JP2584331Y2 - Driven roller structure of wire feeder - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a driven roller structure of a wire feeder for supplying a wire made of a solder material during die bonding.

[0002]

2. Description of the Related Art Conventionally, in the process of manufacturing a semiconductor device, die bonding is performed in which a semiconductor chip called a die is joined to a base material such as a lead frame or a stem via a solder material. On the other hand, in supplying the solder material to a bonding portion such as a base material at the time of such die bonding, there are a case where the solder material is supplied in a foil shape and a case where a necessary amount of a wire-like solder material is supplied. In the latter case, only the required amount of wire is supplied during die bonding.
For example, the following wire supply device is used.

[0003] That is, a wire made of a solder material whose one end is wound on a reel is sandwiched between a pair of metal rollers consisting of a driving roller and a driven roller, and then inserted into an insertion hole of a guide. In accordance with the bonding operation, the driving roller is driven to rotate to send the wire to the guide side, and the wire is sent out from the tip of the guide. The driven roller is for pressing the wire against the driving roller, and rotates following the wire sent to the insertion hole of the guide. Also, the amount of wire sent from the tip of the guide,
That is, the amount of the solder material supplied to the bonding portion is controlled by controlling the rotation amount of the driving roller.

[0004]

However, in such a conventional wire supply device, when the wire is bent at a portion inserted into the insertion hole of the guide, the insertion resistance of the wire in the insertion hole is reduced. If it is large, the rotating driving roller may run idle and the wire may not be fed, or sometimes the driving roller may run idle and the amount of wire fed from the tip of the guide may become insufficient. Was. As a result, in the former case, there is a problem that the bonding operation is interrupted, and in the latter case, a bonding failure occurs.

Of course, such a problem can be solved by increasing the diameter of the insertion hole provided in the guide. However, when the diameter is increased, the positional accuracy of the wire supplied from the tip of the guide decreases, and accordingly, the semiconductor chip and the A new problem occurs in that the bonding accuracy with the base material is reduced. Also, in order to prevent idling of the driving roller without impairing the bonding accuracy, the load of the driven roller pressing the wire against the driving roller may be increased.
Since both rollers are made of metal, there is a problem that the wire is crushed and cannot be inserted into the insertion hole.

The present invention has been made in view of such circumstances, and has as its object to provide a driven roller structure of a wire supply device capable of reliably sending out a wire made of a solder material from a guide.

[0007]

According to the present invention, in order to solve the above-mentioned problems, at the time of die bonding for joining a semiconductor chip to a base material, a solder material inserted into a guide and extending from the tip thereof is used. A wire feeding device for feeding a wire to a bonding location, wherein the wire is pressed against a driving roller by a driven roller, and the driving roller is rotated to feed the wire into the guide, and In a configuration in which the amount of extension of the wire at the tip of the guide is controlled based on the amount of rotation of the roller, the driven roller is formed of an elastic body.

[0008]

In the above construction, since the driven roller is formed of an elastic body, when the wire is pressed against the driving roller, the driven roller is elastically deformed at the contact portion with the wire, and is applied to the driving roller so as to surround the wire. Touch Therefore, when the driving roller is driven to rotate, the driven roller is always rotated by the driving roller. Therefore,
Even if the insertion resistance of the wire inside the guide is large, the driving roller does not run idle and the wire is fed into the guide by both rotating rollers.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 and FIG. 2 are views showing a main part of a wire feeding device 1 using the driven roller structure of the present invention. The wire supply device 1 is for supplying a required amount of solder material to a bonding portion between a semiconductor chip and a substrate during die bonding. The wire supply device 1 has a support wall 2. An arm 3 extending upward is formed at the upper end of the support wall 2, and a reel 4 is provided at the tip of the arm 3.
Are rotatably supported. A wire 5 made of a solder alloy is wound around the reel 4.

On the other hand, a guide 6 is provided at the lower end of the support wall 2 below one end of the reel 4 in the horizontal direction. The guide 6 is provided on a guide body 7 supported by the support wall 2 and a lower end of the guide body 7.
It has a supply port 8 having a tapered tip, and a pipe 9 fitted inside the guide body 7, the lower end of which is located at the tip of the supply port 8, and the upper end of which protrudes above the guide body 7. ing. One end of the wire 5 drawn from the reel 4 is inserted into the pipe 9 and reaches the tip of the supply port 8.

A pair of driving rollers 1, which sandwich the wire 5, are located above the guide 6 on the support wall 2.
0 and a driven roller 11 are provided. Drive roller 10
Is rotatably attached to the support wall 2. Further, the driving roller 10 has a roller portion 12 in contact with the support wall 2 and a pulley 13 integrally formed on a side surface of the roller portion 12, and the peripheral surface of the roller portion 12 has a V-shaped cross section. Groove 1
2a is engraved. Further, the driving roller 10 is connected to a step motor (not shown) via a belt 14 stretched over a pulley 13 so that the driving roller 10 is sequentially driven to rotate by a predetermined rotation amount in accordance with the bonding operation. .

