JPH01252437A - Lead frame transporting mechanism - Google Patents

Abstract

PURPOSE:To prevent the trouble of exfoliation and disconnection of a wire by nipping the gap part of an element at one edge part of a lead frame by the upper and lower hooks of the second hook supporting body in the thickness direction and loading the edge part onto the lower hook of the first hook supporting body and transporting said edge part. CONSTITUTION:A pushing-out arm 36 is shifted in the state where the rod of a cylinder 29 is projected, and lead frames L are pushed out one by one from a magazine M at the P1 position, and correctly positioned. Then, the upper and lower hooks 51A and 51B are opened, and the first hook supporting body 42 is shifted to a turntable 4 side, and the gap part of a lead frame element is nipped between the hooks 51A and 51B, and the supporting body 42 is shifted to the second hook supporting body 43 side, and the lead frame L is pulled out from the magazine M, and the gap part of the element is nipped by the hooks 51A and 51B of the supporting body 43 and fixed. The hooks 51A and 51B of the supporting body 42 are opened, and returned to the original position. Therefore, the lead frame is hardly applied with a stress, and the trouble of exfoliation or disconnection of a wire can be effectively prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to a transport mechanism for horizontally extracting lead frames stacked and stored in a magazine and transporting them to the next process such as a molding device.

"Prior art" For example, in a transfer molding device that forms a resin package on a lead frame after wire bonding, a conveyance mechanism is installed to automatically feed the lead frame into the mold according to the molding cycle. There is.

Conventionally, as this type of conveyance mechanism, a structure in which a pair of support claws sandwich both sides of the central portion of a lead frame placed in a horizontal state, and the support claws are moved has been frequently used.

"Problem to be Solved by the Invention" However, in the above-mentioned conveyance mechanism, both edges of the lead frame are pinched with enough force to prevent the lead frame from falling, so it is inevitable that the lead frame will bend slightly in the width direction. The stress at that time may cause tension to be applied to the wire, resulting in peeling of the joint surface or breakage of the wire, which is becoming more important as wires become thinner.

Further, in the above mechanism, when the dimensions of the lead frame are changed, the dimensions of the support claws and the locking width must be reset each time, and there is also a problem that the mechanism lacks versatility.

"Means for Solving the Problems" The present invention has been made to solve the above problems, and includes a first claw support body and a second claw each including an upper claw and a lower claw that extend horizontally and are operable to open and close. The present invention is characterized in that it is provided with a support and a driving means capable of moving each of the claw supports separately so that the claws of the claw supports maintain positions of opposing sides of a rectangle on the same horizontal plane.

"Function" In the transport mechanism of the present invention, the upper claw and lower claw of the second claw support horizontally sandwich the element gap at the front end of the lead frame, and the upper claw and lower claw of the first claw support are opened. hand,
The rear end portion of the lead frame is placed horizontally on the lower claw, and in this state, each claw support is moved in the same direction to convey the lead frame. As a result, stress is less likely to be applied to the lead frame than when the lead frame is transferred by being held in the width direction by support claws, and troubles such as wire peeling and wire breakage can be prevented.

"Example" Hereinafter, a transfer molding apparatus employing an example of a lead frame transport mechanism according to the present invention will be described with reference to the drawings.

First, an outline of the entire molding apparatus will be described using FIGS. 1 to 5. 1 Figure 1 is a front view of the device, Figure 2 is a plan view, Figure 3 is a right side view, Figures 4 and 5 are a right side view and a left side view with the cover attached. The front, rear, left, and right directions used in the description correspond to the state in which the device is viewed from the front.

Reference numeral 1 in the figure denotes a magazine mounting table fixed on the base 2, on which a plurality of rectangular parallelepiped magazines M are placed side by side at equal intervals. Further, 3 is a magazine transfer mechanism that lifts the magazines M one by one from the mounting table 1 and transfers them onto the turntable 4.

