JP2013208521A - Method for applying coating liquid and method for producing member for display - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an applying method capable of stably applying a film thickness in an effective range adjacent to a non-effective range even to a substrate/base material in which the non-effective range narrows in a display member.SOLUTION: In a method for applying making a nozzle 30 having a gas space 36 and a coating liquid storing part 35 contacting the space and member to be coated face and come closer each other, and forming a coated film by relatively moving the nozzle 30 and the member to be coated while discharging a coating liquid stored in the coating liquid storing part 35 by pressurizing the space by gas controlled to a predetermined discharge pressure, the speed of the movement is continuously deceleratingly controlled and the discharge pressure is continuously decompressively controlled near the completion of applying, a first deceleration period and a second deceleration period decelerating at different accelerations are arranged during the period carrying out the deceleration control, they are switched during the period carrying out the deceleration control, a first decompression period and a second decompression period decompressing at different ratios are arranged during the period carrying out the decompression control, and they are switched during the period carrying out the decompression control.

Description

  The present invention relates to a method for applying a coating liquid when a coating liquid is applied by using a nozzle, such as a glass substrate or a wafer, and in particular, a plasma display panel (hereinafter sometimes abbreviated as PDP), It is used in the field of manufacturing liquid crystal display color filters (hereinafter also abbreviated as LCM), organic EL displays, flexible displays, optical filters, printed circuit boards, integrated circuits, semiconductors, and the like.

When a coating liquid is applied to a substrate using a nozzle such as a glass substrate or a wafer to form a functional surface layer with a predetermined thickness, the nozzle is fixed to the surface of the substrate on which the surface layer is formed. In most cases, the clearance is maintained and the surface of the substrate and the discharge hole of the nozzle are opposed to each other, and the nozzle and the substrate are relatively moved. In many cases, the nozzles used here are formed so that the edges of all the discharge holes face one plane.

  In many cases, as a device for performing such coating, a coating device including a stage having three axes of an X axis, a Y axis, and a Z axis is used. Then, by driving the three axes, the discharge hole surface of the nozzle is brought close to the surface of the substrate on which the surface layer is formed with a predetermined clearance with high precision, and then the substrate and the nozzle are moved relative to each other while the substrate and the nozzle are relatively moved. The surface layer is formed on the surface of the substrate by discharging the liquid. Hereinafter, the PDP technology, which has been developed in recent years and has formed a market, will be described as an example.

  The PDP is large, thin and lightweight, and its structure and light emitting function cause discharge in the discharge space formed between the front plate and the back plate, and this discharge generates ultraviolet rays centered on a wavelength of 147 nm from xenon gas. As a result, the ultraviolet rays excite the phosphor to enable display. Full-color display can be supported by causing the driving circuit to emit light by separately emitting discharge cells in which phosphors emitting red (R), green (G), and blue (B) are separately applied.

An alternating current (AC) type PDP is formed by laminating a front glass plate on which display electrodes / dielectric layers / protective layers are formed and a rear glass plate on which address electrodes / dielectric layers / partition layers / phosphor layers are formed. He-Xe or Ne-Xe mixed gas is enclosed in a discharge space partitioned by a grid-like or grid-like partition. Each of the phosphor layers of R, G, and B includes a phosphor having powdery phosphor particles as a main component, a partition extending in one direction for each color formed on the back plate, or such a partition and It is filled in a concave portion formed like a cross beam by orthogonal auxiliary partition walls. For the phosphor layer, a coating liquid (phosphor paste) containing phosphor powder and an organic component is applied to the above-mentioned barrier ribs, or the concave portions formed in a grid pattern by the barrier ribs and the auxiliary barrier ribs, dried, and fired as necessary. Formed by. In order to manufacture a product having such a structure with high productivity and high quality, a coating technique in which a coating liquid (phosphor paste) is applied in a certain pattern is important.
As a method for applying a coating liquid (phosphor paste) between predetermined partitions, there are a screen printing method and a dispenser method (sometimes called a nozzle method), and in recent years, a dispenser method with little material loss has been attracting attention. .

  The discharge of the coating liquid (phosphor paste) in the dispenser method is performed by applying pressure to the coating liquid in the coating liquid reservoir in the nozzle and pushing it out from the discharge hole.

  As a method of pressurizing the coating liquid in the coating liquid reservoir, a method by connecting the coating liquid reservoir and a pump, etc., and feeding the coating liquid from the pump in a certain amount can be considered, but the coating liquid has a high viscosity. In addition, the pressure loss at the wetted part such as the inside of the nozzle and the pipe becomes large, so the delay in response becomes remarkable, and not only the discharge control of the coating liquid (phosphor paste) at the time of application becomes difficult, The pressure resistance of equipment such as piping connecting the nozzle and the pump must be increased, which is not appropriate because the apparatus becomes expensive.

  For this reason, a coating liquid reservoir and a manifold having a space above the coating liquid reservoir are formed inside the nozzle, and a discharge control gas (compressed air) is supplied to the space so as to be in the coating liquid reservoir. In many cases, a dispenser method is used in which the coating liquid is pressurized and pushed out from the discharge holes.

  FIG. 3 is a schematic diagram showing a coating liquid (phosphor paste) coating method by a dispenser method using this discharge control gas (compressed air). In the dispenser method, a nozzle 30 having a coating liquid reservoir 35 and a space 36 in which the phosphor paste 41 is stored is disposed so as to face the substrate 9 that is a member to be coated. The phosphor paste 41 is discharged from the discharge holes 33 by introducing the compressed air whose pressure is controlled through the pipe 24 connected to the space portion 36 while maintaining the clearance of the paste, and the paste is interposed between the partition walls 37. It is the coating method which fills.

