JP3522001B2 - Chip bonding equipment - Google Patents

Description

Detailed Description of the Invention

[0001]

The present invention relates to a Chippubo for bonding a semiconductor chip to various circuit boards such as a liquid crystal substrate
And a binding device .

[0002]

2. Description of the Related Art Conventionally, chip bonding, in which a semiconductor chip is heated and pressure-bonded to various circuit boards such as liquid crystal boards, has been widely put to practical use.
Micron precision is required, and it is becoming even more precise. Therefore, in bonding, the parallelism of the chip suction holding surface (the lower end surface of the bonding tool) of the bonding tool with respect to the surface of the circuit board to be bonded must be maintained with high accuracy, and this is not maintained. Then, chip displacement occurs during the bonding, making it difficult to perform highly accurate bonding.
Therefore, many improvements regarding this point have been proposed.

That is, for example, Japanese Patent Laid-Open No. 6-13235.
In Japanese Patent Publication No. 7, the head bracket is moved downward by the Z table to bring the bonding tool close to the circuit board, and the piston rod of the cylinder mounted above the Z table is projected downward. Regarding the bonding head that applies a predetermined bonding pressure to the bonding tool, do not mount the bonding tool directly on the head bracket, but use an inclination adjustment device to adjust the inclination angle of the bonding tool with respect to the bonding surface of the circuit board. It is suggested to wear it. In addition, JP-A-5-2754
In the 88 publication, such an inclination adjusting device is also proposed.

[0004]

However, since these tilt adjusting devices are handled manually, the work is troublesome, and when the bonding pressure is applied, the lower end surface of the bonding tool is It had a defect that it was inclined. Therefore, in Japanese Patent Laid-Open No. 6-132357, there is further proposed an automatic tilt adjusting device using a displacement means such as a piezoelectric actuator.

However, the bonding head provided with such an automatic tilt adjusting device is
Although high technology is required to increase the device cost and high technology is required, there is a concern that parallelism with high accuracy cannot be maintained as expected.

The present invention has been invented in view of the above-mentioned drawbacks, and an object thereof is to apply pressure during bonding.
The adverse effect of the reaction force on the bonding pressure applied to the bonding tool by the means is mitigated ,
The parallelism of the chip suction holding surface (the lower end surface of the bonding tool) of the bonding tool with respect to the bonding surface of the circuit board can be kept constant, and highly accurate bonding, which has been difficult in the past , can be reliably performed. To do so.

[0007]

That is, a first chip bonding apparatus according to the present invention is a head bracket mounted so as to be able to move up and down via a Z table, and a circuit board by suction holding a semiconductor chip. In a chip bonding apparatus having a bonding tool for heating and pressure bonding to, and a cylinder for applying a bonding pressure to the bonding tool, the bonding tool can be slid on a tool vertical guide attached to the head bracket. A pressure transmission shaft is provided that is engaged with the head bracket and is suspended from the head bracket through an elastic body so as to be slidable through the head bracket. A reaction force receiving column is provided, and a block positioned above the Z table is provided between the pressure transmission shaft and the reaction force receiving column. A cylinder bracket, which is slidably engaged with the vertical guide for the racket and suspended from the reaction force receiving column via an elastic body, is provided, and the cylinder is transferred to the cylinder bracket by the pressure transmission. The bonding tool is provided so that a bonding pressure can be applied to the bonding tool via a shaft.

A second chip bonding apparatus according to the present invention is a head bracket mounted so as to be able to move up and down via a Z table, and a bonding tool for adsorbing and holding a semiconductor chip and performing thermocompression bonding on a circuit board. Have
In a chip bonding apparatus having a cylinder for applying a bonding pressure to the bonding tool, an XYθ table is attached to the head bracket.
Then , the tool bracket is attached to the θ table which constitutes the lower part of the XYθ table , and the bonding tool is slidably engaged with the vertical guide provided on the tool bracket and the elastic body is interposed. Suspended on the tool bracket, the head bracket, the XY
A pressure transmission shaft mounted so as to slide through the θ table and the tool bracket is provided, and a reaction force receiving column is provided above the pressure transmission shaft, and the pressure transmission shaft and the reaction force are provided. Between the receiving columns, slidably engaged with a vertical guide for the bracket located above the Z-table,
Also, a cylinder bracket suspended from the reaction force receiving column via an elastic body is provided, and the cylinder bracket can be provided with the cylinder and the bonding tool can be applied with a bonding pressure via the pressure transmission shaft. It is characterized by being provided in.

