JP2000252326A - Bonding device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the detecting accuracy of pressurizing forces. SOLUTION: A bonding device is provided with the head of a chucking section 19 which moves in the Z-axis direction, holds electronic parts, and bonds the parts to a substrate by heating the parts while the head presses the parts against the substrate, a load cell 332 which is fixed to the head and, at the same time, measured the pressurizing force of the head, and a contact member 220 which comes into contact with the upper part of the load cell 332. The bonding device is also provided with a tension spring 330 which pulls up the head and, at the same time, presses the load cell 332 against the contact member 220 with a prescribed value.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a bonding apparatus for bonding a chip on 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, in the bonding apparatus, a pressing mechanism 10 is provided above a horizontal portion 1h of the inverted L-shaped base 1. In the pressurizing mechanism 10, a ball screw 14 is attached to a shaft of a motor 13 fixed to the horizontal portion 1h, and the ball screw 14 is screwed to the movable portion 15. Movable part 15
Is guided by a guide portion 16 provided on the vertical portion 1z of the gantry.

[0003] A suction part 19 is mounted in the movable part 15 via a load cell 18 provided on the bottom surface of a spring 17 engaged with the ball screw 14. The suction unit 19
The chip 21 is vacuum-sucked and the chip 21 is
3, a tip (head) 19a having a suction hole connected to a vacuum source, a heating unit 20 for heating the bump 21a of the chip 21, and a tip 19a.
Vacuum-adsorbs the chip 21 to form a substrate 23 on the mounting table 24.
Bonding.

That is, the chip 21 adsorbed on the tip 19a of the adsorbing section 19 is driven by the motor 13 in the pressurizing mechanism, is lowered via the movable section 15 by the ball screw 14, and is contact-pressed on the substrate 23 at a predetermined pressure. . Then, by driving the heating unit 20 to heat the chip 21 to a predetermined temperature, the bump 21 a is melted, and the chip 21 is placed on the substrate 23 by cooling.
Are to be bonded.

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

[0006]

However, in the above-mentioned conventional bonding apparatus, as shown in FIG.
A load P1 is urged by the pressing force of the spring 17 to the load cell 18 before descending from the load 9, and when the chip 21 comes into contact with the substrate 23 when the suction portion 19 descends (L on the X axis).
a), the load P1 and the own weight of the suction portion 19 are applied, and the pressing force of the suction portion 19 becomes P2. Therefore, it is inappropriate to press the bump 21a from zero finely. In particular, 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 must be replaced with another movable portion 15 having a low pressing force. was there.

Here, when the load P1 is biased in advance by the pressing force of the spring 17, the load cell 18 has an error of about ± 1% of the rated capacity in a region below the rating. Therefore, in a region extremely lower than the rated capacity, the detection error becomes large, so that 1/1
This is for detecting a load from 0 to 1/5 or more.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and can control a pressure value when a chip is suctioned by a suction portion and the chip is brought into contact with a substrate from a low region. An object of the present invention is to provide a bonding apparatus with high accuracy in detecting the pressing force by obtaining a certain pressure or more.

[0009]

According to a first aspect of the present invention, there is provided a bonding apparatus which moves in a Z-axis direction, holds an electronic component, and performs bonding by applying pressure and heat to a substrate. While being fixed, a pressing force detecting means for measuring the pressing force of the head, a contact member in contact with an upper portion of the pressing force detecting means, and a head being pulled up, and the pressing force detecting means being attached to the contact member. And a tension elastic member that presses at a predetermined value.

According to a second aspect of the present invention, there is provided a bonding apparatus including a pressure control mechanism for increasing a pressure applied to a head from substantially zero by controlling a force pressed against a contact member. It is.

According to a third aspect of the present invention, there is provided a pressure control mechanism for a bonding apparatus, wherein a pressing elastic member for pressing a contact member downward, a second elastic member for pulling up the contact member, and a Z-axis moving member. Accordingly, a pressing member for compressing the pressing-down elastic member is provided.

A bonding apparatus according to a fourth aspect of the present invention is characterized in that the bonding apparatus further comprises an elastic force adjusting means for adjusting the elastic force of the pressing elastic member or the second pulling elastic member.

A bonding apparatus according to a fifth aspect of the present invention includes a movable member which is disposed in parallel with the pressing-down elastic member and is movable so as to invalidate and validate the elastic force of the pressing-down elastic member. It is characterized by the following.

[0014] A bonding apparatus according to a sixth aspect of the present invention is characterized in that the bonding apparatus is provided with inclination adjusting means for adjusting the inclination of the head.

