JPH0582970B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (A) Field of Industrial Application The present invention relates to semiconductor manufacturing equipment, and more particularly to a lead frame conveyance device for transporting and positioning a lead frame during die bonding, wire bonding, and the like.

(b) Conventional technology Conventionally, a lead frame is transported by inserting a feed claw into a pilot hole etc. provided in the lead frame.
The feed claw was driven by a cam, etc. to transport the lead frame. Although this method has the advantage of not causing feed deviation, it requires work such as replacing the pawl and changing the position of the pawl every time the diameter of the pilot hole or the position of the hole changes, and the equipment has to be stopped during this time. There is a problem in that it causes a decrease in productivity. Therefore, in Japanese Patent Application Laid-Open No. 59-161809, the widthwise end of a lead frame placed on a fixed chute is held by a fixed claw on the upper surface and a movable claw moving from below on the lower surface, and the lead frame is placed on a fixed chute. It is raised above the surface and transported downstream.

However, when this grip is released after transportation and the lead frame is placed on a fixed chute, the claws that support the top surface are fixed, so the lead frame is supported only by the movable claws for the space between the transport level and the chute surface. It is unstable as it will fall. Furthermore, when placed on the fixed chute, there is a possibility that shocks and vibrations will be applied, which may cause the lead frame to become misaligned.

(c) Problems to be solved by the invention Therefore, an object of the present invention is to enable reliable transfer of a lead frame onto a fixed chute without causing shock or vibration. shall be.

(d) Means for Solving the Problems Therefore, the present invention has an upper claw portion that presses the lead frame toward the fixed chute, and the upper claw portion pushes up the lead frame pressed against the fixed chute above the chute. a lower claw portion that clamps the frame with an upper claw portion; a conveying means for conveying the upper claw portion and the lower claw portion in the longitudinal direction of the frame while holding the lead frame; The lead frame is further provided with a release means for releasing the lead frame from being held by the upper claw portion and the lower claw portion after the frame is placed on the chute.

(E) Effect With the above structure, the upper claw portion descends onto the lead frame placed on the fixed chute and presses the frame against the fixed chute. The lead frame pressed against the fixed chute by the upper claw is raised by the lower claw and pushed up above the chute while being held between the upper claw and transported in the longitudinal direction of the frame by the transport means. When the lead frame is placed on the chute after being conveyed, the release means releases the frame from being held by the upper claw portion and the lower claw portion.

(F) Embodiments The lead frame conveying device of the present invention will be explained with reference to the drawings. Fig. 1 is a view of the lead frame conveying device of the present invention from the conveying direction, and Fig. 2 is a view of the lead frame conveying device of the present invention. FIG. 3 is a side view from the left side of FIG. 1, but the upper and lower holders shown in FIG. 2 are originally sliding fulcrums. Although it is loosely fitted into the text, it has been omitted. Figures 4 and 4 are both views from above of the lead frame conveying device of the present invention, figure 4 is a view with the upper claw portion omitted, Figure 5 is a schematic diagram showing the origin state of the device of the present invention, and Figure 6 is the upper claw. A diagram showing the state in which the part is pressed against the lead frame,
FIG. 7 is a diagram showing the conveyance state of the lead frame, and FIG. 8 is a schematic diagram illustrating the positions of the loose fitting portion and the lever during conveyance of the lead frame.

