WO2009136429A1

WO2009136429A1 - Masking device and plasma display panel manufacturing system equipped with the same

Info

Publication number: WO2009136429A1
Application number: PCT/JP2008/001181
Authority: WO
Inventors: 憲亮徳永; 友彦村瀬
Original assignee: 日立プラズマディスプレイ株式会社
Priority date: 2008-05-09
Filing date: 2008-05-09
Publication date: 2009-11-12

Abstract

A device (40) is used for masking, at the time of sticking a substance onto the surface of an object (10). The device has belt-like masks (41, 42) extending across an operation area in which an object to be masked is disposed, and a pair of forward/reverse rotatable rollers (45A, 45B), which are disposed on the both sides of the extending direction (M2) of the masks (41, 42) across the operation area and wind the masks (41, 42). The rotating direction of the rollers (45A, 45B) is switched to reciprocate the masks (41, 42).

Description

Masking apparatus and plasma display panel manufacturing system having the same

The present invention relates to an apparatus for performing masking for attaching a substance to a surface of an object except for a part thereof, and a plasma display panel manufacturing system.

When a film is formed on the surface of an object so that a part of the surface is removed by various methods such as spray coating, vapor deposition, vapor deposition, etc., a plate-shaped mask on the surface of the object where the material of the film material does not adhere Masking covered with (shielding body) is performed. In general, the mask has a shape corresponding to the masking area to be shielded. In the mass production of industrial products, one mask is repeatedly used for a plurality of times of film formation in the case where a film is sequentially formed on a large number of workpieces to be formed. Then, the film formation is periodically stopped, and cleaning for removing a substance attached to the mask or mask replacement for replacing the used mask with an unused mask is performed.

A thermal spraying masking device having an endless belt as a mask is known (Patent Document 1). In the disclosed apparatus, the endless belt is guided by a plurality of pulleys so as to circulate and move along a plane including the conveying direction of the object to be sprayed, and passes through a spraying position for receiving spraying and a retreating position for cleaning. The sprayed material adhering to the endless belt at the spraying position is removed by the scraper at the retracted position. That is, in this apparatus, the endless belt is automatically cleaned when it passes the retracted position.
Japanese Patent Laid-Open No. 10-8233

Masking with a belt (strip mask) that is longer than the object to be masked has the advantage that other parts of the belt can be cleaned while masking using part of the belt. In order to reduce belt consumption, it is advantageous to lengthen the belt. However, in an apparatus that circulates an endless belt, if the belt is lengthened, the belt guide mechanism becomes complicated and the apparatus becomes large. In addition, an endless belt having a good seam without protrusions or steps that damage an object is expensive.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a masking apparatus that can clean the mask without pausing the masking and prolong the life of the mask. Another object is to provide a manufacturing system suitable for a masking process in mass production of plasma display panels.

A masking device that achieves the above object is a device for masking to attach a substance to a surface of an object except for a part thereof, and is a belt-like mask extending across a work area where an object to be masked is placed And a pair of forward and reverse rotating rollers that wind the mask on both sides of the working area in the extending direction of the mask. The masking device reciprocates the mask by switching the rotation direction of the pair of rollers. Since the mask is arranged in a roll form in which a pair of rollers are wound, the length of the mask can be made sufficiently longer than the distance between the rollers. If the mask is lengthened, the use frequency per unit length of the mask is reduced, so that the life of the mask is extended.

The mask can be cleaned outside the work area. A means for automatically cleaning may be assembled to the masking device, or cleaning may be performed using a cleaning device separate from the masking device. When assembling means for cleaning, it is desirable to dispose the means on both sides of the work area and wind it up with a roller after cleaning regardless of the moving direction of the mask.

In a preferred embodiment, the position of the mask in the width direction of the mask in the work area is variable, so that the use of the masking apparatus is diversified.

