JP2022174370A - Prober and maintenance method thereof - Google Patents

Abstract

To provide a prober capable of simplifying maintenance and shortening a downtime, and a maintenance method thereof.SOLUTION: A prober (10) includes a measuring portion (16) including a wafer chuck (50) that holds a wafer, a probe card (54) having a plurality of probes on the surface facing the wafer chuck, a test head (18) located on the opposite side of the probe card from the wafer chuck, a pogo frame (56) interposed between the probe card and the test head and electrically connecting the probe card and the test head, and a head stage (58) that holds the pogo frame, and the pogo frame is constructed so as to be pulled out to the maintenance area integrally with the head stage.SELECTED DRAWING: Figure 13

Description

The present invention relates to a prober and its maintenance method, and more particularly to a prober for inspecting a plurality of semiconductor devices formed on a semiconductor wafer and its maintenance method.

In the manufacturing process of semiconductor devices, various inspections are performed in various manufacturing processes for quality assurance and yield improvement. For example, in wafer level inspection, at the stage where a plurality of chips corresponding to individual semiconductor devices are formed on a semiconductor wafer (hereinafter referred to as a wafer), the electrodes (pads) of the semiconductor devices are connected to a tester and test signals are generated. supply. Then, a signal output by the semiconductor device according to the test signal is measured by a tester to electrically test whether the semiconductor device operates normally.

2. Description of the Related Art In recent years, as semiconductor devices have become finer and more highly integrated, electrodes on wafers have become smaller, and the number of chips formed on one wafer has increased significantly. Along with this, the time required to inspect one wafer with a prober is also increasing, and an improvement in throughput is required. Therefore, in order to improve the throughput, a multi-stage prober is known, which inspects a plurality of chips simultaneously by arranging a large number of probes in a multi-stage manner (see Patent Documents 1 and 2).

JP 2019-149447 A JP 2015-088555 A

In a multi-stage prober, maintenance of a pogo frame having a plurality of pogo pins and a test head leads to downtime of the apparatus, which is a heavy burden. Therefore, simplification of prober maintenance is an urgent issue.

Patent Literature 1 discloses a pogo block-shaped interface that is detachably attached with a plurality of pin units provided with contact pins (pogo pins) and is excellent in maintenance. However, since the mounting position of the interface to which a plurality of pin units is attached is a narrow space between the measurement stage and the test head, it is necessary to remove the test head in order to perform maintenance on the contact pins.

As for the removal of the test head, for example, a commercially available trolley with an elevator or an overhead crane is used to move the test head up and down for delivery. For example, Patent Literature 2 discloses a method of supporting the flange portion of the test head by a slide rail inside the inspection chamber and drawing it out to the maintenance space side.

As in Patent Document 2, when performing maintenance on the contact pins of the pogo frame by removing or pulling out the test head, a large change in weight occurs inside the prober. Restoration work such as confirmation of Restoration work other than maintenance may take two to three hours, which is a factor in prolonging the downtime of the prober.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a prober capable of simplifying maintenance of a pogo frame or the like and shortening downtime, and a maintenance method thereof.

In order to solve the above problems, a prober according to a first aspect of the present invention includes a wafer chuck that holds a wafer, a probe card that has a plurality of probes on a surface facing the wafer chuck, and a wafer chuck of the probe card. comprises a test head arranged on the opposite side, a pogo frame interposed between the probe card and the test head and electrically connecting the probe card and the test head, and a head stage holding the pogo frame. The pogo frame is configured to be pulled out to the maintenance area integrally with the head stage.

A prober according to a second aspect of the present invention, in the first aspect, has an integral structure of the pogo frame and the head stage.

A prober according to a third aspect of the present invention is the prober according to the first or second aspect, wherein the measurement section has a guide section for slidingly moving the head stage.

A prober according to a fourth aspect of the present invention is provided with a plurality of measurement units in any one of the first to third aspects.

A fifth aspect of the present invention is a maintenance method for a prober that inspects a wafer, comprising a step of raising a test head with respect to a pogo frame, and maintenance of the pogo frame integrated with a head stage holding the pogo frame. and drawing into the area.

