JPH03263848A - Bonding tool - Google Patents

Abstract

PURPOSE:To simplify a bonding device and to enhance reliability of bonding by providing a recess of a circular shape as seen in a plane on the pressing surface of a tool. CONSTITUTION:In a tool for pressing the end of a lead to the electrode of a semiconductor element and applying an ultrasonic vibration in the direction of the pressing surface to connect the electrode to the lead, a recess 12 of a circular shape as seen in a plane is formed on the pressing surface of the tool. For example, the recess 12 of the circular shape as seen in a plane is provided at the center of the end face of a bonding tool body 11 having an end face of the circular shape as seen in a plane, and the lead is intruded to the recess 12 at the time of applying the vibration. Thus, a tool mounting head is rotated in response to the applying direction of the vibration to eliminate the necessity of altering a tool mounting angle. Even if a small error exists at the tool mounting angle of a head rotating direction, sufficient energy by the vibration can be obtained at the bonding surface of the electrode to the lead.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is directed to TAB (Tape Automation 7D
The present invention relates to a bonding tool suitable for use when bonding an electrode of a semiconductor element and an inner lead of a tape carrier by a bonding method.

[Conventional technology]

Conventionally, this type of bonding tool is shown in Figures 7 and 8.
It is configured as shown in the figure. This bonding tool 1 includes a bonding tool main body 2 having a flat rectangular tip end face in a plan view, and a recess 3 having a semicircular cross section is provided in the center of the end face of the bonding tool main body 2.

Furthermore, conventional bonding tools such as those shown in FIGS. 9 to 11 are also employed. This bonding tool 4 includes a bonding tool main body 5 having a flattened circular end face in a plan view, and a two-cross shaped convex portion 6 is provided on the end face C of this bonding tool main body 5.

As shown in FIG. 12, bonding using the bonding tool configured as described above is performed by attaching a surface to a protruding electrode 7 made of, for example, Au, provided on an electrode (not shown) of a semiconductor element (not shown). The tip of the lead 8 made of Cu plated with Ni-Au or the like is brought into contact with the bonding tool body 25. Next, the tip of the lead 8 is pressed by the bonding tool body 25, and the pressing surface is pressed. This is done by applying ultrasonic vibration in the direction of the arrow (in the plane direction) to promote reaction or solid diffusion between the metal of the lead 8 and the metal of the protruding electrode 7 at the joint 9. At this time, in the bonding tool shown in FIGS. 7 and 8, the lead 8 is placed in the recess 3.
Further, in the bonding tool shown in FIGS. 9 to 11, the convex portion 6 bites into the lead 8, and ultrasonic energy is transmitted to each bonding surface.

[Problem to be solved by the invention]

By the way, in the former (bonding tool shown in FIGS. 7 and 8), the planar shape of the tip surface is 180°.
Since the same shape can be obtained by rotating the
For example, when connecting the Lee 18 to the protruding electrodes 7 arranged in parallel on four sides around a semiconductor element (not shown) as shown in FIG. Accordingly, it has become necessary to change the tool mounting angle by rotating a tool mounting head (not shown). As a result, a rotating mechanism for a tool mounting head (not shown) is required (1), resulting in a problem that the bonding apparatus becomes complicated.

On the other hand, the latter (pumpings shown in Figures 9 to 11)
In this case, since the same shape in plan view of the tip surface can be obtained by rotating 90 degrees, the leads 8 are attached to the protruding electrodes 7 arranged in parallel on the four sides of the semiconductor element (not shown).
When connecting, as mentioned above, there is no need to rotate the tool mounting head (not shown) depending on the direction of application of ultrasonic vibration, but there is a slight error in the tool mounting angle in the direction of head rotation. Then, ultrasonic vibration occurs in the direction shown by the dashed arrow in FIG. 10, and sufficient vibrational energy cannot be applied to the bonding surface between the protruding electrode 7 and the lead 8, resulting in a decrease in bonding reliability. There was an inconvenience.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a bonding tool that can simplify the bonding apparatus and improve the reliability of the bonding ink.

[Means to solve the problem]

A bonding tool according to the present invention is a tool that connects an electrode and a lead by pressing the tip of a lead against an electrode of a semiconductor element and applying ultrasonic vibration in the plane direction of the pressing surface. A recessed portion having a circular shape in plan view is provided on the pressing surface.

[For production]

In the present invention, the shape of the tip end surface of the tool in plan view can always be the same in plan view by rotating the tool around the center axis.

〔Example〕

EMBODIMENT OF THE INVENTION Hereinafter, the structure etc. of this invention will be explained in detail by the Example shown in the figure. Here, the same reference numerals are used for the same members as those explained in FIGS. 7 to 13.

