JP3173153B2 - Lead bonding equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lead bonding apparatus, and more particularly to a lead bonding apparatus for positioning an electric component such as a substrate or a semiconductor chip and bonding a device lead to an electrode of the electric component.

[0002]

2. Description of the Related Art A device manufacturing process known as a TAB method includes an inner lead bonding process of bonding a chip to a lead of a film carrier, and an outer lead for bonding a device lead obtained by punching the film carrier to a substrate. Consists of a bonding process.

[0003]

An inner lead bonding apparatus for automatically performing inner lead bonding has been fairly widely used for practical use.
However, the outer lead bonding requires extremely high precision, especially when the upper surface of the substrate is slightly inclined due to molding errors, etc., and all leads are evenly pressed to the electrodes of the substrate with even force. Because it is extremely difficult to do this, the technology for doing this automatically is not well established, and at present, outer lead bonding is currently performed exclusively by manual work. .

Accordingly, the present invention is directed to a bonding apparatus for bonding electrodes and leads of an electric component such as a substrate or a semiconductor chip, and in particular, even if the upper surface of the substrate is inclined, all leads are evenly applied to the electrodes of the electric component. It is an object of the present invention to provide a lead bonding apparatus capable of bonding a lead.

[0005]

For this purpose, the present invention provides a holder, a gimbal spring held by the holder ,
The positioning part of the electric component mounted on the center of this gimbal spring, and the position interposed between the holder and the positioning part
A steel ball which supports swingably the deciding part from below, the electrode of the electrical components mounted on the positioning portion, to pressing from above the presser of the bonding head in the pressed lead, the holder of the positioning unit And the steel ball
Push-up means for pushing up from below through the
Load detecting element for detecting the load
Pressing by the push-up means according to the detection signal of the detecting element
And a control unit for controlling the force .

[0006]

In the above construction, the device is positioned on an electric component such as a substrate positioned at the positioning portion by the bonding head, and the lead of the device is pressed against the electrode of the substrate by the pressing element. In this case, even if the upper surface of the substrate is inclined, the substrate is held by a swingable holder, so that when the pressing element is pressed against the lead, the substrate is oriented so that it follows the lower surface of the pressing element due to the load. Is corrected. Then, when the push-up means is driven to push up the substrate, the leads are strongly pressed against the pressing element, and all the leads are bonded to the electrodes of the substrate with an equal force.

[0007]

Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view of a bonding apparatus, and FIG. 2 is a front view. In this apparatus, a lead L of a device P manufactured by a TAB method is outer-bonded to an electrode 70 of a substrate 20 as an electric component. The device P includes a film carrier to which a semiconductor chip cut out from a wafer is bonded and which is bonded to an upper mold 41 and a lower mold 4.
It was made by stamping with 2.

[0008] 1 is an ultra-thin disk-shaped gimbal spring,
The positioning portion 2 of the substrate 20 is mounted at the center thereof. The positioning portion 2 has a disk shape, and a receiving portion 3 of the substrate 20 is formed in a frame shape on an upper surface thereof, and a suction hole 4 is formed in the inside thereof. This suction hole 4
The substrate 20 on the receiving portion 3 is fixed by vacuum suction so as not to rattle during the bonding. 5 is a set screw.

The gimbal spring 1 has an arc-shaped slit 11.
Are formed alternately at different positions (see also FIG. 3). Therefore, this gimbal spring 1 is freely bendable in all directions, and a positioning portion 2 mounted at the center thereof.
Is swingable up and down.

The outer edge of the gimbal spring 1 is held by a holder 12 by a set screw 13. In FIG. 2, reference numeral 14 denotes a lower receiving member provided below the positioning portion 2. The lower receiving member 14 is coupled to the inner peripheral edge of the gimbal spring 1 by the set screw 5 so as to be held between the positioning portion 2 and the lower receiving member 14. I have. A heater 15 is provided on the lower surface of the positioning unit 2.
Is provided. The heater 15 connects the lead L to the substrate 2
The substrate 20 is heated via the positioning portion 2 so that the substrate 20 can be easily bonded to the zero electrode.

In FIG. 2, the lower receiving member 14 and the holder 1
Between the two, a universal joint made of a steel ball 16 is interposed. Therefore, the lower receiving member 14 and the positioning part 2 integral with the lower receiving member 14 are supported on the steel ball 16 so as to be swingable from below. A large load applied to the positioning portion 2 is supported by the holder 12 via the steel ball 16.

