JPH04324948A - Bonding method and tool - Google Patents

Abstract

PURPOSE:To prevent an inner lead from deviating from a bump electrode enhancing the bonding of them to each other in bonding strength so as to obtain the bonding of high reliability between them. CONSTITUTION:A protrusion 5 whose inner side is tapered is provided to each of the four corners of the top face of a bonding tool 6a, the bonding tool 6a is brought into contact with an inner lead 4 which is liable to get out of position if it is bent, to press the inner lead 4 against a bump electrode 3 correcting the bend of the lead 4 for bonding.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to TAB (Tape
The present invention relates to a bonding method and tool for bonding a lead formed on an automated bonding (Automated Bonding) type semiconductor device to an electrode pad on an IC chip placed in a hole in a film.

0002

2. Description of the Related Art FIG. 3 is a plan view showing a TAB type semiconductor device, and FIG. 4 is a diagram showing an example of a conventional wire bonding apparatus. Generally, in a TAB type semiconductor device, as shown in FIG. It is a structure connected to 4.

The wire bonding device used to bond the bump electrode and the inner lead includes a clamper 11 that clamps and holds the film 7, as shown in FIG.
A chip pedestal 8 on which the IC chip 1 is placed, a bonding tool 6 that presses and joins the ion leads and bump electrodes, and a position detection camera 10 that images the surface of the IC chip 1 and recognizes the position of the bump electrodes. have.

FIGS. 5(a) to 5(c) are partial side views of the vicinity of a bonding tool shown in the order of steps for explaining an example of a conventional bonding method and its tool. When bonding a bump electrode and an inner lead using the wire bonding apparatus described above, first, as shown in FIG. 5(a), the bonding tool 6 is positioned above the portion where the inner lead 4 and the bump electrode 3 overlap. do.

Next, as shown in FIG. 5B, the bonding tool 6 is lowered from above the bump electrodes 3 and inner leads 4 on the heated IC chip 1, and while the inner leads 4 are deformed, as shown in FIG. As shown in (c), the inner leads 4 are pressed against the bump electrodes 3 on the IC chip 1, and a predetermined load is applied to bond them by thermocompression. In this way, all the inner leads and bump electrodes were bonded by repeatedly moving the bonding tool 6 up and down and positioning the inner leads 4 and bump electrodes 3.

[0006]

[Problem to be solved by the invention] Figures 6(a) and (b)
1 is a partial side view showing the vicinity of a bonding tool shown in the order of steps for explaining problems in a conventional bonding method and the tool. However, in the conventional bonding method and its tool, when trying to press the inner lead 4 with the bonding tool 6, as shown in FIG.
If a misalignment with the bonding tool 6 occurs, the bump electrode 3 and the inner lead 4 will be bonded with the misaligned position. This may cause the bump electrode 3 and the inner lead 4 to separate, resulting in a decrease in bonding strength, or a short circuit between the misaligned inner lead and an adjacent bump electrode or an adjacent inner lead, etc. There is a problem in that reliability and yield are lowered.

SUMMARY OF THE INVENTION An object of the present invention is to provide a bonding method and tool that can reliably hold and bond inner leads to bump electrodes in order to solve this problem.

[0008]

[Means for Solving the Problems] The bonding method of the present invention is a bonding method in which one end of a plurality of inner leads formed on a film is bonded to a bump electrode of a semiconductor chip, in which positional deviation occurs due to bending of the tip. The method is characterized in that the inner lead is pressed and bonded to the bump electrode while being drafted. Further, the bonding tool of the present invention has protrusions having inwardly inclined surfaces at the four corners of the tip surface.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be explained with reference to the drawings. FIGS. 1A and 1B are a side view and a perspective view showing the main parts of a bonding apparatus for explaining a bonding method and tool thereof according to an embodiment of the present invention. As shown in FIG. 1, the shape of the bonding tool 6a of this bonding device is such that the tip surface thereof is slightly larger than the bump electrode 3, and the four corners of the tip surface have projections 5 having inwardly tapered portions.
This is because we have established the following.

FIGS. 2(a) to 2(c) are side views showing the vicinity of a bonding tool in order of steps for explaining the bonding method of the present invention. Next, a method for bonding inner leads and bump electrodes using the bonding apparatus shown in FIG. 1 will be described. First, as shown in FIG. 2(a), the bonding tool 6a is positioned on the inner lead 4. Next, as shown in FIG. 2(b), the bonding tool 6a is lowered, and when the bonding tool 6a approaches the inner lead 4, the lowering speed is slightly lowered to bring the tip end surface of the bonding tool 6a into contact with the inner lead 4. let At this time, even if the inner lead 4 is misaligned with the bonding tool 6a, the taper portion of the protrusion 5 follows and the inner lead 4 is fitted between the protrusions 5. Next, as shown in FIG. 2C, the inner leads 4 are pressed against the bump electrodes 3 of the IC chip 1 using the bonding tool 6a to securely bond the inner leads 4 and the bump electrodes 3.

[0011]

As explained above, the present invention provides protrusions with inwardly tapered parts at the four corners of the tip surface of the bonding tool, and presses the inner leads against the bump electrodes while correcting the inner leads that have been misaligned due to bending. Bonding has the effect that sufficient bonding strength can be obtained, and a bonding method and tool thereof with high bonding reliability can be obtained.

[Brief explanation of drawings]

1(a) is a side view and FIG. 1(b) is a perspective view showing the main parts of a bonding apparatus for explaining a bonding method and a tool thereof according to an embodiment of the present invention; FIG.

FIG. 2 is a partial side view of the vicinity of a bonding tool showing the process order for explaining the bonding method and tool of the present invention.

FIG. 3 is a plan view showing a TAB type semiconductor device.

FIG. 4 is a diagram of an example of a conventional bonding apparatus.

FIG. 5 is a partial side view of the vicinity of a bonding tool showing the process order for explaining an example of a conventional bonding method.

FIG. 6 is a partial side view of the vicinity of a bonding tool showing the process order for explaining problems of a conventional bonding method and the tool.

[Explanation of symbols]

1 IC chip 3 Bump electrode 4 Inner lead 5 Protrusion 6, 6a Bonding tool

Claims (2)

[Claims] 1. In a bonding method in which one end of a plurality of inner leads formed on a film is bonded to a bump electrode of a semiconductor chip, the inner lead is bonded to the bump electrode while correcting the inner lead which is misaligned due to bending of the tip. A bonding method characterized by pressure bonding. 2. A bonding tool characterized by having protrusions having inwardly inclined surfaces at the four corners of the tip surface.