallel between a pressing surface and a loading surface by a method wherein a parallel degree between the pressing surface and the loading surface of an object to be pressed on a stage is measured and the parallel between these surfaces is maintained by means of adjusting a plane surface angle based on this information. CONSTITUTION:First, a pressing device 1 is descended to provisionally press an IC chip 42 and a TAB tape 44 by a bonding tool 12. At this time, a bending part 18 comprising a plate spring, etc., is distorted by a generating reaction and a sticked distortion gauge 62 generates output signals, which are sent to a controller 54 through an amplifier 52. Next, an inclination of a stage 32 is so computed as to make a pressurized surface 12a parallel with a surface containing a surface of an electrode 42a of an IC chip by the controller 54. As a result, the surfaces are parallel-adjusted by moving a receiver 24 by motors 29a and 29b. Thereafter, the pressing device 1 is further descended to regularly press the chip and tape. Thus, an operation of making the pressurized surface parallel with the stage can be automatized.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a bonding device used for bonding, for example, an electrode of an IC chip and a lead of a TAB tape.

[Conventional technology]

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

There is a method of connecting using ultra-fine wires for wiring (bonding wires), but a method of thermocompression bonding by sandwiching fine metal balls (hereinafter referred to as bumps) between the electrodes of the IC chip and the leads is also widely used. It is becoming more and more popular.

T A B (Tape Automated Bon
ding) method is a technique that is attracting attention as a representative of the latter. In this method, a bump is formed in advance on either the electrode of the IC chip or the tip of the lead on the TAB tape, and then the IC chip bump and the TAB tape with the lead are stacked together via a hump. The two are then joined together. In the TAB method, a large number of electrodes and leads can be bonded all at once, which enables rapid bonding work.

[Problem to be solved by the invention]

In order to uniformly and accurately bond a large number of electrodes and leads arranged in a substantially square shape using a bonding device, the pressure surface of the bonding tool that presses them during bonding must be parallel to the mounting surface of the mounting table. have to be in touch.

Conventionally, in order to adjust the parallelism between the mounting surface of the mounting table and the pressing surface of the pounding tool, a pressure film that changes color when pressure is applied has been used.

In this method, a pressure film placed on a mounting table is pressed by a bonding tool, and the inclination angle of the bonding tool is adjusted by finding a spot where uneven contact occurs based on the color of the pressure film. However, this method requires trial and error, takes time for adjustment work, and has the problem of lowering work efficiency.

The present invention has been made based on the above-mentioned circumstances, and an object of the present invention is to provide a bonding device that can easily adjust the parallelism between a pressurizing surface and a mounting surface.

[Means to solve the problem]

A bonding apparatus according to the present invention for achieving the above object is a bonding device comprising a pressing means and a mounting table disposed opposite to a pressing surface of the pressing means and on which a pressed object is placed. In the apparatus, a measuring means for measuring parallelism between a pressing surface of the pressing means and a surface of the mounting table on which the object to be pressed is placed, and adjusting an inclination angle of at least one of the pressing means and the mounting table. A plane angle adjusting means and a control means for controlling the plane angle adjusting means so as to maintain parallelism between the pressurizing surface and the surface on which the pressed body is placed based on information from the measuring means. It is characterized by this.

The measuring means includes at least three pressure measuring bags that measure the reaction of the pressing force when pressed by the pressing means! It is desirable that

The measuring means includes at least three distance measuring bags for measuring the distance between the pressing surface of the pressing means and the surface of the mounting table on which the object to be pressed is placed! It may be.

[Effect]

In the present invention, with the above configuration, the measuring means measures the parallelism between the pressing surface of the pressing means and the surface of the mounting table on which the pressed object is placed (hereinafter also referred to as the mounting surface), and transmits the information to the control means. send to The control means analyzes the parallel deviation between the pressurizing surface and the mounting surface based on the information sent from the measuring means, and uses the plane angle adjustment means, for example, by changing the inclination of the mounting table.
After maintaining parallelism between the pressing surface and the mounting surface, the pressing means is lowered to press the object to be pressed.

