WO2019143091A1

WO2019143091A1 - Wafer prober

Info

Publication number: WO2019143091A1
Application number: PCT/KR2019/000573
Authority: WO
Inventors: 박남우; 박기택
Original assignee: 주식회사 쎄믹스
Priority date: 2018-01-19
Filing date: 2019-01-15
Publication date: 2019-07-25

Abstract

The present invention relates to a wafer prober. The wafer prober has a wafer probing stage comprising: a lower plate; multiple elevating columns mounted on the upper surface of the lower plate; and an upper plate mounted on the upper-end portion of the multiple elevating columns. Each of the multiple elevating columns is configured to move upward/downward between the upper plate and the lower plate, and the height and inclination of the upper plate are adjusted according to the upward/downward movement of the elevating columns. The wafer probing stage adjusts the height of each elevating column according to the load applied to each elevating column such that the height of a chuck placed above the upper plate and the inclination or flatness of the chuck can be adjusted accordingly.

Description

Wafer Prober

The present invention relates to a wafer prober, and more particularly, to a wafer prober capable of adjusting the height of the chuck and the inclination of the chuck by independently arranging a plurality of elevating columns independently driven under the chuck and independently adjusting the height of the elevating columns And as a result, the contact surface between the wafer placed on the chuck and the probe card in contact with the wafer can maintain a flat posture.

Wafer prober, a semiconductor inspection device, tests the electrical characteristics of semiconductor devices fabricated on a wafer, just before entering a post-process (a post-process) on wafers that have been completely pre-processed, It is equipment to check whether there is.

Generally, a wafer prober is provided with a stage capable of being driven in vertical and horizontal directions, a chuck which is seated on the stage and on which a wafer is mounted, an electrical test apparatus for inspecting the wafer, And a probe card in contact with the wafer.

Probe card probes range from dozens of electrical test pins to tens of thousands of pins, but they are commonly connected to electrical test equipment and the electrical test equipment is mechanically fastened to the top plate of the base frame. Thus, since the probe card connected to the electrical test apparatus is fastened to the fixed frame upper plate, the probe of the probe card always maintains the fixed position and state. That is, the probe of the prober card is fixedly positioned at the first fixed position, and the chuck moves up and down and left / right by the movement of the stage to come into contact with the probe.

On the other hand, a stage disposed at a lower portion of the chuck is composed of a horizontal moving mechanism, a vertical moving mechanism, and a rotating mechanism, and serves to move the chuck to any desired point. The horizontal movement mechanism includes a Y-axis stage for moving the chuck in the front-back direction and an X-axis stage for moving the chuck in the left-right direction, and the vertical movement mechanism comprises a Z-axis stage for moving the chuck in the vertical direction.

Conventional horizontal and vertical moving mechanisms include a base frame, a Y-axis stage mounted on the base frame, an X-axis stage mounted on the Y-axis stage, and a Z-axis stage mounted on the X-axis stage. That is, the conventional horizontal and vertical moving mechanism is configured such that a Y-axis stage, an X-axis stage, and a Z-axis stage are sequentially stacked on a base frame.

The conventional vertical movement mechanism is constituted by a Z-axis stage composed of a single vertical column, and the height of the chuck can be adjusted as the vertical movement mechanism moves up and down in the vertical direction.

On the other hand, in the conventional wafer prober, when the inspection is performed at the edge of the chuck, the chuck is warped due to the eccentric load. Theoretically, the chuck should be designed to have a rigid structure and rigidity, but in fact, the chuck is distorted by the eccentric load. Actually, when a probe placed on a chuck on a Z-axis stage is brought into contact with a probe by moving the Z-axis stage, which is a vertical movement mechanism, upward in a state where the probe of the probe card is fixed, And a contact load is applied to the surface of the lower chuck. At this time, the chuck can not stand and the surface of the chuck is twisted to cause an undesired tilt, so that some of the probes of the probe card are not properly contacted, resulting in poor contact.

