Method and apparatus for carrying and locating sheet frame

In order to efficiently carry and locate a plurality of types of sheet frames having different dimensions, it is possible to change and adjust positions of lower guide rails in response to a width of a supplied lead frame in a shorter-side direction (X). A carrier device and a stop device can adjust and change a carriage distance in a carriage direction and a stop position in response to a longitudinal width of the lead frame respectively. Thus, it is possible to carry and locate sheet frames in response to various dimensions thereof.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to a technique of carrying and locating a 
sheet frame, which is employed for transferring a lead frame having a 
resin-molded semiconductor device from a step to another step in steps of 
fabricating a semiconductor device, for example. 
2. Description of the Background Art 
&lt;Structure of the Prior Art&gt; 
Steps of fabricating a semiconductor device include a step of molding a 
semiconductor chip which is mounted on a lead frame with resin and a step 
of molding a subsequent lead frame. Between these two steps, it is 
necessary to carry the preceding lead frame from the former step to the 
latter step while locating the same at a prescribed position. FIGS. 13 and 
14 are a plan view and a front elevational view showing a sheet frame 
employed for such a purpose. 
Referring to these figures, a lead frame 1 having a prescribed width and a 
prescribed length is mounted on a lower rail 21 which is provided on a 
sheet frame carrying-and-locating apparatus 2. A completely resin-molded 
semiconductor device 1a is integrated in the lead frame 1. Guide bars 21a 
are fixedly mounted on the lower rail 71 while a pair of upper rails 22a 
and 22b are slidably supported by the guide bars 21a to be movable along a 
horizontal shorter-side direction X of the lead frame 1. A pair of fixed 
upper rails 23a and 23b are provided on the lower rail 21 adjacently to 
the upper rails 22a and 22b. Guide spaces 24, which are clearances for 
guiding the lead frame 1, are defined between the pair of upper rails 22a 
and 22b, being most approached to each other in closed states, and the 
lower rail 21. Similar guide spaces 24 are also defined between the pair 
of fixed upper rails 23a and 23b and the lower rail 21. 
The apparatus 2 is provided with a pair of drive units 25, which are 
adapted to drive the pair of upper rails 22a and 22b in the shorter-side 
direction X respectively to bring the same into separated (open) states or 
closed states at need. The apparatus 2 further comprises a carrier 26 for 
carrying the lead frame 1, whose end portions are stored in the guide 
spaces 24, in a horizontal carriage direction Y, shown by arrow in FIG. 
13, longitudinally along the lead frame 1 with a prescribed distance, a 
drive unit 27 for driving the carrier device 26, a stopper 28 for stopping 
the as-carried lead frame 1 at a prescribed position, and a drive unit 29 
for upwardly and downwardly driving the stopper 28. 
&lt;Operation of the Prior Art&gt; 
The conventional apparatus 2 operates as follows: First, the drive units 25 
so operate that the pair of upper rails 22a and 22b are guided by the 
guide bars 21a to slide in directions to be separated from each other 
(open directions), to enter open states. Then, the lead frame 1 is placed 
on the lower rail 21 by action of a supplier (not shown) from above the 
lower rail 21. Thereafter the upper rails 22a and 22b slide toward each 
other along the shorter-side direction X, to enter closed states. At this 
time, the upper rails 22a and 22b define the guide spaces 24 with the 
lower tail 21, to hold cross-directional end portions of the lead frame 1 
therein. 
Then, the lead frame 1 is carried by the carrier 26, which is driven by the 
drive unit 27, along the carriage direction Y with a prescribed distance. 
The lead frame 1 is stopped at a prescribed position by the stopper 28 
which is located on an upper direction. At this time, cross-directional 
end portions of the lead frame 1 are held in the other guide spaces 24 
defined by the fixed upper rails 23a and 23b and the lower rail 21 so that 
the position of the lead frame 1 is settled in the shorter-side direction 
X, while the same is stopped by the stopper 28 so that its position is 
settled in the longitudinal direction. The lead frame 1 thus located in a 
prescribed position is then held by a transfer device (not shown) and the 
stopper 28 is downwardly driven by the drive unit 29, to release the lead 
frame 1 from the stopped state. After the lead frame 1 is transferred to a 
next fabrication step by the aforementioned transfer device, the stopper 
28 is upwardly moved to the original upper direction, while the carrier 26 
also returns to its original position. The aforementioned steps are so 
repeated as to carry and locate a plurality of lead frames. 
