JPH0473293B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to semiconductor manufacturing equipment, and more particularly to a lead frame transport device for transporting and positioning lead frames during semiconductor chip mounting.

[Technical background of the invention and its problems]

Generally, when mounting semiconductor chips, die bonding or wire bonding is performed at a specific location using a lead frame transport device that transports and positions a lead frame, on which leads corresponding to multiple chips are continuously formed, at a predetermined pitch. etc.

As shown in FIG. 1, the conventional lead frame transport device includes guide rails 2 that support the widthwise ends of the lead frame 1 and form guide paths for transporting the lead frame 1 in the longitudinal direction. and 3 are arranged in parallel, and in order to transfer the lead frame 1 to a position A where die bonding or wire bonding is performed (hereinafter simply referred to as the bonding position), feed claws 4 to 7 are placed on a shaft 8 parallel to the guide rail. A feeding mechanism is provided in which these are arranged and driven by a cam or crank (not shown), and a positioning pin is provided near the bonding position A in a direction perpendicular to the flat surface of the lead frame 1. A positioning device (not shown) that reciprocates is provided.

In this case, grooves and holes of various shapes are formed in the lead frame 1, and when transporting it,
For example, a square hole 1a formed at one end in the width direction
However, for positioning, a round hole 1b formed at the other end in the width direction is used.

Therefore, pieces 4a to 7a that engage with the square holes 1a are attached to the tips of the feed claws 4 to 7, respectively.
A positioning pin 9 that fits into the round hole 1b is attached to the positioning device.

In such a conventional lead frame conveying device, the bonding position A is usually fixed and the parts to be bonded of the lead frame 1 are sequentially stopped at this position. The guide rails 2 and 3 had to be distributed from the center and adjusted individually, and the positions, relative spacing and strokes of the feed pawls 4 to 7 had to be adjusted for lead frames of different pitches. Furthermore, for lead frames with different hole shapes, the pieces 4a to 7a and the positioning pins 9 must be adjusted or changed.

Normally, different types of lead frames have different widths and
Pitch, hole shape, etc. often change at the same time because they are related to each other, and it takes a lot of time to make adjustments and replace parts each time. Since completeness may be detected, there are drawbacks such as a significant decrease in product yield.

[Purpose of the invention]

The present invention has been made in order to eliminate the drawbacks of the above-mentioned conventional ones, and enables highly accurate and quick adjustment for lead frames of different shapes, and can improve operating rates and product yields. The purpose is to provide a lead frame conveying device.

[Summary of the invention]

In order to achieve this object, the present invention provides a lead frame transport device that transports a lead frame along a guide rail and transports and positions the lead frame at a pitch determined depending on the type of lead frame. provisional positioning means for temporarily positioning the lead frame in front of the bonding position; and intermittent feeding means capable of feeding the temporarily positioned lead frame to the bonding position by adjusting the stroke. Both are characterized in that the stroke is adjusted to two types: a carry-in pitch feed amount determined by the temporarily determined position and a feed pitch amount specific to the lead frame.

[Embodiments of the invention]

Hereinafter, one embodiment of the present invention will be described with reference to the accompanying drawings.

FIG. 2 is a plan view of a lead frame conveying device according to the present invention, and FIG. 3 is a side view thereof, in which the same reference numerals as in FIG. 1 indicate the same elements.

This lead frame transport device mainly includes a pedestal section 10 that fixes guide rails 2 and 3 and each drive system described below, and a carry-in device 20 that feeds lead frames before bonding along the guide rails 2 and 3. A carry-out device 30 that sends out the lead frame after bonding processing to the next processing step, and an intermittent feed whose stroke can be arbitrarily adjusted and which sequentially transfers the lead frames fed by the carry-in device 20 with the adjusted stroke. It consists of a device 40, a temporary positioning device 50 for temporarily positioning the lead frame by abutting the leading end thereof when the lead frame is carried in, and a turret type positioning device 60 for positioning during bonding.

Here, the pedestal section 10 has an intermediate substrate 13 connected to a main substrate 11 by a support plate 12, and furthermore, a pair of support plates 1 are disposed on the intermediate substrate 13.
4 and 15 are spaced apart from each other, and these support plates 14 and 15
Guide rails 2 and 3 are fixed on top. Note that grooves 14a and 15a are provided in the parts of the support plates 14 and 15 to which the guide rail 3 is attached, respectively, so that the guide rail 3 can be moved relative to the width direction of the lead frame 1 with the guide rail 2 as a reference. It's getting old.