According to the present invention, downtime of the prober after maintenance of the pogo frame can be suppressed.

FIG. 1 is a perspective view showing a prober according to one embodiment of the present invention. FIG. 2 is a front view showing the measuring section. FIG. 3 is a perspective view showing a test head. FIG. 4 is a perspective view showing how the test head is conveyed. FIG. 5 is a perspective view showing how the test head is conveyed. FIG. 6 is a front view showing the test head stand. FIG. 7 is a perspective view showing a test head stand. FIG. 8 is a front view showing the test head elevating mechanism of the measuring section. FIG. 9 is a perspective view for explaining the test head elevating mechanism. FIG. 10 is a perspective view for explaining the test head elevating mechanism. FIG. 11 is a front view for explaining the pogo frame lifting mechanism. FIG. 12 is a perspective view for explaining the pogo frame lifting mechanism. FIG. 13 is a perspective view showing an example in which the pogo frame lifting mechanism is omitted.

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of a prober and its maintenance method according to the present invention will be described below with reference to the accompanying drawings.

[Prober configuration]
FIG. 1 is a perspective view showing a prober according to one embodiment of the present invention.

As shown in FIG. 1, the prober 10 according to this embodiment includes a loader section 12 and a body section (measurement unit) 14 . The prober 10 is a multi-stage prober, and the main unit 14 includes a plurality of measurement units 16 (25 stages in the example shown in FIG. 1). The prober 10 also includes an operation panel and a control device (not shown) for controlling each part.

The loader section 12 includes a load port on which a wafer cassette containing wafers W to be inspected (see FIG. 2) is mounted, and a transfer unit for transferring the wafers W (both not shown). The wafer W is supplied to and recovered from each measurement unit 16 of 14 .

As shown in FIG. 1, the body portion 14 has a laminated structure (multi-stage structure) in which a plurality of measuring portions 16 are laminated in a multi-stage manner, and each measuring portion 16 is arranged in two directions along the X direction and the Z direction. Dimensionally arranged. The body portion 14 is configured by combining a plurality of frames in a grid pattern, and the space portion surrounded by these frames has a substantially rectangular parallelepiped shape. Components of the measurement unit 16 are arranged in this space.

In the main unit 14 , the electrical characteristics of the chips (semiconductor devices) formed on the wafer W are inspected (wafer level inspection) for the wafer W supplied from the loader unit 12 to each measuring unit 16 . The wafer W inspected by each measuring section 16 is recovered by the loader section 12 .

[Measurement part]
FIG. 2 is a front view showing the measuring section 16. As shown in FIG. In the following description, in order to avoid complication of the drawings, the reference numerals for the symmetrical structures may be omitted as appropriate.

Each measurement section 16 has the same configuration, and includes a wafer chuck 50, a probe card 54, and a head stage 58, as shown in FIG. Each measurement unit 16 is provided with a test head 18 . The test head 18 is supported above the head stage 58 (on the side opposite to the wafer chuck 50 with respect to the probe card 54) by a test head holding portion (not shown in FIG. 2; the guide 102 in FIG. 8).

The head stage 58 is supported by a frame member (not shown) forming part of the housing, and the pogo frame 56 is attached.

The pogo frame 56 is interposed between the test head 18 and the probe card 54 and has interfaces (contact pins) for electrically connecting the test head 18 and the probe card 54. The test head 18 and the probe card 54 are fixed to 56 by suction. The probe card 54 is provided so as to face the wafer holding surface 50 a of the wafer chuck 50 . The probe card 54 is replaced according to the wafer W (device) to be inspected.

The probe card 54 is provided with a plurality of probes 52 in the shape of cantilevers, spring pins, or the like arranged corresponding to the positions of the electrode pads of each chip of the wafer W to be inspected. Each probe 52 is electrically connected to a terminal of the test head 18, a power supply and a test signal are supplied from the test head 18 to each chip through each probe 52, and an output signal from each chip is detected by the test head 18. to see if it works properly.

