JPH09293771A - Movement control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable a stage to be highly accurately positioned at a prescribed target position by one or two correctional actions. SOLUTION: A movement device is equipped with a guide means mounted on a frame 100, a slide member 5 which is movable as guided by the guide means, a drive means 12 which moves the slide member 5, a position detector 11 which is capable of continuously detecting the position of the slide member 5, a reference means provided to the slide member 5, a measuring means 8 capable of measuring the position of the reference means, and a control means 9 which controls the drive means 12 receiving signals emitted from the position detector 11 so as to enable it to move and control the slide member 5. A movement control method is carried out through such a manner that errors of position detection made by the position detector 11 are previously measured and stored in the control means 9, and when the slide member 5 is moved to a predetermined target position, a necessary movement ΔX front the position of the reference means measured by the measuring means 8 to a target position is obtained, furthermore a position detection error e before a movement is made and a position detection error e0 after the slide member 5 is moved by a distance of ΔX are estimated basing on the position detection error stored in the control means 9, then a movement instruction given to the drive means 12 is calculated at a distance of ΔX-(e0 -e)}, and the slide member 5 is moved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a movement control method for highly accurately positioning a stage used in manufacturing an ink jet head or the like.

[0002]

2. Description of the Related Art Conventionally, when a stage is positioned at a predetermined target position, a necessary amount of movement is calculated from the relative positional relationship between the target position and the current position, and the stage is moved using that amount as a command value.

[0003]

However, in such a conventional example, since the actual movement amount of the stage is different from the command value, sufficient accuracy cannot be obtained by the correction operation once or twice. There were cases where the correction operation took a long time and the stage overruns.

Further, the error between the actual movement amount of the stage and the command value is different depending on the stage position in position detection by a resolver or the like, and there is a fluctuation due to temperature and a temporal fluctuation, so that a sufficient correction operation is limited. It was difficult to do it within the given time.

The first object of the present invention is to provide one or two stages.
This is to perform highly accurate positioning at a target position determined by one correction operation. A second object of the present invention is to achieve the above first object with an inexpensive structure without newly adding a position detector other than a resolver generally used as a position detector to a linear motor or the like. It is in. Third of the present invention
The purpose of is to prevent the image from wobbling due to the vibration of the camera, which serves as a reference for positioning the stage. A fourth object of the present invention is to achieve the first object without overrunning the stage.

[0006]

In order to achieve the above object, in the present invention, the required movement amount ΔX is first obtained from the difference between the actual current position of the slide member (stage) and the target position, and further, The position detection error e before the movement and the position detection error e ₀ at the position moved by ΔX are predicted from the data of the position detection error of the slide member which is measured and stored in advance, and the movement command value of the slide member is calculated by ΔX. −
(E ₀ −e), and is characterized by moving. As a result, it is possible to perform highly accurate positioning with the position detection error corrected.

In a preferred embodiment of the present invention, the position detecting means is a resolver generally used in an inexpensive linear servomotor. Further, the measuring means,
CC showing the reference mark formed on the slide member
This is an image processing apparatus capable of capturing and processing the signal of the D camera, and the CCD camera is fixed to a frame. As a result, it is possible to perform highly accurate positioning with an inexpensive configuration without adding a new position detecting means, and it is possible to easily prevent image fluctuation due to camera vibration. Furthermore, the step of moving the slide member to the target position is the same as the first step of controlling the movement slightly before the target position as the first target, and the same movement control method from the first target slightly before to the target position. In the second step, the movement is controlled again. This allows highly accurate positioning without overrunning the slide member.

The present invention is particularly applicable to an ink jet head including a base plate and a plurality of heater boards arranged on the base plate in a substantially closely contacting state.
It is suitable when the heater boards are sequentially arranged on the base plate. In this case, the base plate,
The heater boards are sequentially arranged on the base plate while being sequentially mounted while being mounted on a stage composed of a slide member controlled by the method of the present invention.

[0009]

【Example】

(First Embodiment) Hereinafter, a movement control method according to the present invention will be described.
An embodiment applied to a device for sticking a semiconductor chip to a base member with high precision will be described with reference to the accompanying drawings.

FIG. 1 is a block diagram of an apparatus for sticking a chip to a base member with high precision. A vacuum finger 2 holding the chip 1 can be moved and rotated by a YZθ stage 3, and a base member 4 is used. , X stage 5 to move. Further, the scale 6 is mounted on the X stage 5 and is movable together with the base member 4, and a reference mark 7 is drawn on the lower surface of the scale 6 as shown in FIG. The CCD camera 8 fixed to the scale 6 and the pedestal 100 is arranged by the CCD camera 8 so that both the chip 1 and the scale 6 are within the field of view.

