JPH088276B2 - Wire bonding method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention makes it possible to shorten the overall bonding time by overlapping the bonding work and the bonding position detection in the wire bonding work in IC assembly. The present invention relates to a wire bonding method capable of improving the above.

[Conventional technology]

The detailed structure of the bonding sample before wire bonding in the IC assembly is, for example, as shown in FIG. 3, the IC element 2 is attached on the lead frame 1, and the wire is attached to the lead frame 1 corresponding to the pad 3 of the IC element 2. 5
Leads 4 for bonding connection (see FIG. 5) are formed. Reference numerals 6-1 and 6-2 denote detection marks serving as coordinate reference points of the lead position, which usually require one or two places, and the tip of the lead 4 can be substituted.
FIG. 4 shows a part of the lead frame 1 in which the IC assembly structure as shown in FIG. 1 is continuously arranged at a constant pitch.

5 and 6 show the wire 5 in the IC assembly.
The detailed structure after bonding is shown.

By the way, in this type of wire bonding work, a recognition camera, which is provided with a bonding head and is fixed to a horizontally moving XY table, is moved right above the IC element 2 and the lead 4 to move the pad 3 and the lead 4 together. The position coordinates are recognized and stored, and then wire bonding is performed while moving the bonding head based on the stored position coordinates.

[Problems to be Solved by the Invention]

However, in such a conventional wire bonding work, the lead position recognition work and the bonding work cannot be performed at the same time, and particularly in the case of bonding a large number of pins such as a lead frame, a ceramic package, a carrier board, etc. In many cases, the lead positions must be individually recognized, and the lead position recognition work significantly hinders the bonding workability, making it difficult to improve productivity. there were.

The present invention, except for the above-mentioned conventional drawbacks, improves the workability of the bonding by overlapping the lead position recognition work and the wire bonding work, improves the productivity, and enables wire bonding of good quality. It is intended to provide a method.

[Means for solving the problem]

The present invention is a method for carrying out wire bonding by sequentially transporting a bonding sample having pads and leads to be bonded to a bonding position at a constant pitch, which is different from the XY table at the bonding position at a position one pitch before the bonding position. After the lead position recognition camera fixed on the XY table recognizes and stores the individual lead position coordinates of the bonding sample, the bonding sample is transported to the bonding position and the pad position recognized on the XY table at that position is recognized. In the wire bonding method, the position coordinates of the pad are recognized and stored by the camera, and the above-mentioned stored lead position coordinates are read back to perform bonding.

[Action]

According to the present invention, when the bonding sample is sequentially conveyed to the bonding position at a constant pitch, when the bonding sample is positioned one pitch before the bonding position, the bonding position of the bonding position is changed according to the coordinates of the standard position of the lead stored in advance. XY different from XY table
A lead position recognition camera fixed to the table prompts one or two of the lead coordinate reference points, and then recognizes and stores individual lead position coordinates based on that.

Next, the bonding sample is conveyed by 1 pitch and placed at the bonding position, and the bonding position is adjusted according to the standard coordinates of the standard position of the pad stored in advance.
The pad position recognition camera fixed on the XY table prompts one or two points of the coordinate reference point of the pad and recognizes and stores the position coordinate of the pad based on this, and this is already recognized and stored one pitch before. Read back the position coordinates of all existing leads and perform wire bonding.

During this bonding operation, the individual lead position coordinates of the next bonding sample conveyed one pitch before are recognized and stored as described above, and the operation is repeated.

In this way, the bonding work and the lead position recognition work overlap each other.

