JP3167173B2 - Method and apparatus for transporting band-shaped member - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for transporting a strip-shaped member.
The present invention relates to a method and an apparatus for transporting a lead frame attached to a die bonder for mounting a semiconductor pellet on a strip-shaped lead frame.

[0002]

2. Description of the Related Art For example, a semiconductor device is manufactured collectively by using a strip-shaped metal lead frame.
As the manufacturing process, a pellet mounting process of mounting a semiconductor pellet on the lead frame, a wire bonding process of electrically connecting the semiconductor pellet and the lead with a thin metal wire, and covering a main portion including the semiconductor pellet with an exterior resin. Resin molding process.

[0003] In the above-mentioned pellet mounting step, a manufacturing facility called a die bonder for mounting a semiconductor pellet after supplying a silver paste onto a lead frame is used, and the die frame is provided with the lead frame intermittently at a constant pitch. A transfer device for transferring the data to the storage device is provided.

[0004] Conventionally, this lead frame transport device has
As shown in FIG. 9, a transport rail (2) for guiding the lead frame (1) in the transport direction, and upper and lower grippers (3) (4) disposed above and below the lead frame (1) on the transport rail (2). ) Constitutes the main part. The upper and lower grippers (3) and (4) are provided so as to be horizontally movable along the lead frame transfer direction.
The upper gripper (3) is provided so as to be vertically movable along the vertical direction, while the lower gripper (4) is provided in a fixed state in the vertical direction.

In the above transport device, the lead frame (1)
By moving the movable upper gripper (3) close to the fixed lower gripper (4), the gripper is pinched and gripped. In this state, the upper and lower grippers (3) and (4) are advanced to move the transfer rail (2). Transfer while guiding. At this time, the lead frame (1) is slightly lifted from the transport rail (2) so that transfer by the upper and lower grippers (3) and (4) can be performed smoothly. Then, after the lead frame (1) is transferred at a constant pitch, the upper gripper (3) is lifted and opened, and then the upper and lower grippers (3) and (4) are retracted to return to the initial position, and the next transfer operation is performed. Wait for it. By repeating this series of operations, the lead frame (1) is intermittently transported at a constant pitch. Although not shown, the silver paste is supplied onto the lead frame (1) at the fixed position during the transfer, and then the semiconductor pellet is mounted on the lead frame (1) at the next fixed position.

[0006]

In the above-described conventional transfer apparatus, the upper gripper (3) is movable in the vertical direction and the lower gripper (4) is fixed in the vertical gripper (3) (4). Therefore, there were the following problems.

That is, in order to smoothly transfer the lead frame (1) guided by the transfer rail (2), the grip position by the upper and lower grippers (3) and (4) is set slightly higher than the transfer rail (2). Must therefore be
The upper end of the fixed lower gripper (4) is positioned higher than the transport rail surface. As a result, the upper and lower grippers (3) (4)
When the rail moves backward and returns to the initial position, the transport rail (2)
The lower gripper (4) retreats while rubbing the lower surface of the lead frame (1) floating above the lead frame (1).

When the lower gripper (4) retreats while rubbing against the lead frame (1) in this manner, the lead frame (1) is deformed, or the lead follows the retraction of the lower gripper (4) due to friction between the two. There was a problem that the frame (1) also receded. In the silver paste supply position and the pellet mount position in the middle of the transfer of the lead frame (1), the lead frame (1) is positioned by pressing with the clamper. In the state of floating from 2), there is a problem that the pressing by the clamper cannot be performed reliably and the lead frame (1) cannot be positioned with high accuracy.

The present invention has been proposed in view of the above problems, and an object of the present invention is to provide a method and apparatus for transporting a strip-shaped member capable of smoothly and reliably transporting a lead frame. To provide.