&lt;Problems of the Prior Art&gt; 
In the conventional apparatus 2, the lower rail 21 is fixed at a constant 
position, and the stopper 28 is moved along the carriage direction Y by a 
constant distance. In order to carry and locate lead frames 1 of various 
dimensions, therefore, it is necessary to prepare such apparatuses in 
response to the dimensions. In other words, the conventional apparatus 2 
is inferior in workability and economy for carriage and location of a 
plurality of types of lead frames 1. This problem is particularly serious 
in the field of the so-called multi-item small-quantity production for a 
number of types of lead frames 1 with small quantities. 
In the aforementioned apparatus 2, further, the upper rails 22a and 22b 
slide along the shorter-side direction X. If the lead frame 1 is so 
deformed that the end portions along the shorter-side direction X cannot 
be stored in the guide spaces 24, therefore, the upper rails 22a and 22b 
interfere with the deformed portion upon sliding toward the closed states, 
to damage the lead frame 1. 
SUMMARY OF THE INVENTION 
The present invention is directed to a method of carrying and locating a 
sheet frame for carrying a sheet frame, being substantially in the form of 
a flat plate, along a direction of a first axis in a major surface of the 
sheet frame by a prescribed distance and holding the same at a prescribed 
position. 
According to the present invention, the method of carrying and locating a 
sheet frame comprises (a) a guiding step of supporting the sheet frame to 
be slidable along the direction of the first axis, (b) a width adjusting 
step of adjusting a position for supporting the sheet frame in the step 
(a) in a direction of a second axis, being perpendicular to the first 
axis, in the major surface in correspondence to a first width of the sheet 
frame in the direction of the second axis, (c) a carrying step of carrying 
the sheet frame in the direction of the first axis by a prescribed 
distance in correspondence to a second width of the sheet frame in the 
direction of the first axis, and (d) a stopping step of stopping the sheet 
frame at a prescribed position in correspondence to the second width. 
According to the present invention, the position for slidably supporting 
the sheet frame can be adjusted while the distance and the position for 
carrying and stopping the sheet frame can also be adjusted respectively, 
whereby it is possible to arbitrarily carry and locate sheet frames having 
various sizes. 
Preferably, the guiding step (a) comprises (a-1) a step of guiding a first 
major surface of the sheet frame at an end portion of the sheet frame 
being provided along the direction of the second axis or in the vicinity 
of the end portion in the direction of the first axis, (a-2) a step of 
guiding a second major surface of the sheet frame at the end portion or in 
the vicinity of the end portion in the direction of the first axis, and 
(a-3) a step of guiding an edge surface of the sheet frame at the end 
portion in the direction of the first axis. 
According to the present invention, end portions of the sheet frame or 
portions close thereto are supported to be guided in carriage. Also when 
the sheet frame is formed by a lead frame having a resin-molded 
semiconductor device in the vicinity of its center, for example, it is 
possible to guide the sheet frame. 
Preferably, the step (a-1) comprises (a-1-1) a step of preparing (a-1-1-1) 
first means for guiding the first major surface of the sheet frame at the 
end portion or in the vicinity of the end portion in the direction of the 
first axis, and (a-1-1-2) second means provided adjacently to the first 
means (a-1-1-1) in the direction of the first axis for guiding the first 
major surface of the sheet frame at the end portion or in the vicinity of 
the end portion in the direction of the first axis, (a-1-2) a step of 
approaching the first means (a-1-1-1) to the first major surface from a 
substantially opposite direction, (a-1-3) a step of guiding the first 
major surface of the sheet frame in the direction of the first axis 
through the first means (a-1-1-1), and (a-1-4) a step of guiding the first 
major surface of the sheet frame in the direction of the first axis 
through the second means (a-1-1-2). 
According to the present invention, the means for guiding the first major 
surface is first approached to the major surface from an opposite 
direction, thereby guiding the first major surface. Even if the sheet 
frame is so deformed that the same cannot be stored in the guide spaces, 
therefore, it is possible to carry and locate the sheet frame without 
damaging the same. 
The present invention is also directed to an apparatus for carrying and 
locating a sheet frame for carrying a sheet frame, being substantially in 
the form of a flat plate, in a direction of a first axis in a major 
surface of the sheet frame by a prescribed distance and holding the same 
at a prescribed position. 
