JP3490355B2 - Paste coating machine - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has a paste discharge port of a nozzle facing a substrate placed on a table and is perpendicular to the main surface of the substrate between the paste discharge port of the nozzle and the substrate. The distance in any direction, and changing the relative positional relationship between the substrate and the nozzle in the direction parallel to the main surface of the substrate while discharging the paste from the paste discharge port of the nozzle onto the substrate. Thus, the present invention relates to a paste applicator for applying a paste pattern of a desired shape onto the substrate, and particularly R, G, B in the manufacture of a plasma display.
The present invention relates to a paste coater suitable for forming phosphors of three colors.

[0002]

2. Description of the Related Art R is used in the manufacturing process of plasma displays.
For the formation of phosphors that emit (red) light, G (green) light, and B (blue) light (hereinafter, these phosphors are referred to as R phosphor, G phosphor, and B phosphor, respectively). As the paste applicator used, there are those proposed in JP-A-10-27543 and JP-A-10-223138.

In all of the paste applicators described in these documents, the paste ejection port at the tip of the nozzle is made to face the substrate placed on the table, and the main portion of the substrate is provided between the paste ejection port and the substrate. An arbitrary distance is provided in a direction perpendicular to the surface (hereinafter, this distance is referred to as a nozzle tip and a distance (distance) between the substrates), and the R, G, and B phosphor pastes are ejected onto the substrate from the paste ejection ports. While changing the relative positional relationship between the nozzle tip and the substrate in a direction parallel to the main surface of the substrate (hereinafter referred to as the relative positional relationship between the nozzle tip and the substrate), the phosphor of a desired shape is formed on the substrate. Paste pattern
Is applied.

In particular, a large number of partition walls (ribs) made of glass opaque to ultraviolet rays are provided on the substrate of the plasma display, and the R, G, B phosphor paste is the substrate between these ribs. Applied over.

[0005]

Among the above-mentioned conventional techniques, in the paste coating machine described in Japanese Patent Laid-Open No. 10-27543, the nozzle tip, the distance between the substrates, the nozzle tip and the distance between the ribs are measured in advance. By changing the relative positional relationship between the nozzle and the substrate while moving the nozzle up and down,
A phosphor paste pattern is applied onto the substrate. The distance between the nozzle tip and the substrate and the distance between the nozzle tip and the rib are measured at three points set on the surface of the substrate and on the rib, and a virtual curved surface passing through these three points detected for each is set. , The nozzle is moved parallel to the virtual curved surface corresponding to it on the surface of the substrate or on the rib.

In the paste applicator disclosed in the above-mentioned JP-A-10-223138, the tip of the nozzle is set at an arbitrary height position above the substrate, a guide is hung from the tip of the nozzle onto the substrate, and the phosphor is applied to this guide. The paste is dropped and applied on the substrate between the ribs, and the distance between the nozzle tip and the substrate is not adjusted significantly.

Since the distance between the ribs is as small as about 150 μm, these conventional techniques are dedicated to accurately applying the phosphor paste between the ribs.

However, the plasma display has a large screen, the substrate of which is thicker than that of the liquid crystal display, and when placed on a table having a flat surface, the surface of the substrate does not become flat, and a wave is generated. I often hit it. Therefore, as in the case of the paste applicator described in JP-A-10-27543, when the distance is measured in advance at three points, the height position of the nozzle tip is made to follow the waviness of the surface of the substrate. It cannot be changed to keep the distance between the nozzle tip and the substrate constant. Therefore, it is conceivable to increase the number of measurement points, but if you do this, the amount of data related to measurement points will increase and a large capacity memory will be required to store this,
In addition, the time required for this measurement becomes long and the process becomes troublesome.

Since the rib is formed by baking glass on the substrate, the unevenness of the surface of the rib is severe, and the fact that the measurement point is on the rib accurately reflects the distance between the nozzle tip and the substrate. Therefore, it is not suitable as a reference for scanning control.

Further, in the case of the paste applicator described in the above-mentioned Japanese Patent Laid-Open No. 10-223138, the distance between the nozzle tip and the substrate is set to be large regardless of the surface condition of the substrate. For this reason, it is necessary to estimate the amount of paste dripping at the beginning and end of application, and it is difficult to control the start and end of paste ejection, and there is a risk that the paste cannot be applied in the desired shape.

The present invention has been made in view of the above points, and an object thereof is to provide a paste applicator capable of forming a paste pattern at a desired position with high accuracy. Especially.

Another object of the present invention is to provide a paste applicator capable of forming a paste pattern at a desired position with high accuracy and high productivity.

[0013]

In order to achieve the above object, the present invention provides a paste discharge port of a nozzle in a direction perpendicular to a main surface of a substrate placed on a table and the substrate. The distance between the sensor and the substrate is measured in a direction orthogonal to the direction in which the relative positional relationship between the substrate and the nozzle changes in a direction parallel to the main surface of the substrate. A sensor, and the sensor preceding the nozzle when changing the relative positional relationship between the substrate and the nozzle in a direction parallel to the main surface of the substrate is at least perpendicular to the main surface of the substrate. Is a sensor for measuring the distance between the paste discharge port and the substrate in various directions, and based on the detection results of these sensors, a direction perpendicular to the main surface of the substrate and parallel to the main surface of the substrate. Orthogonal to the changing direction of the relative positional relationship between the substrate and the nozzle in the direction Those forming a structure for the positioning of the nozzle in direction.

