JPH0611542A - Gravity reduction mechanism - Google Patents

Abstract

PURPOSE:To move a gravimetric object by applying force slightly for improving operability by applying the repulsion force of a spring unit to the flange of a spindle. CONSTITUTION:A gas spring 26 fills a spring main body 28 with a specific gas and energizes a rod part 30 in the longitudinal direction of the main body 28 by gas pressure. A test head 8 is rotated in directions A and B in reference to a spindle 22. The rod 30 of the gas spring 26 is subjected to elastic force toward the lower direction so that it is constantly pushed from the gas spring main body 28 and the elastic force is transferred to a connection pin 56 placed at a flange 46 via a wire 58, thus generating a moment which is nearly equal to that which is generated by the head 8 for the spindle 22 so that the latter is canceled. Therefore, a gravimetric object can be moved by applying force slightly, operability can be improved, and then an occupation space can be reduced using an expandable and contractible spring unit.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a gravity reduction mechanism.

[0001]

BACKGROUND OF THE INVENTION Generally, a prober device is known as a device for inspecting whether or not each chip formed on a semiconductor wafer operates electrically normally. This prober device is, for example, as shown in FIGS. 7 and 8, tilted on the prober body 2 via a prober body 2 on which a semiconductor wafer is mounted and fixed, and a rotatable spindle 4 via an arm 6. It has a test head 8 freely provided, and a probe needle (not shown) provided on the test head 8 is brought into contact with the electrode pad of each chip of the wafer, and a tester (not shown) is provided through the probe needle. The electrical characteristics of each chip are inspected by applying a measurement pattern.

By the way, when checking the probe needles, checking the needle traces on the wafer, and replacing the probe card, the test head 8 is tilted up and down around the spindle 4 as shown by the phantom line in the figure, or the finished product is checked. To do this, you must fully deploy 180 degrees horizontally on the opposite side. In this case, the operation of deploying the test head 8 is generally performed by an operator, but since the weight of the test head 8 usually reaches 20 to 300 kg, the operator can easily deploy the test head 8. A counterweight 1 is attached to one end of the spindle 4 as a gravity reducing mechanism.
It is practiced to attach 0 to make the moment applied to the main shaft substantially zero. Further, as another gravity reducing mechanism, a plurality of torsion coil springs are attached to the main shaft 4, and the torsion moment generated by these springs is utilized to reduce the force required when the test head 8 is deployed. There is. Further, as shown in FIGS. 9 and 10, a gas spring 12 is attached to one end of the main shaft 4 via an arm 11 and the elastic force of the gas spring is applied to the arm 11 to reduce the moment applied to the main shaft 4. Things are also being done.

[0003]

By the way, when the counterweight 10 is provided as described above, the operator can easily move the test head 8 regardless of the deployment angle of the test head 8 and the operability is extremely high. However, an improvement in that the weight of the entire apparatus is increased by the amount of the counterweight 10 provided, and for example, the strength of the net-like floor portion that sucks the downflow of clean air must be increased by that amount. There was a point. Further, the counterweight 10 moves as the test head 8 is deployed, but the protective cover 12 must be provided so as to cover the entire moving range thereof in order to ensure safety. For this reason, the floor area occupied by the apparatus becomes large, and in particular, the cost of the unit area of the clean room in which this type of apparatus is arranged is very high, so there is an improvement that the equipment cost as a whole is forced to soar. there were.

On the other hand, when the torsion coil spring is used as the gravity reducing mechanism, the installation space is small, but when the spring contracts, an idle area is always generated and the spring does not function. For this reason, the spring did not function and was very unstable when the test head 8 stood up and down. Further, when the test head 8 is located on the side of the prober main body 2 and when the test head 8 is deployed 180 degrees and located on the opposite side, the amount of depression of the spring is different. If the moment applied to the spindle 4 is set to zero when the test head 8 is tilted down, in order to tilt the test head 8 to the opposite side by 180 degrees,
For example, the test head 8 had to be pressed down with a force of 20 to 30 kg, and the operability as a whole was considerably inferior.