1 to 8, the drawing numbers and configuration will be explained. 1 is a lead frame, 2 is an upper claw, 3 is a lower claw, 4 is a straight vertical slide guide to which the upper claw is attached, and 5 is the lower claw. 6 is a mounting plate for mounting the linear vertical slide guides for the upper and lower claws, and 7 is the first linear vertical slide guide for the upper claws.
8 is a stopper bolt that is attached to the first member and can come into contact with the upper surface of the mounting plate when the upper claw is lowered; 9 is a fixed chute on which the lead frame is placed; 10 is a guide. axis, 11
12 is a second member attached to the linear vertical slide guide of the upper claw, and 13 is attached to the second member. 1st
A bolt 14 is a second bolt attached to the slide guide in the conveying direction, and a bolt 15 is fixed to the first bolt and the second bolt, respectively, and the second member and the upper claw are connected to each other. A first tension spring that urges the upper claw downward via a linear vertical slide guide, 16 a third member attached to the second member, 17 a feed screw shaft for conveyance, and 18 a conveyance screw shaft; Nut for the feed screw shaft into which the feed screw shaft is screwed, 1
Reference numeral 9 denotes a connecting plate connecting the slide guide in the transport direction and the feed screw shaft nut, 20 a fourth member attached to the connecting plate, and 21 a first member provided on the fourth member as a fixed fulcrum. , 22 is a swinging lever rotatably supported by the fourth member about the first fulcrum, and 23 is press-contactable to a third member attached to the end of the swinging lever. A first roller 24 is a second fulcrum provided on the swinging lever, and 25 is a roller whose one end is rotated about the second fulcrum as the swinging lever rotates about the first fulcrum. 26 is a second roller as a sliding fulcrum attached to the lever, and 27 is a rod that moves vertically in a straight line and has its other end attached to the linear vertical slide guide of the lower claw; Second
28 is a cam follower; 28 is a cam follower; 28 is a cam follower;
29a and 29b are vertical slide parts to which the cam follower is attached and the upper and lower holders are attached;
Reference numeral 30 denotes a guide for the vertical slide portion, and 31 denotes a cam that transmits the rotational force of the lever about the first fulcrum to the lever via the cam follower, the vertical slide, and the vertical holder (however, in the figure, the cam is a guide for the vertical slide section). 32 is the third bolt attached to the lever, 33 is the fourth bolt attached to the connecting plate, and 34 is the third bolt attached to the lever.
and a fourth bolt, and in order to prevent the second roller from collapsing in the upper and lower holders, the lever is biased counterclockwise, and the second roller is rotated. The second tension spring 35, which is brought into pressure contact with the inner and lower surfaces of the upper and lower holders, is a heater block.

Next, to explain the operation of the lead frame conveying device of the present invention, FIG. 5 shows the origin state of the upper and lower claw portions of the device of the present invention. Let the thickness of the lead frame 1 and the stroke of the lower claw 3 be α, and the stroke of the upper claw 2 be β. If the distances from the first fulcrum 21 to the second fulcrum 24 and the first roller of the lever 22 shown in FIG. 8 are ₁ and ₂ , respectively, β=(
_2/1 ) α, where ₁ , ₂ so that β _> α
Set.

In the state shown in FIG. 5, the upper claw 2 is at the upper limit position, the lower claw 3 is at the lower limit position, and the lead frame 1 is completely released. The upper limit level of the lower claw 3 is set at γ above the A side, and the lead frame 1 is conveyed at the upper limit level adjusted by the rod 25.
This means that the bottom surface of lead frame 1 is in contact with surface A,
This is to prevent resistance from occurring. Note that the first tension spring 15 shown in FIG. 5 is originally located further down.

Here, after the movable chute side of the fixed chute 9 is opened, the upper and lower holders 27 rise as shown in FIG. If the upper claw 2 is raised by ₁ , the upper claw 2 is lowered by β ₁ =( ₂ / ₁ ) α ₁ due to the biasing force of the first tension spring 15 . At this time, the stopper bolt 8 is adjusted so as to stop the upper claw 2 from descending, and is brought into contact with the mounting plate 6. As shown in FIG. 7, as the upper and lower holders 27 rise, the lever 22 rotates clockwise about the first fulcrum 21, and the lower claw 3 further rises through the remaining stroke (α-α ₁ ). However, the upper claw 2 is stopped from lowering by the stopper bolt 8. In a state where the lead frame 1 is raised by γ from the A side and is held between the upper claw 2 and the lower claw 3,
The feed screw shaft 17 for conveyance starts rotating by the drive of a pulse motor or servo motor (not shown) as a driving means for driving the lead frame in the longitudinal direction, and the nut 18 for the feed screw moves a predetermined stroke in the conveyance direction. Accordingly, the upper claw 2 and the lower claw 3 are also moved while holding the lead frame 1, and the lead frame 1 is conveyed at a predetermined pitch, and the island position of the frame 1 is die bonded or wire bonded. move to position. Note that α−α ₁ −γ＞ο,ο
Let <γ<t.

