JPH06274215A - Work inspection device - Google Patents

Abstract

PURPOSE:To provide a work inspection device capable of accurately and quickly moving a work loaded on a chuck board to be moved to an optional position in X, Y and theta directions to an inspection position. CONSTITUTION:Plural works 100 stored in a work supplying cassette 22 are moved to a vacuum chuck board 21 by a transfer arm 23. Each work 100 is moved to a position opposed to a microscopic camera unit 70, the reference mark 100b of the work 100 is detected, an error between the reference mark 100b and an initialized work movement objective position is calculated and an initial correction value based upon the error is determined and stored. A drive control part 80b drives the chuck board 21 in each movement of the chuck board 21 based upon the initial correction value so that the reference mark of the work 100 coincides with a work movement objective position to correct the position of the work.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a work inspection device, and more particularly to a work inspection device for correcting the position of a work placed on a chuck table that is mechanically positioned.

[0002]

2. Description of the Related Art A prober is widely used to rapidly inspect devices such as IC wafers and liquid crystal display devices (hereinafter referred to as "workpieces"). Usually, a prober brings a probe (stylus) of a probe card into contact with an electrode pad of a work fixed to a substrate, and an inspection machine electrically connected to the probe card inspects between the electrode pads, for example, open / short, Alternatively, the electrical characteristics of the device are sequentially measured and inspected according to a predetermined program.

With such a prober, as the element arrangement of the work becomes finer, the time required for one measurement inspection increases, and this reduction has been desired. In particular, as the number of electrode pads has increased, various desired tests have been performed by bringing a probe into contact with an electrode pad many times with respect to one work. For this reason, there has been a demand that the relative movement between the probe card and the work must be performed quickly and reliably.

In a conventional work inspection device such as a prober,
Place the work on the work holder such as chuck table,
The workpiece was quickly moved to the inspection position by driving the workpiece by a predetermined amount in the X, Y and θ directions with respect to the probe card by the chuck table moving mechanism configured by combining the chuck table with a servo motor and a ball screw. .

[0005]

However, in the conventional workpiece inspection apparatus, when the workpiece is positioned and fixed on the chuck table, the workpiece is biased in a predetermined direction against the positioning pin or the wall surface provided on the chuck table. Later, it was carried out by a fixing means such as a fixing claw or vacuum suction. Therefore,
When the biasing force on the work is biased or foreign matter is caught between the work and the chuck table, the fixing condition is easily changed on the chuck table and the position of the work is changed. In other words, the chuck table itself on which the work is placed is accurately moved by the chuck table drive mechanism, but since the placement error between the chuck table and the work is not taken into consideration, the work is accurately moved to the inspection position. There was a problem that it could not be done.

Further, the pattern of the work is formed by printing, but even when the work is accurately placed and the chuck table is accurately moved due to print misalignment at the time of pattern formation, an electrode pad for inspecting the work is used. There is a problem that the probe cannot be accurately contacted.

Further, even if the placement error is detected at the inspection position and the placement error is eliminated by finely adjusting the X and Y directions, the conventional work inspection apparatus uses the probe card to perform the next inspection. It also moved in the θ direction.
Therefore, the amount of adjustment in the X and Y directions changes with each movement, and it is necessary to detect the placement error and perform the adjustment with each movement of the work, resulting in poor inspection efficiency.

The present invention has been made in view of the above conventional problems, and an object of the present invention is to accurately and quickly inspect a workpiece placed on a chuck table that moves to arbitrary positions in the X, Y and θ directions. It is an object of the present invention to provide an improved work inspection device that can be moved to the next position.

[0009]

In order to achieve the above object, the present invention provides a probe card having a probe for inspecting a work and a work placed on the probe card at arbitrary positions in the X, Y and θ directions. A chuck table that moves and positions the workpiece with respect to the probe card, removes the workpiece from the workpiece supply cassette, moves the workpiece to the chuck table for inspection with the probe card, and also removes the workpiece after the inspection from the chuck table. A transfer arm for moving to the work discharge cassette, a mark detection unit for detecting the position of the reference mark attached to the work, and an error between the reference mark detected by the mark detection unit and the initially set work movement target position. And a calculation storage unit that stores an initial correction value based on the error, and an initial correction stored in the calculation storage unit. Based on the above, each time the chuck table is moved for inspection, a drive control section that drives the chuck table so as to match the reference mark position of the work with the work movement target position at each movement position is provided. It is a feature.