A manufacturing system that achieves the above object is a system that is used in a process of partially attaching a layer forming material to the surface of a substrate in the manufacture of a plasma display panel, and injects the layer forming material downward from an injection port. An apparatus, a transfer device that transfers the substrate in one direction and places it in a work area below the injection port, and masking that partially hides the surface of the substrate arranged in the work area from the injection port Device. The masking device includes a strip-shaped mask extending across the work area along a direction intersecting the substrate transport direction, and a pair of winding the mask on both sides of the mask extending direction with respect to the work area And a roller capable of forward and reverse rotation, and the mask is reciprocated by switching the rotation direction of the pair of rollers.

It is a perspective view which shows the structure of the plasma display panel manufacturing system provided with the masking apparatus which concerns on embodiment of this invention. It is a figure which shows typically the movement path | route of the 1st mask in the said masking apparatus. It is a flowchart which shows the outline | summary of the mask movement control in the said masking apparatus.

The masking apparatus exemplified as an embodiment of the present invention is a facility for manufacturing a plasma display panel. A plasma display panel is a device used for displaying television images and computer output, and is composed of a pair of glass plates each having an electrode arranged thereon.

Referring to FIG. 1, a system 100 for manufacturing a plasma display panel is used in a process in which a layer forming material is partially dispersed and adhered to the surface of a substrate 10 to be processed later to be a glass plate. Specifically, the layer forming material is a powder of magnesium oxide crystals, and is dispersed in order to improve gas discharge characteristics. Since the effect of spreading the magnesium oxide crystals is not directly related to the present invention, the description thereof is omitted here. For example, Japanese Patent Application Laid-Open No. 2008-91086 describes the effect of spraying magnesium oxide crystals.

The system 100 is for spraying the layer forming material by transporting the substrate 10 in one direction (hereinafter referred to as the first direction) M1 and the injection device 20 having the nozzle 21 that injects the layer forming material downward. A transport device 30 disposed in the work area and a masking device 40 that partially hides the surface of the substrate 10 disposed in the work area from the ejection port of the nozzle 21 are provided. The working area is a space in a predetermined range in front of the nozzle 21 with respect to the ejection port, and is a place where the substrate 10 to be ejected and a mask for masking should be arranged. In the example, since the nozzle 21 faces downward, the work area is located below the injection port. The injection device 20 includes a material tank and an injection pump (not shown) and is called a spray gun. The exemplified transfer device 30 includes a belt conveyor that horizontally transfers the substrate 10 and a lift mechanism 35 (see FIG. 2) that moves the substrate 10 up and down within the work area. The

belts

31 and 32 for horizontal conveyance are intermittently driven so that the substrate 10 stays in the work area for a predetermined time. In the figure, the substrate 10 placed in the work area and lifted up, the substrate 10 placed in the work area by the next belt drive, the substrate 10b carried out of the work area by the previous belt drive, A substrate 10a carried out of the work area by belt driving is depicted. The sizes of the

substrates

10, 10a, 10b correspond to, for example, a screen size of 50 inches diagonal or more. The masking device 40 is configured as described in detail below.

The reason why masking performed by the masking apparatus 40 is necessary is mainly to increase the yield of a scribe process in which unnecessary portions of the substrate 10 are removed or divided after the layer forming material is dispersed. In order to improve the handling state of the substrate 10 at the time of scribing, it is necessary to prevent the powder from adhering to the scribe line and its vicinity on the substrate 10. The position of the scribe line defined on the substrate 10 depends on the screen size of the plasma display panel to be manufactured. The masking device 40 is configured to be able to change the mask arrangement position in the work area so that it can be used for manufacturing a plurality of types of plasma display panels having different screen sizes.

The masking device 40 includes first and second belt-like masks 41 extending away from each other so as to horizontally traverse the work area along a second direction M2 that intersects the first direction M1 perpendicular to the transport direction of the substrate 10. , 42, two pairs of forward and

reverse rollers

45A, 45B, 46A, 46B around which the first and

second masks

41, 42 are wound on both sides of the work area in the second direction M2, and the work area And third and fourth belt-

like masks

43 and 44 that extend along the first direction M1 apart from each other and are distributed outside the work area to one side and the other side in the second direction M2 with respect to the work area. Two pairs of forward and reverse rotating

rollers

47A, 47B, 48A, 48 are wound around which the third mask 43 is wound on one side of the second direction M2 of the work area and the fourth mask 44 is wound on the other side. When provided with a pair of washers 50A for cleaning a total of four

masks

41, 42, 43, 44, and 50B. Further, the masking device 40 includes a driving mechanism (not shown) including a motor that rotates a total of four pairs of rollers, and a controller (not shown) that controls the driving mechanism and the

washing machines

50A and 50B.

