JP3682434B2 - Screen printing method and apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention includes printing of resist for edging on a circuit board in IC manufacturing, printing of a wiring diagram on a printed circuit board, pattern printing on a board in manufacturing of a gas discharge panel (PDP) of a plasma display, and various others. More particularly, the present invention relates to a screen printing method and apparatus that facilitates separation of a screen mesh through which a squeegee has passed and a substrate to be printed.
[0002]
[Prior art]
In the screen printing, as shown in FIG. 7, after the ink 8 is supplied to the screen plate 1 made of a screen mesh formed of stainless steel or the like in a fine mesh shape, the squeegee 6 is placed on the ink mesh 8 supply surface side of the screen mesh. By sliding, the ink 8 is pushed out from the opening to be printed on the screen mesh, and the ink 8 is applied to the printing material 10 on the printing table 11 arranged on the side opposite to the sliding surface of the squeegee 6 of the screen plate 1. In general, printing is performed by transferring the color.
[0003]
In the above-mentioned screen printing, printing defects such as ink 8 supplied to the screen mesh adhering to the printing material 10 due to contact between the screen mesh of the screen plate 1 and the printing material 10 other than when the squeegee 6 slides are prevented. From the viewpoint of, for example, a gap of about 2 mm to 6 mm is usually provided in the substrate 10 and the screen plate 1, and the sliding surface of the screen mesh only when the squeegee 6 slides on the screen mesh. And the printing surface of the substrate 10 corresponding to the sliding surface are brought into contact with each other to transfer the ink 8, and after the contact, the screen mesh through which the squeegee 6 has passed by the tension of the screen plate 1 is transferred to the printing surface of the substrate 10. It was configured to separate from.
[0004]
[Problems to be solved by the invention]
However, in the conventional screen printing described above, the screen mesh and the substrate 10 are brought into contact with each other by the squeegee 6 sliding on the screen mesh and stretching the screen mesh. It was difficult to increase durability.
[0005]
Further, after the screen mesh is brought into contact with the substrate 10 with the squeegee 6, the tension to such an extent that the sliding surface of the screen mesh is separated from the printing surface of the substrate 10 is set to the entire printing surface of the substrate of the screen plate 1. In order to hold the entire opening, it is necessary to make the screen plate 1 about twice as large as the printing area, which causes a problem in terms of cost.
[0006]
Furthermore, since printing is performed by extending the screen mesh, it is difficult to accurately transfer the ink 8 to the substrate 10 corresponding to the shape of the aperture 5 formed on the screen mesh, and it is the limit to increase the printing accuracy. was there.
[0007]
In order to increase the printing accuracy, it is conceivable that the gap between the screen mesh and the substrate 10 is made as narrow as possible, and the ink 8 is transferred to the substrate 10 without extending the screen mesh.
[0008]
However, if the gap is narrowed, as described above, the screen mesh and the printing material may come into contact with each other except when the squeegee 6 passes, and printing failure may occur. Compared to the periphery of the screen frame 3 that is the outer periphery in particular. Thus, the possibility of this contact is increased at the center of the screen mesh which is easily bent.
[0009]
In this case, since the screen mesh is printed without being stretched, it becomes difficult to separate the screen mesh and the printing material 10 by the tension of the screen plate 1, and this is because the gap between the screen mesh and the printing material 10 is narrow. As a result, the screen mesh and the substrate 10 are in a state of being bonded via the ink 8 and it becomes difficult to separate them. In the case of performing the separation, the screen mesh may be inclined at the time of separation, which may cause printing defects such as uneven adhesion of the ink 8 to the substrate 10.
[0010]
In order to solve the above problem, the present invention includes a configuration in which the sliding surface of the screen mesh is separated from the printing surface of the substrate 10 after contact between the screen mesh and the substrate, thereby providing a gap between the screen mesh and the substrate. Can be kept narrow compared to the conventional case, the printing accuracy can be improved, the screen mesh can be prevented from being deteriorated by extending the screen mesh, and the tension of the screen plate 1 can be maintained. It is an object of the present invention to provide a screen printing method and apparatus that does not require a screen mesh to be secured more than necessary.
