JP3409725B2 - 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 an improvement of a bonding apparatus for bonding a chip onto a substrate by a flip chip method.

[0002]

2. Description of the Related Art A conventional bonding apparatus will be described with reference to FIG. In FIG. 5, the bonding apparatus is provided with a pressing mechanism 10 above the horizontal portion 1h of the inverted L-shaped mount 1. In the pressure mechanism 10, a ball screw 14 is attached to the shaft of a motor 13 fixed to the horizontal portion 1h, and the ball screw 14 is screwed with a movable portion 15. Movable part 15
Is guided by a guide portion 16 provided on the vertical portion 1z of the gantry.

Inside the movable portion 15, a suction portion 19 is attached via a load cell 18 provided on the bottom surface of a spring 17 engaged with the ball screw 14. The suction part 19 is
The chip 21 is vacuum-sucked and the chip 21 is attached to the substrate 2
3, the tip (head) 19a has a suction hole connected to a vacuum source, and the heating section 20 for heating the bump 21a of the chip 21 is provided.
Sucks the chip 21 under vacuum, and places the substrate 23 on the mounting table 24.
Bonded to.

That is, the chip 21 sucked on the tip 19a of the suction portion 19 is driven by the motor 13 in the pressing mechanism to be lowered by the ball screw 14 via the movable portion 15 and contact-pressed onto the substrate 23 at a predetermined pressure. . Then, by driving the heating unit 20 to heat it to a predetermined temperature, the bumps 21a are melted and the chips 21 are placed on the substrate 23 by cooling.
Is to be bonded.

In this case, the pressure of the chip 21 on the substrate 23 is added to the pressure of the spring 17, and the load cell 1
While detecting the load received by the suction unit 19 from the suction unit 8, the movable unit 15 is lowered so as to reach the set value while controlling the pressing load by the feedback control based on the detected value.

[0006]

However, in the above-mentioned conventional bonding apparatus, as shown in FIG.
The load P1 is urged by the pressing force of the spring 17 to the load cell 18 before descending 9, and when the suction portion 19 descends and the chip 21 comes into contact with the substrate 23 (L of the X axis).
a) Since the load P1 and the self-weight of the suction portion 19 are added, the pressure of the suction portion 19 becomes P2, which is inappropriate for finely pressing the bump 21a from zero. Especially when used for flip chips, the number of bumps 21a,
Depending on the forming material, the pressing force P value is in a wide range of 10 to 500 N. Therefore, when a low pressing force is required, it is necessary to replace it with another movable part 15 having a low pressing force. was there.

Here, the load P1 is pre-biased by the pressing force of the spring 17 because the load cell 18 has an error of about ± 1% of the rated capacity in a region below the rated value. Therefore, the detection error becomes large in the area that is extremely lower than the rated capacity.
This is because the load from 0 to 1/5 or more is detected.

The present invention has been made in order to solve the above problems, and it is possible to control a pressing force value when a chip is adsorbed by an adsorbing portion and the chip comes into contact with a substrate from a low region, and moreover, a load cell. It is an object of the present invention to provide a bonding apparatus having a high detection accuracy of the applied pressure by obtaining a predetermined value or more for the pressurization.

[0009]

A bonding apparatus according to a first aspect of the present invention includes a head which moves in the Z-axis direction, holds an electronic component and pressurizes and heats a substrate to perform bonding, and While being fixed, a pressing force detecting means for measuring the pressing force of the head, a contact member contacting the upper portion of the pressing force detecting means, and pulling up the head, the pressing force detecting means to the contact member. And a pulling elastic member that presses at a predetermined value.

A bonding apparatus according to a second aspect of the present invention includes a pressure control mechanism for increasing the pressure applied to the head from substantially zero by controlling the force applied to the contact member. Is.

A pressure control mechanism of a bonding apparatus according to a third aspect of the present invention includes a push-down elastic member that pushes down the contact member, a second pulling elastic member that pulls up the contact member, and moves in the Z-axis direction. Thus, the pressing member for compressing the elastic member for pressing down is provided.