[0010]

As a technical means for achieving the above-mentioned object, the present invention relates to a method for opening and closing a strip-shaped member guided by a conveying rail by a single drive source.
And sandwiching with upper and lower grayed <br/> gripper that can move in the vertical direction by the operation timing, and transported along the transport rail, then, in the reverse closing operation timing causes return the gripper to its initial position, the Opening / closing operation timing
When the upper and lower grippers open, the upper gripper
So that the lower gripper starts lowering.
Characterized in that was.

In the apparatus of the present invention, the strip-shaped member guided by the transport rail is sandwiched by upper and lower grippers movable in the vertical direction. Open and close by moving, open and close
Move the operation timing to the upper gripper when the upper and lower grippers open.
The lower gripper starts lowering after the
And a link mechanism for moving the cam along the transfer direction of the band-shaped member, and a single drive source for operating the link mechanism. And

[0012]

According to the present invention, both the upper and lower grippers are movable in the vertical direction, and when the upper and lower grippers are released from the band-shaped member, the upper and lower grippers are completely separated from the band-shaped member to maintain a non-contact state. I do. In addition, the upper and lower grippers are opened and closed by a single drive source via a link mechanism by moving the cam strip along the transfer direction, thereby ensuring that the upper and lower grippers are opened and closed completely synchronously. In addition,
The opening / closing operation timing of the ripper is controlled by the opening / closing operation of the upper and lower grippers.
Sometimes the upper gripper rises first, then the lower gripper
Is set to start descending.
The desired stress is prevented from being applied.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS. In the following embodiments, a case will be described in which the present invention is applied to a lead frame transfer device attached to a die bonder used in a pellet mounting step in the manufacture of a semiconductor device.

In FIGS. 1 and 2, reference numeral (11) denotes a transport rail for guiding a lead frame (12), which is a strip-shaped member, and is integrally attached to a fixed base (13). (1
4) is a cylinder serving as a drive source for opening and closing the upper and lower grippers provided on the fixed base (13), and (15) is a transfer rail (1).
With the link mechanism located on the side of 1), the transport rail (1
A long link lever (16) arranged in parallel with the direction in which 1) extends is supported on a fixed base (13) by a link arm (17) rotatably supported about a fulcrum (a) [FIG. 2 middle places]. One end of the link lever (16) is connected to a cylinder head (18) of the cylinder (14) via a bearing (19) so as to be vertically movable.

Reference numeral (20) denotes upper and lower gripper units (three places in the drawing) arranged at regular intervals near the side of the transfer rail (11) along the direction in which the transfer rail (11) extends. Has the following configuration.

That is, as shown in FIGS. 1 to 5, a substantially L-shaped arm (23) is supported on a unit base (22) via a slide base (21) described later provided on a fixed base (13). The roller (24), which is rotatably supported on the (b) center and is attached to one end of the L-shape, is connected to the long hole (25) formed in the link lever (16). A cam block which is fitted in the [three places in the figure] and is mounted on the unit base (22) so that the roller (26) attached to the other end is movable in the horizontal direction via the linear way (27). Fit into the long hole (29) formed in (28). A cam (31) having a cam surface (30) for opening and closing the upper and lower grippers at a predetermined timing to be described later is integrally attached to a tip portion of the cam block (28). On the other hand, the upper and lower gripper blocks (32) and (33) are independently mounted on the unit base (22) via the linear ways (34) and (35) so as to be vertically movable,
Upper and lower grippers (36, 37) for holding the lead frame (12) from above and below are integrally attached to the lower ends of the upper and lower gripper blocks (32, 33). Also, cam followers (38) and (39) that follow the cam (31) are supported at the upper ends of the upper and lower gripper blocks (32) and (33), respectively, so that the upper and lower gripper blocks (32) and (33) and the unit base (2
The cam followers (38) and (39) abut against the cam surface (30) of the cam (31) due to the elastic force of the springs (40) and (41) stretched between the cam followers (2) and (2).

Next, a feed mechanism for moving the upper and lower gripper units (20) by a constant pitch along the transport rail (11) will be described.

