JP3240206B2 - Lead frame separation apparatus and method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus and method for separating lead frames, and more particularly, to an apparatus and method for separating and cutting out lead frames used in the manufacture of semiconductor devices one by one from a stacked state. .

[0002]

2. Description of the Related Art When a large number of lead frames used in the manufacture of a semiconductor device are sequentially cut and cut one by one from a stacked state and supplied to a subsequent process, as shown in FIG. The lead frame (2) was sandwiched.

That is, the chuck claws (1) are urged in a direction (close direction) toward each other by the elastic force of the spring (3),
The movement stroke is regulated by the elastic force,
Conversely, means (not shown) are provided in the direction (opening direction) apart from each other so that a force against the elastic force of the spring (3) acts.

[0006] As shown in FIG.
From the expanded state against the elastic force of the spring (3), the uppermost lead frame (2) is separated and cut out one by one from the stacked many lead frames (2). At this time, as shown in FIG. 5 (b), the chuck claws (1) are brought close to each other and locked to both side edges of the lead frame (2) with a movement stroke regulated by the elastic force of the spring (3). With the lead frame (2) sandwiched between the chuck claws (1), the chuck claws (1) are raised to separate and cut out the uppermost lead frame (2).

[0005]

By the way, in the conventional lead frame separating apparatus, when the lead frame (2) is sandwiched and gripped by the chuck claws (1) as described above,
The movement stroke of the chuck claw (1) is regulated by the elastic force of the spring (3). Therefore, chuck nail (1)
The lead frame (2) may become unstable when it is pinched, and if the width of the lead frame (2) is changed due to a change in the type of the lead frame (2), the chuck jaws (1)
If the moving stroke of the lead frame is not changed, there is a possibility that the lead frame (2) cannot be pinched because the moving stroke is insufficient, or the lead frame (2) is deformed because the moving stroke is too large. .

Therefore, in this case, the spring (3) for regulating the movement stroke of the chuck claw (1) is adjusted to be appropriate according to the width dimension of the lead frame (2). It has to be replaced according to the type of product, and it is necessary to prepare replacement parts, and it is necessary to carry out replacement work, and it has been difficult to quickly respond to the type.

Accordingly, the present invention has been proposed in view of the above-mentioned problems, and an object of the present invention is to provide a lead frame separating apparatus capable of promptly responding to lead frame types.

[0008]

As a technical means for achieving the above object, the present invention is a device for separating a plurality of thin plate-shaped lead frames from one another and separating the uppermost lead frame one by one sequentially. In the cutting device, two sets of chuck claws for elastically engaging the opposite side edges of the lead frame and gripping the lead frame in a horizontal state, and moving each set of chuck claws in a predetermined direction along the horizontal direction. A ball screw having a right-hand thread portion and a left-hand thread portion which are relatively close to and separated from each other by a stroke, a first pulse motor for rotating the ball screw in a forward / reverse direction, and a And a two-pulse motor.

In the method of the present invention, when a large number of thin lead frames are stacked and separated and cut out one by one from the topmost lead frame, two sets are provided on opposite side edges of the lead frame. The chuck pawls are digitally controlled to move closely together with a predetermined movement stroke to elastically lock and raise the chuck jaws by a small amount. Features.

[0010]

According to the present invention, the operation of the first pulse motor causes the chuck claws connected to the right and left threaded portions to be moved by the rotation of the ball screw so as to sandwich and hold the lead frame. By counting the generated pulses, the movement stroke of the chuck pawl can be accurately regulated, and the lead frame can be stably held by the chuck pawl, and leads having different width dimensions can be obtained. Even when the frame is sandwiched, the movement stroke of the chuck claw can be easily and accurately changed, and the type of the lead frame can be quickly adjusted.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a lead frame separating apparatus and method according to the present invention will be described with reference to FIGS.

In the lead frame separating apparatus shown in FIGS. 1 and 2, (11) is a stage in which a large number of lead frames (12) are stacked in close contact with each other and screwed to a vertically mounted ball screw (13). A motor (15) is connected to a lower shaft end of the ball screw (13) via a belt (14).

(16) A chuck claw arranged near the side of the uppermost lead frame (12) of the lead frame (12) stacked on the stage (11), and the lead is provided on the inner surface thereof. A gripping part (17) provided with irregularities for locking when the frame (12) is sandwiched, and a nut member (19) for hanging down the gripping part (17) via a leaf spring (18) Be composed. (20) is the lead frame (12)
Is a ball screw that is rotatably and reversibly rotatable by appropriate means along its width direction, one side of which is a right-hand thread portion (21) from the center position and the other side is a left-hand thread portion (22). The nut members (19) of the chuck claws (16) are screwed into these left and right thread portions (22) (21).

Incidentally, (23) is a lead frame (1
The supply rail fixedly arranged on the side of 2) serves as a transfer destination of the lead frame (12) gripped by the chuck claws (16).

A first pulse motor (24) is connected to the ball screw (20) via a belt (25), and is attached to the movable head (26) together with the ball screw (20). (27) is a base that supports the movable head (26) slidably along the horizontal direction coincident with the width direction of the lead frame (12) above the movable head (26), and extends from the fixed point (a). It is pivotally supported in the vertical direction with its fixed point (a) as a fulcrum.

(28) is a second pulse motor connected to the base (27) via a crank mechanism (29), and (30) is connected to a movable head (26) via a crank mechanism (31). This is a third pulse motor.

