JPH1145912A - Apparatus and method of bonding electronic components having bumps - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an apparatus and a method of bonding electronic components having bumps which tightly bond to a work the electronic components vacuum-chucked at the lower face of a vacuum chuck tool while the components are well vibrated. SOLUTION: A flip chip 30 vacuum-chucked by the lower face of a vacuum chuck tool 22 is elastically clamped with a rib 22a and leaf spring 24 and ultrasonically vibrated by a piezoelectric element, bumps 31 are pressed and bonded to electrodes on a board. As the chip 30 is elastically clamped, the vibration of the tool 22 is well transmitted to the chip 30 to thereby bond the bumps tightly.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bonding apparatus and a bonding method for electronic components with bumps for bonding bumps of electronic components with bumps to a work such as a substrate.

[0002]

2. Description of the Related Art As a method of mounting an electronic component with a bump such as a flip chip on a work such as a substrate, a method using a suction tool is known. In this method, a bump of an electronic component with a bump that is vacuum-sucked on the lower surface of a suction tool is pressed against an electrode of a work and bonded.
In this case, it is known to apply ultrasonic vibration to the suction tool in order to enhance the bonding effect.

[0003]

However, since the electronic components with bumps are only held by vacuum suction on the lower surface of the suction tool, the electronic components with bumps are not affected even if ultrasonic vibration is applied to the suction tool. Slip occurs in the vibration direction with respect to the suction tool, and the vibration force is easily reduced, and therefore, there is a problem that it is difficult to sufficiently vibrate the electronic component with bumps and firmly bond it to the work.

Accordingly, the present invention provides a bonding apparatus and a bonding method for an electronic component with bumps, which can firmly bond to a work while sufficiently vibrating the electronic component with bumps held by vacuum suction on the lower surface of a suction tool. The purpose is to do.

[0005]

SUMMARY OF THE INVENTION A bonding apparatus for an electronic component with a bump according to the present invention includes a suction tool for vacuum-holding and holding an electronic component with a bump with the bump forming surface of the electronic component with a bump facing down, and the suction tool. Clamp means for contacting the side surface of the electronic component with bumps held by the tool to clamp the electronic component with bumps, ultrasonic vibration applying means for applying ultrasonic vibration to the suction tool, and the suction tool and clamp means; Lifting and lowering means for integrally raising and lowering the ultrasonic vibration applying means with respect to the work for bonding the electronic component with bumps.

Further, in the method of bonding an electronic component with a bump according to the present invention, the electronic component with a bump held by being vacuum-sucked on the lower surface of a suction tool is clamped by a clamp means.
In this state, the bumps of the electronic component with bumps are pressed against the electrodes of the workpiece, and the bumps are bonded to the electrodes while applying ultrasonic vibration to the bonding surface between the bumps and the electrodes by the ultrasonic vibration applying means.

[0007]

According to the present invention, the ultrasonic vibration of the suction tool is sufficiently transmitted to the electronic component with the bump, and the electronic component with the bump is strongly ultrasonically vibrated and bonded to the work. it can.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a front view of a bonding apparatus for an electronic component with bumps according to an embodiment of the present invention, FIG. 2 is an exploded perspective view of the crimping unit, FIG. 3 is a perspective view of an assembled state of the crimping unit, and FIG. FIG. 5 is a partial perspective view of the crimping unit, FIG. 5 is a bottom view of a horn of the crimping unit, FIG. 6 is a cross-sectional view of the crimping unit, and FIG. 7 is a front view of the crimping unit.

