JP2000208541A - Bump bonding device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To firmly bond a bump on an electrode pad and to form a bump large in height. SOLUTION: A piston slide hole 22 which extends in the horizontal and vertical directions is provided on a head member 21 of a bump bonding device. A piston 26 which can slide in the vertical direction is housed in the piston slide hole. An opening 24 linking the piston sliding hole 22 via a guide hole 23 is provided on the tip of the head member 21. The head member 21 is provided with a wire inserting hole 25 which is opened on the bottom of the piston slide hole 22. A suction device 28, which sucks a wire 6 within a wire inserting hole 25 is provided in the vicinity of the tip of a head member 21. A dischargeable electrode is mounted on the wire 6 on the top end of the suction device 28.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bump bonding apparatus for forming a bump on an electrode pad of an electronic component such as a semiconductor element, a substrate, a connector, etc., for example, composed of an integrated circuit.

[0002]

2. Description of the Related Art In recent years, in order to mount a semiconductor element, such as an integrated circuit, as an electronic component on a substrate with a minimum area, a bump serving as a protruding electrode is formed on an electrode of the semiconductor element. The electrode of the semiconductor element is connected to an external electrode such as a substrate.

A conventional bump bonding apparatus for forming such a bump will be described with reference to FIGS.

In FIG. 1, reference numeral 1 denotes a base of a wire bonding apparatus. The base 1 has a column 2 extending upward and downward,
It is roughly constituted by a table support arm 3 provided below the column 2.

Reference numeral 4 denotes an XY attached to the table support arm 3.
On the XY table 4, a semiconductor element 14 such as an integrated circuit described later is mounted. The XY table 4 moves the semiconductor element 14 in the X-axis and Y-axis directions that are horizontal planes.

[0006] 5 is a reel provided on the upper side of the column 2,
The reel 5 includes a tension generator 8 and a clamp 1 described later.
0 constitutes a wire supply means. The reel 5 is wound with a wire 6 made of a conductive metal material such as gold, aluminum, zinc, or copper for forming a bump 15 described later. Here, the wire 6 is formed in a thin thread shape having a diameter of, for example, about 20 to 50 μm.

[0007] Reference numeral 7 denotes a wire-supplying support arm provided on the upper side of the support column 2. At the tip of the wire-supplying support arm 7, a tension generator 8 for applying a constant tension to the wire 6 is provided. . A clamp support arm 9 that can be displaced upward and downward by a driving mechanism (not shown) is provided below the wire supply support arm 7, and the tip of the clamp support arm 9 supplies the wire 6. Is provided. The wire 6 supplied from the reel 5 reaches a head member 12 to be described later through the tension generator 8 and the clamp 10.

Reference numeral 11 denotes a head support arm, and the head support arm 1
A head member 12 is provided at the front end of the head 1. The head support arm 11 has a head support arm 11
There is provided another drive mechanism (not shown) for displacing the head upward and downward. For this reason, the head member 12 can be displaced upward and downward together with the clamp 10.

Here, the head member 12 is formed in a cylindrical shape as shown in FIG. 13, and a wire insertion hole 12A for inserting the wire 6 is formed in the center side thereof. The head member 12 is formed in a tapered shape that gradually becomes thinner toward the distal end, and a tapered opening 12B that is gradually expanded is formed in the lower open end of the wire insertion hole 12A. I have. The height H1 of the opening 12B
Is, for example, 40 μm as shown in FIG.
Is set to, for example, about 70 μm.

Reference numeral 13 denotes a torch rod provided near the distal end of the head member 12. The torch rod 13 generates a discharge toward the distal end of the wire 6 when the head member 12 is raised. Thereby, the torch rod 13 forms a substantially spherical ball portion 6A on the distal end side of the wire 6. Also, when the head member 12 descends toward the semiconductor element 14 side, the torch rod 13
In order not to hinder the movement of No. 2, it moves to the left as exemplified by the virtual line in FIG.

