JPH06104307A - Mechanism and method for carrying lead frame of wire bonding device - Google Patents

Abstract

PURPOSE:To provide the mechanism and method for carrying lead frames of a wire bonding device by which a lead frame can be quickly and accurately positioned to a prescribed position on a carrying path. CONSTITUTION:A stopper 11 which positions lead frames 8 being carried by carrying rollers 3 to a prescribed position is provided on a carrying passage R against the lead frame carrying mechanism equipped with guide rails 2, carrying rollers 3, and ratchets 4. In addition, the lead frame carrying mechanism is constituted in such a way that the lead frames 8 fed from a magazine 1 are first carried by the rollers 3, positioned to the prescribed position on the carrying passage R by bringing one ends of the frames 8 into contact with the stopper 11, and carried toward the magazine 1 at a prescribed pitch by means of the ratchets 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lead frame carrying mechanism and its carrying method in a wire bonding apparatus.

[0002]

2. Description of the Related Art Some wire bonding apparatuses used for semiconductor assembly are equipped with a transport mechanism for transporting lead frames. Further, some of them include a lead frame once delivered from a magazine containing the lead frames. Then, there is a so-called single magazine system in which the lead frame is stored again in the original magazine after the predetermined work is completed. If this system is adopted, the number of magazines on the supply side and the storage side can be reduced to one, so that there is an advantage that the entire apparatus can be downsized and the management of the magazines becomes very easy. On the other hand, on the other hand, since the lead frame is reciprocally transported on one transport path, it is not possible to continuously supply the lead frame. Therefore, whether or not the lead frame can be transported quickly is an important point for improving the productivity of the wire bonding device. Becomes

FIG. 8 is a schematic diagram showing a conventional lead frame carrying mechanism using a single magazine system. In the figure, 1 is a magazine for accommodating lead frames, 2 is a guide rail that forms a conveying path R of the lead frame, 3 is a conveying roller that conveys the lead frame to a predetermined position on the conveying path R, and 4 is a lead frame. Is a feed claw that conveys to the magazine 1 side at a predetermined feed pitch.

First, the lead frame (not shown) sent out from the magazine 1 is conveyed by the conveying rollers 3 in the direction of arrow A, then positioned at a predetermined position on the conveying path R, and then by the feeding claws 4. It is conveyed at a predetermined feed pitch in the direction of arrow B. At this time, the plurality of patterns formed on the lead frame and the semiconductor chips mounted on each pattern are sequentially held by the heater unit 5 and the holding frame 6 installed on the conveyance path R, and are individually held in the holding state. The semiconductor chip and the lead frame are connected by wires. When the predetermined work is completed in this way, the lead frame is stored in the original magazine 1 again by the push-back plate 7.

By the way, in the above-mentioned conventional transport mechanism,
The lead frame was positioned at a predetermined position on the transport path R by the following method. That is, first, as shown in FIG. 9, the lead frame 8 is transported by the transport roller 3 to a position where it passes the feed claw 4 on the magazine 1 side, and then one end of the lead frame 8 is brought into contact with the lead frame 8 with the feed claw 4 closed. Let Further, from that state, the lead frame 8 is fed to the side opposite to the magazine 1 by a predetermined amount by the feed claw 4,
Thereby, the lead frame 8 is positioned at a predetermined position.

In this way, when the lead frame 8 is positioned at the predetermined position on the conveying path R, the lead frame 8
The pattern 9 closest to the magazine 1 side among the plurality of patterns 9 provided on the heater unit 5 is arranged on the heater unit 5 and held by the holding frame 6. When the wire bonding to the first pattern 9 is completed, the lead frame 8 is clamped by the upper and lower feed claws 4 as shown in FIG. 10, and the predetermined feed pitch, that is, the same pitch as the arrangement of the patterns 9 of the lead frame 8 is formed. And is transported to the magazine 1 side. After that, wire bonding is sequentially performed from the pattern 9 closer to the magazine 1 by the same repeated operation. When the wire bonding of all the patterns 9 is completed, the lead frame 8 is housed in the magazine 1 again.

