JP3454779B2 - Phosphor coating method for plasma display panel and phosphor layer forming system - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used in a manufacturing process of a plasma display panel (PDP), and a system and a phosphor for forming a phosphor layer between each rib of a substrate having a plurality of ribs (partitions) on its surface. Regarding the coating method.

[0002]

2. Description of the Related Art A PDP is a display panel having a structure in which a pair of substrates (usually glass plates) facing each other across a discharge space are used as a base. In the PDP, by providing the ultraviolet-excitation type phosphor layer in the discharge space, the phosphor layer is excited by the discharge and color display becomes possible. PDP for color display
Has a phosphor layer of three colors of R (red), G (green), and B (blue).

Conventionally, for each of the R, G, and B phosphor layers, a phosphor paste containing powdery phosphor particles as a main component is sequentially applied onto a substrate by a screen printing method for each color, and dried and baked. Was formed by using the method described above (see, for example, Japanese Patent Laid-Open No. 5-299919).

[0004]

[Problems to be Solved by the Invention] However, PDP
As the screen size increases, the rib layout pattern and the mask pattern become misaligned due to factors such as screen mask expansion and contraction / positioning errors, making it difficult to accurately apply the phosphor paste between the ribs. Has become.

The present invention has been made in view of such circumstances, and provides an apparatus and method for uniformly and accurately forming a phosphor layer between each rib of a substrate for forming a large PDP. Is.

[0006]

According to the present invention, a plurality of phosphors having different emission colors are provided in respective grooves formed between a plurality of stripe-shaped ribs provided on a substrate. A method of sequentially applying one color at a time, wherein a plurality of phosphor layer forming apparatuses having nozzles for ejecting phosphor pastes of different viscosities and having different viscosities are prepared, and one phosphor layer forming apparatus is used to form a first phosphor layer on the substrate. One end of the first groove corresponding to the phosphor of one color
From the nozzle toward the other end of the first color firefly
The surface of the paste light paste between the nozzle and the groove
It Hama charging the stringy so by the tension, after the first color paste phosphor filled in the groove of the first dried to the extent that does not cause at least a surface tension, the adjacent to the first groove From one end to the other end of the second groove corresponding to the phosphor of two colors
No. ejected from the nozzle of another phosphor layer forming device toward
Pace two colors of phosphor paste between the nozzle and the groove.
It Hama charge due to the surface tension of the bets in stringy so, the second-color phosphor paste was filled in the groove of the second drying to a degree causing no least surface tension varies from phosphor paste luminescent colors It is intended to provide a phosphor coating method characterized in that filling and drying are alternately repeated.

According to the present invention, phosphors having different emission colors are arranged between adjacent ribs of stripe-shaped ribs arranged in parallel on a substrate.
Arranging a plurality of phosphor layer forming devices to be applied to the groove in series, each phosphor forming device, a mounting table for mounting the substrate, and a dispenser having a nozzle for discharging a phosphor paste of a predetermined viscosity, A carrier unit that relatively moves the nozzle and the mounting table, and a nozzle that controls the carrier unit and the dispenser and discharges the phosphor paste so as to draw a thread between the nozzle and the groove by the surface tension of the phosphor paste. At one end of the groove
And a control unit for moving the phosphor paste toward the other end , and further for drying the phosphor paste applied between the phosphor layer forming devices and applied to the groove on the substrate so that at least surface tension is not generated. A plurality of dryers and a plurality of substrate transporters for transporting the substrate between each phosphor layer forming device and each dryer are provided, and each phosphor layer forming device has a groove corresponding to each color phosphor on the substrate surface. The phosphor paste is sequentially applied to, and each dryer dries the phosphor paste applied to the groove to such an extent that at least surface tension is not generated, and each substrate carrier applies the phosphor paste-coated substrate to the phosphor layer. The phosphor layer is conveyed from the forming device to the adjacent phosphor layer forming device through a dryer, and the phosphor pastes of different emission colors are alternately applied and dried sequentially for each color, and the phosphor layer conforms to the inner surface shape of the groove. Is characterized in that That there is provided a phosphor layer forming system. The present invention includes a plurality of phosphor layer forming devices that apply phosphors having different emission colors to the grooves between adjacent ribs of parallel stripe stripes on the substrate, and each phosphor layer forming device mounts the substrate on the substrate. A mounting table to be placed, a dispenser having a nozzle for discharging a phosphor paste having a predetermined viscosity, a transfer section for relatively moving the nozzle and the mounting table, and a nozzle and a groove by controlling the transfer section and the dispenser. Between the phosphor
While ejecting the phosphor paste so that the yarn is pulled by the surface tension of the ground, the nozzle is directed from one end of the groove to the other end.
And a control unit for moving the phosphor paste, and further, one dryer for drying the phosphor paste applied to the grooves on the substrate at least to the extent that surface tension is not generated, each phosphor layer forming device and the drying device. It is equipped with a single substrate transporter for transporting substrates between machines, each phosphor layer forming device sequentially applies the phosphor paste to the grooves corresponding to the phosphors of each color on the substrate, and the drier applies the paste to the grooves. The phosphor paste is dried at least to the extent that surface tension is not generated, and the substrate transporter transports the substrate coated with the phosphor paste from one of the phosphor layer forming devices to another via the dryer. Provided is a phosphor layer forming system characterized in that a phosphor layer of different emission color is applied and dried alternately for each color to form a phosphor layer along the inner shape of the groove. To do. The present invention is a system for forming a phosphor layer of three types of colors in a groove between adjacent ribs of a plurality of stripe-shaped ribs provided in parallel on a plate at a pitch P, and a plurality of phosphor layers on a substrate are formed. The three phosphor layer forming apparatuses for individually applying the phosphors of three colors to the grooves of the above are arranged with a dryer and a substrate carrier interposed therebetween. A mounting table for mounting, a dispenser in which n nozzles for ejecting a phosphor paste having a predetermined viscosity are arranged at intervals of 6P, and conveyance for moving the dispenser in the X direction parallel to the rib and the Y direction orthogonal to the rib The nozzle in the X direction and at one end of the rib by controlling the nozzle section, the transfer section and the dispenser .
Coating pitch 6 while moving in the forward direction from the other end
The phosphor paste discharged from the nozzle at the same time to the n grooves by P is applied to the surface tension of the paste between the nozzle and the rib.
The first operation of filling so as to pull the twine, the second operation of moving the nozzle in the Y direction by 3P, and the nozzle in the X direction and
While moving in the opposite direction from the other end to the one end of the rib, the phosphor paste simultaneously ejected from the nozzles into the n grooves is moved between the nozzles and the ribs by the surface tension of the paste.
3rd operation of filling by pulling the thread, 3P x nozzle
And a controller that repeats each operation of the fourth operation of moving in the Y direction by (2n−1), and each dryer is such that at least the surface tension of the phosphor paste applied to the groove on the substrate is not generated. Each of the substrate transporters transports the substrate coated with the phosphor paste from the phosphor layer forming device to the adjacent phosphor layer forming device through the dryer, and three types are provided in predetermined grooves on the substrate. The phosphor layer forming system is characterized in that the phosphor pastes of the above colors are applied and dried alternately for each color to form phosphor layers of three colors along the inner surface shape of the groove. It is provided.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION A plasma display panel (PDP) according to the present invention is designed to locally generate an electric discharge between two opposing substrates to excite and emit a phosphor layer partitioned and formed on the substrates. It is the one. this is,
For example, a pair of substrate assemblies 5 as shown in FIG.
It is composed of 0, 50a (for one pixel).