  As a configuration of the coating apparatus in this method, for example, as shown in Patent Document 1, a nozzle, a discharge valve, a discharge control gas source, a pipe connecting a manifold and a discharge valve in the nozzle, a discharge valve and a discharge control gas There are known pipes that connect a source and a controller that controls a discharge valve. In the coating apparatus configured as described above, the discharge of the coating liquid from the discharge hole of the nozzle is performed by operating the discharge valve with a controller so that the space portion located above the coating liquid reservoir in the nozzle and the gas source for discharge control communicate with each other. Thus, the discharge control gas is supplied from the discharge control gas source to the space in the nozzle through the discharge valve and the pipe, and pressure is applied to the coating liquid to push out the coating liquid from the discharge hole. Note that the volume of the space in the nozzle is such that the discharge control gas (compressed air) is supplied to the space after the discharge control gas (compressed air) is supplied to the space for each discharge. In order to make the time until the coating liquid is discharged uniform, it is necessary to keep it constant. Therefore, after discharge, the coating liquid is always supplied to the coating liquid reservoir in the nozzle until the volume of the space reaches a predetermined amount.

  The application of the phosphor paste by such a dispenser method is often a single-wafer intermittent application, and there are a discharge start and a discharge end while a single substrate is applied. In the single wafer intermittent application, the application start part is a discharge start part and the application end part is a discharge end part, so that the relative movement speed, the discharge pressure, and the like are in a transient state. Therefore, it is difficult to maintain the coating film thickness not only in the dispenser method but at the coating start / end part (also referred to as coating end part) uniformly and at a predetermined film thickness value, and various improvements have been made.

  For example, Patent Document 2 discloses a method for eliminating a faint shape, a discontinuous shape, or a subtracted shape at the coating start end and / or end end in single-wafer coating. The change in the coating speed here is related to maintaining the shape of the coating edge, but the actual speed switching causes an acceleration / deceleration area (time) and improves the production efficiency. On the other hand, a large nozzle that completes coating in one scan is used in most cases, and in the case of this large nozzle, the pressure response region (time) at the start and end of coating greatly affects the film thickness. Therefore, at present, it is difficult to maintain the film thickness at the coating end only by changing the coating speed shown in Patent Document 2.

  In Patent Document 3, as a means for maximally reducing the defective film thickness region at the start and end of application, the supply amount of the application liquid from the constant capacity pump to the applicator is increased or decreased step by step. A method is shown in which the coating speed is lower than the coating speed at other times. However, since the application by the dispenser method is performed by directly pressurizing and discharging the coating liquid surface in the space in the nozzle with compressed air, a delay due to the expansion of the supply hose as described in Patent Document 3 occurs. Absent. Therefore, to increase or decrease step by step with the dispenser method is to increase or decrease the discharge pressure step by step. In this case, the discharge amount fluctuates directly, so the coating film thickness also has a step thickness change. Occurs. Further, although the speed is reduced, the movement does not stop, and therefore, a faint shape, a discontinuous shape, a trailing shape, or the like of the coating liquid at the end portion of application is generated.

  In Patent Document 4, as a means for finely adjusting the film thickness profile of the coating film at the coating start portion, the pressure at the time of coating is detected in the path from the constant capacity pump to the applicator, and the detected pressure at the time of coating is detected. A method is shown in which the pressure is controlled so that the corrugated shape becomes a desired shape. However, when this application method was applied to the application end part of the dispenser method, the following problems occurred.

  4 is a pressure time diagram when the pressure waveform is controlled at the application end portion of the dispenser method, and FIG. 5 is a schematic diagram of an image obtained by observing the application end portion of the substrate subjected to the control of FIG. Although precise pressure control was performed as shown in FIG. 4, there was a coating failure near the end of coating, as shown in FIG. 5, the coating thickness was uneven and the coating surface was cut off. This depends on the properties of the coating liquid, but the relationship between the discharge rate and pressure is not constant, and the change (decrease) in the discharge rate increases as the pressure shifts to low pressure. It suggests that constant is not enough.

  Further, an effective area / ineffective area as shown in FIG. 6 is provided on the substrate which is a member to be applied, and the film thickness in the effective area is set to a predetermined value while keeping the application area within the ineffective area at both ends in the application direction. Application is required to be uniform within the value. The effective area / non-effective area is sometimes called a display area / non-display area depending on the object, and high quality is required for the effective area. However, in recent years, from the viewpoint of material efficiency and final product design, in display devices such as televisions, the frame portion outside the display screen has become narrower, and accordingly, it is a member to be coated. In a substrate or the like, the ineffective area provided at the coating end is physically narrowing. In other words, this means that the demand for the coating end film thickness has become stricter. The area at the edge of the substrate has been changed due to “narrowing the frame”, and a defective film thickness portion at the edge of the substrate that has been hidden in the ineffective area in the past has entered the effective area and becomes apparent. It's ugly. Maintaining the coating end film thickness has traditionally required difficult technology, but it is not easy to handle substrates that support this "narrow frame". It is becoming difficult due to physical limitations.

Japanese Patent Publication No. 2002-053297 JP 2001-269612 A Japanese Patent Laid-Open No. 2002-086044 JP 2005-288387 A

The present invention has been made in view of the above, and stably coats the film thickness in the effective area adjacent to the ineffective area even on a substrate whose ineffective area has become narrow due to the narrowing of the product. An object of the present invention is to provide a method of applying a coating liquid to a display member that can be used and has high quality.

  In order to achieve the above object, the present invention provides a gas having a gas space and a coating liquid reservoir that is in contact with the gas space, the nozzle and the member to be coated facing each other, and a gas controlled to a predetermined discharge pressure. By forming the coating film on the coated member by relatively moving the nozzle and the coated member while discharging the coating liquid stored in the coating liquid reservoir by pressurizing the gas space In the application method, near the end of application, the speed of movement is controlled to continuously reduce, and the discharge pressure is controlled to continuously decrease, and the period of deceleration control is reduced with different accelerations. A first deceleration period and a second deceleration period are provided, and are switched in the middle of the period during which the deceleration control is performed, and the first decompression period and the second decompression period during which the decompression control is performed at different rates. Provided, a method of coating the coating liquid and switches in the middle of the period for the pressure reduction control.

