JPH07283262A - Wire bonding device - Google Patents

Abstract

PURPOSE:To enable a wire bonding device to surely carry out a wire bonding operation at a higher speed by pa method wherein an XY table which moves a capillary in the directions of X, Y is composed of a a first table and a second table both prescribed in structure. CONSTITUTION:A table 11 on which a work where a wire is bonded is placed, a capillary 13 which is supported above the table 11 in a movable manner that it descends to the surface of the work and capable of letting out a bonding wire 13a from its lower end, and an XY table 14 which moves the capillary 13 in directions of X and Y are included in a wire bonding device 10, wherein the XY table 14 is composed of a first table 15 which moves the capillary 13 from a first bonding position to a second bonding position and a second table 16 which is supported in a movable manner that it moves in the directions of X, Y to the first table 15 and capable of carrying out only a reverse operation at bonding.

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 an upper surface of a semiconductor chip or the like mounted on a lead frame to a contact portion formed on the surface of the lead frame with a bonding wire. It is a thing.

[0002]

2. Description of the Related Art Conventionally, such a wire bonding apparatus is constructed, for example, as shown in FIG. That is,
In FIG. 4, a wire bonding apparatus 1 includes a table 2 fixed to a bonding head (not shown), a torch unit 3 protruding above the table 2, and a torch unit 3.
The capillaries 4 are supported above the torch unit 3 so as to be capable of descending.

Further, the capillary 4 can be moved in the XY directions by an XY table (not shown).

According to the wire bonding apparatus 1 thus constructed, the substrate 5 provided with the semiconductor chip 5a is first placed on the table 2, and from this state, the capillary 4 becomes an XY table. The bonding wire made of gold or the like, which is brought to a first bonding position (for example, a position indicated by symbol A in FIG. 4) by the movement, and which protrudes downward from the lower end thereof at a position higher than the torch unit 3 by a predetermined distance. By discharging between the tip of the bonding wire 4a and the torch unit 3, an initial ball 4b is formed at the tip of the bonding wire 4a.

Subsequently, the capillary 4 is lowered to the surface height of the semiconductor chip 5a, and the capillary 4
However, by pressing the initial ball 4b at the tip of the bonding wire 4a against the semiconductor chip 5a, the initial ball 4b can be pressure-bonded to the semiconductor chip 5a.

Thereafter, the capillary 4 is raised while feeding the bonding wire 4a upward, and is brought to a second bonding position (for example, a position indicated by a symbol B in FIG. 4) by moving the XY table. To be done.

Next, the capillary 4 is lowered to the surface height of the substrate 5, and the capillary 4 presses the bonding wire 4a against the substrate 5, so that the bonding wire 4a is moved to the substrate 5. Can be crimped onto. Thus, one wire bonding process is completed.

Here, the capillary 4 is raised from the first bonding position A, as shown in FIG.
By moving in the horizontal direction, further lowering it, and bringing it to the second bonding position, a bonding wire shape as shown in FIG. 6 is obtained. In this case, since the capillary 4 is moved straight from the first bonding position to the second bonding position by the distance L, the bonding speed is high.

However, in such a movement of the capillary 4 (hereinafter referred to as a normal mode), when the capillary 4 horizontally moves from the first bonding position to the second bonding position, the bonding wire is moved to the second bonding position. In some cases, the wire height is low, and the tip edge may come into contact with the chip edge.

Therefore, when the capillary 4 moves upward from the first bonding position A, as shown in FIG. 7, the capillary 4 is moved slightly away from the XY table in the direction opposite to the second bonding position B. After returning by ΔL once,
A method is known in which the capillary 4 is moved horizontally while moving downward toward the second bonding position B to move it in an arc shape to the second bonding position B. This method is called reverse mode.
The shape of the bonding wire as shown in FIG.