Further, according to the present invention, the sensor preceding the nozzle is a sensor that only measures the distance between the paste discharge port and the substrate in the direction perpendicular to the main surface of the substrate. As a sensor following the nozzle, a sensor for measuring a distance on the substrate in a direction orthogonal to a changing direction of the relative positional relationship between the substrate and the nozzle in a direction parallel to the main surface of the substrate. Is provided, and the position of the nozzle in the direction orthogonal to the changing direction of the relative positional relationship between the substrate and the nozzle is controlled based on the detection results of these sensors.

Further, the present invention provides a sensor preceding and following the nozzle when changing the relative positional relationship between the substrate and the nozzle in a direction parallel to the main surface of the substrate, A sensor that measures the distance between the paste discharge port and the substrate in a direction perpendicular to the main surface of the substrate is provided, and based on the detection result of the preceding sensor, a sensor that is perpendicular to the main surface of the substrate is provided. The direction of change of the relative positional relationship between the substrate and the nozzle based on the detection results of the preceding and following sensors with an arbitrary distance between the paste discharge port and the substrate The configuration is such that the position of the nozzle is controlled in the direction orthogonal to.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view showing an embodiment of a paste coating machine according to the present invention, in which 1 is a pedestal, 2a, 2
Reference numeral b is a substrate conveyer, 3 is a substrate suction plate, 4 is a θ-axis movement table, 5a and 5b are y-axis movement tables, 6 is an x-axis movement table, 7 is a coating head, 8 is a control unit, 9 Is a pneumatic unit, 10 is a monitor, and 11 is a keyboard (operation panel).

In the figure, the substrate transfer conveyors 2a, 2
b is provided with an elevating means, and conveys the substrate K for plasma display manufacture in the x-axis direction and lowers it.
The substrate K is placed on the substrate suction plate 3 and is lifted to receive the substrate K, and is transported in the X-axis direction to be discharged to the outside. Although not shown, the substrate K
A plurality of ribs parallel to the y-axis direction are formed on the top.

The θ-axis moving table 4 rotates the substrate suction plate 3 about the θ-axis, and the y-axis moving tables 5a and 5b drive the x-axis moving table 6 in the y-axis direction. It is equipped with a linear motor and a guide mechanism for ensuring support rigidity.

The coating head 7 is provided on the x-axis moving table 6 and is moved by the x-axis moving table 6 in the x-axis direction.
The monitor 10 displays the operating state and displays the image input state, and the keyboard 11 inputs operating data and operates the apparatus.

Two positioning cameras (not shown) are installed on the pedestal 1. The position of the positioning mark imprinted on the substrate K is read, and the θ-axis moving table 4 is used to set the edges of the substrate K in xy directions. The position is set parallel to the axis, and the position of the substrate K on the substrate suction plate 3 is confirmed.
Further, when these cameras interfere with the moving range of the coating head 7, a camera may be installed under the substrate suction plate 3 so as to pass through the substrate suction plate 3 for image recognition positioning.

FIG. 2 is an enlarged perspective view showing the coating head 7 in FIG. 1, and 12 is a z-axis table base, 1
3 is a z-axis motor, 14 is a Z-axis moving table, 15 is a syringe holding base, 16R, 16G, 16B are R, respectively.
G, B phosphor paste syringe, 17 is a syringe 16
R, 16G, 16B air supply ports, 18 is a syringe 16
R, 16G, 16B paste supply ports, 19a, 19b
Is a remaining paste amount detection sensor for the syringes 16R, 16G, 16B, 20 is a paste storage cylinder lid for the syringes 16R, 16G, 16B, 21 is a nozzle holder, 22 is a nozzle sensor base, 23 is a preceding sensor, 24 is a trailing sensor, 25
Is a nozzle sensor drive mechanism, and 26 is a movement guide mechanism.

In FIG. 1, the z-axis table base 12 is arranged on the x-axis moving table 6, and the Z-axis moving table 14 is for converting the forward / reverse movement of the z-axis motor 13 into the z-axis direction. It incorporates mechanical elements such as ball screws and a guide mechanism. The syringe holding base 15 is a z-axis moving table.
The bull 14 moves in the z-axis direction. Nozzle holder 2
1 includes a syringe 16R containing an R phosphor paste.
The syringe 16G containing the G phosphor paste and the syringe 16B containing the B phosphor paste are fixed, and a plurality of nozzles for discharging the paste described in FIG. 16R, 16G,
16B has a built-in pipe for supplying paste to these nozzles. These syringes 16R, 16G, and 16B are provided with an air supply port 17, a paste supply port 18, paste remaining amount detection sensors 19a and 19b, and a paste storage cylinder lid 2, respectively.
0 is provided. The nozzle sensor base 22 has an opening through which a plurality of nozzles attached to the nozzle holder 21 penetrate.

When the paste remaining amount of the syringes 16R, 16G, 16B is detected by the paste remaining amount detecting sensors 19a, 19b, and the remaining amount is less than the reference amount, the paste tank to be described later is connected to the pipe and the paste supply port. The paste is pressure-fed to the syringes 16R, 16G, and 16B via 18. When the paste is not supplied, the above-mentioned paste supply path is shut off by a valve (not shown).

