JPH05226401A - Wire guide and wire bonding device using the same - Google Patents

Abstract

PURPOSE:To contribue to simplification and quickness of a wire passing work in a bonding tool. CONSTITUTION:A gas jetting device 41, which jets out gas almost in parallel with the tangential direction of the virtual circle 50 having the tube center of a bonding tool 7 as the center, is provided in the vicinity of the wire receptacle part of the bonding tool 7. A guide wall is formed by the above-mentioned jetting gas, and a wire 9 is effectively guided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wire bonding apparatus for connecting a semiconductor component (IC chip) as a component to be bonded and a lead by using a bonding tool to carry out a bonding connection, and particularly to a wire bonding device. The present invention relates to a wire bonding apparatus capable of smoothly introducing a wire into the hollow portion of the bonding tool so that the bonding work can be rapidly continued when the wire is broken.

The present invention also relates to a wire guide device to be installed in the wire bonding device.

[0003]

2. Description of the Related Art Conventionally, in order to perform a bonding connection between a pad of an IC chip and a lead using this type of wire bonding apparatus, a generally cylindrical capillary as a bonding tool provided at the tip of a bonding arm. Then, the wire is held and brought into contact with the surface of the target pad or lead, and a part of the wire having a ball formed at the tip thereof is crushed using the capillary and thermocompression-bonded to weld. At this time, ultrasonic vibration may be applied to the tip of the wire at the same time.

The process of performing this wire bonding is shown in FIG.
0 will be described with reference to FIG. 0. When attempting to wire bond to a pad (electrode) on the IC chip 25 mounted on the bonding stage 26, the capillary 7 through which the wire 9 having a ball formed at the tip is inserted is illustrated. After positioning by moving an XY table (not shown) based on information from an image pickup device (not shown), the capillary 7 is lowered as shown in FIG. To do.

In this step, → moves the bonding arm (not shown) downward at a high speed, and → moves it at a low speed. At this time, the clamp 8a is open.
Next, when the connection to this first bonding point is completed,
In →, the bonding arm is raised in the upward direction shown in FIG. 10, that is, the Z-axis direction while the clamp 8a is in the open state, and the wire 9 is pulled out with the clamp 8a in the open state as shown in accordance with a predetermined loop control. Is connected to the lead 27 which is the second bonding point.

After this connection, the clamp 8a is closed while the wire 9 is pulled out from the tip of the capillary 7 by a predetermined feed amount f as shown by. In this state, the wire 9 is cut as shown in the process of further raising the bonding arm 1 to a predetermined height, and a ball is formed again at the tip of the wire using an electric torch (not shown), and the clamp 8a is attached. Return to the open state. Wire bonding is performed by such a series of steps.

In the above-mentioned conventional wire bonding apparatus, the wire 9 may break and come out of the capillary 7 for some reason during bonding, and in order to continue the bonding work, the broken wire is inserted into the capillary. It should be noted that the operator appropriately performs this. Further, although the wire 9 is wound around a spool (not shown), when the wire is replaced with a new spool, the work of inserting the wire into the capillary 9 is similarly performed.

[0008]

However, in such a conventional device, since the wire 9 is extremely thin, it is difficult to handle, and in a normal state where no tension is applied, it is twisted to some extent. There is a drawback that the work of inserting it into the capillary 7 is not always easy,
Therefore, the operator feels awkward and has a problem to be solved in order to improve the efficiency of the bonding work.

Therefore, the present invention has been made in view of the above-mentioned drawbacks of the prior art, and provides a wire guide device and a wire bonding device equipped with the wire guide device, which contributes to simplification and speed-up of the wire insertion work into the capillary. It is an object.

[0010]

According to the present invention, in a wire guide device for guiding a supplied wire in a predetermined direction, a gas is ejected substantially parallel to a tangential direction of an imaginary circle which is substantially perpendicular to the direction to be guided. It is configured so as to have a gas ejecting means. Further, the present invention is a wire bonding apparatus for bonding with a wire inserted into a hollow portion of a substantially cylindrical bonding tool attached to a tip of a bonding arm, wherein the bonding tool is arranged near a wire receiving portion of the bonding tool. The tool is configured to have a gas ejecting means for ejecting gas substantially parallel to the tangential direction of an imaginary circle centered on the cylinder center of the tool.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a wire bonding apparatus as an embodiment of the present invention will be described with reference to the accompanying drawings. In the following description, the same reference numerals are used for the same or corresponding members as those of the conventional device shown in FIG.