In the substrate assembly 50a, a pair of sustain electrodes X and Y for generating a surface discharge along the substrate surface are arranged line by line on the inner surface of the front glass substrate 11. Each of the sustain electrodes X and Y is a transparent electrode 4 having a wide linear band and made of an ITO thin film.
1 and a narrow strip-shaped bus electrode 42 composed of a metal thin film
Composed of and.

The bus electrode 42 is an auxiliary electrode for ensuring proper conductivity. A dielectric layer 17 is provided so as to cover the sustain electrodes X and Y, and a protective film 18 is deposited on the surface of the dielectric layer 17. Both the dielectric layer 17 and the protective film 18 have translucency.

Next, in the substrate assembly 50,
On the inner surface of the glass substrate 21 on the back side, the sustain electrodes X,
Address electrodes A are arranged so as to be orthogonal to Y. One linear rib, that is, a rib r, is provided between each address electrode A.

Substrate assembly (hereinafter referred to as substrate) 5
At 0, the discharge space 30 is divided into sub-pixels (unit light emitting regions) EU in the line direction by the ribs r, and the gap size of the discharge space 30 is defined.

The upper part of the address electrode A and the rib r
A phosphor layer 28 of three colors of R, G, B for color display is provided so as to cover the wall surface on the back side including the side surface of the.

The rib r is made of low melting glass and is opaque to ultraviolet rays. As a method of forming the rib r, a step of providing an etching mask on the low melting point glass layer in the form of a solid film by photolithography and patterning by sandblasting is used. In this step, the arrangement of the plurality of ribs r formed is determined by the pattern of the etching mask and is parallel to each other as shown in FIG. 8 or meandering as shown in FIG. 9 when viewed from the top surface of the substrate. Alternatively, as shown in FIG. 18, a plurality of ribs r each having a straight center portion and both end portions bent in opposite directions are formed so that one end of each adjacent rib is opened and the other end is closed, and the center portion is Those arranged so as to be parallel to each other are formed.

A pair of sustain electrodes 12 corresponds to one line of the matrix display, and one address electrode A corresponds to one column. The three columns correspond to one pixel (pixel) EG. That is, one pixel EG is composed of three subpixels EU of R, G, and B arranged in the line direction.

The counter discharge between the address electrode A and the sustain electrode Y controls the wall charge accumulation state in the dielectric layer 17. When the sustain pulse is alternately applied to the sustain electrodes X and Y, surface discharge (main discharge) occurs in the sub-pixel EU in which a predetermined amount of wall charge exists.

The phosphor layer 28 is locally excited by the ultraviolet rays generated by the surface discharge and emits visible light of a predetermined color. Of this visible light, the light that passes through the glass substrate 11 becomes the display light. Since the arrangement pattern of the ribs r is a so-called stripe pattern, the portion of the discharge space 30 corresponding to each column is continuous in the column direction across all the lines. The emission colors of the sub-pixels EU in each column are the same.

In manufacturing such a PDP, the phosphor layer is formed by a phosphor layer forming apparatus after the address electrode A and the rib r are provided on the substrate as shown in FIG. In the phosphor layer forming apparatus according to the present invention, the mounting table on which the substrate is mounted is not particularly limited as long as it can detachably fix the substrate substantially horizontally.

The paste-like phosphor (phosphor paste) for forming the phosphor layer is, for example, a mixture of 10 to 50 wt% of each color phosphor, 5 wt% of ethyl cellulose and 45 to 85 wt% of BCA. .

As the red fluorescent substance, for example,
(Y, Gd) BO ₃ : Eu is used, and examples of the fluorescent substance for green include Zn ₂ SiO ₄ : Mn or BaAl ₁₂ O ₁₉ :
Mn is used, and as the blue fluorescent substance, for example, 3 (B
a, Mg) O.8Al ₂ O ₃ ; Eu can be used.