The probe 52 has a spring characteristic, and by raising the contact point from the tip position of the probe 52, it contacts the electrode pad with a predetermined contact pressure.

The wafer chuck 50 holds the wafer W by vacuum suction. The wafer chuck 50 has a wafer holding surface 50a on which the wafer W to be inspected is placed, and the wafer holding surface 50a is provided with a plurality of suction ports (not shown). The suction port is connected to a suction device (vacuum source, such as a vacuum pump, an ejector, etc.) via a suction path (not shown) formed inside the wafer chuck 50 .

The wafer chuck 50 is detachably supported and fixed to the alignment device 70 . The alignment device 70 moves the wafer chuck 50 in the X, Y, Z, and θ directions to perform relative alignment between the wafer W held by the wafer chuck 50 and the probe card 54 .

The alignment device 70 is a Z stage (Z-axis moving/rotating unit) that detachably supports and fixes the wafer chuck 50, moves the wafer chuck 50 in the Z-axis direction, and rotates about the Z-axis in the θ direction. 72, an X carriage (X-axis moving table) 74 that supports the Z stage 72 and moves in the X-axis direction, and a Y carriage (Y-axis moving table) 76 that supports the X carriage 74 and moves in the Y-axis direction. It has The Z stage 72, X carriage 74, and Y carriage 76 include, for example, mechanical drive mechanisms including motors, and are configured to move the wafer chuck 50 in the ZXY directions. Furthermore, the Z stage 72 is configured to rotate the wafer chuck 50 in the .theta. direction around the rotation axis. The mechanical drive mechanism may be, for example, a ball screw drive mechanism combining a servomotor and a ball screw, a linear motor drive mechanism, a belt drive mechanism, or the like.

[Test head]
FIG. 3 is a perspective view showing the test head 18. As shown in FIG.

As shown in FIG. 3, the test head 18 has a substantially rectangular parallelepiped shape, and rail portions (flange portions) 18a are provided on the side surfaces thereof. The measurement section 16 is supported above the head stage 58 by supporting the rail section 18a with the test head holding section (the guide 102 in FIG. 8).

The rail portions 18 a are formed in a substantially rectangular parallelepiped shape projecting from the side surfaces of the test head 18 , and are provided on the side surfaces of the test head 18 . Note that the shape of the rail portion 18a is not limited to a substantially rectangular parallelepiped shape, and may be any shape that can slide on the guide 102, for example. Moreover, the rail portion 18 a may be formed integrally with the side surface of the test head 18 or may be formed by fixing another member to the side surface of the test head 18 .

4 and 5 are perspective views showing how the test head 18 is conveyed. As shown in FIGS. 4 and 5, the test head 18 can be lifted inside the measuring section 16 and slid along the rail section 18a. Thereby, it can be pulled out from the measuring section 16 or accommodated in the measuring section 16 .

FIG. 4 shows an example in which the test head 18 is transported by the carriage 30. As shown in FIG. The carriage 30 includes a test head stand 32 and an elevator for vertically moving the test head stand 32 up and down. In the example shown in FIG. 4 , the test head 18 of each measuring section 16 can be taken in and out by moving the carriage 30 and raising and lowering the test head table 32 to place it in front of the measuring section 16 . .

FIG. 5 shows an example of transporting the test head 18 by a crane 40. As shown in FIG. The crane 40 is connected, for example, to the ceiling of the place where the prober 10 is installed, and is capable of moving and raising and lowering the test head table 42 . In the example shown in FIG. 5 as well, the test head 18 of each measuring section 16 can be taken in and out by moving and raising and lowering the test head table 42 and arranging it in front of the measuring section 16 .

6 and 7 are a front view and a perspective view showing the test head stand. Since the test head stands 32 and 42 have the same configuration, an example of the test head stand 32 will be described below.

As shown in FIG. 6, the test head stand 32 is configured as a bottomed container with a U-shaped cross section that opens vertically upward. The test head pedestal 32 has a bottom wall and side walls, and is open in the direction in which the test head 18 is pulled out (the front-rear direction of the paper surface of FIG. 6). The test head table 32 has a substantially rectangular parallelepiped shape with a bottom surface and side walls. A rotating body 80 on the tire is attached to the inner side of the side wall of the test head stand 32 . By sliding the rail portion 18a of the test head 18 onto the rotor 80, the test head 18 can be drawn out toward the test head table 32 side. Here, a slide rail may be provided instead of the rotating body 80 .

