JP3275756B2 - 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 for bonding a bump of an electronic component with bumps to an electrode of a work by thermocompression bonding.

[0002]

2. Description of the Related Art As a method for mounting an electronic component with a bump such as a flip chip on a work such as a substrate, a method using a thermocompression bonding head is known. The thermocompression head has a structure in which a crimping tool is held on the lower surface of a heat block, and heats the crimping tool to a high temperature (generally, about 200 ° C.) by transferring heat from the heat block. The bump of the attached electronic component is pressed against the electrode of the work and thermocompression-bonded. In this case, it is known that vibration is applied to the crimping tool to enhance the joining effect.

FIG. 9 is a partial front view of a thermocompression head of a conventional thermocompression bonding apparatus for electronic components with bumps. A heat block 4 is mounted on a lower portion of the main body 1 via heat insulating materials 2 and 3, and a crimping tool 5 is mounted on a lower surface of the heat block 4. Reference numeral 6 denotes a heater built in the heat block 4. The arm 7 extends from the main body 1 to the side,
A horn 8 is held at a lower end of the arm 7 in a horizontal posture. The tip of the horn 8 is in contact with the side surface of the heat block 4, and a piezoelectric element 9 as a vibrator is attached to the rear end. Reference numeral 10 denotes a flip chip, on the lower surface of which a bump 11 is projected. Reference numeral 12 denotes a substrate as a work, on which an electrode 13 of a circuit pattern is formed.

Next, the operation will be described. As shown, the bumps 11 of the flip chip 10 are landed on the electrodes 13 of the substrate 12, and the flip chip 10 is
Press on 2. The crimping tool 5 is heated by the heat transfer from the heat block 4. When the piezoelectric element 9 is driven, the horn 8 vibrates in its longitudinal direction A, whereby the crimping tool 5 vibrates in the direction of arrow B. Accordingly, the bumps 11 are heated by the heat transfer from the crimping tool 5 and subjected to vibration in the horizontal direction B, so that the bumps 11 are thermocompression bonded to the electrodes 13 of the substrate 12 and bonded. When the thermocompression bonding operation is completed, the thermocompression bonding head is raised.

[0005]

However, the conventional thermocompression bonding head has the following problems. First, since the horn 8 is arranged in a horizontal position and applies vibration to the heat block 4 from the side, the width W1 of the thermocompression bonding head increases, and the thermocompression bonding head increases in size.

Second, when the horn 8 vibrates in its longitudinal direction A, the heat block 4 and the crimping tool 5 reciprocate around the upper point O and vibrate. Therefore, the vibration direction (arrow B) of the crimping tool 5 is not strictly a horizontal direction but a rotation direction about the point O. In order to improve the bonding property of the bump 11 to the electrode 13, a crimping tool 5
Is desirably vibrated in the horizontal direction parallel to the upper surface of the substrate 12 as much as possible. Therefore, strictly speaking, it is difficult to obtain a sufficient bonding property with a conventional device that does not vibrate in the horizontal direction.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a thermocompression bonding apparatus for electronic components with bumps, which can make the thermocompression bonding head small and compact. It is another object of the present invention to provide a thermocompression bonding apparatus for electronic components with bumps, which can vibrate a crimping tool in a horizontal direction to improve the bonding between a bump and an electrode.

[0008]

SUMMARY OF THE INVENTION The present invention relates to a thermocompression bonding apparatus for electronic components with bumps for thermocompression bonding a bump of an electronic component with bumps to an electrode of a work positioned on a table. The head is disposed on the side of the heat block, a main body, a heat block provided below the main body, a crimping tool mounted on a lower portion of the heat block to thermocompress the electronic component with bumps to the work. A vibrator and a notch formed in the heat block to form a flexible hinge, thereby making the heat block a structure equivalent to a parallel link mechanism, and disposing the vibrator in an upright posture or an inclined posture, Vertical vibration of the vibrator is converted into horizontal vibration and transmitted to the side surface of the heat block, and the crimping tool is vibrated in the horizontal direction.