The first mask 41 is stretched above the substrate 10 disposed in the work area by a pair of

pulleys

61 and 62 that rotate about an axis parallel to the first direction M1. The second mask 42 is stretched above the substrate 10 by a pair of

similar pulleys

63 and 64. The third mask 43 is stretched above the substrate 10 disposed in the work area by a pair of

pulleys

71 and 72 that rotate about an axis in a direction inclined with respect to the second direction M2 in the horizontal plane and 90. It is twisted and guided to the

rollers

47A and 47B for winding. The fourth mask 44 is stretched above the substrate 10 by a pair of

pulleys

73 and 74 arranged symmetrically with respect to the

pulleys

71 and 72 and twisted 90 degrees to guide the

rollers

48A and 48B for winding. Is done. These four

masks

41, 42, 43, and 44 constitute a square mask in the work area.

Each of the

masks

41, 42, 43, and 44 has a length of, for example, 10 times or more the path length between the rollers of the corresponding winding roller pair, and is wound around the roller pair in a roll shape. The mask is sent out from the roll of one roller of the roller pair, and at the same time, the mask is wound up by another roller. At this time, only the roller on the winding side may be driven to drive the roller on the sending side, or both may be driven in synchronization. In any case, it is desirable to apply an appropriate tension so that the mask does not loosen. When the delivery reaches the maximum, the rotation of the roller pair is reversed and the mask is delivered in the opposite direction. The mask reciprocates along a predetermined path as the roller pair is normally reversed.

In the state of rotation of the roller pair at a certain time shown in FIG. 1, the roller 45A sends out the first mask 41 and the roller 45B takes up, and the roller 46A sends out the second mask 42 and the roller 46B takes up. The roller 47A sends out the third mask 43 and the roller 47B winds up, and the roller 48A sends out the fourth mask 44 and the roller 48B takes up. That is, the movement direction is opposite between the first mask 41 and the second mask 42 that are parallel to each other in the work area, and between the third mask 43 and the fourth mask 44 that are parallel to each other in the work area. But the direction of movement is the opposite. However, the present invention is not limited to this, and the relative relationship in the movement direction of the four

masks

41, 42, 43, 44 can be arbitrarily determined.

The mask movement includes an intermittent movement in which the mask is stationary while the layer forming material is being sprayed (hereinafter referred to as work) and a continuous movement in which the mask is moved during the work. Intermittent movement is preferred when the mask is brought into close contact with the substrate 10 in order to increase the masking accuracy. In the case of adopting continuous movement, it is desirable not to bring the mask and the substrate 10 into close contact.

The mask arrangement position in the work area is changed by the horizontal movement of the first and

fourth masks

41 and 44. The

pulleys

61 and 62 for guiding the first mask 41 are supported so as to be movable in the axial directions thereof, and the

pulleys

73 and 74 for guiding the fourth mask 44 are supported so as to be movable in the second direction M2. The substrate 10a depicted in FIG. 1 is dispersed in a masking state in which the first mask 41 is closest to the second mask 42 and the fourth mask 44 is closest to the third mask 43 within the movable range. It has the layer 19a formed by. Further, the substrate 10b is formed by spraying in a masking state in which the first mask 41 is furthest away from the second mask 42 and the fourth mask 44 is furthest away from the third mask 43 within the movable range. It has a layer 19b. However, the first and

fourth masks

41 and 44 are not necessarily arranged at the end of the variable range, and can be arranged at any position within the variable range. The movement of the first mask 41 and the movement of the fourth mask 44 can be performed independently. The movable range is appropriately selected according to the application of the masking device 40. In addition to the first and

fourth masks

41 and 44, the positions of the second and

third masks

42 and 43 can be made variable, thereby making the mask arrangement more diverse.