A bonding apparatus according to a fourth aspect of the invention is characterized by including elastic force adjusting means for adjusting the elastic force of the pushing down elastic member or the second pulling elastic member.

A bonding apparatus according to a fifth aspect of the present invention includes a movable movable member which is disposed in parallel with the pressing down elastic member and which nullifies and validates the elastic force of the pressing down elastic member. It is characterized by.

A bonding apparatus according to a sixth aspect of the invention is characterized by including inclination adjusting means capable of adjusting the inclination of the head.

In the bonding apparatus according to the seventh aspect of the invention, a gap is provided between the upper surface of the pressing member and the lower surface of the movable member,
The control means for operating the tilting means is provided.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiment 1. An embodiment of the present invention will be described with reference to FIGS. 1 to 3
In the bonding apparatus, the bonding apparatus includes a pressing mechanism 100 provided above the inverted L-shaped mount 1, and a pressing control mechanism for controlling the pressing force applied from the pressing mechanism 100 to the tip of the suction unit 19. 200 and an inclining mechanism 500 for inclining the suction portion 19 are provided. The pressurizing mechanism 100 includes a ball screw 1 mounted on a shaft of a motor 103 fixed to a horizontal portion 1h.
04 is attached and the ball screw 104 is attached to the movable portion 105.
Is screwed together. The movable part 105 is the vertical part 1z of the gantry 1.
It is guided by the guide portion 106 provided in the.

The pressurizing control mechanism 200 increases the pressing force applied to the tip portion (head) 19a of the suction part 19 from almost zero by the pressure applied from the movable part 105.
A tension spring 210 as an elastic member for pulling up the square pole contact member 220 and a contact member
A biasing spring 212 as an elastic member that repels the contact member 220 via a cylinder 250 fixed to the upper surface of
And are fixed. Both ends of the tension spring 210 are fixed to the horizontal columns 210a and 210b, respectively.

Load cell 332 as a pressing force detecting means
In the pressing force applying mechanism that applies a predetermined pressing force, for example, P3 shown in FIG. 4, to the left side surface of the contact member 220, a tension spring 330 that pulls up the load cell 332 and presses the load cell 332 against the bottom surface of the contact member 220 is provided. There is. In addition, the contact member 220 has two grooves 2 vertically arranged as shown in FIG.
20z is provided, and the sliding rod 22 is provided in the groove 220z.
2, 222 are engaged with each other, and the lower end portions of the sliding rods 222, 222 are fixed to the upper portion of the suction portion 19. The spring 33
Both ends of 0 are fixed to horizontal columns 330a and 330b, respectively.

In the elastic force control mechanism of the urging spring 212, the umbrella-shaped rod 250a of the cylinder 250 fixed to the top surface of the contact member 220 penetrates the urging spring 212.
The biasing spring 212 is pressed by the lower surface of the tip of the rod 250a. Rod 2 of cylinder 250 operated by air
By extending 50a, the elastic force of the urging spring 212 is made ineffective, and by contracting the rod 250a, the elastic force of the urging spring 212 is made effective. The tip of the rod 250a has an umbrella shape because the tip of the rod 250a and the lower surface of the movable portion 105 slide due to the inclination of the suction portion 19, so that the frictional force is reduced.

The tension spring length adjusting mechanism 400 is provided to adjust the spring length of the tension spring 210 to a predetermined value. The tension spring 210 is attached to the plate 401 via the horizontal column 210a above the tension spring 210. The tension spring length is fixed and fixed to the appropriate positions of the two long holes 401a provided in the plate 401 by two bolts 403 so that the tension spring length can be set to a predetermined value. That is, the spring length of the tension spring 210 can be adjusted by adjusting the fixed position of the plate 401 and the movable portion 105 with the bolt 403 inserted into the long hole 401a.