The bonding apparatus according to a seventh aspect of the present invention provides a gap between the upper surface of the pressing member and the lower surface of the movable member.
And control means for operating the tilting means.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 One embodiment of the present invention will be described with reference to FIGS. 1 to 3
, The bonding apparatus includes a pressing mechanism 100 provided above the inverted L-shaped base 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. A tilting mechanism 500 for tilting the suction unit 19 is provided. The pressing mechanism 100 has a ball screw 1 attached to a shaft of a motor 103 fixed to the horizontal portion 1h.
04 is attached, and the ball screw 104 is
It is screwed. The movable part 105 is a vertical part 1z of the gantry 1.
Is guided by the guide section 106 provided in the first section.

The pressurizing control mechanism 200 increases the pressing force applied to the tip (head) 19a of the suction unit 19 from substantially zero by the pressing force from the movable unit 105.
A tension spring 210 as an elastic member that pulls up the quadrangular prism-shaped contact member 220 is provided below the contact member 2.
An urging spring 212 as an elastic member for repelling the contact member 220 via a cylinder 250 fixed to the upper surface of the cylinder 20
And have been fixed. In addition, both ends of the tension spring 210 are fixed to horizontal columns 210a and 210b, respectively.

Load cell 332 as pressure detecting means
The pressing force applying mechanism for giving a predetermined pressing force, for example, P3 shown in FIG. 4, to the left side of the contact member 220 is provided with a tension spring 330 for lifting the load cell 332 and pressing the load cell 332 against the bottom surface of the contact member 220. I have. The contact member 220 has two grooves 2 vertically as shown in FIG.
20z is provided, and the sliding rod 22 is provided in the groove 220z.
2 and 222 are engaged with each other, and the lower ends of the sliding rods 222 and 222 are fixed to the upper part of the suction unit 19. The spring 33
0 are fixed to the horizontal columns 330a and 330b, respectively.

The elastic force control mechanism of the biasing spring 212 is such that an umbrella-shaped rod 250 a of a cylinder 250 fixed to the top surface of the contact member 220 is penetrated by the biasing spring 212.
The urging spring 212 is pressed by the lower surface of the tip of the rod 250a. Rod 2 of cylinder 250 operated by air
The elastic force of the urging spring 212 is made invalid by extending the 50a, and the elastic force of the urging spring 212 is made effective by contracting the rod 250a. The tip of the rod 250a has an umbrella shape because the tip of the rod 250a slides on the lower surface of the movable part 105 due to the inclination of the suction part 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 has a plate 401 mounted on the upper portion of the tension spring 210 via a horizontal support 210a. The tension spring is fixed at an appropriate position in two long holes 401a provided in the plate 401 with 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 between the plate 401 and the movable portion 105 with the bolt 403 inserted into the elongated hole 401a.

The tilt adjusting mechanism 500 for adjusting the tilt of the head 19a of the suction unit 19 is fixed to the side surface of the support frame 1 between the support frame 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 an arrow θ1 direction, a fulcrum shaft 506 fixed to the first block 504, and a rotation about the fulcrum shaft 506 in the arrow θ2 direction A second block 508 capable of supporting the guide 30 and configured so that the upper surface of the contact member 220 connected to the movable portion 105 by a spring or the like abuts on the upper surface of the horizontal portion of the substantially L-shaped stopper plate 520. Have been.

The operation of the bonding apparatus configured as described above will be described with reference to FIGS. First, loosening the screw of the bolt 403 from the movable part 105 so that the length L of the tension spring 210 becomes a predetermined value, and raising or lowering the plate 401 to adjust the length of the tension spring 210, Initial setting for fixing the bolt 403 to the elongated hole 401a is performed. Normally, the initial setting is unnecessary once for a considerable period.

Next, when the suction unit 19 operates the vacuum source to vacuum-suck the chip 21 and operates the cylinder 250, the rod 250a is extended until the elastic force of the urging spring 212 becomes invalid. Here, the reason why the urging spring 212 is invalidated is to suppress the vibration of the head 19a due to the movement. While the elastic force of the urging spring 212 is invalidated,
The motor 103 is rotated, and the driving unit 105 is lowered at a relatively high speed under the guidance of the guide unit 106 via the ball screw 104 to move the head 19 a of the suction unit 19 near the upper surface of the substrate 23.

In order to make the head portion 19a of the suction portion 19 parallel to the substrate 23, 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 brought into contact with the stopper plate. When it is raised until it contacts the lower surface of the horizontal portion 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,
By rotating the fulcrum shaft 502 and the fulcrum shaft 506 of the tilt adjustment mechanism 500, the first block 504 and the second block 50 are rotated.
8 to adjust the inclination of the head portion 19a.

