JPH05160202A - Bonding tool and bonding method - Google Patents

Abstract

(57) [Summary] [Purpose] Without increasing the size of the bonding tool,
An object of the present invention is to perform good bonding to the bonded site without bending the lead even if the lead and the bonded site are misaligned. A bonding tool 10 for pressing and joining leads one by one to a site to be bonded by a pressing surface 10a, wherein the pressing surface 10a is formed into a square having a side orthogonal to the lead. In addition, the length of one side is formed to be larger than the width of the lead.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bonding tool and a bonding method for, for example, single point bonding between each electrode pad of a semiconductor chip and each inner lead of a film carrier.

[0002]

2. Description of the Related Art A single point bonding method has been devised as a bonding method for surely and uniformly connecting a large number of leads provided at a narrow pitch and a corresponding portion to be bonded.

This single point bonding method specifically uses a needle-shaped bonding tool 1 (capillary) and, for example, as shown in FIG. 4, an inner lead 3 (lead) of a film carrier 2 is used. -D) and the electrode pads 5 (bonded portions) of the semiconductor chip 4 are individually connected one by one.

That is, in this single point bonding method, first, the front end portions of the inner leads 3 of the film carrier 2 and the electrode pads 5 of the semiconductor chip 4 are positioned to face each other. Next, after the bonding tool 1 is made to face above the electrode pad 5,
The bonding tool 1 is lowered and the inner lead 3 is pressure-bonded to the electrode pad 5.

At this time, as shown in FIG. 5, if the inner lead 3 and the electrode pad 5 are accurately positioned, the center of the tip portion of the bonding tool 1 becomes
Since it is located on the center line of the outer lead 3, the outer lead 3 can be pressed uniformly, as shown by the diagonal lines in FIG.

[0006]

By the way, when the electrode pad 5 and the inner lead 3 are aligned with each other, a processing error of the inner lead 3 and a relative position between the film carrier 2 and the semiconductor chip 4 are required. The alignment error has an overall effect.

For this reason, as shown in FIG. 6 (a), the inner lead 3 and the electrode pad 5 are misaligned, and the inner lead 3 is not always located at the center of the bonding tool 1. -It may not be possible to press the door 3.

In this case, the inner lead shown in FIG.
As shown in (b), since the inner lead 3 is not pressed symmetrically with respect to the center line, it may be distorted on one side and bent in the lateral direction. This inner
When the battery 3 is bent in the lateral direction, the inner leads 3 and 3 adjacent to each other may come into contact with each other, resulting in poor conductivity.

This problem can be solved by increasing the area of the tip end surface of the bonding tool 1.
As described above, since the semiconductor chips 4 have a narrow pitch, there is a limit in increasing the area.

The present invention has been made in view of such circumstances, and even if there is a misalignment between the lead and the portion to be bonded, the lead is bent at the portion to be bonded. It is an object of the present invention to provide a bonding tool and a bonding method capable of performing good pressure bonding without the use.

[0011]

A first means of the present invention is a bonding tool for pressing and joining leads one by one to a bonded portion by a pressing surface, the pressing surface being the above-mentioned. It is characterized in that it is formed in a rectangular shape having a side intersecting with the lead, and the side intersecting with the lead is formed longer than the width of the lead.

The second means is a bonding method in which a lead is pressed against a portion to be bonded and pressure-bonded, and a side intersecting with the lead is formed to be at least longer than the width of the lead. Using a bonding tool having a rectangular pressing surface, after positioning the lead and the bonding portion facing each other, the pressing surface of the bonding tool is positioned facing the bonding target portion,
The pressing surface is characterized in that the leads are pressure-bonded one by one to the bonding target portion.

[0013]

According to this structure, even if the lead is displaced from the bonding portion, the lead can be pressed uniformly.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to FIGS.
Will be described. The same components as those of the conventional example are designated by the same reference numerals and the description thereof will be omitted.

FIG. 1 shows a bonding tool 1 according to the present invention.
It is an enlarged view of the tip portion of 0. The pressing surface 10a of the bonding tool 10 is square and flat.

The length of one side of the pressing surface 10a is substantially the same as the diameter of the pressing surface of the conventional bonding tool 1 shown in FIGS. 4 and 5, and is at least larger than the width of the inner lead 3. Largely formed.

This bonding tool 10 is attached to the tip of an ultrasonic horn 11 of the bonding apparatus shown in FIG. 4 with its axis line vertical as in the conventional bonding tool 1. There is. In this bonding apparatus, each inner lead 3 of the film carrier 2 (lead) and each electrode pad 5 of the semiconductor chip 4 (bonding portion) are paired by the same operation as the conventional example. Single point bonding will be performed one by one.