[0011]
[Means for Solving the Problems]
In the screen printing method of the present invention, as described above, an ink supply unit supplies ink to a screen plate that is composed of a screen mesh and a screen frame that holds the screen mesh and is arranged at a predetermined interval with respect to a printing object. A squeegee is slid on the screen mesh supplied with the ink, and the screen mesh is brought into contact with the substrate to be printed on the back surface of the sliding position of the squeegee, and from the opening formed in the screen mesh. In a screen printing step of extruding ink and transferring the ink to a printing surface corresponding to the sliding surface of the substrate, While supplying the ink to the screen mesh through which the squeegee has passed by moving the ink supply unit arranged close to the squeegee in synchronization with the squeegee, When the squeegee slides, at least the screen plate and the printing material are in a pressure state in which the screen mesh through which the squeegee has passed is separated from the printing surface of the printing material (Claim 1).
[0012]
The pressure state can be achieved by introducing a gas between the screen plate and the substrate. (Claim 2). This gas can be achieved by introducing the gas along the sliding direction of the squeegee (Claim 3) or by setting the squeegee sliding surface side of the screen plate to a negative pressure. (Claims 4 ).
[0014]
Further, between the screen plate and the substrate. Preferably A gap of 1 mm or more is formed, and then the pressure state is generated between the screen plate and the substrate, and the gap between the screen plate and the substrate is maintained while maintaining the pressure state. Preferably The printing is sequentially performed by fully opening the screen plate on the substrate to be less than 1 mm, and the gap between the screen plate and the substrate is again formed. Preferably The pressure state can also be released as 1 mm or more. 5 ).
[0015]
And this invention screen printing apparatus,
A screen plate composed of a screen mesh and a screen frame holding the screen mesh and arranged at a predetermined interval with respect to the printed material; an ink supply unit for supplying ink to the screen plate; and sliding on the screen mesh; The screen mesh is brought into contact with the substrate at the back surface of the sliding contact position, and the ink is transferred to the printing surface corresponding to the sliding surface, and a squeegee for extruding ink from an opening formed in the screen mesh. A printing stand for supporting the substrate to be printed, While supplying the ink to the screen mesh through which the squeegee has passed by moving the ink supply unit arranged close to the squeegee in synchronization with the squeegee, When the squeegee slides, there is provided pressure adjusting means for bringing the screen mesh through which the squeegee has passed away from the printing surface of the printing material at least between the screen plate and the printing material. Claim 6 ).
[0016]
The pressure adjusting means has a mechanism for supplying a gas into a differential pressure chamber formed by sealing between the screen plate and the printing material, preferably between the screen plate and the printing material. Is preferable. 7 ). It is preferable that the pressure adjusting means can supply gas in the same direction as the squeegee in the traveling direction between the screen plate and the substrate. 8 ). Further, gas can be supplied by a nozzle that opens between the screen plate and the substrate (claim). 9 ).
[0017]
Alternatively, the pressure adjusting means may have a mechanism for sucking air on the squeegee sliding surface side of the screen plate. 10 ).
[0019]
Further, it is preferable that two squeegees are arranged between the two ink supply units, and the two ink supply units and the two squeegees are provided so as to be reciprocally movable on a screen plate. 11 ).
[0020]
It is preferable to provide a gap adjusting means that adjusts the substrate to be printed and the screen plate so as to be able to approach and separate, for example, a mechanism that moves at least a part of the screen plate and / or the printing table. Term 12, 13 ). It is also possible to arrange one squeegee between a pair of ink supply units, and provide the two ink supply units and the squeegee so as to reciprocate on the screen plate so that reciprocal printing is possible ( Claim 14 ).
[0021]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the screen printing process of the present invention will be described together with the apparatus.
[0022]
The screen printing apparatus of the present invention comprises a screen mesh and a screen frame 3 that holds the screen mesh. Placed on the printed material at a predetermined interval Sliding on the screen plate 1, the ink supply unit 9 for supplying the ink 8 to the screen plate 1, and the screen mesh; The screen mesh is brought into contact with the substrate on the back surface of the sliding contact position, and the holes formed in the screen mesh A squeegee 6 for extruding the ink 8 from the printing surface 11 and a printing table 11 for supporting the substrate 10 on which the ink 8 is transferred to the printing surface corresponding to the sliding surface; When sliding the squeegee, At least between the screen plate 1 and the substrate 10, there is provided pressure adjusting means 20 for bringing the screen mesh through which the squeegee 6 has passed separates from the printing surface of the substrate 10. As an example, FIG. As shown in FIG.