[0007]

However, in the above-mentioned conventional transfer mechanism, the operation procedure for positioning the lead frame 8 at the predetermined position on the transfer path R is complicated, and the positioning takes too much time. There was a problem in terms of.

The present invention has been made to solve the above problems, and is a lead frame carrying mechanism and a carrying method thereof in a wire bonding apparatus capable of quickly and accurately positioning a lead frame at a predetermined position on a carrying path. The purpose is to provide.

[0009]

The present invention has been made in order to achieve the above-mentioned object, and while carrying a long lead frame on which a plurality of semiconductor chips are mounted at a predetermined feed pitch, In a wire bonding device that connects the lead frame and the semiconductor chip with a wire,
A guide rail that forms a conveyance path for the lead frame sent out from the magazine, a conveyance roller that is provided on the conveyance path and that conveys the lead frame sent out from the magazine to a predetermined position on the conveyance path, and a lead that is conveyed to the predetermined position A lead frame transport mechanism including a feed claw that transports the frame toward the magazine side at a predetermined feed pitch, wherein a stopper for positioning the lead frame transported by the transport rollers at a predetermined position is provided on the transport path. It is a thing. Further, the stopper can be moved in the carrying direction of the lead frame. In addition, in the lead frame carrying method using the lead frame carrying mechanism in the above wire bonding apparatus, the lead frame sent out from the magazine is carried by the carrying roller, and then one end of the lead frame is brought into contact with the stopper. Then, the lead frame is positioned at a predetermined position on the conveyance path, and then the lead frame is conveyed by the feed claws toward the magazine side at a predetermined feed pitch.

[0010]

In the lead frame carrying mechanism and the carrying method according to the present invention, the lead frame sent from the magazine is carried by the carrying roller, and one end of the lead frame is brought into contact with the stopper so that a predetermined position on the carrying path is obtained. The lead frame is positioned at. Further, by making the stopper movable in the carrying direction of the lead frame, even if the dimensional specifications of the lead frame change, the predetermined position on the carrying path can be appropriately set accordingly.

[0011]

Embodiments of the present invention will now be described in detail with reference to the drawings. In the present embodiment, the same components as those in the conventional example will be designated by the same reference numerals. FIG. 1 is a schematic configuration diagram showing an embodiment of a lead frame transport mechanism according to the present invention. In the figure, reference numeral 1 is a magazine for housing the lead frames 8, and a plurality of lead frames 8 can be housed in and out of the magazine 1. Here, a plurality of patterns 9 are formed on each lead frame 8, and a semiconductor chip 10 is mounted on each pattern 9. on the other hand,
Reference numeral 2 in the drawing denotes a pair of left and right guide rails 2 that form a conveyance path R of the lead frame 8. Each guide rail 2 has a guide groove 2a having an L-shaped cross section. The lead frame 8 travels on the transport path R while being guided by the guide groove 2a.

A pair of upper and lower transport rollers 3 are provided on the transport path R with a predetermined space. These carrying rollers 3 carry the lead frame 8 sent from the magazine 1 to a predetermined position on the carrying path R.
Further, a pair of upper and lower feed claws 4 are provided on the transport path R. These feed claws 4 carry the lead frame 8 which has been carried to a predetermined position on the carrying path R toward the magazine 1 side at a predetermined feed pitch.

Here, in the transport mechanism of this embodiment,
A stopper 11 is provided on the conveyance path R of the lead frame 8. The stopper 11 is for positioning the lead frame 8 transported by the transport roller 3 at a predetermined position on the transport path R.