The leading sensor 23 and the trailing sensor 24 are arranged on the nozzle sensor base 22, and the detection light thereof passes through an opening provided in the nozzle sensor base 22.
The nozzle sensor drive mechanism 25 is provided on the syringe holding base 15 and slightly moves the leading sensor 23, the trailing sensor 24, and the nozzle holder 21 in the x-axis direction. There is also a nozzle moving mechanism that slightly moves only the nozzle holder 21 in the x-axis direction, but the illustration is omitted here. The movement guide mechanism 26 guides the movement of the nozzles and the sensors 23, 24 by the nozzle sensor drive mechanism 25.

The sensors 23 and 24 will be described later in detail.

FIG. 3 is a perspective view showing a process of applying the phosphor paste on the substrate K of this embodiment, which includes 27R,
27G and 27B are nozzles for R, G and B phosphor paste, and 28 is a rib.

In the figure, the nozzle holder 21 has an R
Two nozzles 27R for the phosphor paste, two nozzles 27G for the G phosphor paste, and two nozzles 27B for the B phosphor paste are attached, and nozzles 27R, 27G, 27
B, 27R, 27G, 27B are arranged in this order in the x-axis direction (hereinafter, these nozzles 27R, 27G, 27
B is collectively referred to as a nozzle 27). The substrate K to which the phosphor paste is applied is arranged so that the ribs 28 provided therein are parallel to the y-axis direction. Therefore, the arrangement direction of the nozzles 27 in the nozzle holder 21 is orthogonal to the longitudinal direction of the ribs 28 on the substrate K.

These nozzles 27R, 27G, 27B, 2
7R, 27G, and 27B are adjacent ribs 28 on the substrate K, respectively.
The x-axis moving table 6 to which the nozzle holder 21 is attached is placed in the y-axis moving table 5a, 5 while facing each other.
By moving in the y-axis direction on b (FIG. 1), these nozzles 27 move in the y-axis direction, and at the same time, from the paste discharge port (not shown) at the tip of the nozzle 27R, the syringe 16R (FIG. 2). Of the R phosphor paste P (R) of the nozzle 27G to the paste discharge port (not shown) of the nozzle 27G, and the G phosphor paste P (G) of the syringe 16G (FIG. 2) to the paste discharge port of the tip of the nozzle 27B ( The B phosphor paste P (B) of the syringe 16B (FIG. 2) is discharged from each (not shown), and the R phosphor paste P is placed between every two ribs 28.
(G) is applied with the G phosphor paste P (G) between the adjacent ribs 28 and further with the B phosphor paste P (B) between the adjacent ribs 28, respectively, so that the six ribs 28 are formed.
At the same time, the phosphor paste is applied. When the coating between the six ribs 28 is completed, the x-axis moving table 6 then moves on the y-axis moving tables 5a and 5b by six ribs 28 in the y-axis direction. The above coating operation is performed.

In this manner, the 6-hole type nozzle in which the 6 nozzles 27 are attached to the nozzle holder 21 can simultaneously apply the paste between the 6 ribs 28, but the nozzles 27R, 27G, 27B. It is also possible to adopt a three-hole type in which one nozzle is used or a method in which a multiple of three other than that is used, but for example, when the number of nozzles used in the three-hole type or the six-hole type is small, each nozzle 27 for nozzle holder 2
You may make it detachable with respect to 1 individually. However, in consideration of the mounting accuracy and the workability of mounting, it is possible to use a multi-hole nozzle in which one block is formed with a plurality of holes (for example, a multi-hole nozzle in which a plurality of nozzles 27 are integrally fixed and attached to the nozzle holder 21). Use is desired. In addition, the nozzle holder 2
Nozzle 27 that can be attached by changing the structure of 1.
, The distance between the centers of the nozzles 27, the number of ejectable pastes, and the number of mountable syringes 16 can be easily changed.

Since the phosphors have different physical properties such as viscosity and thixotropy for each emission color, in order to apply these at the same time with high accuracy, an air pressure adjusting device, which will be described later, is used for the syringe 1.
It is advisable to connect every 6 and adjust the discharge pressure according to the type of phosphor paste (phosphor paste having a different emission color).

Although this embodiment relates to the application of the phosphor paste in the plasma display panel, for example, a plurality of single paste patterns are formed at the same pitch, for example, a black stripe forming step or barrier rib formation. When this embodiment is used in the forming process, etc., the number of syringes 16 is set to one, and the coating method for evenly distributing the plurality of nozzles 27 in the nozzle holder 21 and the physical properties such as viscosity and thixo value with the same paste are adjusted. It is also possible to use a coating method in which the pastes are sequentially laminated.

By the way, for a thick substrate K,
In FIG. 1, even if an attempt is made to flatten the surface by sucking the whole surface onto the substrate suction plate 3, it is only partially sucked, the warp is not corrected, and the surface of the substrate K often has undulations. Further, as the substrate K becomes larger, the substrate suction plate 3 becomes larger, and the peripheral region of the substrate suction plate 3 becomes curved due to the weight. Therefore, the substrate K also curves in accordance with the substrate suction plate 3, and the marginal area of the substrate K protruding from the substrate suction plate 3 curves so as to hang down under its own weight.

