JPH03178142A - Wire bonding equipment - Google Patents

Abstract

PURPOSE:To prevent the generation of rotation angle deviation between the axial direction of a wire hole and that of a wire, and improve the reliability and the yield of products using the wires, by constituting a wedge in the manner in which the surface shape intersecting perpendicularly to the axial direction is polygonal. CONSTITUTION:The shape of surface S, of a wedge 9, intersecting perpendicularly to the axial direction is polygonal, e.g. triangular. As a result, when the wedge 9 is fixed to a horn 6 with a screw, the rotation angle deviation is not generated between the axial direction of a wire hole 9a and that of a wire 11, so that, at the time of bonding process, the damage of the wire 11 and the generation of whiskers caused by the contact of the side wall of the wire 11 and that of the wire hole 9a can be prevented. Thereby the strength decrease of the wire 11 caused by the damage of the wire 11 and the short circuitting between adjacent wires caused by the whiskers formed on the wire 11 can be prevented. Hence the reliability and the yield of a semiconductor integrated circuit can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to wire bonding technology, and particularly to a technology that is effective when applied to an ultrasonic wire bonding device.

[Conventional technology]

Regarding ultrasonic wire bonding equipment that performs wire bonding processing using ultrasonic waves and pressure, for example, see Applied Technology Publishing Co., Ltd., November 3, 1985, "
Recent semiconductor assembly technology and its high reliability and full automation are described in JP156-P161 and P322-P323.

The ultrasonic wire bonding device applies ultrasonic vibrations transmitted from an ultrasonic vibrator to a wedge tool (hereinafter simply referred to as wedge) to a bonding wire (hereinafter simply referred to as wire) supplied to the tip of the wedge. This is a bonding device that performs wire bonding processing.

FIG. 5 shows a wedge of a conventional ultrasonic wire bonding device. The wedge 50 is a tool that applies ultrasonic vibrations amplified through a horn 51 to a wire 52 supplied to the tip of the wedge 50, and is fixed to the end of the horn 51 with a screw 53. By the way, as shown in the figure, conventionally, in the wedge 50, the shape of the surface S perpendicular to the axial direction has been semicircular.

[Problem to be solved by the invention]

However, the present inventor found that the above conventional technology has the following problems.

That is, in the conventional ultrasonic wire bonding apparatus, since the wedge has a semicircular surface perpendicular to the axial direction, the wedge 50 is fixed with a screw 53 as shown in FIG. 6, for example. At this time, the wedge 50 moves in the direction of rotation shown by the arrow, and as shown in FIG. There was a problem that a deviation of the angle θ occurred.

If a rotation angle misalignment occurs between the axial direction of the wire hole and the axial direction of the wire, the wire will come into contact with the side wall of the wire hole during the bonding process, resulting in scratches and scratches on the surface. . As a result, problems such as a decrease in the mechanical strength of the wire and short-circuiting between adjacent wires occur, resulting in a significant decrease in the reliability and yield of products using the wire.

The present invention has been made in view of the above problems, and its purpose is to provide a technology that can improve the reliability and yield of products using wire.

The above and other objects and novel features of the present invention will become apparent from the description of the specification and the accompanying drawings.

[Means to solve the problem]

A brief overview of typical inventions disclosed in this application is as follows.

That is, the invention according to claim 1 is a wire bonding apparatus that performs a wire bonding process by applying vibration energy supplied from a vibrator to a wire via a wedge, and in which the wire bonding process is performed in the axial direction of the wedge. The wire bonding device has a structure in which perpendicular surfaces are polygonal.

[Effect]

According to the invention described in claim 1, for example, when screwing the wedge into the horn, the wedge does not shift in the direction of rotation around its axis, so that the axial direction of the wire hole and the axis of the wire There is no rotational angle deviation between the two directions.

〔Example〕

FIG. 1(a) is a perspective view showing a wedge and a horn of a wire bonding apparatus according to an embodiment of the present invention, FIG. Figure 1 (C) is a front view of this wedge and horn, Figure 1 (A) is a sectional view of the wedge and horn,
FIG. 2 is a plan view of the wedge for explaining processing setting conditions for this wedge, and FIG. 3 is a perspective view of the wire bonding apparatus.