According to the present invention, the apparatus for carrying and locating 
a sheet frame comprises (a) guide means for supporting the sheet frame to 
be slidable in the direction of the first axis, (b) width adjusting means 
for adjusting a position for supporting the sheet frame by the means (a) 
in a direction of a second axis, being perpendicular to the first axis, in 
the major surface in correspondence to a first width of the sheet frame in 
the direction of the second axis, (c) carrier means for carrying the sheet 
frame in the direction of the first axis by a prescribed distance in 
correspondence to a second width of the sheet frame in the direction of 
the first axis, and (d) stop means for stopping the sheet frame at a 
prescribed position in correspondence to the second width. 
Accordingly, an object of the present invention is to provide a method and 
an apparatus for carrying and locating a sheet frame which can carry and 
locate sheet frames such as lead frames having a plurality of types of 
dimensions. 
A second object of the present invention is to provide a method and an 
apparatus for carrying and locating a sheet frame which can carry and 
locate a sheet frame without damaging the same even if the sheet frame is 
so deformed that the same cannot be stored in guide spaces.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
&lt;Preferred Embodiment 1&gt; 
&lt;Overall Structure of Apparatus 100 and System 800&gt; 
FIG. 1 is a general perspective view showing an apparatus 100 for carrying 
and locating a sheet frame according to an embodiment of the present 
invention. This apparatus 100 comprises a base 200, a guide rail (guide 
means) 300, a width adjusting device (width adjusting means) 400 for 
adjusting the width of the guide rail 300, a stop device (stop means) 500 
for stopping a lead frame 1 at various positions, and a carrier device 600 
(carrier means) for carrying the lead frame 1 with various carriage 
distances. The apparatus 100 serving as a principal part, together with a 
control unit 700, forms a system 800 for carrying and locating a sheet 
frame. &lt;Structure of Guide Rail 300&gt; 
FIG. 2 is a partial front elevational view of the apparatus 100, showing 
the structures of the guide rail 300 and the width adjusting device 400 in 
particular. FIG. 3 is an exploded perspective view showing a principal 
part of the guide rail 300. The structure of the guide rail 300 is now 
described with reference to FIGS. 1 to 3. 
The guide rail 300 comprises a pair of lower guide rails 301a and 301b for 
receiving the lead frame 1, in which a semiconductor device 1a is 
integrated, and guiding the same. The lead frame 1 is in the form of a 
substantially rectangular flat plate having a major surface (first major 
surface) 1b and another major surface (second major surface) 1c. The lower 
guide rails 301a and 301b slidably guide portions of the major surface 1c 
in the vicinity of end portions 1d of the lead frame 1 along a 
shorter-side direction X (direction of a second axis) on upper surfaces 
thereof. Two pairs of holders 302a and 302b are fixedly coupled to the 
lower guide rails 301a and 301b respectively. The holders 302a and 302b 
are supported slidably along the horizontal direction X by a guide rail 
303 which is fixed to the upper surface of the base 200. These guide rails 
301a and 301b are provided on upper surfaces thereof with two pairs of 
inclined projections 304a and 304b. Spaces between the pairs of the 
inclined projections 304a and 304b are broadened toward upper portions. 
These inclined projections 304a and 304b guide the lead frame 1 to a 
prescribed position on the lower guide rails 301a and 301b in a process of 
supplying the same. 
The guide rail 300 further comprises a pair of upper guide rails 310a and 
310b, which are rotatably supported by the lower guide rails 301a and 301b 
through rotation supporting points 311a and 311b. A pair of drive units 
312a and 312b are fixedly mounted on the upper surfaces of the holders 
302a and 302b, to drive transmitters 313a and 313b having grooves in the 
shorter-side direction X. The grooves of the transmitters 313a and 313b 
receive rollers 314a and 314b, which are rotatably mounted one portions of 
the upper guide rails 310a and 310b close to lower ends thereof, with 
small clearances. When the transmitters 313a and 313b are driven by the 
drive units 312a and 312b in the shorter-side direction X, the upper guide 
rails 310a and 310b are rotated about the rotation supporting points 311a 
and 311b. 