Next, the carrying-in device 20 has a pair of roll support parts 21
a driving roll mechanism having rollers 22 at each shaft end thereof and coupled to an electric motor 23 via a belt;
At both ends of the U-shaped roll support section 24,
A roller 25 is attached to press the side end of the lead frame 1 together with the roller 22, respectively, and
Additionally, it is comprised of a driven roll mechanism having a cylinder 26 for opening and closing the roll gap.

Similarly, the unloading device 30 also has rollers 32 at the shaft ends of a pair of roll supports 31, a driving roll mechanism connected to an electric motor 33 via a belt, and a U-shaped roll. Rollers 35 are provided at both ends of the support section 34 to press the side ends of the lead frame 1 together with the rollers 32, respectively.
and a driven roll mechanism having a cylinder 36 for opening and closing the roll gap.

Next, the intermittent feeding device 40 has a pair of chuck mechanisms 44 that clamp the side ends of the lead frame 1 from both sides by a fixed claw 41 and a movable claw 42 whose relative spacing can be changed by a cylinder 43. , slide shafts 4 arranged parallel to the guide rails 2, respectively.
5 are installed spaced apart in two sets in the axial direction, and further,
This slide shaft 45 is connected via an arm 46 to a nut 47 that is screwed onto a screw shaft 48, and by rotating the screw shaft 48 with an electric motor 49, the chuck mechanism 44 is moved in the direction along the guide rail 2. It is configured to perform a stroke motion.

Next, the temporary positioning device 50 is disposed on the guide rail 2 side and in the middle part in the longitudinal direction, and has a stopper 51 with which the leading end of the lead frame 1 is brought into contact when the lead frame 1 is carried in, and a stopper 51 that is disposed on the guide rail 2 side and at the middle part in the longitudinal direction. Cylinder 52 that releases the stopper 51
It is equipped with.

Further, the positioning device 60 is provided at the bonding position, and has a plurality of positioning pins 61 arranged in a turret shape. The tip is inserted into a hole in the lead frame 1. Other components include a heater block 62, a frame holder (not shown), and the like.

On the other hand, a shaft 18 parallel to the guide rails 2 and 3 is rotatably supported through the support portion 12 between the substrate 11 and the intermediate substrate 13 of the pedestal portion 10, and the lead frame of this shaft A sensor group 16 is attached to the carry-in end, a cam group 17 is attached to the axially intermediate portion corresponding to the positioning device 60, and an electric motor 19 is provided to the lead frame carry-out side end of this shaft. In addition, cam group 1
7 is a positioning device 6 via a connecting member (not shown).
0 is activated.

Further, near the temporary positioning device 50, there is a sensor 71 that detects the leading end of the lead frame 1 that has been carried in, and a sensor that detects that the rear end of the lead frame 1 that is being transported at a predetermined pitch has passed. 72 are arranged in parallel in the direction in which the lead frame 1 is transported.

Note that all drive systems including electric motors or cylinders such as the intermittent feeding device 40, temporary positioning device 50, and positioning device 60 described above are connected to the guide rail 2.
concentrated on the side.

The operation of the lead frame conveying device configured as described above will be explained below.

First, since the drive system including the electric motor or cylinder is fixed integrally with the guide rail 2, if the width of the lead frame 1 changes, the guide rail 3, whose mounting position can be changed at any time, must be adjusted. to form a guide path commensurate with the width of the lead frame. When the lead frame 1 is fed after completing this adjustment, it is bitten by the rollers 22 and 24 constituting the carry-in device 20 and moves toward the bonding position A, and its tip abuts against the stopper 51. At this time, the sensor 71 detects the lead frame 1 and the rollers 22 and 2
4, the cylinder 26 is operated to widen the gap. Therefore, the lead frame 1 is connected to the stopper 5.
It stops when it comes into contact with 1.

In this state, when the electric motor 19 is driven, the positioning device 60 is released by the cam group 17, and then the cylinder 43 that constitutes the intermittent feed device 40 is actuated by the sensor group 16, and the fixed claw 41 and the movable claw 42 are operated. While holding the lead frame 1 with
When the electric motor 49 of the intermittent feeding device is driven with the cylinder 52 constituting the temporary positioning device 50 activated and the stopper 51 released, the lead frame 1 is transferred with a predetermined stroke. Of course, when this transfer is completed, the cylinder 43 is returned and the lead frame 1 is released, but the cam group 17 driven approximately in synchronization with this actuates the positioning device 60 to move the positioning pin 61 to the lead frame. Insert it into hole 1.

In this way, the transfer and positioning of the lead frame are completed, and the bonding operation at the bonding position A is performed. Further, during the bonding operation, the intermittent feeding device 40 returns to the illustrated state.

Next, after performing the bonding operation, when the electric motor 19 is driven again, the positioning pin 61 is lowered and the intermittent feeding device is synchronized, so that the transfer operation, positioning operation, and bonding operation of the lead frame 1 are sequentially repeated.

