JPH0314246A - Wire bonding positioning mechanism - Google Patents

Abstract

PURPOSE:To move a pin retaining member with respect to a driving member with superior controllability, and cope with lead frames of various specifications, by a method wherein the side surface of a slightly moving member is made to abut with the side surface of a driving member so as to be able to slide parallel with the moving direction of a lead frame, and moved with superior controllability by a slightly moving means. CONSTITUTION:A positioning mechanism for positioning a lead frame 3 on which a chip 2 is mounted for a wire bonder is provided with the following; a pin retaining member 6 on which a pin 5 to be inserted into a feed hole 4 of the lead frame 3 is planted, a slightly moving member 7 to which the pin retaining member 6 is fixed so as to be exchangeable, a driving member 8 driven lineally and vertically, and a slightly moving means 9 installed between the slightly moving member 7 and the driving member 8. The side surface of the slightly moving member 7 is made to abut with the side surface of the driving member 8 so as to be able to slide parallel with the moving direction of the lead frame 3, and moved with superior controllability by the slightly moving means 9. For example, as to the above slightly moving means 9, a screw 91 is fixed to the driving member 8 so as to be freely rotatable, and the pin retaining member 6 is provided with a screw hole 92 for the screw 91.

Description

[Detailed Description of the Invention] [Summary] Regarding a bonding positioning mechanism in a wire bonder, the purpose of this invention is to allow a pin holding member to move relative to a driving member with good controllability and to be compatible with lead frames of various specifications. A wire bonding positioning mechanism for positioning a mounted lead frame on a wire bonder, the mechanism comprising: a pin holding member in which a pin to be inserted into a feed hole of the lead frame is planted; and a fine movement to which the pin holding member is fixed in a replaceable manner. a drive member linearly driven up and down, and fine movement means provided between the fine movement member and the drive member, the side surface of the fine movement member being aligned with the side surface of the drive member in a lead frame. are slidably abutted in parallel to the direction of movement, and are configured to be moved with good controllability by fine movement means.

[Industrial application field]

The present invention relates to a bonding positioning mechanism in a wire bonder.

In recent years, the development of semiconductor integrated circuits (ICs) has been remarkable, and as ICs are being used in various industrial fields, the production volume of ICs is increasing dramatically.

Along with this, the importance of manufacturing technology for a series of manufacturing processes from the wafer stage to the finished product as a semiconductor device is increasing.

In the IC manufacturing process, from the wafer stage to the formation of a large number of minute elements, productivity can be improved by increasing the size of the wafer or making the circuit pattern smaller. It is planned.

The IC manufacturing process includes a die bonding (mounting) process, in which a wafer with a large number of elements formed thereon is cut into chips, and the chips are first fixed to a frame-shaped terminal called a lead frame. Another example is a wire bonding process in which the terminals of the chip and the terminals of the lead frame are connected using thin wires.

All of these steps are operations that involve mechanical operations.

Especially in the wire bonding process, IC
With the increasing density of devices, the number of terminals that require bonding is increasing, so efforts are being made to improve productivity by increasing the processing accuracy of equipment and increasing processing speed. There is.

In general, in wire bonding, in addition to improving the efficiency of the device itself called a wire bonder, it is also important to efficiently transport and support the lead frame on which the workpiece (chip) is mounted to the wire bonder at a predetermined position. However, this cannot be ignored in the bonding process.

Moreover, as ICs themselves have become more widely used, there has been an increase in the number of types of chips, and there has been an increasing trend toward order-made products with small production quantities.

Therefore, for productivity in wire bonders, it has become an important issue to be able to accurately and stably position lead frames of different specifications for different types of chips.

[Conventional technology]

In the IC manufacturing process, individual chips are scribed from a wafer and are mounted one by one on a chip mounting section called a head of a long lead frame using a device called a die bonder.

Then, it is cut into lengths corresponding to several chips mounted on the head, and these are called sheets, which are counted as 1 sheet, 2 sheets, etc.