Above the driving roller 10, one end of an arc-shaped lever 15 is rotatably supported by the support wall 2 via a shaft 16. On the side surface of the lever 15, three pins 17 are provided at regular intervals in accordance with the curvature of the lever 15, and one of them is provided with a support pin 18 provided on the support wall 2 side. The other end of the lever 15 is urged toward the driving roller 10 by a spring 19 stretched between them. The biasing force can be changed by selectively replacing one end of the spring 19 with the pins 17.

On the other hand, the driven roller 11 is rotatably attached to the other end of the lever 15. The driven roller 11 is made of rubber, and a fixed shaft of a bearing 20 provided at the center of the shaft is fixed to the lever 15 via a nut 21. The driven roller 11 is connected to the lever 15
Is pressed toward the driving roller 10 by the spring force of the spring 19, thereby pressing the wire 5 against the groove 12a of the roller portion 12 of the driving roller 10. In this state, the driven roller 11
Since it is made of rubber, as shown in FIGS. 3 and 4, its peripheral surface is elastically deformed by a contact point with the wire 5,
As a result, the driven roller 11 is in contact with the roller portion 12 of the driving roller 10 so as to surround the wire 5.

The supporting wall 2 is provided with a leaf spring 22 at a position where the lever 15 is mounted, and the wire 5 hanging from the reel 4 is moved by the leaf spring 22 by the driving roller 1.
It is guided so as to be located between 0 and the driven roller 11.

In the above configuration, when the driving roller 10 is rotated by a stepping motor (not shown) in accordance with the bonding operation at the time of die bonding, the wire 5 pressed by the driven roller 11 is reduced in its rotation amount. In response, it is sent into the pipe 9 of the guide 6.
Along with this, the tip of the wire 5 is sent out from the tip side of the supply port 8 of the guide 6. At this time, the step motor is controlled so as to rotate and stop by a predetermined number of steps from the time point when it is detected that the wire 5 has come into contact with the bonding portion. As a result, the feed amount of the wire 5 is controlled, and a necessary amount of the wire 5, that is, a solder material is always supplied to the bonding portion between the semiconductor chip and the base material.

On the other hand, at the time of such an operation, the driven roller 11 is in contact with the roller portion 12 of the driving roller 10 as described above, so that when the driving roller 10 is driven to rotate, the driving roller 10 The driven roller 11 is constantly rotated. Thus, the wire 5 is fed into the pipe 9 of the guide 6 by both rotating rollers 10, 11. For this reason, when the wire 6 is bent at the portion inserted into the pipe 9, the wire 5 in the pipe 9 may be bent.
Even when the insertion resistance is large, the wire 5 is reliably fed into the pipe 9 without idling of the driving roller 10.

Therefore, the diameter of the pipe 9 can be increased,
The wire 5 can be reliably sent out from the tip of the guide 6 without increasing the load of the driven roller 11. As a result, interruption of the bonding operation and occurrence of bonding failure can be prevented beforehand while maintaining the bonding accuracy.

Further, the driven roller 11 is capable of driving the driving roller 1 even when the outer dimensions of the wire 5 are slightly increased.
0 is kept in contact with the roller unit 12. Therefore, it is possible to cope with a change in the outer dimensions of the wire 5.

[0019]

As described above, in the driven roller structure of the wire supply device according to the present invention, in the wire supply device in which the wire made of the solder material sent to the guide side is pressed against the driving roller by the driven roller, Is formed by an elastic body, when the wire is pressed against the driving roller, the driven roller is elastically deformed at the contact portion with the wire and contacts the driving roller. And
When the driving roller is driven to rotate, the driven roller always rotates the driven roller. Therefore, even when the insertion resistance of the wire inside the guide is large, the wire is sent to the inside of the guide by both rotating rollers without the driving roller idling.

Accordingly, the wire can be reliably sent out from the tip of the guide without increasing the diameter of the insertion hole or the like provided in the guide for inserting the wire or increasing the load on the driven roller. As a result, interruption of the bonding operation and occurrence of bonding failure can be prevented beforehand while maintaining the bonding accuracy.

Further, the driven roller maintains the state of contact with the roller portion of the driving roller even when the external dimensions of the wire are slightly increased. Therefore, it is possible to cope with a change in the external dimensions of the wire.

[Brief description of the drawings]

FIG. 1 is a front view of a main part of a wire supply device showing an embodiment of the present invention.

FIG. 2 is a right side view of FIG. 1 showing the same embodiment.

FIG. 3 is a schematic explanatory view corresponding to FIG. 1 showing a driving roller, a driven roller, and a wire of the embodiment.

FIG. 4 is a view taken in the direction of arrow A in FIG. 3;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Wire supply apparatus 5 Wire 6 Guide 10 Driving roller 11 Driving roller

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H01L 21/52 H05K 3/34 505

Claims (1)

(57) [Scope of request for utility model registration] 1. A wire supply device for supplying a wire made of a solder material inserted into a guide and extending from a tip thereof to a bonding portion during die bonding for bonding a semiconductor chip to a base material. While the driven roller is pressed against the driving roller, the driving roller is rotationally driven to feed the wire into the guide, and the amount of extension of the wire at the tip of the guide is controlled based on the rotation amount of the driving roller. In the above configuration, the driven roller is formed of an elastic body.