[0009]

In FIG. 1, when the chip slider 2 on which the semiconductor chip 1 is mounted is moved below the bonding tool 3, the bonding tool is suspended from the head bracket 5 via an elastic body (coil spring) 15. Three
Is moved downward together with the head bracket 5 by the drive of the Z table 6, and the semiconductor chip 1 on the slider 2 is moved.
Then, the Z table 6 is driven to return to the original upper original position.

On the other hand, the empty chip slider 2 is moved from the chip transfer position B to the chip supply position D by the slider transfer device 7. Then, by driving the Z table 6, the head bracket 5 is moved downward again, the bonding tool 3 is brought close to the circuit board on the lower boding stage (not shown), and then the piston rod 9 of the air cylinder 8 is moved. Is projected and the pressure transmission shaft 10 is pressed downward. Therefore, the bonding tool 3 is pushed downward by the pressure transmission shaft 10 and a predetermined bonding pressure is applied, so that the semiconductor chip 1 can be thermocompression bonded to the circuit board, that is, bonded.

At this time, the reaction force of the bonding pressure passes through the bonding tool 3, the pressure transmission shaft 10 and the piston rod 9 of the air cylinder 8 and the cylinder bracket 1
1, the bracket 11 slides, so that an excessive moment acts on the engagement portion between the cylinder bracket 11 and the vertical bracket guide 12 and the cooperation portion between the Z table 6 and the head bracket 5. Is prevented, and thus the chip suction holding surface (lower end surface) of the bonding tool 3 with respect to the bonding surface of the circuit board.
The parallelism can be kept constant and bonding can be performed with high precision.

When the bonding is completed, the piston rod 9 of the air cylinder 8 is retracted and moved to the upper origin position, and the Z table 6 is driven to move the head bracket 5 upward so that the bonding tool 3 is also moved upward. Returned to the origin position of.

In FIG. 1, the Z table 6 and the vertical bracket guide 12 which are the lifting control means are fixed to an apparatus frame (not shown) and the reaction force receiving means.
In a lower end (not shown) of the reaction force receiving post 13, front
Base whose serial device frame is fixed (Do has been shown
Fixed to have), i.e., the reaction force receiving post 13, Z table
Before the guide 6 and the vertical guide 12 for the bracket are fixed
It is installed separately from the device frame. Also,
Slider transfer device 7 is also fixed to the apparatus frame via a bracket, not shown. In addition, Z
The table 6 is provided with a screw shaft feed mechanism (not shown) that rotates the screw shaft by the servo motor 14 to feed the pitch, and the head bracket 5 is linked to this mechanism. Therefore, when the head bracket 5 is moved through such a mechanism, the bonding tool 3 and the pressure transmission shaft 10 mounted on the head bracket 5 are moved together.

Further, the bonding tool 3 can adsorb and hold the semiconductor chip 1 and has a built-in heater so that it can be quickly heated to a predetermined temperature by a pulse heater control device (not shown). An elastic body (coil bar) 15 is suspended by a pin 16 mounted on the head bracket 5 via the (coil bar) 15, that is, a pin 16 mounted on the head bracket 5 and a pin 17 mounted on the bonding tool 3. An elastic body (coil bar) 15 is also locked on the A side on the left side. Therefore, as shown in FIG. 2, the bonding tool 3 can be slid vertically by being guided by a pair of tool vertical guides 18 mounted on the head bracket 5.

On the other hand, the pressure transmission shaft 10 is supported by a bearing 19 fixed to the head bracket 3. The lower end of the pressure transmission shaft 10 is abutted against the upper end of the bonding tool 3 to prevent it from coming off, and the upper end thereof. The head bracket 3 is mounted so that it can be vertically slid through the head bracket 3 so as to project above the upper surface of the head bracket 3 for a certain length.

Therefore, by pressing the pressure transmission shaft 10 downward, the bonding tool 3 can be guided downward by the left and right tool vertical guides 18 and the pressing can be released. It can be returned to the original origin position above.

Next, the cylinder bracket 11 is slidably engaged with the vertical bracket guide 12 and is suspended from the reaction force receiving column 13 via the elastic body (coil bar) 20, that is, the cylinder. Pin 21 mounted on bracket 11 and pin 22 mounted on reaction force receiving column 13
An elastic body (coil bar) 20 is locked at the position.