[0009]

According to the present invention having the above-mentioned structure, the transverse width of the thermocompression bonding head can be reduced by arranging the vibrator in the standing posture or the inclined posture, and the thermocompression bonding head can be reduced in size and size. In addition, by forming a notch in the heat block to form a flexible hinge, the heat block has a structure equivalent to a parallel link mechanism. Vibrating to improve the bonding property of the bump to the electrode.

An embodiment of the present invention will be described below with reference to the drawings. 1 is a front view of a thermocompression bonding apparatus for electronic components with bumps according to an embodiment of the present invention, FIG. 2 is a partial front view of the thermocompression bonding head, FIG. 3 is a perspective view of the same heat block, and FIG. FIG. 5 is a partial front view of the pressure bonding head, FIG. 5 is a model diagram of the heat block, and FIGS. 6 and 7 are equivalent circuit diagrams of the vibration mechanism.

First, the overall structure of a thermocompression bonding apparatus for electronic components with bumps will be described with reference to FIG. Reference numeral 20 denotes a support frame, on the front surface of which is a first lifting plate 21 and a second lifting plate 2
2 is provided to be able to move up and down freely. A cylinder 23 is mounted on the first lifting plate 21, and a rod 24 thereof is connected to the second lifting plate 22. A thermocompression bonding head 30 is mounted on the second lifting plate 22. On the upper surface of the support frame 20, a Z-axis motor 25 is provided. Z-axis motor 25
Rotates the vertical feed screw 26. The feed screw 26 is screwed into a nut 27 provided on the back surface of the first lifting plate 21. Therefore, the Z-axis motor 25 is driven to drive the feed screw 2
When 6 rotates, the nut 27 moves up and down along the feed screw 26, and the first lifting plate 21 and the second lifting plate 22 also move up and down.

The thermocompression bonding head 30 is mainly composed of a rod-shaped main body 31. Next, the lower structure of the thermocompression bonding head 30 will be described with reference to FIG. The block 3 is located below the main body 31.
2. A heat block 34 is mounted via a heat insulating material 33. The heat block 34 contains two heaters 35. A crimping tool 36 is mounted on the lower surface of the heat block 34. The crimping tool 36 presses the bump 11 of the flip chip 10 against the electrode 13 of the substrate 12.

2 and 3, the heat block 34 is formed with two inverted U-shaped cutouts 37 on the left and right sides, and the heater 35 is built in the cutout 37.
By forming the notch 37, the heat block 34
Both sides and the center of the center in the height direction are flexible hinges 38 (see also FIG. 3).

In FIG. 2, vertical blocks 40 are arranged on both sides of the heat block 34. The outer surface of the block 40 is partially cut away, and a piezoelectric element 41 as a vibrator is mounted on the cut portion. The piezoelectric element 41 is mounted in a standing posture, and its vibration direction is the vertical direction a. By arranging the piezoelectric element 41 in the upright posture as described above, the width W2 of the thermocompression bonding head 30 is reduced.
Is smaller.

A deep groove 42 is cut out at the center of the block 40 in the vertical direction, and the portion where the groove 42 is formed is a flexible (thin) hinge portion 43. A projection 44 is provided on the lower inner surface of the block 40, and the tip of the projection 44 abuts or is connected to the side surface of the heat block 34. Therefore, when the piezoelectric element 41 vibrates in the vertical direction a, the lower part of the block 40 vibrates in the direction of the arrow b so as to rotate about the flexible hinge 43. This vibration is transmitted to the heat block 34 via the projection 44, and the lower portion of the heat block 34 is
Vibrates in the horizontal direction c around 8.

FIG. 5 schematically shows the structure of the heat block 34. The heat block 34 is a flexible hinge 3
8 divides the upper part 34a and the lower part 34b into a structure equivalent to a parallel link mechanism. Therefore, when vibration in the direction of arrow b is applied via the projection 44, the lower portion 34b performs a parallel link motion and vibrates in the horizontal direction c.