The turntable 4 is capable of mounting the magazine M eccentrically from the center of the rotating wheel, and for convenience of explanation, a position near the magazine mounting table 1 (Pi in the figure) is the mounting position, and the opposite side (P2) is the mounting position.
is called the half-turn position. Reference numeral 5 denotes a frame extrusion mechanism, which extrudes one lead frame L from the magazine M located at Pl or P2. The extruded frame is transferred into the transfer mold 8 by the frame transfer mechanism 6 together with the resin tablets T, which are sequentially supplied from the tablet supply mechanism 7. A cleaning mechanism 9 is provided behind the transfer mold 8 for cleaning the opposing surfaces of the upper mold and the lower mold.

Then, the lead frame L with a cull on which the resin package is formed by the transfer mold 8 is separated from the cull by a gate break mechanism 10, and the lead frame L with a cull is separated from the cull by a gate break mechanism 10.
This allows them to be stored in the rack 12 one after another.

Next, using FIGS. 6 to 11, the magazine transfer mechanism 3, turntable 4, and
The frame extrusion mechanism 5 and the frame conveyance mechanism 6, which is the main part of the present invention, will be explained in detail. As shown in Fig. 6, the magazine M has many horizontal 11113A inside.
It consists of a pair of side plates 13 having a
A predetermined number of lead frames L are stored in a stacked manner along line 3A.

As shown in FIG. 7, above the magazine M on the mounting table 1, a ball screw 15 extending beyond the turntable 4 is arranged horizontally, and its front end is connected to a stepping motor 16. .

A chuck support 18 is attached to this ball screw 15 via a ball nut 17, and this chuck support 18 slides along a horizontal rail 21 supported by a fixed plate 20 via rail receivers 19 at both ends. It is said that it is possible to move.

An air cylinder 22 is fixedly fixed to the chuck support 18 by penetrating it downward at the center thereof, and guide bars 23 are vertically and slidably passed through the chuck support 18 at both ends thereof, and the rod of the air cylinder 22 and each guide bar are inserted into the chuck support 18 . An elevating plate 24 is fixed to the lower end of 23. This elevating plate 24 has an air chuck 25 provided with a pair of pinching claws 25A facing downward.
is fixed, and the upper end of the center portion of the magazine M is held between the two by supplying air.

On the other hand, the turntable 4 is fixed horizontally on an air rotation driver 26 as shown in FIG. It is rotated 180° forward and backward by air supply, and raised and lowered with high precision. Further, on the top surface of the turntable 4, a mounting position P1 and a half-rotation position P are provided.
A partition 4A separating the two is fixed.

Next, the lead frame extrusion mechanism 5 will be explained.

As shown in FIG. 7, an extrusion support plate 28 is arranged in front of the turntable 4 along the longitudinal direction of the magazine M, and is directed toward the turntable 4 by an air cylinder 29 fixed on the base 2. The guide bar 30 can be moved forward and backward along a pair of guide bars 30. Pole screws 32 are supported in parallel at both ends of the extrusion support 28 via bearings 31, and are rotationally driven by a stepping motor 33. An arm support 35 is attached to this pole screw 32 via a pole nut 34,
It is allowed to slide along a guide bar (not shown).

An arm 36 consisting of a horizontal portion 36A and a vertical portion 36B extending downward from the tip thereof is attached to the arm support 35, and when the pole screw 32 is rotated with the rod of the cylinder 29 protruding, When the lower end of the arm vertical portion 36B pushes out one lead frame L from the magazine M located at Pl (see Fig. 8), on the other hand, when the rod of the cylinder 29 is retracted, the lead frame L is pushed out from the magazine M located at P2. It is configured to push out one sheet.

Next, the frame transfer mechanism 6 will be explained.

As shown in FIGS. 10 and 11, from the vicinity of the turntable 4, there are two
A book guide bar 40 is arranged in parallel and passes behind the mold 8 and is fixed at the right end of the device. Further, two pole screws (driving means) 41 are supported in parallel with these guide bars 40, and are each driven by separate stepping motors (paths shown).

A first pawl support 42 and a second pawl support 43 are attached to the guide bar 40 and the ball screw 41 in order from those closest to the turntable 4. These claw supports 42 and 43 are L-shaped, and the guide bar 40 and pole screw 41 are inserted into the vertical portions thereof.
It is engaged with only one ball screw 41 via a pole nut 44. Therefore, the first claw support 42
and the second pawl support 43 are driven by separate ball screws 41, respectively.

