JPH0284397A - Direct drawing device and correction of height position measurement data thereon - Google Patents

Abstract

PURPOSE:To draw a pattern with high quality by providing a reference plane constituting a substantially specular surface on a base for mounting thereon a body to be scribed, and providing the reference plane with a projected pattern or recessed groove comprising at least two parts extended respectively along X-direction and Y-direction. CONSTITUTION:A reference plane 18 is provided in the vicinity of a left upper corner part of an upper surface of a base 14, which is a movable table of an X-Y stage device. The reference plane 18 is formed as a nearly specular flat surface to constitute a rectangular area, and is provided with a crossed recessed groove 19 comprising two recessed grooves 19x, 19y extended respectively along X-direction and Y-direction which are orthogonal to each other and in which the base 14 is moved. The positional relationship between a paste ejecting point P at which a perpendicular extended from a nozzle end 11a touches the upper surface of the base 14 and a measuring spot Q at which a laser spot beam from a height sensor 16 strikes the upper surface of the base 14 is designed to have a distance of D therebetween in the X-direction, and the positions for mounting a nozzle 11 and the sensor 16 on a support plate 2 are adjusted. A deviation is detected easily and accurately by use of the height sensor 16, and is used as a correction quantity from position data on points of measurement by the sensor 16.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a method for measuring the height of the surface to be drawn, which is measured in advance by a height sensor, while relatively moving the nozzle and the object to be drawn, such as a heat-resistant ceramic substrate. The present invention relates to a direct writing apparatus for forming a thick film circuit on an object to be drawn by discharging a circuit forming paste from a nozzle whose height position is controlled based on data, and a method for correcting height measurement position data thereof.

[Conventional technology]

BACKGROUND ART After drawing a predetermined circuit by discharging a circuit forming paste onto a heat-resistant ceramic substrate such as an alumina substrate using a direct drawing device, the paste is fired at a high temperature to form a thick film circuit pattern.

Depending on the type of circuit forming paste (hereinafter referred to as "paste") discharged from the nozzle, thick films of various shapes such as conductors, resistors, and non-conductors can be formed. An electrical circuit is constructed by stacking film layers.

FIG. 6 is a perspective view of such a conventional direct drawing device, in which a support plate 2 is fixed to a frame 1 of the device, and a Z-direction motor 3 is held on top of this support plate 2 by a motor holding member 4. There is.

The rotating shaft of this Z-direction motor 3 is connected via a coupling 5 to a ball screw 7 supported by a bearing receiver 6 housing a bearing, and this ball screw 7 is screwed into a nozzle holding member 8. The nozzle holding member 8 is attached to the support plate 2 by a linear slider 9 so as to be slidable up and down.

A cylinder 10 integrally equipped with a nozzle 11 is attached to this nozzle holding member 8.
A paste 13 is discharged from the nozzle end 11a onto an object to be drawn, for example, a ceramic substrate 12.

At that time, the ceramic substrate 12 is
It is positioned and mounted by a plurality of positioning pins 17 on a base 14 that is driven by a Y stage device in the X direction and the Due to the relative movement, a desired thick film pattern is drawn by the paste discharged from the nozzle end 11a.

Further, a height sensor 16 for measuring the height of the drawing surface of the ceramic substrate 12 using laser light is attached to a holder 15 fixed to the support plate 2 in parallel with the nozzle 11.

FIG. 7 is a block diagram of the control system of this direct drawing device, and the control unit 22 is a microcomputer consisting of a CPU as a central processing section, a ROM as a program memory, a RAM as a data memory, and an Ilo as an input/output section. It is composed of.

Then, this control unit 22 causes the electropneumatic converter 24 to control the air pressure from the air source 23 based on the output signal, and also controls the opening and closing of the solenoid valve 25 to supply the required air pressure to the cylinder 10 equipped with the nozzle 11. and cylinder 1
The paste in 0 is discharged from the nozzle end 11a of the nozzle 11.

Further, this control unit 22 includes a motor controller 26
, 28 and 51, and output signals to the driver 27.
, 29.32, the Z-direction motor 3. also shown in FIG. The X-direction motor 30 and the X-direction motor 33 of the XY stage device are each pivotally controlled to control the height of the nozzle 11, and the base 14, which is a moving table on which the ceramic substrate 12 is placed, is stored in the RAM. The image is moved in the XX direction based on the drawn drawing data.