On the other hand, the x-axis moving table 6 and the coating head 7
Is independent of the warp of the substrate K, the distance between the paste ejection port of the nozzle 27 and the surface of the substrate K (distance: space between the paste ejection port and the substrate K) is the surface of the substrate K. A difference occurs in the relative position of the paste ejection port with respect to the surface of the substrate K in the direction parallel to (x, y axis direction) due to the undulation or warpage of the substrate K.

Therefore, according to the change in the relative position between the paste ejection port of the nozzle 27 and the substrate K in the direction parallel to the surface of the substrate K (here, with the movement of the paste ejection port), the paste ejection port is , The distance between the substrates K is measured, and the distance between the paste ejection port and the substrate K is adjusted and controlled in real time. After this control, the load on the control unit 8 is reduced by appropriately disposing the measurement data.

FIG. 4 is an explanatory view of a specific example of the preceding sensor 23 in FIG. 2 for performing such measurement, and 29 is a non-contact triangulation sensor as the preceding sensor 23, which corresponds to FIG. Are given the same reference numerals.

In the figure, the non-contact triangulation sensor 29
Uses a semiconductor laser as a light source and measures the distance between the paste ejection port and the substrate K by triangulation.

The non-contact triangulation sensor 29 has a light emitting portion and a light receiving portion therein, emits laser light (detection light) L1 from the light emitting portion, and measures the laser light L1 on the surface of the substrate K. The length is measured by reflecting the light at the point S1 and receiving the light by the light receiving unit. The rib 28 is used to irradiate the laser light L1.
It is arranged to be parallel to the longitudinal direction of.

With the preceding sensor 23, the paste discharge port,
By measuring the distance between the substrates K, the undulation or warpage of the surface of the substrate K is detected, and based on the detection result, the paste discharge port of the nozzle 27 is separated from the surface of the substrate K by a predetermined desired distance (distance). 2), the z-axis motor 13 (FIG. 2) is controlled in real time.

As the preceding sensor 23, an optical probe type known as an autofocus type, an image measuring type, an ultrasonic type, a magnetic type or the like sensor may be used instead of the triangulation type sensor.

FIG. 5 is an explanatory view of a specific example of the trailing sensor 24 in FIG. 2, and 30 is a non-contact triangulation sensor as the trailing sensor 24, and the portion corresponding to FIG. The same reference numerals are attached.

In the figure, the non-contact scanning sensor 30
Uses a semiconductor laser as a light source to measure the distance (distance) between the surfaces of the phosphor paste P applied on the substrate K.

The non-contact scanning type sensor 30 measures two-dimensional displacement by scanning linearly by an optical scanning mechanism provided inside. This non-contact scanning sensor 30 is
The laser light (detection light) L2 is arranged so that the scanning direction thereof is perpendicular to the rib 28. Note that the applied phosphor paste P is omitted in FIG.

The non-contact scanning type sensor 30 uses the laser beam L2.
The distance to the phosphor paste P is sequentially measured (detected) in accordance with the scanning of, and the position in the direction perpendicular to the ribs 28 is determined. Therefore, the distance between the ribs 28 can also be calculated. That is, since the relative positional relationship between the non-contact scanning sensor 30 and the nozzle 27 is known in advance in manufacturing the device, the relative positional relationship of the nozzle 27 with respect to the substrate K in the direction parallel to the main surface of the substrate K is changed. The non-contact scanning sensor 30 measures the distance to the substrate K in the direction (x-axis direction) orthogonal to the direction (y-axis direction).
The position of the nozzle 27 in the direction (scanning direction of laser light) orthogonal to the direction (longitudinal direction of the rib 28, that is, the y-axis direction) of the relative positional relationship between the substrate K and the nozzle 27 based on the detection result of Is controlled in real time so that the nozzle 27 is located at the center between the ribs 28.

A CCD camera for image recognition may be used instead of the non-contact scanning type sensor 30. In this case, the reference position is set on the frame of the image screen, the positional relationship between the reference position and the rib 28 in the image is obtained, and the position of the nozzle 27 is calculated.

Further, the leading sensor 23 and the trailing sensor 2
4, the use of the non-contact triangulation sensor 29 shown in FIG. 4 will be described below with reference to FIG.

In FIG. 6, it is assumed that the paste P is applied to the substrate K while the paste discharge port 27a of the nozzle 27 moves in the y-axis direction. For simplification, here, the paste discharge port 27 of one nozzle 27 is used.
Only a is shown, and the paste discharge ports of the other nozzles are shown by dotted lines.

The paste discharge port 27a ideally moves in the y-axis direction on a solid line R representing the center between the ribs 28, but the ribs 28 are twisted or parallel to each other. Even if there is, if the bias is applied to shift diagonally, finally, the paste ejection port 27a moves between the adjacent ribs 28, so that the paste P crosses over the ribs 28. As a result, the space between the adjacent ribs 28 is applied, and in such a case, when an image is viewed on the plasma display screen, a mixed color occurs and the image becomes blurred.

