JPS6335098B2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to automatic wire bonders.

In the assembly of integrated circuit devices, etc., there is a wire bonding process in which the electrodes of pellets (circuit elements) fixed to the substrate are connected to the inner ends of the leads using wires. As shown, the positional relationship between the pellet 2 fixed on the substrate 1 and the lead 3 is detected (recognized) by electrical and optical means such as a television camera 4, a television 5, and an arithmetic device (not shown), and the bonding process is performed to hold the wire 6. An automatic wire bonder that automatically performs wire bonding by controlling a tool 7 is known. In addition, the board (e.g. lead frame)
1 is a guide 9 sequentially from the cartridge 8 on the loader side.
The wire bonding is carried out on the stage 10 directly below the bonding tool 7 when the wires are stopped, and then moved on the guide 11 again to be sequentially stored in the cartridge 12 on the unloader side.

By the way, the substrate 1 sent to the stage 10
In this case, as shown in FIGS. 2a and 2b, there are some cases in which the pellet 2 is not fixed partially.
This occurs when pellets are not supplied during pellet bonding, or when pellets are not attached due to a bonding error. Traditionally, when this situation occurs,
Since the pellet is not detected (recognized), the wire bonder automatically stops as a recognition failure.

On the other hand, among the stoppages of the wire bonder due to poor pellet recognition, there is a large misalignment of the pellet attachment position, and automatic wire bonding may be possible by manually positioning the pellet.

However, in the case of the above-mentioned pellet attachment failure (hereinafter referred to as the condition in which the pellet is not fixed to the board), the operator moves the board one pitch without positioning it and restarts the wire bonder. However, the operating rate will decrease.

Therefore, an object of the present invention is to improve the operating rate of a wire bonder.

The gist of the present invention to achieve such an object is to automatically detect the relative positional relationship between the pellets and the inner ends of the leads of a board having pellets and leads that are sequentially fed onto a stage, and to determine the wire bonding position. After that, an automatic wire bonder that connects each electrode of the pellet and the inner end of the lead with a wire detects whether or not the pellet is fixed on the board, and if not, the board is wire bonded. An automatic wire bonder is characterized in that the wire is passed over a stage without being bonded. The present invention will be explained below with reference to Examples.

FIG. 8 is a schematic diagram of an automatic wire bonder according to an embodiment of the present invention. This automatic wire bonder has a pellet presence detection mechanism attached to the automatic wire bonder shown in Fig. 1, and performs wire bonding when a pellet is attached to the board (lead frame). The wire bonding is continued by moving the lead frame 1 one pitch without performing bonding. That is, the nozzle 14 of the pellet presence/absence detection mechanism 13 is disposed one position (one pitch) before the wire bonding position, and is adapted to face the pellet 2 on the lead frame 1. This nozzle 14 is connected to a compressor mechanism 16 connected via a pipe 15, and when the compressor mechanism 16 operates, gas is sprayed from the tip of the nozzle 14 onto the pellets 2 on the lead frame 1, and the back of the nozzle is The pressure is automatically detected (the pressure display is carried out by a gauge 17). Compared to the state where the pellet 2 is fixed to the lead frame 1,
When the pellet 2 is not fixed to the lead frame 1, the back pressure decreases as the obstruction moves away from the nozzle. Therefore, since the presence or absence of pellets is recognized based on the presence or absence of this back pressure drop, this signal system is sent to the control section (not shown) of the wire bonder, and the part of the lead frame where the pellet is defective is moved to the stage (bonding position; (The lead frame may be long and thin so that several pellets can be placed on it. In this case, it will be the bonding position.) It is moved without stopping at 10, and the lead frame part to which the next or the next pellet is fixed stops at the stage (bonding position). wire bonding continues. This eliminates the need for the wire bonder to stop due to poor pellet attachment, improving the operating rate.

Note that the present invention is not limited to the above embodiments. That is, as shown in FIG.
Light 19 is irradiated onto the upper pellet 2 from the projector 18 diagonally above, and the reflected light 20 is sent to the receiver 21.
The presence of the pellet may be recognized by receiving the reflected light 20, and the absence of the pellet may be recognized by not receiving the reflected light 20.

Further, the pellet presence/absence detection mechanism may have a structure other than that described above. However, since the pellet is fragile and has a bonding pad on its surface and the active area is expanding, it is not desirable for the detection part to come into contact with it, so a non-contact type pellet presence detection mechanism is used. something is required.

As described above, the automatic wire bonder of the present invention has
Since the machine does not stop even if there is a pellet attachment failure, the operating rate of the automatic wire bonder is improved and work efficiency is improved.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing an outline of a conventional automatic wire bonder, FIGS. 2 a and b are front views of a lead frame with a pellet attached poorly, and FIG. 3 is a schematic diagram of an automatic wire bonder according to an embodiment of the present invention. FIG. 4 is a schematic diagram showing a pellet presence/absence detection mechanism according to another embodiment of the present invention. 1...Substrate, 2...Pellet, 3...Lead,
4...TV camera, 5...TV camera, 6...
... wire, 7 ... bonding tool, 8 ... cartridge, 9 ... guide, 10 ... stage,
11...Guide, 12...Cartridge, 13...
... Pellet presence/absence detection mechanism, 14... Nozzle, 15
... Pipe, 16 ... Compressor mechanism, 17
... Gauge, 18 ... Floodlight, 19 ... Light, 20
...Reflected light, 21... Light receiver.

Claims (1)

[Claims] 1 After automatically detecting the relative positional relationship between the pellets and the inner ends of the leads of the substrate having the leads and the pellets that are sequentially fed onto the stage and determining the wire bonding position, each electrode of the pellet and the inner end of the leads are In an automatic wire bonder that connects the substrate with a wire, it is detected whether or not a pellet is fixed on the substrate, and if not, the substrate is passed over the stage without wire bonding. Automatic wire bonder with special features.