In the nozzle of the dispenser for discharging the paste-like phosphor, the inner diameter of the nozzle is set to be smaller than the rib interval, but the tip of the nozzle is inserted between the ribs. Therefore, the outer diameter of the tip may be larger than the rib interval. For example, when the rib interval is 170 μm, the nozzle has an inner diameter of 100 μm.
m, and an outer diameter of about 300 μm is preferable. In addition, as the nozzle, a multi-nozzle in which a plurality of nozzles (for example, 5 to 30) are arranged at a predetermined coating pitch in a direction orthogonal to the rib may be used. In this case, a plurality of grooves are applied at the same time, which is efficient.

The phosphor supply unit or dispenser for supplying the paste-like phosphor to the groove is composed of a nozzle, a container (syringe) containing the paste-like phosphor connected to the rear end of the nozzle, and the phosphor of the container. A pressure generator that applies pressure to the nozzle to push it out to the nozzle can be used. For this, for example, a commercially available dispenser system (System C type, manufactured by Musashi Engineering Co., Ltd.) can be used.

In the carrying section of the present invention, the nozzle and the mounting table are relatively moved so that the tip of the nozzle moves in three directions of a direction parallel to the rib of the substrate, a direction orthogonal to the rib, and a direction perpendicular to the substrate. Things to move, eg 3-axis robots or 3
A shaft manipulator can be used.

The drive source for driving each axis is a motor,
An air cylinder, a hydraulic cylinder, or the like can be used, but it is preferable to use a stepping motor or a servomotor with an encoder in terms of easiness of control and accuracy.

Further, the control unit for controlling the movement operation of the transfer section and the ejection operation of the nozzle is composed of a microcomputer including a CPU, a ROM, a RAM and an I / O port, and a driver circuit for driving a drive source of the nozzle transfer section. it can. The input unit for setting the control condition of the control unit, for example,
A keyboard, tablet, mouse or the like can be used.

In such a phosphor layer forming apparatus, a substrate having a plurality of ribs formed in parallel on the surface at a predetermined pitch is placed on a mounting table, and the phosphor is moved while the nozzle tip is moved with respect to the substrate. The phosphor layer is applied to the grooves between the ribs by ejecting from the nozzle tip. Here, when the phosphors of different emission colors are applied to the two grooves adjacent to each other, when the phosphors are applied to the adjacent grooves immediately after the phosphors are applied to the one groove, both the phosphors come into contact with each other. May mix due to surface tension and cause color mixing, so after applying the phosphor of the first color to the predetermined first groove and drying the phosphor, the second color is applied to the adjacent second groove. It is preferable to apply the above phosphor.

Various conditions relating to the position and size of the rib, for example, the shape of the rib (linear or meandering), the length of the rib,
Rib height, rib array pitch, number of rib arrays, positions (coordinates) of the coating start point and coating end point on the substrate, and various conditions related to the nozzle, such as nozzle movement speed, nozzle tip and substrate (or rib). The distance to the crest), the discharge amount of the phosphor per hour, and the like are set in advance from the input unit as necessary. Accordingly, the control unit can move the nozzle with respect to the substrate in accordance with the set rib position and size.

If the phosphor layer forming apparatus further includes an optical sensor for detecting a positioning mark provided on the surface of the substrate, it becomes easier to confirm or correct the position of the nozzle with respect to the positions of the substrate and the ribs. preferable. In this case, for example, a CCD camera can be used as the optical sensor.

When an optical sensor is used, a positioning mark is provided in advance on the surface of the substrate so as to correspond to the rib forming position, but this step is preferably performed simultaneously with the rib forming step for efficiency and accuracy.

That is, when the ribs are formed by the printing method, the positioning marks are also formed by the printing method at the same time, and when the ribs are formed by the sandblasting method, the positioning marks are also formed by the sandblasting method at the same time.

The control unit previously detects the positioning mark formed in this way by the optical sensor, reads the coordinates, and determines the position and pitch of each rib on the basis of the positioning mark in the coating step to determine the nozzle. To move
The preset rib position can be modified.

The positioning mark may be provided for each rib, or may be provided for each predetermined number of ribs. Further, when the positioning mark is provided in correspondence with the coating start position and the coating end position, the movement control of the nozzle is accurately performed. The optical sensor may detect the tip of the rib instead of the positioning mark. When detecting the tip of the rib, it is desirable to mix a coloring material such as a black pigment into the material of the rib to form a dark-colored rib to increase the difference in brightness from the groove.

As shown in FIG. 12, the discharge amount Q of the nozzle has a characteristic that it increases as the distance C between the tip of the nozzle and the substrate (or the top of the rib) (hereinafter referred to as clearance) increases. It is preferable to keep the clearance constant.

The clearance C is determined to be an optimum value determined by the viscosity of the pasty phosphor and the content of the fluorescent substance, but is usually 100 to 200 μm. On the contrary, by utilizing this characteristic, the nozzle discharge amount Q may be controlled by the clearance C.

Further, when the paste-like fluorescent material is discharged from the tip of the nozzle between the ribs and applied, once the application is started, the paste-like fluorescent material is slightly displaced from the regular application position even if the nozzle tip is slightly displaced. It has been confirmed that the body surface tension pulls it back to its normal position.

By utilizing this characteristic, the clearance is reduced only at the start of the coating, that is, the discharge amount is reduced, and the coating is started. After a certain period of time, the clearance is returned to the set value, and the discharge amount is returned to the set value. Therefore, the application work can be started smoothly.

Therefore, in the coating process, the starting coating process for coating the phosphor by keeping the distance between the nozzle tip and the substrate at the first distance, and subsequently, the distance between the nozzle tip and the substrate from the first distance. It is preferable that the steady coating step is performed in which the phosphor is applied while being held at the second distance which is also larger.