[0010]

Therefore, according to the present invention, a plurality of works such as IC wafers or liquid crystal display elements are pre-packaged in the supply cassette, and the work inspection device automatically transfers the works one by one from the work supply cassette. It is placed on the chuck table and moved to a position facing the mark detection unit. The mark detection unit detects a reference mark attached to a predetermined position of the work, and based on the reference mark position and the work movement target position preprogrammed in the work inspection device in the calculation storage unit, the mark detection unit moves the work piece on the chuck table. The placement error is calculated and the initial correction value is determined and stored. Every time the chuck table on which the work is placed moves to a position facing the probe card, the drive controller corrects an error based on the initial correction value so that the reference mark position and the work movement target position match. The table is driven to correct the position, and the probe is brought into contact with the correct position on the workpiece to perform the desired inspection.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a structural explanatory view for realizing a preferred embodiment of the work inspection apparatus according to the present invention. The main body base frame 10 is provided with two pairs of probe cards. The open / short inspection in the X-axis direction (hereinafter, simply referred to as inspection) is performed by the X1 probe card 11 and the X2 probe card.
The pair of probe cards 12 is used, while the inspection in the Y-axis direction is performed by the pair of Y1 probe card 13 and Y2 probe card 14. These probe cards 11, 12, 13, 14 are made of an insulating substrate having a printed wiring on the surface, and a plurality of probes (stylus) 11a, 12a, 1 are provided in an opening provided at the substantially center thereof.
3a and 14a are mounted, and as is well known, the tip of the IC
It is possible to contact the electrode pad of the work 100 such as a wafer or a liquid crystal display element. Each probe card 11, 12,
Reference numerals 13 and 14 are detachably fixed to an X1 stage 15, an X2 stage 16, a Y1 stage 17, and a Y2 stage 18, respectively, and a probe card having a desired shape can be selectively used according to the work 100. X1
The stage 15 and the Y1 stage 17 are fixed to the base frame 10 at substantially predetermined positions, but the X2 stage 16 and the Y2 stage 18 are respectively provided with rails 19 relative to the base frame 10.
It is possible to travel on and 20 and the measurement intervals in the X-axis and Y-axis directions can be arbitrarily adjusted according to the work 100.

On the other hand, as shown in FIG. 2, a substantially cross-shaped reference mark 100b is printed on the surface of the work 100 at a position separated from the electrode pad 100a by a predetermined distance in the X and Y directions. The reference mark 100b is printed at the same time when the pattern wiring is printed, and the work 100 is positioned according to the reference mark 100b.

Further, as shown in FIG. 1, the reference mark 1 is provided between the X1 stage 15 and the Y1 stage 17.
The microscope camera unit 70 is fixed as a mark detection unit for detecting 00b.

A vacuum chuck base 21 is provided on the main body base frame 10 so as to be movable in X, Y and θ directions.
The work 100 is fixedly held by the vacuum chuck table 21 and can be moved to a position facing the microscope camera unit 70 and the probes 11a, 12a and 13a, 14a. The vacuum chuck base 21 shown by the solid line in FIG. 1 shows the position where the work is taken out from the work supply cassette 22, and when the vacuum chuck base 21 is moved to the position of the chain line 21-1, the microscope camera unit 70 detects the work Position detection can be performed. Move from this position to the right in the figure and move to the dashed line 21-2.
When it is moved to, it is possible to inspect the work in the Y-axis direction by the Y-axis probe cards 13 and 14, and rotate 90 ° from this direction and move to the left in the figure to move the broken line 2
When moved to the 1-3 position, the probe card 1 in the X-axis direction
It is possible to perform measurement and inspection in the X-axis direction using 1 and 12. In addition, the vacuum chuck base 21 is again replaced by the solid line 21.
When the work is moved to the position of, the work is taken in from the work supply cassette to the vacuum chuck table 21 and is discharged to the work discharge cassette from the vacuum chuck table 21 as described later.