Further, when the above-mentioned torsion coil spring is used, even if a large number of springs are provided in a range where the installation space does not become excessively large, the gravity reducing force as a whole is about 50 kg. It is difficult to cope with the increase in the size and weight of the device due to the high integration of the semiconductor device as described above. When a gas spring is used as the gravity reducing mechanism, the gas spring must be attached to the tip of the main shaft 4 in order to prevent interference between the gas spring and the main shaft 4, and the occupied space cannot be excessively large. Therefore, the number of gas springs that can be used is limited to a few. Moreover, since the weight of the test head 8 must be supported by several gas springs, the distance from the center of the main shaft 4 to the mounting portion of the gas spring must be lengthened to increase the moment. In this case, when the test head 8 is vertically erected, the gas spring is most extended and the elastic force is minimum, but when the test head 8 is tilted toward the prober main body 2 side,
When it is deployed at 80 degrees and is located on the opposite side, the gas spring is pushed most and the maximum elastic force is generated. This difference in elastic force is a dozen or more kilometers. Due to this difference in elastic force, for example, if the moment applied to the spindle 4 is set to zero when the test head 8 stands up and down, a test is performed. In order to rotate the head 8 from the standing state to the side of the prober main body 2 or to the opposite side, for example, the test head must be pressed with a force of 10 Kg to 20 Kg, and the operability as a whole is inferior. Had a point. Further, as described above, there is also an improvement in that the floor area occupied by the device is increased by mounting the gas spring. The present invention has been made to pay attention to the above problems and to solve them effectively. An object of the present invention is to provide a gravity reducing mechanism that is excellent in operability without increasing the occupied space.

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention rotates a heavy object mounted and fixed on a spindle that is rotatable at least a predetermined angle when rotating the heavy object. In a gravity reduction mechanism for reducing the force required to move, a flange is fixed to the main shaft, and a spring unit is provided that is extendable in the longitudinal direction in a direction orthogonal to the main shaft and the elastic force of the spring unit is provided. Is provided to the flange.

[0007]

Since the present invention is configured as described above, the elastic force generated from one end of the spring unit is applied to the flange fixed to the main shaft. This elastic force does not change much even when the heavy object falls from the vertical standing state to the horizontal direction because the distance from the place where this elastic force is applied to the center of rotation is small, and as a result,
The difference between the moment generated by the weight of the heavy object and the moment generated by the elastic force of the spring unit is small, and it can be rotated with a small force over the entire 180-degree deployment range, improving operability. Becomes

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a gravity reducing mechanism according to the present invention will be described in detail below with reference to the accompanying drawings. 1 is a front view showing an embodiment of a gravity reducing mechanism according to the present invention, FIG. 2 is a schematic side view of the mechanism shown in FIG. 1, and FIG. 3 is a schematic plan view of the mechanism shown in FIG. The same parts as those of the conventional device are designated by the same reference numerals. As shown in the drawings, in this embodiment, a case where the gravity reducing mechanism of the present invention is applied to a prober device will be described.

The prober device 14 has a prober main body 2 on which an object to be inspected, for example, a semiconductor wafer W is mounted and fixed. The wafer W has an X, Y, Z stage (not shown). It is configured to be placed on the top and to be aligned in the horizontal plane and in the vertical direction. Above the prober main body 2, a test head 8 as a heavy load for inspecting the electrical characteristics of each chip formed on the wafer W is provided so as to be developed as described later. On the connection between the test head 8 and the prober main body 2, there is a connection ring or a wiring assembly 70, and the probe card 69 is provided via this connection ring. The probe needle 16 of the probe card 69 is in contact with the electrode pad of each chip formed on the wafer W, and a measurement pattern is applied from a tester (not shown) so that the electrical characteristics of each chip can be inspected. Has been done.

The test head 8 houses a large number of electronic devices for interfacing electrical signals between the tester 7 and the probe needle 16, and its weight is 20.
It weighs up to 200 kg. This test head 8
It is connected to the gravity reducing mechanism 19 of the present invention to reduce the gravity when it is deployed. That is, the test head 8 is provided with two columns 18 which are provided upright on the side portion of the prober body 2.
It is attached and fixed to a main shaft 22 spanned between two via two arms 24, and the main shaft 22 is rotatably supported on the upper part of the column 18 via bearing portions 20 at both ends thereof. ing. Therefore, the test head 8 which is a heavy object can be deployed 180 degrees around the main shaft 22 as shown in FIG.