The length of the sheet varies depending on the specifications of the lead frame and is not constant.

However, in the subsequent process, the sheet is handled in units of sheets, and for example, it is stored in a magazine and transported, or it is attached to a loading frame during resin sealing.

Incidentally, also in the wire bonder, chips are carried in a state in which they are placed on the lead frame in units of sheets.

Then, it stops when it is positioned at a predetermined position, and moves forward intermittently each time the wire bonding of each chip is completed, and when the wire bonding work has been completed for one sheet, the chip is placed on the lead frame. It will be transported out in the same condition.

FIG. 2 is an explanatory diagram of a conventional positioning mechanism.

In the figure, the lead frame feed mechanism 10 includes a feed shaft 11 that performs forward/backward, upward/downward linear motion by a drive source such as a cam (not shown), and the feed shaft 11.
A claw 13 and a protrusion 14 are fixed via an arm 12 to
, and a stopper 16 that stops the advancing feed shaft 11 when the protrusion 14 abuts against it via the buffer member 15.

The lead frame 3 on which the chip 2 is mounted is intermittently transported by inserting the claws 13 of the lead frame transport mechanism 10 into the feed holes 4 of the lead frame 3.

That is, when the feed shaft 11 descends and the pawl 13 is inserted into the feed hole 4, it moves forward and feeds the lead frame 3 forward.

Then, the feed shaft 11 stops when the protrusion 14 hits the stopper 16 via the buffer member 15, rises once, then retreats, and returns to its original position.

At this point, the lead frame 3 is lowered again and the operation of advancing the lead frame 3 is repeated.

The position of the stopper 16 can be adjusted to some extent by an adjusting screw 17.

However, the accuracy of the stop position of the lead frame 3 that has moved forward and stopped due to this lead frame feeding mechanism 10 is
For example, the positioning accuracy is roughly ±0.25 mm, and the positioning accuracy is not high enough to perform direct wire bonding.

On the other hand, the positioning mechanism 1 has a feed hole 4 in the lead frame 3.
, a pin holding member 6 on which a pin 5 that fits accurately is planted, and a driving member 8 on which this pin holding member 6 is placed and which is raised and lowered by a driving source such as a cam (not shown). It consists of

Since this positioning mechanism 1 requires precision on the order of μm, the pin holding member 6 and the driving member 8 are firmly supported by, for example, knock pins.

This positioning mechanism 1 immediately starts rising when the lead frame 3 is sent to the lead frame feeding mechanism 10, advances and roughly stops.

The processed pin 5 is fitted into the feed hole 4 of the lead frame 3 for positioning, and the positioning accuracy is as high as, for example, ±8 μm.

The accurately positioned lead frame 3 is held down from above by a sheet clamper (not shown) so that it does not move during the wire bonding operation.

In this way, the lead frame 3 on which the chip 2 is mounted is precisely positioned at a predetermined position in the wireponder by the cooperation of the lead frame feeding mechanism 10 and the positioning mechanism 1.

By the way, if the specifications of the chip 2 differ, lead frames 3 with various specifications are used accordingly.

And within this specification, a unit called a stroke,
In other words, when the length of the lead frame 3 corresponding to one element occupied by one chip changes, the interval between the feed holes 4 changes accordingly.

Naturally, then, it is necessary to change the feed pitch, which means changing the forward and backward distance of the lead frame feed mechanism 10, that is, the stroke.

Figure 3 shows examples of lead frames with different strokes; (A) is for a flat package, and (B) is for a D
T P (Dual In1ine Packag)
e) It is for.

In the figure, L and L2 are the strokes of the lead frame 3, respectively.

This stroke takes a different value depending on the size of the chip, the number and arrangement of terminals, the way it is packaged, etc.

For example, Ll is 26.42 mm and L2 is 14 mm.

Now, let's return to Figure 2.

This way, the amount to change the stroke is not that large (,
If it is within the adjustment range of the adjustment screw 17 of the stopper 16 of the lead frame feeding mechanism 10 and the stop position of the lead frame 3 does not change with respect to the feed hole 4, the stroke is corrected by adjusting the adjustment screw 17 of the stopper 16. 17.