A load cell 23 as a pressure detecting means is mounted on the upper surface side of the cylinder bracket 11, and an air cylinder 8 is mounted on the lower surface side thereof so that the piston rod 9 can be projected downward. The upper end of the load cell 23 is separated from the reaction force receiving column 13 at a predetermined interval, and the piston rod 9, the pressure transmission shaft 10, the bonding tool 3, and the load cell 23 are
They are located concentrically in the vertical direction, thus they
Piston rod 9 of air cylinder 8 which is a pressurizing means
It is located on the axis (of the pressurizing axis). Na
The piston rod 9 and the pressure transmission shaft 10 are usually separated from each other at regular intervals as shown in FIG . Then, the semiconductor chip 1 transferred by the chip slider 2 is suction-held by the bonding tool 3, and then the bonding tool 3 is moved downward to approach the circuit board on the lower bonding stage (not shown). After that, the piston rod 9 of the air cylinder 8 is projected and the pressure transmission shaft 10 is pressed downward, whereby the bonding tool 3 is pressed downward and a predetermined bonding pressure is applied, so that the semiconductor chip is attached to the circuit board. Can be thermocompression bonded, that is, bonded.

At this time, the bonding tool 3 is sucked at one end thereof through a pressure-resistant hose connected to an intake passage (not shown) provided at the lower end side of the tool 3 to obtain the above-mentioned product. The semiconductor chip 1 is sucked and held by sucking air from an intake hole formed in the lower end surface (chip suction holding surface) of the tool so as to communicate with the suction passage. The other end of the pressure resistant hose is connected to a vacuum pump (not shown). In addition, the semiconductor chip 1
The chip slider 2 on which is mounted is the bonding tool 3
When the Z table 6 is driven, the bonding tool 3 is moved downward together with the head bracket 5 and the lower end surface of the tool is lightly contacted with the semiconductor chip 1 on the slider 2. Then, the vacuum pump is driven, whereby the semiconductor chip 1 can be held by suction.

Subsequently, the bonding tool 3 capable of sucking and holding the semiconductor chip 1 is driven upward by the Z table 6 together with the head bracket 5 to the original upper position, that is,
Moved to the origin position. Further, the empty chip slider 2 is moved from the chip passing position B to the chip supply position D (not shown) by the slider transfer device 7. The transfer device 7 includes a screw shaft feed mechanism (not shown) that rotates the screw shaft by the servo motor 23 to feed the pitch, and the chip slider 2 is associated with this mechanism. Therefore, the tip slider 2 can be reciprocated while being kept horizontal.

That is, the chip slider 2 receives the semiconductor chip 1 at the chip supply position D and moves from there to the standby position C which is close to the bonding tool 3. In addition, the movement to the standby position C is performed by the bonding tool 3
Is moved down while bonding and
Moreover, when the bonding tool 3 is moved to the upper origin position after the bonding is completed, it is moved from the standby position C to the chip passing position B. Therefore, Bonding Tool 3
The semiconductor chip 1 can be supplied to the substrate more rapidly.

On the other hand, the bonding tool 3 which has suction-held the semiconductor chip 1 and has been moved to the upper origin position, then drives the Z table 6 to approach the circuit board on the lower boding stage (not shown). Confused,
Then, the bonding pressure is applied by the air cylinder 8. When the bonding tool 3 is moved to the upper origin position, the pressure transmission shaft 10
The upper end of the air cylinder 8 and the lower end of the piston rod 9 of the air cylinder 8 are separated at regular intervals.
The piston rod 9 is brought into contact with each other by the protrusion of the piston rod 9, and the pressure transmitting shaft 10 is moved downward to apply a predetermined bonding pressure to the bonding tool 3.

When a predetermined bonding pressure is applied to the bonding tool 3 in this way, the reaction force thereof passes through the bonding tool 3, the pressure transmission shaft 10 and the piston rod 9 of the air cylinder 8 and the cylinder bracket 11 Act on. Then, the bracket 11 is guided by the vertical bracket guide 12 and slid upward, and the load cell 2 on the upper surface side of the cylinder bracket 11 is guided.
3 is brought into contact with the reaction force receiving column 23.