FIG. 1 shows a main part of a wire bonding apparatus according to the present invention, and FIG. 2 is a sectional view taken along line AA of FIG.

In this wire bonding apparatus, as shown in FIG. 1, a bonding arm 1 composed of a holding frame 1a and a horn 1b can swing together with a swing arm 2 around an axial center of a support shaft 3. The bonding arm 1 is firmly fitted to the support shaft 3, and the swing arm 2 is swingably fitted to the support shaft 3. The support shaft 3 is mounted on an XY table or the like (not shown). An ultrasonic transducer (not shown) for vibrating the horn 1b is incorporated in the holding frame 1a. A solenoid 4a and an electromagnetic attraction piece 4b are fixed to the swing arm 2 and the holding frame 1a so as to face each other. When swinging the bonding arm 1, a power source (not shown) for the solenoid 4a is provided. The bonding arm 1 and the swing arm 2 are fixedly coupled to each other by energizing them from above to generate an attractive force between them and the electromagnetic attracting piece 4b, but shaking so as not to be attracted for a predetermined distance or more. An adjustable stopper 6 fixed to the moving arm 2 with a screw or the like is provided. Further, the swing arm 2 and the holding frame 1
The magnet 5a is located at a position in front of the electromagnetic attraction means.
And the coil 5b are attached respectively. The magnet 5a and the coil 5b constitute means for generating an attraction force for urging the tip end of the bonding arm 1, that is, the portion holding the capillary 7 as a bonding tool downward in FIG. 2 during bonding.

A clamp arm 8 is provided at the tip of the swing arm 2, and the clamp arm 8 is provided with a clamp opening / closing mechanism 81 composed of a solenoid and a spring as shown in FIG. ing. The clamp opening / closing mechanism 81 is provided with a clamp 8a for gripping and cutting the wire 9. This clamp opening / closing mechanism 8
1, the clamp 8a and the clamp arm 8 constitute a clamp means.

FIG. 3 shows the structure of the clamp opening / closing mechanism 81 in a simplified manner, but as shown in the drawing, the clamp fixing portions 81b ₁ and 8b mounted and fixed to the clamp arm 8 are shown.
A clamp 8a is attached to the tip of 1b ₂ .
The clamp portions 8a ₁ and 8a ₂ of the clamp 8a are configured to be openable and closable in the direction of the arrow, and the clamp portions 8a ₁ and 8a ₂ are provided with an arm 81a that is rotatable about a shaft 81c. It is configured to open and close by rotating in the direction of the arrow. This arm 81a is driven by a solenoid (not shown).

The clamp parts 8a ₁ and 8a ₂ are
The surfaces facing each other are formed as mirror surfaces for holding the wire 9, and are made of, for example, cermet or the like, which has conductivity and is excellent in wear resistance, corrosion resistance, and the like.

An electric torch 10 is disposed below the capillary 7 on a vertical shaft (not shown) so as to be rotatable by the action of an actuator or the like, and is rotated around the capillary 7 as the bonding arm 1 moves. It has a movable structure. This electric torch 10 applies a predetermined voltage to form a ball at the tip of the wire 9. Also, the clamp 8a
Is fixedly supported by a frame (not shown) above, and a predetermined tension is applied to the wire 9 so that the wire 9 is always held straight up to the tip of the capillary 7 of the bonding arm 1 and an opening / closing mechanism (not shown) is provided. A tension clamp 11 that can be opened and closed is provided by the, and the wire 9 is further wound by a spool 36 via a guide 12.

Next, as shown in FIG. 2, the swing arm 2
A support shaft 15a is provided on the rear end side, and the arm side cam follower 15 and the swing base 16a are connected to the support shaft 15a.
It is rotatable around. A bearing guide 16b is fixed to the swing base 16a at one end thereof, and a preload arm 16d is attached to the other end of the bearing guide 16b.
Is rotatably attached via a support pin 16c. A support shaft 17a is provided at a free end of the preload arm 16d, and a cam follower 17 is rotatably attached to the support shaft 17a. And this preload arm 16
A preload spring 16e, which is a tension spring, is wound around the tip of d and the tip of the swing base 16a, and the arm-side cam follower 15 and the cam follower 17 are the outer peripheral surface of the cam 18 formed in a substantially heart shape. Pressed against the cam surface. The two contact points of the arm side cam follower 15 and the cam follower 17 with respect to the cam 18 are located with the center of rotation of the cam 18 in between.