The prior art bump bonding apparatus has the above-described configuration, and its operation will be described below.

First, the semiconductor device 1 is placed on the XY table 4.
4 is placed. Then, a discharge is generated by the torch rod 13 on the distal end side of the wire 6 inserted into the head member 12 to form the ball portion 6A.

Next, with the clamp 10 closed, the clamp 10 and the head member 12 are lowered toward the electrode pad 14A of the semiconductor element 14. At this time, the semiconductor element 14 is previously heated to, for example, about 400 ° C. by a heater (not shown) provided below the XY table 4. For this reason, the ball portion 6A on the tip side of the wire 6 contacts the electrode pad 14A of the semiconductor element 14, and the ball portion 6A is pressed by the electrode pad 14A by the tip side of the head member 12. Thereby, the ball portion 6A
Is bonded to the electrode pad 14A by the action of temperature, pressure and the like.

Next, the clamp 10 and the head member 12
From the electrode pad 14A of the semiconductor element 14.
As a result, the ball portion 6 bonded to the electrode pad 14A
A is cut off from the wire 6 to form a bump 15 having a protruding shape.

By repeating such operations, the semiconductor device 1
The bumps 15 are formed on all the electrode pads 14A. Thereafter, as shown in FIG. 12, the semiconductor element 14 is joined to the external electrode 16A of the substrate 16. Finally, a thermosetting resin material 17 is sealed in a gap between the semiconductor element 14 and the substrate 16, and the resin material 17 is thermoset to fix the semiconductor element 14 to the substrate 15.

[0016]

In the above-described bump bonding apparatus according to the prior art, the semiconductor element 14 is bonded to the substrate 16 by sealing and curing a resin material 17 between the semiconductor element 14 and the substrate 16. .
For this reason, it is preferable that the height of the bump 15 that forms a gap between the semiconductor element 14 and the substrate 16 is high. Here, the height dimension of the bump 15 is
Is determined by the height H1 of the opening 12B provided on the tip side of the opening. For this reason, the height H of the opening 12B
When 1 is increased, the height of the bump 15 can be increased.

However, in this case, since the angle at which the opening 12B expands becomes small, the force pressing the ball portion 6A against the electrode pad 14A of the semiconductor element 14 becomes weak. Therefore, there is a problem that the bonding of the bump 15 is weakened and the bump 15 is easily peeled off from the electrode pad 14A.

The height of the bump 15 can also be increased by increasing the diameter D1 of the opening 12B together with the height H1 of the opening 12B. However, in this case, since the diameter of the bump 15 increases, it is necessary to increase the electrode pad of the semiconductor element, and on the contrary, the area of the entire semiconductor element increases.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a bump bonding apparatus capable of forming a bump having a high height while strongly bonding the bump to an electrode pad. .

[0020]

In order to solve the above-mentioned problems, the present invention provides a wire supplying means for supplying a wire for forming a bump on an electronic component, and a wire supplying means for supplying a wire supplied from the wire supplying means. The present invention is applied to a bump bonding apparatus including a head member that forms a bump by pressing a front end side against an electrode pad.

A feature of the first aspect of the present invention is that the head member is provided with a piston for pressing the distal end side of the wire toward the electrode pad. Thus, the distal end side of the wire can be pressed against the electrode pad by the piston. For this reason, a sufficient pressing force required for joining can be applied to the distal end side of the wire.

Further, the invention according to claim 2 is characterized in that the head member has an opening which expands and opens in a tapered shape on an end face on the tip end side of the head member and presses the tip end of the wire against the electrode pad. And a wire insertion hole through which the wire is inserted to guide the wire from the wire supply means into the opening, and the piston is moved from the wire insertion hole toward the opening by the wire. The distal end is cut from the remaining wire portion, and the distal end of the wire is pressed against the electrode pad in cooperation with the opening.

With this configuration, the distal end side of the wire can be cut from the remaining wire portion by the piston. Then, the distal end side of the wire cut by the piston and the opening can be pressed against the electrode pad.