When the upper guide rails 310a and 310b enter closed states, i.e., when 
forward end portions 310c and 310d of the upper guide rails 310a and 310b 
are most approached to the upper end surfaces of the lower guide rails 
301a and 301b, guide spaces 30 are defined between the forward end 
portions 310c and 310d and the upper end portions of the lower guide rails 
301a and 301b. At this time, the upper guide rails 310a and 310b slidably 
guide edge surfaces 1e at the end portions 1d of the lead frame 1 and 
portions of the major surface 1b close to the end portions 1d. The guide 
spaces 30 store the end portions 1d of the lead frame 1 while leaving 
certain degrees of clearances. Thus, the lead frame 1 is supported at a 
prescribed position in the shorter-side direction X, while the same is 
slidable in a carriage direction Y, which is the longitudinal direction 
(direction of a first axis) of the lead frame 1, along the lower guide 
rails 301a and 301b and the upper guide rails 310a and 310b. 
The upper guide rails 310a and 310b are rotated between open states, in 
which the forward end portions 310c and 310d are most separated from the 
lower guide rails 301a and 301b, and the aforementioned closed states. 
The lower guide rails 301a and 301b are provided on the upper surfaces 
thereof with upper fixed guide rails 315a and 315b (FIG. 1) adjacently to 
the upper guide rails 310a and 310b. FIG. 4 is a front sectional view 
showing the lower guide rail 301a and the upper fixed guide rail 315a 
which is provided on its upper surface. Defined between the upper fixed 
guide rail 315a and the lower guide rail 301a is a guide space 30a, which 
is identical in shape to the guide spaces 30 defined between the upper 
guide rails 310a and 310b and the lower guide rails 301a and 301b. This 
also applies to the upper fixed guide rail 315b and the lower guide rail 
301b. Thus, the lead frame 1, whose end portions 1d are stored in the 
guide spaces 30, is smoothly moved into the guide spaces 30a of the same 
shapes in the process of carriage. Due to the guide spaces 30a, the lead 
frame 1 can slide in the carriage direction Y along the lower guide rails 
301a and 301b and the upper fixed guide rails 315a and 315b while 
maintaining the prescribed position along the shorter-side direction X. 
The lower guide rails 301a and 301b, the upper guide rails 310a and 310b 
and the upper fixed guide rails 315a and 315b support the end portions 1d 
of the lead frame 1 in the aforementioned manner. Thus, it is possible to 
support the lead frame 1 which is provided with the semiconductor device 
1a in a portion close to its center. 
The base 200 is provided on its upper surface with a pair of rail drive 
devices 316a and 316b, which drive the lower guide rails 301a and 301b to 
move the same along the shorter-side direction X. 
&lt;Structure of Width Adjusting Device 400&gt; 
FIG. 5 is a perspective view showing the width adjusting device 400. The 
structure of this width adjusting device 400 is now described with 
reference to FIGS. 1, 2 and 5. The width adjusting device 400 is adapted 
to adjust the width of the guide rail 300, i.e., the space between the 
pair of opposite lower guide rails 301a and 301b in response to the width 
(first width) of the lead frame 1 along the shorter-side direction X. The 
width of the guide rail 300 corresponds to the position for supporting the 
lead frame 1. 
The width adjusting device 400 comprises cams (polyhedral blocks) 401a and 
401b. Each of the cams 401a and 401b is formed by fixedly superposing two 
types of columns having bottom surfaces defined by two-dimensional figures 
which are point-symmetrical about symmetry axes in two stages so that the 
symmetry axes are matched with each other. Each column has a plurality of 
diameters which are varied with directions. 
The width adjusting device 400 further comprises a motor 402, rotation of 
which is transmitted to the cam 401a through a coupling 403 and a drive 
shaft 404. The drive shaft 404 is fixedly mounted on the cam 401a along 
the symmetry axis of the cam 401a. On the other hand, a driven shaft 405 
is fixedly mounted on the cam 401b along the symmetry axis thereof. The 
drive shaft 404 is rotatably and vertically fixedly supported by a holder 
406, thereby maintaining the cam 401a in a constant position along the 
vertical direction. Similarly, the driven shaft 405 is rotatably and 
vertically fixedly supported by another holder 407, thereby maintaining 
the cam 401b in a constant position along the vertical direction. Pulleys 
408a and 408b are fixedly mounted on the drive shaft 404 and the driven 
shaft 405 respectively, and a transmission belt 409 is extended along the 
pulleys 408a and 408b. The rotation of the motor 402 is also transmitted 
to the cam 401b successively through the drive shaft 404, the pulleys 
408a, the transmission belt 409, the pulley 408b and the driven shaft 405, 
whereby the two cams 401a and 401b are synchronously rotated while keeping 
the same rotational position. 