A servo motor 45 is fixed to the right side surface of each pawl support 42, 43, and a pinion 46 is fixed to the rotation shaft of this servo motor 45.

Also, in the horizontal portion of each claw support 42, 43, a pair of rack members 47 are provided with posts 48, respectively, as shown in FIG.
Each rack member 47 is engaged with the upper and lower ends of the pinion 46, respectively.

Further, each of these rack members 47 has a twin rod cylinder 49 fixed downwardly at one end thereof, and the other end thereof is inserted into a cylinder 50 horizontally fixed to the twin rod cylinder 49 on the opposite side. . This results in
When the pinion 46 is rotated in the direction of the arrow in the figure, each twin rod cylinder 49 simultaneously opens and closes to the position indicated by the two-dot chain line in the figure.

At the lower end of the rod of each twin rod cylinder 49, chuck cylinders 52 having horizontally extending upper claws 51A and lower claws 51B are attached facing each other. Then, when air is supplied to each chuck cylinder 52 while the rod of the twin rod cylinder 49 is lowered, the upper claw 51A and the lower claw 51B approach each other and close, and the closed surface is at the height of the mold dividing surface PL. It is now consistent with the

A tablet transfer mechanism 53 is also provided on the lower surface of the second claw support 43. This tablet transfer mechanism 53 sandwiches a plurality of tablets T arranged in a row on a tablet mounting table 54 by a tablet supply mechanism 7 between a pair of clamp plates 55, and holds a lead frame L in this state.
At the same time, it is transferred into the mold 8 and dropped into a resin pot formed in the lower mold.

Next, how to use the above device will be explained.

In this transfer device, as shown in FIG. 7, first, the pole screw 15 is rotated to move the chuck support 18 onto the magazine M on the mounting table L, and the air cylinder 22 is operated to lower the air chuck 25. Let the pinching claws 25A
Hold the magazine M with.

Next, the magazine M is lifted and moved to the mounting position P1 of the turntable 4, and the magazine M is mounted there.

Once the magazine M is loaded in this manner, the height of the turntable 4 is adjusted as necessary so that the lower end of the push-out arm 36 is slightly lower than the lead frame L located at the top within the magazine M. Then, with the rod of the cylinder 29 protruding, the extrusion arm 36 is moved to extrude one lead frame L from the magazine M located at Pl, and the tip of this lead frame L is inserted into the closed position of the first claw support 42. Stop by lightly touching the sides of the upper claw 51A and lower claw 51B. Through this operation, the lead frame L is accurately positioned.

Next, open the upper claw 51A and lower claw 51B that are in contact with the lead frame L, move the first claw support 42 to the turntable 4 side, and lead between the upper claw 51A and the lower claw 51B. The frame L is passed through for a predetermined length and inserted into the gap between the elements. Then, in this state, the first claw support 42 is moved to the second claw support 43 side, and the lead frame L is completely pulled out from the magazine M.
The lead frame L is passed by a predetermined length between the claws 51A and 51B, and the gap between the elements is held between the claws 51A and 51B and fixed. Then, the claw 51 of the first claw support 42
Open A and 51B and return them to their initial positions.

Next, the turntable 4 is rotated half a turn by the air rotation drive device 26 to move the magazine M to the half rotation position P2, and then the turntable 4 is moved to the magazine M by the lifting drive device 27.
It is raised by the distance between the stacked lead frames L in the stack. Then, the rod of the cylinder 29 is moved backward, the push-out arm 36 is moved again, and the lead frame L on the -set is pushed out in the same direction as above from the magazine M at the half-rotation position P2. Then, by performing the same operation as for the first piece with the claws 51A, 51B, etc. on the opposite side, finally both the claws 5 of the second claw support 43 are
1A and 51B, sandwich one lead frame L each, and connect the other ends of these lead frames L to the first
It is supported by each lower claw 51B of the claw support body 42.