Thus, as the single Z-axis stage rises, eccentric load is generated by the contact of the probes of the probe card with respect to a partial area of the wafer mounted on the chuck, and a tilt is generated in the chuck. To solve this problem, it is necessary to adjust the inclination of the chuck so that the chuck can maintain the flatness.

However, since the vertical movement mechanism of the conventional wafer prober is constituted by only a Z-axis stage composed of a single vertical column, it is not possible to provide an appropriate rigidity to the entire region of the chuck and also difficult to adjust the slope of the chuck have.

SUMMARY OF THE INVENTION An object of the present invention is to provide a wafer prober capable of adjusting the height of a chuck as well as easily adjusting a tilt of the chuck and capable of providing appropriate rigidity to the entire region of the chuck .

According to an aspect of the present invention, there is provided a wafer prober having a wafer chuck for holding a wafer and a wafer probing stage for moving or rotating the chuck, The probing stage includes a lower plate; A plurality of elevating columns mounted on an upper surface of the lower plate; And an upper plate mounted on an upper end of the plurality of elevated columns, wherein each of the elevated columns is configured to move up and down between the upper plate and the lower plate, The height and slope are adjusted accordingly.

In the wafer prober according to the present invention, the plurality of elevated columns are independently driven, and the plurality of elevated columns are uniformly spaced with respect to the center of the upper surface of the lower plate .

In the wafer prober according to the above aspect, it is preferable that the wafer probing stage further comprises a force tilt holding module for changing only the tilt of the upper plate without changing the position of the center of the plurality of elevating columns.

In the wafer prober according to the above-described features, the wafer probing stage may include: a load measuring sensor mounted on each of the plurality of elevating columns to sense a load applied to each elevating column; And a preload adjusting module between the lower surface of the upper plate and the upper surface of the elevating column, wherein the load measuring sensor is mounted on the upper or lower portion of the preload adjusting module.

The wafer probing stage of the wafer prober according to the present invention is configured such that a plurality of elevating modules are disposed apart from each other and a chuck for mounting a wafer thereon is disposed thereon so that the height of the chuck can be adjusted, It is also possible to adjust.

The wafer probing stage of the wafer prober according to the present invention is a wafer probing stage in which a plurality of elevation modules are independently driven and a load measuring sensor is mounted to each elevation module, The load can be accurately measured.

Therefore, the wafer probing stage of the wafer prober according to the present invention adjusts the overall height of the plurality of elevator posts to move to the pre-registration position for the initial contact between the wafer and the probe card, The slope of the chuck is measured and the height of each of the plurality of elevating columns is finely adjusted according to the measured slope to maintain the flatness of the chuck.

1 is a perspective view of a wafer probing stage in a state where a chuck is mounted on a wafer prober according to a preferred embodiment of the present invention.

2 is an exploded perspective view of the wafer probing stage with the chuck of Fig. 1 mounted thereon.

FIG. 3 is a partial perspective view showing a state of a lower structure in which a plurality of elevating columns are mounted on a lower plate in a wafer prober according to a preferred embodiment of the present invention, and FIG. 4 is a plan view of FIG.

5 is a partial perspective view showing a state of a superstructure in which a force tilt adjustment module is mounted on a top plate in a wafer prober according to a preferred embodiment of the present invention.

FIG. 6 is a partial perspective view of a wafer prober according to a preferred embodiment of the present invention, in which a force tilt adjusting module and a preload adjusting module are mounted.

FIG. 7 and FIG. 8 are conceptual diagrams for explaining the movement of the upper plate in the horizontal direction in the wafer prober according to the preferred embodiment of the present invention, which is generated in accordance with the vertical movement of the vertical column.

The wafer probing stage of the wafer prober according to the present invention is configured such that a plurality of elevating columns are spaced apart from each other with respect to a center point of the chuck and are independently drivable from each other and a load applied to each elevating column is sensed, It is possible to control the height of the chuck and the inclination or flatness of the chuck by controlling the height of each elevating column according to the load applied to the elevating column.

Hereinafter, the configuration and operation of a wafer prober according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 is a perspective view of a wafer probing stage 10 with a chuck 20 mounted thereon in a wafer prober according to a preferred embodiment of the present invention. 2 is an exploded perspective view of the wafer probing stage with the chuck of Fig. 1 mounted thereon.