A work supply cassette 22 accommodating a plurality of works is mounted in the main body base frame 10, as shown in FIG.
In the work supply cassette 22, a plurality of works 100 indicated by chain lines are stacked and stored.
Further, in the illustrated embodiment, the work discharge cassettes are stacked and fixed below the work supply cassette 22, and both cassettes are simultaneously moved up and down by an elevator mechanism, which will be described later, to move the work supply cassette 22 to a predetermined position. The work 100 is taken out to the vacuum chuck base 21, and the work 100 is stored and discharged from the vacuum chuck base 21 to a predetermined position of the work discharge cassette.

A transfer arm 23 is provided to take out the work 100 from the work supply cassette 22 to the vacuum chuck table 21. The transfer arm 23 is inserted into the gap between the works 100 arranged in a stack, and the work 100 is transferred to this arm. A desired work 100 can be taken out from the work supply cassette 22 by placing it on the work piece 23. For this purpose, the transfer arm 23 has a base portion 23a supported on a guide rail 24 so as to be movable in the left-right direction in FIG. 1, and a feed belt 25 having one end fixed to the transfer arm base portion 23a is provided with an arm feed motor 26. The transfer arm 23 can be moved in either direction by this to move the transfer arm 23 into the work supply cassette 22 as shown by the chain line, and the work 100 can be taken out to the vacuum chuck table 21 as described above. In FIG. 1, the main body base frame 10 may be provided with an attached work discharge cassette 27 in parallel with the work supply cassette 22. For example, the work discharge cassette can be divided into three types, that is, a non-defective product, a defective product, and a partially repaired product, according to the inspection result, and can be discharged to each work discharge cassette.

FIG. 3 shows the vacuum chuck base 2 described above.
The X, Y and θ movement mechanisms of 1 are shown. An X board 30 is fixed to the main body base frame 10, and a Y board 31 is movably mounted in the X axis direction on two X rails 30a and 30b provided on the X board 30. In addition, the Y board 31 on the Y board 31 has a θ board 32
Is movably mounted in the Y direction. And this θ
A chuck lower plate 43 is rotatably supported on the substrate 32.

Therefore, the vacuum chuck base 21 can be moved to an arbitrary position at an arbitrary angle by an X motor, a Y motor and a θ motor (not shown).

FIG. 4 shows the work supply cassette 2 described above.
2 and the elevating mechanism of the work discharge cassette 35 which is stacked and arranged below this. Work supply cassette 2
2 is a tray 36, and the work discharge cassette 35 is a tray 36
It is placed on the tray ′, and lifting nuts 37 are fixed to the trays 36 and 36 ′. An elevating screw 38 screwed into the elevating nut 37 is rotatably supported by the main body base frame 10. The driving force of the lifting motor 39 fixed to the main body base frame 10 is applied to the lifting screw 3 via the belt 40.
8, and both cassettes 22 and 35 can move up and down via the lifting nut 37 according to the rotation of the lifting screw 38. Therefore, the transfer arm 23 has the height of the work 10 determined by the lifting mechanism shown in FIG.
0 is taken out to the vacuum chuck table 21 described above, and the work discharge cassette 3 defined by the elevating mechanism.
The work 100 can be stored in the unit 5.

FIG. 5 shows a plan view of the vacuum chuck base 21. The vacuum chuck base 21 itself is made of a lightweight metal such as aluminum and has a plurality of vacuum grooves 21a on its surface. And
Communication passage 2 provided inside the vacuum chuck base 21
Pressurized air or suction pressure is supplied from 1b to each groove 21a to one or two openings 21c.
Of course, such a vacuum groove 21a can be formed by a simple vacuum hole instead of the long groove as shown. In the illustrated embodiment, all the vacuum holes 21a are communicated with each other by the communication holes 21b, and the communication end 21d thereof.
An external fluid connector can be joined to the desired pressure air or suction pressure to connect to each vacuum groove 21a.

The vacuum chuck table 21 as described above is
The workpiece 100 supplied from the above-mentioned transfer arm 23 is received on the workpiece mounting surface 21e, and at the time of positioning with respect to the vacuum chuck base 21, pressurized air is supplied to the vacuum groove 21a to supply the vacuum chuck base 21. Air bearing action between the workpiece and the work 100, and the work 100 is freely slid,
It can be moved to a desired position. On the other hand, after the placement of the work 100 is completed in this way, the work 100 is placed on the vacuum chuck table 2 at the selected position.
A suction pressure is supplied to each vacuum groove 21a in order to fix the workpiece 100 on the workpiece mounting surface 21e, so that the workpiece 100 can be securely sucked onto the vacuum chuck table 21 and its position can be held and fixed. it can.