An inclination adjusting mechanism 500 capable of adjusting the inclination of the head 19a of the suction unit 19 is fixed to the side surface of the support base 1 between the support base 1 and the guide 30 provided on the side surface of the suction unit 19. A fulcrum shaft 502, a first block 504 rotatable about the fulcrum shaft 502 in the arrow θ1 direction, a fulcrum shaft 506 fixed to the first block 504, and a rotation around the fulcrum shaft 506 in the arrow θ2 direction. A second block 508 that supports the guide 30 is provided, and the upper surface of the contact member 220 connected to the movable portion 105 by a spring or the like contacts the upper surface of the horizontal portion of the substantially L-shaped stopper plate 520. Has been done.

The operation of the bonding apparatus configured as described above will be described with reference to FIGS. 1 to 4. First, the screwing of the bolt 403 is loosened from the movable portion 105 so that the length L of the tension spring 210 becomes a predetermined value, and the plate 401 is moved up or down to adjust the length of the tension spring 210. Initial setting is performed to fix the bolt 403 to the long hole 401a. If the initial setting is normally performed once, it is unnecessary for a considerable period of time.

Next, when the vacuum source is operated and the suction part 19 vacuum-sucks the chip 21 to operate the cylinder 250, the rod 250a is extended until the elastic force of the biasing spring 212 becomes invalid. Here, the urging spring 212 is made ineffective in order to suppress the vibration of the head 19a due to the movement. With the elastic force of the urging spring 212 disabled,
The motor 103 is rotated, and the drive unit 105 is lowered at a relatively high speed by the guide of the guide unit 106 via the ball screw 104 to move the head 19a of the suction unit 19 to the vicinity of the upper surface of the substrate 23.

In order to make the head portion 19a of the suction portion 19 and the substrate 23 parallel to each other, the motor 103 is rotated and the movable portion 105 is guided by the guide portion 106 via the ball screw 104 so that the upper surface of the contact member 220 is a stopper plate. When it is raised until it contacts the lower surface of the horizontal portion of 520, the gap between the upper surface of the rod 250a of the cylinder 250 and the lower surface of the movable portion 105 becomes Z as shown in FIG. In such a state,
The fulcrum shaft 502 and the fulcrum shaft 506 of the tilt adjusting mechanism 500 are rotated to rotate the first block 504 and the second block 50.
8 is operated to adjust the inclination of the head portion 19a.

After moving the suction unit 19, the cylinder 250
The air being supplied to is released and the elastic force of the biasing spring 212 becomes effective. Initially, as shown in FIG.
The urging force on the tip spring 210 and the urging force of the urging spring 212 cancel each other out and is almost zero, but it is linear from the point La at which the bump 21a of the chip 21 and the head 19a come into contact with each other. The pressing force of the bump 21a and the load cell 332 increases. On the other hand, the load cell 332
The contact member 220 and the pressing force are pulled up by the extension spring 230 and initially have the pressing value of P3. The pressing value P3 is 1/1 of the rated capacity of the load cell 332.
If it is set to about 0 to 1/5, the detection accuracy is improved.

In the above embodiment, the gantry 1 and the guide 30 are used.
Since the tilt adjustment mechanism 500 is disposed between the tilt adjustment mechanism 500 and the movable portion 105, the reaction force during bonding pressurization is received by the movable portion 105 whose pressure is to be adjusted. It has a simple structure.

[0027]

According to the first aspect of the present invention, a head which moves in the Z-axis direction, holds an electronic component and presses and heats it on a substrate for bonding, is fixed to this head, and Pressurizing force detecting means for measuring the pressurizing force of the head, a contact member contacting the upper portion of the pressurizing force detecting means, and pulling for pulling up the head and pressing the pressurizing force detecting means against the contact member at a predetermined value. Since the pressing elastic force member is always provided with the pressing force by the pulling elastic member, the detection accuracy can be improved.

According to the second aspect of the invention, in addition to the effect of the first aspect of the invention, the pressure control mechanism for increasing the pressure of the head from almost zero by controlling the force pressing the contact member is provided. Therefore, the pressing force of the head can be smoothly increased.

According to the third invention, in addition to the effect of the first invention, the pressurizing control mechanism includes a pressing elastic member for pressing the contact member downward and a second elastic member for pulling up the pressing member. , By moving in the Z-axis direction,
Since the pressing member for compressing the pressing elastic member is provided, there is an effect that the pressing force of the head can be smoothly increased with a simple structure.