First, the overall structure of a crimping apparatus for an electronic component with bumps will be described with reference to FIG. Reference numeral 1 denotes a support frame, on the front surface of which a first lifting plate 2 and a second lifting plate 3 are provided so as to be able to move up and down. A cylinder 4 is mounted on the first lifting plate 2, and its rod 5 is connected to the second lifting plate 3. The bonding head 10 is mounted on the second lifting plate 3. On the upper surface of the support frame 1, a Z-axis motor 6 is provided. The Z-axis motor 6 has a vertical feed screw 7
To rotate. The feed screw 7 is screwed into a nut 8 provided on the back surface of the first lifting plate 2. Therefore, when the Z-axis motor 6 is driven and the feed screw 7 is rotated, the nut 8 moves up and down along the feed screw 7, and the first lifting plate 2 and the second lifting plate 3
Also move up and down.

In FIG. 1, a substrate 32 is a substrate holder 34.
The substrate holder 34 is placed on a table 35. The table 35 is a movable table, and moves the substrate 32 horizontally in the X direction and the Y direction.
2 is positioned at a predetermined position.

Reference numeral 42 denotes a camera, a one-axis table 43
It is attached to. Reference numeral 44 denotes a lens barrel extending forward from the camera 42. The camera 42 is moved forward along the uniaxial table 43, and the tip of the lens barrel 44 is positioned between the flip chip 30 and the substrate 32, which are held by suction on the lower surface of the suction tool 22 (described later), as indicated by a chain line. In this state, the positions of the flip chip 30 and the substrate 32 are observed by the camera 42. Then, a relative displacement between the flip chip 30 and the substrate 32 is detected based on the observation result. The detected displacement is determined by driving the table 35 to move the substrate 32 in the X direction or Y direction.
Is corrected by horizontally moving the bumps 31 of the flip chip 30 and the electrodes 33 of the substrate 32.
(FIG. 7) is performed.

In FIG. 1, reference numeral 50 denotes a main control unit, which controls the Z-axis motor 6 via a motor drive unit 51, controls the table 35 via a table control unit 52, and receives a signal via a recognition unit 53. Connected to the camera 42. Further, the cylinder 4 is connected to the main control unit 50 via a load control unit 54, and the protrusion output of the rod 5 of the cylinder 4, that is, the force of pressing the flip chip 30 against the substrate 32 by the crimping tool 22 is controlled.

In FIG. 1, a bonding head 10 mainly includes a main body 11, and a crimping unit 12 is provided below the main body 11. Next, the structure of the crimping unit 12 will be described with reference to FIGS. 2 to 4
Shows the crimping unit 12 upside down.

2 and 3, the crimping unit 1
2 comprises an upper unit 13 and a lower unit 20. The upper unit 13 is configured by mounting a U-shaped block 15 on the lower surface of a plate body 14. A screw hole 16 is formed in the block 15, and a pin 17 as a positioning member is protrudingly provided. A rib 18 as a positioning portion is protruded from the main surface side of the block 15.

Next, the structure of the lower unit 20 will be described.
2 and 3, the lower unit 20 includes a horn 21
Is the subject. The horn 21 is a long rod-like body, and its both ends 21a are thick, and the central part 21b is tapered so as to gradually taper toward the central point. A piezoelectric element 19, which is an ultrasonic vibration applying means, is attached to both ends 21a of the wall. The piezoelectric element 19 is driven by the ultrasonic transducer driving unit 55 (FIG. 1).

Referring to FIG. 4, a suction tool 22 is provided on a central lower surface of the horn 21. In the center of the suction tool 22, a flip chip 30, which is an electronic component with a bump, is provided.
Suction holes 23 are formed for vacuum suction and hold.
A rib 22a protrudes from the side. A leaf spring 24 is mounted on the side surface of the central part of the horn 21, and a plate-like pressing element 25 for pressing the leaf spring 24 is provided on the other surface side. The planar shape of the pressing element 25 is a U-shape surrounding the suction tool 22. The pressing element 25 is connected to a rod 26a of a cylinder 26 (see also FIGS. 3 and 6).