1 and 2, the wafer probing stage 10 of the wafer prober according to the present embodiment includes a lower plate 100, a plurality of

elevating posts

110, 112 and 114, a plurality of load measuring sensors 120 122 and 124, power

tilt holding modules

140, 142 and 144,

preload adjusting modules

150, 152 and 154, an upper plate 160 and a rotary module 170. A chuck for mounting the wafer may be mounted on the upper surface of the upper plate. The wafer prober according to the present invention can control the height of the chuck and the inclination of the chuck by driving the wafer probing stage. In the drawings of the present invention, three elevating columns are exemplarily shown, but this is for convenience of explanation and is not intended to limit the scope of the present invention.

The lower plate 100 may be mounted on the base frame of the wafer prober or on the XY stage of the wafer prober.

3 to 4, the

elevating columns

110, 112, and 114 are equipments having a step motor or the like mounted therein to raise or lower the upper end. The plurality of elevating columns are mounted and spaced apart from each other between the upper surface of the lower plate 100 and the lower surface of the upper plate 160.

At least two or more of the elevated columns may be mounted. In particular, when the elevated columns are composed of three elevated columns, the elevated columns may be uniformly spaced apart from each other with respect to the center of the upper surface of the lower plate and arranged in a triangular shape. Each of the plurality of elevating columns moves along the vertical direction with respect to the lower plate and is driven independently of each other, and the elevation and inclination of the upper plate can be adjusted according to the independent upward and downward movement of the elevating columns .

The plurality of

load measuring sensors

120, 122 and 124 are composed of a load cell or the like and are mounted on the upper ends of the plurality of elevating columns to sense the loads applied to the elevating columns and output them.

6, the force tilt holding module 140 is a module for changing only the slope of the upper plate without changing the position of the center of the plurality of elevating columns, and may be a linear motion guide Quot;). &Lt; / RTI > The linear movement guide includes LM guide rails 146 and LM guide blocks 148 coupled thereto.

The LM guide block 148 is fixedly mounted to each of upper ends of the elevating columns abutting the lower surface of the upper plate and is coupled to the LM guide rail. The LM guide rail 146 is mounted on the lower surface of the upper plate, and is engaged with each LM guide block of the elevating columns. At this time, the LM guide rail may be disposed such that the longitudinal direction thereof is directed toward the center of the upper plate, and is moved horizontally toward the center or circumferential direction of the upper plate in accordance with the change of the vertical height of the vertical column.

With the force tilt holding module having the above-described configuration, when one of the elevating posts moves in the vertical direction, the LM guide moves in the horizontal direction, and the inclination of the upper plate Only. It is preferable that the LM guide rail is disposed so that the block coupled to the LM guide rail can move toward the center of the triangle formed by the plurality of elevating posts.

Referring to FIG. 6, the pre-pressure regulating module 150 is mounted between the upper portion of the plurality of load measuring sensors and the force tilt holding module to provide a predetermined preload. Meanwhile, the pre-pressure adjusting module may be installed below the load measuring sensor or may be installed on the upper portion of the force tilt holding module.

The preload adjusting module 150 includes a preload adjusting screw 155 mounted at the lower end of the block; A spherical socket (157) mounted on an upper portion of the load measuring sensor (120) and having an upper surface in a spherical shape; A lower surface mounted on the upper surface of the spherical socket, and a lock nut 158 coupled to the preload adjusting screw; And a preloading plate spring (159) coupled to the outer circumferential surface of the lock nut and the spherical socket, so that the lock nut and the spherical socket provide a spherical contact preload by the preloading plate spring.