As shown in FIG. 6, each of the upper and lower gripper units (20) (three in the figure) is commonly mounted on a long slide base (21) along the direction in which the transport rail (11) extends. The slide base (21) is fixed base (1
3) Transfer rail (1) via linear way (42)
It is mounted movably along the direction in which 1) extends. An overhang (43) provided on a part of the slide base (21)
Belt (4) (45) (46) rotatably supported on the fixed base (13)
7) Adhere to (48) (see Fig. 2) and pulley (46)
And coaxially connected to a stepping motor (49) which is a drive source for upper and lower gripper feed.

In this transfer apparatus, the transfer rail (1
1) A clamper unit (5) for positioning the lead frame (12) at the silver paste supply position (P) and the pellet mount position (Q) (two locations in FIG. 1) above.
0) is arranged.

The clamper unit (50) moves the clamper block (53) vertically through a linear way (52) to a unit base (51) erected on a fixed base (13) as shown in FIG. The clamper (54) is attached to the lower end of the clamper block (53) so as to press a part of the lead frame (12) on the transport rail (11). On the other hand, the clamper block (53)
A roller (55) is rotatably supported on the upper end of the unit, and a spring (56) is stretched between the clamper block (53) and the unit base (51), so that the elasticity of the spring (56) is increased. The roller (55) is always in contact with the link lever (16) of the link mechanism (15) by urging the clamper block (53) downward by force.

A series of operations including a grip operation, a feed operation, and a clamper operation of the lead frame (12) of the transport device having the above-described configuration will be described in detail below.

First, the link mechanism (15) connected to the cylinder head (18) is operated by projecting and retracting the cylinder head (18) of the cylinder (14).
In the link mechanism (15), when the cylinder head (18) projects and retreats, the link lever (16) moves the link arm (1).
With the rotation about the fulcrum (a) of 7), the robot moves up and down with a slight forward and backward movement.

The vertical movement of the link lever (16) activates the vertical gripper unit (20). That is, the rotation of the roller (26) around the fulcrum (b) of the L-shaped arm (23) through the roller (24) fitted in the long hole (25) of the link lever (16) causes the roller (26) to slightly move. It moves back and forth with vertical movement. Since the roller (26) is fitted in the long hole (29) of the cam block (28), the cam block (28) moves back and forth with respect to the unit base (22) via the linear way (27). . At this time, a slight vertical movement of the roller (26) is absorbed by the long hole (29) of the cam block (28), and the movement of the cam block (28) is only a forward and backward movement. The upper and lower grippers (36) and (37) execute predetermined operations described below with the cam (31) at the tip of the cam block (28) by the forward and backward movement of the cam block (28).

First, the upper and lower grippers (36) and (37) of the upper and lower gripper blocks (32) and (33) via the cam followers (38) and (39) which come into contact with the cam surface (30) by the forward and backward movement of the cam (31). ) Moves up and down at a timing according to the shape of the cam surface (30). Specifically, upper gripper (36)
Moves downward by the elastic force of the spring (40) and closes, and rises and opens by the forcing force of the cam (31). Conversely, the lower gripper (37) moves upward by the force of the cam (31) and closes, and moves downward by the elastic force of the spring (41) to open.

That is, in the upper and lower gripper units (20) shown in FIG. 2, the upper and lower grippers (36) and (37) are in a state of holding the lead frame (12). At this time, the cam follower (38) of the upper gripper (36) is at the lowermost position of the cam surface (30), and the upper gripper (36) is urged downward by the elastic force of the spring (40) so that the lead frame (12 ) Is pressed from above. However, in this state, since the pressing force of the upper gripper (36) is applied to the lead frame (12), the cam follower (38) is slightly floating above the cam surface (30). On the other hand, the cam follower (39) of the lower gripper (37) is at the uppermost position of the cam surface (30), and the lower gripper (37) resists the elastic force of the spring (41) by the forcible force of the cam (31). It is urged upward and is in contact with the lead frame (12) from below.