[0011]

However, in the reverse mode in such a wire bonding apparatus 1, since the capillary 4 is once reversed in the direction opposite to the second bonding position, the bonding speed is relatively high. In addition to the problem of being late, the shape of the bonding wire is unreasonable, so that the bonding at the second bonding position may be lost.

In view of the above points, the present invention has as its object the provision of a wire bonding apparatus in which wire bonding can be performed at a higher speed and reliably.

[0013]

According to the present invention, the above object is to provide a table on which a work to be wire-bonded is placed, and above the table, the work surface is supported movably up and down and from the lower end. A capillary having a bonding wire that can be extended downward, and an XY table for moving the capillary in XY directions,
In a wire bonding apparatus, the XY table is a first table that moves a capillary from a first bonding position to a second bonding position during bonding, and a XY table that is supported movably in the XY directions with respect to the first table and reverses during bonding. It is characterized in that it is composed of a second table that only operates,
This is achieved by a wire bonding device.

[0014]

According to the above construction, when the capillary is raised from the first bonding position, the reverse is performed by the movement of the second table of the XY table, and the capillary is moved from the first bonding position to the second bonding position. When moving horizontally to the position, the movement is performed by the first table of the XY table. Therefore, the horizontal movement is performed only by the first table of the XY table.

As a result, the reverse operation is separated into the second table of the XY table, and the first table is
Since the capillary is moved from the first bonding position to the second bonding position, the same high bonding speed as in the conventional normal mode can be obtained.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below based on the embodiments shown in the drawings. FIG. 1 shows an embodiment of a wire die bonding apparatus according to the present invention. In FIG. 1, a wire bonding apparatus 10 includes a table 11 fixed to a bonding head (not shown), a torch unit 12 projecting above the table 11, and a descent support above the torch unit 12. And a capillary 13 that has been formed.

Further, the capillary 13 can be moved in the XY directions by the XY table 14, and the supporting arm 14a is moved around the rotary shaft 14b of the XY table 14 by a swinging device (not shown). By being rocked, it can move in the vertical direction.

The above-mentioned structure is similar to the conventional wire bonding apparatus 1 shown in FIG. 4, but in the wire bonding apparatus 10 according to the embodiment of the present invention, the XY table 14 has a two-stage structure. That is, it is composed of the first table 15 and the second table 16 provided on the first table 15.

Here, like the conventional XY table, the first table 15 of the XY table 14 is horizontally moved by the driving means 17 in order to move the capillary 13 from the first bonding position to the second bonding position. It can be moved in the direction. In the illustrated case, the driving means 17 is composed of a ball screw 17b which is driven to rotate by a motor 17a on the table 11, and a nut portion 17c which is attached to the first table 15 and is screwed to the ball screw 17b. However, any other configuration may be used as long as the first table 15 can be moved in the XY directions.

The second table 16 can be moved horizontally on the first table 15 by the driving means 18 in order to reverse the capillary 13. In the illustrated case, the driving means 18 includes a ball screw 18b which is rotationally driven on the first table 15 by a motor 18a, and a second table 16.
And a nut portion 18c that is attached to the ball screw 18b and is screwed into the ball screw 18b.
Other configurations may be used as long as can be moved in the XY directions.

As a result, the capillary 13 is horizontally moved from the first bonding position to the second bonding position by the first table 15 and is moved upward from the first bonding position when the second table 16 is moved. Reverse operation will be performed.

The wire bonding apparatus 10 according to the embodiment of the present invention is configured as described above. First, the substrate 19 provided with the semiconductor chip 19a is placed on the table 11, and from this state, XY When the first table 15 of the table 14 is moved in the horizontal direction by the driving device 17, the capillaries 13 are brought to the first bonding position (for example, the position indicated by reference symbol A in FIG. 1) and the torch unit 12 is moved. At a position higher by a predetermined distance, the tip of the bonding wire 13a made of gold or the like protruding downward from the lower end and the torch unit 1
An electric ball 13b is formed on the tip of the bonding wire 13a by discharging between the bonding ball 13 and the wire 2.