The material of the

masks

41, 42, 43, 44 may be metal or resin as long as it can withstand repeated use. The thickness needs to satisfy the condition that it can be rolled and that plastic deformation does not occur when guided by a pulley. Preferred examples of the

masks

41, 42, 43, 44 include stainless steel (SUS304, SUS316, etc.) tapes having a thickness of about 0.05 to 0.5 mm.

The portions used for masking in each of the

masks

41, 42, 43, and 44 are cleaned by the cleaning machine 50A or the cleaning machine 50B before winding. Each of the

cleaning machines

50A and 50B disposed on both sides of the work area in the second direction M2 has a liquid tank 51 for storing a cleaning liquid (for example, a nitric acid solution) and a moving path of each of the

masks

41, 42, 43, and 44. Is provided with a path switching mechanism 53 for switching between a winding path and a delivery path, and a blower 54 as means for removing the cleaning liquid from the cleaned mask.

The path switching mechanism 53 of the

cleaning machines

50A and 50B is a mechanism for moving up and down a single pulley or a plurality of pulleys that guide the

masks

41, 42, 43, and 44, respectively. As shown in FIG. 2 as a representative movement path of the first mask 41, each path switching mechanism 53 causes a feeding path R1 that does not pass through the cleaning liquid 52 and a winding path R2 that passes through the cleaning liquid 52. Switching takes place. In FIG. 2, the delivery path R1 is set by the path switching mechanism 53 of the cleaning machine 50A for the part of the mask 41 that is sent to the work area, and the part of the mask 41 that passes the work area is cleaned. The winding path R2 is set by the path switching mechanism 53 of 50B. Further, the blower 54 of the wind-up side cleaning machine 50B blows air onto both the front and back surfaces of the portion of the mask 41 that passes through the cleaning liquid. The blower 54 of the washing machine 50B on the delivery side is at rest. When the feeding and winding are switched as described above, the state of each path switching mechanism 53 is also switched.

If attention is paid to each of the first and

second masks

41 and 42, the delivery path R1 is set on one of the two

cleaning machines

50A and 50B and the winding path R2 is set on the other as shown in FIG. On the other hand, paying attention to the third mask 43, in one of the cleaning machines 50A, the delivery path R1 is set for the part to be sent out of the mask 43, and the take-up path R2 is set for the part to be taken up. The Further, paying attention to the fourth mask 44, in one of the cleaning machines 50B, a delivery path R1 is set for a portion to be sent out of the mask 44, and a take-up path R2 is set for a portion to be wound.

In the masking device 40, movement control is individually performed for the four

masks

41, 42, 43, and 44. The flowchart in FIG. 3 shows the procedure for switching the rotation direction of the roller pair corresponding to one mask and switching the movement path in the cleaning machine.

The controller of the masking device 40 checks the mask winding state in the roller pair corresponding to each mask when the masking device 40 starts operation. For example, for the mask 41, the state of the pair of

rollers

45A and 45B is checked. One of the pair of rollers is first determined as the first and the other is determined as the second, and the controller first checks whether or not the first roller can be sent out (# 11). The state that can be sent out is a state in which a mask is wound around the roller. This state can be detected by a method in which the size of the roll diameter is detected by a sensor or the amount (time, length, or roller rotation speed) is counted at the time of feeding.

If the first roller can be sent out, the mask moving path in the cleaning machine between the first roller and the work area is set as the sending path R1, and the cleaning machine between the second roller and the work area is in the cleaning machine. The path switching mechanisms 53 of the two

cleaning machines

50A and 50B are controlled so that the mask movement path is the winding path R2 (# 12). Thereafter, forward rotation of the roller pair is started (# 13). Here, the positive rotation is a rotation in which the first roller sends out the mask and the second roller winds up the mask. The positive rotation is intermittent or continuous rotation as described above. If the first roller is not ready to be fed, the controller executes a process of step number # 15 described later.