Therefore, the engaging portion of the cylinder bracket 11 and the vertical guide 12 for the bracket, and the Z table 6
It is possible to prevent an excessive moment from acting on the cooperation portion between the head bracket 5 and the head bracket 5, and thus the parallelism of the chip suction holding surface (the lower end surface of the bonding tool) of the bonding tool 3 with respect to the bonding surface of the circuit board. It can be kept constant, and high-accuracy bonding, which is difficult in the conventional bonding head, can be reliably performed. That is, 10 μ or less,
In particular, thermocompression bonding can be performed with an accuracy of 5 μ or less.

At this time, if the cylinder bracket 11 tries to move excessively upward, the load cell 23 can detect the reaction force and keep the bonding pressure constant.
Since the cell 23 can display the pressure and control the pressure, the bonding condition can be stabilized, and not only the one-step press but also the multi-step press (step press). Since it is also possible to select stable bonding conditions, and since the air cylinder 8 is also moved up and down, it is possible to measure the pressing force with the load cell 23.

After the bonding is completed, the piston rod 9 of the air cylinder 8 is retracted and moved to the upper origin position, and the suction by the vacuum pump is stopped and the Z table 6 is driven to bond the tool. 3 is moved to the upper origin position. In this way, you can bond one after another. When the pressure transmission shaft 10 is short, the same effect can be obtained by connecting the shaft 10 to the piston rod 9.

The example in which the bonding tool 3 is directly attached to the head bracket 5 has been described above. However, such a bonding head can be used before bonding.
Suitable for generally small circuit board bonding, in which the circuit board on the lower bonding stage (not shown) and the semiconductor chip 1 held by the bonding tool 3 are precisely aligned by finely moving the bonding stage. Is.

Next, an example in which a bonding tool is indirectly attached to the head bracket 5 will be described. In FIG. 3, the XY table 30a constituting the upper portion of the XYθ table 30 is fixed to the head bracket 5. A tool bracket 31 is fixed to a θ table 30b that constitutes a lower part of the XYθ table 30, and the bonding tool 3 is attached to the tool bracket 31.
2 is installed.

That is, the bonding tool 32 can adsorb and hold the semiconductor chip 1 and has a built-in heater, like the above-described bonding tool 3 shown in FIG. 1, and can be quickly operated by a pulse heater control device (not shown). The tool bracket 3 is configured to be heated to a predetermined temperature via a pair of elastic bodies (coil springs) 15.
1. An elastic body (coil spring) 15 is locked to the pin 16 attached to the tool bracket 31, that is, the pin 16 attached to the tool bracket 31 and the pin 17 attached to the bonding tool 32 (similarly to the opposite side not shown). Locked).

Although the bonding tool 32 forms a guide portion 32a, this guide portion 32a is a hole-shaped vertical guide 31 formed on the tool bracket 31.
It is slidably inserted in a. Therefore, when the head bracket 5 is moved downward by driving the Z table 6, the bonding tool 3 follows the tool bracket 31 that is moved downward integrally with the bracket 5.
2 also moves in the same direction, and conversely, when the head bracket 5 moves upward, the bonding tool 32 also moves in the same direction.

Further, the pressure transmission shaft 10 has a head bracket 5 and an XYθ table 30 so that the lower end thereof is brought into contact with the bonding tool 32 to prevent the pressure transmission shaft 10 from coming off, and the upper end thereof is projected onto the upper surface of the head bracket 5. It is mounted so as to be able to slide through the tool bracket 31.

With this bonding head, as in the above-described bonding head shown in FIG. 1, the semiconductor chip 1 transferred by the chip slider 2 is adsorbed and held by the bonding tool 3 and then, After moving the tool 3 downward to bring it closer to a circuit board on a lower boding stage (not shown), the piston rod 9 of the air cylinder 8 is projected to press the pressure transmission shaft 10 downward. As a result, the bonding tool 3 is pushed downward and a predetermined bonding pressure is applied, so that the semiconductor chip 1 can be thermocompression bonded, that is, bonded to the circuit board.

At that time, the engaging portion between the cylinder bracket 11 and the vertical bracket guide 12 and the Z table 6
It is possible to prevent an excessive moment from acting on the joint portion between the head bracket 5 and the head bracket 5, and thus the parallelism of the chip suction holding surface (the lower end surface of the bonding tool) of the bonding tool 32 to the bonding surface of the circuit board. Can be kept constant, and high-accuracy bonding, which was difficult in the conventional bonding head, can be reliably performed.