2 and 3, the horn 21 has four mounting portions 27 protruding therefrom. Four mounting parts 27
Are located on four sides of the suction tool 22, and the suction tool 22 is located at the center of the four mounting portions 27. A screw hole 28 is formed in the mounting portion 27. The lower unit 20 is detachably mounted on the lower surface of the upper unit 13 by aligning the screw hole 28 with the screw hole 16 of the block 15 and screwing the screw 29. In this case, the two surfaces of the mounting portion 27 abut on the pins 17 and the ribs 18 as positioning portions, and the horizontal positioning of the lower unit 20 with respect to the upper unit 13 is performed.

In FIG. 6, the flip chip 30 is held by vacuum suction on the lower surface of the suction tool 22. When the suction tool 22 holds and releases the flip chip 30, the following operation is performed. . When the rod 26a of the cylinder 26 is protruded, the pressing element 25 advances toward the leaf spring 24, and when the rod 26a is retracted, the pressing element 2
5 retreats. Accordingly, when the suction tool 22 picks up the flip chip 30 provided on a tray or the like by vacuum suction, the presser 25 is advanced to forcibly bend the leaf spring 24 to the dashed line position. As a result, the interval between the rib 22a and the leaf spring 24 is widened, and in this state, the suction tool 22 vacuum-adsorbs and picks up the flip chip 30.

In FIG. 6, when the suction tool 22 picks up the flip chip 30, the rod 26a of the cylinder 26 is retracted. Then, the presser 25 retreats and separates from the leaf spring 24, and the leaf spring 24 is deformed to the position shown by the solid line due to its own elasticity, whereby the flip chip 30 is elastically clamped by the rib 22a and the leaf spring 24. That is, the rib 22a and the leaf spring 24 are clamping means for elastically clamping the flip chip 30, and the pressing element 25 and the cylinder 26 are operating means of the clamping means. The piezoelectric element 19 gives the drive of the horn 21 in the longitudinal direction N (FIG. 4), but the clamping direction by the clamp means is a direction orthogonal to the vibration direction, and the clamp means elastically clamps the flip chip 30. . Therefore, when the horn 21 vibrates in the longitudinal direction, the flip chip 30 can vibrate in the same direction N together with the rib 22a and the leaf spring 24.

In FIG. 5, A1 to A4 are nodes of vibration of the horn 21. Among them, A1 and A4 are fixing points of the piezoelectric element 19, and A2 and A3 are mounting portions 27 with screws 29.
Is a fixed point. When the piezoelectric element 19 is driven, the horn 2
1 vibrates with nodes A1 to A4 as nodes. The suction tool 22 is located at the center antinode B, so that when the horn 21 vibrates, the suction tool 22 vibrates strongly. Thus, the suction tool 22 is provided at the center point of the long horn 21, and the central portion 21b of the horn 21 has a tapered shape that gradually becomes thinner toward the suction tool 22,
Further, by providing the attachment portions 27 on four sides of the suction tool 22, the suction tool 22 can be vibrated stably and strongly.

The bonding apparatus for an electronic component with bumps is constructed as described above. Next, the overall operation will be described. In FIG. 1, the flip chip 30 is held on the lower surface of the suction tool 22, and the flip chip 30 is positioned above the substrate 32. Then, the lens barrel 44 is advanced, and the images of the flip chip 30 and the substrate 32 are obtained by the camera 42.
The image data is sent to the recognition unit 53. The main controller 50 detects a relative displacement between the flip chip 30 and the substrate 32 from the image data, drives the table 35 according to the detection result, and moves the substrate 32 horizontally to correct the displacement.