However, when not only the stroke but also the stop position must be changed, the position of the pin 5 of the positioning mechanism 1 must be changed.

The position of the pin 5 is changed by replacing the pin holding member 6.

However, in the conventional positioning mechanism 1, since the pin holding member 6 and the driving member 8 are fixed by a knock pin, replacing the pin holding member 6 is time-consuming and troublesome.

This causes poor operation rate of the wire bonder and lowers productivity in IC manufacturing processes such as custom designs that require high-mix, low-volume production.

0 [Problems to be Solved by the Invention] As described above, the conventional positioning mechanism for a lead frame in a wire bonder consists of a pin holding member in which a pin that fits into the feed hole of the lead frame is installed, and this pin holding member. The drive member that moves it up and down was firmly fixed with a dowel pin or the like to achieve high accuracy.

Therefore, when the specification of the lead frame used differs depending on the type of chip, when trying to change the pin position, the pin holding member, which is difficult to replace, must be replaced each time.
I had to go through the trouble of replacing it.

Therefore, in the manufacturing process of ICs such as custom design, which requires high-mix, low-volume production, there is a problem in that the operating rate of the wire bonder is significantly lowered, resulting in poor productivity.

In place of the conventional mechanism in which the pin holding member in the positioning mechanism is firmly fixed to the driving member, the present invention enables the pin holding member to move relative to the driving member with good controllability.
The object of the present invention is to provide a positioning mechanism that is compatible with lead frames of various specifications.

[Means to solve the problem]

The problem described above is a wire bonding positioning mechanism that positions a lead frame on which a chip is mounted on a wire bonder, and includes a pin holding member in which a pin is inserted into a feed hole of the lead frame, and a pin holding member that is inserted into a feed hole of the lead frame. It has a fine movement member in which members are fixed to be exchangeable, a drive member that is linearly driven up and down, and a fine movement means provided between the fine movement member and the drive member, and a side surface of the fine movement member The problem is solved by a wire bonding positioning mechanism which is slidably abutted against the side surface of the member parallel to the direction of movement of the lead frame and is configured to be moved in a controlled manner by fine movement means.

[For production]

In the present invention, a pin is inserted into a feed hole provided in a frame on which a chip is mounted.
In a wire bonding positioning mechanism that stops a lead frame at a predetermined position on a wire bonder, the position of a pin can be adjusted as appropriate.

That is, a pin holding member into which a pin is implanted, and a driving member that linearly drives the pin holding member up and down,
In the past, for example, they were directly fixed by a knock pin, but in the present invention, a fine movement member is interposed between the two.

The fine movement member is configured to hold a pin holding member in a replaceable manner.

At the same time, a fine movement means is provided in the supporting portion of the fine movement member and the drive member, so that the fine movement member moves slightly with respect to the drive member in a direction parallel to the moving direction of the lead frame while the walls of both slide. I have to.

In this fine movement means, for example, an adjustment screw is rotatably fixed to the drive member, and a screw hole that engages with the screw is provided in the pin holding member, and by turning the screw, the fine movement member is moved back and forth with respect to the drive member by μm. It is possible to make slight movements in units of .

In this way, when the wire bonder handles a lead frame with a different specification for the feed hole due to a change in the type of chip, it is no longer necessary to take the time and effort to replace the pin holding member as in the conventional case.

Therefore, it is possible to improve the operating rate of the wire bonder.

Furthermore, since the position of the pin can be finely adjusted using the adjustment screw, bonding positioning is stable and the quality of wire bonding can be improved.

〔Example〕

FIG. 1 is a detailed explanatory diagram of the present invention.

In the figure, a pin 5, a pin holding member 6, a fine movement member 7,
The drive member 8 and the like were all manufactured using stainless steel.

Among these, the pin 5 is a key part that fits into the feed hole 4 of the lead frame 3 and performs bonding positioning with high precision.The tip portion inserted into the feed hole 4 has a diameter of 2 mm. It was finished with a tolerance of ±0.002 mm.