Further, in this embodiment, the stopper 11 provided on the conveying path R is arranged so that the conveying direction A of the lead frame 8 is
It is configured to be movable with respect to B. That is, as shown in FIG. 2, the stopper 11 is formed by projecting one end of the stopper support portion 12 upward, and the stopper support portion 12 has a ball screw 13 incorporated therein. Further, two rollers 14 (only one is shown in the figure) are attached to the lower surface side of the stopper supporting portion 12, and these rollers 14 sandwich a guide bar 15 installed in parallel with the ball screw 13 to form a stopper. 11
Also, the stopper support portion 12 is prevented from rotating.

On the other hand, both ends of the ball screw 13 have bearing members 1
It is rotatably supported by 6, and one end thereof is connected to a drive motor 18 via a coupling 17. In the above structure, when the ball screw 13 is rotated by driving the drive motor 18, the stopper support portion 12 moves while being guided by the ball screw 13 and the guide bar 15, and accordingly the stopper 11 moves in the transport directions A and B (see FIG. 1). ) Has been configured to move.

Next, a lead frame carrying method using the carrying mechanism of this embodiment will be described. First, as shown in FIG. 3, the lead frame 8 delivered from the magazine 1 is advanced to the installation position of the pair of upper and lower transport rollers 3, and the lead frames 8 are transported by the rotation of each transport roller 3. At this time, the gap between the heater unit 5 and the pressing plate 6,
The gap between the upper and lower feed claws 4 is opened to the extent that it does not interfere with the lead frame 8 traveling on the transport path R.

Then, the lead frame 8 is carried by the rotation of the carrying roller 3, and one end of the lead frame 8 is brought into contact with the stopper 11 on the carrying path R as shown in FIG. The lead frame 8 is stopped by the contact with the stopper 11 and positioned at a predetermined position on the transport path R. Further, when the lead frame 8 is positioned on the transport path R in this way, each transport roller 3 moves up and down and separates from the lead frame 8.

Further, in the thus positioned state, of the plurality of patterns 9 formed on the lead frame 8, the pattern 9 closest to the magazine 1 is arranged on the heater unit 5 and is held by the pressing plate 6. Retained (see FIG. 4). In this state, the lead frame 8 and the semiconductor chip 10 are connected by wires with a bonding tool (not shown), and the first wire bonding is completed.

When the wire bonding of the first surface is completed in this way, the gap between the heater unit 5 and the pressing plate 6 is opened again to the extent that it does not interfere with the lead frame 8 running on the transport path R. From this state, the lead frame 8 is sandwiched by the upper and lower feed claws 4 and is conveyed at a predetermined feed pitch toward the magazine 1 side by the movement of the feed claws 4. As a result, the next pattern 9 is arranged on the heater unit 5 and is held by the holding plate 6 as in the previous case (see FIG. 5). In this state, wire bonding of the second surface is performed, and thereafter, the same operation is repeated and the pattern 9 of the lead frame 8 is wire bonded in order from the side closer to the magazine 1. When wire bonding is completed for all the patterns 9 on the lead frame 8 in this way, the lead frame 8 is stored in the original magazine 1 by the push-back plate 7 as shown in FIG.

As described above, in the carrying mechanism and the carrying method of this embodiment, the lead frame 8 sent from the magazine 1 is carried by the carrying roller 3, and one end of the lead frame 8 is brought into contact with the stopper 11. With a simple operation procedure, the lead frame 8 can be quickly and accurately positioned at a predetermined position on the conveyance path R.

In the above-described lead frame carrying method, when the lead frame 8 comes into contact with the stopper 11 and there is a risk of impact or rebound, the lead frame 8 carrying speed is set to the stopper 11.
It may be better to switch to a lower speed before. By the way,
Regarding the setting of the transfer speed switching position, the rotation amount of the transfer roller 3 after the start of the transfer of the lead frame 8 is specified, or an optical sensor (not shown) that turns on and off depending on the presence or absence of the lead frame 8 is set to the switching position. It can be easily set by installing it.