The rotary module 170 is a module configured to rotate the lower plate 100, and the bearing may be arranged to face the outer circumferential surface of the lower plate 100. In this connection, in the conventional wafer prober, it is general that the rotation part with respect to the chuck is configured to be narrowly mounted on the upper end of the Z-axis for vertical lift and to be embedded at the lower end of the Z-axis. In such a conventional structure, when a high load of about 600 kg or more is applied to the chuck, not only the Z axis as a vertical movement mechanism but also a large amount of external force is applied to the rotating portion mounted on the upper or lower end of the Z axis. do. In addition, when the shape of the cantilever pin of the probe card is a pogo pin having a slope of about 15 to 30 degrees, the vertical movement mechanism and the rotation part of the chuck are required to have rigidity with respect to vertical and horizontal directions. In consideration of this point, the vertical movement mechanism according to the present invention is characterized in that the rotary module 170 is disposed outside the plurality of elevating columns of the wafer probing stage, and its position is also located at the intermediate position of the elevating column, Even if a high load is applied, the influence on the rotary module is small.

By disposing the rotary module 170 in the same manner as the lower plate on which the plurality of elevating columns are mounted, it is possible to make the elevating columns free from height restriction in space and to manufacture the elevating columns with a simpler and lighter structure, So that a more rigid state can be maintained.

The wafer probing stage of the wafer prober according to the present invention having the above-described configuration is advantageous in that the conventional wafer probing stages have a large area and a large volume and have difficulty in finding the space, while the three probing stages of the simplified elevating columns Areas can be used for a variety of purposes. As a result, by applying the wafer probing stage according to the present invention to the wafer prober, the overall size of the wafer prober can be greatly reduced.

Meanwhile, the wafer probing stage according to the present invention is arranged so that the contact force of the probe card applied to the center of the chuck of the wafer prober is very small So that stable stiffness and tilt posture can be maintained. In addition, in the wafer probing stage according to the present invention, the force tilt holding module can maintain an independent force and attitude when the elevating column ascends or descends.

7 and 8 are conceptual diagrams illustrating a movement of the upper plate in the horizontal direction in accordance with the movement of the vertical column in the wafer prober according to the preferred embodiment of the present invention.

7 (b), when the elevating column is elevated, the LM guide mounted so as to cross in the horizontal direction with respect to the upper surface of the vertically arranged elevating column slides in the direction of the center of the triangle by the elevation height of the elevating column And maintains the raised vertical height. At this time, the position of the center of the triangle remains unchanged and only the slope of the upper plate is provided.

7C, when the elevating column is lowered, the LM guide slides in the outer side of the triangle, that is, in the circumferential direction by the descent height of the elevating column, and the lowered vertical height is maintained. At this time, the position of the center of the triangle remains unchanged, and only the tilt of the upper plate is provided.

In the wafer probing stage according to the present invention, the spherical socket of the preload adjusting module is coupled with the load measuring sensor, thereby providing a structure having no clearance with a spherical degree of freedom in the force tilt holding module.

On the other hand, the lock nut of the preload adjusting module has a spherical contact preload with the spherical socket by the preloading plate spring, and the preload provided by the lock nut can be maintained by extending the preloading plate spring using the preload adjusting screw .

On the other hand, the inclination [theta] 2 of one lift column corresponds to the spherical shape of the sphere of the spherical socket, and the horizontal movement amount of the LM guide corresponds to the linear amount of the LM guide.

Referring to FIG. 8, when the lifting module rises by 100 mu m, the LM guide is inclined at an angle of? 2 along the slope of? 1 and slides toward the center of the triangle by L2.

On the other hand, one embodiment of the wafer probing stage of the wafer prober according to the present invention described above may include three elevating columns mounted between the lower plate and the upper plate. In particular, it is preferable that each of the elevated columns is configured to vertically move between an upper plate and a lower plate and be driven independently of each other. It is further preferable that the three elevating columns are uniformly spaced from each other in a triangular shape with respect to the center of the upper surface of the lower plate. According to the above-described structure, in the wafer probe according to the above embodiment, the height and the inclination of the upper plate can be adjusted according to the height of the elevating columns.

The wafer probing stage according to the present embodiment also includes a force tilt holding module as described above, a plurality of load measuring sensors for sensing a load applied to each elevating column, a preload detecting sensor for detecting a load applied to the elevating column, A control module, and a rotator module, which are preferably the same as those described above.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, It will be understood that various changes and modifications may be made without departing from the spirit and scope of the invention. It is to be understood that the present invention may be embodied in many other specific forms without departing from the spirit or essential characteristics thereof.