[0023]
In FIG. 1, reference numeral 1 denotes a screen plate, which is a plate surrounded by a screen frame 3 in which a screen mesh having openings 5 for forming printing openings or pattern holes which are printing portions excluding the shielding portion 4 is surrounded by a screen frame 3. It is also possible to use a thin metal plate such as stainless steel in which the image line portion 5 is formed as an opening by drilling.
[0024]
As a general screen mesh, various known screen meshes can be used. For example, stainless steel, polyamide (nylon; DuPont), tetron, and silk having a mesh structure can be used. It is not limited to this as long as it can be organized and used as a screen mesh. The shielding part 4 uses, for example, a PVA (polyvinyl alcohol) generally used for the amount of plate making materials such as gelatin and emulsion (emulsion) and a vinyl acetate emulsion containing a diazo type photosensitive agent as a photosensitive emulsion. Can do.
[0025]
Reference numeral 6 denotes a squeegee, which slides on the screen mesh of the screen plate 1 to allow the ink 8 supplied to the screen mesh from the ink supply unit 9 to pass through the openings 5 formed in the screen mesh to the printed material 10 side. It extrudes toward
[0026]
The ink 8 can be widely used as long as it can be applied to screen printing, such as water-based, oil-based, synthetic resin-based, emulsion-based, or a paste formed by mixing metal powder such as silver. Can do.
[0027]
Examples of the substrate 10 to which the ink 8 is transferred by sliding the squeegee 6 include an IC circuit board, a printed board, a plasma display panel board, and the like, which can be printed by the screen printing means of the present invention. If so, various materials such as paper, cloth, resin, metal, ceramics (including glass and the like) can be used as the printing material.
[0028]
The substrate 10 is supported by a printing table 11 that is in contact with the lower surface of the substrate 10. The printing stand 11 has a configuration for fixing and supporting the printing substrate 10 in order to prevent the printing substrate 10 from being displaced during printing or adhering to the screen plate 1 and floating. In the embodiment, a vacuum pump (not shown) is provided at a lower part of the printing substrate 11 fixing portion of the printing stand 11, and the printing substrate 10 is adsorbed and fixed by the vacuum pump.
[0029]
The substrate 10 is disposed on the opposite side of the screen plate 1 from the sliding surface of the squeegee 6 with a predetermined gap in parallel with the screen plate 1.
[0030]
The gap between the screen plate 1 and the substrate 10 is preferably 2 mm or less and 0.01 mm or more.
[0031]
Reference numeral 20 denotes pressure adjusting means. In this embodiment, the blower 21 is used as the pressure adjusting means 20, and gas is supplied between the screen plate 1 and the substrate 10 by the blower 21.
[0032]
Due to the supply of gas by the blower 21, the pressure between the screen plate 1 and the substrate 10 is higher than the sliding surface of the squeegee 6 of the screen plate, and a differential pressure is generated with the screen plate 1 as a boundary. Due to this differential pressure, a force is exerted on the screen mesh to leave the substrate 10. Therefore, even if the gap between the screen plate 1 and the substrate 10 is narrowed, they can be prevented from contacting each other. Even if the screen mesh and the substrate 10 are in contact with each other due to the sliding of the squeegee 6 during printing, Both can be easily separated by moving the squeegee.
[0033]
Since the size of the differential pressure required to separate the screen mesh and the printing material 10 that are in contact with each other by sliding the squeegee 6 depends on the viscosity of the ink 8 used for printing, the size of the printing pattern, etc. The pressure adjusting means 20 preferably includes a mechanism capable of adjusting the pressure state between the screen plate 1 and the substrate 10 in accordance with these conditions.
