JP2517005B2 - Wire bonding tools - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Overview] Regarding a bonding tool of a wire bonder for wedge-bonding a wire, an end surface of a tip constitutes a wire pressing surface with an object of increasing an inclination near a second bonding point of the wire. On the side opposite to the wire supply side to the wire pressing surface, there is provided an inclined surface which is inclined and rises from the pressing surface and which is provided with a vacuum suction port.

[Industrial applications]

The present invention relates to a wire bonding tool of a wire bonder for wedge bonding wires.

The wire bonder is a device used for connecting the electrodes of the semiconductor chip attached to the package to the inner leads of the package with a wire, and the wire bonding tool is a part for bonding the wire. Further, the wedge bonding has a feature that the electrodes and the like can be downsized because the bonding area is small.

[Conventional technology]

FIG. 3 is a side view for explaining wedge bonding.

In FIG. 1, a wire bonding tool (hereinafter, abbreviated as a tool) 1 has a wire feeding nozzle 2 arranged so as to be always located beside one side surface thereof, and a wire 3 fed below an end surface of a tip, Bonding by pressing on the connection target. The connection target is, for example, the semiconductor chip 4
The electrode 5 and the inner lead 7 of the package 6. Further, the wire 3 is an aluminum wire or the like having a diameter of about 20 to 30 μm, and there is a case where slight sliding is applied during the pressing.

That is, the tool 1 presses the tip of the wire 3 against the electrode 5 to perform the first bonding, moves the wire 3 from the nozzle 2 in an arc to the position of the inner lead 7, and moves in the middle of the wire 3. The wire 3 is pressed by the lead 7 to perform the second bonding, and then the wire 3 is cut at the nozzle 2 side by separating the wire 3 from the inner lead 7 while the nozzle 2 clamps the wire 3.
Make a connection between.

Here, when the package 6 has a structure indicated by a chain double-dashed line and interferes with the nozzle 2 during the second bonding, the bonding order is reversed from the above and the first bonding target is the inner lead. 7, the target of the second bonding is the electrode 5. Regarding this order, the former is generally called forward bonding and the latter is called reverse bonding.

By the way, if the conventional example of the tool 1 used in this way is the tool 10, the main part of the tool 10 is shown in the side view of FIG.

In the figure, 11 is a tool main body, 12 is a wire pressing surface configured by an end surface of the tip of the tool main body 11 to press the wire 3,
Reference numeral 13 is a guide hole for obliquely guiding the wire 3 supplied from the nozzle 2 to the wire pressing surface 12.

The cutting of the wire 3 described above occurs between the wire pressing surface 12 and the guide hole 13, and the tip of the wire 3 after cutting remains in the guide hole 13, so that the next first bonding can be performed smoothly. It can be carried out.

[Problems to be solved by the invention]

However, in the second bonding when this tool 10 is used, as shown in FIG. 5, the inclination of the wire 3 entering from the first bonding point to the second bonding point in the vicinity of the second bonding point becomes small, so that the electrode 5 When the reverse bonding is performed on the semiconductor chip 4 having the wiring 5a exposed to the outside, the wire 3 may come into contact with the wiring 5a, which causes a problem of reducing the reliability of the product.

[Means for solving problems]

The problem is that the end face of the tip constitutes the wire pressing face,
The problem is solved by using the tool of the present invention, which comprises a bevel facing away from the wire feed side to the wire push face, which is ramped up from the wire push face and provided with a vacuum suction port.

[Action]

Due to the presence of the slope provided with the vacuum suction port, the wire extending from the wire pressing surface to the slope side rises along the slope when the wire pressing surface presses the wire.

Therefore, the inclination of the wire entering the second bonding point from the first bonding point in the vicinity of the second bonding point becomes large, the occurrence of the above-mentioned unnecessary contact is prevented, and the reliability of the product is improved.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2. FIG. 1 is a side view (a) and a front view (b) showing an essential part of the embodiment, and FIG. 2 is a side view showing a second bonding using the embodiment, and the same reference numerals are the same throughout the drawings. Indicates an object.

The tool 20 of the embodiment shown in FIG. 1 is used as the tool 1 described above instead of the tool 10 of the conventional example.

In FIG. 1, 21 is a tool body, 22 is a tool body 21.
A wire pressing surface composed of the end surface of the tip for pressing the wire 3, 23 is a guide hole for obliquely guiding the wire 3 supplied from the nozzle 2 to the wire pressing surface 22, and 24 is a wire pressing side opposite to the wire 3 supply side. The slope that rises from surface 22
25 is a vacuum suction port provided on the slope 24, 26 is the suction port, and 27 is a guide wall that stands up on both sides of the slope 24 and guides the wire 3.

In the side view (a) of this tool 20, the right side from the wire pressing surface 22 is the same as the conventional one, and the tool body 21 is on the left side.
The slope 24 is provided by widening the width of the. When targeting an aluminum wire of 30 μmφ, for example, the length of the wire pressing surface 22 is about 50 to 70 μm, and the diameter of the guide hole 23 is 50 to 80 μmφ.
The slope of the slope 24 is about 30 degrees, the projected length of the slope 24 with respect to the extended surface of the wire pressing surface 22 is about 50 to 100 μm, and the slope 2
The inclination of 4 is about 30 to 40 degrees, the width of the slope 24 shown in the front view (b) is about 60 μm, and the vacuum suction port 25 is arranged in the approximate center of the slope 24 and has a size of about 30 μmφ. is there.

Then, in the second bonding when the tool 20 is used, as shown in FIG. 2, the wire 3 that enters the second bonding point from the first bonding point is inclined by the vacuum suction when the tool 20 descends. Along the line, the inclination in the vicinity of the second bonding point is almost the same as the inclination of the slope 24 by being pressed as it is and becomes larger than in the case of the conventional example. Therefore, the electrode 5
Semiconductor chip 4 with wiring 5a exposed outside
When reverse bonding is performed on
The problem that occurred in the conventional example of contacting 5a is eliminated, and the reliability of the product is improved.

The dimensions of each part of the tool 20 are not limited to the dimensions described in the above embodiment, and may be appropriately determined depending on the target wire 3 or the like.

〔The invention's effect〕

As described above, according to the configuration of the present invention, in the bonding tool of the wire bonder for wedge-bonding the wire, a tool for increasing the inclination in the vicinity of the second bonding point of the wire is provided. It has the effect of improving quality.

[Brief description of drawings]

FIG. 1 is a side view and a front view showing an essential part of the embodiment, FIG. 2 is a side view showing a second bonding using the embodiment, FIG. 3 is a side view for explaining wedge bonding, and FIG. FIG. 5 is a side view showing the main part of the conventional example, and FIG. 5 is a side view showing the problems of the conventional example. In the figure, 1, 10 and 20 are wire bonding tools, 3 is a wire, 5 is an electrode (bonding target), 7 is an inner lead (bonding target), 11 and 21 are tool bodies, and 12 and 22 are wire pressing surfaces. , 13 and 23 are guide holes, 24 is a slope, 25 is a vacuum suction port, 26 is a suction hole, and 27 is a guide wall.

Claims (1)

(57) [Claims] 1. A wire bonder bonding tool for wedge-bonding a wire, wherein an end surface of a tip constitutes a wire pressing surface, and a wire pressing side is provided on a side opposite to a wire supply side, inclined from the wire pressing surface, and vacuumed. A wire bonding tool having a slope provided with a suction port.