Note that the drawing surface 12a of the ceramic substrate 12 is quite uneven, although it is on the order of microns, and in some cases, a thick film pattern has already been formed. While fixing the height position of the sensor 16 and moving the base 14 in the XX direction, the height sensor 16 measures the height of each coordinate position of the entire drawing surface 12a of the ceramic substrate 12, and calculates the height. The data is input to the control unit 22 and stored in the RAM together with the coordinate position data of each measurement point.

Based on the height data stored in the RAM, the control unit 22 controls the Z-direction motor 3 to beat as described above during drawing to adjust the height of the nozzle 11 to the drawing surface 12a of the ceramic substrate 12. The interval is controlled to be kept constant so that the nozzle end 11a does not come into contact with the drawing surface 12a or the previously formed pattern and become unable to draw, or the nozzle end 11a does not come into contact with the drawing surface 12a or the previously formed pattern, or the line width of the pattern becomes thin due to excessive misalignment. do it like this.

Further, an operation panel 34 for displaying operations and a controller 35 for inputting drawing data are connected to the control unit 22 as external devices.

With such a direct drawing device, the basic line width that can be drawn with one discharge is determined by the type of paste used and the amount of air pressure used to discharge the paste, and the basic line width can be adjusted by selecting the paste used and the air pressure. can be set freely.

In actual drawing, circuit pattern data is created using, for example, a CAD system, and the circuit pattern data and the above-mentioned drawing conditions are input as drawing data to the control unit 22 for drawing.

[Problem to be solved by the invention]

In such a conventional direct writing device, the nozzle 11
When installing the height sensor, the distance is mechanically adjusted with high precision, and the distance between the paste discharge point from the nozzle end 11a and the height measurement point by the height sensor 16 relative to the base 14 is set to a design value (for example, 650mm).

However, in reality, the holder 15 in FIG.
Due to errors in thread cutting and installation for screwing the height sensor 16 to the holder 15, the screw cutting error and installation for screwing the height sensor 16 to the holder 15 are approximately several tens of μm in each of the X and Y directions. Errors often occur, making adjustment very difficult.

This corresponds to the diameter of one ga diameter of a pattern drawn by paste, and the height of each coordinate position on the drawing surface of the ceramic substrate 12 is measured by the height sensor 16 before starting drawing as in the case of multiplexing. Even if the data is stored in the RAM in the control unit 22, the coordinate position data and the actual measurement point (the position of the laser spot) may deviate from each other.

Therefore, if only the X coordinate of that coordinate position is shifted by the design value and used as the position coordinate of the nozzle end 11a, and the height position of the nozzle 11 is controlled based on the height data of that point,
In reality, control may be performed based on height data at a position that is shifted by the width of the pattern in the X and Y directions on the drawing surface, and the nozzle end 11a may be formed in front of or on the drawing surface 1-2a. There has been a problem in that the drawing quality may deteriorate due to contact with the drawn pattern, making drawing impossible or unstable, or being too far away from the drawing pattern, resulting in thinning of the line width of the pattern.

In order to solve the problems in the conventional direct drawing apparatus, this invention eliminates the error in the positional relationship between the height sensor D measurement point and the nozzle end with respect to the designed value without making highly accurate mechanical adjustments. The object of the present invention is to easily detect the height measurement position data and correct the height measurement position data, thereby improving the drawing quality.

[Means to solve the problem]

In order to achieve the above object, the present invention provides a direct writing apparatus as described above, in which the upper surface of the base has a substantially mirror surface, and the direction of relative movement between the nozzle and the base is in the X direction and the Y direction, which are orthogonal to each other. A reference surface is provided with a convex line or a concave groove formed in at least two sections along each side.

Furthermore, a method for correcting height measurement position data using a first-order procedure in a direct writing apparatus provided with the reference plane is also provided.

(2) Position the measurement spot of the height sensor at a reference point that should be separated by predefined distances 1ia and b in the X and Y directions, respectively, from the protrusions or grooves in the reference plane.

■ After that, while detecting the height of the reference surface with the height sensor, the height sensor and the base are moved relative to each other in the X direction, and the relative movement distance is covered until the height sensor detects the protrusion or groove. Let be A.

■ Return the measurement spot of the height sensor to the reference point again.

■ After that, while detecting the height of the reference surface with the height sensor, the height sensor and the base are moved relative to each other in the Y direction until the height sensor detects a protrusion or groove. Let the distance be B.