[0034]
In the present embodiment, the blower 21 is provided with an inverter circuit that controls the rotation speed of the electric motor as a drive source as a rotation control means, and the screen plate is converted by converting the AC frequency by the inverter circuit. The flow rate of the gas supplied between 1 and the substrate 10 is changed, and the pressure state between the screen plate 1 and the substrate 10 is adjusted. If the rotational speed of the motor of the blower 21 is increased by the inverter circuit, the amount of gas supplied between the screen plate 1 and the substrate 10 increases and the pressure increases, so that the screen mesh becomes the substrate 10. The power to leave is increased. When a motor such as an oriental motor is used, it is possible to control the rotational speed as described above by using a variable resistor instead of the inverter.
[0035]
As the gas supplied between the screen plate 1 and the substrate 10 by the blower 21 which is the pressure adjusting means 20, an inert gas such as nitrogen gas or argon can be used, but in this embodiment, Air is supplied.
[0036]
The gas can be supplied to the inside of the differential pressure chamber 30 by defining the space between the screen plate 1 and the substrate 10 in a substantially sealed or compacted state to form the differential pressure chamber 30. . This makes it possible to form the pressure state with a small amount of gas as compared to when the portion is open.
[0037]
In the present embodiment, the pressure retaining frame 12 whose outer periphery substantially coincides with the screen frame 3 of the screen plate 1 is arranged between the screen plate 1 and the printing stand 11 for fixing the printing material 10, and the screen plate 1 and the printing are printed. The differential pressure chamber 30 is formed by sealing between the bases 11. Further, a nozzle 17 of a supply pipe 15 communicating from the blower 21 into the differential pressure chamber 30 is provided through the printing table 11, and the gas supplied by the blower 21 passes through the supply pipe 15 to the differential pressure chamber. 30 is configured to be supplied in the interior. The nozzle 17 of the supply pipe 15 only needs to be able to supply gas into the differential pressure chamber 30, and may be provided, for example, in the screen frame 3 of the screen plate 1.
[0038]
Further, the gas is preferably supplied in the same direction as the moving direction of the squeegee 6 that slides on the screen plate 1 so that the screen mesh through which the squeegee 6 passes can be easily separated from the substrate 10. A nozzle 17 that is connected to the blower 21 and injects the gas is provided in the lower part of the screen plate 1, and the gas flows from the nozzle 17 in the same direction as the movement direction of the squeegee 6 on the screen mesh. Can be supplied.
[0039]
In the present embodiment, the pressure adjusting means 20 used for gas supply is, for example, the blower 21 of SF-50 manufactured by Showa Denki Co., Ltd., but a fan or a compressor is also used. Various types such as a turbo type such as an axial flow type and a centrifugal type, and a positive displacement type such as a rotary type and a reciprocating type can be used. By supplying gas, at least the screen plate 1 can be used. Any configuration may be employed as long as the screen mesh through which the squeegee 6 passes can be separated from the printing surface of the printing material 10 between the printing material 10 and the printing material 10.
[0040]
In the embodiment shown in FIG. 1, the differential pressure chamber 30 is formed. However, without forming this differential pressure chamber, as shown in FIG. A pressure holding frame 12 is provided to form a differential pressure chamber 30 so that the outer periphery of the screen plate 1 substantially coincides with the screen frame 3 so that the screen plate and the printing stand 11 can be sealed except for the opening of the screen mesh 2. Then, a gas having a pressure higher than the atmospheric pressure may be supplied through the nozzle 17 from the supply pipe 15 inserted through the hole passing through the pressure holding frame 12. Further, as shown in FIG. 6, a high pressure is applied to the gap between the screen mesh 2 and the substrate 10 in the traveling direction of the squeegee 6 or along the screen plate in the traveling direction of the squeegee 6. The nozzle 17 is installed so that gas flows. In the embodiment shown in FIGS. 5 and 6, other configurations are the same as those shown in FIG. 7, and the description thereof is omitted. In these embodiments, the distance between the substrate 10 and the screen mesh 2 is preferably set to 2 mm or less and 0.01 mm or more.
[0041]
As still another embodiment of the present invention, as shown in FIG. 2, a vacuum pump 22 or a suction blower is used as the pressure adjusting means 20, and the squeegee 6 of the screen plate 1 is slid by the vacuum pump 22 or the suction blower. The screen mesh through which the squeegee 6 has passed is at least between the screen plate 1 and the substrate 10 by sucking air on the moving surface side to create a negative pressure on the sliding surface side of the squeegee 6 of the screen plate 1. Can form the pressure state that separates from the printing surface of the substrate 10.