In addition, an effective display area is set on a part (central portion) of the substrate surface, and an ineffective display area is set on a part (peripheral portion) of the substrate surface adjacent to the effective display area. The starting coating process may be executed in the area and the steady coating process may be executed in the effective display area.

Further, the clearance C changes due to the warp of the substrate and the variation in the height of the rib, and therefore it is necessary to correct it for each substrate. In order to correct the clearance C, the substrate (or the height of the rib) at any point (three points or more) in the substrate is measured, a virtual curved surface (spline curved surface) that connects these is calculated, and a predetermined value is calculated above this. The nozzle tip may be moved with the clearance C of.

Therefore, when the coating device further includes a height sensor for detecting the height from the mounting table at any point on the substrate surface, the phosphor layer forming method can be performed at any three points on the substrate surface. It is preferable to further include a step of detecting the height and a step of setting a virtual curved surface passing through each detected point, and moving the nozzle tip in parallel with the virtual curved surface in the coating step.

In the height sensor, for example, the light of the laser diode is high-frequency modulated and radiated toward the target, and the phase of the reflected modulated wave is compared with the reference wave to measure the distance to the target. A known optical sensor can be used.

[0042]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIGS. 2, 3 and 4 are a perspective view, a plan view and a front view, respectively, showing a 42-inch color PDP phosphor layer forming apparatus, and FIG. 5 is a block diagram of its control circuit. In these figures, a mounting table 51 for mounting the substrate 50 has a substrate positioning pin 91 to 93.
And a suction device (not shown) for sucking and fixing the substrate.

A pair of Y-axis direction transfer devices (hereinafter referred to as Y-axis robots) 52 and 53 are provided on both sides of the mounting table 51, and an X-axis direction transfer device (hereinafter referred to as X-axis robot) 5 is provided.
4 is mounted on the Y-axis robots 52 and 53 so as to be movable in the direction of the arrow Y-Y ', and the Z-axis direction transfer device (hereinafter referred to as the Z-axis robot) 55 is moved to the arrow X-axis robot S4 by the arrow XX'.
It is mounted so that it can move in any direction. The Z-axis robot 55 is equipped with a syringe mounting portion 58 that detachably mounts a dispenser including a nozzle 56 that discharges a paste-like phosphor and a syringe 57 so as to be movable in the arrow ZZ ′ direction. .

The position sensors 59 and 60 for detecting the positioning marks provided on the surface of the substrate 50 are
Each is independently installed on the X-axis robot 54 so as to be movable in the direction of arrow XX ′, and the distance (clearance) C from the tip of the nozzle 56 to the top of the rib and the tip of the nozzle 56 to the phosphor paste surface after coating. The height sensors 61 and 62 for measuring the distance are fixed to the front and rear of the syringe mounting portion 58 with the nozzle 56 interposed therebetween.

The Y-axis robots 52 and 53 convey the X-axis robot 54 by the Y-axis motors 52a and 53a.
The X-axis robot 54 uses the X-axis motor 54a to move the Z axis.
The axis robot 55 is conveyed, and the sensor motors 54b, 54
The position sensors 59 and 60 are conveyed by c.
In the Z-axis robot 55, the Z-axis motor 62 conveys the syringe mounting portion 58.

In FIG. 5, the control unit 80 includes a CPU, R
It incorporates a microcomputer including an OM and a RAM, receives outputs from the keyboard 81, the position sensors 59 and 60, and the height sensors 61 and 62, and outputs the X-axis motor 5
4a, Y-axis motors 52 and 53, Z-axis motor 55a,
The sensor motors 54b and 54c and the air control unit 72 are driven and controlled, and various conditions input from the keyboard 81 and the progress status of the coating operation are displayed by characters or images on the CRT 82.
To display.

Air pressure from an air source (for example, an air cylinder) 70 is applied to an air control section 72 via an air tube 71. The air control unit 72 receives the output from the control unit 80 and applies the air pressure to the syringe 5 via the air tube 73.
7 is applied to control the discharge amount of the nozzle 56 to be constant.

A procedure for forming a fluorescent layer on a 42-inch PDP substrate using this apparatus will be described with reference to the flowchart of FIG. First, the syringe 57 containing the paste-like phosphor 20cc for forming the red (R) phosphor layer is mounted on the syringe mounting portion 58 together with the nozzle 56.

As shown in FIG. 7, a substrate 50 having an ineffective display (dummy) region 50b around the effective display region 50a.
Is mounted and fixed at a predetermined position on the mounting table 51 (step S1).

The substrate 50 is made of a glass plate having a thickness of 3.0 mm, and the effective display area 50a of the substrate 50 is previously
As shown in FIG. 8, the length L = 5 is parallel to the arrow XX ′ direction.
1921 ribs r each having a pitch P of 60 mm, a height H = 100 μm, and a width W = 50 μm are formed.
A positioning mark M1 indicating the coating start position, a positioning mark M2 indicating the center of the substrate, and a positioning mark M3 indicating the coating end position are provided in advance (FIG. 7). Since the substrate 50 has 1920 grooves formed by 1921 ribs r, the R, G, and B phosphors are applied to 640 (1920/3) grooves, respectively.

Therefore, when fixing the substrate, the rib height H, rib width W, number of ribs N, clearance C, nozzle discharge amount Q,
Setting values such as the phosphor paste coating thickness, the nozzle moving speed V, and the coordinates of the height detection areas R1 to R9 (see FIG. 7) are input from the keyboard 81.

Next, when the keyboard 81 is operated, the control unit 80 detects the substrate condition and performs a calculation operation (step S).
2). That is, the X-axis robot 54, the Y-axis robot 52,
By driving 53, the position of the positioning mark M2 is read via the position sensor 59, and the positions of the positioning marks M1 and M3 are read via the position sensor 60.