  In addition, the switching from the first deceleration period to the second deceleration period and the switching from the first decompression period to the second decompression period are such that the application position by relative movement between the nozzle and the member to be coated is It is preferable to carry out at the boundary position between the effective area and the ineffective area provided on the member to be coated. In the present invention, the effective area is an area range in which good quality is required in the member to be coated, and the non-effective area is an area range in which low quality is allowed compared to the effective area in the member to be coated. is there.

  Moreover, it is preferable to stop the relative movement with the end of the second deceleration period.

  The relative movement during the second deceleration period is preferably performed within the ineffective range.

  Further, it is preferable that the gas space is opened to the atmosphere with the end of the second decompression period.

  Moreover, it is preferable to manufacture the member for a display using the coating method in any one of the said.

  According to the present invention, a nozzle having a gas space and a coating liquid reservoir that is in contact with the gas space is arranged so that the nozzle and the member to be coated face each other, and the gas space is added by a gas controlled to a predetermined discharge pressure. While discharging the coating liquid stored in the paste reservoir by pressing, the nozzle and the member to be coated are moved relatively to form a coating film on the member to be coated, In the vicinity of the end of the application, the speed of movement is continuously reduced and controlled, the discharge pressure is continuously reduced, and the first deceleration period and the second period during which the deceleration control is performed with different accelerations. A deceleration period is provided and is switched in the middle of the period for performing the deceleration control, and a period for performing the decompression control is provided with a first decompression period and a second decompression period for decompressing at different ratios, By switching in the middle of the period during which pressure control is performed, it becomes possible to arbitrarily combine speed and pressure changes in the decelerating and depressurizing region, and coating that achieves good film thickness at the coating end where film thickness control is difficult A method is obtained.

  In addition, the switching from the first deceleration period to the second deceleration period and the switching from the first decompression period to the second decompression period are such that the application position by relative movement between the nozzle and the member to be coated is By performing at the boundary position between the effective area and the non-effective area provided on the member to be coated, the film thickness up to the effective area of the member to be coated can be kept good. Furthermore, the low-speed and low-pressure regions that are difficult to control can be accommodated in the ineffective region of the substrate to be coated having little influence on the quality.

  Further, by stopping the relative movement with the end of the second deceleration period, it is possible to suppress unnecessary drag of the paste at the coating end end.

  In addition, the relative movement in the second deceleration period is performed in the ineffective region, so that the application end edge can be accommodated in the application target member while suppressing unnecessary drag of the paste.

  Further, by opening the gas space to the atmosphere at the end of the second decompression period, it is possible to omit the control of the pressure in the low pressure region where the degree of difficulty is high, so that the coating can be performed with an easy control configuration.

  Further, by applying the coating method of the present invention to the production of a display member, it is possible to provide a coated member that maintains a good film thickness for a display member that requires high quality.

It is the schematic perspective view which showed schematically the coating device used for one Example in the paste coating method of this invention. It is the schematic diagram which showed the structure of the part which concerns on discharge, and the cross-sectional structure of a nozzle of the coating device used for one Example in the paste application | coating method of this invention. It is the schematic diagram which showed the fluorescent substance paste coating method by the dispenser method. It is a time diagram which shows the correlation of the discharge pressure and application | coating speed in pressure control type application | coating. FIG. 5 is a schematic diagram of a coated end state coated surface state of a substrate coated under the conditions of FIG. 4. It is the schematic diagram which showed roughly the effective area / ineffective area provided in a board | substrate. It is a time diagram which shows speed-pressure correlation in the paste application | coating method of this invention. FIG. 3 is a schematic diagram of a coating end state coating surface state of a substrate coated by the coating method of the present invention. 5 is a speed / pressure control chart in the coating method shown in Comparative Example 1. FIG. 10 is a speed / pressure control chart in the coating method shown in Comparative Example 2. FIG. It is a speed pressure control chart figure in the coating method of the present invention. It is another schematic perspective view which showed schematically the coating device used for one Example in the paste coating method of this invention. It is another block diagram which showed the structure of the part which concerns on discharge, and the cross-sectional structure of a nozzle of the coating device used for one Example in the paste application | coating method of this invention.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. However, the present invention is not limited to this.

  First, an overall configuration of a coating apparatus for carrying out the coating liquid coating method according to the present invention, particularly an example of the overall configuration of a coating liquid coating apparatus for an uneven substrate (for example, a member for PDP) will be described. FIG. 1 is an overall perspective view of a coating apparatus 1 according to an embodiment of the present invention, and FIG. 2 is a schematic diagram showing a configuration of a portion related to ejection in the coating apparatus 1 and a sectional structure of a nozzle.

  In FIG. 1, the material 9 to be coated is placed on the table 2 and is adsorbed and fixed by an adsorption device (not shown) provided on the table 2. The table 2 is supported by a θ-axis member 3 (shown by a broken line) that enables rotational positioning with its center as an axis. The θ-axis member 3 is mounted on a Y-axis adjustment unit 4 that enables positioning in the Y direction, and the Y-axis adjustment unit 4 extends along a pair of Y-axis guide rails 4 a and 4 b provided on the X-axis transport unit 5. It moves in the Y direction of the machine base 6. The X-axis transport unit 5 moves in the X direction along a pair of X-axis guide rails 5 a and 5 b provided on the machine base 6. The X direction and Y direction are adjusted to be orthogonal. The X-axis transport unit 5 is a relative movement unit for applying the coating liquid to the substrate 9 and moves the table 2 in the X direction in the application operation.

  The X-axis transport unit performs speed control that can change the moving speed at an arbitrary acceleration at an arbitrary position by precise control of a drive shaft (not shown).