The operation of the lead frame separating apparatus shown in FIGS. 1 and 2 will be described with reference to FIGS.

First, as shown in FIG. 3A, a large number of lead frames (12) stacked on a stage (11)
The chuck claw (16) is brought close to the side of the lead frame (12) on the uppermost layer, and the chuck claw (16) is moved to move the lead frame (12) on the uppermost layer with the chuck claw (16). Pinch it. That is, the ball screw (20) is rotated via the belt (25) by the operation of the first pulse motor (24), and the chuck pawl is engaged via the nut member (19) screwed to the left and right screw portions (22) (21). (16) is moved by a predetermined stroke so as to approach. As a result, the side edge of the uppermost lead frame (12) is held by the gripper (1) of the chuck jaw (16).
7) Resiliently lock with the elastic force of the leaf spring (18).

Here, the movement stroke of the chuck jaw (16) is regulated by the rotation control of the first pulse motor (24), and the pulse generated by the first pulse motor (24) is counted. It is possible to set with high accuracy. Therefore, even if the width of the lead frame (12) is changed due to the type of the lead frame (12) as shown in FIGS. 4 (a) and 4 (b), the chuck jaws corresponding to the width of the lead frame (12) are changed. (16) Moving stroke S, S '
Since the setting can be changed with high accuracy only by changing the count value of the number of pulses from the first pulse motor (24), the type of the lead frame (12) can be quickly adapted.

The lead frame (12) is gripped by the chuck claws (16), and the base (27) is moved through the crank mechanism (29) by the operation of the second pulse motor (28).
Is swung in the vertical direction with the fixed point (a) as a fulcrum. As a result, the chuck pawl (16) is raised together with the first pulse motor (24) and the ball screw (20) via the movable head (26) on the base (27), thereby obtaining the state shown in FIG.
As shown in the figure, the side edge of the lead frame (12) locked to the grip portion (17) of the chuck claw (16) is lifted and bent, and the lead frame (12) of the uppermost layer is bent.
Can be easily separated from the lead frame (12) stacked immediately below.

By continuing to raise the chuck pawl (16), the uppermost lead frame (12) is completely separated and cut out as shown in FIG. 3 (c). ), The movable head (26) is slid onto the base (27) via the crank mechanism (31), and the lead frame (1) held by the chuck jaws (16) is moved.
2) is placed above the supply rail (23). Then, contrary to the above, the chuck claw (16) is lowered by the reverse operation of the second pulse motor (28), and the first pulse motor (2
The lead frame (12) is transferred onto the supply rail (23) by releasing the gripping state of the lead frame (12) by separating the chuck claws (16) by the reverse operation of 4).

Hereinafter, the stage (11) is raised by a constant pitch via the ball screw (13) by the operation of the motor (15), and the lead frame on the uppermost layer of the lead frame (12) stacked on the stage (11). By repeating the above-described series of operations while positioning (12) at a predetermined position, the lead frames (12) stacked on the stage (11) are reliably separated one by one from the top layer one by one. Can be cut out.

[0023]

According to the present invention, the movement stroke of the chuck pawl can be accurately regulated by the first pulse motor, and the lead frame can be stably gripped by the chuck pawl, and Even when a lead frame having a different width is sandwiched, the moving stroke of the chuck jaws can be easily and accurately changed, and the lead frame can be quickly adapted.

[Brief description of the drawings]

FIG. 1 is a front view showing an embodiment of a lead frame separating apparatus according to the present invention.

FIG. 2 is a plan view showing a movable head and a driving system of the lead frame separation device of FIG. 1;

FIG. 3 shows the operation of the lead frame separating device of FIG.
(A) is an enlarged front view showing a state in which the chuck pawl is locked to the lead frame, (b) is an enlarged front view showing a state in which the side edge of the lead frame is bent by raising the chuck jaw,
(C) is an enlarged front view showing a state where the lead frame is separated and cut out by raising the chuck claws.

FIGS. 4A and 4B are front views including a partly omitted portion for explaining a movement stroke of a chuck claw in two examples having different lead frame width dimensions.

FIG. 5 shows a conventional example of a lead frame separating apparatus,
(A) is a front view showing an opened state of the chuck claws, and (b) is a front view showing a state where the lead frame is sandwiched between the chuck claws.

[Explanation of symbols]

 12 Lead frame 16 Chuck jaw 20 Ball screw 21 Right thread 22 Left thread 24 First pulse motor 28 Second pulse motor

Claims (2)

(57) [Claims] An apparatus for sequentially separating and cutting out the uppermost lead frame one by one from a state in which a number of thin plate-shaped lead frames are stacked, wherein the lead frame is elastically engaged with opposing side edges of the lead frame. Two sets of chuck claws for gripping the lead frame in a horizontal state, a ball screw having a right-hand thread part and a left-hand thread part for relatively closely separating each set of chuck claws by a predetermined moving stroke along the horizontal direction, and A lead frame separating apparatus comprising: a first pulse motor for rotating a ball screw forward and backward; and a second pulse motor for moving up and down a unit including the chuck pawl, the ball screw, and the first pulse motor. 2. A method of digitally controlling two sets of chuck claws on opposite side edges of a lead frame in order to separate and cut out the uppermost lead frame one by one from a state in which many thin plate-shaped lead frames are stacked. The lead frame is elastically locked by being brought close together with a predetermined moving stroke and raised by a very small amount, and the both sides of the lead frame are lifted up by a very small amount with chuck claws and separated while being bent. Separation method.