〔Example〕

An embodiment of the present invention will be described with reference to the drawings. In FIG. 1, for example, a lead frame as shown in FIG. 4 is used as a bonding sample 10, and a bonding tool 12 is provided on an XY table 11 at a constant pitch. When the lead 4 is conveyed to the bonding stage 14 having the bonding head 13, the individual position coordinates of the lead 4 are obtained at the position of the prestage 15 which is one pitch before the bonding stage 14 based on the coordinate reference point of the lead position. That is, the lead position recognition camera 17 mounted on the XY table 11 and fixed to the XY table 16 that moves horizontally differently from the XY table 11 is used for the lead 4 stored in the recognition storage device 18.
By operating the XY table 16 in accordance with the coordinates of the standard position of the, the detection mark 6-1 or 6-2 which is the coordinate reference point of the lead 4 (the tip of the lead 4 is also acceptable) is prompted. After that, the position coordinates of the individual leads 4 are recognized and stored in the recognition storage device 18.

Next, the bonding sample 10 is conveyed by one pitch and positioned on the bonding stage 14, and the recognition storage device is provided.
According to the standard position coordinates of the pad 3 stored in 18
The XY table 11 is operated, and the pad position recognition camera 19 fixed on the XY table 11 prompts one or two coordinate reference points of the pad 3 (the pad 3 is also possible) to prompt the pad 3
The position coordinates of the pads 3 are recognized and stored in the recognition storage device 18, and then the position coordinates of the pads 3 and the position coordinates of all the leads recognized and stored by the prestage 15 are read back to perform wire bonding by the bonding tool 12. .

That is, in the bonding stage 14, all the corresponding bonding positions of the pad 3 and the lead 4 of the bonding sample 10 are obtained, and the wire bonding is performed.

And during this bonding work,
The position coordinates of all the leads of the next bonding sample 10 conveyed to 15 are recognized and stored as described above, and the bonding work and the lead position recognition work overlap each other.

The reference positional relationship between the lead position recognizing camera 17 and the pad position recognizing camera 19 is 1 of the bonding sample 10.
Set to pitch or correct.

In FIG. 1, 20 is a base frame on which the XY table 11 is mounted, and 21 is a visual ITV.

FIG. 2 shows another embodiment of the present invention, in which the XY table 16 of the lead position recognition camera 17 is provided directly on the base frame 20 separately from the XY table 11, and the XY table is provided.
Although it is possible to perform horizontal movement independently of 11, the stroke of the XY table 16 becomes large, but the movement operation of the lead position recognition camera 17 becomes easy, and wasteful time can be reduced.

〔The invention's effect〕

As described above, according to the present invention, during the wire bonding work, the positions of the bonding points of all the leads to be bonded next are recognized and stored, and the bonding work and the lead position recognition work are performed. Overlapping is performed, and particularly workability of wire bonding of a large number of pins is remarkably improved, good quality wire bonding is possible, and high-speed automation can be facilitated.

[Brief description of drawings]

1 and 2 are explanatory views showing an embodiment of the present invention, FIG. 3 is a plan view showing an example of a bonding sample before IC assembly, and FIG. 4 is a plan view showing a part of a lead frame. 5 is a plan view after wire bonding in FIG. 3, and FIG. 6 is a cross-sectional view taken along the line I-I in FIG. 1 ... Lead frame, 2 ... IC element, 3 ... Pad,
4 ... Lead, 5 ... Wire, 6-1, 6-2 ... Detection mark, 10 ... Bonding sample, 11, 16 ... XY table, 12 ... Bonding tool, 13 ... Bonding head, 14 ... … Bonding stage, 15 …… Prestige, 17 …… Lead position recognition camera, 19 …… Pad position recognition camera, 18 …… Recognition storage device, 20 …… Base frame, 21 …… ITV.

Claims (1)

[Claims] 1. A method of carrying out wire bonding by sequentially transferring a bonding sample having pads to be bonded and leads to a bonding position at a constant pitch, and an XY table at the bonding position at a position one pitch before the bonding position. After the lead position recognition camera fixed on another XY table recognizes and stores the individual lead position coordinates of the bonding sample, the bonding sample is conveyed to the bonding position and the pad position fixed on the XY table at that position. A wire bonding method characterized in that the position coordinates of the pad are recognized and stored by a recognition camera, and this and the stored lead position coordinates are read back to perform bonding.