A gate-shaped support base 7 is provided above the center of the machine base 6 so as to pass through the table 2 moved by the X-axis transport section 5 so as to be orthogonal to the X-axis. Z-axis moving portions 8 a and 8 b that move in the direction perpendicular to the surface of the table 2 are provided in the vicinity of both sides in the Y-axis direction on the side surface in the X-axis direction (hereinafter referred to as the downstream side) of the support base 7. The nozzle 30 for discharging the coating liquid is attached to the Z-axis moving parts 8a and 8b with reference to the center in the Y direction of the machine base 6. The nozzle 30 is detachable and is fixed by chucks (not shown) provided on the Z-axis moving portions 8a and 8b so as to be orthogonal to the X direction of the table 2.
With these configurations, the nozzle 30, the table, and the substrate can be moved relative to each other in the XYZ3 directions.

  The nozzle is selected according to the size of the substrate to be coated, and in order to complete the coating with a single coating operation for all the grooves formed on the substrate, the plurality of discharge holes are preferably substantially straight. Arranged and provided. For example, when the substrate to be applied is a back plate of a plasma display, it is preferable to apply a coating liquid containing phosphor powder of any one color of R, G, or B. The discharge holes are provided in a substantially straight line with a number and a pitch corresponding to.

  Here, it is common for the nozzle to complete application to one substrate in one application operation, but in some cases, the number of ejection holes is reduced and application to one substrate is completed in multiple application operations. You may do. That is, it may be a short nozzle or a nozzle having a wider pitch of discharge holes. Further, although the case where the coating liquid of one color is applied has been described in detail, the present invention can also be applied to the case where the coating liquids of R, G, and B colors are applied simultaneously.

  The nozzle 30 shown in FIG. 1 and FIG. 2 is a gas space located above the discharge holes 33 arranged substantially linearly, a coating liquid reservoir 35 serving as a coating liquid reservoir, and a coating liquid reservoir 35. A manifold 34 having a space 36, a coating liquid port 31 serving as an inlet for supplying the coating liquid into the manifold 34, and a gas passage serving as a passage for supplying and discharging a discharge control gas in the space 36. It consists of a mouth 32. It is preferable that the gas passage port 32 is opened above the space portion 36 and is arranged near the end of the space portion 36 in the direction in which the discharge holes 33 are arranged in a substantially straight line.

  A portion relating to replenishment of the coating liquid to the nozzle 30 will be described. The nozzle 30 is connected to a coating liquid port 31 for supplying a coating liquid into the manifold 34, and the opposite end of the piping 13 is connected via an opening / closing valve 12 that controls the supply of the coating liquid. A coating liquid container 11 for storing the coating liquid is connected. The opening / closing valve 12 is controlled to be opened and closed by the controller 40. A pipe 28 for supplying a supply control gas for extruding the coating liquid and replenishing the nozzle 30 is connected to the coating liquid container 11, and the other side of the pipe 28 is discharged via a pressure reducing valve 27. A control gas source 29 is connected. The pressure reducing valve 27 can adjust the supply control gas from the discharge control gas source 29 to a pressure necessary for replenishment of the coating liquid.

  Next, the part which concerns on discharge of the coating liquid from the nozzle 30 is demonstrated. A pipe 24 is connected to a gas passage port 32 that opens into a space 36 in the nozzle 30 and serves as a passage for supplying and discharging the discharge control gas. 22 is connected. The discharge valve 22 is a three-way valve, one of which is connected to a pipe 26 connected to a discharge control gas source 29 via a pressure reducing valve 23, and the other is open to the atmosphere. The pressure reducing valve 23 can adjust the discharge control gas from the discharge control gas source 29 to a pressure necessary for discharging the coating liquid from the nozzle 30. The pressure reducing valve 23 is preferably an electropneumatic converter that can control the pressure steplessly with an electric signal so that pressure adjustment control is easy. The discharge valve 22 can switch whether the space 36 in the nozzle 30 communicates with the discharge control gas source 29 or the atmosphere, and the switching is controlled by the controller 40.

  The number of gas passage ports 32 may be plural instead of one. Preferably, one gas passage 32 is provided at both end portions of the nozzle 30 symmetrically. When installing a plurality of gas passages, it is preferable to configure the piping system so that the discharge control gas passing through the gas passages can be individually controlled.

  In the coating apparatus 1 shown in FIGS. 1 and 2, a single switching valve 22 that is a three-way valve is used as a passage switching means for controlling the supply and discharge of the discharge control gas through the gas passage port. The means may be a plurality of switching valves and is not limited to that shown here. The switching valve used as the passage switching means may be of any structure, but when applying the coating liquid to the substrate, in order to improve the film thickness at the coating end, In order to quickly discharge and stop the coating liquid, it is preferable to have a good response to a command from the controller 40. Moreover, it is preferable that it can withstand the pressure of the discharge control gas for discharging the coating liquid from the nozzle. Furthermore, what has the durability for repeating application | coating is preferable. Further, the pressure reducing valve 23 may be any one that accurately follows a predetermined pressure setting, but preferably one that accurately follows an electrical control command. The pressure reducing valve 23 is preferably one that can withstand the pressure of the discharge control gas and that has durability.

A case where application is performed by the application apparatus 1 shown in FIGS. 1 and 2 will be described.
First, the coating liquid is supplied from the coating liquid container 11 into the manifold 34 of the nozzle 30. Replenishment of the coating liquid to the nozzle 30 is performed by opening the opening / closing valve 12, and after the replenishment is completed, the opening / closing valve 12 is closed.