[0042]
As a result of the suction of air by the vacuum pump 22 or the suction blower, the sliding surface side of the squeegee 6 of the screen plate becomes negative pressure, so that the squeegee 6 of the screen plate slides between the screen plate 1 and the substrate 10. Since the pressure is higher than that on the surface side, as in the case of the gas supply by the blower 21 described above, a differential pressure is generated with the screen plate 1 as a boundary, and a force to leave the printing material 10 acts on the screen mesh.
[0043]
Note that the vacuum pump 22 as the pressure adjusting means 20 controls the rotation speed of the electric motor as a drive source so that the pressure state between the screen plate 1 and the substrate 10 can be adjusted according to the printing conditions, similarly to the blower 21. It is preferable to include rotation control means such as an inverter circuit.
[0044]
In the air suction, a differential pressure chamber 40 is formed on the sliding surface side of the squeegee 6 of the screen plate 1 in the same manner as the space between the screen plate 1 and the substrate 10 described above. Can be done against.
[0045]
In the embodiment shown in FIG. 2, the pressure holding case 13 that covers the entire screen mesh is installed on the sliding surface side of the squeegee 6 of the screen plate 1 to form the differential pressure chamber 40, and the vacuum A suction port 18 of a suction pipe 16 communicating from the pump 22 into the differential pressure chamber 40 is provided in the pressure holding case 13, and air in the differential pressure chamber 40 is sucked by the vacuum pump 22.
[0046]
The suction port 18 of the suction pipe 16 may be provided in the screen frame 3 fixed to the pressure holding case 13 as long as it can suck the air in the differential pressure chamber 40.
[0047]
Further, the pressure adjusting means 20 used for air suction is the vacuum pump 22, but the screen mesh through which the squeegee 6 has passed is at least between the screen plate 1 and the substrate 10 from the printing surface of the substrate 10. Any configuration may be used as long as the pressure state can be separated.
[0048]
In the embodiment, when the gas is supplied between the screen plate 1 and the substrate 10 by the blower 21, the sliding surface of the squeegee 6 of the screen plate 1 by the vacuum pump 22 or the suction blower. Although the case where the air on the side is sucked is described as an individual form, the screen plate is used by using both the blower 21 and the vacuum pump 22 in relation to the configuration of the differential pressure chamber or the presence / absence thereof and the adjustment of the pressure difference. It is also possible to simultaneously supply the gas between 1 and the substrate 10 and suck the air on the sliding surface side of the squeegee 6 of the screen plate 1. When the differential pressure chamber 40 is not formed, the suction port 18 is preferably formed to have the same width as the squeegee 6 and moved in synchronization.
[0049]
When printing is performed by the screen printing apparatus, when the squeegee 6 slides and the screen mesh and the substrate 10 come into contact, the ink 8 that has blocked the openings 5 of the screen mesh is transferred to the substrate 10. Therefore, the openings 5 of the screen mesh are opened as the transfer of the ink 8 to the substrate 10 proceeds. As described above, when the openings 5 of the screen mesh are opened, the screen mesh 1 is generated between the screen plate 1 and the substrate 10 and the sliding surface side of the squeegee 6 of the screen plate 1 through the opening. The differential pressure will be relaxed.
[0050]
At this time, in order to maintain the pressure state in which the screen mesh through which the squeegee 6 has passed is separated from the printing surface of the printing material 10 between the screen plate 1 and the printing material 10, the pressure adjusting means is the blower 21. In this case, it is necessary to increase the output of the pressure adjusting means, for example, by increasing the gas supply amount by this, and by using the vacuum pump 22 or the suction blower by increasing the air suction amount by this. This problem is particularly remarkable in a printing pattern in which the area of the opening 5 is large.
[0051]
In addition, although not shown in the drawings, in the above-described embodiment, it is possible to employ means such as manually supplying ink as in the conventional case using a conventional squeegee 6.
[0052]
Therefore, it is preferable that the ink supply unit 9 for supplying the ink 8 to the screen mesh of the screen plate 1 is provided in the vicinity of the squeegee 6 as shown in FIGS. .