Then, points P1 to P9 at which the height of the substrate (height from the mounting table 51) in each of the set regions R1 to R9 becomes maximum are detected through the height sensor 61, and the rib starts. Coordinates, coating pitch P, and points P1 to P
A spline curved surface passing through 9 is calculated and set (stored) in the RAM. In this case, the pitch P is the marks M1 and M2.
Is calculated from the distance and the number of ribs N.

Next, an operator attaches a syringe (with a nozzle) containing a red phosphor paste (hereinafter referred to as R phosphor) to the syringe mounting portion 58 as a syringe 57 and a nozzle 56 (step S4), and on the keyboard 81. When the startup operation is performed (step S5), the tip of the nozzle 56 moves to the R phosphor application start position based on the positioning mark M1 and is held at a predetermined height (clearance) (step S6).

Next, the nozzle 56 starts discharging the R phosphor, and at the same time, moves in the direction of the arrow X to start the coating operation of the phosphor paste (step S7). When moving by the length L of one rib, discharging and moving operation (coating work)
Is stopped (steps S8 and S9).

Next, the nozzles 56 have an arrow Y with a pitch of 3P.
Direction, the ejection operation and the movement operation in the arrow X'direction are started (steps S10 to S12). Nozzle 56
Moves by the length L, stops the discharging and moving operations, and moves in the Y direction by the pitch 3P (step S13).
~ S16). Then, the operations of steps S7 to S16 are repeated, and when the number of coatings reaches 640 in step S10 or S15, the work by the R phosphor is completed.

Next, the operator operates the syringe 57 and the nozzle 56.
Is replaced with a paste for green phosphor paste (hereinafter referred to as G phosphor), and the operations of steps S5 to S16 are repeated (steps S17 and S18). 640 by G phosphor
When the application of the book is completed, the syringe 57 and the nozzle 56 are replaced with those for the blue phosphor paste (hereinafter referred to as the B phosphor), and 640 applications of the G phosphor are performed in the same manner as described above (step S19). , S20).

The coating operation is stopped so that the coating end of the phosphor paste 28 in each groove is a predetermined distance d from the end of the rib r, as shown in FIG. This is to prevent the applied phosphor paste from crossing over to the adjacent groove beyond the end of the rib r.
In this case, it is experimentally confirmed that d is effective if it is 0.5 mm or more.

In the coating operation of the above embodiment,
When the nozzle 56 finishes the coating work for one groove, it moves in the arrow Y direction by a preset pitch 3p to perform the coating work for the next groove. Each time, the position sensors 59 and 60 detect the start and end of the rib forming the groove to be applied next, and the nozzle 56 is moved based on the detected start and end positions. You may make it apply. This further improves the accuracy of applying the phosphor paste to each groove. In this case, if the position sensors 59 and 60 cannot detect the start or end of the rib for some reason (for example, partial damage of the rib end), the coating process is not interrupted and is set in advance. The next groove coating operation is performed based on the pitch.

In this way, when the work of forming the R, G, and B phosphor layers along the inner surface shape of the groove between the ribs as shown in FIG. 1 is completed, the X-axis robot 54 moves to the home position (see FIG. At 3, the uppermost side of the mounting table 51 is returned to the position closest to the Y ′ direction). Then, the worker carries out the substrate 50 (step S21). Board 5 carried out
For 0, the phosphor is dried in the next step.

During the above-mentioned coating operation, the tip of the nozzle 56 is always kept at a clearance C = 100 μm from the calculated spline curved surface so that the Z-axis robot 5 has a clearance.
The height is controlled by 5.

The controller 80 monitors the surface height (thickness) of the phosphor paste immediately after coating by the height sensor 62 and the height sensor 61 during the coating work in the directions X and X '. Then, when the monitored thickness deviates from the preset coating thickness to the allowable range or more, the coating work (discharge and movement) of the nozzle 56 is immediately stopped,
A warning (alarm) of "application failure" and the coordinates of the stop position of the nozzle are displayed on the CRT 82. In addition, the control unit 80
The coordinates are stored in the built-in RAM.

After removing the cause of the coating failure (for example, the nozzle outline), the operator replaces the substrate 50 on the mounting table 51 with a new one and performs the coating operation again from the beginning (steps S1 to S1). S21).

This makes it possible to detect the "application failure" of the phosphor paste much earlier than in the conventional case in which the inspection is performed after the R, G, B three-color application and drying steps are completed. Therefore, the efficiency and yield of the phosphor coating operation are improved. In addition, the substrate that "improper application" has occurred is
Since the location (coordinates) of the occurrence is stored, the repair and re-application work becomes easy.

In this embodiment, a plurality of ribs r are independently formed on the surface of the substrate 50 as shown in FIG.
However, as shown in FIG. 9, a rib in which end portions of adjacent ribs are alternately connected may be used. According to this rib shape, the connection portion at the end portion becomes the application end point position of each phosphor, and the string of the phosphor paste can be cut off at this portion.

Further, the rib r is, as shown in FIG.
Adjacent pairs of ribs r are formed on the substrate so that they are separated from each other at one end and adjacent to each other at the other end, and the coating operation is started at the end with wide intervals and at the narrow end. It is preferable to finish. This is because the phosphor paste 28 easily enters the groove at the start of application and does not excessively protrude at the end of application.

In this embodiment, the positioning marks M1 and M
3, the pitch P of the rib r is calculated, but as shown in FIG. 10, the auxiliary positioning mark m is provided for each predetermined number of ribs, and the rib pitch P is set before the coating operation. The mark m may be detected by the position sensor 59 or 60 during the coating operation to correct the pitch P.
The positioning marks M1, M2, M3, and
It is formed at the same time when the rib r is formed at 0.