After supporting the two lead frames L in this way, all the twin rod cylinders 49 and 49 of each claw support 42 and 43 are supported.
The rods . After simultaneously moving the second claw support 43 and the first claw support 42 onto the lower mold of the mold 8, each chuck cylinder 52 is further lowered to open the positioning hole formed in the lead frame L. , and fit into the positioning protrusion formed on the upper surface of the lower mold. And the winter melons 51A, 51 of the second nail support 43
After opening B, energize each servo motor 45 to remove winter melon 5.
1A and 51B are opened to both sides, each lead frame L is released, and setting to the lower mold is completed.

When the above one cycle is completed, the turntable 4 is raised again by the lead frame stacking interval in the magazine M and rotated half a rotation, and the above cycle is repeated from the beginning.

In addition, when the magazine M becomes empty, the magazine transfer mechanism 3 is activated to return the empty magazine M that was moved to the mounting position PI onto the mounting table l where it was originally located, and a new one is transferred from the mounting table l. Carry the magazine M and place it on the loading position Pi,
Continue cycle.

According to the lead frame transport mechanism described above, one end of the lead frame L is connected to the upper claw 51A of the second claw supporter 43.
Since the lead frame L is sandwiched in the thickness direction by the lower claws 51B and the other end is supported by being placed on the lower claws 51B of the first claw supporter 42, the lead frame L is not bent in both the width direction and the longitudinal direction. Compared to conventional conveyance mechanisms that sandwich the lead frame in the width direction, it is possible to effectively prevent troubles such as stress being applied to the lead frame and wires peeling off or breaking.

In addition, since the lead frame is horizontally held between the upper and lower claws, even if the dimensions of the lead frame are changed, it is not necessary to change the dimensions of the claws or the amount of opening/closing operation as with conventional transport mechanisms. It has very little and is highly versatile. Further, in this example, since the lead frame is conveyed by a ball screw whose movement amount can be arbitrarily set, it has the advantage that lead frames of any size can be easily accommodated by simply changing the operation program.

In the above embodiment, each of the claw supports 42 and 43 was moved horizontally along the same guide par 40, but it is also possible to move them in parallel in a vertical direction or an inclined direction.

Further, the configuration and operation of other parts may be changed as necessary.

"Effects of the Invention" As explained above, in the lead frame transport mechanism of the present invention, the element gap portion at one end of the lead frame is sandwiched in the thickness direction by the upper and lower claws of the second claw support, and Since the end portion is placed on the lower claw of the first claw support and transferred in a horizontal state, the lead frame does not bend in either the width direction or the longitudinal direction. It is possible to effectively prevent troubles such as stress being applied to the lead frame and tension being applied to the wires resulting in peeling or disconnection compared to the transport mechanism. Further, even when the dimensions of the lead frame are changed, there is almost no need to change the dimensions of the claws or the amount of opening/closing operation, unlike in conventional transport mechanisms, and the device is highly versatile.

[Brief explanation of the drawing]

1 to 5 show the overall outline of a transfer molding apparatus employing an example of the lead frame conveyance mechanism according to the present invention, in which FIG. 1 is a front view, FIG. 2 is a plan view, and FIG.
The figure is a right side view, and FIGS. 4 and 5 are a right side view and a left side view with the cover attached. Further, FIG. 6 is a perspective view of the magazine, FIG. 7 is a plan view showing the magazine transfer mechanism and frame extrusion mechanism, FIGS. 8 and 9 are side views and front views showing the magazine transfer mechanism, and FIGS. FIG. 11 is a plan view and a side view showing the lead frame transport mechanism, which is the main part of the present invention. L...! J-F7 frame, M...magazine, 6...
・Lead frame transport mechanism, 40... Guide bar, 4
1... Ball screw (drive!!! purchased), 42...
- First claw support, 43... Second claw support, 45...
Servo motor, 46... Pinion, 47... Rack member, 49-... Twin rod cylinder, 51A...
Upper jaw, 51B...Lower jaw, 52...Chuck cylinder.

Claims (1)

[Claims] A first claw support and a second claw support each having an upper claw and a lower claw that extend horizontally and are operable to open and close, and each claw of these claw supports maintains positions of opposing sides of a rectangle on the same horizontal plane. A lead frame conveyance mechanism characterized in that the lead frame conveyance mechanism is provided with a drive means capable of moving each claw support separately.