(2) Calculate a-A and b-B from each measurement result and store them in the memory as position data correction amounts in the X direction and Y direction, respectively.

■ The position data in the X and Y directions of each measurement point when the height of the drawing surface of the object to be drawn is measured by the height sensor,
Correction is performed using the X-direction and Y-direction position data correction amounts stored in the memory.

[For production]

The reference surface on which the protrusions or grooves are formed can be provided with high accuracy by forming it directly on a part of the upper surface of the base, or by forming it separately and attaching it.

Even if there is a slight error in the position of the nozzle and height sensor when mounting the nozzle and height sensor on the support plate, by using this reference surface, the error can be accurately detected as described above, and the object to be drawn can be accurately detected. Measured position data during height measurement can be corrected using software.

In other words, the distance from the reference point in the reference plane to the convex line or groove
The actual distances A and B in the direction and Y direction are determined by moving the height sensor and the base relative to each other in the It can be easily measured as the distance traveled until detection.

The difference a between this measurement ratio @A, B and the designed distances a, b -
A and b−B are the errors in the X direction and Y direction, respectively, that is, the amounts by which the position data (XY coordinates) of the measurement point should be corrected.

Therefore, by memorizing each correction amount and correcting the position data of each measurement point when the height sensor actually measures the height of the drawing surface of the object to be drawn, it is possible to obtain accurate measurement position data. If height data can be obtained and the height of the nozzle during drawing is controlled based on that data, a high quality drawing pattern can be obtained.

〔Example〕

Hereinafter, one embodiment of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a perspective view of the main parts of a direct drawing apparatus which is an embodiment of the present invention, and the same parts as in FIG. 6 are denoted by the same reference numerals, so a description thereof will be omitted.

This embodiment is different from the conventional device shown in FIG.
The reference plane 18 is provided near the upper left corner of the upper surface of the base 14, which is the movable table of the Y stage device.

This reference surface 18 is defined by the positioning pin 1 as shown in FIG.
Although it is preferable to provide it in a portion outside of 7 where an object to be drawn, such as the ceramic substrate 12, is not placed, since the height of the object to be drawn can be measured immediately after determining the correction amount, it is not essential.

The reference plane 18 is formed into a plane close to a mirror surface, and forms a rectangular area as shown in FIG.
A cross-shaped groove 19 is formed by book grooves 19x and 19y. Note that a cross-shaped protrusion may be formed instead of this groove.

If the grooves 19x and 19y are directly carved on the upper surface of the base 14, which is the movable table of the XY stage device, they can be formed with high accuracy at the Y and X coordinate positions defined in the design.

In this embodiment, the perpendicular line from the nozzle end 11a is the base 14.
The positional relationship between the paste discharging point P that hits the top surface and the measurement spot (measurement point) Q where the laser spot light from the height sensor 16 hits the top surface of the base 14 is that the coordinate positions in the Y direction are the same, and the coordinate positions in the X direction are the same. The nozzle 11 and the height sensor 16 are mounted on the support plate 2 so that the nozzle 11 and the height sensor 16 are mounted at a distance of D=650 mm.

Therefore, if the coordinates of point P are (z, v) = (0, O), the coordinates of measurement spot Q are COCt y ) = (6
50, O).

However, in reality, due to accuracy errors during installation,
As shown in Figure 1, the measurement spot Q is
It is shifted by Δx in the direction and Δzo in the Y direction.

Therefore, this amount of deviation can be easily and accurately detected using the reference plane 18, and can be used as the amount of correction of the position data of the measurement point by the height sensor 16.

The control system of this embodiment is the same as that of the conventional example explained with reference to FIG. , a processing program for determining the above correction amount and storing it in the RAM, and a processing program for correcting the position data of each measurement point during or after measuring the height of the object to be drawn.

Further, as the height sensor 16, a triangulation type distance sensor using a laser spot light is used, but it is preferable to use a distance sensor as shown in FIG. 4, for example.

This consists of a small, high-output semiconductor laser 41 and a semiconductor device detector (Posit) with high resolution and high-speed response.
ion S sensitive device (hereinafter abbreviated as rP S DJ) 42, the laser light from the semiconductor laser 41 that is the light source is focused by the projection lens 43, and the target object to be measured is 45 as a spot light f1, and the target object 4
The reflected light f2 from 5 is transmitted to the pSD 42 by the light receiving lens 44 disposed at a predetermined distance from the light projecting lens 43.
The structure is such that the light is collected and received at a single point on the light-receiving surface.