  At this time, the coating liquid is stored in a predetermined amount so as to leave a space 36 in the manifold 34 of the nozzle 30. The amount of the coating liquid in the manifold 34 is such that the discharge control gas is filled into the space 36 after the discharge control gas is supplied to the space 36 for each discharge, and the coating liquid is applied from the discharge holes 33. In order to make the time to discharge uniform, it is necessary to keep it constant. Therefore, after the coating liquid is discharged, the coating liquid is always supplied to the coating liquid reservoir 35 in the manifold 34 until the volume of the space 36 reaches a predetermined amount. Therefore, the coating apparatus 1 of the present invention preferably has a coating liquid amount detection means 39 for detecting the coating liquid amount in the nozzle 30 and more preferably non-contact in order to prevent contamination of the coating liquid. The non-contact coating liquid amount detection means 39 can be applied to any sensor that can detect non-contact such as laser type, ultrasonic type, weight detection type and the like.

  Next, it moves to substrate mounting. The table 2 is moved to the front side (upstream side) end of the support base 7 in the X-axis direction, and a substrate 9 to be applied is mounted and fixed by an external transfer machine or the like substantially at the center of the table surface. This operation can be performed in parallel with the supply of the coating liquid to the nozzle 30.

  Next, substrate positioning is performed. The table 2 is moved, the position of the substrate 9 is measured by the cameras 17 and 19, the reference groove of the substrate 9 is observed by the camera 18, the center position of the groove is determined, and the table 2 is moved in the Y-axis direction. The position of the reference hole of the nozzle 30 and the reference groove center of the substrate 9 are aligned in the Y-axis direction. The reference hole of the nozzle 30 is measured in advance by the camera 20. The cameras 17, 19, and 18 are attached to a Y 1 transport unit 14, a Y 3 transport unit 16, and a Y 2 transport unit 15 that can move independently in the Y-axis direction of the support base 7. The Y1-Y3 transport unit is adjusted by the pair of guide rails 7a and 7b so that the height from the table surface is constant even when it is moved in the Y direction. A plurality of these cameras may be provided.

  When the substrate positioning is completed, the operation moves to the coating liquid application operation. After confirming that the replenishment of the coating liquid into the manifold 34 of the nozzle 30 is completed (waiting if not completed), and further cleaning the lower surface of the nozzle 30 with the cleaner 10, the table 2 is moved in the X-axis direction. The substrate 9 is moved in the downstream direction from the positioning position of the substrate 9 at a preprogrammed speed, and the moving speed is changed and controlled at a preset position and acceleration. For example, the start of application is a low-speed movement, and then the speed is changed to a high speed at a predetermined acceleration at the speed switching position, the deceleration is started at a predetermined acceleration from the deceleration start position, and the relative movement is stopped at the movement stop position. Such a relative movement between the substrate and the nozzle is performed, and the coating liquid is discharged from the nozzle 30 during the movement, so that the application to the substrate is performed.

  The discharge of the coating liquid from the nozzle 30 is performed by switching the discharge valve 22 so that the nozzle 30 and the discharge control gas source 29 communicate with each other, and a space portion located above the coating liquid reservoir 35 in the manifold 34 of the nozzle 30. By supplying the discharge control gas to 36, the coating liquid is pushed out from the discharge holes 33. Further, the complete stop of the discharge of the coating liquid from the nozzle 30 is performed by switching the discharge valve 22 so that the space portion 36 is opened to the atmosphere, thereby completely stopping the supply of the discharge control gas. The discharge control gas is discharged from 36. It is preferable to perform a change in combination with the speed reduction by continuously reducing the pressure of the pressure reducing valve 23 before completely stopping the discharge of the coating liquid. These switching and continuous decompression are preferably controlled by the controller 40 so as to operate at a predetermined position during the X-axis movement. The pressure reducing means before the complete stop of the discharge may be performed by operation of a plurality of pressure reducing valves and switching valves set to different pressures.

  When the discharge is finished, the coating is finished and the substrate is discharged. The substrate 9 is discharged by moving the table 2 to the downstream end, releasing the adsorbed substrate 9, and taking it out by an external transfer machine or the like. When the substrate 9 is discharged, a series of operations is completed. In the case of continuous application to the substrate, it starts with replenishment of the coating liquid.

  The supply of the coating liquid to the nozzle 30 and the control of the discharge of the coating liquid from the discharge hole 33 are connected to the coating liquid amount detecting means 39, the opening / closing valve 12, the discharge valve 22, and the pressure reducing valve 23 in the nozzle 30. It is controlled by a controller (control unit) 40.

  A series of steps of coating the substrate by the coating apparatus 1 as shown in FIGS. 1 and 2 is a step of replenishing the coating liquid in the manifold 34 of the nozzle 30 and relatively moving the nozzle 30 and the substrate 9. However, it has a process of discharging and applying a coating liquid to the substrate 9. When applying a coating liquid of a predetermined length a plurality of times, such as applying to a single substrate at a time or applying the substrate in a plurality of times, the two steps are alternately performed. It is preferable to repeat. This is because a nozzle that has a coating liquid reservoir and a space above the coating liquid reservoir in the manifold, supplies a discharge control gas to the space, and discharges the coating liquid from the discharge hole at that pressure, Since it is necessary to replenish the manifold with the same amount of coating liquid that was used for the application of the specified length, considering productivity, replenishment of the coating liquid into the nozzle manifold and to the substrate It is preferable to repeat application | coating of alternately.

  Next, a preferable form of the application end portion will be described below. This can cope with a substrate whose ineffective area is narrowed due to the influence of “narrowing the frame”, but there is no problem even if it is applied to a conventional substrate.

  In the coating apparatus 1 shown in FIGS. 1 and 2, the discharge of the coating liquid from the nozzle 30 first completes the replenishment of the coating liquid to the nozzle 30 and closes the open / close valve 12. Then, by switching the discharge valve 22 so that the nozzle 30 and the discharge control gas source 29 communicate with each other, the discharge control gas is supplied to the space portion 36 in the nozzle 30 through the gas passage 32 communicating with the discharge control gas source 29. By supplying gas, the coating liquid is pushed out from the discharge hole 33 and discharged. At this time, the nozzle 30 and the substrate 9 are relatively moved to apply a predetermined length of coating liquid to the substrate 9.