Further, the controller 9 controls the X stage 5 and YZθ.
While obtaining the position information of the stage 3, the image processing apparatus 10
The position information of the reference mark 7 (FIG. 2) and the corner of the chip 1 is obtained by the control of the X stage 5 and the YZθ stage 3. The reference marks 7 are provided in the X direction so that at least one of the reference marks 7 is in the visual field of image processing (the visual field of the CCD camera 8) at any position where the X stage 5 is attached. In this embodiment, the visual field of image processing is 0.3 mm square, and the pitch of the reference marks 7 provided on the lower surface of the scale 6 in a straight line in the X direction is 0.2 mm. The position detection time of the image processing 10 is 100 to 200 mS
X stage 5 and YZθ stage 3 because of the degree
Is driven and controlled by a servo system using a faster resolver and encoder. The controller 9 gives a target position for feeding the X stage 5 and the YZθ stage 3 to these servo systems as a command position.

Reference numeral 12 is a linear motor for driving the X stage 5 in the X direction, and 11 is a resolver for detecting the position and moving speed of the linear motor 12 in substantially real time. The control device 9 obtains the required movement amount of the X stage 5 based on the relative position information between the reference mark 7 and the corner of the chip 1 obtained from the image processing device 10, and does not show a pulse train signal corresponding to the required movement amount. Send to linear servo driver. The linear servo driver servo-drives the linear motor 12 based on the detection signal from the resolver 11 so that the X stage 5 moves by a distance corresponding to the pulse train.

FIG. 2 is a diagram showing the visual field of image processing of the CCD camera 8 in the apparatus of FIG. 1, and in this embodiment,
The corner of the chip 1 and the circular reference mark 7 on the scale 6 are included in this field of view, and the relative position information X of the chip 1 and the reference mark 7 is calculated by the image processing device 10.

FIG. 3 is a diagram showing a part of the absolute position error of the resolver 11 of the X stage 5, and the absolute error at that position can be read from the commanded position of the X stage 5. In the figure, the solid curve represents the position detection error stored in the control device 9, and the dotted curve is the expected curve representing the position detection error during operation. P is the current position and Q is the target position. The solid line curve shows the command position and the output data from the laser length measuring device by gradually moving the command position at a fine fixed pitch while measuring the position of the X stage 5 with the laser length measuring device for calibration. Calculated by comparing. The solid curve obtained by the experiment changes in the vertical direction in the figure, and the curve also slightly changes. These fluctuations are two sine curve analog signals in which the output signal of the resolver itself is 90 ° out of phase, and these are compared and converted to a digital signal such as a pulse train and used as a position feedback signal. Although it is general, it is considered that it is affected by distortion and drift due to the original analog signal and fluctuation of the gap inside the resolver.

The operation of the apparatus of FIG. 1 will be described below with reference to steps S1 to S8 of the control flow of FIG. First, in step S1, the chip 1 is lowered by the YZθ stage 3 to a position where the CCD camera 8 is in focus. Step S2
Then, the relative position information X between the chip 1 and the reference mark 7 is obtained from the CCD camera 8 and the required movement amount ΔX = X ₀ −X is calculated. Here, X ₀ is a predetermined target positional relationship between the chip 1 and the reference mark 7.

Next, in step S3, | ΔX |> ε (however,
If ε is the required accuracy), the correction operation of the X stage 5 is performed in steps S4 and S5.

Assuming that the movement command value ΔP of the X stage 5 is ΔP = ΔX in order to perform this correction operation,
From the error curve in FIG. 3, the X stage 5 is actually ΔX + (e
₀ + Δe ₀ −e−Δe). That is, (e ₀
+ Δe ₀ −e−Δe) will be moved to a position different from the target position. Therefore, ΔP = ΔX− (e ₀ −
It is necessary to set e + Δe ₀ −Δe) as the movement command value of the X stage 5. However, since the values of Δe ₀ and Δe change every time, it cannot be stored in advance, but in the experiment, the value of (Δe ₀ −Δe) is compared with (e ₀ −e).
Pretty small.

Therefore, in step S4, ΔP = ΔX−
Let (e ₀ -e) be the movement command value for the X stage 5. Succeedingly, in a step S5, the X stage 5 is relatively moved by ΔP obtained in the step S4. After this step S5, the procedure returns to step S2 for confirmation, the required movement amount ΔX is obtained again, and if it is within the required accuracy ε, the chip 1 is lowered to the base member 4 in step S6, and in step S7 the chip 1 and base The member 4 is adhered, the finger 2 is raised in step S8, and the bonding operation of one chip is completed.

According to this embodiment, the required movement amount ΔX is first obtained from the difference between the actual current position of the slide member and the target position, and further the data of the position detection error of the slide member which is measured and stored in advance. From the position detection error e before the movement and the position detection error e ₀ at the position moved by ΔX
And the movement command value to the slide member is ΔX− (e ₀
Since the movement is made as (e), it is possible to perform highly accurate positioning with a small number of correction operations. In addition, the position detection means using a resolver generally used for an inexpensive linear servomotor has made it possible to perform highly accurate positioning with a small number of correction operations. Furthermore, since the camera that serves as a reference for alignment is fixed, it is possible to easily prevent image fluctuation due to camera vibration.