It is possible to vary the interspace between the pair of lower guide rails 
301a and 301b holding the cams 401a and 401b therebetween, by changing the 
rotational and vertical positions of the cams 401a and 401b. 
A discoidal detector 410 having marks on portions close to its outer edge 
is fixedly mounted on the drive shaft 404, while a rotation detector 411 
such as a rotary encoder is provided on the holder 406. The rotation 
detector 411 reads the marks provided on the detector 410, thereby 
detecting the positions of the cams 401a and 401b along the rotational 
directions. 
A block 412 mounted on the bottom surface of the base 200 is provided with 
a drive unit 413 for vertically driving the holder 406 and a position 
detector 413a for detecting the vertical position of the holder 406. The 
position detector 413a is formed by a reed switch, for example. The 
vertical movement of the holder 406 is guided by two guiders 414, which 
are fixedly mounted on the bottom surface of the base 200 for slidably 
supporting the holder 406. 
&lt;Structure of Stop Device 500&gt; 
FIG. 6 is a perspective view of the stop device 500. The structure of this 
stop device 500 is now described with reference to FIGS. 1 and 6. The stop 
device 500 is adapted to stop the lead frame 1 at a prescribed position 
along the carriage direction Y in response to a longitudinal width (second 
width) of the lead frame 1. 
The stop device 500 comprises a stopper 501, which is brought into contact 
with the edge of the lead frame 1 along the carriage direction Y for 
stopping the lead frame 1. This stopper 501 is fixedly mounted on an end 
of a mounting arm 502, while a roller 502a is rotatably mounted on another 
end of the mounting arm 502. A guide rod 503 supports the mounting arm 502 
slidably along the carriage direction Y and an opposite direction Ya, 
while fixedly supporting the same in a rotational direction about an axis 
of a shaft 503. Namely, the mounting arm 502 is integrally rotated with 
the shaft 503 following its rotation, while freely sliding along the axis 
of the shaft 503. The stopper 501 is upwardly or downwardly moved 
following such rotation of the mounting arm 502. 
A movable block 504 having a groove for receiving the roller 502 with a 
small clearance is fitted with and supported by a screw shaft 505 having a 
male screw, to be moved in the carriage direction Y or the opposite 
direction Ya following rotation of the screw shaft 505. Upon such movement 
of the movable block 504, the mounting arm 502 is guided by the shaft 503 
for similar movement. Due to the small clearance defined between the 
roller 502a and the movable block 504, the roller 502a rolls on the groove 
surface of the movable block 504 upon rotation of the mounting arm 502, 
whereby the rotation of the mounting arm 502 is not hindered by the 
movable block 504. Rotation of a motor 508 is transmitted to the screw 
shaft 505 through pulleys 506a and 506b and a transmission belt 507. 
An arm 509 is fixedly provided on an end of the shaft 503, while a roller 
509a is rotatably mounted on the forward end of the arm 509. A 
transmission block 510 having a groove for receiving the roller 509a with 
a small clearance is connected to a drive unit 511 through a rod 510a, to 
be moved in the shorter-side direction X by action of the drive unit 511. 
The rod 510a is slidably supported by a guide block 510b which guides the 
movement of the transmission block 510 in the shorter-side direction X. 
A substrate 512, which is a support for the overall stop device 500, is 
fixedly provided on the upper surface of the base 200. The substrate 512 
is vertically fixedly provided with plate type support plates 512a and 
512b, which rotatably support the shaft 503 and the screw shaft 505. The 
motor 508 is fixedly provided on the support plate 512a. The drive unit 
511 and the guide block 510b are fixedly supported by the upper surface of 
the substrate 512. 
&lt;Structure of Carrier Device 600&gt; 
FIG. 7 is a partial front elevational view of the apparatus 100. The 
structure of the carrier device 600 is now described with reference to 
FIGS.1 and 7. The carrier device 600 is adapted to carry the lead frame 1, 
which is held in the guide spaces 30 and 30a of the guide rail 300, in the 
carriage direction Y with a prescribed distance corresponding to the 
longitudinal width of the lead frame 1. 