Subsequently, the lead frame 1 is detected by the sensor 72.
When the passage of the tail end of the lead frame 1 is detected and a series of bonding operations are completed, this lead frame 1 is sent to the next process by the carry-out device 30, while a new lead frame 1 is transferred to the carry-in device 30.
sent by.

FIG. 4 shows the relationship between the position of the stopper 51, the bonding position A, and the stroke of the intermittent feeder 40. The pitch feed amount specific to the lead frame is P ₁ from the tip to the point where it is first bonded. The dimensions of P ₂ , that is, the loading pitch feed amount determined by the temporary position of the lead frame (hereinafter referred to as end surface dimensions), and the stopper 5
If the distance between the lead frame 1 and the bonding position A is L (constant), the lead frame in contact with the stopper 1 needs to be moved by L+P ₂ .

On the other hand, the control device (not shown) of the intermittent feeder 40 is equipped with a numerical input section for inputting these values P ₁ , P ₂ and L, and these values can be input when the type of lead frame is changed. Then, every time a new lead frame 1 arrives, the intermittent feeding device 40 repeats the transfer operation with a stroke of (L+P ₂ )/2 twice, then repeats the transfer operation with a stroke of P ₁ , and frame 1
The structure is such that fast forwarding is performed when moving forward while holding the button.

In this way, even when bonding different types of lead frames, all you need to do is change the mounting position of the guide rail 3 according to the width of the lead frame, and input numerical values for pitch P ₁ and end face dimension P ₂ .
This significantly shortens the adjustment time, and allows for accurate transfer and positioning operations depending on the type of lead frame.

In particular, this lead frame conveying device first temporarily positions the lead frame using the stopper 51, and then moves the aligned lead frame to
Since the stroke is sequentially transferred by the variable intermittent feed device, there is no need for mechanical adjustment of the heart, which required the most delicate adjustment in conventional devices.

In the above embodiment, a turret type positioning device 60 is used to insert the positioning pins 61 into matching holes in order to avoid cumulative errors when the lead frame is intermittently fed. If the number of frames is small, this positioning device 60 may be removed, or alternatively, an optical position detection device or the like may be used in place of this positioning device 60 to control the feed amount so that the frame is Even when a large number of holes or grooves are formed in succession, it is possible to construct a conveying device that does not require any holes or grooves.

Further, in the above embodiment, the lead frame in contact with the stopper 51 is fed in two steps until it can be bonded for the first time, but an intermittent feeding device with a wide stroke adjustment range is used. In this case, only one feeding operation is required, thereby further improving work efficiency. Furthermore, it is of course possible to move the guide rail 3 by an external command.

〔Effect of the invention〕

As is clear from the above description, according to the lead frame conveying device of the present invention, it is possible to transfer and position different types of lead frames without using any holes or grooves formed in the lead frames. This makes it possible to eliminate the delicate adjustments and parts replacement work required for conventional equipment, and enables rapid and highly accurate adjustment, resulting in excellent effects such as greatly improving productivity and product yield.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing the structure of a conventional lead frame transfer device, FIG. 2 is a plan view showing the structure of an embodiment of the lead frame transfer device according to the present invention, and FIG. 3 is a plan view showing the structure of the same embodiment. The side view shown in FIG. 4 is a plan view showing the positional relationship of the main parts in order to explain the operation of the same embodiment. 1... Lead frame, 2, 3... Guide rail,
4-7... Feed claw, 10... Frame section, 20... Carrying-in device, 30... Carrying-out device, 40... Intermittent feeding device, 41
...Fixed claw, 42... Movable claw, 50... Temporary positioning device, 51... Stopper, 60... Positioning device.

Claims (1)

[Scope of Claims] 1. In a lead frame conveying device that carries in a lead frame along a guide rail, and moves and positions the lead frame at a pitch determined by the type of the lead frame, the lead frame is moved to a bonding position. comprising temporary positioning means for temporarily positioning the lead frame in the previous stage, and intermittent feeding means capable of adjusting the stroke and sending the temporarily positioned lead frame to the bonding position,
A lead frame conveying device characterized in that the intermittent feeding means adjusts to two types of strokes: a carry-in pitch feed amount determined by at least a temporarily determined position and a feed pitch amount specific to the lead frame. 2. The intermittent feeding means includes a chuck mechanism that clamps the side end portion of the lead frame by a pair of claws, at least one of which is movable, a screw shaft that moves the chuck mechanism along the guide rail, and a screw shaft that moves the chuck mechanism along the guide rail. The lead frame conveying device according to claim 1, comprising: a motor for rotating; and a control device for inputting a numerical value corresponding to the stroke and controlling the motor in accordance with the numerical value. .