Further, the invention according to claim 3 is provided with a suction device which is advanced and retracted with respect to the tip end side of the head member, and the suction device is configured to suck the wire from the opening. Thus, even when the distal end side of the wire is located in the opening, the distal end side of the wire can be guided to the distal end side of the head member and protruded by the suction device.

According to a fourth aspect of the present invention, the suction device is provided with an electrode for generating a discharge at the tip end of the wire. Thereby, the suction is performed by the suction device, and a discharge is generated by the electrode toward the tip of the wire protruding toward the suction device, so that a substantially spherical ball portion can be formed.

Further, the invention according to claim 5 is characterized in that the head member is provided with vibration generating means for generating ultrasonic vibration. With this configuration, the head member can be ultrasonically vibrated by the vibration generator to increase the bonding strength between the tip of the wire and the electrode pad.

[0027]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a bump bonding apparatus according to an embodiment of the present invention will be described in detail with reference to FIGS.

FIGS. 1 to 9 show a bump bonding apparatus according to a first embodiment of the present invention. In the present embodiment, the same components as those of the above-described prior art are denoted by the same reference numerals, and a description thereof will be given. It shall be omitted.

In FIG. 2, reference numeral 21 denotes a head member attached to the tip of the head support arm 11. The head member 21 is positioned at the center in the radial direction as shown in FIG. ) Is provided. The bottom side of the piston sliding hole 22 communicates with the opening 24 through a guide hole 23 described later. The head member 21 is provided with a piston slide hole 22, a guide hole 23, and an opening 24 coaxially. For this reason, a stepped through hole is formed in the head member 21 by the piston sliding hole 22, the guide hole 23, and the opening 24.

Reference numeral 23 denotes an opening 2 from inside the piston sliding hole 22.
The guide hole 23 is a guide hole for guiding the wire 6 toward the guide hole 4, and the diameter of the guide hole 23 is smaller than that of the piston slide hole 22. The upper end side of the guide hole 23 is open to the bottom side of the piston slide hole 22 and is a tapered portion 23A that gradually expands toward the piston slide hole 22. For this reason, the wire 6 in the piston slide hole 22 is smoothly guided to the opening 24 by the tapered portion 23A.

Reference numeral 24 denotes an opening provided on the front end surface of the head member 21. The opening 24 is provided with a guide hole 23.
And a tapered shape gradually expanding toward the tip end side of the head member 21. The height H2 of the opening 24 is, for example, 100 μm as shown in FIG.
The diameter D2 of the openings 24 is set to, for example, about 70 μm.

A wire insertion hole 25 is located near the piston slide hole 22 for inserting the wire 6. One end of the wire insertion hole 25 has a base end of the head member 21 as shown in FIG. Side and the other end side is located near the guide hole 23 and opens to the bottom side of the piston sliding hole 22.

For this reason, the wire 6 supplied from the reel 5 to the head member 21 through the tension generator 8 and the clamp 10 is guided into the piston sliding hole 22 through the wire insertion hole 25, and the head member 21 through the opening 24. Projecting from the tip side of the.

The open end of the wire insertion hole 25 at the other end is opened and closed by a piston 26 described later. Therefore, when the piston 26 moves up, the wire 6 is guided to the tip end side of the head member 21 through the wire insertion hole 25 and the guide hole 23. On the other hand, when the piston 26 descends, the other end of the wire insertion hole 25 is closed by the piston 26, so that the wire 6
Is cut by the piston 26.

Reference numeral 26 denotes a piston slidably inserted into the piston sliding hole 22. The piston 26 is slidably displaced in the axial direction by a driving device (not shown). This allows
As shown in FIG. 8, the piston 26 cuts the ball portion 6A on the distal end side of the wire 6 from the remaining wire portion 6B, and cooperates with the opening 24 of the head member 21 to form the ball portion 6A.
A is pressed against the electrode pad 14A of the semiconductor element 14.