On the upper surface of the vacuum chuck base 21, a plurality of reference positioning pins 42a, in the embodiment, five reference positioning pins 42a are provided.
To 42e are provided, and these reference positioning pins 42 are used as the work placement surface 21e of the vacuum chuck base 21.
It projects further upward, and is provided so that it can be pushed into the vacuum chuck base 21 as required. Therefore, the user can arbitrarily select these five reference positioning pins 42 and select the position according to the work shape.

The work 100 is placed at a desired position on the vacuum chuck base 21 by being brought into contact with the positioning pin 42 thus selected, and is moved to a position facing the above-mentioned probe card. At this time, according to this embodiment, a mechanism for pressing the work 100 against each of the positioning pins 42 described above is provided on the chuck lower plate 43 of the vacuum chuck base 21.

6 and 7 show a work slide mechanism provided on the lower chuck plate 43, which includes an X air cylinder 44 and a Y air cylinder 45 fixed to the lower chuck plate 43. , 45 movable heads 44
An X push pin 48 and a Y push pin 49 are fixed to a and 45a via links 46 and 47, respectively. The push pins 48. are inserted into the slits 21f and 21g provided in the vacuum chuck base 21 shown in FIG.
49 enters and the work 10 is made by both pins 48 and 49.
It is possible to reliably press and hold 0 toward the desired positioning pin 42.

When the workpiece 100 is positioned and slid, pressurized air is supplied to each vacuum groove 21a, and the workpiece mounting surface 21e of the vacuum chuck table 21 is supplied.
Between the workpiece 100 and the work 100, thereby causing no damage to the work 100,
The positioning operation can be performed reliably and quickly.
When the work 100 is moved onto the vacuum chuck table 21 by the transfer arm 23, in order to reliably land the work 100 on the vacuum chuck table 21 from the transfer arm 23 via the air bearing,
A landing cylinder 50 is provided on the lower chuck plate 43, and the landing mechanism is shown in FIG. The landing cylinder 50 includes landing guides 51, 5 for the chuck lower plate 43.
A landing frame 53 slidably supported in the up-down direction is supported on the land 2 so as to be vertically movable. Two landing suction cups 54a, 54a are provided on landing bars 54, 55 provided at both ends of the landing frame 53, respectively. 54b and 55a, 55b
Is fixed, and each landing suction cup 54a, 54b, 55a, 55
b is a vacuum chuck base 21 as shown in FIG.
Can be projected onto the workpiece mounting surface 21e.

Therefore, as shown in FIG. 9, landing suction cups 54a, 54b and 55a, 55b (landing suction cup 54
(b and 55b are not shown) are normally retracted and housed inside the vacuum chuck base 21, but when the work 100 is moved above the vacuum chuck base 21 by the transfer arm 23, it is illustrated. The landing cylinder 50 is actuated by the non-sequence controller, and as shown by the chain line in FIG.
54a and 54b rise and receive the work 100 from the transfer arm 23 to the vacuum chuck table 21 side. Then, when the transfer arm 23 retracts from the vacuum chuck base 21 in this state, the landing suction cups 54a and 55a are again housed in the vacuum chuck base 21 as shown by the solid line in FIG. Since the pressurized air is ejected from each vacuum groove 21a, the work 100 can freely move on the vacuum chuck table 21 by the air bearing action. Then, in this state, the work 100 having the air bearings for the work push pins 48 and 49 shown in FIGS. 6 and 7 can be easily pressed against the reference pin.

When the work 100 is positioned on the vacuum chuck base 21 in this way, suction pressure is supplied to each vacuum groove 21a instead of the pressurized air until then, and as a result, the work 100 is finished. Will be securely suction-fixed and held on the vacuum chuck base 21.

The workpiece 100 sucked and held in this way can be subjected to a predetermined inspection by the X and Y axis probe cards as shown in FIG. 1 by the movement of the vacuum chuck table 21.