Reference numeral 82 in FIGS. 6 and 7 denotes projections for positioning the test head 18 in the sliding direction, and the projections 82 define the sliding end position of the test head 18 . It should be noted that a projecting protrusion may be provided on the back side of the side wall of the test head table so that the sliding movement of the test head 18 during transportation can be restricted.

[Test head maintenance]
Next, a procedure for maintenance of the test head 18 will be described. In the present embodiment, maintenance of the test head 18 includes maintenance performed by pulling the test head 18 out of the measuring unit 16 (for example, internal adjustment), and raising the test head 18 with respect to the pogo frame 56 inside the measuring unit 16. It is possible to perform maintenance by

FIG. 8 is a front view showing the test head elevating mechanism of the measuring section 16, and FIGS. 9 and 10 are perspective views for explaining the test head elevating mechanism.

The test head elevating mechanism 100 includes a guide 102 and an elevating drive section 104 . The rail portion 18 a of the test head 18 is placed on this guide 102 . The guide 102 is formed in a plate shape extending in the sliding direction (Y direction) of the test head 18 .

The elevation drive unit 104 includes a drive unit for raising and lowering the guide 102 in the vertical direction (Z direction). Here, as the elevation drive unit 104, for example, a mechanism for performing reciprocating linear motion such as an air cylinder, a hydraulic cylinder, or a drive mechanism using a motor (for example, a ball screw mechanism, a rack and pinion mechanism) may be used. can be done.

When the test head 18 is pulled out from the measuring section 16, the lift driving section 104 (see FIG. 9) raises the guide 102 and separates it from the pogo frame 56, as shown in FIG. By pulling out the test head 18 from the measuring section 16, the rail section 18a slides from the guide 102 onto the side wall of the test head table (32 or 42). Thereby, the test head 18 can be pulled out from the measuring section 16 (see FIGS. 4 to 7). When the gap between the guide 102 and the test head pedestal (32, 42) is large, the guide 102 can be pulled out from the measuring unit 16, and the gap between the guide 102 and the test head pedestal (32, 42) can be adjusted. The gap between them may be made shortenable.

When the test head 18 is housed in the measuring section 16 , the test head table ( 32 or 42 ) on which the test head 18 is mounted is moved to the front of the measuring section 16 . Next, while the guide 102 is lifted by the elevation driving unit 104, the guide 102 is pulled out toward the test head mounting table (32 or 42), and the test head is moved toward the test head mounting table (32 or 42). 18 is slid. Then, the test head 18 is accommodated in the measuring section 16 and the guide 102 is lowered by the elevation driving section 104 . This allows the test head 18 to be connected to the pogo frame 56 .

Note that the guide 102 may also be provided with a rotator like the test head table (32 or 42).

In this embodiment, minor maintenance of the test head 18 can be performed while the test head 18 is lifted within the measurement unit 16 by the test head lifting mechanism 100 . Also, the adjustment of the inside of the test head 18 can be carried out by pulling it out of the measuring section 16 according to the above procedure.

[Pogo frame maintenance]
Next, maintenance of the pogo frame 56 will be described.

Part of the maintenance of the pogo frame 56 (contact pin) can also be performed with the test head 18 raised, for example, as shown in FIG. For example, a pogo frame having block-shaped contact pins divided into individual blocks, as disclosed in Patent Document 1, can be partially maintained even when the test head 18 shown in FIG. 8 is raised. is.

On the other hand, in a state in which the test head 18 is simply raised, it is difficult to ensure workability depending on the content of maintenance. For this reason, the prober 10 of the present embodiment includes a pogo frame lifting mechanism 200 for lifting and lowering the pogo frame 56 to pull it out to the maintenance area of the measurement unit 16 .