According to the fourth invention, in addition to the effect of the second invention, the elastic force adjusting means for adjusting the elastic force of the elastic member for pushing down or the elastic member for pulling the second member is provided.
The effect is that the reference position of the head does not easily change.

According to the fifth invention, in addition to the effect of the second invention, it is arranged in parallel with the elastic member for pushing down, and
Since the movable movable member for invalidating and validating the elastic force of the pushing down elastic member is provided, the elastic force of the pushing down elastic member can be nullified and the head can be moved, so that the pushing down elastic member vibrates. There is an effect that the vibration of the head can be suppressed.

According to the sixth aspect of the invention, in addition to the effect of the first or second aspect of the invention, since the tilt adjusting means for adjusting the tilt of the head is provided, the effect that the head and the electronic component can be parallel easily is obtained. is there.

According to the seventh aspect of the invention, in addition to the effect of the sixth aspect of the invention, the control means for activating the tilting means after providing the gap between the upper surface of the pressing member and the lower surface of the movable member is provided. There is an effect that the tilting means operates smoothly.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of a bonding apparatus showing an embodiment of the present invention.

2 is an overall configuration diagram showing a state in which a tilting mechanism is operated in the bonding apparatus of FIG.

FIG. 3 is a side view seen from an arrow III in FIG.

4 is a pressurizing characteristic curve of the bonding apparatus shown in FIG. It is a characteristic curve of one embodiment of the present invention.

FIG. 5 is an overall configuration diagram showing a conventional bonding device.

FIG. 6 is a pressurization characteristic curve of a conventional bonding apparatus.

[Explanation of symbols]

19a head, 210 second tension spring (second tension elastic member), 220 contact member, 330 tension spring (tensile elastic member), 200 pressure control mechanism, 212 press down elastic member (biasing spring), 250
a rod (movable member), 332 load cell (pressurizing force detecting means), 400 elastic force adjusting mechanism (elastic force adjusting means), 500 inclination adjusting mechanism (inclination adjusting means).

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masamitsu Okamura 2-3-3 Marunouchi, Chiyoda-ku, Tokyo Mitsubishi Electric Corporation (72) Inventor Takuya Oga 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Mitsubishi (56) References JP-A-8-288338 (JP, A) JP-A-9-199545 (JP, A) JP-A-11-145202 (JP, A) JP-A-11-145203 (JP , A) (58) Fields investigated (Int.Cl. ⁷ , DB name) H01L 21/60 H01L 21/52 H05K 3/32 H05K 13/04

Claims (7)

(57) [Claims] 1. A head, which moves in the Z-axis direction, holds an electronic component, and presses and heats a substrate to bond the head, and a head fixed to the head and measuring the pressure of the head. A pressure detecting means; a contact member that comes into contact with the upper portion of the pressing force detecting means; and a pulling elastic member that pulls up the head and presses the pressing force detecting means against the contact member at a predetermined value. A bonding device characterized by the above. 2. The bonding according to claim 1, further comprising a pressurizing control mechanism for increasing the pressure applied to the head from substantially zero by controlling the force applied to the contact member. apparatus. 3. A pressurizing control mechanism comprises: a push-down elastic member that pushes down the contact member downward; a second pulling elastic member that pulls up the contact member; and a push-down elastic member that moves in the Z-axis direction. The bonding device according to claim 2, further comprising: a pressing member that compresses the elastic member for use. 4. The bonding apparatus according to claim 2, further comprising elastic force adjusting means for adjusting an elastic force of the pushing down elastic member or the second pulling elastic member. 5. A movable member, which is arranged in parallel with the elastic member for pushing down and which is capable of invalidating and validating the elastic force of the elastic member for pushing down. The bonding apparatus according to 2. 6. The bonding apparatus according to claim 1, further comprising an inclination adjusting unit capable of adjusting the inclination of the head. 7. The bonding apparatus according to claim 6, further comprising: a control unit that operates the tilting unit after providing a gap between the upper surface of the pressing member and the lower surface of the movable member. .