The wire bonding apparatus of this embodiment is an ultrasonic wire bonding apparatus used, for example, in the assembly process of semiconductor integrated circuit devices.

As shown in FIG. 3, an ultrasonic wire bonding device 1
includes a time control circuit 2, an ultrasonic oscillator 3, an ultrasonic vibrator 4, a cone 5, a horn 6, and a wire spool 7.
, wire clamp 8, wedge 9, and sample holder 1
0 is provided.

The time control circuit 2 is a circuit section that controls the oscillation frequency oscillated by the ultrasonic oscillator 3.

The ultrasonic vibrator 4 is a converter that converts electrical energy of a predetermined oscillation frequency supplied from the ultrasonic oscillator 3 into ultrasonic vibrations.

A cone 5 and a horn 6 joined to one end of the ultrasonic vibrator 4 are an amplifying section that amplifies the ultrasonic vibrations supplied from the ultrasonic vibrator 4.

The wire spool 7 is a wire accommodating portion that stores a wound wire 11 made of gold (Au), aluminum (A1), or the like. The wire 11 is connected to a wire hole 6a drilled in the horn 6 from the wire spool 7 and a wire hole 9a drilled in the wedge 9 (see FIG. 1(a)), which will be described later.
and FIG. 2) to the tip of the wedge 9. The diameter of the wire 11 is, for example, 38
It is about μm. Further, the diameter of the wire hole 9a bored in the wedge 9 is, for example, about 80 μm.

The wire clamp 8 holds the wire 11 after the bonding process.
This is a wire cutting section that cuts the wire.

The sample holder IO is a table on which a sample to be subjected to wire bonding processing is placed, and in this embodiment, for example, the package substrate 12 is placed thereon.

A semiconductor chip 13 on which a predetermined integrated circuit is formed is mounted on the package substrate 12 . semiconductor chip 13
Although not shown, a plurality of bonding pads are formed on the outer periphery of the upper surface of the package substrate 12 , and these bonding pads and electrode pads formed on the package substrate 12 are connected by wires 11 . The distance between each bonding pad is, for example, about 100 to 150 μm.

The wedge 9 is fixed to the end of the horn 6 with a screw 14, as shown in FIGS. 1(a) to 1(d).

In this embodiment, the wedge 9 has a triangular surface S that is perpendicular to the axial direction. Therefore, the ultrasonic wire bonding apparatus 1 of this embodiment
The structure is such that when the wedge 9 is screwed to the horn 6, there is no deviation in rotational angle between the axial direction of the wire hole 9a drilled at the tip of the wedge 9 and the axial direction of the wire 11.

Further, as shown in FIG. 2, the wedge 9 has an apex angle opposite to the side on the screw fixing side among the corners of the surface S, which is connected to the wire hole 9a.
The shape is precisely machined so that it is located on the axial direction line 15 of. Further, the shape of the hole drilled in the horn 6 for inserting the wedge 9 is also triangular, and the apex angle opposite to the side on the screw fixing side is located on the ring direction line of the wire 11 (not shown). It is precisely machined and formed. Therefore, in the ultrasonic wire bonding apparatus 1 of this embodiment, when the wedge 9 is inserted into the hole drilled in the horn 6,
The axial line 15 of the wire hole 9a of the wedge 9 and the wire 1
It has a structure in which the axial direction line of No. 1 coincides with high precision.

In this way, the ultrasonic wire bonding apparatus 1 of this embodiment
According to the publication, in the wedge 9, the shape of the surface S perpendicular to the axial direction is triangular, so that when the wedge 9 is screwed to the horn 6, the axial direction of the wire hole 9a and the axial direction of the wire 11 are aligned. Since no rotational angle deviation occurs between the bonding processes, it is possible to prevent damage to the wire 11 and generation of whiskers due to contact between the side wall of the wire 11 and the side wall of the wire hole 9a during the bonding process. As a result, it is possible to prevent problems such as a decrease in the strength of the wire 11 due to damage to the wire 11 and a short between adjacent wires 11 due to whiskers formed on the wire 11, thereby improving the reliability of the semiconductor integrated circuit device. It becomes possible to significantly improve the yield.

