JPH043105B2 - - Google Patents

Description

[Detailed Description of the Invention] (a) Industrial Application Field The present invention relates to a mechanism for checking the number and positioning of lead frames to detect whether or not lead frames to be molded are mounted in proper positions in a mold. .

(b) Prior art Conventionally, in a fully automatic molding machine in which semiconductor elements having structures such as ICs and transistors are die-bonded and wire-bonded, appropriate resin is molded onto the lead frame. A mold having a fittable positioning pin is not equipped with a mechanism for detecting whether or not the lead frame is mounted at a proper position on the mold when the lead frame is mounted on the mold. Therefore, if the lead frame is not in the correct position in the mold, or if more than the specified number of lead frames are attached, the device operates regardless of this, and the above-mentioned malfunction cannot be detected until after the molding is completed. .

Therefore, it may be possible to equip the mold into which the lead frame is mounted with a heat-resistant proximity sensor or the like separately from the above device to prevent problems such as misalignment of the lead frame or mounting more than the specified number of lead frames. Then, in order to arrange the proximity sensor for each lead frame set in the mold, it is necessary to perform some processing on the mold.

(c) Purpose This invention uses positioning pins provided on the mold (lower mold) to accurately check whether there is any misalignment of lead frames mounted on the mold (lower mold) or the specified number of lead frames. The purpose of this invention is to provide a mechanism for checking the number and positioning of lead frames.

(D) Structure The lead frame number and positioning check mechanism according to the present invention is a lead frame number and position check mechanism for a frame loader that attaches the lead frames to positioning pins provided in a mold, and is a mechanism for checking the number and positioning of lead frames in a frame loader that attaches the lead frames to positioning pins provided in a mold. A checker pin having a hole into which the positioning pin is inserted is provided in the formed tip, a drive means for moving the checker pin up and down, and a detection means for detecting the positional deviation and number of lead frames by lowering the checker pin. It is a feature.

(e) Embodiment FIG. 1 is a perspective view showing an embodiment of a mechanism for checking the number and positioning of lead frames according to the present invention.

In the figure, 1a is a base of a mold, and a lower mold 2 in which a plurality of cavities 3 are formed is disposed on the upper surface of the base. Positioning pins 4 are erected on the upper surface of the lower mold 2 so as to correspond to positioning holes 6 formed at both ends of the lead frame 5 in the longitudinal direction. In this embodiment, this mold is for four frames, and the positioning pin 4 thereof has a conical shape.

Reference numeral 1b denotes a base disposed above the base 1a, and an upper mold (not shown) is disposed on the lower surface of the base in correspondence with the lower mold 2.

7 is a frame loader equipped with a check mechanism for mounting the lead frame 5 in a predetermined position on the lower mold 2 and a mold frame check mechanism (hereinafter simply referred to as the check mechanism) for detecting the presence or absence of positional deviation of the lead frame 5. , is configured to move parallel to the lower mold 2 at a predetermined distance as shown by the arrow in FIG. Specifically, it will be explained below with reference to FIGS. 2 to 4. FIG. 2 is a partially cutaway plan view schematically showing the structure of the frame loader 7, and FIG. 3 is a partially cutaway side view schematically showing the structure of the frame loader.
FIG. 4 is a partially cutaway front view schematically showing the structure of the frame loader. Furthermore, this frame loader 7
exemplifies a mold configured to correspond to a four-frame mold.

The frame loader 7 includes a top cover 71a attached to the top, a front wall 71b, and a side wall 71.
c, 71d and the base plate 7 located on the bottom surface.
1e and a box body 7 having approximately the same dimensions as the base 1a of the lower mold 2.
1 is constructed, and the side walls 71c, 71 of this box body 71
Slide shafts 72a, 72b are placed outwardly at the top of d.
are fixed parallel to the side walls 71c and 71d. On the base plate 71e, a first air cylinder 8 as a driving means for moving it up and down, check mechanisms 9a, 9b and 9c, 9 (not shown) are attached to the lower die 2 of the lead frame 5.
d, check mechanisms 10a and 10b for determining whether or not the lead frame 5 is fitted to the positioning pin 4 of the lower die 2, and 10c and 1 (not shown).
0d are respectively arranged at predetermined positions. Furthermore, the rod 82 of the first air cylinder 8 is fixed approximately at the center of a rod 73 constructed to connect the center positions of the side walls 71c and 71d.

The check mechanism 9a includes a rack 91 disposed in parallel with the rod 73 at a predetermined interval.
a, a plurality of pinion groups 93a that rotate with the movement of this rack 91a, and this pinion group 9.
3a, and a check portion 94a (see FIG. 3) that clamps and releases the lead frame 5 in conjunction with the check portion 94a. Note that the check mechanisms 9b, 9c, and 9d also have the same configuration as the check mechanism 9a, and the check mechanisms 9a, 9c, and 9b, 9d are arranged with the first air cylinder 8 in between.
are provided facing each other. And Ratsuku 9
One end of 1a and 91b is connected by a connecting plate 95, and a rod 11 of a second air cylinder 11 for driving the rack is located at the lower end of the connecting plate 95 in the center thereof.
1 is fixed (see Figure 4). Further, substantially L-shaped light shielding plates 13a and 13b are fixedly installed at the other ends of the racks 91a and 91b so as to face each other, and photointerrupters 14a and 14b that emit signals are operated by these light shielding plates 13a and 13b. It is fixed to the base plate 71e via brackets 141a and 141b. That is, the light shielding plate 13b of the rack 91b is the photointerrupter 14b.
When the chuck portions 94a, 94 are in a position that blocks the
b and 94c, 94d (not shown) are in the open state, and when the racks 91a, 91b are moved in the direction of arrow C in FIG. , 94d are set to be in a sandwiched state. Note that the open state means that the lead frame is not clamped.

The check mechanism 10a, which is the main part of the embodiment according to the present invention, is provided close to the front of the rack 91a, and is fixed to a mounting base 101a fixed to the base plate 71e and approximately at the upper center of the mounting base 101a. a third air cylinder 12a for driving the check mechanism; spring stoppers 102a, 103a vertically movable and erected inwardly at both ends of the mounting base 101a; and spring stoppers 102a, 103a. It is composed of checker pins 104a and 105a that fix the checker pins 104a and 105a, and an interlocking plate 106a that bridges the checker pins 104a and 105a in a slidable manner. Note that the tip portions 1 of the checker pins 104a and 105a
07a, 108a have flat tips, and a plurality of holes 404 into which the positioning pins 4 can be inserted with a predetermined accuracy are provided in the flat surface, as shown in FIG. Further, approximately L is provided at approximately the center of the spring stoppers 102a and 103a.
Photointerrupters 19a, 2 which emit signals by passing through the light shielding plates 17a, 18a are attached.
0a is fixed to the base plate 71e via brackets 191a and 201a. Note that the photointerrupters 19a, 20a and the light shielding plate 17
a and 18a constitute a detection means for detecting the positional deviation and number of lead frames.

Thus, the rod 121a of the third air cylinder 12a is fixed approximately below the center of the interlocking plate 106a. This third air cylinder 12a
The checker pins 104a and 105a are moved up and down in conjunction with the forward and backward movements of the rod 121a. Note that springs 15a and 16a are fitted between the interlocking plate 106a and the spring stoppers 102a and 103a, respectively. The check mechanisms 10b, 10c, and 10d are also constructed in the same manner as the check mechanism 10a, and the check mechanisms 10a, 10c and 10b, 10d are arranged opposite to each other on both sides of the check mechanisms 9a, 9c, and 9b, 9d, respectively. There is. Note that the driving means for driving the downward and upward movement of the checker pin is the third drive means.
Air cylinder 12a, springs 15a, 16
a, spring stoppers 102a and 103a, and an interlocking plate 106a.

For example, to explain the operation of the check mechanism 10a, first, the third cylinder 12a is operated to move the rod 121a downward to lower the checker pins 104a, 105a, and to move the checker pins 104a, 105a in conjunction with the checker pins 104a, 105a. The light shielding plates 17a and 18a are lowered. At this time, when the tip ends 107a, 108a of the checker pins 104a, 105a are lowered to the predetermined positions, as shown in FIG. The portion 107a presses the lead frame 5, and the light-shielding plates 17a and 18a block the photo-interrupters 19a and 20a, so a detection circuit (not shown) detects that the lead frame is at the correct position in the mold based on the signal from the photo-interrupter. do. FIG. 6 shows a case where there are a plurality of lead frames 5 (two in the illustrated example). As shown in the figure, when the positioning pin 4 is inserted, the tip portion 107a presses the circumferential surface of the positioning hole 51 of the lead frame 5, so that the number of sheets can be accurately detected.
Before the checker pins 104a, 105a reach the predetermined positions, they come into contact with some abnormal condition (for example, a misaligned lead frame or two lead frames overlapped) and descend by a predetermined amount, as shown in FIG. If not, the signal from the photointerrupters 19a and 20a will not be output, so a detection circuit (not shown) will detect an abnormal state of the lead frame, stop all work, raise the base plate 71e, and then move the frame loader. 7 in the direction of arrow B in FIG. 1, the operator is notified of the abnormality by, for example, flashing a warning light, and the operator repairs the lead frame.
Note that the checker pins 104a, 105a
The interlocking plate 106 is connected by springs 15a and 16a.
Since the space between the checker pin 1 and
This prevents the lead frame from being destroyed by 04a and 105a.

