JP3303705B2 - Thermocompression bonding equipment for electronic components with bumps - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermocompression bonding apparatus for electronic components with bumps.

[0002]

2. Description of the Related Art An electronic component with bumps has a large number of bumps on its lower surface, and all of these bumps are evenly pressed on electrodes of a circuit pattern on the substrate to be correctly mounted on the substrate.

However, in general, bumps of electronic parts with bumps vary in height. If a soft and flexible substrate is used, it is possible to absorb the variation in bumps depending on the degree of deflection of the substrate. Some substrates are hard and hard to bend, such as glass epoxy substrates, and the deflection of the substrate often cannot absorb variations.

[0004] For this reason, in order to mount the electronic component with bumps correctly as described above, it is necessary to press-fit all the bumps while pressing them against the electrodes of the substrate with an equal force. However, in practice, uneven pressure is likely to occur due to uneven bias of the bumps due to unevenness in the height of the bumps or unevenness in the parallelism between the lower surface of the suction tool for performing the pressing and the upper surface of the substrate. For this reason, a tilt mechanism that uses a spherical bearing in the pressure bonding head is provided to reduce uneven pressure bonding, and the lower surface of the suction tool (accurately, the arrangement surface of bumps) is aligned with the upper surface of the substrate to absorb variations in parallelism. Things are known.

[0005]

However, in a conventional crimping apparatus using a crimping head, when a suction tool holds an electronic component with bumps and joins the electronic component with bumps to a substrate,
The tilting mechanism causes the suction tool to rotate in the θ direction, which causes a problem in that the relative positions of the electrodes and the bumps on the substrate are deviated. In particular, when a flip chip in which bumps are formed on electrodes of a semiconductor IC is mounted on a substrate, high precision mounting is required in addition to less pressure unevenness, and this problem is particularly remarkable.

[0006] The present invention, bumps can without unevenness thermocompression bonding, moreover an object to provide a thermocompression bonding apparatus for electronic components with bumps capable alignment with high accuracy on the substrate.

[0007]

The present invention SUMMARY OF] causes the landing electronic parts bumped bump to an electrode on the substrate placed on the table, heat of the electronic component with bumps thermocompression bonding the bump to the electrode by crimping head a crimping device, the crimping head, a first fixed block its lower surface is Y arc surface, the top surface due to contact with the thermocompression bonding in the Y arcuate surface
A first movable block to rotate along the Y arcuate surface Te,
It is provided below the first movable block, and its lower surface is X
It includes a second fixed block is an arc surface, a second movable block whose upper surface is rotated along the X arcuate surface by contact with said heat bonding to the X arcuate surface, on the lower side of the second movable block Heat insulation unit and heater with heater
Block and suction tool for vacuum suction of electronic components with bumps
Was installed .

[0008]

According to the present invention having the above structure, even if the substrate and the bump are not parallel, the first movable block and the second movable block are rotated along the Y-arc surface and the X-arc surface. The electronic components with bumps sucked by the suction tool are tilted, and the board and the bumps can be made parallel by making them conform to the board, and all the bumps are evenly pressed against the electrodes of the board and mounted. Defects can be eliminated.

Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram of a crimping apparatus for an electronic component with bumps according to an embodiment of the present invention. As shown in FIG. 1, a substrate 1 is a substrate holder 2 on a table 3.
Be placed on The table 3 is a movable table that horizontally moves the substrate 1 in the X direction or the Y direction and positions it at a predetermined position. On the substrate holder 2, a surface plate 4 adjusted so as to have a sufficient level is installed.

Above the substrate holder 2, there is provided a Z table 5 for raising and lowering the elevating plate 6 in the Z direction by a Z motor 7, and a head holder 8 is fixed to the front surface of the elevating plate 6. The load cell 9 measures a load acting on the head holder 8 and outputs a load signal to the control unit C. This load signal is used for later-described detection of bump landing.

The head holder 8 includes
A header 11 having a pull stud bolt 12 is mounted, and the pressure bonding head 10 moves up and down integrally with the lifting plate 6. Compressed air discharged from the air supply source 13 is supplied to the pressure bonding head 10 through a pipe 14. This compressed air is blown out at a boundary between a Y-arc surface and an X-arc surface described later. The detailed structure of the pressure bonding head 10 will be described later.

A recognition device 15 is provided beside the pressure bonding head 10 and has a camera section 17 which moves back and forth in the direction of arrow N1 by a moving shaft 16 and observes the upper and lower sides. The camera unit 17 observes the bumps of the electronic component P with bumps and the circuit pattern of the substrate 1 right below the electronic component P with bumps sucked by the pressure bonding head 10 as shown by the broken line in FIG. .