  With respect to the relative movement speed at the application end portion, it is necessary to provide a period during which deceleration control is started continuously from a predetermined position, and the relative movement is controlled to stop at the end of the period during which deceleration control is performed. Is preferred. In the present invention, it is necessary to provide a first deceleration period and a second deceleration period in which deceleration is performed with different accelerations, and to switch to a speed at which the deceleration rate is changed at a predetermined position during deceleration. It is preferable to stop the relative movement.

  Further, the stop of the discharge of the coating liquid from the discharge hole 33 at the application end portion needs to start the pressure reduction control of the pressure reducing valve 23 from a predetermined position and to provide a period for continuously performing the pressure reduction control. This is performed by continuously reducing the supply pressure of the discharge control gas to the space 36 in the space 30.

  Furthermore, it is necessary to provide a first decompression period and a second decompression period in which decompression is performed at different rates in the period in which decompression control is performed, and a space is provided at a predetermined position in the middle of the period in which decompression control is performed. More preferably, the discharge control gas is opened to the atmosphere from the space portion 36 by switching the discharge valve 22 so that the pressure of the portion 36 is released to the atmosphere.

  Although it is preferable as a combination that the position where the deceleration rate is changed and the position where the pressure of the space portion 36 is released to the atmosphere by switching the discharge valve 22 are substantially the same, it is considered that each operation of the coating apparatus has a delay. It is more preferable to finely adjust both positions while observing the thickness of the coated substrate and the state of the coated surface.

  Until the application to the substrate is once completed and the next application is started, the supply of the coating liquid to the nozzle 30, the unloading of the substrate after the application, the next substrate loading, and the positions of the substrate and the nozzle 30 are performed. Perform alignment.

  Thereafter, the next substrate is coated, and thereafter, this operation is repeated to coat a plurality of sheets.

  12 and 13 show another example of a coating liquid coating apparatus for realizing the coating liquid coating method of the present invention. The difference from FIG. 1 and FIG. 2 is that an opening-only valve 42 is provided near the gas passage port 32 of the pipe 24, and the other configurations are the same as those in FIGS. The open-only valve 42 is a two-way valve, one of which is connected to the pipe 24 and the other is opened to the atmosphere. The operation is controlled so as to interlock with the discharge valve 22. That is, when the discharge valve 22 is switched so that the nozzle 30 and the discharge control gas source 29 communicate with each other and the discharge control gas is supplied to the space 36, the opening dedicated valve 42 is closed and the discharge control gas is used. It operates so as not to impede the discharge of the coating liquid from the discharge hole 33. On the other hand, when the discharge valve 22 is switched and the space 36 is opened to the atmosphere, the space 36 is also opened to the atmosphere through the opening dedicated valve 42.

  The preferable form of the application | coating end part using FIG. 12 and FIG. 13 is demonstrated below. This can cope with a substrate whose ineffective area is narrowed due to the influence of “narrowing the frame”, but there is no problem even if it is applied to a conventional substrate.

  In the coating apparatus 1 shown in FIGS. 12 and 13, the discharge of the coating liquid from the nozzle 30 first completes the replenishment of the coating liquid to the nozzle 30 in advance and closes the opening / closing valve 12. Then, by switching the discharge valve 22 so that the nozzle 30 and the discharge control gas source 29 communicate with each other, the discharge control gas is supplied to the space portion 36 in the nozzle 30 through the gas passage 32 communicating with the discharge control gas source 29. By supplying gas, the coating liquid is pushed out and discharged from the discharge hole 33. At this time, the open-only valve 42 is closed and does not hinder the extrusion of the coating liquid. At this time, the nozzle 30 and the substrate 9 are relatively moved to apply a predetermined length of coating liquid to the substrate 9.

  The relative movement speed at the application end portion is preferably controlled to start decelerating from a predetermined position and stop the relative movement at the end of application. Furthermore, it is preferable to switch to a speed at which the deceleration rate is changed at a predetermined position during the deceleration, and then stop the relative movement.

  Further, the stop of the discharge of the coating liquid from the discharge hole 33 at the application end portion is performed by controlling the pressure reducing valve 23 to be depressurized from a predetermined position, and continuously supplying the discharge control gas supply pressure to the space 36 in the nozzle 30. It is preferable to carry out under reduced pressure. Further, at the predetermined position in the middle of the pressure reduction, the discharge valve 22 is switched so that the pressure in the space 36 is released to the atmosphere, and at the same time, the opening dedicated valve 42 is switched, so that However, it is preferable to release the gas for discharge control from the space 36 to the atmosphere in a short time. The open-only valve 42 is controlled to operate simultaneously with the discharge valve.

  It is preferable as a combination that the position at which the deceleration rate is changed and the position at which the pressure in the space 36 is released to the atmosphere by switching the discharge valve 22 and the opening dedicated valve 42 are substantially the same position, but there is a delay in the operation of the coating apparatus. In consideration of the fact, it is more preferable to finely adjust both positions while observing the film thickness state of the coated substrate.

  Since the discharge control gas can be opened to the atmosphere in a short time by the opening dedicated valve 42, the relative movement stop time after changing the deceleration rate can be shortened, which is preferable.

  Here, a two-way valve is used as the opening-only valve 42, but any structure and configuration may be used as long as the opening and closing to the atmosphere can be switched. For example, one of the three ports of the three-way valve may be closed and used as the same function as the two-way valve. The open-only valve is preferably selected in consideration of the linkage with the discharge valve 22 and the ease of control. However, like the discharge valve, a valve having good responsiveness to a command from the controller is preferable. It is preferable that it can withstand this pressure and has durability.

  Until the application to the substrate is once completed and the next application is started, the supply of the coating liquid to the nozzle 30, the unloading of the substrate after the application, the next substrate loading, and the positions of the substrate and the nozzle 30 are performed. Perform alignment.

  Thereafter, the next substrate is applied, and thereafter, this operation is repeated to apply to a plurality of substrates.