Next, the Z-axis motor 6 is driven to lower the bonding head 10 and the bumps 31 of the flip chip 30.
Is landed on the electrode 33 of the substrate 32, and the cylinder 4 is driven to press the flip chip 30 against the substrate 32 (FIG. 7). At this time, the substrate 32 is heated by a heating means (not shown).
Is heated by the heat transfer from When the flip chip 30 is pressed against the substrate 32, the piezoelectric element 19 is driven. Then, in FIG. 7, the flip chip 30 vibrates in the horizontal direction N, and the bump 31 is bonded to the electrode 33 of the substrate 32. The bonding process will be described in detail below. That is, bump 3
In the initial stage in which 1 is bonded to the electrode 33, the bump 31 and the electrode 33 are simply in contact with each other, so that the frictional resistance between them is smaller than the holding force (clamping force) by the clamping means, and therefore, the flip chip 30 Vibrates together with the suction tool 22 to destroy the oxide film on the surfaces of the bumps 31 and the electrodes 33. This oxide film is formed between the bump 31 and the electrode 33.
Therefore, it is desirable to destroy the conductive material because the conductive property of the conductive material is impaired.

Next, as the bonding between the bump 31 and the electrode 33 proceeds, the flip chip 30 becomes less likely to reciprocate with respect to the electrode 33. Here, when the flip chip 30 is reciprocally oscillated by force, the bump 3 where the angle bonding has advanced is performed.
1 comes off the electrode 33. However, in this means, when the bonding proceeds and the bonding force between the bump 31 and the electrode 33 increases, the flip chip 30
4 and the ribs 22a are elastically clamped, so that the contact surface between the flip chip 30 and the leaf spring 24 and the rib 22a slips, and the flip chip 30 reciprocates freely in the horizontal direction N, and finally the bump 31 Will be firmly bonded to the electrode 33.

When the bonding of the flip chip 30 is completed as described above, the Z-axis motor 6 is driven in the reverse direction to raise the bonding head 10 so that the pressed state of the flip chip 30 is released and the piezoelectric element 19 is released. Stop driving. Thus, a series of operations is completed.

[0025]

According to the present invention, the ultrasonic vibration of the suction tool can be sufficiently transmitted to the electronic component with bump, and the electronic component with bump can be strongly ultrasonically vibrated and bonded to the work.

[Brief description of the drawings]

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

FIG. 2 is an exploded perspective view of a crimping unit of the bonding device for electronic components with bumps according to one embodiment of the present invention.

FIG. 3 is a perspective view showing an assembled state of a pressure bonding unit of the bonding device for electronic components with bumps according to one embodiment of the present invention;

FIG. 4 is a partial perspective view of a crimping unit of the bonding device for electronic components with bumps according to one embodiment of the present invention;

FIG. 5 is a bottom view of a horn of a crimping unit of the bonding device for electronic components with bumps according to an embodiment of the present invention.

FIG. 6 is a cross-sectional view of a crimping unit of the bonding device for electronic components with bumps according to one embodiment of the present invention.

FIG. 7 is a front view of a crimping unit of the bonding device for electronic components with bumps according to one embodiment of the present invention;

[Explanation of symbols]

 Reference Signs List 4 cylinder 6 motor 7 feed screw 8 nut 10 bonding head 12 pressure bonding unit 13 upper unit 19 piezoelectric element 20 lower unit 21 horn 22 suction tool 22a rib 24 leaf spring 25 presser 26 cylinder 27 mounting portion 30 flip chip 31 bump 32 substrate 33 electrode

Claims (2)

[Claims] A suction tool for vacuum-holding the electronic component with the bump with the bump forming surface of the electronic component with the bump facing downward, and a bump contacting a side surface of the electronic component with the bump held by the suction tool. Clamping means for clamping the attached electronic component, ultrasonic vibration applying means for applying ultrasonic vibration to the suction tool, and applying the suction tool, the clamping means, and the ultrasonic vibration applying means to a work for bonding the electronic component with bumps. And an elevating means for integrally elevating and lowering the electronic component with bumps. 2. An electronic component with a bump held by vacuum suction on a lower surface of a suction tool by a clamp means.
In this state, the bump of the electronic component with a bump is pressed against the electrode of the work, and the bump is bonded to the electrode while applying ultrasonic vibration to the joint surface between the bump and the electrode by the ultrasonic vibration applying means. Bonding method for electronic components.