Since the angle θ of the reflected light f2 focused by the light receiving lens 44 changes due to the displacement of the target object 45 in the direction of the arrow, the position of the focused spot on the PSD 42, that is, the light receiving position Displace. This light receiving position X can be easily detected by the PSD 42.

Therefore, if the distance between the optical axes between the light projecting lens 43 and the light receiving lens 44 is d, and the distance between the light receiving lens 44 and the PSD 42 is F, then the distance to the target object 45 can be determined by the following equation.

L=d-F/X Next, the correction amount determination process by the control unit of this embodiment will be explained with reference to the flowchart of FIG.

When this process is started, first, in step 1, the base 14 on which the XY child table of the XY stage device is located is moved so that the measurement spot Q of the height sensor 16 hits the reference plane 18.

Next, in step 2, as shown in FIG.
o, o), the measurement spot Q with respect to this intersection C
is located at a reference point whose coordinates should be (Z, V) = (a, b).

That is, the base 14 is moved so that the measurement spot Q hits a point defined in the design at a distance a from the groove 19y and a distance from the groove 19x within the reference plane 18.

Then, in step 3, the height sensor 16 detects the current position (the measurement spot Q hits the flat part of the reference surface 18).
Measure the height and store the result as the reference height.

Then, in step 4, move the base 14 one step in the X direction (
It is moved closer to the groove 19y by a distance corresponding to the minimum resolution of movement in the X direction (5 microns in this embodiment), and the amount of movement in the X direction after the start of the movement is defined as A.

In step 5, the height at that position is measured by the height sensor 16.

In step 6, it is determined whether the measured value has changed by a predetermined value or more with respect to the previously stored base height, that is, whether or not the groove 19y has been detected.

Then, if there is no height change, repeat steps 4 to 6.
The height is measured while moving the base 14 one step at a time in the X direction, and if there is a change in height, the process proceeds to step 7 and the value of A at that time is stored.

Next, in step 8, the base 14 is placed in the state of step 2 (second
Return the measurement spot Q to the position shown in the figure).
In step 9, move the base 14 one step in the Y direction (corresponding to the minimum resolution of movement in the Y direction, 5 microns in this example).
The amount of movement in the Y direction after the start of the movement is defined as B.

In step 10, the height at that position is measured by the height sensor 16, and in step 11, it is detected whether the measured value has changed by more than a predetermined value with respect to the previously stored reference height, that is, the groove 19x is detected. Determine whether or not.

If there is no change in height, repeat steps 9 to 11 and measure the height while moving the base 14 one step at a time in the Y direction. If there is a change in height, proceed to step 12 and proceed to step 11 at that time. Store the value of B.

Furthermore, in step 13, (a-A) and (b-B) are calculated, and these are calculated based on the accuracy error ΔX during installation.

It is determined that it is Δzo, and the position data of the point measured by the height sensor 16 in the X and Y directions is stored in the memory (RAM) as correction amounts, and this processing is terminated.

Thereafter, as shown by the imaginary lines in FIG. 1, the ceramic substrate 12, which is the object to be drawn, is positioned and placed on the base 14 using a plurality of positioning pins 17, and the height of the entire drawing surface is increased. The position data (coordinate values) of each measurement point at the time of measurement are corrected by the correction amounts (a-A) and (b-B) in the X and Y directions previously stored in the memory. do.

That is, when the coordinates of the paste ejection point P by the nozzle 11 in FIG. 1 are (x, y) = (0, O), the coordinates of the measurement spot Q are (Z, V) = (650 + (a-A
), (b-B)).

Therefore, by measuring the height of a point where the base 14 is moved by the corrected coordinates from the east discharge point P by the nozzle 11, it is possible to accurately measure the height of the paste discharge point.

In this way, there will be no error in the position data of each height measurement point on the drawing surface by the height sensor 16, and it is possible to obtain height data that accurately corresponds to the paste discharge position. By controlling the height of the nozzle 11 during drawing.

High quality drawing patterns can be obtained.

In the above embodiment, the reference surface 18 is formed directly on a part of the upper surface of the base 14, and the groove 19 is directly carved therein. However, the upper surface on which the groove 19 is formed has a substantially mirror surface. A reference surface may be created separately and attached to a predetermined position on the upper surface of the base 14 by pasting or the like.

