JPH11204622A - Positioning apparatus and method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable position correction or observation of a work member, even when a temporary positioning accuracy of the work member is rough and enable enhanced improvement of an apparatus operating efficiency, by acquiring position information with use of a mark other than a reference mark as a reference, even when the reference mark is out of the visual field of an image pick-up means. SOLUTION: When the position of a reference mark 25 on a scaler is located out of a view field of an image pick-up CCD, the position of the auxiliary mark 25 is found for calculating a relative position (X1 ', Y1 ') (steps S25 and S28). On the basis of this calculated result, a relative position (X1 , Y1 ) with respect to the reference mark 25 is found (steps S26 and S29).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for detecting a position of a work member with respect to a base member and aligning the work member with the base member, and a control method therefor.

[0002]

2. Description of the Related Art As a method of aligning a plurality of semiconductor chips of about 10 mm square with a base member made of aluminum or the like, a reference mark is attached to a scale fixed to the base member as shown in FIG. The present applicant has already proposed a method of detecting the relative position information between the reference mark and the semiconductor chip by an image processing apparatus and thereby aligning the semiconductor chip with high accuracy.

[0003]

However, in this method, it is necessary to always take the reference mark and the characteristic portion of the chip before and after the position correction into the same field of view of the CCD camera. As shown in FIG. 7B, if the correction amount is too large, there is a problem that the reference mark deviates from the field of view and positioning cannot be performed with high accuracy.

An object of the present invention is to enable high-precision positioning without fail even if the provisional positioning accuracy of a workpiece is low, and to improve the operability of the apparatus.

[0005]

In order to solve this problem, a positioning device according to the present invention has the following arrangement. That is, on a base member mounted on a stage, a reference mark provided on the stage and a predetermined work member are imaged by predetermined imaging means, and the reference mark and the work member in the obtained captured image are obtained. A positioning device for positioning said work member in accordance with a position, wherein said reference mark and an auxiliary mark provided in the vicinity of said reference mark are provided on said stage, said image being taken by said imaging means. Judging means for judging whether or not the fiducial mark is present in the video, and, when judging means judges that the fiducial mark is within the field of view, the relative position between the fiducial mark and the work member Alignment control is performed based on the position, and when it is determined that the reference mark does not exist by the determination unit, the auxiliary mark in the video is used and the outside of the field of view is used. And a control means for calculating quasi mark position and the relative position of the workpiece member, aligned on the basis of the calculated relative position.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A work positioning method according to the present invention will be described below with reference to the accompanying drawings, in which an embodiment is applied to an apparatus for bonding a chip to a base member.

In the embodiment, in the manufacture of an ink jet head having a base plate and a plurality of heater boards arranged in close contact with the base plate, the base plate is mounted on an X stage and the heater boards are sequentially positioned. An example will be described.

FIG. 1 is a schematic view of the configuration of a bonding apparatus according to an embodiment. A finger 3 holding a chip (heater board) 1 can be moved by a Y stage 5 and a Z stage 6 and a θ stage 4 And the base member (base plate) 2 can be moved by the X stage 9, and the X stage 9, Y
The stage 5 and the Z stage 6 are arranged in directions orthogonal to each other.

The scale 7 is mounted on the X stage 9 and is movable together with the base member. Reference marks 25, 25a and 26, which will be described later, are written on the upper surface of the scale 7, and the fixed CCD camera 10, The chip 1 and the scale 7 are arranged so as to be included in one field of view by 11 (having lenses 19 and 20 respectively).

Further, the control device 14 includes an image processing device 15,
16, the Y stage 5, the θ stage 4, and the X stage 9 are obtained from the reference marks 25, 26 and the position information of the chip 1.
When the positioning is performed, the Z stage 6 is controlled, and the chip 1 is attached to the base member 2. Each of the image processing devices 15 and 16 recognizes a corner position of a chip and a mark position to be described later in the images captured by the CCD cameras 10 and 11, and notifies the control device 14 of the result via the communication interface 8. .

FIG. 2 shows an example of an image picked up by the CCD cameras 10 and 11. In the figure, the values of X0 and Y0 are determined by the reference marks (25, 26) of the kale 7, and are measured and stored in advance.
In the case of the present embodiment, the relative position information Xpitch and the value of Y00 between the mark 25 and the mark 25a immediately next to the mark 25 are also measured in advance and stored.

In the above configuration, the chip 1 is bonded to a predetermined position on the base member 2 mounted on the X stage. The chip position when the finger 3 holds the chip 1 Therefore, if the position of the X stage is corrected according to the chip, the mark 25 or mark 26 which should be the reference may be out of the imaging visual field range, and the chip 1 cannot be bonded.

Therefore, in the present embodiment, when the mark 25 is out of the field of view, alignment is performed using the mark 25a instead. As a result, the allowable range for the movement of the X stage can be made large, and the position can be determined with high accuracy.