11 and 12 are a front view and a perspective view for explaining the pogo frame lifting mechanism 200. FIG.

As shown in FIGS. 11 and 12 , the pogo frame lifting mechanism 200 includes a guide 202 and a lifting drive section 204 .

The guide 202 is a guide rail configured to be slidable along the drawing direction (Y direction). The pogo frame 56 is fixed to this guide 202 via the mounting portion 56a.

The elevation driving section 204 includes a driving section for raising and lowering the guide 202 in the vertical direction (Z direction). Here, as the elevation drive unit 204, for example, a mechanism for performing reciprocating linear motion such as an air cylinder, a hydraulic cylinder, or a drive mechanism using a motor (for example, a ball screw mechanism, a rack and pinion mechanism) may be used. can be done.

When performing maintenance on the pogo frame 56, first, as shown in FIG. Next, as shown in FIG. 11, the pogo frame 56 is raised with respect to the head stage 58 by raising the guide 202 by the elevation drive section 204 (see FIG. 12). Then, the guide 202 is slid in the Y direction, and the pogo frame 56 is pulled out from the measuring section 16 . Maintenance of the pogo frame 56 may be performed by removing the pogo frame 56 from the guide 202 , or may be performed while the pogo frame 56 is pulled out and attached to the guide 202 . As a result, it is possible to secure the maintenance workability of the pogo frame 56 .

According to this embodiment, only by moving the test head 18 up and down within the measuring section 16, the contact pins can be pulled out together with the pogo frame 56 for maintenance. As a result, the weight of the test head 18 remains on the frame 90 during maintenance of the pogo frame 56 , so that a large weight change does not occur inside the prober 10 . For this reason, after maintenance of the pogo frame 56, there is no need to perform restoration work such as readjustment and confirmation of the diagnostic code, so downtime of the prober 10 can be suppressed.

In the present embodiment, the pogo frame 56 is moved up and down by the pogo frame lifting mechanism 200, and the pogo frame 56 is pulled out to the maintenance area of the measurement unit 16. As shown, the pogo frame 56 and the head stage 58 are integrally integrated into the measurement unit 16 by a guide unit 300 that slides the head stage 58 while the pogo frame 56 is mounted on the head stage 58 without raising or lowering the pogo frame 56 . It is possible to preferably employ a configuration in which the maintenance area A1 is drawn out. Also in this configuration, maintenance can be simplified and downtime can be shortened, as in the above-described embodiment. In addition, since a mechanism for lifting and lowering the pogo frame 56 from the head stage 58 is not required for maintenance of the pogo frame 56, it is possible to simplify the configuration and reduce costs. Moreover, if the pogo frame 56 and the head stage 58 can be pulled out integrally in this manner, the head stage 58 and the pogo frame 56 can be integrated.

DESCRIPTION OF SYMBOLS 10... Prober, 12... Loader part, 14... Main-body part (measurement unit), 16... Measurement part, 18... Test head, 50... Wafer chuck, 52... Probe, 54... Probe card, 56... Pogo frame, 58... Head Stage 70 Alignment device 72 Z stage 74 X carriage 76 Y carriage 100 Test head elevating mechanism 200 Pogo frame elevating mechanism 300 Guide section

Claims (5)

a wafer chuck that holds the wafer;
a probe card having a plurality of probes on a surface facing the wafer chuck;
a test head disposed on the opposite side of the probe card from the wafer chuck;
a pogo frame interposed between the probe card and the test head for electrically connecting the probe card and the test head;
a headstage holding the pogo frame;
comprising a measurement unit comprising
The pogo frame is configured to be pulled out to a maintenance area integrally with the head stage,
prober. wherein the pogo frame and the headstage are of unitary construction;
The prober according to claim 1. The measurement unit has a guide unit that slides the head stage.
The prober according to claim 1 or 2. comprising a plurality of the measuring units,
A prober according to any one of claims 1 to 3. A maintenance method for a prober that inspects a wafer, comprising:
raising the test head relative to the pogo frame;
pulling out the pogo frame together with a head stage holding the pogo frame to a maintenance area;
How to maintain the prober, including

Images