The carrier device 600 comprises a carrier 601 for urging the lead frame 1 
in the carriage direction Y. This carrier 601 has a movable block 601a 
which is fitted with a screw shaft 602 having a male screw, and an arm 
601b which is fixedly connected to the movable block 601a so that its 
forward end portion comes into contact with the lead frame 1 to press the 
same. The screw shaft 602 is rotatably supported by support plates 602a 
and 602b which are uprightly provided on the base 200. A guide shaft 603 
is extended across the support plates 602a and 602b in parallel with the 
screw shaft 602, to slidably support the movable block 601a. Upon rotation 
of the screw shaft 602, therefore, the carrier 601 is translated in the 
carriage direction Y or the opposite direction Ya while keeping a constant 
condition with no rotation. A driven pulley 604a is mounted on an end of 
the screw shaft 602, so that rotation of a carriage drive motor 605 
provided on the base 200 is transmitted to the screw shaft 602 through a 
drive pulley 604b, a belt 606 and the driven pulley 604a. 
FIG. 1 illustrates the screw shaft 602 and the guide shaft 603 in a 
partially fragmented manner, for the convenience of illustration. 
&lt;Operation of Apparatus 100 and System 800&gt; 
The apparatus 100 and the system 800 operate along the following steps: The 
control unit 700 (FIG. 1), which is formed by a circuit containing a 
microcomputer and a storage circuit, stores information as to the objects 
of production (production information) including; information as to widths 
of the lead frame 1 along the longitudinal and shorter-side directions. 
&lt;First Step&gt; 
First, the control unit 700 transmits prescribed signals to the rail drive 
devices 316a and 316b. On the basis of these signals, the rail drive 
devices 316a and 316b move the pair of lower guide rails 301a and 301b to 
separate the same from each other, thereby sufficiently broadening the 
interspace therebetween. 
&lt;Second Step&gt; 
Then, the control unit 700 by way of a control means 700a calculates a 
space between the pair of upper guide rails 310a and 310b corresponding to 
the width of the lead frame 1 along the shorter-side direction X, and 
transmits a control signal corresponding to the as-calculated value to the 
motor 402 and the drive unit 413. In response to the signal, the motor 402 
and the drive unit 413 operate to set vertical and rotational positions of 
the cams 401a and 401b. The rotation detector 411 and the position 
detector 413a detect whether or not the cams 401a and 401b are set at 
prescribed positions, and feed back detection signals to the control unit 
700. The control unit 700 transmits control signals to the motor 402 and 
the drive unit 413 so that the detection signals are matched with signals 
corresponding to the prescribed positions. 
&lt;Third Step&gt; 
Then, the control unit 700 transmits prescribed control signals to the rail 
drive devices 316a and 316b. The rail drive devices 316a and 316b 
responsively operate to approach the pair of lower guide rails 301a and 
301b to each other, for pressing opposite vertical surfaces thereof 
against outer peripheral surfaces of the cams 401a and 401b. 
Thus, the interspace between the pair of lower guide rails 301a and 301b is 
set at a value corresponding to the width of the lead frame 1 along the 
shorter-side direction X. FIG. 8 is a partial front elevational view 
showing the guide rail 300, for typically illustrating the lower guide 
rail 301b whose vertical surface is pressed against the upper peripheral 
surface of upper stages of the cams 401a and 401b, for example. 
&lt;Fourth Step&gt; 
Then, the control unit 700 by way of a control means 700b calculates a 
carriage distance on the basis of the information as to the longitudinal 
width of the lead frame 1, and further calculates a stop position by way 
of a control means 700c of the lead frame 1 corresponding thereto, and 
transmits a control signal corresponding to the as-calculated stop 
position to the motor 508 (FIG. 1). In response to this control signal, 
the motor 508 is rotated in a prescribed direction by a prescribed amount. 
Following this rotation, the movable block 504 (FIG. 6) is moved by a 
prescribed distance, to set the stopper 501 at the stop position. The 
stopper 501 is vertically maintained at an upper position. 
&lt;Fifth Step&gt; 
Then, the control unit 700 (FIG. 1) transmits prescribed signals to the 
drive units 312a and 312b. On the basis of these control signals, the 
drive units 312a and 312b urge the transmitters 313a and 313b. As the 
result, the upper guide rails 310a and 310b are rotated about the rotation 
supporting points 311a and 311b, to enter open states. 