[0053]
In the embodiment shown in FIGS. 1 and 2, when the squeegee 6 slides on the screen mesh, the ink supply unit 9 moves close to the rear of the squeegee 6 and When the ink 8 is supplied onto the screen mesh on which the squeegee 6 has slid, and the sliding of the full aperture 5 of the screen plate 1 is completed, the squeegee 6 returns to the predetermined sliding start position. It is comprised so that it may move in the state where it adjoined ahead of No.6.
[0054]
When the ink supply unit 9 moves in synchronism with the squeegee 6 in proximity to the squeegee 6, when the squeegee 6 slides on the screen mesh and performs printing, the ink is transferred to the printing material and the opening is opened. Since the hole 5 is closed with the ink 8 supplied by the ink supply unit 9, the pressure difference due to the opening is prevented from being reduced, and the output of the pressure adjusting means 20 such as the blower 21 and the vacuum pump 22 is not increased. The pressure state between the screen plate 1 and the substrate 10 can be maintained.
[0055]
The distance between the squeegee 6 and the ink supply unit 9 is a range in which the ink 8 supplied by the ink supply unit 9 does not adhere again to the printing surface of the substrate 10 on which printing has been performed by sliding the squeegee 6. Preferably, the distance between the squeegee 6 and the ink supply unit 9 is such that the ink 8 supplied by the ink supply unit 9 is applied to the printing surface of the substrate 10 on which printing has been performed by sliding the squeegee 6. It is preferable to make it the range which does not adhere again, and 150 mm or less and 20 mm or more are suitable.
[0056]
In the screen printing method of the present invention, the gap between the screen plate 1 and the substrate 10 can be set narrow, and the deformation of the screen plate 1 can be reduced to prevent the printing position from being shifted. The ink supply unit 9 can be configured such that two of these are provided and reciprocal printing is possible.
[0057]
For example, as shown in FIG. 3, the forward squeegee 6 and the ink supply unit 9 function when moving from the right side to the left side of FIG. 3, and the return path functioning when moving from the left side to the right side of FIG. The squeegee 6 'and the ink supply unit 9' are provided so as to face each other, and they can be configured to reciprocate on the screen mesh.
[0058]
Hereinafter, the printing operation in this case will be described with reference to FIG.
[0059]
First, the ink 8 is supplied to the full aperture 5 on the screen mesh by the ink supply unit 9 for the forward path. At that time, the forward squeegee 6, the backward squeegee 6 ′, and the ink supply unit 9 ′ also move from the right side to the left side of the drawing together with the ink supply unit 9 (FIG. 3-1).
[0060]
Next, the return path squeegee 6 'moves on the screen mesh supplied with the ink 8 while sliding from the left side to the right side of the drawing, and the return path ink supply section 9' slides on the squeegee 6 '. Accordingly, the ink 8 is supplied to the opening 5. At this time, the forward squeegee 6 and the ink supply unit 9 move together with the return squeegee 6 ′ and the ink supply unit 9 ′ (FIG. 3-2).
[0061]
After sliding (printing) of the full opening 5 is completed by the return squeegee 6 ', the forward squeegee 6 is supplied with ink to the full opening 5 by the return path ink supply section 9'. Further, it moves on the screen plate 1 while sliding from the right side to the left side of the drawing. At this time, the ink supply section 9 for the forward path supplies the ink 8 to the opening 5 opened by the sliding of the squeegee 6, and the squeegee 6 'and the ink supply section 9' for the backward path do not function. It moves together with the forward squeegee 6 and the ink supply unit 9 (FIG. 3-3).
[0062]
Thereafter, continuous reciprocating printing is performed by repeating the operations shown in FIGS. 3-2 and 3-3.
[0063]
In addition, replacement | exchange of the to-be-printed material 10 is performed when the sliding of all the apertures 5 is complete | finished by the squeegees 6 and 6 '.
[0064]
According to the screen printing process and apparatus of the present invention, the pressure state in which the screen mesh through which the squeegee 6 has passed is separated from the printing surface of the printing material 10 between the screen plate 1 and the printing material 10 by the pressure adjusting means. By doing so, it is possible to print with the gap between the screen mesh and the printed material narrowed. However, when the printed material 10 is fixed to the printing stand 11 before the start of printing, or after the printing is finished, the printed material 10. When the pressure state between the screen plate 1 and the substrate 10 is released when the paper is taken out, the screen mesh may be bent by its own weight or the weight of the ink 8, thereby causing a printing defect due to contact with the substrate 10. There is.