A cylindrical portion 12a is suspended from the lower surface of the holder 12, and the cylindrical portion 12a is rotatably held by a lifting plate 44 via a bearing 43 in a horizontal direction. 54
Reference numeral denotes a friction roller which is in contact with the outer peripheral surface of the holder 12, and is inserted into a rotating shaft 56 of a motor 55 provided at an end of the elevating plate 44. When the roller 54 is rotated by the drive of the motor 55, the holder 1
2 rotates in the horizontal direction about the axis of the bearing 43. A gear is provided in place of the roller 54, and the holder 12
A tooth profile that engages with this gear may be formed on the peripheral surface of the holder 12, so that the holder 12 can be surely rotated by a predetermined amount without slipping.

In FIGS. 1 and 2, guide shafts 45 are projected from the lower surfaces of the four corners of the lift plate 44, and the guide shaft 45 is attached to a base 46 provided below the lift plate 44. It is inserted into guide rings 47 erected at four corners so as to be able to move up and down. In FIG. 2, a cylinder 17 is provided at a central portion of the base 46 as a pushing-up means for pushing up the steel ball 16, and a load applied to the positioning portion 2 is provided on a receiving seat 18 a attached to the tip of the rod 18. A load cell 48 is provided as a load detecting element for detecting the load. The load detector 49 projecting from the upper surface of the load cell 48 is in contact with the center of the lower surface of the holder 12.
When the rod 18 of the cylinder 17 is retracted,
2 is vertically guided by the guide rod 45 and the guide ring 47, whereby the positioning unit 2 is moved up and down. The base 46 is installed on the X table 21 and the Y table 22, and when these tables 21 and 22 are driven, the positioning unit 2 moves horizontally in the XY directions.

In FIG. 2, reference numeral 50 denotes a switch valve connected to the cylinder 17, and reference numeral 51 denotes a pressure adjusting regulator connected to the cylinder 17. 51a is an air tube, 53 is a load cell 48 and a pressure regulating regulator 5.
And a compressor 59 connected to the switch valve 50 and a CPU 59 as a control unit for controlling the control valve 1 and the like.

In FIG. 1, reference numeral 24 denotes a first head, which picks up a substrate 20 provided on a tray (not shown) by vacuum suction to a nozzle 25 thereof, and transfers and mounts the substrate 20 on the positioning unit 2. Reference numeral 26 denotes a second head, which vacuum-adsorbs the device P on the lower die 42 to the nozzle 27 thereof, picks up the device P, and transfers the device P onto the substrate 20 mounted on the positioning unit 2. The head 26 has a thermocompressor 2 as a presser for pressing the lead L against the electrode of the substrate 20 for bonding.
8 are provided. The first head 24 is mounted on a first moving table 62, and the second head 26 is mounted on a second moving table 63, and each moves in the XY directions.

Reference numeral 29 denotes a camera disposed below the moving path of the second head 26 to observe the device P. A laser device 57 for detecting floating of the lead L is provided on a side portion of the camera 29. The laser device 57 irradiates the lead L with laser light from the light emitting unit 57a and receives the reflected light at the light receiving unit 57b, thereby detecting the floating of the lead L (whether the lead L is bent upward). A camera 58 for observing the substrate 20 mounted on the positioning unit 2 is disposed above the positioning unit 2. Reference numeral 60 denotes a table on which the camera 29 and the laser device 57 are installed.
This is a dump box provided on the top of the box. This apparatus has the above-described configuration, and the operation will be described next.

First, the first head 24 arrives immediately above the positioning section 2, and the substrate 20 vacuum-adsorbed to the nozzle 25 is mounted on the positioning section 2 and retracted to the side. The second head 2 which is punched by the upper die 41 and the lower die 42 and vacuum-adsorbs and picks up the device P located on the lower die 42.
Numeral 6 arrives above the camera 29 and the laser device 57, and the displacement and lifting of the lead L in the XYθ directions are measured. If the laser device 57 detects that the lead L floats above the allowable value, the device P is discarded in the dump box 61 as a defective device.

Next, the head 26 moves above the positioning portion 2. Prior to this, the position of the electrode 70 of the substrate 20 mounted on the positioning portion 2 is detected by the camera 58, and the lead L and the substrate are detected. According to the measurement result of the 20 electrodes 70, the lead L and the electrode 70 match,
The X table 21 and the Y table 22 are driven to move the substrate 20 in the XY directions, and the motor 55 is driven to drive the substrate 2
Rotate 0 horizontally. After correcting the misalignment in the XYθ direction in this way, the thermocompression bonding element 28 is lowered as shown in FIG. 4A, and the lower surface thereof is pressed against the upper surface of the lead L. Bend into a key shape as shown. Then, while the thermocompression bonding element 28 is pressed against the lead L, as shown in FIG.
The device P is mounted on the substrate 20 by lowering the thermocompression bonding element 7 and the thermocompressor 28. Then, the lead L is pressed against the electrode 70 of the substrate 20 by the thermocompression element 28. At this time, cylinder 1
The rod 18 supports the holder 12 with a small force.