&lt;Sixth Step&gt; 
When the apparatus 100 is in this state, a supply unit SP (FIG. 2) such as 
a robot, which is prepared in the exterior of the apparatus 100, is 
employed to drop the lead frame 1 from above the lower guide rails 301a 
and 301b in a substantially horizontal condition, thereby mounting the 
same on the upper surfaces of the lower guide rails 301a and 301b. During 
the process of such dropping, the lead frame 51 is guided by the inclined 
projection 304a and 304b to be mounted on a prescribed position on the 
upper surfaces of the lower guide rails 301a and 301b. 
&lt;Seventh Step&gt; 
Then, the control unit 700 transmits prescribed signals to the drive units 
312a and 312b, which in turn draw the transmitters 313a and 313b in 
response to the control signals. Consequently, the upper guide rails 310a 
and 310b are rotated about the rotation supporting points 311a and 311b, 
to enter closed states. Thus, the lead frame 1 is held at a prescribed 
position along the shorter-side direction X, while being slidable along 
the lower guide rails 301a and 301b and the upper guide rails 310a and 
310b. 
&lt;Eighth Step&gt; 
Then, the control unit 700 (FIG. 1) transmits a control signal 
corresponding to the previously calculated carriage distance to the 
carriage drive motor 605, which is responsively rotated in a prescribed 
direction by a prescribed amount. Following such rotation, the carrier 601 
is moved in the carriage direction Y by a prescribed distance. At this 
time, the lead frame 1 is guided by the adjacent guide spaces 30 and urged 
by the forward end portion of the arm 601b, to be carried in the carriage 
direction Y by a prescribed distance. Such carriage is ended at a position 
where the edge surface of the lead frame 1 along the carriage direction Y 
is substantially in contact with the stopper 501. At this time, the both 
ends 1d of the lead frame 1 along the shorter-side direction X are 
separated from the guide spaces 30 and stored in the adjacent guide spaces 
30a. In this state, the lead frame 1 is constrained by the upper fixed 
guide rails 315a and 315b in the shorter-side direction X with a 
prescribed clearance, by the lower guide rails 301a and 301b and the upper 
fixed guide rails 315a and 315b in the vertical direction with a 
prescribed clearance, and by the stopper 501 and the carrier 601 in the 
longitudinal direction. Thus, the lead frame 1 is held in a state being 
located at a prescribed position. 
FIG. 9 is a partial plan view showing the lead frame 1 being in this state 
and the upper fixed guide rails 315a and 315b supporting the same. The 
upper fixed guide rails 315a and 315b are provided with slits 317a and 
317b having certain lengths from ends in the carriage direction Y. Holes 
If are provided at prescribed intervals in the vicinity of both edges of 
the lead frame 1 along the shorter-side direction X. These holes If are 
partially exposed from the upper fixed guide rails 315a and 315b in the 
vicinity of end portions of the lead frame 1 along the carriage direction 
Y. 
&lt;Ninth Step&gt; 
Then, a transfer device (not shown) provided in an apparatus for carrying 
out a step of forming the lead frame 1 is moved to a prescribed position, 
so that projections (not shown) provided in the transfer device engage 
with the exposed holes 1f. 
&lt;Tenth Step&gt; 
Thereafter the control unit 700 (FIG. 1) transmits a prescribed control 
signal to the drive unit 511 (FIG. 6), which in turn is rotated in a 
prescribed direction in response to the control signal, whereby the 
stopper 501 is downwardly moved to release the lead frame 1 from the 
stopped state. Then the aforementioned transfer device is moved in the 
carriage direction Y, so that the lead frame 1 is separated from the guide 
rail 300 and transferred to the following forming step. 
&lt;Eleventh Step&gt; 
When the lead frame 1 is carried to the exterior of the guide rail 300, the 
control unit 700 transmits a prescribed control signal to the drive unit 
511. The drive unit 511 is rotated in a prescribed direction in response 
to the control signal, whereby the stopper 501 is upwardly moved to return 
to a position capable of stopping a new lead frame 1. 
&lt;Twelfth Step&gt; 
Then, the control unit 700 transmits a prescribed control signal to the 
carriage drive motor 605 (FIG. 1 and FIG. 7), which in turn is rotated in 
a prescribed direction by a prescribed amount in response to the control 
signal. Thus, the carrier 601 returns to the prescribed position in 
advance of the next carriage. 