A swing arm 27 is provided near the tip of the head member 21 so as to advance and retreat.
A suction device 28, an electrode 29, and a detector 30, which will be described later, are provided on the distal end side of 7. Also, the swing arm 27
When the head member 21 descends toward the semiconductor element 14, the movement of the head member 21 is not hindered.
It moves to the left as indicated by a virtual line in FIG.

Numeral 28 denotes a suction device for sucking the wire 6 located in the wire insertion hole 25 and projecting it from the tip of the head member 21. The suction device 28 is located at the tip of the swing arm 27 as shown in FIG. A substantially cylindrical tip portion 28A is provided, a recessed portion 28B is formed by expanding upward at the tip portion 28A, and a plurality of airs are formed on the bottom surface side of the recessed portion 28B and open to the recessed portion 28B. , An intake passage 28D for suction through the intake holes 28C, 28C,.

Reference numeral 29 denotes an electrode provided on the upper end side of the suction device 28, and a high-voltage power supply (not shown) is connected to the electrode 29. The electrode 29 forms a ball portion 6 </ b> A at the tip of the wire 6 by causing discharge on the tip side of the wire 6 protruding from the tip of the head member 21.

Numeral 30 denotes a capacitance type or optical type detector provided near the concave portion 28B of the suction device 28. The detector 30 has the tip of the wire 6 sucked into, for example, the concave portion 28B. That is to detect that.

The bump bonding apparatus according to the present embodiment has the above-described configuration. Next, the operation of the apparatus will be described with reference to FIGS.

First, a semiconductor element 14 is mounted on the XY table 4 as shown in FIG. And the head member 2
The first piston 26 is raised and the swing arm 27 is moved to position the suction device 28 near the tip of the head member 21.

Next, the clamp 10 is opened and the suction device 28 is operated as shown in FIG.
Air near the recessed portion 28B is sucked through D. At this time, since the wire 6 has been cut at the bottom side of the piston slide hole 22 by the piston 26 at the time of the previous operation, for example, the distal end side of the wire 6 is
Is located in the middle part of. Therefore, the wire 6 located in the middle of the piston slide hole 22 is sucked by the suction device 28, and the tip of the wire 6 enters the recess 28B. When the detector 30 detects that the tip of the wire 6 has entered the recessed portion 28B, the operation of the suction device 28 is stopped.

Next, as shown in FIG. 6, by applying a high voltage to the electrode 29, a discharge is generated at the distal end of the wire 6 to form a ball portion 6A at the distal end of the wire 6.
Then, after the swing arm 27 is moved, the head member 21 is moved together with the clamp 10 together with the clamp 10 while the clamp 10 is closed, as shown in FIG.
Lower toward. As a result, the ball portion 6A comes into contact with the electrode pad 14A.

Next, the upward and downward movements of the clamp 10 are stopped, and the piston 26 is lowered with the clamp 10 closed as shown in FIG. Thereby, the wire 6
Is cut at the distal end side of the wire insertion hole 25, and the wire 6 is cut into the remaining wire portion 6B remaining in the wire insertion hole 25 and the ball portion 6A. Then, the ball portion 6A of the cut wire 6 is connected to the semiconductor element 14 by the piston 26.
Of the electrode pad 14A.

At this time, the semiconductor element 14 is previously heated to, for example, about 400 ° C. by a heater (not shown) provided below the XY table 4. Therefore, the ball portion 6A is moved by the piston 26 to the electrode pad 14A.
Electrode pad 1 by the action of temperature, pressure, etc.
4A.

Finally, with the clamp 10 closed, the clamp 10 and the head member 21 are raised from the electrode pad 14A of the semiconductor element 14, as shown in FIG. As a result, the ball portion 6A joined to the electrode pad 14A is separated from the head member 21, and a bump 31 having a projection shape is formed.