Then, the capillary 13 is lowered to the surface height of the semiconductor chip 19a, and the capillary 13 presses the initial ball 13b at the tip of the bonding wire 13a against the semiconductor chip 19a. The initial ball 13b can be pressure bonded to the semiconductor chip 19a.

Next, the capillary 13 moves upward, and at the same time, the second operation of the second table 16 of the XY table 14 causes the reverse operation. At this time, the capillary 13 is moved horizontally by the movement of the first table 15 of the XY table 14, and the substrate 19 is moved.
It is brought to the second bonding position (for example, the position indicated by reference character B in FIG. 1) by being lowered to the surface height.

As a result, the capillary 13 presses the bonding wire 13a against the substrate 19 so that the bonding wire 13a can be pressed onto the substrate 19. Thus, one wire bonding process is completed.

Here, as shown in FIG. 2, for example, the capillary 13 moves from the first bonding position A, then moves in the horizontal direction, and at the same time, is lowered to the second bonding position B in an arc shape. Be brought. At this time, the capillary 13 is raised from the first bonding position A and at the same time, the second table 1 of the XY table 14 is moved.
By the movement of 6, the reverse operation is performed as shown by the dotted line in FIG. Thus, the bonding wire shape as shown in FIG. 3 is obtained. At this time, since the second table 15 of the XY table 14 performs the reverse operation of the capillary 13, the wire bonding can be surely performed without pulling the bonding wire 13a.

In this case, since the reverse operation of the capillary 13 is performed only by moving the second table 16 of the XY table 14, the movement of the capillary 13 from the first bonding position to the second bonding position is The first table 15 of the XY table 14 moves horizontally straight without performing reverse operation,
Done. Therefore, the movement of the capillary 13 from the first bonding position to the second bonding position can be performed at a relatively high bonding speed equivalent to that in the conventional normal mode.

[0028]

As described above, according to the present invention, the reverse operation of the capillary is separated into the second table of the XY table, and the first table of the XY table is
Since the capillary is moved from the first bonding position to the second bonding position, the same high bonding speed as in the conventional normal mode can be obtained.

Further, since the capillary is reversed by the second table of the XY table, the wire bonding can be surely performed without pulling the bonding wire.

Thus, according to the present invention, it is possible to provide an extremely excellent wire bonding apparatus which enables wire bonding to be performed at higher speed and reliably.

[Brief description of drawings]

FIG. 1 is a schematic side view showing the configuration of an embodiment of a wire bonding apparatus according to the present invention.

FIG. 2 is a trajectory diagram showing the movement of the capillaries in the wire bonding apparatus of FIG.

FIG. 3 is an enlarged view showing a shape of a bonding wire by the wire bonding apparatus of FIG.

FIG. 4 is a schematic side view showing an example of a conventional wire bonding apparatus.

5 is a locus diagram showing movement of capillaries in a normal mode of the wire bonding apparatus of FIG. 4. FIG.

6 is an enlarged view showing the shape of a bonding wire by moving the capillary of FIG.

7 is a trajectory diagram showing movement of the capillaries in the circular interpolation-reverse mode of the wire bonding apparatus of FIG.

8 is an enlarged view showing the shape of a bonding wire by moving the capillary of FIG.

[Explanation of symbols]

 10 Wire Bonding Device 11 Table 12 Torch Unit 13 Capillary 14 XY Table 14a Support Arm 15 First Table 16 Second Table 17 Drive Device 18 Drive Device 19 Substrate 19a Semiconductor Chip

Claims (1)

[Claims] 1. A capillary having a table on which a work to be wire-bonded is placed, a capillary having a bonding wire supported above the table so as to be movable up and down to the surface of the work and extending downward from a lower end, and the capillary. A XY table for moving in the XY directions, a wire bonding apparatus, wherein the XY table moves a capillary from a first bonding position to a second bonding position during bonding, and the first table. And a second table that is movably supported in the XY directions and that only performs a reverse operation during bonding.