In FIG. 1, a substrate 12 is a substrate holder 50.
The substrate holder 50 is placed on the table 51. The table 51 is a movable table, and horizontally moves the substrate 12 in the X direction and the Y direction.
Adjust the position of 2.

Reference numeral 52 denotes a camera, which is a single-axis table 53.
It is attached to. Reference numeral 54 denotes a lens barrel extending forward from the camera 52. The camera 52 is moved forward along the uniaxial table 53, and the tip of the lens barrel 54 is attracted to and held by the lower surface of the crimping tool 36 as shown by the broken line.
0 and the substrate 12, and the positions of the flip chip 10 and the substrate 12 are observed by the camera 52 in this state. Then, a relative displacement between the flip chip 10 and the substrate 12 is detected based on the observation result. The detected displacement is
The correction is performed by driving the table 51 to move the substrate 12 horizontally in the X direction or the Y direction, whereby the bumps 11 of the flip chip 10 and the electrodes 13 of the substrate 12 are aligned.

In FIG. 1, reference numeral 60 denotes a main control unit, which controls the Z-axis motor 25 via a motor drive unit 61, controls the table 51 via a table control unit 62, and receives a signal via a recognition unit 63. Connected to the camera 52. The cylinder 23 is connected to the main control unit 60 via the load control unit 64.
The flip chip 10 is connected to the substrate 1 by the protrusion of the rod 24 of the cylinder 23, that is, the crimping tool 36.
2 is controlled.

The thermocompression bonding apparatus for electronic components with bumps is constructed as described above. Next, the overall operation will be described.
In FIG. 1, the flip chip 10 is held on the lower surface of the crimping tool 36, and the flip chip 10 is positioned above the substrate 12. Then, the lens barrel 54 is advanced to obtain the images of the flip chip 10 and the substrate 12 with the camera 52, and the image data is sent to the recognition unit 63. The main controller 60 detects the relative displacement between the flip chip 10 and the substrate 12 from the image data, and according to the detection result, the table 5
1 is driven to horizontally move the substrate 12 to correct the positional deviation.

Next, the Z-axis motor 25 is driven to lower the thermocompression bonding head 30 so that the bump 11 of the flip chip 10 lands on the electrode 13 of the substrate 12 and the cylinder 23 is driven to move the flip chip 10 to the substrate. Press on 12. At this time, the flip chip 10 is heated by the heat transfer from the heat block 34. In addition, flip chip 10
Is pressed against the substrate 12, the piezoelectric element 41 is driven. Then, as described with reference to FIGS. 2 and 5, the heat block 34 vibrates in the horizontal direction c, and the bump 11 is firmly joined to the electrode 13. Next, the Z-axis motor 25 is driven in the reverse direction to raise the thermocompression bonding head 30,
The pressing state of the flip chip 10 is released, and the driving of the piezoelectric element 41 is stopped. Thus, a series of operations is completed.

In FIG. 4, when the piezoelectric element 41 vibrates in the vertical direction a, the lower portion of the block 40 vibrates in the direction of arrow b around the thin hinge portion 43, and this vibration
4 to the heat block 34. here,
If the ratio of the distance L1 between the flexible hinge 43 and the piezoelectric element 41 and the distance L2 between the flexible hinge 43 and the projection 44 is increased, the amplitude of the piezoelectric element 41 is amplified by this ratio and the heat block 34 By transmitting the vibration, the heat block 34 is largely vibrated, so that the bonding effect between the bump 11 and the electrode 13 can be enhanced.

Incidentally, the left and right piezoelectric elements 41 shown in FIG.
However, when they vibrate in a direction to cancel each other's vibrations, the heat block 34 does not vibrate. Therefore, the left and right piezoelectric elements 4
1 need to vibrate in opposite directions so as not to cancel each other's vibrations.