In order to prevent this, the measurement points Sa and Sb of the leading sensor 23 and the trailing sensor 24 are set on the x-axis with respect to the ideal moving line R which is the center between the ribs 28 through which the paste discharge port 27a should pass. In the direction, the ribs 28 are set at positions at equal intervals d with a margin. According to this, if
When either one of the measurement points Sa and Sb comes to be located on the rib 28, the measurement distance changes significantly, so that the nozzle 27 is attached to the rib 28 on the sensor side where the measurement result changes greatly.
You can see that he is approaching. Therefore, the nozzle 27 is moved to the side opposite to the side where the ribs 28 are close to each other, thereby positioning the nozzle 27 at the center between the ribs 28. At this time, since the nozzle 27 has not yet crossed over the rib 28, the phosphor paste is not applied between the adjacent ribs, and thus the color mixture of the phosphor can be avoided in real time.

Since the surface of the substrate K and the surface of the phosphor paste P are sufficiently bright with respect to the ribs 28, various sensors can be used as the sensors 23 and 24 for measurement. Disturbances such as undulations and bends of the ribs 28 are not extreme. Therefore, for example, even when using the six nozzles 27 as shown in FIG.
It is sufficient to provide 3 and the trailing sensor 24. In this case, as a matter of course, the preceding sensor 23 is the paste P.
The distance to the surface of the substrate K not coated with is measured.

The relative displacement of the nozzle 27 with respect to the substrate K in the x-axis direction is achieved by slightly moving the nozzle holder 21 in the x-axis direction by the nozzle sensor drive mechanism 25 (FIG. 2) built in the coating head 7. Yes, but coating head 7
You may make it move itself.

FIG. 7 is a block diagram showing a specific example of the control system of the embodiment shown in FIG. 1. 8a is a microcomputer unit, 8b is an image input section, 8c is an external interface section, and 8d is Drive controller, 8e is a data communication bus,
31 to 34 are servo motors, 35 to 39 are encoders,
40a and 40b are image positioning cameras, 41 is a positive pressure source, 42 is a negative pressure source, 43 is a positive pressure regulator, 44 is a negative pressure regulator, 45 is a valve unit, 46 is a tank, 47 is a valve, and 48 is Printer, 49 is an external personal computer, 50, 51
Is an actuator, and the same reference numerals are given to the portions corresponding to the above drawings.

In the figure, servomotors 34 and 33 drive the y-axis movement tables 5a and 5b, respectively, a servomotor 32 drives the x-axis movement table 6, and a servomotor 31 the θ axis. The moving table 4 is driven. Further, the encoders 35 to 39 respectively detect the positions of the motors. The actuator 50 is a drive source of the nozzle sensor moving mechanism 25, and the actuator 51 is a drive source of the nozzle moving mechanism omitted in FIG. Further, the external personal computer 49 and the printer 48 are properly connected.

FIG. 7 shows a specific configuration of the control unit 8 in FIG. 1, the air pressure control system of the syringe 16 and the control system of the coating head 7.

Further, in FIG. 7, for simplification, the pneumatic control system is represented by a system of a syringe 16G for accommodating the G phosphor paste.
The phosphor paste is stored, and the valve 47 is controlled to be opened and closed according to the detection results of the paste remaining amount detection sensors 19a and 19b (FIG. 2).

Further, here, the preceding sensor 23 preceding the nozzle 27 is the non-contact triangulation sensor 51 shown in FIG.
A CCD camera for image recognition is used as the trailing sensor 24.

In the figure, the control unit 8 includes a drive control system for the substrate transfer conveyors 2a and 2b, but it is not shown here.

Further, although not shown, the microcomputer 8a is an R storing a main arithmetic unit and an operation processing program.
In addition to the processing results in the OM and the main operation unit, a RAM for storing the input data from the device connected to the control unit 8 and the operating condition data of the apparatus, an input / output unit for exchanging the data, etc. are provided. There is.

Also, an external personal computer 49 that is appropriately connected
And operating conditions data such as coating shape data and coating condition data input from the keyboard 11 or a network (not shown), and production management data such as the number of plasma display panel productions transferred from the device. The RAM in the microcomputer 8a is stored and stored in an internal storage medium (not shown) such as a hard disk in the external personal computer 49 and an external storage medium such as a floppy disk, and any information among them is output from the printer 48 according to an operator's instruction. Can be printed.

On the basis of data input from the keyboard 11, the external personal computer 49, a network (not shown), etc., the x-axis moving table 6 arranged on the y-axis moving tables 5a, 5b has servo motors 34, 33. Driven by the servo motor 32, the z-axis table base 12 arranged on the x-axis moving table 6 is driven by the servo motor 32.
By driving the z-axis motor 13 on the bull base 20, by the negative pressure distributed from the negative pressure source 42, the substrate suction plate 3
For the substrate K that is vacuum-adsorbed on or fixed by a jig,
Nozzle 27, via the syringe holding base 15, x,
Move an arbitrary distance in the y- and z-axis directions. During the movement, the microcomputer 8a causes the valve unit 45 to
By controlling the positive pressure source 41 to the positive pressure regulator 43.
A slight air pressure is applied to the syringe 16 through the valve unit 45 and the paste discharge port 27 of the nozzle 27.
The phosphor paste P is discharged from a and applied on the substrate K in a desired pattern.

During the horizontal movement of the syringe holding base 15 in the x and y axis directions, that is, during the coating operation, the preceding sensor 23.
Measures the distance between the nozzle 27 and the substrate K, and controls the z-axis motor 13 so that this measured distance is always kept constant.