Hereinafter, description will be given along the steps of the control flow of FIG. It should be noted that the program based on the flowchart is stored in a memory in the control device 14 in advance. Of course, this program may be externally incorporated into the control device via a storage medium such as a floppy disk.

First, in step S1, the finger 1 is moved to a position where the CCD 1 and the CCD cameras 11 are in focus.
Move in the direction.

Next, at steps S2 and S3, the controller 14
Sends instructions to the image processing devices 15 and 16 to cause the image processing devices 15 and 16 to calculate X1, Y1, X2, and Y2, and to send the position information back to the control device 14. Steps S2 and S3 are the most characteristic features of the present invention, and will be described in more detail later.

In step S4, a deviation amount Δ of the θ stage
Calculate θ. This means that Δθ = arctan ((Y0−Y1 + Y2) / (X0−
X1 + X2)).

In step S5, it is compared whether the value of Δθ is within a predetermined angle range (permissible range) set in advance. If NO, a correction operation is performed on the θ stage 4 in step S6, and step S6 is performed again. It returns to S2 and step S3.

On the other hand, if the decision result in the step S5 is YES
If so, in step S7, the movement amounts ΔX and ΔY of the X stage 9 and the Y stage 5 are calculated. Here, the position of the corner C1 of the chip is set to (X10,
When positioning at Y10), ΔX and ΔY can be calculated as follows: ΔX = X10−X1 ΔY = Y10−Y1. In step S8, the obtained ΔX and ΔY are
It is determined whether the values are within the predetermined value range. If NO, the X stage 9 and the Y stage 5 are corrected in step S9, and the process returns to steps S2 and S3 for confirmation again. YE
If S, the finger 3 is lowered by the Z stage 6 to the position of the base member 2 in step S10, and
At step 11, the chip 1 is adhered to the base member 2, and at step S1
In step 2, only the finger 3 is raised to end a series of operations.

Each time the X stage 9 is moved at a constant pitch, the above-described series of operations are performed again, so that a plurality of chips can be stuck to the base member 2 with high accuracy.

Next, the steps S2 and S3 will be described in more detail. Since the steps S2 and S3 are basically the same, only the step S2 will be described here and the description of the step S3 will be omitted.

FIG. 4 is a flowchart showing step S2 of FIG. 3 in more detail.

First, in step S20, the position of the mark 25 to be a reference in the image visual field is predicted.

This position is estimated by measuring and storing the previous command position Xref0 of the stage and the approximate position Xd0 of the mark in the image field at that time. That is, feedback is provided for each stage.

As a result, assuming that the stage command position at the time of the actual correction operation is Xref, the mark position Xd in the image visual field at that time can be calculated as Xd = Xd0 + (Xref-Xref0).

In step S21, an image is captured.
In step S22, the detection range of the reference mark 25 is calculated. In the calculation, the width (Xa, Ya) of the detection range is set in advance so that Xa> (X direction mark size + stage absolute positioning error × 2) Ya> (Y direction mark size + maximum fluctuation width of the mark). X within the image field of view
The direction detection range is from (Xd-Xa / 2) to (Xd
+ Xa / 2) (FIG. 5).

In the configuration of the present embodiment, since the position of the mark in the Y direction hardly changes, the detection range is fixed in the Y direction.

In step S23, it is determined whether or not the detection range obtained in step S22 is unsuitable for mark position detection.

That is, if the detection range is entirely within the image visual field, the process proceeds to step S30. If the detection range is shifted to the left of the image visual field and a part is out of the visual field left end (= 0), steps S24 to S26 are performed. Execute Conversely, if a part of the view is shifted to the right and deviates from the right end of the visual field (= Xccd), steps S27 to S29 are executed.

If it is determined that the position exceeds the left end of the field of view, the process proceeds to step S24, and the right side of the detection range obtained in step S24 is calculated by the pitch Xpitch as shown in FIG.

That is, the detection range is defined as (Xd-Xa / 2 +
(X pitch) to (Xd + Xa / 2 + X pitch).

By doing so, step S25 is performed.
Then, the position of the auxiliary mark 25a on the right side is obtained.

In the scale 7 used in the present embodiment, the deviation between the mark 25 and the mark 25a in the Y direction is made sufficiently small, so that Y1 remains unchanged.

Next, in step S26, the corner point C1 of the chip 1 is detected, and the relative position (X1 ', Y1') of the corner point C1 with respect to the mark 25a is obtained. X1, Y1) are calculated.

This principle will be described with reference to FIG. The right direction in the figure is the positive direction of the X axis, and the upward direction is the positive direction of the Y axis.

Finally, since it is sufficient to correct the corner point C1 of the chip 1 to the position of the illustrated target position C0, the controller 14 informs the controller 14 of the chip 1 with respect to the mark 25 outside the field of view. What is necessary is just to output the current relative position of the corner point C1. That is, X1 and Y1 shown in the figure may be calculated.

Therefore, X1 and Y1 can be obtained by X1 = X1 '+ Xpitch Y1 = Y1'-Y00 (X1' is attached with a sign (negative value in the case shown))
It has become). Here, Xpitch and Y00 are known as described above.