When the delivery by the first roller reaches the limit or close to the limit (# 14), the forward rotation is stopped, and the mask moving path in the cleaning machine between the first roller and the work area is defined as a winding path R2. The path switching mechanism 53 of each of the two

cleaning machines

50A and 50B is controlled so that the mask movement path in the cleaning machine between the second roller and the work area is set as the delivery path R1 (# 15). Whether or not the delivery has reached the limit can be determined by providing a mark (for example, a hole) in the vicinity of the mask edge and detecting it optically or mechanically. After setting the path in the washing machine, reverse rotation of the roller pair is started (# 16). The reverse rotation is a rotation in which the second roller feeds the mask and the first roller winds the mask. The reverse rotation is also intermittent or continuous rotation.

When the delivery by the second roller reaches or reaches a limit (# 17), the reverse rotation is stopped and the process returns to step # 12 to switch the path in the cleaning machine and the rotation direction of the roller pair. .

Using the above masking device 40 has the following advantages. A part of each of the belt-like masks 41 to 44 is used as a substantial shield for masking in one spraying, and different parts of the masks 41 to 44 are moved in the length direction during a plurality of maskings. Since it can be used, the deposition amount of the substance adhering to the mask can be reduced. By reducing the deposition amount, it is possible to prevent the boundary between the masking region and the non-masking region from being distorted by the deposit, and it is possible to shorten the time required for cleaning the mask. On the other hand, in the masking with a fixed mask of the same size as the object to be masked, the amount of deposited substances can be reduced by frequently changing the mask, but the work of replacing the mask is difficult. Is expensive and requires a lot of money to prepare and store a large number of masks.

Since the belt-shaped masks 41 to 44 are rolled in a roll form, unlike the circulation form, the route of the loop is not complicated even if the mask is sufficiently long.

Since the

rollers

45A, 45B, 46A, 46B, 47A, 47B, 48A, and 48B around which the masks 41 to 44 are wound are arranged on both sides of the conveyance path of the substrate 10 that is a masking target, they are arranged above the conveyance path. The configuration of the system 100 can be simplified compared with the case where In the configuration in which the

cleaning machines

50A and 50B are assembled, the degree of freedom of arrangement of the

cleaning machines

50A and 50B is large. The positions in the width direction of the masks 41 to 44 can be made variable by a simple mechanism.

Since the positions in the width direction of the first and

fourth masks

41 and 44 are variable, the masking apparatus 40 can be used for manufacturing a plurality of types of plasma display panels having different screen sizes.

Since the used portions of the masks 41 to 44 are cleaned before the winding is performed and the cleaning liquid is removed, the change over time of the masks 41 to 44 is compared with the case where the mask 41 is wound with the deposit remaining or wet with the cleaning liquid. Can be reduced.

In the above embodiment, the configuration of the system 100 is not limited to the example. The substance sprayed by the injection device 20 is not limited to powder, but may be a liquid in which the powder is dispersed or another solution. The nozzle 21 may be fixedly arranged, or may move along the surface of the object.

The transfer device 30 is not limited to the belt conveyor type, and may be a robot that handles the substrate 10 with an arm, for example.

The number of masks in the masking device 40 is not limited to four. The configuration including only the first mask 41 or the configuration including only two masks that intersect each other (for example, the mask 41 and the mask 44) may be employed. Furthermore, it is possible to arrange three or more strip masks in parallel with the first mask 41, or to arrange three or more strip masks in parallel to the transport direction (M1) of the substrate 10. The distance between the parallel masks in the work area and the width of each mask may be appropriately selected according to the size of the substrate 10. The mask arrangement may be adapted to the masking target. For example, when masking a mother substrate in order to manufacture a plurality of plasma display panels at once, the masks are arranged so that a plurality of separated layers are formed.

In the

washing machines

50A and 50B, the blower 54 on the sending side may be stopped as described above, or the blower 54 may be operated regardless of winding and sending. In the illustrated example, air is blown to the mask after winding and before winding, but in addition to the blower 54, a blower for blowing air to the mask from the

washing machines

50A and 50B toward the work area can be provided.