Here, as shown in FIG.
When the upper surface of the substrate 20 is inclined (inclination angle α), the gimbal spring 1 is bent, so that the posture of the substrate 20 is corrected so that the upper surface of the substrate 20 is horizontal as shown in FIG. . As described above, according to the present means, even if the upper surface of the substrate 20 is inclined, the posture can be corrected so that the upper surface follows the lower surface of the thermocompression bonding element 28.

The reason why the upper surface of the substrate 20 is made horizontal is as follows. That is, the upper surface of the substrate 20 positioned by the positioning unit 2 is not limited to a perfect horizontal plane, and may be inclined due to molding errors and the like.
Is slightly inclined, the thermocompression bonding element 28 cannot press all the leads L against the electrode 70 of the substrate 20 with a uniform force, and uneven pressing occurs to prevent good bonding.

After the posture of the substrate 20 is corrected as described above, the pushing force of the rod 18 of the cylinder 17 is increased. Then, the holder 12 is strongly pushed up, whereby the positioning portion 2 is pushed up through the steel ball 16, and the electrode 70 of the substrate 20 is strongly pressed against the lead L, and the lead L is firmly bonded to the electrode 70. Such switching of the force of the cylinder 17 is performed by the regulator 51 for pressure adjustment. At this time, the electrode 7
0 is applied to the lead L by the load cell 48 detecting the pressing force and sending a signal to the CPU 53 so that the pressing force of the cylinder 17 is adjusted to the set pressing force.
Is carried out.

As described above, in this apparatus, when the device P is mounted on the substrate 20, the posture of the substrate 20 is corrected by the gimbal spring 1 so that the upper surface of the substrate 20 is horizontal, and then the rod 18 is projected by the cylinder 17. Since the thermocompression bonding element 28 is pressed against all the leads L with an equal load, all the leads L can be bonded to the substrate 20 without pressing. Note that the rod 18 is
May be slightly projected to correct the posture of the substrate 20 so that the upper surface of the substrate 20 is horizontal, and then the cylinder 18 may further project the rod 18 to obtain a large pressing force. In addition, this apparatus is applicable not only to outer lead bonding but also to inner lead bonding.

[0023]

As described above, the present invention provides a holder, a gimbal spring held by the holder, and a gimbal spring.
Positioning part of the electrical component mounted at the center of the spring, and a positioning part interposed between the holder and the positioning part
In order to press the steel ball that swingably supports from below and the electrodes of the electric components mounted on this positioning portion against the lead pressed from above by the presser of the bonding head,
Push-up means for pushing up the positioning portion from below through the holder and the steel ball;
A load detecting element for detecting the load, and the load detecting element
The pressing force of the lifting means is controlled by the detection signal of the child.
Since the bonding unit is composed of a control unit and a control unit , even if the electrical components such as the board are inclined during bonding, the posture is corrected and all leads are evenly pressed to the electrodes evenly. it can.

[Brief description of the drawings]

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

FIG. 2 is a sectional view of a lead bonding apparatus according to an embodiment of the present invention.

FIG. 3 is a plan view of a gimbal spring used in a lead bonding apparatus according to an embodiment of the present invention.

4A is a side view of a main part during outer lead bonding according to one embodiment of the present invention; FIG. 4B is a side view of a main part during outer lead bonding according to one embodiment of the present invention;

[Explanation of symbols]

 2 Positioning part 12 Holder 17 Push-up means 20 Electrical component (substrate) 26 Bonding head 28 Presser (thermocompressor) 70 Electrode L Lead

Claims (1)

(57) [Claims] A holder and a holder held by the holder.
Between the gimbal spring and the positioning part of the electric component mounted at the center of the gimbal spring, and between the holder and the positioning part.
Steel that is interposed and supports the positioning part so that it can swing freely from below
The ball and the electrode of the electrical component mounted on this positioning part,
In order to press against the lead pressed from above against the pressing element of the bonding head, this positioning part should be
And pushing means for pushing up from below through the steel ball
And a load detecting element for detecting a load applied to the positioning portion.
And the push-up by the detection signal of the load detecting element.
And a control unit for controlling the pressing force by the means .