After moving the suction section 19, the cylinder 250
Is released to make the elastic force of the urging spring 212 effective. Initially, as shown in FIG.
The biasing force of the tip spring 210 and the biasing force of the biasing spring 212 cancel each other and are almost zero. 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 tension spring 230 and initially have a 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
Since the tilt adjusting mechanism 500 is disposed between the movable section 105 and the reaction force at the time of pressurizing the bonding, the movable section 105 whose pressure is to be adjusted is received. Therefore, the tilt adjusting mechanism 500 is hardly affected by the pressing force. Therefore, a simple structure is sufficient.

[0027]

According to the first aspect of the invention, a head that moves in the Z-axis direction, holds an electronic component, and performs bonding by applying pressure and heat to a substrate, and a head fixed to the head and A pressure detection means for measuring the pressure of the head, a contact member that contacts the upper part of the pressure detection means, and a pull that pulls up the head and presses the pressure detection means against the contact member at a predetermined value. Since the pressing elastic member is provided, the pressing force is always applied to the pressing force detecting means by the elastic member for pulling, so that there is an effect that the detection accuracy can be improved.

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

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

According to the fourth aspect of the invention, in addition to the effect of the second aspect of the invention, there is provided an elastic force adjusting means for adjusting the elastic force of the pressing elastic member or the second pulling elastic member.
There is an effect that the reference position of the head is not easily changed.

According to the fifth aspect of the invention, in addition to the effects of the second aspect of the invention, in addition to being arranged in parallel with the elastic member for pushing down,
The movable movable member for invalidating and validating the elastic force of the pressing-down elastic member is provided, so that the head can be moved by invalidating the elastic force of the pressing-down elastic member. There is an effect that vibration of the head can be suppressed.

According to the sixth aspect, in addition to the effects of the first and second aspects, since the tilt adjusting means for adjusting the tilt of the head is provided, the head and the electronic component can be easily parallelized. is there.

According to the seventh aspect, in addition to the effect of the sixth aspect, since 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 inclination means is provided. There is an effect that the inclination means operates smoothly.

[Brief description of the drawings]

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

FIG. 2 is an overall configuration diagram showing a state in which a tilting mechanism is operated in the bonding apparatus of FIG. 1;

FIG. 3 is a side view as viewed from an arrow III in FIG. 1;

FIG. 4 is a pressure characteristic curve of the bonding apparatus shown in FIG. 4 is a characteristic curve according to the embodiment of the present invention.

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

FIG. 6 is a pressure 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 (tension elastic member), 200 pressure control mechanism, 212 depressing 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 tilt adjusting mechanism (tilt adjusting means).

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Kiyoharu Nagai 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Inside Mitsubishi Electric Corporation (72) Inventor Masamitsu Okamura 2-3-2 Marunouchi, Chiyoda-ku, Tokyo (72) Inventor Takuya Oga 2-3-2 Marunouchi, Chiyoda-ku, Tokyo F-term (reference) 5F044 BB01 BB06

Claims (7)

[Claims] 1. A head which moves in the Z-axis direction, holds an electronic component, and bonds to the substrate by pressing and heating the substrate, and a head fixed to the head and measuring a pressing force of the head. Pressure detecting means, a contact member that contacts the upper portion of the pressing force detecting means, and a tension elastic member that pulls up the head and presses the pressing force detecting means against the contact member at a predetermined value. A bonding apparatus characterized by the above-mentioned. 2. The bonding apparatus according to claim 1, further comprising: a pressure control mechanism configured to increase a pressing force of the head from substantially zero by controlling a force pressing the contact member. apparatus. 3. The pressing control mechanism includes: a pressing elastic member for pressing the contact member downward; a second pulling elastic member for pulling up the contact member; 3. A bonding device according to claim 2, further comprising: a pressing member for compressing the elastic member. 4. The bonding apparatus according to claim 2, further comprising: an elastic force adjusting means for adjusting an elastic force of the pressing-down elastic member or the second pulling elastic member. 5. A movable member which is disposed in parallel with the pressing-down elastic member and is movable such that the elastic force of the pressing-down elastic member is invalidated and made effective. 3. The bonding apparatus according to 2. 6. The bonding apparatus according to claim 1, further comprising: a tilt adjusting means for adjusting a tilt of the head. 7. The bonding apparatus according to claim 6, further comprising: control means for operating the tilt means after providing a gap between the upper surface of the pressing member and the lower surface of the movable member. .