By using the measuring means as at least three pressure measuring devices that measure the reaction of the pressing force when the pressing means presses, the reaction of the pressing force when the placing surface is pressed by the pressing surface can be measured at three locations. Measure and send the information to the control means. Also, for example, place the object to be pressed on the mounting table! Since it is possible to measure the reaction when pressed by the pressurizing surface, it is also possible to maintain parallelism between the pressurizing surface and the joint surface of the pressed body.

Furthermore, by using the measuring means as at least three distance measuring devices that measure the distance between the pressing surface of the pressing means and the surface of the mounting table on which the pressed object is placed, the distance between the pressing surface and the mounting surface can be measured. Measurements are taken at three locations and the information is sent to the control means.

〔Example〕

A first embodiment of the present invention will be described below with reference to FIGS. 1 to 3. FIG. 1 is a schematic configuration diagram of a bonding device according to a first embodiment of the present invention, FIG. 2 is a schematic perspective view of a pressing device of this bonding device, and FIG. 3 is a θy stage (gonio In this embodiment, a case will be described in which a bump joins an IC chip to a TAB tape that is thermocompression bonded to the tip of a lead.

The bonding device shown in FIGS. 1 and 2 includes a pressing device 1 having a bonding tool 12 and a pressure head 14 that holds the bonding tool 12, and a mounting table disposed opposite to the bonding tool 12. 32 and a θx-θy stage 2 provided with a mounting table 32, the receiver includes a device 4 and a control section 50.

The pounding tool 12 has a flexible portion 1 suspended between a support plate 16 provided on the side surface of the lower part and a pressure head 14.
It is held on the pressure head 14 via 8. The flexible portions 18 are formed of flexible members, such as leaf springs, and each of the four flexible portions 18 is provided with a strain gauge 62 that measures the load using the strain of each of the four flexible portions 18.

Further, the bonding tool 12 has a built-in heater (not shown) for heating the tip portion to 500°C.

θX-θy of the bonding device shown in Figures 1 and 3
The stage 2 includes a pedestal 24 for fixing the pedestal 32, two worm gear devices 26a and 26b provided at the lower part of the pedestal 24, and a worm gear device for adjusting the plane angle of the pedestal 24. Motors 29a, 2 that drive 26a26b
9b. An x-y coordinate system (orthogonal coordinate system) is taken on the top surface of the IC chip 42 when the IC chip 42 is placed in the center of the mounting table 32, and the rotation angle around the X axis is θ8, y Let the rotation angle around the axis be θa.

The θx-θy stage 2 has a mounting base 32 and a support base 24 that are integrally rotated freely around the X-axis and the y-axis, and has an angle adjustment resolution of 0.001 degrees. The worm gear device 26 includes a worm gear 27 and a worm 28 connected to a motor 29. In order to rotate the stand 24 by a predetermined angle around the
The shaft rotates as the rotation axis, and the receiver is connected to the worm gear 2 by the base 24.
Rotates together with 7a. Also, θ.

By driving the positioning motor 29b and operating the worm gear device 26b, the receiver can rotate the base 24 around the y-axis.

Note that an IC chip 42 is placed on the mounting surface of the mounting table 32, and above this IC chip 42 is a T-shirt that moves horizontally.
AB tape 44 is placed.

The control device 50 includes an amplifier 52 that amplifies the electrical signal from the strain gauge 62, a controller 54 that analyzes the amplified signal, a storage section 56 that stores information regarding the load, and a controller 54 that controls the motors 29a and 29b according to instructions from the controller 54.
A driver 58 for driving the . The strain gauge 62 is a pressure measuring device that measures pressure by converting deformation caused by pressure into a change in electrical resistance.