(Second Embodiment) Next, a case will be described in which a plurality of heater boards used in a long ink jet head are arranged with high precision on a base plate made of aluminum. In this case, it is necessary to arrange multiple heater boards so that they are in close contact, but when aligning the heater boards, if the heater boards that were previously attached are touched, the positions of the heater boards that are previously attached will be misaligned. Or the heater board may be chipped, so the above step S
In the correction operation of 5, the X stage 5 is not allowed to overrun beyond the minimum clearance between the adjacent heater boards.

The amount of overrun is (Δe ₀ −Δ
If e)> 0, only (Δe ₀ −Δe) may occur. Therefore, at the time of the first correction operation, step S
In 4 the target position is just before the target position Δ
P is calculated, and ΔP is calculated with the predetermined target position as the target during the second and subsequent correction operations. Therefore, if the required movement amount ΔX of the X stage 5 is small, naturally (Δe ₀ −Δe) is also small. It is possible to position the X stage with high accuracy without causing overrun, that is, without contacting the lateral chip.

According to the present embodiment, since the step of controlling the movement slightly before the target position as the first target is provided, in addition to the effect of the first embodiment, the slide member is not overrun. , High-precision positioning has become possible.

[0023]

[Modifications of Example]

(1) In the above embodiment, the correction method for the X stage has been described, but a similar correction method is possible for the Y stage. (2) Although the linear motor and the resolver are used as the configuration of the X stage in the above description, the configuration of the servo motor, the ball screw, and the encoder may be used. (3) In the above description, as the error data, the measured value is stored as it is, but it may be stored as a coefficient of an approximate curve such as a quadratic curve in a minute operation range.

[0024]

As described above, according to the present invention, (1) the required movement amount ΔX is first obtained from the difference between the actual current position of the slide member and the target position, and is further measured and stored in advance. The position detection error e before the movement and the position detection error e ₀ at the position moved by ΔX are predicted from the data of the detected position detection error of the slide member, and the movement command value to the slide member is ΔX− (e ₀ Since the movement is made as (e), it is possible to perform highly accurate positioning with a small number of correction operations. (2) High-precision positioning is possible with a small number of correction operations even with position detection means using a resolver generally used for inexpensive linear servomotors. (3) By fixing the camera that serves as a reference for alignment, it is possible to easily prevent the image from fluctuating due to the vibration of the camera. (4) By providing the step of controlling the movement slightly before the target position as the first target, it is possible to perform highly accurate positioning without overrunning the slide member.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a chip attaching device.

FIG. 2 is a diagram showing a field of view of a CCD camera.

FIG. 3 is a diagram showing an absolute position error of a resolver.

FIG. 4 is a diagram showing a control flow.

[Explanation of symbols]

1: Chip, 2: Vacuum finger, 3: YZθ stage, 4: Base member, 5: X stage, 6: Scale, 7: Reference mark, 8: CCD camera, 9: Control device, 10: Image processing device, 11 : Resolver, 12: Linear motor, 100: Stand.

Claims (5)

[Claims] 1. A guide unit attached to a gantry, a slide member that is movable by being guided by the guide unit, a drive unit that moves the slide member, and a position that can continuously detect the position of the slide member. Detecting means, reference means arranged on the slide member, measuring means capable of measuring the position of the reference means, and taking in a signal from the position detecting means to calculate a movement command value to control the driving means. According to the above, in the moving device including the control means capable of controlling the movement of the slide member, the position detection error of the position detection means is measured in advance and stored in the control means, and the slide member is set to a predetermined target position. When the reference position is moved to the target position, the required movement amount ΔX from the current position to the target position is obtained based on the value measured by the measuring unit. The position detection error e before moving and the position detection error e ₀ at the position moved by ΔX are predicted from the position detection error stored in the control means, and the movement command value is ΔX− (e ₀ −e). And the drive means is controlled based on the movement command value and the signal from the position detecting means to move the slide member. 2. The movement control method according to claim 1, wherein the position detecting means is a resolver. 3. The reference means is a mark whose position can be obtained by an image processing apparatus, and the measuring means is C
The movement control method according to claim 1, wherein the movement control method is an image processing apparatus capable of capturing and processing a signal from a CD camera, and the CCD camera is fixed. 4. When the slide member is moved to a target position by the movement control method according to claim 1, a first step of controlling movement just before the target position as a first target,
A movement control method comprising a second step of performing movement control again from the first target slightly before this to the target position by the same movement control method. 5. An ink jet head comprising a base plate and a plurality of heater boards arranged on the base plate in a substantially intimate contact state, wherein the heater board is the base plate described in any one of claims 1 to 4. An inkjet head, which is mounted on a stage composed of a slide member controlled by a method, and sequentially arranged on the base plate while sequentially positioning the base plate by the method.