A frame structure is formed by the rocking base 16a, the bearing guide 16b, and the preload arm 16d, and is collectively referred to as a rocking frame 16.
The bearing guide 16b as a component of the swing frame 16 is in contact with the outer ring of the radial bearing 20 attached to the cam shaft 19 to which the cam 18 is fitted. The cam 18 is rotated by the torque applied to the cam shaft 19 by the motor 21. The height position of the capillary 7 as a bonding tool is detected by a rotary encoder (not shown) connected to the support shaft 3.

Next, the wire guide device according to the present invention will be described.

The wire guide device comprises gas ejection means 41 and gas suction means 42 shown in FIGS. The details of the gas ejection means 41 are shown in FIGS. 4 and 5, and the details of the gas suction means 42 are shown in FIG. Hereinafter, first, the configuration of the gas ejection means 41 will be described in detail.

As shown in FIGS. 1 and 3, the gas ejection means 41 is arranged near the wire receiving portion of the capillary 7 as a bonding tool. Then, as shown in FIGS. 3 and 4, the gas ejection means 41 is formed by bending a tubular material, which is made of, for example, metal or resin and has a circular cross-sectional shape, into a rectangular annular shape, and distributes the supplied gas. It has a distribution pipe 44 and, for example, four gas ejection pipes 45 connected to the inner circumference side of the distribution pipe 44 and in the vicinity of the four pipes. As shown in FIG. 3, the distribution pipe 44 is a small bracket 4 fixed to the clamp fixing portion 81b ₂ which is a constituent member of the clamp opening / closing mechanism 81 by a screw or the like at the upper end portion.
It is attached to the lower end of 6.

As is particularly apparent from FIG. 4, the distribution pipe 44
Is provided with a socket portion 44a, and one end of a flexible tube 47 for supplying compressed air which is a gas to be jetted is connected to the socket portion 44a.
The other end of the tube 47 is connected to a compressor or the like (not shown) that is a gas supply source, but is used to supply and disconnect gas between the tube and the gas supply source. A valve (not shown) is interposed.

FIG. 5 is a sectional view taken along the line BB of FIG. 4, but as is particularly clear from the drawing, each gas ejection pipe 45 is fitted in the socket portion 44c fixed to the distribution pipe 44. The distribution pipe 44 is fixedly provided by brazing or the like, and communicates with the internal space of the distribution pipe 44 through a hole 44d formed in the distribution pipe 44. Each of the gas ejection pipes 45 has a nozzle portion 45a (illustrated in FIG. 5) at the tip thereof, and is provided so as to eject gas in different directions. Specifically, as shown in FIG.
Each gas ejection pipe 45 ejects gas in parallel with the tangential direction of an imaginary circle 50 perpendicular to the direction in which the wire 9 should be guided, that is, the imaginary circle centered on the cylinder center of the capillary 7 (see FIG. 3). Are arranged so as to Further, the gas ejection pipes 45 are oriented such that the gas ejection directions of the adjacent nozzles intersect with each other. As is clear from FIGS. 3 and 5, each gas ejection pipe 45 has its gas ejection direction with respect to an imaginary plane (not shown) perpendicular to the cylinder center of the capillary 7. Is inclined toward the wire supply section side.

Next, the structure of the gas suction means 42 will be described in detail. As is apparent from FIG. 3, the gas suction means 42
Is arranged at a position sandwiching the capillary 7 with the gas jetting means 41, that is, on the wire guiding direction side. The gas suction means 42 is attachable to and detachable from the capillary 7, and is attached only when performing a wire insertion operation on the capillary 7, and is detached from the capillary 7 during the bonding operation and accommodated at a predetermined position. Has been done.