Thus, according to the present embodiment, since the head member 21 is provided with the piston 26 that presses the ball portion 6A of the wire 6, the ball portion 6A provided on the distal end side of the wire 6 is pressed by the piston 26. be able to.
Therefore, a sufficient pressing force required for joining can be applied to the ball portion 6A. As a result, the bump 3 having a height substantially equal to the height H2 of the opening 24 provided on the front end side of the head member 21 while maintaining a high bonding strength.
1 can be formed, and the height dimension of the bump 31 can be, for example, about twice as large as that of the conventional technique.
As a result, a sufficient gap can be ensured between the semiconductor element 14 and the substrate 16, so that the resin material can be easily sealed in this gap, and the productivity can be improved.

The piston 26 cuts the wire 6 and cooperates with the opening 24 of the head member 21 to remove the ball 6A of the wire 6 from the electrode pad 14A of the semiconductor element 14.
Therefore, the bumps 31 are separated from the electrode pads 14A in comparison with the case where the wire 6 is cut by pulling the wires 6 upward by the clamp 10 or the like after the ball portion 6A is joined to the electrode pads 14A as in the related art. The force in the direction of movement does not act. For this reason, the bonding strength of the bump 31 can be increased as compared with the related art.

Further, since a suction device 28 is provided near the tip of the head member 21, the tip of the wire 6 is cut by the piston 26 so that the tip end of the wire 6 is located in the middle of the piston sliding hole 22 which is located at the back of the opening 24. Even when it is located, the distal end of the wire 6 can be guided and protruded to the distal end side of the head member 21 by the suction device 28. Further, since an electrode 29 is provided at the opening end of the concave portion 28B of the suction device 28, suction is performed by the suction device 28 and the concave portion 28B is sucked.
Discharge can be generated by the electrode 29 toward the wire 6 that has entered the inside of B, and the ball portion 6A can be formed on the distal end side of the wire 6.

Next, FIG. 10 shows a second embodiment of the present invention. The feature of this embodiment is that a vibration generator for generating ultrasonic vibration is attached to the head holding arm. Note that, in the present embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

Reference numeral 41 denotes a vibration generator attached to the base end side of the head support arm 11. The vibration generator 41 ultrasonically moves the head member 21 together with the head support arm 11 in, for example, the left and right directions in FIG. It vibrates.

The vibration generator 41 operates when the head member 21 descends toward the semiconductor element 14 and presses the ball portion 6A with the piston 26.
Thereby, the bonding strength between the ball portion 6A and the electrode pad 14A of the semiconductor element 14 can be increased. Since the ball portion 6A and the electrode pad 14A are joined by the ultrasonic vibration of the vibration generator 41 in addition to the pressing of the head member 21 and the piston 26, the heating temperature of the semiconductor element 14 is reduced to, for example, about 180 ° C. Can be. For this reason, the bump bonding apparatus according to the present embodiment can be applied to the semiconductor element 14 that is weak to a high temperature of, for example, 180 ° C. or more, and the bump 31 having a high height can be formed while maintaining high bonding strength. .

In each of the above embodiments, the swing arm 27 is provided so as to be able to move horizontally in the left and right directions. For example, the swing arm 27 is provided in the left and right directions and also in the upward and downward directions. It is also possible to adopt a configuration in which the suction device 28 is movably provided so that the suction device 28 is in contact with the distal end side of the head member 21 when the wire 6 is suctioned.

[0054]

As described above, according to the first aspect of the present invention, since the piston is provided in the head portion, the distal end side of the wire can be pressed by the piston. For this reason, a sufficient pressing force required for joining can be applied to the distal end side of the wire. As a result, a bump having a high height can be formed while maintaining a high bonding strength, and a sufficient gap can be secured between the semiconductor element and the substrate. It can be enclosed, and productivity can be improved.

According to the second aspect of the present invention, the piston cuts the wire and presses the tip end of the wire against the electrode pad in cooperation with the opening of the head member. No force acts in the direction of peeling from the electrode pad, and the bonding strength of the bump can be increased.

According to the third aspect of the present invention, since the suction device for sucking the wire is provided near the tip of the head member, the tip of the wire is cut by the piston so that the tip of the wire is located deep in the opening. Even when it is located, the tip of the wire can be guided to the tip of the head by the suction device.