Then, in order to reduce the gravity of the test head 8, a spring unit capable of expanding and contracting in the longitudinal direction,
For example, the gas spring 26 is used. The gas spring 26 is provided along a direction orthogonal to the axial direction of the main shaft 22. Although only two gas springs 26 are shown in the illustrated example, actually about ten gas springs 26 are provided, and the number thereof is appropriately increased or decreased in accordance with the weight of the heavy object to be reduced. it can. The gas spring 26 is configured such that, for example, a cylindrical gas spring body 28 is filled with a gas having a predetermined pressure, such as air, and the rod portion 30 is biased in the longitudinal direction of the gas spring body 28 by the pressure of this gas. Has been done.

The entire gas spring 26 is housed in a rectangular parallelepiped protective box 31, and the upper end portion of the gas spring body 28 is reinforced by two reinforcements extending in parallel between the two columns 18. The tip of the rod portion 30 at the other end, which is fixed to the beam 32 side, is supported so as to be guided and movable toward the pair of guide plates 34. Specifically, the above-mentioned two reinforcing beams 3
A reinforcing plate 36 is slid in a vertical direction between the two and is fixed to the reinforcing plate 36. The adjusting screw 3 is attached to the reinforcing plate 36.
A movable plate 40 is provided so as to be adjustable in the up-down direction via the switch 8. The upper end of the gas spring body 28 is attached and fixed to the movable plate 40 so as to be orthogonal to the movable plate 40. The gas spring body 28 is slightly inclined with respect to the vertical direction so that the overall height is lowered. Has been done. A guide pin 42 is fixed to the tip of the rod portion 30. The guide pin 42 is a long hole-shaped guide hole formed in the pair of guide plates 34 along the protruding / retracting direction of the rod portion 30. Both ends thereof are loosely fitted in 44 so as to be movable.

On the other hand, a flange 46 having a predetermined diameter as shown in FIG. 5 is attached to the portion of the main shaft 22 corresponding to the gas spring 26. Specifically, the flange 46 includes a ring-shaped flange portion 48 and a ring-shaped tightening portion 50 that is connected to the flange portion 48, and has a notch 52 on one side. And this notched tightening portion 5
It is configured so that the flange 46 is securely fixed to the main shaft 22 by inserting the bolt 54 into the 0 and tightening the bolt 54 to reduce the ring diameter of the tightening portion 50. A connection pin 56 is fixedly provided on the flange portion 48 so as to penetrate therethrough. It is preferable that the attachment position of the connection pin 56 be located on an extended line of a straight line connecting the center of gravity G of the test head 8 and the center point O of the main shaft 22.

The both ends of the connecting pin 56 and the both ends of the guide pin 42 provided at the tip of the load portion 30 are firmly connected by a strong wire 58. Therefore, the connecting pin 56 also moves up and down in an arc shape in response to the rotation of the main shaft 22, but at this time, the elastic force of the gas spring 26 acts as a moment to urge the main shaft 22 downward via the wire 58. It is configured to generate a moment in the opposite direction that is transmitted and approximately equalizes with the moment generated by the test head 8. For this reason, the attachment position of the connection pin 56 on the flange portion 48 is
When the test head 8 stands upright in the vertical direction as shown by one of the phantom lines in FIG. 1 and its center of gravity G is located right above the main shaft 22, that is, when the main shaft 22 is expanded by an angle of 90 degrees. It is set so as to be located on the line connecting the center point O and the gas spring 26.