Further, the hole provided in the pin holding member 6 was finished with a tolerance of H7 with respect to the nominal size of 4 mm.

On the other hand, the root part of pin 5 that fits into this hole is H6.
I doubled it and made a stop fit.

Further, the pin holding member 6 and the fine movement member 7 were aligned using taper pins and then removably fixed using screws (not shown).

The drive member 8 is linearly driven vertically with high precision by a cam (not shown).

The fine movement member 7 is arranged so as to be placed on the drive member 8.1. The mirror-finished walls are designed to slide against each other.

The fine movement means 9 is provided with a set screw 71 passing through a long hole provided in the side wall of the fine movement member 7, so that it can be firmly fixed to the drive member 8.

Next, the fine movement means 9 has a diameter of 6 mmφ and a pitch of 0.
A screw 91 with a very fine opening of 5 mm was used, and the screw 91 was rotatably supported on both sides of a hole provided in the protrusion 81 of the drive member 8 by an E IJ song.

The tip of this screw 91 was adapted to mesh with a screw hole 92 provided in the fine movement member 7.

Further, the head of the screw 91 is knurled so that it can be turned by hand.

The performance of the positioning mechanism 1 thus assembled was evaluated by operating it in combination with the lead frame feeding mechanism 10.

As a result, when the lead frame 3 is transported by the lead frame feeding mechanism 10, even if the stopper 16 is adjusted, the stopping position accuracy is at most ±0.25 mm, but the positioning mechanism 1 can finely adjust the stopping position. Then, ±8m
It was confirmed that the lead frame 3 could be positioned with an accuracy of m.

In this case, a screw and a tapped hole are used as the fine movement means, but various modifications are possible, such as a combination of a screw and a spring, or a lever or a cam.

In addition, the shape of the sliding wall may be circular instead of rectangular. For example, various modifications can be made, such as using a round shaft for the driving member and providing a loose fit by providing a round hole in the micro-moving member. It is possible.

〔Effect of the invention〕

As described above, in the conventional positioning mechanism for a lead frame in a wire bonder, the pin holding member is directly connected to the driving member, and therefore the pin cannot be adjusted and moved.

Therefore, when the specifications of the lead frame change, it is time consuming to replace the pin holding member, which significantly reduces the operating rate of the device.

On the other hand, in the positioning mechanism according to the present invention,
A fine movement member is arranged between the pin holding member and the driving member,
The pin holding member and the pin implanted therein can be finely moved by the fine movement means in micrometer units.

Therefore, after rough positioning is performed by the lead frame feeding mechanism, fine adjustment is performed by the positioning mechanism according to the present invention, and the lead frame is positioned at a predetermined position of the wire honda.

In this way, since the operating rate of the apparatus in the wire bonding process is improved and the bonding position accuracy is high, a great effect on improving the quality of wire bonding can be expected.

[Brief explanation of drawings]

FIG. 1 is a detailed explanatory diagram of the present invention, FIG. 2 is an explanatory diagram of a conventional positioning mechanism, and FIG. 3 is an example of lead frames with different strokes. In the figure, (2) is a positioning mechanism, 3 is a lead frame, 5 is a pin, 7 is a fine movement member, and 9 is a fine movement means. is the chip, is the feed hole, is the pin holding member, is the drive member,

Claims (1)

[Claims] A wire bonding positioning mechanism for positioning a lead frame (3) on which a chip (2) is mounted on a wire bonder, comprising: a pin ( 5), and a fine movement member (7) to which the pin holding member (6) is fixed in a replaceable manner.
), a driving member (8) that is linearly driven up and down, and a fine movement means (9) provided between the fine movement member (7) and the drive member (8), and the fine movement member ( 7) is slidably abutted against the side surface of the drive member (8) in parallel to the moving direction of the lead frame (3), and is controlled by the fine movement means (9) with good controllability. A wire bonding positioning mechanism characterized by being moved.