According to the fourth aspect of the present invention, since the suction device is provided with an electrode for generating a discharge at the tip end of the wire, the suction device suctions the electrode and directs the electrode toward the wire protruding near the suction device. As a result, a discharge can be generated, and a spherical ball portion can be formed on the distal end side of the wire.

Further, according to the fifth aspect of the present invention, since the head member is provided with the vibration generating means for generating the ultrasonic vibration, the bonding strength between the tip of the wire and the electrode pad can be increased. Further, since the tip of the wire and the electrode pad are joined by the vibration generating means, the heating temperature of the electronic component can be reduced. Therefore, bumps can be formed even with heat-sensitive electronic components, and the range of applicable electronic components can be expanded.

[Brief description of the drawings]

FIG. 1 is a front view showing a bump bonding apparatus according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a head member of the bump bonding apparatus according to the first embodiment, as viewed from the direction of arrows II-II in FIG.

FIG. 3 is a front end side of the head member according to the first embodiment;
It is a principal part expanded sectional view which expands and shows a suction apparatus etc.

FIG. 4 is a sectional view showing a head member, a swing arm, a semiconductor element, and the like in a state where a piston is raised.

FIG. 5 is a cross-sectional view showing a state where a wire is sucked by a suction device.

FIG. 6 is a cross-sectional view showing a state where a ball portion is formed at the tip of a wire.

FIG. 7 is a cross-sectional view showing a state where a head member is lowered and a ball portion contacts an electrode pad of a semiconductor element.

FIG. 8 is a cross-sectional view showing a state where a piston is lowered and a ball portion is pressed against an electrode pad of a semiconductor element.

FIG. 9 is a cross-sectional view showing a state where a head member is raised and bumps are formed on electrode pads of a semiconductor element.

FIG. 10 is a front view showing a bump bonding apparatus according to a second embodiment.

FIG. 11 is a front view showing a conventional bump bonding apparatus.

FIG. 12 is an explanatory diagram showing a state in which a semiconductor element on which bumps are formed is connected to a substrate.

FIG. 13 is a cross-sectional view showing a head member of a conventional bump bonding apparatus as viewed from the direction of arrows XIII-XIII in FIG. 11;

FIG. 14 is an enlarged cross-sectional view of a main part of a head member according to the related art, which shows a front end side thereof in an enlarged manner.

[Explanation of symbols]

 Reference Signs List 6 wire 6A ball portion 14 semiconductor element (electronic component) 14A electrode pad 21 head member 22 piston sliding hole 24 opening 25 wire insertion hole 26 piston 27 swing arm 28 suction device 29 electrode 31 bump 41 vibration generator (vibration generator) )

Claims (5)

[Claims] 1. A wire supply means for supplying a wire for forming a bump on an electronic component, and a head for forming a bump by pressing a tip end of the wire supplied from the wire supply means against an electrode pad of the electronic component. A bump bonding apparatus comprising: a head member provided with a piston for pressing a tip end of the wire toward the electrode pad; 2. The head member has an opening which is tapered and opened at an end surface on the tip end side of the head member and opens to press the tip end side of the wire against the electrode pad. A wire insertion hole through which the wire is inserted to guide the wire into the opening; and the piston has a remaining wire portion that is a distal end side of the wire guided from the wire insertion hole toward the opening. 2. The bump bonding apparatus according to claim 1, wherein the tip of the wire is pressed against the electrode pad in cooperation with the opening. 3. 3. The bump bonding apparatus according to claim 2, further comprising a suction device that is moved forward and backward with respect to a tip end side of the head member, wherein the suction device sucks a wire from the opening. 4. The bump bonding apparatus according to claim 3, wherein the suction device is provided with an electrode for generating a discharge at a tip end of the wire. 5. The bump bonding apparatus according to claim 1, wherein said head member is provided with vibration generating means for generating ultrasonic vibration.