The controller 14 receives the result and controls each stage according to the difference from the target position C0.

If it is shifted to the right, step S
Steps S27 to S29 are the same as steps S24 to S26, and a description thereof will be omitted.

The above is a description of S2.
Is omitted.

As described above, according to the present embodiment, the amount of the chip 1 to be corrected can be detected even when the reference mark 25 is out of the field of view of the image. That is, chip 1
Can be surely corrected even if the position is greatly shifted.

In the embodiment, the example in which the image processing device and the control device are separate has been described, but they may be integrated. The auxiliary mark 25a is CC
Although provided at the position displayed on the D camera 10 side, it may be provided on the CCD camera 11 side or on both sides. In addition, in order for at least one mark to be present in the field of view, it is desirable that the distance between the mark 25 and the mark 25a be smaller than the width of the field of view. Of course, it is desirable that the marks 25 a be provided on both sides of the mark 25.

Further, if the marks 25, 25a, 26, etc. have different colors, it is easy to determine which mark is in the field of view, so that the processing is simplified and the convenience is improved. good.

Further, an object of the present invention is to provide a storage medium storing a program code of software for realizing the functions of the above-described embodiments to a system or an apparatus, and to provide a computer (or CPU) of the system or apparatus.
And MPU) read and execute the program code stored in the storage medium.

In this case, the program code itself read from the storage medium realizes the functions of the above-described embodiment, and the storage medium storing the program code constitutes the present invention.

As a storage medium for supplying the program code, for example, a floppy disk, hard disk, optical disk, magneto-optical disk, CD-ROM, CD
-R, a magnetic tape, a nonvolatile memory card, a ROM, or the like can be used.

When the computer executes the readout program code, not only the functions of the above-described embodiment are realized, but also the OS (Operating System) running on the computer based on the instruction of the program code. ) May perform some or all of the actual processing, and the processing may realize the functions of the above-described embodiments.

Further, after the program code read from the storage medium is written into a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer, based on the instructions of the program code, It goes without saying that the CPU included in the function expansion board or the function expansion unit performs part or all of the actual processing, and the processing realizes the functions of the above-described embodiments.

[0049]

As described above, according to the present invention,
Even when the reference mark is out of the field of view of the imaging means, the position information is obtained based on another mark. Therefore, even if the accuracy of the temporary positioning of the work member is low, the position correction or the position of the work member is not performed. Confirmation can be made, and the operation rate of the device can be greatly improved.

[0050]

[Brief description of the drawings]

FIG. 1 is a block diagram of a chip sticking apparatus according to an embodiment.

FIG. 2 is a diagram illustrating a captured image and an operation principle in the embodiment.

FIG. 3 is a flowchart illustrating an operation processing procedure in the embodiment.

FIG. 4 is a flowchart showing operation processing contents in step S2 in FIG. 3;

FIG. 5 is a diagram for explaining the operation principle of FIG. 4;

FIG. 6 is a diagram illustrating a method for calculating a relative position of a corner point C1 of the chip 1 in the mark 25.

FIG. 7 is a diagram for explaining a conventional problem.

Claims (4)

[Claims] 1. A base member mounted on a stage,
A reference mark provided on the stage and a predetermined work member are imaged by predetermined imaging means, and the reference mark in the obtained captured image is aligned with the work member in accordance with the position of the work member. An apparatus, wherein the reference mark and an auxiliary mark provided in the vicinity of the reference mark are provided on the stage, and it is determined whether or not the reference mark exists in a video imaged by the imaging unit. Determining means for determining whether or not the reference mark is within the field of view, and performing positioning control based on the position of the reference mark and the relative position of the work member; If it is determined that the reference mark does not exist, the position of the reference mark outside the field of view and the relative position of the work member are calculated using the auxiliary mark in the image. And a control unit for performing positioning based on the calculated and calculated relative position. 2. The method according to claim 1, wherein the work member has a rectangular shape, and the control means rotates, rotates, and adjusts a position of a corner point of the work member.
2. The method according to claim 1, wherein the correction is adjusted by moving.
Item 5. The positioning device according to Item 1. 3. The alignment apparatus according to claim 1, wherein said imaging means is a CCD camera. 4. A base member mounted on a stage,
A reference mark provided on the stage and a predetermined work member are imaged by predetermined imaging means, and the reference mark in the obtained captured image is aligned with the position of the work member according to the position of the work member. A control method of a registration device, wherein the reference mark and an auxiliary mark provided near the reference mark are provided on the stage, and the reference mark is present in a video imaged by the imaging unit. A determining step of determining whether or not the reference mark is within the field of view by the determining step, performing alignment control based on the position of the reference mark and the relative position of the work member; If it is determined in the determining step that the reference mark does not exist, the position of the reference mark outside the field of view and the work member are compared using an auxiliary mark in the image. A control step of calculating a paired position and performing positioning based on the calculated relative position.