The mounting structure of each gas spring 26 is as follows.
All are attached in the same manner as described above. For example, when the weight of the test head 8 is about 100 kg, about 10 gas springs are used depending on the capacity of the gas spring 26. When the distance L1 between the center point O of the main shaft 22 and the center of gravity G of the test head 8 is, for example, 600 mm, the distance L2 between the center point O of the main shaft 22 and the connection pin 56 is, for example, about 60 mm. Set. The reason why the distance L2 can be shortened in this way is that the characteristic of the gas spring can exhibit a strong elastic force in a short stroke. still,
A side desk (not shown) is provided to support the load of the test head 8 when the test head 8 is unfolded 180 degrees from the prober body 2 side as shown by an imaginary line.

Next, the operation of this embodiment configured as described above will be described. First, when inspecting the electrical characteristics of a semiconductor wafer W, which is an object to be inspected, and a finished product using this chip using this prober device, the probe is developed 90 degrees as shown by a phantom line, or 180 degrees. The test head 8 in the unfolded state and maintained in the horizontal state is rotated in the A direction, that is, the direction of the prober main body 2 to be connected to the connection ring or the wiring assembly 70. At this time, the wafer W is suction-fixed to the XY stage 72 of the prober main body 2 and accurately positioned at an arbitrary position. In this state, the probe needle 16 of the probe card 69 is attached to the wafer W.
The electrical pattern of each chip is inspected by contacting the electrode pad of each chip above and applying a measurement pattern to the chip from a tester (not shown) via the probe needle 16.

Further, in a state where the test head 8 is expanded 180 degrees to the opposite side of the prober main body 2 and maintained in a horizontal state, a finished chip or the like is inspected. In this way, the test head 8 is operated by the operator as needed by the spindle 22.
Is deployed or rotated in the directions of the arrow A and the arrow B around the center. In this case, the force required to rotate the test head 8 is reduced by the gravity reducing mechanism 19 so that the test head 8 can be easily rotated. That is, the rod 30 of the gas spring 26 is always given an elastic force downward in the drawing so as to be pushed out from the gas spring main body 28, and this elastic force is provided on the flange portion 48 via the wire 58. Is transmitted to the connecting pin 56, and a moment substantially equal thereto is generated so as to cancel the moment generated by the test head 8 with respect to the main shaft 22.

In this case, when the test head 8 is located on the prober body 2 side as shown by the solid line, the connection pin 56 provided on the flange portion 48 is located at the first position P1 and the test head 8 is located at the first position P1. The connection pin 56 moves in the direction of arrow C as it is expanded, and the connection pin 56 is located at the second position P when the test head 8 is erected. Further, when the test head 8 is rotated and expanded by 180 degrees, the connection pin 56 reaches the third position P3. Also,
When the test head 8 is returned to the original position indicated by the solid line on the prober body 2 side, the connecting pin 56 returns in the direction indicated by the arrow D along the route opposite to the above. Here, when the test head 8 is maintained in the horizontal state, the connection pin 5
Since 6 is located at the first or third position P1 or P3, the wire 58 is pulled upward and the rod portion 30 is pushed most into the gas spring body 28, so that the maximum elastic force is exerted. At this time, the guide pin 42 provided on the rod portion 30 moves upward while being guided along the guide hole 44 of the guide plate 34, and is located at the position P4 as shown in FIG.

Further, since the connecting pin 56 is positioned at the second position P2 when the test head 8 is erected, the wire 58 is pulled downward so that the lot portion 30 projects most from the gas spring body 28. The minimum resilience is demonstrated. At this time, the guide pin 42 provided in the lot section 30 is located at P5 as shown in FIG.
Therefore, when the test head 8 is horizontal, the wire 58
Is pulled with the maximum tension, but the distance between P4 and P5 is relatively small, and the change in the elastic force of the gas spring due to the change in the pushing amount is relatively small. The difference in tension is small. As a result, regardless of the angle of the test head 8, the gas spring can generate a moment in the opposite direction corresponding to the magnitude of the moment generated by the test head 8. Therefore, the operator can rotate the test head 8 with a slight force regardless of the angle of the test head 8, and the operability can be greatly improved.