The work position correcting operation of the work inspection apparatus configured as described above will be described below with reference to FIGS. 1 and 10.

A vacuum chuck base 21 on which the work 100 taken out from the work supply cassette 22 is fixedly mounted.
Is first moved to a position immediately below the microscope camera unit 70, that is, to a position indicated by a broken line 21-1 in FIG. 1 by the moving mechanism described above. At this time, the vacuum chuck base 21 is moved by a distance programmed in advance by the moving mechanism described above. When the movement by the program is completed, the microscope camera unit 70 reads the image of the substantially cross-shaped reference mark 100b printed at a predetermined position of the work 100 and sends the image of the reference mark 100b to the control unit 80. The fiducial mark 100b read by the control unit 80 is subjected to image processing such as binarization processing, and at the microscope camera unit position initialized in the binarized data and the computation storage unit 80a in the computation storage unit 80a. Based on the workpiece movement target position 110, the amount of rotational deviation of the electrode pad 100a group of the workpiece 100 with respect to the Y axis of the workpiece movement target position, that is, θ = θ ₁ , and the rotational deviation of the workpiece 100 is eliminated, and the X and Y directions afterward are eliminated. Horizontal and vertical error amount of X = X ₁ ,
Y = Y ₁ is calculated and stored as an initial correction value.

Next, the vacuum chuck table 21 moves to the inspection position in the Y-axis direction preprogrammed by the above-mentioned moving mechanism, that is, the position 21-2 in FIG. 1 (Y-axis inspection initial position). At this time, the vacuum chuck table 21
Has a placement error consisting of θ = θ ₁ , X = X ₁ , and Y = Y ₁ even with respect to the workpiece movement target position at the inspection position in the Y-axis direction regardless of the placement error. is doing.

The drive control unit 80b of the control unit 80 outputs a Y-axis inspection correction command to the moving mechanism based on the initial correction value stored in the arithmetic storage unit 80a to inspect the workpiece 100 for Y-axis. Position correction is performed on the initial position.
First, the vacuum chuck base 21 is rotated by θ = θ ₁ by the θ-direction moving mechanism to rotate the workpiece 100 with respect to the Y-axis.
The amount of rotation deviation of the electrode pad 100a group is corrected. Next, the vacuum chuck table 21 is moved by X = X ₁ and Y = Y ₁ by the X and Y direction moving mechanism to move the workpiece 100.
Is accurately moved to the target movement position in the Y-axis direction. afterwards,
A desired inspection in the Y-axis direction is performed based on a predetermined inspection program. After the inspection in the Y-axis direction is completed, the vacuum chuck table 21 is returned to the Y-axis inspection initial position by the θ, X, Y moving mechanism, and then the vacuum chuck table 21 is moved to the inspection position in the X-axis direction. 21 is rotated 90 ° by the θ-direction moving mechanism, and vertically and horizontally moved by the X, Y moving mechanism. That is, 21-3 in FIG.
Position (X-axis inspection initial position). In this case as well, the vacuum chuck table 21 moves from the Y-axis inspection initial position by a predetermined amount according to a predetermined program, and therefore has a placement error with respect to the workpiece movement target position at the inspection position in the X-axis direction. Therefore, the drive controller 80b of the controller 80
Outputs an X-axis inspection correction command to the moving mechanism on the basis of the initial correction value stored in the arithmetic storage unit 80a to perform position correction on the X-axis inspection initial position of the work 100. First, the vacuum chuck base 21 is rotated by θ = θ ₁ by the θ-direction moving mechanism to correct the rotational deviation amount of the electrode pad 100a group of the work 100 with respect to the X axis. Next, the vacuum chuck table 21 is moved by X = Y ₁ and Y = −X ₁ by the X- and Y-direction moving mechanism to accurately move the work 100 to the target moving position in the Y-axis direction.
After that, a desired inspection in the Y-axis direction is performed based on a predetermined inspection program.

Then, the work 100 which has been inspected is
As described above, the product is sorted into good products or defective products according to the inspection result and discharged into the discharge cassette.

As described above, according to the present embodiment, the position correction at each inspection position can be carried out based on the initial correction value initially measured and calculated by the series of automated systems. The workpiece 100 can be quickly positioned at the correct position, and the desired inspection can be performed by the probe card.