When the phosphor layer of the plasma display panel is formed as shown in FIG. 3, the rib 28 is used.
The nozzle 27 must always be scanned in parallel with the y direction in the y direction. However, the positional relationship between the positioning mark position (not shown) imprinted on the substrate K and the rib 28 is sufficient for scanning the ribs 28 in parallel. It cannot be said that the dimensional accuracy is high.

Therefore, in this specific example, during horizontal movement of the syringe holding base 15 in the x and y axis directions, that is, during the coating operation, the CCD camera 24 and the non-contact scanning sensor 30 shown in FIG. 5 are used. Scanning is performed in the direction perpendicular to the rib 28, so that the parallelism between the rib 28 and the nozzle 27 in the paste application direction is always kept constant in real time.
The actuator 50 arranged in the nozzle sensor drive mechanism 25 is controlled (tracking).

FIG. 8 is a flow chart showing a specific example of the paste applying operation of the paste applying machine shown in FIG.

In the figure, first, the power is turned on (step 100), and then the apparatus initial setting process is executed (step 200).

In this initial setting, the y-axis movement table 5
a, 5b and the x-axis moving table 6 (FIG. 1) move the z-axis table base 12 (FIG. 2) on the coating head 7 in the x-axis direction, and the paste discharge port of the nozzle 27 is made of phosphor paste. The nozzle 27 is positioned at a predetermined reference position (set at the origin position) on the substrate (actual substrate) K (FIG. 1) that is the target of the paste pattern drawing so that it is positioned at the discharge start position (paste application start point). In addition, the data (paste pattern data) for each of the one or more paste patterns to be applied to the actual substrate K, the position data of the actual substrate K, and the actual paste application to the actual substrate K. The relative speed between the actual substrate K and the nozzle 27 (when such a relative speed is referred to as the coating speed, in particular, the coating speed in this case is referred to as the initial setting coating speed), the nozzle 27 from the surface of the actual substrate K. Height (which is above the nozzle 2
7. It is equal to the distance between the substrates K and determines the height of the paste pattern drawn on the surface of the actual substrate K.
Hereinafter, the coating height is particularly referred to as the initial coating height, and the pressure applied to the syringe 16 that determines the amount of paste discharged from the nozzle 27 (this pressure is referred to as the coating pressure). In particular, the application pressure in this case is referred to as the initial setting application pressure), and further, the position data indicating the paste discharge end position and the measurement position data of the applied paste pattern are set. Be done. These data are input from the keyboard 11 (FIGS. 1 and 7), and the input data are stored in the RAM incorporated in the microcomputer 8a (FIG. 7).

When the initial setting operation (step 200) is completed, the actual substrate K is next mounted on the substrate suction plate 3 (FIG. 1) and held by suction (step 300).

In this substrate mounting operation, in FIG. 1, the actual substrate K is carried in from the outside by the substrate transport conveyors 2a and 2b in the x-axis direction to a position above the substrate suction plate 3, and the substrate transport conveyor 2a is moved by an elevating means (not shown). , 2b
By lowering, the actual substrate K is placed on the substrate suction plate 3.

Next, the preliminary positioning of the substrate K is performed (step 400).

In this process, the rough alignment of the actual substrate K in the x and y axis directions is performed by a positioning chuck (not shown) in FIG. Then, a positioning mark of the real substrate K placed on the substrate suction board 3 is photographed by the image recognition cameras 40a and 40b (FIG. 7), and the image is processed to tilt the real substrate K in the θ direction. Is detected and the servo motor 31 (FIG. 7) is driven according to the detection result,
The inclination in the θ direction is also corrected to perform accurate alignment in the x and y axis directions.

Then, paste pattern application is performed in order from the first paste pattern data in the preset application order (step 500). This pattern coating process (step 500) will be described with reference to FIG.

In the figure, first, the coating conditions are set (step 501). That is, since the RAM built in the microcomputer 8a (FIG. 7) has a storage table for setting the coating conditions, it is necessary to draw the first coating pattern.
The application conditions for the second paste pattern are set such as the application speed, application pressure, and application height. Such settings are performed up to the final paste pattern. In addition, dispensing pattern movement data, start point coordinates, end point coordinates,
The suck back pressure and the amount of nozzle rise after application are set. These settings are to select those required for application from various data initialized in advance in step 200 of FIG. 8 and transfer them to the storage table of the RAM as application conditions.

Next, the nozzle 2 is placed at the set coating start position.
In order to position the paste discharge port of 7, the y-axis moving table
The tables 5a and 5b and the x-axis movement table 6 are driven (step 502), and the z-axis table base 12 (FIG. 2) is moved to move the nozzle 27 to the drawing (coating) start point.

Next, the height of the nozzle 27 is set by the z-axis motor 13 (FIG. 2) (step 503). This set height is the coating height already stored in the RAM, and the distance between the nozzle 27 and the actual substrate K is made equal to this coating height. This height is confirmed by the measurement result of the preceding sensor 23 (FIGS. 2 and 4).

When the above processing is completed, the y-axis movement tables 5a and 5b and the x-axis movement table 6 are driven based on the paste pattern data stored in the RAM in the microcomputer 8a. , By this, the nozzle 2
The paste ejection port 27a of No. 7 moves in the x and y axis directions in accordance with the paste pattern data while facing the actual substrate K (step 504).