To bond the electrodes 42a of the IC chip 42 and the leads 44a of the TA, B tape 44, first, the pressing device 1 is lowered, and the bonding tool 12 connects the IC chip 42 and the TAB tape 44 via the bumps 46. Apply temporary pressure, for example, with a load about half of the actual pressure. This results in
A reaction occurs to the force pressing the IC chip 42, and the bending portion 18 is distorted by this reaction. This strain is measured by four strain gauges 62, and the output signal from each strain gauge 62 is amplified by the amplifier 52 and then sent to the controller 54. The controller 54 analyzes the information sent from the four strain gauges 62 and makes sure that the load applied to the IC chip 42 is uniform, that is, the pressure surface 12a of the pounding tool 12 and the electrode 42 of the IC chip 42 are
A plane including the surface of a (hereinafter referred to as the joint surface 42b)
The inclination of the mounting table 32 is calculated so that the two are parallel to each other. This result is stored in the storage unit 56, and the driver 58
The receiver drives the θ8 positioning motor 29a and the θa positioning motor 29b via the receiver to adjust the table 24 to a desired angle. In this way, after adjusting the parallelism between the pressing surface 12a of the bonding tool 12 and the bonding surface 42b of the IC chip 42 by measuring the load when temporarily pressed,
By further lowering the pressing device 1 and performing the final pressing, the electrodes 42a of the IC chip 42 and TAB are connected via the bumps 46.
The lead 44a of the tape 44 is joined. In this way, T
A large number of leads 44a provided on one frame of the AB tape 44 and the electrodes 42a of the IC chip 42 are bonded together. When one IC chip 42 is bonded, the frame of the next TAB tape is transferred to the bonding tool 1 by a TAB tape feeding mechanism (not shown).
At the same time, another IC chip is carried onto the mounting table 32 by a transfer means (not shown).

Then, the same steps as above are repeated.

Note that if the pressing time by the bonding tool 12 is short and real-time control as described above cannot be performed, the angle of the support 24 is adjusted based on the information stored in the storage unit 56 during the previous bonding. The storage unit 56 may be omitted if real-time control is possible as described above.

Further, by pressing the bonding 12 without placing an IC chip, it is possible to automatically maintain parallelism between the pressing surface and the mounting surface.

In the bonding apparatus of this embodiment described above, not only can the pressing surface and the mounting surface be parallel to each other, but also the bonding tool can be made parallel to each other, for example.

It is also possible to automatically maintain parallelism between the pressing surface and the joining surface by measuring the reaction of the pressing force that presses the joining surface of the tap and making this force uniform. By pressing each electrode of the IC chip and the bump with such uniform force, these can be reliably joined and the yield at the time of joining can be improved. Furthermore, according to this embodiment, it is also possible to control the bonding process online.

Next, a second embodiment of the present invention will be described with reference to FIGS. 4 and 5. FIG. 4 is a schematic configuration diagram of a bonding device according to a second embodiment of the present invention, and FIG. 5 is a schematic enlarged view of a pressing device and a receiver of the bonding device. The second embodiment differs from the first embodiment in that four pencil-type electric micrometers 64 are used as measuring means.

In the second embodiment, parts having the same functions as those shown in FIGS. 1 to 3 are denoted by the same reference numerals, and detailed explanation thereof will be omitted.

The electric micrometer 64 is a contact displacement measuring device,
In this embodiment, four electric micrometers 64 are capable of measuring minute displacements with an accuracy of 1 μm, and a plane (hereinafter referred to as a reference plane 6.4b) formed by the tips of the four electric micrometers 64 is used.

) is attached to the bonding tool 12 via a fixture 15 so that the pressurizing surface 12a of the bonding tool 12 is parallel to the pressurizing surface 12a of the bonding tool 12. In addition, the bonding tool 12
is held by a holding section 140. However, as shown in FIG. 5, the electric micrometer 64 is placed at a part of the corner of the side surface of the bonding tool 12 so as not to come into contact with the TAB tape 44.

Using an electric micrometer, the parallelism of a specific surface can be measured as follows. Three or more electric micrometers are arranged so that the probes at their tips are located on the same plane. These electric micrometers are brought into contact with a specific surface to measure displacement, and by comparing the measured displacements, it is determined whether the specific surface is parallel to the reference plane of the electric micrometer.

In order to bond the electrodes of the IC chip 42 and the reeds of the TAB tape 44 using this bonding device, first, the pressing device 100 is lowered, and the distance between the pressing surface 12a of the bonding tool 12 and the surface of the TAB tape 44 is 2 to 2. When it approaches 4mm or less, it stops once. This is because the stroke of commercially available electric micrometers is 2 to 4 mm.