As a result of the experiment, it was possible to rotate the test head 8 with a force of 2 kg weight or less at any angle within the rotation range of 180 degrees, and good results could be obtained. Further, even if a plurality of, for example, ten gas springs 26 are provided in parallel, the occupied space can be significantly reduced as compared with the case where the counterweight of the conventional device is used. For example, when the device of the present invention is applied to a prober device having two measurement stages, for example, an occupied space of 1095 × 2500 mm is required, and in the case of the same type of prober device using a conventional counterweight (1495 × 3342 mm). The occupied space can be significantly reduced in comparison.

Further, since the weight of the test head 8 is reduced by the plurality of gas springs 26, even if a part of the test head 8 fails, the test head 8 does not suddenly rotate and the safety is improved. Can also be kept high. Also, it goes without saying that the defective gas spring 26 is replaced. Further, since the tightening portion 50 of the flange 46 is provided with the notch 52 and is attachable / detachable by the bolt 54, the setting position and the like of the connection pin 56 can be easily adjusted. Further, in order to change the elastic force generated by the gas spring 26, the pressure of the compressed air filled is changed, or the movable plate 40 having the upper end attached and fixed.
May be moved up and down by the adjusting screw 8.

Although the gas spring 26 is provided as the spring unit in the above embodiment, instead of this, the coil spring 6 wound in a spiral shape as shown in FIG.
You may make it provide 0. That is, the coil spring 6
The upper hook 62 provided at one end of the No. 0 is engaged with the engaging hole of the flange portion 48 of the flange 46, and the lower hook 64 provided at the other end is provided at the same position as the previous guide plate 34.
It may be made to engage with the engagement hole 68 of No. 6. Also,
Instead of the coil spring 60, a spiral spring 61 may be used as shown in FIG. That is, the end of the spiral spring 61 may be attached to the flange 48 via the hook 63, and the shaft 65 passing through the center of the spiral spring may be engaged with the engaging hole 69 of the engaging plate 67. In the above embodiment,
The case where the gravity reducing mechanism of the present invention is provided in the prober device has been described, but the present invention is not limited to this and can be applied to any device as long as it is necessary to reduce gravity.

[0023]

As described above, according to the gravity reducing mechanism of the present invention, the following excellent operational effects can be exhibited. The heavy object can be moved with a slight force over the entire range of rotation of the heavy object, and therefore the operability can be greatly improved. Further, since the expandable / contractible spring unit is used, the occupied space can be significantly reduced as compared with the case where the conventional counterweight is used.

[Brief description of drawings]

FIG. 1 is a schematic front view showing an embodiment of a gravity reducing mechanism according to the present invention.

FIG. 2 is a schematic side view of the mechanism shown in FIG.

3 is a schematic plan view of the mechanism shown in FIG. 1. FIG.

FIG. 4 is a plan view showing a flange used in the present invention.

FIG. 5 is a plan view showing a coil spring wound in a temple shape used in an embodiment of the present invention.

FIG. 6 is a plan view showing a spiral spring used in an embodiment of the present invention.

FIG. 7 is a schematic side view showing a prober device using a conventional gravity reducing mechanism.

FIG. 8 is a schematic plan view of the device shown in FIG.

FIG. 9 is a schematic side view showing a prober device using a conventional gravity reducing mechanism.

FIG. 10 is a schematic plan view of the device shown in FIG.

[Explanation of symbols]

 2 Prober main body 8 Test head (heavy load) 14 Prober device 16 Probe needle 19 Gravity reduction mechanism 22 Spindle 26 Gas spring (spring unit) 28 Gas spring main body 30 Rod part 42 Guide pin 46 Flange 56 Connection pin 60 Coil spring

Claims (2)

[Claims] 1. A gravity reducing mechanism for reducing a force required to rotate a heavy object, which is attached and fixed to a main shaft rotatable at least a predetermined angle, in a gravity reducing mechanism, wherein a flange is provided on the main shaft. A gravity reducing mechanism characterized in that a spring unit that is fixed and is capable of expanding and contracting in the longitudinal direction in a direction orthogonal to the main axis is provided and that the elastic force of the spring unit is applied to the flange. . 2. The gravity reducing mechanism according to claim 1, wherein the spring unit is a gas spring, a coil spring wound in a spiral shape, or a spiral spring.