In FIG. 7, the air pressure adjusted to the coating pressure by the positive pressure regulator 43 is applied to the syringe 16 from the positive pressure source 41 via the valve unit 45, and the paste is discharged from the paste discharge port 27a of the nozzle 27. Discharging starts (step 505).

At this time, immediately before the paste is discharged, a negative pressure adjusted to suck back pressure by the negative pressure regulator 44 is applied to the syringe 16 from the negative pressure source 42 for a short time through the valve unit 45, and the nozzle 27 The paste accumulated in the paste discharge port 27a is sucked in. As a result, the paste can be applied without the accumulation of the paste at the beginning of the paste pattern.

At the same time as the start of the coating and drawing operation, the microcomputer 8a moves from the preceding sensor 23 to the nozzle 27,
The measured data of the distance between the actual substrates K is input to measure the undulations or warpage of the surface of the actual substrates K, and the z-axis motor 13 is driven according to the measured values, so that the surface of the actual substrate K is removed. The paste pattern is applied and drawn in real time so that the set height of the nozzle 27 is constant, that is, the set height is set (step 506).

Next, in step 507, the microcomputer 8a uses the trailing sensor 24 (FIG. 5) to detect the rib 28.
The distance between this and the reference point position of the trailing sensor 24 is measured, and the measured distance is constant, that is, the paste ejected from the nozzle 27 is located at the center between the ribs 28 (position on the moving line R in FIG. 6). The nozzle sensor moving mechanism 25 (FIGS. 2 and 7) is controlled so that the outlet 27a is positioned.

As described above, the paste pattern is applied while the nozzle 27 is three-dimensionally controlled in real time by the measurement by the leading sensor 23 and the trailing sensor 24 in real time.

Therefore, it is possible to improve the number of plasma display panels to be processed (that is, productivity) without previously measuring the distance between the nozzle 27 and the actual substrate K, and to store the measurement data. No memory is needed to store it. Further, the ejection port 27a of the nozzle 27 can be brought as close as possible to the surface of the actual substrate K so that the distance between the nozzle 27 and the actual substrate K becomes constant even if there is undulation on the surface of the actual substrate K. In addition, the height position of the nozzle 27 can be made to follow this undulation, and the paste pattern shape can be made highly accurate and desired, and the shape of the beginning and the end of the drawn paste pattern can be made to be the desired beautiful shape. Can be one.

The microcomputer 8a then inspects the applied state of the paste pattern by determining the luminance distribution of the image picked up by the trailing sensor 24 (step 508).

In this way, although the paste pattern coating / drawing proceeds, the decision whether to continue or finish the paste pattern coating / drawing operation is made by determining the coating point based on the paste pattern data at the end of the paste pattern to be coated. Or not (step 5
09), if not the end, the process returns to the measurement process of the waviness of the surface of the actual substrate K, that is, the coating height control process of step 506, and the series of processes from step 507 to step 509 is executed.

After that, when the application end of the paste pattern is reached (step 509), next, in FIG. 7, a valve unit of pneumatic pressure adjusted from the positive pressure source 41 to the syringe 16 by the positive pressure regulator 43 to the application pressure. The application via 45 is stopped, and the paste discharge from the paste discharge port 27a of the nozzle 27 is stopped (step 510). Then, the z-axis motor 13 is driven to raise the nozzle 27 by the preset amount of elevation (step 511).

Next, the result of the coating state inspection in step 508 is judged (step 512), and the paste pattern coating operation by one operation is completed (step 5).
13).

The above steps 501 to 513
The paste pattern applying operation up to is performed until all the set paste pattern data are used up, that is, until all the paste patterns to be applied are applied (step 513), and when the end of the last paste pattern is reached. (Step 509), while stopping the discharge of the paste (step 510), the z-axis motor 13 is driven to raise the nozzle 27 (step 511), and the paste pattern drawn at the end is inspected (step 512). ), The pattern drawing operation, that is, the pattern application (step 500 in FIG. 8) is completed (step 51).
5).

When an abnormality is detected in the coating state (step 514) in the determination of the coating state inspection result of the paste pattern immediately after coating and drawing performed every time the paste pattern is coated and drawn (step 512), At that point, the pattern drawing process on the actual substrate K is ended (step 515).

When the coating and drawing of the paste pattern on one actual substrate K is completed as described above, the process proceeds to the substrate discharging process (step 600) in FIG. That is, in FIG. 1, the suction of the real substrate K to the substrate suction plate 3 is released, the substrate transport conveyors 2a and 2b are lifted to place the real substrate K thereon, and in that state, the substrate transport conveyors 2a and 2b are placed. Is moved in the y direction, the actual substrate K is discharged to the outside of the apparatus.

Then, it is judged whether or not all the above steps are completed (step 700), and when a paste pattern is applied and drawn on a plurality of real substrates K using the same paste pattern data, The process returns to the substrate mounting process (step 300) for another real substrate K, and the operation (process) described above
Is repeated. Then, when this series of processing is completed for all the actual substrates, all the work is completed (step 800).

Although one embodiment of the present invention has been described above, the present invention is not limited to this embodiment.

For example, in the above embodiment, the nozzle 27 is movable and the actual substrate is fixed when the paste pattern is drawn. However, the present invention is not limited to this, and the nozzle 27 is not limited to this.
May be fixed and the actual substrate K may be movable.