Furthermore, the shape of the groove 19 formed on the reference surface 18 is not limited to a cross shape, but may be formed into various shapes such as a hook shape or a rectangle, as shown in FIGS. 5(a) to (e), for example. It is possible to have at least two portions along the X direction and the Y direction, which are orthogonal to each other in the direction of relative movement between the nozzle and the base.

Furthermore, as described above, protrusions may be formed on the reference surface 18 instead of these grooves, and in this case, the protrusions may be formed by printing.

However, it is necessary that the thickness of the ink coating layer is such that it can be detected by a height sensor.

Furthermore, the present invention can also be applied to an apparatus that measures the height and applies paste by fixing the base side on which the object to be drawn is placed and moving the height sensor and nozzle side in the X and Y directions. It can be applied to

〔Effect of the invention〕

As described above, in the direct drawing bag according to the present invention, a reference surface having a substantially mirror surface is provided on the base on which the object to be drawn is placed, and at least two sections along the X direction and the Y direction are provided on the reference surface. Since a convex or concave groove is formed, if this reference surface is used, the amount of deviation of the measurement point position from the design value due to positional error, that is, the amount to be corrected, can be easily detected when mounting the height sensor. be able to.

Further, according to the method for correcting pitch measurement position data according to the present invention, the amount of correction of the measurement point position data of the height sensor is obtained using the reference plane, and thereby the drawing surface of the object to be drawn by the height sensor is determined. By correcting the position data of each measurement point when measuring the height of , high quality drawing patterns can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of the main parts of a direct drawing device showing an embodiment of the present invention, FIG. 2 is an enlarged view of its reference plane, and FIG. 3 is a flowchart of the correction amount determination process according to this embodiment. FIG. 4 is an explanatory diagram showing an example of a height sensor used in this embodiment. FIGS. 5(a) to (e) are enlarged views showing other different examples of the reference plane in this invention, and FIG. 6 is a perspective view showing the external appearance of a conventional direct writing apparatus to which this invention is applied. . FIG. 7 is a block diagram of the control system. 2... Support plate 3... Z direction motor O.
... Cylinder 11 ... Nozzle 2 ... Ceramic substrate (object to be drawn) 3 ... Paste 14 ... Base 5 ... Holder 16 ... Height sensor 7 ... Positioning pin 18 ... Reference surface 19 ... Concave groove 2
2... Control unit 30... X direction motor 33
...Y direction motor 1 12 Ceramic substrate (object to be treated) Fig. 5 Fig. 6

Claims (1)

[Scope of Claims] 1. A base on which an object to be drawn is placed, a nozzle fixed at a predetermined interval, and a height sensor are provided so as to be movable relative to each other in a direction orthogonal to the height direction, and the height sensor The nozzle and the object to be drawn are moved relative to each other in the direction while controlling the height of the nozzle based on the height data for each position of the entire drawing surface of the object to be drawn, which has been measured in advance by In a direct drawing device for forming a thick film circuit on the object to be drawn by discharging a circuit forming paste, the upper surface of the base has a substantially mirror surface, and the nozzle and the base are perpendicular to each other in a direction of relative movement. 1. A direct writing device characterized in that a reference surface is provided with a convex groove or a concave groove formed in at least two portions along the X direction and the Y direction, respectively. 2. The direct drawing apparatus according to claim 1, wherein the measurement spot of the height sensor is set at a predefined distance a, from the protrusion or groove in the reference plane in the X direction and the Y direction, respectively.
After positioning the base at a reference point that should be separated by distance b, the height sensor and the base are relatively moved in the X direction while the height sensor detects the height of the reference surface, and the height sensor Let A be the relative movement distance until detecting the protrusion or groove, and after returning the measurement spot of the height sensor to the reference point again, while detecting the height of the reference surface with the height sensor. The height sensor and the base are relatively moved in the Y direction, and the relative movement distance until the height sensor detects the protrusion or groove is defined as B, and from each measurement result, a-A and b-B is calculated and stored in memory as position data correction amounts in the X direction and Y direction, respectively, and the X direction of each measurement point when the height of the drawing surface of the object to be drawn is measured by the height sensor. and the position data in the Y direction,
A method for correcting height measurement position data, characterized in that correction is performed using position data correction amounts in the X direction and Y direction stored in the memory.