Next, referring to FIG. 2 and FIG.
The structure of 0 will be described. A first fixing block 18 is fixed to a lower portion of the header 11 by a bolt B1. The lower surface of the first fixed block 18 is a Y-arc surface 19 that curves in the Y direction. The arc-shaped upper surface of the first movable block 20 is in contact with the Y-arc surface 19 of the first fixed block 18, and the first movable block 20 rotates along the Y-arc surface 19 (arrow in FIG. 2). M1). A second fixed block 21 is fixed to a lower portion of the first movable block 20 by a bolt B2. The lower surface of the second fixed block 21
It is an X-arc surface 22 that curves in the X direction. The arc-shaped upper surface of the second movable block 23 is in contact with the X arc surface 22, and the second movable block 23 rotates along the X arc surface 22 (see the arrow M2 in FIG. 3).

As will be described later, the electronic component P with bumps is vacuum-sucked on the lower surface of the suction tool 36.
The electronic component P with bumps vacuum-sucked on the Y-shaped surface 6
The curvatures of the Y-arc surface 19 and the X-arc surface 22 are determined so as to be located at the centers O1 and O2 of the X-arc surface 22.
Thus, even when the tilt operation in the M1 direction or the M2 direction is performed, the position of the electronic component with bumps P is not changed, so that the electronic component with bumps P can be pressed to the correct position on the substrate 1.

Here, the first movable block 20 is regulated by the X guide plate 24 (FIG. 3) so as not to be shifted in the X direction and the θ direction with respect to the first fixed block 18, and the second movable block 23 is By the Y guide plate 25 (FIG. 2), the second
It is regulated so as not to shift in the Y direction and the θ direction with respect to the fixed block 21. Therefore, the first movable block 20 rotates only along the XZ plane, and the second movable block 23 rotates along the YZ plane orthogonal to the XZ plane. This prevents the first movable block 20 and the second movable block 23 from being unnecessarily displaced in the XY directions and rotating in the θ direction during the tilt operation, and does not cause the displacement of the electronic component with bumps due to the tilt operation. Like that. The header 11, the first fixed block 18, the first movable block 20, the second fixed block 21, and the second movable block 23 are formed with through-holes coaxial with the pull stud bolts 12, and are drawn in the through-holes. The upper bar 27 is slidably inserted.

The lower end of the through hole is enlarged in the second movable block 23 to form a ball seat 26, and the ball seat 26 is provided with a ball 28 provided at the lower end of a pull-up rod 27. Is located. The upper end of the pull-up bar 27 is urged upward by a spring 29. Accordingly, the arc-shaped upper surface of the first movable block 20 is firmly pressed against the Y-arc surface 19 by the spring force of the spring 29, and the second
The arc-shaped upper surface of the movable block 23 is firmly pressed against the X-arc surface 22.

Here, the compressed air supplied from the pipe 14 can be discharged to the Y-arc surface 19 and the X-arc surface 22. A gap is formed. At this time, the first movable block 20 is allowed to tilt (rotate) in the direction of arrow M1 with respect to the first fixed block 18, and the second movable block 23 is tilted in the direction of arrow M2 with respect to the second fixed block 21. forgiven. Conversely, when the discharge is stopped, the spring force of the ball 28 causes
The two-way tilt described above is prohibited, and a tilt lock state is set. As described above, the pull-up bar 27, the ball 28, and the spring 29 are locking means for locking the rotation of the first movable block 20 with respect to the Y-arc surface 19 and the rotation of the second movable block 23 with respect to the X-arc surface 22. The air supply source 13 and the piping 14 are switching means for switching between tilt lock and tilt lock release by switching between supply and stop of supply of compressed air.

As the locking means and the switching means, magnetic means and the like can be applied. That is, the first fixed block 1
8. The second fixed block 21 is formed by an electromagnet,
The movable block 20 and the second movable block 23 are formed of a magnetic material, and the first movable block 20 is attracted to the first fixed block 18 by generating a magnetic force. The lock may be released by attracting and locking the magnetic force and reducing the magnetic force.

At the lower part of the second movable block 23, an intermediate block 30 is fixed by bolts B3. At the lower part of the intermediate block 30, the porous plate 31, the heat insulating plate 3
3. The heater block 34 is fixed by bolts B4. A first flow path 32 to which cool air is supplied is formed in the intermediate block 30, and the cool air in the first flow path 32 passes through the inside of the porous plate 31 and goes from the side surface of the porous plate 31 to the outside. Discharged. This is because the heater block 34 is the heater 3
5, the heat of the heater block 34 is prevented from being transmitted above the intermediate block 30, and the header 11, the first fixed block 18, the first movable block 20, the second fixed block 21, and the second Movable block 2
No. 3 etc. do not cause thermal distortion.