FIGS. 6 and 7 show equivalent circuits of the right and left vibrators 41, and show a method for vibrating the left and right vibrators 41 in directions opposite to each other. 6, reference numeral 65 denotes an AC power supply for driving the piezoelectric element 41, C1,
C2 is a capacitor equivalent to the right and left vibrators 41,
They are connected in series. Capacitor C1 and capacitor C
2 alternately oscillates positively and negatively. In the case of FIG. 7, the capacitors C1 and C2 are connected in parallel, and oscillate positively and negatively alternately. Therefore, if the left and right piezoelectric elements 41 are wired as shown in FIGS. 6 and 7, the left and right piezoelectric elements 41 vibrate so as not to cancel each other's vibrations.

FIG. 8 is a partial front view of a thermocompression bonding head for an electronic component with bumps according to another embodiment of the present invention. In this embodiment, the blocks 40 holding the piezoelectric elements 41 are arranged on both sides of the heat block 34 in an inclined posture. Therefore, the width W3 of the thermocompression bonding head 30 can be made smaller than that of the conventional example shown in FIG. Of course, in each embodiment, only one block 40 holding the piezoelectric element 41 may be disposed on only one side of the heat block 34. In this case, the widths W2 and W3 of the thermocompression bonding head 30 are reduced. can do.

Also in this embodiment, when the piezoelectric element 41 vibrates in the longitudinal direction a, the lower portion of the block 40 vibrates in the direction of arrow b around the thin hinge portion 43, and the heat block 34 vibrates in the horizontal direction c. . Therefore, this embodiment also has the same operation and effect as the above embodiment.

[0027]

According to the present invention, by arranging the vibrator in the upright posture or the inclined posture, the lateral width of the thermocompression bonding head can be reduced, and the thermocompression bonding head can be downsized. Also, by forming a notch in the center of the heat block in the height direction to form a flexible hinge, the heat block has a structure equivalent to a parallel link mechanism. By vibrating the crimping tool on the lower surface in the horizontal direction, the bonding property of the bump to the electrode can be improved.

[Brief description of the drawings]

FIG. 1 is a front view of a thermocompression bonding apparatus for electronic components with bumps according to an embodiment of the present invention.

FIG. 2 is a partial front view of a thermocompression bonding head for an electronic component with bumps according to an embodiment of the present invention.

FIG. 3 is a perspective view of a heat block of the electronic component with bumps according to the embodiment of the present invention;

FIG. 4 is a partial front view of a thermocompression bonding head for an electronic component with bumps according to an embodiment of the present invention.

FIG. 5 is a model diagram of a heat block of the electronic component with bumps according to one embodiment of the present invention.

FIG. 6 is an equivalent circuit diagram of a vibration mechanism of the electronic component with bumps according to one embodiment of the present invention.

FIG. 7 is an equivalent circuit diagram of a vibration mechanism of the electronic component with bumps according to one embodiment of the present invention.

FIG. 8 is a partial front view of a thermocompression bonding head for an electronic component with bumps according to another embodiment of the present invention.

FIG. 9 is a partial front view of a thermocompression bonding head of a conventional thermocompression bonding apparatus for electronic components with bumps.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Flip chip 11 Bump 12 Substrate 13 Electrode 30 Thermocompression head 31 Main body 34 Heat block 36 Crimping tool 37 Notch 38 Flexible hinge part 40 Block 41 Piezoelectric element (vibrator) 43 Flexible (thin wall) hinge part 50 Table

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H01L 21/60 311 H01L 21/607

Claims (1)

(57) [Claims] 1. A thermocompression bonding apparatus for electronic components with bumps for bonding a bump of an electronic component with bumps to an electrode of a work positioned on a table by thermocompression bonding. A heat block provided below the section, a crimping tool attached to the lower portion of the heat block to thermocompress the electronic components with bumps to the work, and a vibrator arranged on the side of the heat block. The notch is formed to form a flexible hinge, so that the heat block has a structure equivalent to a parallel link mechanism, and the vibrator is arranged in an upright posture or an inclined posture. A thermocompression bonding apparatus for electronic components with bumps, which converts the vibration into a horizontal vibration and transmits the vibration to a side surface of the heat block, and vibrates the pressure bonding tool in a horizontal direction.