In addition, in the carrying mechanism of this embodiment,
Since the stopper 11 is configured to be movable in the transport directions A and B of the lead frame 8, even if the total length of the lead frame 8 or the arrangement pitch thereof is changed, the predetermined position on the transport path R is correspondingly changed. Can be set appropriately. That is, even if the dimensional specifications of the lead frame 8 are changed due to, for example, a change in the model of the product to be handled, the stopper 11 is appropriately moved in the carrying directions A and B, and the bonding position (heater in this example is used). From the installation position of the unit 5 and the holding plate 6) to the stopper 11
By setting the distance to, as shown in FIG.
With the lead frame 8 positioned by the stopper 11, the pattern 9 closest to the magazine 1 can be accurately placed at the bonding position.

Further, an encoder or the like is attached to the rotary shaft of the drive motor 18 so that the rotation amount of the drive motor 18 can be detected, and the setting position of the stopper 11 according to the dimensional specifications of the lead frame 8 is used as the motor rotation amount in advance in a computer or the like. If it is stored in the control unit, the setup change of the device due to the specification change of the lead frame 8 can be completed in a very short time.

[0024]

As described above, according to the present invention,
Without requiring a very complicated operation procedure as in the past,
By simply bringing one end of the lead frame transported by the transport roller into contact with the stopper, the lead frame can be positioned quickly and accurately at a predetermined position on the transport path. As a result, the time required until one lead frame is sent out from the magazine and stored in the original magazine again becomes shorter than in the conventional case, so that the productivity of the wire bonding apparatus can be expected to improve. In addition, by making the stopper movable in the transport direction of the lead frame, even if the dimensional specifications of the lead frame, such as the overall length or the arrangement pitch of the patterns, changes, the predetermined position on the transport path can be set appropriately. can do.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing an embodiment of a transport mechanism according to the present invention.

FIG. 2 is a diagram illustrating a configuration of a stopper in the embodiment.

FIG. 3 is a diagram (No. 1) for explaining a lead frame transport method.

FIG. 4 is a diagram (No. 2) for explaining the method of transporting the lead frame.

FIG. 5 is a view (No. 3) for explaining the lead frame transport method.

FIG. 6 is a view (No. 4) for explaining the lead frame carrying method.

FIG. 7 is a diagram illustrating a setting state of a predetermined position by a stopper.

FIG. 8 is a schematic configuration diagram showing a conventional transport mechanism.

FIG. 9 is a diagram (No. 1) for explaining a conventional transport method.

FIG. 10 is a diagram (No. 2) for explaining a conventional transport method.

[Explanation of symbols] 1 magazine 2 guide rail 3 transport roller 4 feed claw 8 lead frame 10 semiconductor chip 11 stopper A, B transport direction R transport path

Claims (3)

[Claims] 1. A wire bonding device for connecting a lead frame and a semiconductor chip with a wire while transporting a long lead frame on which a plurality of semiconductor chips are mounted at a predetermined feed pitch. A guide rail that forms a transport path for the lead frame sent out, a transport roller that is provided on the transport path and that transports the lead frame sent out from the magazine to a predetermined position on the transport path, and a transport roller that transports the lead frame to the predetermined position. A lead frame transporting mechanism that transports the formed lead frame toward the magazine at the predetermined feed pitch, the lead frame being transported by the transport roller to the predetermined position. A wire bonder characterized in that a stopper for positioning is provided on the conveyance path. Conveying mechanism of the lead frame in ring device. 2. The lead frame carrying mechanism in a wire bonding apparatus according to claim 1, wherein the stopper is movable in a carrying direction of the lead frame. 3. A lead frame carrying method using a lead frame carrying mechanism in the wire bonding apparatus according to claim 1, wherein the lead frame sent from the magazine is carried by the carrying roller, and then the lead frame is carried by the carrying roller. One end of the lead frame is brought into contact with the stopper to position the lead frame at a predetermined position on the conveyance path, and then the lead frame is conveyed by the feed pawl toward the magazine side at the predetermined feed pitch. A method of transporting a lead frame, comprising: