JP3535993B2 - Positioning device for small workpieces - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a positioning device for microscopic workpieces, and more particularly to a positioning device for electronic components such as semiconductor devices such as ICs and transistors and capacitors having a rectangular shape. Hereinafter, the semiconductor device, the capacitor, and the like are collectively referred to as a work, and the description will proceed.

[0002]

2. Description of the Related Art In a work, the whole of a small chip which is a circuit element is molded with resin, and its outer shape is generally quadrangular, and a plurality of pins serving as electrode terminals are provided on its side surface.
The manufacturing process after resin molding is the forming process that first bends and forms the pin that is straight to insert into the socket or the substrate, the measuring process that contacts the measuring probe to the pin and measures the characteristics of the circuit element, and There is a taping process and the like in which the final product is stored in an insertion pocket provided in a tape wound in a hoop shape.

The work is conveyed on a rotary table or a conveyor, is transferred to a processing mechanism portion of the above-described process adjacent to the work, and after being processed, the work is returned to the rotary table. However, if the work on the rotary table is simply transferred as it is, there is a problem in position accuracy, and it is necessary to reposition the work once and then transfer it. This is because the positioning accuracy of the work is not good on the rotary table. For example, in the measurement process, the pin of the work does not abut well on the measurement probe, and the measurement cannot be performed. This is because there is a problem that it will not fit inside.

Therefore, a work positioning mechanism is provided between the rotary table and the processing mechanism. The work is once transferred and positioned there, and then transferred to the processing mechanism section. A positioning device often used in the positioning mechanism will be described below with reference to FIG.

Although not shown in the figure, while the rotary table which is driven intermittently is stopped, the work 1 placed on the transport head of the rotary table is vacuum-sucked by the suction head 3 and the positioning claws 4a to 4d of the positioning device. Reprinted in. Although not shown in the figure, the suction head 3 is located at the tip of the arm of the pick and place unit, and the arm performs vertical movement operation and horizontal movement operation, and in some cases, rotation operation on a horizontal plane is also possible. Further, the suction head 3 has a suction hole whose work suction surface is an opening end, and the suction hole is connected to a vacuum generator via an air pipe or a solenoid valve, so that the work 1 can be vacuum-sucked or released. .

Next, as shown in FIG. 4, while holding the work 1 by the suction head 3, the positioning claws arranged on all sides are slid in the directions of the arrows to push the side surface of the work 1. As a result, the work 1 is positioned while sliding on the suction surface. The figure shows a state where the positioning claws 4a to 4d are all slid inward and the positioning of the work 1 is started. When the positioning is completed, the work 1 is transferred to a predetermined processing mechanism section and a predetermined processing is performed.

[0007]

However, when the work is positioned by using the above-mentioned positioning device, there are the following problems. For example, the outer shape is 3 mm × 1.
In the case of a work having a size of about 5 mm, generally, there is a maximum deviation of 0.4 mm in the XY directions on the rotary table. In addition, when transferring to a predetermined processing mechanism section, it is necessary to suppress the deviation within 0.1 mm. Therefore, when all the positioning claws are slid inward and closed, the play between the portion surrounded by the tips of the positioning claws and the work outline is
The distance is about 0.05 mm in the Y direction. Of course, if the backlash is set to 0 mm or less, the work will be damaged when the positioning claw is closed, so that cannot be done.

By the way, since a pin is formed on the side surface of the work, the tip of the positioning claw for pushing the side surface has a small width or an escape groove so as not to hit the pin. In FIG. 4, the positioning claws 4a and 4b hit it.
By the way, although pushing the side molded with resin,
Generally, the hardness of the resin is high, and the positioning frequency is very high, and the frequency is usually once or more / 0.5 seconds, which causes the pawl to wear in a short time. Therefore, in order to prevent wear as much as possible, cemented carbide is used for the nails, and quenching treatment is also applied.

However, if the operation frequency is high, the nails will be worn out after several months of use, and the nails will have to be replaced. Further, as described above, the work to be handled is very small. Also, since the thickness is thin, the nails are inevitably small, and the thickness must also be thin, which causes the nails to break,
Sometimes the tip was chipped and the nail had to be replaced in this case as well.

On the other hand, when the pawl is slid, the pawl is usually fixed to a linear slide unit composed of a linear guide or a cross roller guide to perform the sliding operation. For example, a compression spring is provided on one of the opposing pawls. A method in which the device is built-in and a pawl is pressed against the work by a spring to perform positioning is also considered. However, in this case, when the claws are closed, the tips of all four claws come into contact with the side surface of the work,
Higher positioning accuracy could be obtained, but when the claw is released after the positioning is completed, the phenomenon that the work is attracted to the claw occurs and the work that has been positioned carefully shifts again, so a spring is used for positioning. I couldn't do that.

Further problems in design and manufacturing will be described below.
Although not shown in the drawings, in order to slide the positioning claws, a linear slide unit such as the linear guide or cross roller guide described above, a cam for driving the slide unit, and a motor for rotating the cam are used. Minimum required. The cross roller guide is an expensive part, and the cam requires a lot of work for designing and assembling. Of course, control parts for driving the motor are also required. In other words, the conventional positioning device has a high manufacturing cost in terms of both constituent materials and design / assembly adjustment.

[0012]

In order to achieve the above object, the present invention uses the following means. A plurality of rotating rollers are arranged in a horizontal direction parallel to the respective side surfaces of the workpiece and the rotation axis, and the workpiece sucked by the suction head from above is vertically placed in the space surrounded by the plurality of rollers. The feature is that the work is positioned by inserting into and pulling out from.

Further, the plurality of rotating rollers have the same maximum outer diameter, the rotation axes are on the same plane, and a plurality of inner straight lines formed by intersecting the maximum outer peripheral portion of the rotating roller with the same plane. Each of the polygons extended and surrounded by the straight lines is similar to the work and larger than the work, and is also characterized in that an escape groove for avoiding a protruding portion on the side surface of the work is provided on the outer circumference of the rotating roller.

Further, a push-up rod vertically moving in the vertical direction is arranged in a space surrounded by a plurality of rotary rollers, and a stop point on the upper surface of the push-up rod is arranged with the rotary shafts of the plurality of rotary rollers. Above the same plane, the push-up bar descends by an external force applied downward from above, and also has a force that always pushes upward, and the force that the push-up rod pushes upward is applied to the compression spring. It is characterized by having been obtained.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of a positioning device according to the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a perspective view showing the outline of the present invention, FIG. 2 is a plan view thereof, and FIG. 3 is a side view of FIG. 1 seen from the direction of arrow A. Regarding the same as the conventional one,
The same reference numerals as in the conventional explanatory diagram are used.

First, the configuration will be mainly described with reference to FIGS. 1 and 2. First, four rotating rollers 10a to 10d are arranged. Although not shown, each of them has a built-in ball bearing and is rotatable. Although not shown, their roots are fixed to a part of the positioning device. Also, those rotating rollers 10a-
10d has the same maximum outer diameter, the rotation axes are on the same plane, and the two rotation rollers, for example, the rotation axes of 10a and 10c, which are arranged on the opposite side surfaces of the work 1, are parallel to each other. In addition, although the distances between them are not arranged to be in contact with each other, the maximum outer peripheral portions of the rotating rollers 10a to 10d respectively extend a plurality of inner straight lines intersecting the same plane, The rectangle surrounded by the straight lines is similar to the work 1 and larger than the work 1. The backlash of both sides is about 0.05 mm on one side surface side.

Further, an escape groove 11 is provided in each of the rotating rollers 10a and 10c. This is to prevent the pin 2 projecting from the side surface of the work 1 from hitting the rotation rollers 10a and 10c when the work 1 is inserted from above into the space surrounded by the rotation rollers. It should be noted that the rotary rollers 10b and 10d are not provided with the escape groove 11 because they are not necessary.

In addition to this, there is a push-up bar 12, which is arranged in the space surrounded by the rotating rollers 10a to 10d and moves vertically in the vertical direction. Further, the stop point on the upper side of the upper surface of the push-up rod 12 is set to be higher than the above-mentioned same plane on which the rotating shafts of the rotating rollers 10a to 10d are arranged.
Further, although not shown, the push-up bar 12 is always pushed upward from below by a compression spring.

Subsequently, the positioning process according to the present invention will be described mainly with reference to FIG. FIG. 3 shows an arrow A in FIG.
It is the side view seen from the direction, across (a)-(c),
The transition in which the work 1 is positioned is shown. For the sake of clarity, the rotary rollers 10a and 1a in FIG.
0b is omitted from the figure, and the rotary roller 10c is depicted by a hidden line in a portion hidden by the suction head 3 and the work 1.

Although not shown, the work 1 is adsorbed from the rotary table described above and moved above the positioning device (above the push-up rod 12). FIG. 1 shows the state at this time. At this time, generally, the work 1 is displaced by up to 0.4 mm in the X and Y directions, so it is necessary to perform positioning. Then, the suction head 3 descends as it is. In the middle of the process, first the lower surface of the work 1 comes into contact with the upper surface of the push-up rod 12,
The work 1 is lowered while being sandwiched between the suction head 3 and the push-up rod 12. Therefore, if the force for pushing up the push-up rod 12 is too strong, that is, if a compression spring with a large reaction force is used, the work 1 will be damaged when it comes into contact with the push-up rod 12, so consider not to make the spring force too strong. Must.

Next, the work 1 continues to descend while its side surface contacts the outer peripheral portion of the rotating roller, and stops at a position where the upper surface of the work 1 is below the rotation axis of the rotating roller. FIG. 3A shows this state. While the work 1 is descending, each side surface contacts the outer peripheral portion of the rotating roller, and the rotating roller rotates accordingly. The arrow drawn on the rotating roller 10d shows the state of this rotation. At this time, the work 1 slides on the XY plane while being sandwiched between the suction head 3 and the push-up rod 12. At the time of FIG. 3A, the work 1 enters the range of the quadrangle surrounded by the maximum outer peripheral portion of the rotating roller. In other words, the positioning is within ± 0.05 mm in the XY directions.

Of course, the rotating rollers 10a and 10c have pins 2
Since the escape groove 11 is provided, the work 1 can be positioned without breaking or damaging the pin 2 on the side surface of the work 1.
Here, if necessary, the suction force may be turned off or weakened when the suction head is lowered. Then, the frictional force between the upper surface of the work 1 and the lower surface of the suction head 3 can be reduced, the work 1 can be easily positioned, and the occurrence of scratches or the like due to the friction between the two can be prevented. At the same time, from the same viewpoint, regarding the shape of the upper surface of the push-up rod 12,
It is preferable that the push-up rod 12 stably supports the work 1 from below and has a small frictional force, and one example is one in which round pins with rounded tips stand at four corners.

Next, the suction head 3 starts rising as it is. At this time, the work 1 is sandwiched between the suction head 3 and the push-up rod 12 and rises, as in the case of lowering. Figure 3 (b)
Represents the ascending process. In the process from (a) to (b), the positioned work 1 passes through the maximum outer shape of the rotary roller again, and at that time, the side surface of the work 1 may slightly contact the rotary roller. Therefore, the workpiece 1 that has already been positioned will not be displaced.

Now, if there is no push-up rod 12 and the work 1 is not supported from below, the suction head 3
However, there is a possibility that the work 1 may drop when it comes into contact with the rotating roller when passing through. However, if the push-up bar 12 is provided, this problem will not occur. The push-up bar 12 lifts the work 1 while preventing the work 1 from falling, and is a so-called knockout mechanism of the work 1.

After that, the suction head 3 continues to move upward. When the push-up rod 12 reaches the upper stop point, the push-up rod 12 stops without further raising, and the work 1 naturally separates from the push-up rod 12 in the process of raising the suction head 3. FIG. 3C illustrates the situation at that time. After that, the suction head 3 moves up and down or horizontally while sucking the work 1, and is transferred to the next predetermined treatment mechanism section such as measurement or taping.

Referring to the rotating roller, the rotating roller contacts the work when the work is positioned, but the rotating roller then rotates. Therefore, even if the workpieces come into contact with each other, they do not continuously rub against the same surface of the rotating roller, and therefore the rotating roller is hardly worn. Therefore, it is not necessary to use the material that is the super hard material used for the conventional positioning claws, and ordinary iron may be used.

In the above description of the invention,
In the explanatory diagram in the middle, the side surfaces on which the workpiece is positioned are all drawn in the vertical direction, that is, parallel to the direction in which the suction head moves up and down, but this is not necessarily the vertical direction. It may be tapered in the vertical direction. Anyway, the work can be positioned by arranging the rotary roller on the basis of the maximum outer shape of the work when the work is viewed from above.

Finally, in the above description, a rectangular electronic component has been targeted for positioning. However, considering the arrangement of the rotating roller, this is not limited to a rectangular shape, but a triangular or pentagonal or more polygonal workpiece can be obtained. Can also be applied. Of course, in addition to this, the present invention is not limited to electronic parts, but can be applied to other polygonal objects.

[0029]

As described above, the positioning device of the present invention has a structure in which a plurality of rotating rollers and a push-up bar are arranged in a space surrounded by them.
Positioning can be performed simply by passing the work adsorbed by the suction head downward into the space and pulling up again. Further, the rotating roller does not require any motor or other driving device, and has a very simple structure in which a ball bearing is incorporated.
As for the push-up rod, only the compression spring needs to be built therein, and the structure is also simple. Therefore, there are no expensive parts, and a drive source such as electricity or high-pressure air is not required, so that no design relating to them is required, and the manufacturing cost can be significantly reduced. At the same time, the positioning device as a whole can be downsized.

[Brief description of drawings]

FIG. 1 is a perspective view showing an outline of a positioning device of the present invention.

FIG. 2 is a plan view of a positioning device using the present invention.

FIG. 3 is a side view showing a state of positioning using the present invention.

FIG. 4 is a perspective view showing a conventional positioning device.

[Explanation of symbols]

1 work 2 pin 3 suction head 10a, 10b, 10c, 10d rotating roller 11 escape groove 12 push-up rod

Continuation of the front page (56) Reference JP-A-5-299895 (JP, A) JP-A-2-207599 (JP, A) JP-A-2000-133993 (JP, A) JP-A-7-294600 (JP, A) Actual Kaihei 1-113400 (JP, U) Actual Kaihei 5-20397 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) B23P 19/00-21/00 B25J 15 / 06 H05K 13/00-13/04

Claims (5)

(57) [Claims] 1. A positioning device for a minute work having a plurality of side surfaces, wherein a plurality of rotating rollers are arranged in parallel to the respective side surfaces of the plurality of side surfaces and in a horizontal direction, and the plurality of rotating rollers are arranged. A fine work positioning device, which positions a work by vertically inserting and pulling up the fine work adsorbed by a suction head from a space surrounded by the above. 2. The plurality of rotating rollers having the same maximum outer diameter and the same rotation axis on the same plane, and the plurality of inner rollers formed by intersecting the maximum outer peripheral portion of the rotating roller with the same plane. The positioning device for a minute work according to claim 1, wherein each of the straight lines is extended, and a polygon surrounded by the straight lines is similar to the minute work and slightly larger than the minute work. 3. The positioning device for a minute work according to claim 2, wherein an escape groove for avoiding a protruding portion on a side surface of the minute work is provided on an outer circumference of the rotary roller. 4. A push-up bar vertically moving in the vertical direction is arranged in the space surrounded by the plurality of rotating rollers, and the push-up bar always acts as an urging force to push upward and is applied downward from above. The positioning device for a microscopic work according to claim 3, wherein the positioning device lowers against the biasing force by an external force. 5. The micro workpiece positioning device according to claim 4, wherein the pushing force of the push-up rod is obtained by a compression spring.