As described above, when the cam (31) moves back and forth from this state and moves to the left in the drawing, the upper gripper (36)
The cam follower (38) rises from the lowermost position along the cam surface (30), so that the upper gripper (36) is pressed against the elastic force of the spring (40) by the forcing force of the cam (31). ) Rises and is released from the lead frame (12). On the other hand, as for the lower gripper (37), the cam follower (39) descends from the uppermost position along the cam surface (30), so that the lower gripper (37) descends due to the elastic force of the spring (41). It is released from the lead frame (12). The opening operation of the upper and lower grippers (36) and (37) is completed when the respective cam followers (38) and (39) reach the uppermost and lowermost positions.
6) The closing operation of (37) is performed by the reverse operation of each component by moving the cam (31) in the opposite direction.

The opening / closing operation timing of the upper and lower grippers (36) (37) is determined by the shape of the cam surface (30).
For example, in the opening operation, as shown in FIG. 8A, the lower gripper (37) does not descend at the initial stage of the operation, and the upper gripper (36) rises before the lower gripper (37). Then, after the upper gripper (36) starts to rise, the lower gripper (37) starts to descend. This is because the upper gripper (36) is urged downward by the elastic force of the spring (40), so that the upper gripper (36) is at the same time as the lower gripper (37) or later than the lower gripper (37). When the opening operation is performed, the upper gripper (36) may be slightly lowered to apply stress to the lead frame (12). This is to prevent this. When adjusting the opening / closing operation timing of the upper and lower grippers (36) (37), it is only necessary to adjust the allocation position of the cam (31).

The closing operation of the upper and lower grippers (36) and (37) is as shown in the part (A) in the figure, and is performed between the opening operation and the closing operation described above (the part (A) in the figure). In the blank part (c) between the part (a) and the part (c), after the feed operation of the upper and lower grippers (36) and (37) described later, the upper and lower grippers (3)
6) (37) returns to the initial position, and after the above-mentioned closing operation (right part (d) of the part (a) in the figure), the feed operation by the upper and lower grippers (36) (37) is performed.

The feed operation of the upper and lower grippers (36) and (37) starts from a state where the upper and lower grippers (36) and (37) are closed to clamp the lead frame (12). In particular,
The pulley (44) is driven by the operation of the stepping motor (49).
(45) The timing belt (47) wrapped around (46)
(48) and slide the slide base (21) attached to the timing belt (47) to the linear way (42).
Is moved along the direction in which the transport rail (11) extends. By the movement of the slide base (21), the upper and lower grippers (36) and (37) of the upper and lower gripper unit (20) move, and the lead frame (12) is moved by a constant pitch.
At this time, in the upper and lower gripper units (20), L
Roller (24) and link lever (1
6) is in a connected state, but since the connecting structure is a structure in which the roller (24) fits into the long hole (25) of the link lever (16), the long hole (25) becomes an escape. I have. Thereafter, as described above, the upper and lower grippers (36) and (37) are opened, and the upper and lower grippers (36) and (37) are returned to the initial positions by operating in reverse to the above-described feed operation. By repeating this series of operations, the lead frame (12) is transferred at a constant pitch.

During the transfer of the lead frame (12), the clamper unit (50) operates to position the lead frame (12) at the silver paste supply position (P) and the pellet mount position (Q).