  In the coating apparatus 1 shown in FIG. 1, FIG. 2, FIG. 12, and FIG. 13, the size of the discharge hole 33 of the nozzle 30 is determined depending on the width of the coating liquid applied and the amount of the coating liquid applied. What is necessary is just to select, and in the case of application | coating of the coating liquid especially to an uneven | corrugated board | substrate (for example, member for plasma display panels), it is preferable to set between 10 micrometers and 500 micrometers. The shape and number of the ejection holes 33 are not particularly limited, and may be any shape depending on the purpose of application. For example, when the coating liquid is discharged in the form of a sheet, the discharge opening may have a shape having an opening (slit) that is long in the width direction of the nozzle instead of the discharge hole.

  Up to now, the case where one kind of coating liquid is applied to the stripe-shaped recess formed on the surface of the substrate has been described in detail, but the present invention is also applicable to the case of simultaneously applying phosphors of three colors such as red, blue and green. The present invention can be applied, and can also be applied to a case where the material is applied to a lattice-shaped recess formed on the surface of the material to be coated.

  As coating conditions that can be used, the coating speed may be any speed, but is preferably 0.1 to 10 m / min, and more preferably 0.5 to 8 m / min.

  Next, according to the embodiment of the present invention, an example in which a coating liquid is applied to a display member, particularly a plasma display back plate will be described.

Example 1
The plasma display back plate, which is a single-wafer substrate, has 3097 ribs with a size of 990 × 600 mm, a height of 0.12 mm and a top width of 0.05 mm on the coated surface, with a pitch of 0.3 mm. Therefore, the distance between adjacent ribs (groove width) was 0.25 mm and the number of grooves was 3096. The coating liquid used was a phosphor paste containing a green phosphor powder having a viscosity of 50 Pa · s.

  As the coating device for coating on the substrate, the coating device 1 and the nozzle 30 according to the present invention shown in FIGS. 12 and 13 were used.

  The nozzle 30 has a hole diameter of 0.12 mm, a number of holes of 1032 holes, and discharge holes 33 having a hole pitch of 0.9 mm arranged in a substantially straight line. The width of the nozzle 30 in the arrangement direction is 1000 mm, and the material is The one made of stainless steel (SUS304) was used. The gas passage 32 serving as a passage for supplying and discharging the discharge control gas into the manifold 34 is a cylindrical one having an inner diameter of 5 mm. Further, the coating liquid port 31 for replenishing the coating liquid was a cylindrical one having an inner diameter of 8 mm.

  The piping 24, the piping 25, the piping 26, and the piping 28 that are connected to the gas passage port 32 of the nozzle 30 and connect the nozzle 30 and the gas source 29 for discharge control are all nylon tubes having an inner diameter of 6 mm. The length of the pipe 24 was 700 mm. Compressed air was used as the discharge control gas.

  The discharge valve 22 that switches between discharge / exhaust in each application during the application a plurality of times was an electromagnetic valve that functions as a three-way valve. For the open-only valve 42, a three-way valve of the same type as that of the discharge valve 22 is selected in consideration of the interlocking of the operation, and one port is closed to use a structure that functions as a two-way valve. The pipe 24 was branched near the gas passage 32 and connected to the open-only valve 42.

  The pressure applied to the nozzle 30 to discharge the phosphor paste as the coating liquid was set to a pressure of 0.85 MPa by the pressure reducing valve 23. In this case, as the pressure reducing valve 23, an electropneumatic converter capable of controlling pressure setting by an electrical signal was used. A continuously changing electrical signal from the controller was applied to the electropneumatic converter to perform a predetermined pressure reduction. By switching the discharge valve 22 and the opening dedicated valve 42 during the decompression, the pressure in the space 36 in the nozzle 30 was released to the atmosphere.

  The coating liquid container 11 is provided with compressed air adjusted to a pressure of 0.35 MPa by the pressure reducing valve 27. Moreover, the opening / closing valve 12 for controlling supply of the coating liquid from the coating liquid container 11 to the nozzle 30 is a diaphragm valve.

  The phosphor paste 41 in the manifold 34 of the nozzle 30 is managed so that the liquid level is 25 mm from the discharge hole 33. Therefore, after the phosphor paste is discharged from the nozzle 30, the phosphor paste is replenished to the nozzle 30 by controlling the opening / closing of the opening / closing valve 12 until the liquid level becomes 25 mm.

  Under the above-described conditions, the application apparatus 1 shown in FIGS. 12 and 13 applies the application while controlling the pressure and the relative movement speed of the space 36 in the nozzle 30 with the controller 40 so as to be the chart of FIG. The conditions were adjusted. Here, the position where the discharge pressure is released to the atmosphere and the position where the coating speed is switched toward deceleration stop (point E in FIG. 11) are set to positions corresponding to the groove schematic diagram of FIG. As a result of changing the setting position appropriately input to the controller and adjusting the conditions while changing the application speed and the discharge pressure, finally, in the application end portion, under the correlation between the application speed and the pressure as shown in FIG. A uniform coated surface as shown in the schematic diagram of FIG. 8 was obtained. Under these conditions, coating was performed on 200 substrates. During the application of 200 sheets, the state of the application surface in the vicinity of the application end portion of the substrate was checked with the cameras 17 to 19 provided in the application apparatus 1 and the visual observation. It was not present, and a good coated surface was obtained.

When 200 substrates on which the phosphor paste was applied were dried, a substrate in which a phosphor layer was formed in the recesses formed by the partition walls was obtained. The phosphor layer was irradiated with an ultraviolet lamp having a wavelength of 254 nm to cause the phosphor layer to emit light, and the light emission state was visually confirmed one by one. It was confirmed that light was emitted uniformly and there were no coating spots.
Comparative Example 1
Next, application to the substrate was performed while setting and controlling the pressure and relative movement speed of the space 36 in the nozzle 30 with the controller 40 so as to be the chart of FIG. 9. The substrate, the coating liquid, the hole diameter, the number of holes, the hole pitch, the gas passage port, the coating liquid port, the discharge valve, the pressure reducing valve, the open-only valve, etc. in the nozzle 30 are the same as those in the coating apparatus 1 in FIGS. Although used, the pressure of the pressure reducing valve 23 was kept constant, and control was performed to release the pressure of the space portion 36 in the nozzle 30 to the atmosphere by switching between the discharge valve 22 and the opening dedicated valve 42.