In addition, when processing the wedge 9, among the corners of the triangular surface S, the apex angle opposite to the side on the screw fixing side is set to the wire hole 9a.
The shape is precisely machined so that it is located on the axial direction line 15 of
In addition, when machining the hole drilled in the horn 6 to insert the wedge 9, the apex angle of the corner of the triangular hole opposite to the side on the screw fixing side is placed on the axial line of the wire 11 (not shown). By accurately processing and forming the wedge 9 so that it is located at , when the wedge 9 is attached to the horn 6, the axial line 15 of the wire hole 9a of the wedge 9 and the axial line of the wire 11 match with high precision. , wedge 9 with high precision,
Moreover, it can be easily attached to the horn 6.

As above, the invention made by the present inventor has been specifically explained based on Examples, but it should be noted that the present invention is not limited to the Examples and can be modified in various ways without departing from the gist thereof. Not even.

For example, in the embodiment described above, the wedge has a triangular surface shape perpendicular to the axial direction, but it is not limited to this and various modifications can be made. For example, as shown in FIG. ).

As shown in (c), the shape of the surface S perpendicular to the axial direction of the wedge 9 may be a quadrilateral. The wedge 9 is accurately machined so that the center line of the side of the surface S opposite to the side on the screw fixing side is located on the axial line 15 of the wire hole 9a (see FIG. 2). Further, the shape of the hole drilled in the horn 6 for inserting the wedge 9 is also square, and the center line of the side opposite to the side on which the screw is fixed is the wire 1.
It is precisely machined so that it is located on the axial direction line of 1 (not shown). Therefore, in this case as well, it is possible to obtain the same effects as in the above embodiment.

〔Effect of the invention〕

Among the inventions disclosed in this application, the effects obtained by typical inventions are briefly described below.

That is, it is a wire bonding apparatus that performs a wire bonding process by applying vibration energy supplied from a vibrator to a wire via a wedge, and the wedge has a polygonal surface shape perpendicular to the axial direction. According to the invention described in claim 1, for example, when screwing the wedge into the horn, there is no rotational angle deviation between the axial direction of the wire hole and the axial direction of the wire, so that the wire and the wire hole are It is possible to prevent damage to the wire and generation of whiskers due to contact with the side wall, and it is possible to improve the reliability and yield of products using the wire.

[Brief explanation of drawings]

FIG. 1(a) is a perspective view showing a wedge and a horn of a wire bonding apparatus according to an embodiment of the present invention, FIG. 1(b) is a plan view showing a surface shape of the wedge perpendicular to the axial direction, and FIG. Figure 1 (C) is a front view of this wedge and horn, Figure 1 (Company) is a sectional view of the wedge and horn, Figure 2 is a plan view of the wedge explaining the processing setting conditions of this wedge, and Figure 31! I is a perspective view of the wire bonding device, 1
! Fig. 4(a) is a perspective view showing a wedge and a horn of a wire bonding device according to another embodiment of the present invention, and Fig. 4(b) is a perspective view showing a direction perpendicular to the axial direction of the wedge shown in Fig. 4(a). FIG. 5 is a perspective view showing a wedge and a horn of a conventional wire bonding device; FIG. 6 is a plan view showing a wedge and a screw for fixing the wedge in a conventional wire bonding device; FIG. 7 FIG. 2 is a plan view of a wedge illustrating a rotational angle deviation of the wedge in a conventional wire bonding apparatus. DESCRIPTION OF SYMBOLS 1... Ultrasonic wire bonding device, 2... Time control circuit, 3... Ultrasonic oscillator, 4... Ultrasonic vibrator, 5... Cone, 6... Horn, [3a. ... wire hole, 7 ... wire spool, 8 ... wire clamp, 9 ... wedge, 9a ... wire hole, 10.
... Sample holder, 11... Wire, 12... Package board, 13... Semiconductor chip, 14... Screw,
15... Axial direction line, S... Surface, 50... Wedge, 51... Horn, 52... Wire, 52a, 54
a... Axial direction, 53... Screw, 54... Wire hole.

Claims (1)

[Claims] 1. A wire bonding device that performs a wire bonding process by applying vibration energy supplied from a vibrator to a bonding wire via a wedge tool, wherein the wedge tool A wire bonding device characterized by having orthogonal surfaces having polygonal shapes. 2. The wire bonding apparatus according to claim 1, wherein the surface shape is triangular. 3. The wire bonding apparatus according to claim 1, wherein the surface shape is a square.