In the embodiment shown in FIG. 5, the metal plates 61 and 62 used for the continuity test of the probe are fixed to the work mounting surface 21e of the vacuum chuck base 21 at the ends thereof, if necessary. Therefore, the continuity test of each probe can be performed. That is, when conducting such a continuity test, the probe is attached to one of the metal plates 6
1, 62, which allows the inspector to measure the contact resistance of the probe.

Further, as is apparent from FIG. 5, ceramic polishing plates 63 and 64 are provided at the other end of the vacuum chuck base 21, and the tip of the probe is periodically fixed to the ceramic polishing plates 63 and 64. It is possible to push it up and reproduce the contact resistance of the probe tip.

Further, although FIG. 2 shows an example in which the substantially cruciform reference mark 100b is provided at one predetermined place of the work 100, the present invention is not limited to this, and for example,
It may have any shape (circular, triangular, etc.). The marking method of the reference mark 100 is not limited to printing, and the same effect can be obtained by engraving or sputtering. Furthermore, by providing two or more reference marks and detecting the plurality of reference marks to correct the position, the error in the rotation direction of the work 100 can be specified more accurately.

Further, in this embodiment, in order to explain the operation in order, after the inspection in the Y-axis direction is completed, the vacuum chuck base 21 is returned to the Y-axis inspection initial position by the θ, X, Y moving mechanism, and then the X-axis inspection is started. Although it was moved to perform the inspection in the axial direction, the controller 80 calculates the initial correction value and the target movement position of the workpiece in the X-axis direction, and after the inspection in the Y-axis direction is completed, the vacuum chuck table 21 is directly moved to the X-axis. You may move to the workpiece | work movement target position of a direction.

[0040]

As described above, according to the present invention,
It becomes possible to inspect a work having a large number of electrodes such as an IC wafer or a liquid crystal display device automatically in a fully automatic manner very simply, quickly and accurately.

[Brief description of drawings]

FIG. 1 is a configuration explanatory view for realizing a preferred embodiment of a work inspection device according to the present invention.

FIG. 2 is a plan view showing a preferred embodiment of a reference mark attached to a work in this embodiment.

FIG. 3 is a view of X of a vacuum chuck base in this embodiment,
It is a schematic side view which shows the moving mechanism to a Y and (theta) direction.

FIG. 4 is an explanatory view showing an elevating mechanism for a work supply cassette and a work ejection cassette in the present embodiment.

FIG. 5 is a plan view showing a preferred embodiment of the vacuum chuck base in this embodiment.

FIG. 6 is an explanatory view showing a drive mechanism of a work push pin provided on the chuck lower plate of the vacuum chuck base in the present embodiment.

FIG. 7 is a side view of an essential part showing one of the work push pins shown in FIG.

FIG. 8 is a plan view showing a workpiece landing mechanism provided on the chuck lower plate in the present embodiment.

FIG. 9 is a cross-sectional view of a main part of the work landing mechanism in the present embodiment.

FIG. 10 is a plan view for explaining work position correction in the present embodiment.

[Explanation of symbols]

 10 Main body base frame 11, 12, 13, 14 Probe card 11a, 12a, 13a, 14a Probe 21 Vacuum chuck stand 21a Vacuum groove 22 Work supply cassette 23 Transfer arm 35 Work discharge cassette 70 Microscope camera unit (mark detection unit) 80 Control Part 80a arithmetic storage part 80b drive control part 100 work 100b fiducial mark

Claims (1)

[Claims] 1. A probe card having a probe for inspecting a work, a chuck table for placing the work, moving it to arbitrary positions in X, Y and θ directions, and positioning the work with respect to the probe card. A transfer arm for removing the work from the work supply cassette, moving the work to the chuck base for inspection by the probe card, and moving the post-inspection work from the chuck base to the work discharge cassette, and attached to the work. A mark detection unit that detects the position of the reference mark, and an operation memory that calculates an error between the reference mark detected by the mark detection unit and the initially set work movement target position, and stores an initial correction value based on the error. Section and the initial correction value stored in the calculation storage section, every time the chuck table moves for inspection. Workpiece inspection apparatus characterized by having a drive control unit for driving the chuck table so as to match the workpiece movement target position in the reference mark position and the movement position of the workpiece.