The crimping head 10 has the header 11 inserted into the head holder 8 and mounted on the head holder 8. When the header 11 thermally expands due to heat transfer from the heater block 34 and thermal distortion occurs. In addition, it becomes difficult to insert and remove the header 11 from the head holder 8, and the crimping head 10 cannot be removed and replaced. Further, the first fixed block 18, the first movable block 20, the second fixed block 21,
When the second movable block 23 generates thermal distortion, the arc surface is also deformed, so that a smooth tilting operation cannot be performed and uneven compression of the bumps occurs. Therefore, the above-mentioned problem caused by heat is solved by providing the heat insulating portions such as the porous plate 31 and the heat insulating plate 33. In the present embodiment, cold air is positively blown into the porous plate 31 to sufficiently enhance the heat insulating effect.

Then, below the heater block 34,
A suction tool 36 for sucking the electronic component P with bumps is fixed, and the electronic component P with bumps is sucked when the suction tool 36 and the second flow path 37 formed in the heater block 34 become negative pressure. Has become. In addition, Q is a bump of the electronic component P with a bump.

Next, each step of the method for crimping an electronic component with bumps according to the present embodiment will be described with reference to FIG. First, in step 1, the discharge of the compressed air is stopped, and the electronic component P with bumps is sucked by the suction tool 36 in a tilt lock state (step 2).

Next, the platen 4 is set immediately below the pressure bonding head 10, and compressed air is discharged.
The crimping head 10 is lowered toward the surface plate 4, and the bumps Q are pressed against the surface plate 4 to slightly crush the bumps Q (step 4). As a result, even if the height of the bumps Q varies, the plurality of bumps Q
Are aligned on one plane.

Next, a tilt lock is performed (Step 5), the posture of the bump Q having a uniform height is restrained as it is, and the pressure bonding head 10 is raised so that the substrate 1 is positioned directly below the pressure bonding head 10. Then, the table 3 is driven.
Then, as shown by the broken line in FIG. 1, the camera unit 17 is moved directly below the bump Q, and the bump Q and the circuit pattern of the substrate 1 are observed to recognize the positions of both.
Is driven to perform relative positioning between the two (step 6).

When the alignment is completed, the pressure bonding head 10 is lowered toward the substrate 1 while maintaining the tilt lock (step 7), and the load signal of the load cell 9 is monitored.
Here, when the bump Q lands on the substrate 1, the load indicated by the load signal sharply increases. Therefore, when this increase is detected, it is assumed that the bump Q lands (step 8).

When the landing is detected, the tilt lock is released (step 9), and the bump Q is pressed on the circuit pattern of the substrate 1 (step 10). Here, even if the upper surface of the substrate 1 and the plane on which the lower end surfaces of the plurality of bumps Q are aligned are not completely parallel, the bumps Q are aligned by performing the tilting in the directions of the arrows M1 and M2 described above. The plane can be made to follow the substrate 1 and both can be completely parallel.
In this case, since the electronic component with bump P is located at the center O1, O2 of the Y-arc surface 19 and the X-arc surface 22, the position of the electronic component with bump P does not change even when the tilt operation is performed. Therefore, the electronic component P with bumps can be pressed without displacement.

As described above, all the bumps Q are pressed against the electrodes 1a of the substrate 1 with an equal force, and a mounting failure can be prevented. The load at the time of press bonding is adjusted by controlling the Z motor 7 while detecting the load signal of the load cell 9 by the control unit C.

[0028]

The present invention is configured as described above.
All bumps on the chip are evenly distributed on the substrate electrodes
It can be thermocompression bonded and can be accurately mounted on a substrate.

[Brief description of the drawings]

FIG. 1 is a block diagram of a crimping apparatus for an electronic component with bumps according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of a crimping head of a crimping apparatus for an electronic component with bumps according to an embodiment of the present invention.

FIG. 3 is a cross-sectional view of a crimping head of a crimping apparatus for an electronic component with bumps according to an embodiment of the present invention.

FIG. 4 is a flowchart of a method for crimping an electronic component with bumps according to an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 1a Electrode 3 Table 10 Crimping head 11 Header 18 1st fixed block 19 Y arc surface 20 1st movable block 21 2nd fixed block 22 X arc surface 23 2nd movable block 27 Pulling-up rod (pressing means) 28 ball (Pressing means) 29 Spring (Pressing means) 36 Suction tool P Electronic component with bump

Continuation of front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H01L 21/60

Claims (1)

(57) [Claims] 1. A by landing a bump of the electronic component with bumps on electrodes of the substrate placed on the table, a thermal pressure <br/> deposition apparatus for electronic components bumped thermocompression bonding the bump to the electrode by crimping head A first fixed block having a lower surface formed of a Y-arc surface and a first movable block having an upper surface contacting the Y-arc surface and rotating along the Y-arc surface by the thermocompression bonding; A second fixed block provided below the first movable block, the lower surface of which is an X-arc surface, and the upper surface of which is in contact with the X-arc surface, and is formed by the thermocompression bonding.
What the second movable block is rotated along the X arcuate surface
And a heat insulating part below the second movable block in order from the top.
, Heat block with heater, and electronic part with bump
A thermocompression bonding device for electronic components with bumps, which is equipped with a suction tool for vacuum-sucking components.