As a method of transporting the actual substrate K, the substrate transport conveyors 2a and 2b transport the substrate K in the x-axis direction to a position above the substrate suction plate 3, but the substrate transport conveyors 2a and 2b are transported in the y-axis direction. Are placed in parallel with the
It may be conveyed in the axial direction.

Further, a triangulation sensor is used as the preceding sensor 23 and a CCD camera is used as the trailing sensor 24. However, as shown in FIG. 6, both sensors 23 and 24 may be triangulation sensors. Good. In this case, since the preceding sensor 23 measures the height in both the forward and backward passes, the coating direction is not limited and it is not necessary to return the coating head 7 to the initial position, further improving the productivity.

[0093]

As described above, according to the present invention,
The paste pattern can be formed at a desired position with high accuracy.

Further, according to the present invention, a paste pattern can be formed at a desired position with high precision and high productivity.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of a paste applicator according to the present invention.

FIG. 2 is a perspective view showing details of a coating head in FIG.

3 is a perspective view showing a process of applying a phosphor paste on a substrate K in the embodiment shown in FIG.

FIG. 4 is an explanatory diagram of a measurement operation of a distance (distance) between a nozzle and a substrate by the non-contact triangulation sensor as the preceding sensor shown in FIG.

5 is an explanatory diagram of a measurement operation of a distance (distance) between a nozzle and a phosphor paste by a non-contact scanning type sensor as a trailing sensor shown in FIG.

FIG. 6 is a diagram showing a nozzle position control method by a leading sensor and a trailing sensor in the embodiment shown in FIG.

FIG. 7 is a block diagram showing a specific example of a control system of the embodiment shown in FIG.

FIG. 8 is a flowchart showing a specific example of the paste applying operation of the embodiment shown in FIG.

9 is a flowchart showing a specific example of step 500 in FIG.

[Explanation of symbols]

3 Substrate suction board 5a, 5b y-axis moving table 6 x-axis moving table 7 Application head 8 control unit 13 z-axis motor 14 Z-axis movement table 15 Syringe holding base 16R, 16G, 16B Phosphor paste syringe 21 nozzle holder 23 Leading sensor 24 trailing sensor 25 Nozzle sensor drive mechanism 26 Movement guide mechanism 27R, 27G, 27B nozzle 27a Paste outlet 28 ribs 29 Non-contact triangulation sensor 30 Non-contact scanning sensor K Plasma display panel substrate P (R), P (G), P (B) phosphor paste

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Shigeru Ishida 5-2 Koyodai, Ryugasaki, Ibaraki Hitachi Techno Engineering Co., Ltd. Development Laboratory (72) Junichi Matsui 5-2-1 Koyodai, Ryugasaki, Ibaraki Hitachi Techno Engineering Development Laboratory Co., Ltd. (56) Reference JP-A-11-119232 (JP, A) JP-A-11-239751 (JP, A) JP-A-8-57382 (JP, A) (58) Fields investigated ( Int.Cl. ⁷ , DB name) B05C 5/00 101

Claims (3)

(57) [Claims] 1. A nozzle having a paste discharge port is provided facing a main surface of a substrate placed on a table at a predetermined distance, and the paste is discharged from the paste discharge port onto the substrate while By maintaining the distance between the paste discharge port and the substrate and changing the relative positional relationship between the substrate and the nozzle in the direction parallel to the main surface of the substrate, a desired shape on the substrate can be obtained. In a paste applicator for applying the paste pattern of, in order to control the change in the relative positional relationship between the substrate and the nozzle,
A first sensor at a position preceding the nozzle for measuring a distance between the substrate and the nozzle in a direction perpendicular to a main surface of the substrate, and a relative position between the nozzle and the substrate. For the changing direction of
Between the substrate and the nozzle at a position following the nozzle in a direction parallel to the main surface of the substrate and in a direction orthogonal to a direction that changes the relative positional relationship between the substrate and the nozzle. of
Measuring the distance, the substrate and the nozzle in the orthogonal direction
Paste applying machine, characterized in that the was the provided <br/> second sensor located to measure the relationship between the. 2. The paste applicator according to claim 1, wherein the second sensor is a scanning sensor. 3. A nozzle having a paste discharge port is provided facing a main surface of a substrate placed on a table at a predetermined distance, and the paste is discharged from the paste discharge port onto the substrate while By maintaining the distance between the paste discharge port and the substrate and changing the relative positional relationship between the substrate and the nozzle in the direction parallel to the main surface of the substrate, a desired shape on the substrate can be obtained. In a paste applicator for applying the paste pattern of No. 3, the first direction that changes the relative positional relationship between the substrate and the nozzle in the direction parallel to the main surface of the substrate
A first sensor preceding the cheat and a second sensor following
Is provided, and the first and second sensors are provided with a second sensor that is orthogonal to the first direction.
In the direction perpendicular to the main surface of the substrate by the first and second sensors, which are arranged at equal intervals on opposite sides of the nozzle .
Simultaneously measure the distance between the paste ejection slot and the substrate
Deeds, based on the detection result of the first sensor, to have any distance between the paste discharge port and the substrate in a direction perpendicular to the main surface of the substrate, said first, second A paste applicator characterized by controlling a positional relationship between the substrate and the nozzle in the second direction based on a detection result of a sensor.