Here, the parallelism of the mounting surface 32a of the mounting unit 32 is measured using the electric micromake 64. The signal from the electric micrometer 64 is amplified by the amplifier 52 of the control section 500 and then sent to the controller 54. The controller 54 analyzes the sent information and adjusts the mounting surface 3 of the mounting table 32.
The inclination of the mounting table 32 is calculated so that the electric micrometer 2a and the reference plane 64b of the electric micrometer 64 are parallel to each other. Then, the θX positioning motor 29a and the θA positioning motor 29b are driven via the driver 58, and the angle of the receiver base 24 is adjusted. After adjusting the base 24 in this manner, the pressing device 100 is further lowered, and the electrodes of the IC chip 42 and the leat of the TAB tape 44 are bonded by thermocompression via the bumps by the bonding tool 12. In this way, a large number of leads provided on one frame of the TAB tape 44 and an I
The electrodes of the C chip 42 are bonded together.

In the bonding apparatus of this embodiment, the angle of the θX-θy stage can be adjusted based on information measured when the bonding tool is not in contact with the IC chip, so complete online control is possible. Other functions and effects are the same as in the first embodiment.

In the second embodiment, an electric micrometer that measures by contact is used as the measuring means, but the present invention is not limited to this, and the measuring means may be a non-contact type. A displacement sensor may also be used.

In addition, in the first and second embodiments described above, a case was explained in which the inclination of the receiver was changed using the θχ-θy stage when adjusting the parallelism between the pressurizing surface and the mounting surface, but the present invention is not limited to this, and instead of using the θx-θy stage, a mechanism for adjusting the inclination of the pounding tool may be provided on the pressing device side.

Furthermore, in the above second and second embodiments, the case where the lead of the TAB tape on which the hump has already been formed and the electrode of the IC chip is bonded is explained, but the present invention is not limited to this. Instead, the present device can also be used when thermocompression bonding a large number of fine metal balls that will become a hump to the lead end of a TAB tape at once. Therefore, this bonding device can be used twice in the process of manufacturing the humped TAB tape and the process of bonding the TAB tape and the IC chip.

〔Effect of the invention〕

As explained above, according to the present invention, it is possible to automatically make the pressing surface of the pressing means and the mounting surface of the mounting table parallel to each other, thereby improving the working efficiency and joining. It is possible to provide a bonding apparatus that can simultaneously improve yield when bonding.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram of a bonding device according to a first embodiment of the present invention, FIG. 2 is a schematic perspective view of a pressing device of this bonding device, and FIG. 3 is a θX-
FIG. 4 is a schematic perspective view of a θy stage, FIG. 4 is a schematic configuration diagram of a bonding device according to a second embodiment of the present invention, and FIG. 5 is a schematic enlarged view of a pressing device and a support of the bonding device. 1.100... Pressing device, 2... θX-θy stage, 4... Support is device, 12
...Ponding tool, 12a...Pressure surface, 14
．． 140・1. Holding part, 15... Mounting tool, I6...
Support plate, 18... Flexible portion, 24... Receiver is stand, 26a, 26b... Worm gear device, 27a...
Worm gear, 28a...Worm, 29a...
29 b---motor, 32 ・, mounting table, 32a
Placement surface, 42... IC chip, 42a...
Electrode, 42b... joint surface, 44... TAB tape,
44 a---Lead, 46...Hump, 50.5
00...Control unit, 52...Amplifier, 54...Controller, 56...Storage unit, 5th...Driver,
62...distortion gamer 64-,, electric micrometer,
64a... Measuring head, 64b... Reference surface.

Claims (3)

[Claims] (1) In a bonding device comprising a pressing means and a mounting table disposed opposite to a pressing surface of the pressing means and on which a pressed object is placed, the pressing surface of the pressing means and the mounting table are provided. a measuring means for measuring parallelism with a surface on which the object to be pressed is placed; a plane angle adjusting means for adjusting the inclination angle of at least one of the pressing means and the mounting table; and information from the measuring means. 1. A bonding apparatus comprising: control means for controlling said plane angle adjusting means so as to maintain parallelism between said pressurizing surface and a surface on which said object to be pressed is placed. (2) The bonding apparatus according to claim 1, wherein the measuring means is at least three pressure measuring devices that measure the reaction of the pressing force when the pressing means presses. (3) The bonding apparatus according to claim 1, wherein the measuring means is at least three distance measuring devices that measure the distance between the pressing surface of the pressing means and the surface of the mounting table on which the object to be pressed is placed.