Since the XYθ table 30 is attached, the circuit board on the lower bonding stage (not shown) and the semiconductor chip 1 held by the bonding tool 32 by suction are precisely aligned prior to bonding. Can be performed by finely moving the bonding tool 32, which is suitable for bonding to a large and heavy circuit board.

Although the embodiments according to the present invention have been described above, in the present invention, the circuit board to be bonded is not limited to a transparent substrate such as a liquid crystal substrate, and may be another opaque circuit board. Good. The vertical guide of the tool bracket may be, for example, a concave type or a convex type other than the hole type, and the guide portion of the bonding tool engaged with this may correspond to the type of the vertical guide. A predetermined type is appropriately selected (for example, when the vertical guide is a convex type, a concave type is selected). Further, although it is preferable to mount the load cell, it is possible to omit the load cell. It can be mounted in an appropriate mode as needed so that it is lightly abutted even when it is not.

[0036]

[Effect of the Invention] As described above, according to the present invention, upon bonding, to mitigate its adverse effects due to the reaction force against the bonding pressure applied to depending on the bonding tool cylinder, it has been, bonding tool for bonding surface of the circuit board The parallelism of the chip suction holding surface (lower end surface of the bonding tool) can be kept constant, and high-accuracy bonding, which has been difficult in the past, can be reliably performed.

[Brief description of drawings]

FIG. 1 is a perspective view of a bonding head.

FIG. 2 is a vertical sectional view of a head bracket portion of FIG.

FIG. 3 is a perspective view of another bonding head.

[Explanation of symbols]

1 semiconductor chip 2 chip slider 3 Bonding tool 5 head bracket 6 Z table 7 Slider transfer device 8 air cylinders 9 Piston rod 10 Pressure transmission shaft 11 Cylinder bracket 12 Vertical guide for bracket 13 Reaction force receiving column 15 Elastic body (coil bar) 16 pin 17 pin Vertical guide for 18 tools 20 Elastic body (coil spring) 21 pin 22 pin 23 load cell 30 XYθ table 31 tool bracket 31a Vertical guide 32 Bonding tool 32a guide part

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Satoru Sakaguchi               Toray, 1-41 Oe, Otsu City, Shiga Prefecture               Engineering Co., Ltd. (72) Inventor Yasuo Hashimoto               Toray, 1-41 Oe, Otsu City, Shiga Prefecture               Engineering Co., Ltd.

Claims (3)

(57) [Claims] And 1. A head bracket mounted so as to move up and down through the Z table, a bonding tool for thermocompression bonding a semiconductor chip to a circuit board held suction Yes
Then, in a chip bonding apparatus having a cylinder for applying a bonding pressure to the bonding tool, the bonding tool is slidably engaged with a tool vertical guide attached to the head bracket,
Also, it is suspended from the head bracket through an elastic body and attached so that it can slide through the head bracket.
For a bracket positioned above the Z table between the pressure transmission shaft and the reaction force receiving support column, and a reaction force receiving support column is provided above the pressure transmission shaft. A cylinder bracket slidably engaged with the vertical guide and suspended from the reaction force receiving column through an elastic body is provided, and the cylinder and the pressure transmitting shaft are provided on the cylinder bracket. A chip bonding apparatus provided so that a bonding pressure can be applied to the bonding tool via the bonding tool. 2. A head bracket mounted so as to move up and down through the Z table, a bonding tool for thermocompression bonding a semiconductor chip to a circuit board held suction Yes
In a chip bonding apparatus having a cylinder that applies a bonding pressure to the bonding tool, an XYθ table is attached to the head bracket, and a tool bracket is attached to a θ table that constitutes a lower portion of the XYθ table. The tool is slidably engaged with a vertical guide provided on the tool bracket and is suspended on the tool bracket through an elastic body, and penetrates the head bracket, the XYθ table and the tool bracket. the loaded <br/> pressurized pressure transmission shaft so as to slide is provided, the reaction force receiving posts provided above the pressurized pressure transmission shaft, between the pressurizing pressure transmission shaft and the reaction force receiving posts Te An elastic body slidably engaged with a vertical bracket guide positioned above the Z-table A cylinder bracket suspended from the reaction force receiving column is provided, and the cylinder bracket is provided with the cylinder so as to apply a bonding pressure to the bonding tool via the pressure transmission shaft. Characteristic chip bonding equipment. 3. The cylinder bracket is provided with a load cell that faces the reaction force receiving column and that detects a reaction force when the cylinder bracket attempts to move upward. The described chip bonding apparatus.