FIG. 8 shows the lever 2 during transportation in the state shown in FIG.
2, and β ₂ is the value obtained by subtracting β ₁ from β=( ₂ / ₁ ) α, which corresponds to the stroke α of the lower claw 3 at the upper limit. In other words, the actual stroke of the upper claw 2 is _β1 . In addition, since the second roller 26 slides within the upper and lower holders 27 when the lead frame 1 is transported, the loose fitting portion in the upper and lower holders 27 at the fixed position must be larger than the transport stroke.

When the upper claw 2 and the lower claw 3 reach the conveyance completion position, the upper and lower holders 27 descend, the lever 22 rotates counterclockwise, and the lower claw 3
is lowered to the A side, the fixed chute 9 is closed, and the lead frame 1 is placed on the fixed chute 9. The clamping of the lead frame 1 is then completed by raising the heater block 35 to support the lead frame 1 from the back surface and lowering the frame presser from the top surface. At this time, even if the lower claw 3 descends to the A side, the upper claw 2 does not rise because there is a gap between the third member 16 and the first roller 23. When the lower claw 3 descends to the position shown in FIG. 6, the first roller 23 comes into contact with the third member 16, and the upper claw 2 starts to rise, completely removing the lead frame 1 shown in FIG. It rises to the released state. At the same time, the conveying feed screw 17 rotates in the opposite direction, causing the feed screw nut 18 to return by the amount of pitch feed described above, and the upper claw 2 and lower claw 3 also return to their original positions accordingly.

The vertical holder 27 is raised and lowered by a motor (not shown) as a driving means for driving the cam 31.
This is done by The above is one transport cycle of the lead frame transport device of the present invention.

(G) Effects of the Invention As described above, according to the present invention, in order to keep the lead frame in a clamped state from the start to the completion of transport, that is, during the clamping operation before the start of transport, the upper claw portion is lowered onto the lead frame. While pressing the lead frame against the fixed chute, the lower claws are raised to clamp the lead frame, and when the clamping is released after conveyance is completed, the lead frame is lowered while being clamped between the upper and lower jaws, and the frame is After being placed on the chute, the lead frame is released from being held by the upper and lower claws, thereby preventing the lead frame from shifting due to shocks, vibrations, etc. when placed on the fixed chute.

[Brief explanation of the drawing]

FIG. 1 is a view of the device of the present invention as viewed from the transport direction, FIG. 2 is a view showing the upper and lower holders and cam mechanism of the device of the present invention, and FIG. 3 is a left side view of the device of the present invention in FIG. 1.
FIG. 4 is a top view of the device of the present invention, FIG. 5 is a diagram showing the original state of the device of the present invention, FIG. 6, FIG. 7 is a diagram showing the device of the present invention in a certain state of operation, and FIG. It is a drawing showing the position of a lever. 1... Lead frame, 2... Upper claw, 3... Lower claw, 9... Fixed chute, 21... First fulcrum,
22... Lever, 23... First roller, 26...
...Second roller, 27...Upper and lower holder, 31...
…cam.

Claims (1)

[Claims] 1. An upper claw part that presses the lead frame toward the fixed chute, and a lower claw part that pushes up the lead frame pressed against the fixed chute above the chute and clamps the frame with the upper claw part. and a conveying means for conveying the upper claw part and the lower claw part in the longitudinal direction of the frame while holding the lead frame between them, and placing the frame conveyed to a predetermined position by the conveying means on the chute. and a release means for releasing the lead frame from being held by the upper claw part and the lower claw part after the lead frame is moved.