The wafer probing stage according to the present invention can be used as a mechanism for moving the chuck of the wafer prober up and down.

Claims

A wafer prober having a wafer chuck for holding a wafer and a wafer probing stage for moving or rotating the chuck,

A lower plate;

A plurality of elevating columns mounted on an upper surface of the lower plate; And

An upper plate mounted on an upper end of the plurality of elevating columns;

And each of the plurality of elevating columns is configured to move up and down between the upper plate and the lower plate,

And the height and tilt of the upper plate are adjusted according to the height of the elevating columns.
The wafer prober according to claim 1, wherein the plurality of elevating columns are configured to be driven independently of each other.
The wafer prober according to claim 1, wherein the plurality of elevating columns are uniformly spaced from each other with respect to a center point of an upper surface of the lower plate.
The wafer prober according to claim 1, wherein the wafer probing stage further comprises a force tilt holding module for changing only the slope of the upper plate without changing the position of the center of the plurality of elevating posts.
[5] The apparatus of claim 4, wherein the force tilt holding module comprises a linear motion guide,

LM guide blocks mounted on each of the upper ends of the elevating columns abutting the lower surface of the upper plate; And

LM guide rails (Linear Motion Guides) mounted on a lower surface of the upper plate and coupled with each block of the elevating columns;

When one of the elevating columns moves in the vertical direction, the LM guide block moves in the horizontal direction along the LM guide rail, so that only the slope of the upper plate changes without changing the position of the center of the elevating columns Wafer prober.
The method of claim 1, wherein the wafer probing stage

A plurality of load measuring sensors mounted on each of the plurality of elevating columns to sense loads applied to the elevating columns;

Further comprising a wafer prober.
7. The apparatus of claim 6, wherein the wafer prober

Further comprising a preload adjusting module between the lower surface of the upper plate and the upper surface of the elevating column,

Wherein the load measuring sensor is mounted on an upper portion or a lower portion of the preload adjusting module.
[8] The apparatus of claim 7, wherein the pre-

Preload adjustment screw mounted at the bottom of the block;

A spherical socket mounted on an upper portion of the load measuring sensor and having an upper surface in a spherical shape;

A lock nut mounted on an upper surface of the spherical socket and coupled to the preload adjusting screw; And

A preloading plate spring coupled to an outer circumferential surface of the lock nut and the spherical socket;

Wherein the lock nut and the spherical socket provide a spherical contact preload by the preloading leaf spring.
The wafer prober according to claim 1, wherein the chuck is disposed on the top plate of the wafer probing stage.
The method of claim 1, wherein the wafer probing stage

Further comprising a rotator module configured to rotate the lower plate.
A wafer prober having a wafer chuck for holding a wafer and a wafer probing stage for moving or rotating the chuck,

A lower plate;

Three elevating pillars mounted on the upper surface of the lower plate; And

An upper plate mounted on an upper end of the three elevated columns;

And each of the three elevating columns is configured to vertically move between an upper plate and a lower plate,

And the height and tilt of the upper plate are adjusted according to the height of the elevating columns.
12. The wafer prober according to claim 11, wherein the three lift columns are configured to be driven independently of each other.
12. The wafer prober according to claim 11, wherein the three elevating columns are uniformly spaced from each other in a triangular shape with respect to a center point of an upper surface of the lower plate.
The wafer prober according to claim 11, wherein the wafer probing stage further comprises a force tilt holding module for changing only the slope of the top plate without changing the center position of the three elevating columns.
12. The method of claim 11, wherein the wafer probing stage

A plurality of load measuring sensors mounted on each of the three elevating columns to sense loads applied to the elevating columns; And

Further comprising a preload adjusting module between the lower surface of the upper plate and the upper surface of the elevating column,

Wherein the load measuring sensor is mounted on an upper portion or a lower portion of the preload adjusting module.