  Since the pressure from the discharge valve 22 and the opening dedicated valve 42 was released to the atmosphere, the pressure was natural exhaust. Although the combination of the decompression start position and the deceleration start position was changed in various ways, the movement speed and the change in pressure were different from each other, and the condition for finally obtaining a constant film thickness could not be found. When the application end portion of the applied substrate was observed in detail, the application was interrupted because the paste, which was the coating liquid, had a faint shape, a discontinuous shape, or a trailing shape, which was defective.

When the substrate coated by this method was dried and the substrate with the phosphor layer formed in the recesses was caused to emit light, the substrate was not uniformly coated and formed in the predetermined groove, resulting in a defective product.
Comparative Example 2
Next, application to the substrate was performed while setting and controlling the pressure and relative movement speed of the space 36 in the nozzle 30 with the controller 40 so as to be the chart of FIG. Note that the substrate, the coating liquid, the hole diameter, the number of holes, the hole pitch, the gas passage port, the coating liquid port, the discharge valve, the pressure reducing valve, etc. in the nozzle 30 are the same as those in the coating apparatus 1 in FIGS. The pressure of the valve 23 was changed stepwise. The pressure in the space 36 in the nozzle 30 was not released to the atmosphere by switching the discharge valve 22 and the opening-only valve 42.

  As a result, by controlling the pressure stepwise, the amount of paste discharged was also stepwise, and band-like spots were generated on the substrate. Also, since the speed is reduced but the movement is not stopped, the coating liquid at the end of coating has a faint shape, a discontinuous shape, or a shape with a trailing edge, etc. Was not found, so application was interrupted.

When the substrate after application was dried and the substrate with the phosphor layer formed in the recesses was caused to emit light, light and dark spots were formed in a band shape, and it was not uniformly formed in the groove, It became defective.
Comparative Example 3
Next, the application | coating to a board | substrate was implemented under speed-pressure control shown in FIG. The substrate, the coating liquid, the hole diameter, the number of holes, the hole pitch, the gas passage port, the coating liquid port, the discharge valve, the pressure reducing valve, the open-only valve, etc. in the nozzle 30 are the same as those in the coating apparatus 1 in FIGS. Was used.

  As a result of controlling the pressure to the end without releasing the pressure to the atmosphere, as shown in FIG. 5 described above, a faint shape, a discontinuous shape, etc. of the paste as the coating liquid occur, and a constant film thickness is obtained. Application was interrupted because the required conditions could not be found.

  When the substrate after application was dried and the substrate with the phosphor layer formed in the recesses was allowed to emit light, it was not uniformly applied and formed in the predetermined groove, resulting in a defective product.

  The present invention can be applied not only to a plasma display panel coating apparatus but also to a liquid crystal display color filter coating apparatus, and its application range is not limited thereto.

DESCRIPTION OF SYMBOLS 1 Coating device 2 Table 3 (theta) axis | shaft member 4 Y-axis adjustment part 4a, 4b Y-axis guide rail 5 X-axis conveyance part 5a, 5b X-axis guide rail 6 Machine base 7 Support stand 7a, 7b Guide rail 8a, 8b Z-axis movement Section 9 Substrate 10 Cleaner 11 Coating liquid container 12 Opening / closing valve 13 Pipe 14 Y1 transport section 15 Y2 transport section 16 Y3 transport section 17 Camera 18 Camera 19 Camera 20 Camera 22 Discharge valve (discharge / exhaust switching valve)
23 Pressure reducing valve (electro-pneumatic converter)
24 Piping 25 Piping 26 Piping 27 Pressure reducing valve 28 Piping 29 Discharge control gas source 30 Nozzle 31 Coating liquid port 32 Gas passage port 33 Discharging hole 34 Manifold 35 Coating liquid reservoir 36 Space part 37 Partition 39 Coating liquid amount detecting means 40 Controller 41 Phosphor paste 42 Open-only valve

Claims (6)

A nozzle having a gas space and a coating liquid reservoir that is in contact with the gas space, wherein the nozzle and the member to be coated are arranged to face each other, and the gas space is pressurized with a gas controlled to a predetermined discharge pressure, thereby applying the coating liquid. A coating method for forming a coating film on the coated member by relatively moving the nozzle and the coated member while discharging the coating liquid stored in the reservoir, The movement speed is continuously decelerated, the discharge pressure is continuously depressurized, and a first deceleration period and a second deceleration period for decelerating with different accelerations are provided in the period during which the deceleration control is performed. The period during which the deceleration control is performed is switched, and the period during which the decompression control is performed is provided by providing a first decompression period and a second decompression period during which the decompression control is performed at different rates. Coating solution method for coating, characterized in that the switched. In the switching from the first deceleration period to the second deceleration period and the switching from the first decompression period to the second decompression period, the coating position by the relative movement of the nozzle and the member to be coated is the coating target. 2. The coating liquid coating method according to claim 1, wherein the coating is performed at a boundary position between an effective area and an ineffective area provided on the member. 3. The coating liquid application method according to claim 2, wherein the relative movement is stopped with the end of the second deceleration period. The method for applying a coating liquid according to claim 3, wherein the relative movement in the second deceleration period is performed within the ineffective range. 5. The coating liquid coating method according to claim 4, wherein the gas space is opened to the atmosphere with the end of the second decompression period. A display member is manufactured using the coating method according to claim 1, wherein the display member is manufactured.

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