Before the coating operation, the pitch P is set, the position of the rib to be finally coated is calculated from the pitch P, and the nozzle 56 is moved to the coordinates corresponding to the rib as shown in FIG. Then, the point T may be drawn with a phosphor, the coordinates of the point T and the coordinates of the positioning mark M3 may be respectively detected by the position sensor 60, and the set pitch P may be corrected from the difference ΔL between the distances.

FIG. 13 is a structural explanatory view showing a system using the apparatus shown in FIG. 2, and the R phosphor layer forming apparatus 100 is shown.
The R, drying oven 200a, G phosphor layer forming apparatus 100G, drying oven 200b, B phosphor layer forming apparatus 100B, and drying oven 200C are connected in series via conveyors 300a to 300e. R phosphor layer forming apparatus 100R, G phosphor layer forming apparatus 100G, and B phosphor layer forming apparatus 10
0B is the same device as the phosphor layer forming device shown in FIG. 2, but the syringe 57 contains the R phosphor, the G phosphor, and the B phosphor, respectively.

In such a structure, when 640 R phosphor layers are formed on the surface of the substrate 50 (FIG. 7) by the R phosphor layer forming apparatus 100R, the conveyor 30
0a conveys it to the drying oven 200a to dry it.
The dried substrate 50 is conveyed to the G phosphor layer forming apparatus 100G by the conveyor 300b, and 640 is formed on the surface thereof.
A G phosphor layer of the book is formed.

Further, the substrate 50 is conveyed to the drying oven 200b by the conveyer 300C and dried, and the dried substrate 50 is conveyed to the B phosphor layer forming apparatus 100B by the conveyer 300d, and 640 B fluorescent substances are formed on the surface thereof. A body layer is formed.

Next, the substrate 50 is conveyed to the drying furnace 200C by the conveyor 300e and dried. After that, the substrate 50 is baked by a baking device (not shown), and the ribs 29 are formed.
The R, G, and B phosphor layers 28 along the inner surface shape of the groove between the ribs as shown in FIG. 1 are completed in the groove between.

In the drying ovens 200a to 200c, the paste phosphor filled in the groove of the substrate 50 is 1
The phosphor layer is dried by drying at a temperature of 00 to 200 ° C. for 10 to 30 minutes. Immediately after the application of the phosphor layers of each color, the drying process is performed so that when the previously applied (filled) adjacent phosphors are liquid, the next applied (filled) phosphors contact each other. This is because surface tension may cause mixing and color mixing beyond the ribs, that is, color mixing. That is, after the drying process, the filled paste phosphor becomes a shape along the inner surface shape of the groove between the ribs and loses the surface tension.
In addition, at least one of a hot plate system, a hot air circulation system, and a far infrared system is adopted for the drying furnaces 200a to 200c.

FIG. 14 is a structural explanatory view showing another system using the apparatus shown in FIG. 2. In this embodiment, FIG.
In place of the three drying ovens 200a to 200c of the system shown in FIG. 3, one drying oven 200 is provided, and the conveyors 300a to
Instead of 300e, a transfer robot 300 that transfers the substrate 50 in the directions of arrows AA 'and BB' is provided.

In such a structure, the substrate 50 is transported to the drying furnace 200 by the transport robot 300 and dried each time the phosphors of each color are applied (filled), as in the system shown in FIG.

15 and 16 are a perspective view and a sectional view showing a multi-nozzle as a modified example of the syringe 57 and the nozzle 56 used in each of the above-described embodiments. With this multi-nozzle, 6 for each syringe 57a
The nozzles 56a of the book are arranged in a row at a pitch that is six times the rib pitch P.

When applying the phosphor, the syringe 57
The paste-like phosphor contained in a is simultaneously ejected from the six nozzles 56a. Therefore, six phosphor layers of the same emission color are formed at one time, and the coating work time is shortened to 1/6 as compared with the above-mentioned respective embodiments. Here, the relationship between the rib pitch P, the nozzle pitch P _N, and the movement amount of the nozzles in the Y direction will be described in the case of using a multi-nozzle in which n nozzles are arranged in a row at a pitch P _N for one syringe. Body paste is R, G,
There are 3 types of B).

[A] When the phosphor paste is applied when the nozzle moves in the reciprocating direction: The substrate shown in FIGS. 8, 9 and 18 (in particular, the end patterns of adjacent ribs in FIGS. 9 and 18 are alternately opened. A substrate having a rib) is applicable, and the nozzle arrangement pitch P is
_N is set to P _N = 6P, and the coating operation is performed as follows. (1) First, while moving the nozzle in the X direction from the open guide (the opening of the first groove) of the rib end pattern, the phosphor paste is simultaneously applied to the n grooves at the application pitch 6P. (2) Next, the nozzle is moved by 3P in the Y direction and positioned at the open side (opening of the second groove) of the rib end pattern. (3) Next, while moving in the X ′ direction, a new phosphor paste is applied to the n grooves (in the process up to this point, a total of 2n grooves should be applied with the phosphor paste at a pitch of 3P). become). (4) Next, the nozzle is moved by 3P × (2n−1) in the Y direction and positioned at the opening of the third groove. The above steps (1) to (4) are repeated.

[B] When the phosphor paste is applied when the nozzles are moved in one direction, the substrate shown in FIG. 8 can be applied, and the nozzle arrangement pitch P
_N is set to P _N = 3P, and the coating operation is performed as follows. (1) First, while moving the nozzle in the forward direction (X or X ′ direction), the phosphor paste is simultaneously applied to the n grooves at the application pitch 3P. (2) Next, the nozzle is moved in the opposite direction without applying the phosphor paste to return to the application start position. (3) Next, the nozzle is moved in the Y direction by 3P × n. The above steps (1) to (3) are repeated.