In the clamper unit (50), similarly to the above-described upper and lower gripper units (20), the link mechanism (1) is provided.
5) Operates via the upper and lower grippers (36) (37)
The clamper (54) operates completely in synchronism with the operation. That is, the clamper block (53) moves up and down via the roller (55) by the up and down movement of the link lever (16), and the clamper (54) of the clamper block (53) moves up and down. Specifically, when the link lever (16) is lowered, the clamper (5
4) is lowered to press and position the lead frame (12) while being urged downward by the elastic force of the spring (56). Conversely, the lift of the link lever (16) causes the clamper (54) to rise against the elastic force of the spring (56) and move away from the lead frame (12). At the silver paste supply position (P) and the pellet mount position (Q), silver paste is supplied onto the lead frame (12) in a state of being positioned by the clamper (54), and then semiconductor pellets are mounted. As shown in FIG. 8, the operation timing of the clamper (54) with respect to the upper and lower grippers (36) and (37) is such that when the upper and lower grippers (36) and (37) are opened, the clamper (54) is started together with the opening operation. Starts to descend, and conversely,
When the upper and lower grippers (36) and (37) are closed, the clamper (54) starts to rise before the upper and lower grippers (36) and (37) clamp the lead frame (12).

In the above embodiment, the case where the present invention is applied to a lead frame transfer device attached to a die bonder used in a pellet mounting step in the manufacture of a semiconductor device has been described, but the present invention is not limited to this. Of course, it is needless to say that the present invention can be applied to a transfer device for a strip-shaped member other than the lead frame.

[0033]

According to the present invention, both the upper and lower grippers are movable in the vertical direction, and when the upper and lower grippers are released from the band-shaped member, the upper and lower grippers are completely separated from the band-shaped member so that the upper and lower grippers are completely separated from the band-shaped member. Since the contact state can be ensured, it is possible to smoothly and reliably transfer the strip-shaped member. In addition, the upper and lower grippers can be opened and closed by a single drive source via a link mechanism by moving the cam in the direction of movement of the strip-shaped member, thereby ensuring a completely synchronized opening and closing operation of the upper and lower grippers, thereby improving reliability. Significantly improved. further,
The opening / closing operation timing of the upper and lower grippers is
During the opening operation, the upper gripper rises first, and then
As the ripper starts descending, the strip
This prevents unwanted stress from being applied to the material.
In this regard, the reliability is greatly improved.

[Brief description of the drawings]

FIG. 1 is a plan view showing an embodiment of a belt-shaped member conveying device according to the present invention.

FIG. 2 is a front view of the transfer device of FIG. 1;

FIG. 3 is a side view showing the upper and lower gripper units and the upper and lower grippers in the transfer device of FIG. 1;

FIG. 4 is a side view showing an upper and lower gripper unit and a lower gripper in the transport device of FIG. 1;

5A and 5B show a cam block of the upper and lower gripper units of FIGS. 3 and 4, wherein FIG. 5A is a front view thereof, and FIG.

FIG. 6 is a plan view showing a feed mechanism of the transfer device of FIG. 1;

FIG. 7 is a side view showing a clamper unit of the transfer device of FIG. 1;

FIG. 8 is a timing chart showing the operation timing of the upper and lower grippers and the clamper.

FIG. 9 is a schematic configuration and operation explanatory view showing a conventional example of a belt-plate-shaped member conveying device.

[Explanation of symbols]

 11 Conveyor rail 12 Strip-shaped member (lead frame) 14 Drive source (stepping motor) 15 Link mechanism 30 Cam surface 31 Cam 36 Upper gripper 37 Lower gripper

Claims (2)

(57) [Claims] 1. A strip-shaped member guided by a transport rail is clamped by an up / down gripper movable vertically in accordance with an opening / closing operation timing operated by a single drive source, and transported along the transport rail. Then, the gripper is returned to the initial position by reverse opening and closing operation timing, and the opening and closing operation timing is
The upper gripper rises first during the opening operation of the
A method for conveying a strip-shaped member, wherein the gripper starts to descend . 2. A belt-like member guided by a transport rail is sandwiched by upper and lower grippers movable vertically, and the upper and lower grippers are opened and closed by relative vertical movement. The opening / closing operation timing
When the upper and lower grippers are opened, the upper
A cam having a cam surface shaped to start lowering the lower gripper is provided, and a link mechanism for moving the cam along the transfer direction of the band-shaped member is provided, and a single actuation of the link mechanism is performed. A transport device for a strip-shaped member, comprising a driving source.