Fig. 1 is an enlarged perspective view of part A in Fig. 4, Fig. 2 is a view taken in the direction of arrow A in Fig. 1, Fig. 3 is a sectional view taken along the ■-m line in Fig. 2, and Fig. 4 is FIG. 1 is a perspective view showing the entire bonding tool according to the present invention. In the same figure, the reference numeral 11 indicates a bonding tool main body having a flat end face that is circular in plan view, and a recess 12 that is circular in plan view is provided in the center of the end face. The lead 8 is configured to bite into the lead 8 when sonic vibration is applied.

In the bonding tool configured in this way,
Since the shape of the tip of the tool in plan view can always be the same in plan view by rotating around the central axis of the tool, for example, as shown in FIG. When connecting the leads 8 to the parallel protruding electrodes 7, the tool mounting head (not shown) is rotated in accordance with the direction of application of ultrasonic vibrations shown by arrows H and l in the figure. There is no need to change the mounting angle, and there is no need for a rotating mechanism for the seal mounting head.

In addition, in this example, the shape of the tool end surface in plan view is always the same as seen in plan view by rotation around the tool center axis, even if there is a slight error in the tool mounting angle in the direction of rotation of the head. , sufficient energy due to ultrasonic vibration can be obtained at the joint surface between the protruding electrode 7 and the lead 8.

Next, a bonding method using a bonding tool, which is an embodiment of the present invention, will be described.

That is, the tip of the lead 8 is brought into contact with the protruding electrode 7,
Next, connect the tip of this lead 8 to the bonding tool body 1.
1, and applying ultrasonic vibration in the plane direction of this pressing surface (in the direction of the arrow in FIG. 2) to promote reaction or solid diffusion between the metal of the lead 8 and the metal of the protruding electrode 7. At this time, the lead 8 bites into the recess 12 and ultrasonic energy is transmitted to the joint surface.

In this embodiment, an example in which the recess 12 having a circular shape in plan view is provided on the tool tip surface is shown, but the present invention is not limited to this, and as shown in FIGS. As shown, a protrusion 21 is provided on the tool tip surface, and this protrusion 21
A recess 22 having a circular shape in plan view is provided in the center of the tool, or a recess 23 having a circular shape in plan view is provided in the center of the tool tip surface as shown in FIGS.
Even if an annular groove 24 extending around the recess 23 is provided, the same effects as in the embodiment can be obtained.

〔Effect of the invention〕

As explained above, the present invention is a tool that connects an electrode and a lead by pressing the tip of the lead against the electrode of a semiconductor element and applying ultrasonic vibration in the plane direction of the pressing surface. Since the pressing surface of this tool is provided with a recessed portion having a circular shape in plan view, the tip end surface of the tool can always have the same shape in plan view by rotating around the central axis of the tool. Therefore, there is no need to change the tool mounting angle by rotating the tool mounting head according to the direction of application of ultrasonic vibration, which eliminates the need for a rotation mechanism for the tool mounting head, simplifying the bonding equipment. It is possible to aim for In addition, the fact that the shape of the tip of the tool in plan view is always the same when rotated around the central axis of the tool means that even if there is a slight error in the tool installation angle in the direction of head rotation, the electrode and lead Since sufficient energy can be obtained from ultrasonic vibration at the bonding surface of the bonding surface, the reliability of bonding can also be improved.

[Brief explanation of drawings]

Fig. 1 is an enlarged perspective view of part A in Fig. 4, Fig. 2 is a view taken along arrow A in Fig. 1, Fig. 3 is a sectional view taken along the line ■■ in Fig. 2,
FIG. 4 is a perspective view showing the entire bonding tool according to the present invention, FIG. 5(a), fb) and FIG. 6(al,
(bl is a plan view and a sectional view showing another embodiment, FIG. 7 is a perspective view showing a conventional bonding tool, and FIG. 8 is a
Figure 9 is a perspective view showing a conventional bonding tool, Figure 10 is a view viewed from arrow C in Figure 9, Figure 11 is a sectional view taken along the line XIXI in Figure 10, and Figure 12 is FIG. 13 is a perspective view for explaining the bonding process, and a plan view showing the bonding state of the electrode and the lead. ]1...bonding tool body, 12...recess. 1 Prisoner 2 Figure 3 Figure 2 Figure 1 Agent Masuo Oiwa Figure J WI6 Figure (0) (b) Figure 12 Figure 10 Figure 11 Figure 13

Claims (1)

[Claims] A tool that connects the electrode and the lead by pressing the tip of the lead against the electrode of a semiconductor element and applying ultrasonic vibration in the plane direction of the pressing surface, the pressing surface of the tool having a A bonding tool characterized by having a circular recess.