According to this structure, as shown in FIG. 6 (a), the electrode pads 5 ...
Even if the center parts of the bonding tool 10 cannot be pressed on the center line e of the inner lead 3 as shown in FIG. 2, the inner parts of the inner parts 3 ... -The lead 3 can be pressed substantially uniformly (symmetrically with respect to the center line). Therefore, the above inner reel
Since the cord 3 is less likely to bend, it is possible to obtain a good product without defective conduction.

Further, in this bonding tool 10, the length (width) of one side of the pressing surface 10a is substantially the same as the diameter of the pressing surface of the conventional bonding tool 1, and therefore the bonding tool 10 is used. It is possible to improve the bonding performance without increasing the size, and it is possible to sufficiently cope with the narrowing of the pitch of the semiconductor chip 4. It should be noted that the present invention is not limited to the above-described embodiment, but can be variously modified without changing the gist of the invention.

For example, although the pressing surface 10a of the bonding tool 10 has a square shape in the above embodiment, the shape is not limited to this and may be a rectangular shape.

That is, in the case of a semiconductor device in which terminals project in four directions like the semiconductor chip 4 shown in FIG.
It is desirable that the inner lead 3 has a square shape because the projecting direction of the inner lead 3 changes by 90 degrees. However, when the inner lead 3 has only two opposing projecting directions, it may have a rectangular shape. In short, the pressing surface 1 of this bonding tool 10
It is sufficient that the length (width) of the side of 0a that intersects (in this embodiment, is orthogonal) the inner lead 3 is at least equal to or greater than the width of the inner lead 3.

Further, in the above-described embodiment, the bonding tool 10 is applied to the inner lead bonding apparatus, but it may be applied to the outer lead bonding apparatus.

In this case, as shown in FIG.
A lead frame 12 is placed below the bonding tool 10 attached to the frame 11 ', and the film carrier 2 is placed on the upper surface of the lead frame 12 (substrate).
The TAB component 13 (semiconductor chip 4) punched from is positioned and mounted.

The outer lead bonding apparatus includes the outer leads 14 ... (Lead) of the TAB component 13,
Each of the terminals 15 (bonding portions) of the wiring pattern of the lead frame 12 is individually joined one by one.

With such a construction, the above outer layer
There is a processing error in the tab 14 ...
Even if there is an error in the positioning between the lead frame 12 and the lead frame 12,
Since the outer lead 14 can be pressed substantially uniformly, good outer lead bonding can be performed as in the case of the inner lead bonding.

[0026]

As described above, the first structure of the present invention is a bonding tool for pressing and joining the leads one by one to the bonded portion on the pressing surface.
The pressing surface is formed in a rectangular shape having a side intersecting with the lead, and the side intersecting with the lead is formed longer than the width of the lead.

The second configuration is a bonding method in which a lead is pressed against a bonding site and pressure-bonded, and a side intersecting the lead is formed to be at least longer than the width of the lead. Using a bonding tool having a rectangular pressing surface, after positioning the lead and the bonding portion facing each other, the pressing surface of the bonding tool is positioned facing the bonding target portion,
The pressing surface is used to press the leads one by one onto the bonded portion.

According to this structure, even if there is a misalignment between the lead and the portion to be bonded without increasing the size of the bonding tool, the lead is attached to the portion to be bonded. Good bonding can be performed without bending.

[Brief description of drawings]

FIG. 1 is an enlarged perspective view of a bonding tool showing an embodiment of the present invention.

FIG. 2 is a plan view showing a bonding process.

FIG. 3 is a perspective view showing another embodiment.

FIG. 4 is a perspective view showing single point bonding.

FIG. 5 is a plan view showing a bonding process of a conventional example.

6A and 6B are plan views of the same.

[Explanation of symbols]

3 ... Inner lead (read), 5 ... Electrode pad (bonding site), 10 ... Bonding tool, 10a
... Pressing surface, 14 ... Outer lead (lead), 15 ... Terminal (bonding site).

Claims (2)

[Claims] 1. A bonding tool for pressing and joining leads one by one on a pressing surface against a site to be bonded, wherein the pressing surface is formed in a rectangular shape having a side intersecting with the lead. And a side crossing the lead is formed longer than the width of the lead. 2. A bonding method in which a lead is pressed against a part to be bonded and pressure-bonded, wherein a rectangular pressing surface is formed such that a side intersecting the lead is at least longer than a width of the lead. After the positioning of the lead and the bonding portion is performed by using the bonding tool which is provided, the pressing surface of the bonding tool is positioned so as to face the bonding target portion, and the lead surface is aligned with the pressing surface. A bonding method, characterized in that the bonding is performed on each of the bonded parts one by one.