The cleaning liquid 52 is selected according to the sprayed material, and the mask material is selected in consideration of resistance to the cleaning liquid. The size and material of the roller and pulley are also selected as appropriate. The surface of the roller or pulley may be a smooth surface or a surface that has been processed to increase the frictional force, or may be a surface having elasticity such as synthetic resin or synthetic rubber.

The present invention can be used for masking for forming a film having a desired pattern including a coating film.

Claims

A masking device for performing masking to attach a substance to a surface of an object except for a part thereof,
A strip-shaped mask extending across the work area where the object to be masked is placed;
A pair of forward and reverse rotatable rollers that wind the mask on both sides of the mask in the extending direction of the mask with respect to the work area;
A masking apparatus, wherein the mask is reciprocated by switching the rotation direction of the pair of rollers.
The masking apparatus according to claim 1, wherein a position in the width direction of the mask in the work area is variable.
The masking apparatus according to claim 1, further comprising: a plurality of cleaning machines that are disposed between each of the pair of rollers and the work area and remove substances adhering to the mask from the mask.
Each of the plurality of washing machines
A liquid tank containing the cleaning liquid;
The masking apparatus according to claim 3, further comprising: a mechanism for switching a movement path of the mask in the cleaning machine to either a winding path that passes through the cleaning liquid or a delivery path that does not pass through the cleaning liquid. .
The masking apparatus according to claim 4, wherein each of the plurality of cleaning machines includes means for removing the cleaning liquid adhering to the mask that has passed through the cleaning liquid.
A system used in a process of partially attaching a layer forming material to the surface of a substrate in the manufacture of a plasma display panel,
An injection device for injecting the layer forming material downward from the injection port;
A transport device for transporting the substrate in one direction and arranging it in a work area below the ejection port;
A masking device that partially hides the surface of the substrate disposed in the work area with respect to the ejection port;
The masking device is
A strip-shaped mask extending across the work area along a direction intersecting the transport direction of the substrate;
A pair of forward and reverse rotatable rollers that wind the mask on both sides of the mask in the extending direction of the mask with respect to the work area;
The plasma display panel manufacturing system, wherein the mask is reciprocated by switching the rotation direction of the pair of rollers.
A system used in a process of partially attaching a layer forming material to the surface of a substrate in the manufacture of a plasma display panel,
An injection device for injecting the layer forming material downward from the injection port;
A transport device for transporting the substrate in one direction and arranging it in a work area below the ejection port;
A masking device that partially hides the surface of the substrate disposed in the work area with respect to the ejection port;
The masking device is
First and second strip-shaped masks extending away from each other so as to cross the work area along a direction intersecting the transport direction of the substrate;
Two pairs of forward and reverse rotating rollers for winding the first and second masks on both sides of the working area in the extending direction of the mask,
The plasma display panel manufacturing system, wherein the rotation directions of the two pairs of rollers are switched to reciprocate the first and second masks, respectively.
The plasma display panel manufacturing system according to claim 7, wherein the position in the transport direction in the work area is variable for at least one of the first and second masks.
The masking device is
In the work area, the first and second masks are separated from each other and extend in the transport direction, and are distributed outside the work area to one side and the other side in the extending direction of the first and second masks with respect to the work area. A third and fourth strip-shaped mask;
Two pairs of forward and reverse rotating rollers that wind the third mask on one side of the working area in the extending direction and wind the fourth mask on the other side;
The plasma display panel manufacturing system according to claim 7, wherein the third and fourth masks are reciprocated by switching a rotation direction of a roller that winds the third and fourth masks.
The plasma display panel manufacturing system according to claim 9, wherein a position in the extending direction in the work area is variable for at least one of the third and fourth masks.
The material substances disposed on both sides in the extending direction with respect to the working area and attached to the first, second, third and fourth masks are removed from the first, second, third and fourth masks. The plasma display panel manufacturing system according to claim 9, comprising a plurality of cleaning machines.