Next, the operation of the frame loader 7 described in detail above will be explained.

The rod 111 of the second air cylinder 11 is moved toward the side wall 71d, and in conjunction with this, the racks 91a and 91b are moved in the direction of arrow C in FIG. As a result, the pinion groups 93a, 93b and 93c, 93d (not shown) are rotated in a predetermined direction, and in conjunction with this, the chuck portions 94a, 94b are rotated.
94c and 94d (not shown) rotate to sandwich the lead frame 5 (dotted chain line in FIG. 3), and sandwich the lead frame placed at a predetermined position.

By moving the frame loader 7 in the direction of arrow A in FIG.
(see figure).

By driving the first air cylinder 8 and moving the cylinder body 81 downward, the base plate 71e is lowered to a predetermined position.

The rod 111 of the second air cylinder 11
By moving in the opposite direction to the above,
The racks 91a, 91b are moved in the direction of arrow D in FIG. 2, and the pinion groups 93a, 93b, 93c,
93d in a predetermined direction to attach the chuck part 94.
a, 94b, 94c, and 94d are opened and the lead frame is mounted on the lower die 2 (lead frame mounting step).

Third air cylinder 12a, 12b, 12
c, 12d, and the rods 121a, 121
By moving the checker pins 104a, 105 downward,
a, 104b, 105b, 104c, 105
c, 104d, and 105d are lowered.

If it is determined to be normal in the first
After raising the cylinder body 81 of the air cylinder 8 and raising the base plate 71e,
The frame loader 7 is returned in the direction of arrow B in FIG. 1, and the molding process begins.

If an abnormality is determined in , all operations are stopped as described above, the base plate 71e is raised, and then the frame loader 7 is returned in the direction of arrow B in FIG. 1 and stands by.

As explained in detail above, the fully automatic molding process machine is configured so that after the lead frame is mounted, the mounting position is immediately checked and the molding process proceeds to the next sequential molding process.

In addition, the base plate 71e, the rack 91a,
91b and checker pins 104a, 105a
The driving means such as the above are not limited to those described above, and the detection means are also the same.

Further, although the frame loader 7 is equipped with a mechanism for checking the number and positioning of lead frames as described above as an example, the present invention is not limited to this and may be formed individually. Of course.

(f) Effects According to the mechanism for checking the number and positioning of lead frames according to the present invention, it is possible to quickly and accurately check for misalignment of lead frames and check for the specified number of lead frames, thereby preventing mold misalignment during the resin sealing process. etc. can be prevented. That is, it becomes possible to improve productivity and yield.

Furthermore, even if the mechanism for checking the number and positioning of lead frames is used, there is no need to process the mold as in the past, so it can be applied immediately to the mold currently in use. .

Further, in the case of the above-mentioned embodiment, there is an effect that the lead frame mounting and inspection work can be carried out more quickly than in the case where the lead frame is installed and inspected separately.

[Brief explanation of drawings]

FIG. 1 is a perspective view schematically showing an embodiment of the lead frame number and positioning check mechanism according to the present invention, FIG. 2 is a partially cutaway plan view schematically showing the structure of a frame loader 7, and FIG. 4 is a partially cutaway side view schematically showing the structure of the frame loader 7, and FIG. 4 is a partially cutaway front view schematically showing the structure of the frame loader 7. FIG. 5 to 7 are cross-sectional views showing the operation of the checker pin.
The figure shows one sheet in a normal state, FIG. 6 shows a case where a plurality of sheets are installed in the same state, and FIG. 7 shows an abnormal state. 2...Lower mold, 4...Positioning pin, 5...Lead frame, 6...Positioning hole, 10a...Check mechanism, 104a, 105a, 104b, 10
5b...Chetzka pin, 106a...Interlocking plate,
102a, 103... Spring stopper, 15
a, 16a...Spring, 12a...Third air cylinder, 121a...Rot, 17a, 18
a, 17b, 18b... light shielding plate, 19a, 20
a, 19b, 20b... photo interrupter.

Claims (1)

[Claims] 1. A checker pin that is a mechanism for checking the number and positioning of lead frames of a frame loader that attaches lead frames to positioning pins provided on a mold, and has a flat tip with a hole into which the positioning pin is inserted. A mechanism for checking the number and position of lead frames, comprising: a drive means for moving the checker pin up and down; and a detection means for detecting the positional deviation and number of lead frames by lowering the checker pin.