&lt;Thirteenth Step&gt; 
When a subsequently supplied lead frame 1 is of the same type as the lead 
frame 1 which has been carried and located, the aforementioned fourth to 
twelfth steps are repeated. If the subsequently supplied lead frame 1 is 
different from the preceding lead frame 1, on the other hand, the first to 
twelfth steps are repeated. 
&lt;Advantages of Apparatus 100 and System 800&gt; 
In the apparatus 100 and the system 800 according to this preferred 
embodiment, the interspace between the pair of lower guide rails 301a and 
301b is variable, whereby it is possible to handle various lead frames 
having different widths in shorter-side directions. Further, the position 
of the stopper 501 and the distance of carriage by the carrier 601 are 
variable, whereby it is possible to handle various lead frames 1 having 
different widths in longitudinal directions. When the apparatus according 
to this preferred embodiment is employed, it is possible to handle various 
lead frames 1 having dimensions which are generally different in 
shorter-side and longitudinal directions. 
Further, the guide rail 300 has a mechanism for opening and closing the 
upper guide rails 310a and 310b, which are approached to each other along 
a direction substantially perpendicular to the surface of the lead frame 1 
for suppressing the end portions 1d thereof. Even if the lead frame 1 is 
so deformed that the same cannot be stored in the guide spaces 30, 
therefore, it is possible to store the end portions 1d of the lead frame 1 
in the guide spaces 30 without damaging the same. 
&lt;Preferred Embodiment 2&gt; 
The upper fixed guide rails 315a and 315b maybe provided with pressers for 
pressing the lead frame 1 with proper pressures. FIG. 10 is a partial side 
sectional view showing an apparatus according to a second preferred 
embodiment of the present invention, and FIG. 11 is a partial front 
sectional view showing the same. Pressers 90 are mounted on upper fixed 
guide rails 315a and 315b by screws 91. Such pressers 90 are obtained by 
bending plates of phosphor bronze, for example, having excellent 
elasticity. The upper fixed guide rails 315a and 315b are provided with 
holes 92, so that the pressers 90 pass through the holes 92 to be in 
contact with the upper surfaces of the lower guide rails 301a and 301b 
while applying pressures of suitable strength. When a lead frame 1 is 
carried under the upper fixed guide rails 315a and 315b, therefore, the 
lead frame 1 is located under the pressers 90 (FIG. 10). Consequently, the 
pressers 90 apply proper pressures to the lead frame 1 to cause proper 
frictional force, thereby holding the lead frame 1 in a stable position 
even if constraining means such as a carrier 601 is released. 
In the apparatus according to the second preferred embodiment, therefore, 
it is possible to carry out the twelfth step immediately after completion 
of the aforementioned eighth step. Thus, it is possible to carry out the 
twelfth step to the seventh step after repetition simultaneously with the 
ninth to eleventh steps in a parallel manner. In the apparatus according 
to this preferred embodiment, therefore, it is possible to execute the 
processing with higher working efficiency as compared with the prior art. 
&lt;Preferred Embodiment 3&gt; 
The cams 401a and 401b, which are obtained by stacking polyhedrons in two 
stages as shown in FIG. 5, may be replaced by those of a single-stage 
structure, or each of such cams may be obtained by stacking polyhedrons in 
three or more stages, as illustrated in FIG. 12 showing a partial front 
elevational view of a guide rail 300. The structure of the cams may be 
selected from the above in response to necessity in manufacturing steps. 
&lt;Preferred Embodiment 4&gt; 
In the apparatus according to the aforementioned first preferred 
embodiment, the upper guide rails 310a and 310b are rotated about the 
rotation supporting points 311a and 311b. However, the upper guide rails 
310a and 310b may be in other structure, so far as the same are downwardly 
moved from portions substantially vertically above the lead frame 1 to 
hold the edges of the lead frame 1. For example, the upper guide rails 
310a and 310b may be approached to the edges of the lead frame 1 from 
vertical directions or oblique directions close to the vertical 
directions. Also in this structure, it is possible to store the edges of 
the lead frame 1 in the guide spaces 30 without damaging the same even if 
the lead frame 1 is so deformed that the same cannot be stored in the 
guide spaces 30, similarly to the first preferred embodiment. 
While the invention has been shown and described in detail, the foregoing 
description is in all aspects illustrative and not restrictive. It is 
therefore understood that numerous modifications and variations can be 
devised without departing from the scope of the invention.