As described above, in the case where the coating operation is performed by the plurality of nozzles 56a at the same time, if the end face of the nozzle tip is perpendicular to the axis of the nozzle even if the nozzle pitch is matched with the rib pitch with high accuracy, Due to the influence of the viscosity and surface tension of the phosphor paste, it is difficult to eject the phosphor paste directly below the nozzle tip, so it is not easy to accurately apply the phosphor paste evenly to the groove corresponding to each nozzle.

Therefore, when using a plurality of nozzles,
As shown in FIG. 19, the nozzle is formed so that the end face of the nozzle tip makes an acute angle θ with the axis of the nozzle, and the nozzle is held so that the axis of the nozzle makes an acute angle α with the substrate 50 in the coating direction. It is preferable that the opening at the tip of the nozzle faces in the direction opposite to the coating direction. In this case, θ is 30 ° to 6
0 ° and α are set to 45 ° to 70 °. As a result, the phosphor paste is surely ejected from each nozzle in a direction opposite to the application direction and the ejection direction is fixed, so that each nozzle can apply the phosphor paste accurately to each desired groove.

The syringe 57a is mounted in the syringe mounting portion 58 (FIG. 4) so that the nozzles 56a are arranged orthogonally to the ribs, but the syringe 57a is rotated in the direction shown by the arrow W in FIG. If the mechanism is provided, it is possible to adjust the coating pitch of each nozzle 56a by rotating the mechanism.

Further, in the present invention, the coating head of a coating device for coating a curtain-shaped paste called a slot coater or a die coater is improved to a head 63 as shown in FIG. It is also possible to do

That is, the head 63 has a longitudinal section shown in FIG.
21, a reserve tank 57b for temporarily storing the phosphor paste and a plurality of phosphor paste ejecting nozzles corresponding to the nozzle 56a shown in FIG. 16 are provided inside the head 63, as shown in FIG. The gap 56b is formed, and the interdigital phosphor paste is discharged from the channel 56b. When applying the phosphor layers of the three colors described above, the heads 63 corresponding to the respective colors are arranged as described above, and the entire application is completed.

[0085]

According to the present invention, the fluorescent substance is ejected from the nozzle moving on the substrate and is applied to the groove between the ribs by simply setting the substrate specifications numerically without using the conventional screen mask. The phosphor layer can be accurately formed on a substrate having an arbitrary size, and the specification of the substrate can be easily changed.

[Brief description of drawings]

FIG. 1 is a perspective view of a main part of a plasma display panel according to the present invention.

FIG. 2 is a perspective view showing an apparatus according to an embodiment of the present invention.

FIG. 3 is a plan view showing an apparatus according to an embodiment of the present invention.

FIG. 4 is a front view showing an apparatus according to an embodiment of the present invention.

FIG. 5 is a block diagram showing a control unit according to the embodiment of the present invention.

FIG. 6 is a flowchart showing the operation of the embodiment of the present invention.

FIG. 7 is a top view showing a substrate of an example of the present invention.

FIG. 8 is an enlarged view of a main part of FIG.

FIG. 9 is an enlarged view of an essential part showing a modified example of the rib of the substrate applied to the present invention.

FIG. 10 is a top view showing a modified example of the substrate applied to the present invention.

11 is an enlarged view showing another method for correcting the rib pitch in the substrate shown in FIG.

FIG. 12 is a graph showing the relationship between the clearance and the phosphor discharge amount in the present invention. .

FIG. 13 is a structural explanatory view showing a system of the present invention.

FIG. 14 is a structural explanatory view showing another system of the present invention.

FIG. 15 is a perspective view showing a modified example of the nozzle of the embodiment of the present invention.

16 is a cross-sectional view of the nozzle shown in FIG.

FIG. 17 is a top view showing the positional relationship between the end portions of the ribs and the application ends of the phosphor paste according to the embodiment of the present invention.

FIG. 18 is a top view showing a modified example of the rib of the substrate to which the present invention is applied.

FIG. 19 is a side view showing a modified example of the tip of the nozzle of the present invention.

FIG. 20 is a perspective view showing a coating head as another modified example of the nozzle of the present invention.

FIG. 21 is a vertical sectional view of the coating head shown in FIG. 20.

22 is a cross-sectional view taken along the line AA of FIG.

[Explanation of symbols]

50 substrates 51 mounting table 52 Y-axis robot 52a Y-axis motor 53 Y-axis robot 53a Y-axis motor 54 X-axis robot 54a X-axis motor 54b Sensor motor 54c Sensor motor 55 Z-axis robot 55a Z-axis motor 56 nozzles 57 syringes 58 Syringe mounting part 59 Position sensor 60 position sensor 61 Height sensor 91 pin 92 pin 93 pin

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI // B05C 5/02 B05C 5/02 (72) Inventor Ryoichi Miura 5950 Soeda, Iriki-cho, Satsuma-gun, Kagoshima Prefecture Kyushu Fujitsu Limited In Electronics (72) Inventor Yasuo Yanagibashi 5950 Soeda, Iriki-cho, Satsuma-gun, Kagoshima Prefecture Kyushu Fujitsu Electronics Co., Ltd. (56) Reference JP-A-8-7762 (JP, A) JP-A-8-115665 (JP) , A) JP 55-32314 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) H01J 9/227 B05D 1/26 B05D 5/06 B05D 7/00 H01J 11/02 B05C 5/02

Claims (6)