As shown in FIGS. 3 and 6, the gas suction means 42 comprises a hollow case 52 and a locking member 53 fixed to the upper end of the outer case 52. As is apparent from FIG. 6, the upper end of the case 52 has a tapered surface 7a formed on the tip of the capillary 7, that is, on the outer periphery of the pointed portion.
A suction hole 52a is formed in a tapered shape so that the suction hole 52a can be fitted in. A socket portion 52b is provided on the outer peripheral portion of the case 52 near the lower end portion, and one end of a flexible tube 54 for sucking gas is connected to the socket portion 52b. The other end of the tube 54 is connected to a vacuum pump or the like (not shown) that sucks gas. Further, a valve (not shown) for sucking gas and disconnecting the gas is interposed between the tube 54 and the vacuum pump.

On the other hand, the locking member 53 provided on the case 52 is for locking the gas suction means 42 to the capillary 7 when the gas suction means 42 is used, and is made of, for example, rubber or synthetic resin. The material preferably has a sponge-like structure, and is locked by being externally fitted to the capillary 7 with a frictional force.

In the wire bonding apparatus having the above-described structure, wire breakage occurs during the bonding work, or the wire 9 is no longer stored in the spool 36 (shown in FIG. 1).
If the wire comes out of b (shown in Figure 6),
The wire is reintroduced into the capillary 7 using the wire guide device described above, and the bonding operation is continued. The wire reinsertion operation when all the wires wound on the spool 36 are used is performed when a new spool is attached in place of the used spool.

When re-inserting the wire into the capillary 7, first, as shown in FIGS. 3 and 6, an operator attaches the gas suction means 42 to the capillary 7. Specifically, as shown by the chain double-dashed line in FIG. 6, the gas suction means 42 is brought directly under the capillary 7, and then moved upward as shown by the arrow, and the locking member provided in the gas suction means 42 is provided. 53 is fitted into the capillary 7, and the hole 52a of the case 52 is fitted into the tapered surface 7 of the capillary 7.
Fit to a. After that, each valve (not shown) is opened in order to supply the gas to the gas ejection means 41 (illustrated in FIG. 3 and the like) and suck the gas by the gas suction means 42. Then, as shown by the arrow in FIG. 4, gas is ejected from each gas ejection pipe 45 included in the gas ejection means 41, and is simultaneously sucked by the gas suction means 42, and as shown in FIG. 3 and FIG. It becomes a conical vortex flow 56 and flows into the gas suction means 42 through the hollow portion 76 of the capillary 7. Therefore, this vortex 56 acts as a guide wall that effectively guides the wire 9, and the wire insertion work into the hollow portion 7b of the capillary 7 can be performed easily and quickly.

As shown in FIG. 5, since the jetting direction of the gas jetting pipe 45 of the gas jetting means 41 is inclined toward the wire supply side, the spiral vortex flow 56 is generated by the component force based on this inclination. Is encouraged. Further, the wire guiding means includes both a gas ejecting means 41 for ejecting a gas and a gas sucking means 42 for sucking the gas, but the gas ejecting means 41 alone can perform a certain guiding action. It is possible to generate a wall. Gas suction means 4
By providing 2 as well, the vortex 56 as described above is generated, and the effect of guiding the wire 9 is enhanced.

FIG. 7 and FIG. 8 show the gas ejection means 61, which is the main part of the wire guiding means as the second embodiment of the present invention.

As shown in the figure, the gas ejection means 61 is
It has a single gas ejection pipe 62 formed in an annular shape as a whole. The gas ejection pipe 62 is formed by connecting a pair of inner and outer divided bodies 62a and 62b to each other by brazing or the like, and the cross-sectional shape of the pipe is, for example, circular. In this embodiment, a pair of inner and outer divided bodies 62a, 6a
Although the gas ejection pipe 62 is formed by 2b, it may be formed by a pair of upper and lower divided bodies. In addition, the gas ejection pipe 6
Although 2 is formed in a circular ring shape as a whole, various other shapes such as a rectangular ring shape, a triangular ring shape, and a C-shape in which a part of the ring is cut out can be adopted.

The socket portion 6 is provided on the outer peripheral portion of the gas ejection pipe 62.
2c is provided, and one end of the flexible tube 63 for supplying the gas to be jetted is provided with the socket 62.
connected to c. The other end of the tube 63 is connected to a gas supply source such as a compressor (not shown). Further, a valve (not shown) for supplying and disconnecting gas is interposed between the tube and the compressor or the like.