(57) [Claims] 1. A plurality of stripes has been kicked set on a substrate
A method of sequentially applying a plurality of phosphors of different emission colors one by one to each groove formed between the ribs of
A plurality of phosphor layer forming apparatuses having nozzles for ejecting phosphor pastes having different viscosities and having predetermined viscosities are prepared, and the first phosphor layer forming apparatus corresponds to the first color phosphor on the substrate. The nozzle from one end to the other end of the groove
The first-color phosphor paste discharged from the nozzle was filled between the nozzle and the groove so as to draw a thread due to the surface tension of the paste, and the first groove was filled. After drying the paste phosphor of the first color at least to the extent that surface tension does not occur,
The second corresponding to the phosphor of the second color adjacent to the first groove
Device for forming another phosphor layer from one end of the groove to the other end
It the second color phosphor paste discharged from the nozzle Hama charging the stringy so by the surface tension of the paste between the <br/> nozzle and the groove, a second filled in the groove of the second A phosphor coating method, characterized in that a color phosphor paste is dried at least to the extent that surface tension is not generated, and filling and drying are alternately repeated for each phosphor paste having a different emission color. 2. A phosphor layer forming apparatus has a plurality of nozzles arranged in parallel, each nozzle is arranged at a rib pitch that is an integral multiple of the number of phosphor pastes of different emission colors, and the same color phosphor paste is ejected at the same time. The phosphor coating method according to claim 1, wherein a plurality of different grooves on the substrate are filled. 3. The phosphor paste filled in the groove between adjacent ribs is deposited along the inner surface shape of the groove in the subsequent drying step to lose the surface tension. Phosphor coating method. 4. A plurality of phosphor layer forming devices that apply phosphors having different emission colors to grooves between adjacent ribs of parallel stripe stripes on a substrate are arranged in series. A mounting table on which the substrate is mounted, a dispenser having a nozzle that discharges a phosphor paste having a predetermined viscosity, and a transport unit that relatively moves the nozzle and the mounting table,
Control the transport unit and dispenser to control the firefly between the nozzle and the groove.
The nozzle is moved from one end to the other end of the groove while discharging the phosphor paste so that the thread is pulled by the surface tension of the optical paste.
And a plurality of dryers for drying the phosphor paste applied between the phosphor layer forming devices and applied to the grooves on the substrate so that at least surface tension does not occur. , Comprising a plurality of substrate transporter for transporting the substrate between each phosphor layer forming device and each dryer, each phosphor layer forming device applies the phosphor paste to the groove corresponding to each color phosphor on the substrate surface. Sequential coating, each dryer dries the phosphor paste applied to the groove at least to the extent that surface tension does not occur, and each substrate transporter dries the phosphor paste coated substrate from the phosphor layer forming device to the dryer. To the adjacent phosphor layer forming device, and sequentially applying and drying phosphor pastes of different emission colors for each color to form a phosphor layer along the inner shape of the groove. Phosphor characterized by Forming system. 5. Phosphors having different emission colors are arranged side by side on a substrate.
Equipped with a plurality of phosphor layer forming devices for coating the grooves between adjacent ribs of the striped ribs , each phosphor layer forming device ejects a mounting table on which a substrate is mounted and a phosphor paste having a predetermined viscosity. A dispenser having a nozzle to perform, a transport unit that relatively moves the nozzle and the mounting table, and a phosphor paste surface between the nozzle and the groove by controlling the transport unit and the dispenser.
It is composed of a control unit that moves the nozzle from one end of the groove toward the other end while discharging the phosphor paste so that the thread is pulled by the surface tension , and further applies the phosphor paste applied to the groove on the substrate. At least one dryer for drying to the extent that surface tension is not generated, and one substrate carrier for transporting a substrate between each phosphor layer forming device and the dryer are provided. The phosphor paste is sequentially applied to the grooves corresponding to the phosphors of each color on the substrate, and the dryer dries the phosphor paste applied to the grooves to the extent that surface tension does not occur at least, and the substrate transporter uses the phosphor paste. The substrate coated with is transferred from one of the phosphor layer forming apparatuses to the other through a dryer, and the phosphor pastes of different emission colors are alternately coated and dried for each color to form a groove. A phosphor layer that conforms to the inner surface shape of Phosphor layers forming system is characterized in that so as to formed. 6. A groove between adjacent ribs of a plurality of stripe-shaped ribs provided in parallel on a plate with a pitch P is 3
A system for forming phosphor layers of different colors, wherein three phosphor layer forming devices for individually applying phosphors of three colors to a plurality of grooves on the substrate are provided with a drier and a substrate between them. Each phosphor layer forming device is arranged with a carrier placed therebetween, and each phosphor layer forming apparatus has a mounting table on which a substrate is mounted and n nozzles for ejecting phosphor paste having a predetermined viscosity.
Dispensers arranged at intervals of, a transport unit for moving the dispenser in the X direction parallel to the ribs and in the Y direction orthogonal to the ribs, and controlling the transport unit and the dispenser so that the nozzle is in the X direction and from one end of the ribs. at the same time the n of grooves in the coating pitch 6P while moving in the forward direction toward the other end portion Bruno
Apply the phosphor paste discharged from the nozzle to the nozzle and ribs.
And a second operation of moving the nozzle in the Y direction by 3P, a nozzle in the X direction and one end from the other end of the rib. Department
At the same time the n of grooves while moving in the opposite direction towards the nozzle
The phosphor paste ejected from the nozzle
A controller that repeatedly performs the third operation of filling the yarn by the surface tension of the paste between them and the fourth operation of moving the nozzle in the Y direction by 3P × (2n−1). Each of the dryers dries the phosphor paste applied to the grooves on the substrate to such an extent that at least surface tension is not generated, and each substrate transporter dries the substrate coated with the phosphor paste to the phosphor layer. The phosphor is transferred from the forming device to the adjacent phosphor layer forming device via a dryer, and the phosphor pastes of three kinds of colors are applied and dried alternately on the predetermined grooves on the substrate for each color in order to form the grooves. A phosphor layer forming system characterized in that phosphor layers of three colors are formed along an inner surface shape.