As shown in the figure, for example, four nozzle portions 62d are provided at equal pitches on the inner peripheral portion of the gas ejection pipe 62, that is, on the inner divided body 62a. The details of the nozzle portion 62d are shown in FIG. And
Each of the nozzle portions 62d is formed so as to be directed in different directions. Specifically, as shown in FIG. 8, each nozzle portion 62d has a virtual circle 65 perpendicular to the direction in which the wire 9 is to be guided, that is, a virtual circle centered on the center of the tube of the capillary (see FIG. 3). It is oriented to eject gas parallel to the tangential direction. Further, the nozzle portions 62d are oriented such that the gas ejection directions of the adjacent nozzle portions intersect with each other.

As shown in FIG. 7, even when the gas jetting means 61 having the above-mentioned structure is used, the vortex 56 is generated by jetting and sucking the gas, as in the wire guiding means as the first embodiment described above. However, the wire 9 can be smoothly introduced into the capillary 7 (illustrated in FIG. 3 and the like).

[0036]

As described above, according to the present invention,
The gas ejected from the gas ejecting means acts as a guide wall for effectively guiding the wire, and the wire insertion work into the capillary can be performed easily and quickly, which contributes to the improvement of the work efficiency.

[Brief description of drawings]

FIG. 1 is a side view of a main part of a wire bonding apparatus according to the present invention including a partial cross section.

FIG. 2 is a cross-sectional view taken along line AA of FIG.

FIG. 3 is a perspective view including a partial cross-section showing a wire guiding device as a first implementation side included in the wire bonding device shown in FIG. 1 and a mechanism around the wire guiding device.

4 is a plan view including a partial cross section of the gas ejection means provided in the wire guide device shown in FIG.

5 is a cross-sectional view taken along line BB in FIG.

6 is a side view including a partial cross section of the gas suction means included in the wire guide device shown in FIG.

FIG. 7 is a perspective view of a gas ejection unit included in a wire guide device according to a second embodiment of the present invention.

8 is a plan view of the gas jetting means shown in FIG. 7 including a partial cross section.

9 is an enlarged view of a portion C in FIG.

FIG. 10 is an explanatory diagram showing a bonding process of a conventional wire bonding apparatus.

[Description of References] 1 Bonding arm 7 Capillary (bonding tool) 7b Hollow part 36 Spool 41, 61 Gas ejection means 42 Gas suction means 44 Distribution pipe 45, 62 Gas ejection pipe 50, 65 Virtual circle 52 Case 53 Locking member 56 Whirlpool

Claims (7)

[Claims] 1. A wire guide device for guiding a supplied wire in a predetermined direction, comprising a gas ejecting means for ejecting gas substantially parallel to a tangential direction of an imaginary circle substantially perpendicular to the direction to be guided. A wire guide device characterized by the above. 2. The wire guide device according to claim 1, further comprising a gas suction unit which is arranged on the wire guide direction side with respect to the gas ejection unit and sucks the gas. 3. A wire bonding apparatus for bonding with a wire inserted into a hollow portion of a substantially cylindrical bonding tool attached to a tip of a bonding arm, the wire bonding apparatus being arranged near a wire receiving portion of the bonding tool. A wire bonding apparatus comprising a gas ejection means for ejecting gas substantially parallel to a tangential direction of an imaginary circle centered on a cylinder center of a bonding tool. 4. The wire bonding apparatus according to claim 3, further comprising a gas suction unit disposed between the gas jetting unit and the bonding tool so as to sandwich the bonding tool. 5. The gas jetting direction by the gas jetting means is inclined toward the wire supply portion side of the bonding tool with respect to an imaginary plane perpendicular to the cylinder center. The wire bonding apparatus according to claim 4. 6. The gas jetting means is provided with a plurality of gas jetting pipes each having a nozzle portion provided so as to jet in different directions. The wire bonding apparatus according to any one of the above. 7. The gas jetting means has a gas jetting pipe having a plurality of nozzle portions formed in an annular shape or a substantially annular shape and arranged in the inner peripheral portion so as to be oriented in mutually different directions. The wire bonding apparatus according to any one of claims 3 to 5.