[0065]
In particular, when the printing area is large and the screen plate 1 is large, such as the formation of a substrate for a plasma display, the central portion of the screen mesh is more easily bent than the outer periphery held by the screen frame 3, and this phenomenon is remarkable. .
[0066]
Therefore, it is preferable to provide a gap adjusting means that can change between the substrate 10 and the screen plate 1 when the pressure state is formed and when the pressure state is released.
[0067]
The adjustment of the gap is performed, for example, by appropriately moving the printing table 11 that fixes the substrate 10 to the driving device so as to move up and down to approach and separate from the screen plate 1, or similarly, the screen plate 1 is moved to the printing table 11. It can be performed by approaching and moving away from each other or by moving both of them. In the screen printing apparatus of the present embodiment, as shown in FIG. 4, for example, a ball screw is used to move the printing table or screen plate up and down, and the amount of rotation is changed by rotating the motor. Alternatively, the gap is adjusted by moving the screen plate up and down to adjust the gap so that only the portion corresponding to the portion where the substrate 10 is fixed is moved toward and away from the screen plate 1 with respect to a part of the printing table 11. However, the configuration is not limited to this as long as the printed material 10 and the screen plate 1 can be uniformly moved away from each other while maintaining the parallel state.
[0068]
Hereinafter, the printing procedure will be described with reference to FIG.
[0069]
First, before the start of printing, the gap between the screen plate 1 and the substrate 10 is set to be wider than that at the time of printing, for example, 15 to 35 mm, preferably 1 mm or more so that the screen mesh and the substrate 10 do not come into contact with each other. (Figure 4-1).
[0070]
Next, the pressure adjusting means 20 forms the pressure state between the screen plate 1 and the substrate 10, and the gap adjusting unit preferably sets the gap between the screen plate 1 and the substrate 10 while maintaining the pressure state. The squeegee 6 slides on the screen mesh to which the ink 8 is supplied, and printing is performed (FIG. 4-2).
[0071]
When printing of all the apertures by the squeegee 6 is completed, the distance between the screen plate 1 and the substrate 10 is again increased to preferably 1 mm or more, for example, 15 to 35 mm by the gap adjusting means. Thereafter, the pressure state by the pressure adjusting means 20 is released, and the substrate 10 is replaced (FIG. 4-3).
[0072]
In the embodiment shown in FIG. 3, the operations of the squeegee 6 and the ink supply unit 9 are the same as those in the prior art. However, as shown in FIGS. The ink supply unit 9 may supply the ink 8 from the rear of the squeegee 6 following the sliding of the squeegee 6, and includes two pairs of the squeegee 6 and the ink supply unit 9 as shown in FIG. You may comprise so that reciprocal printing is possible. By replacing the squeegee 6 and the ink supply unit 9 with the above configuration, the pressure state between the screen plate 1 and the substrate 10 can be more suitably maintained. In the configuration of FIG. 1, the operation of the ink supply unit 9 can be alternately performed as described above, and the ink supply unit 9 can be provided on both sides of the squeegee 6 for reciprocal printing.
[0073]
In the following embodiments, examples of using the screen printing method and apparatus of the present invention for manufacturing plasma displays and ICs, etc. are described. It is not limited to those intended for printing, and can be used in the general printing field to which known screen printing can be applied as described above.
[0074]
Example 1
Silver paste was used on the 20-inch plasma display back plate to form address electrodes.
[0075]
The gap between the screen plate and the glass substrate as the substrate to be printed is set at 0.5 mm, a pressure holding frame is provided in the gap between the screen frame and the printing stand for adsorbing the substrate, and 0.1 MPa from the supply pipe 15 below the screen frame. Introduced air of pressure.
[0076]
The size of the screen plate was set approximately 80 mm larger than the print pattern size. Printing was performed with a stainless 320 mesh using a silver pace manufactured by NAMICS.
[0077]
Conventionally, printing was performed with a gap of 3 to 5 mm. However, even with a gap of 0.5 mm, it was possible to print without separating the glass substrate and the screen plate.
[0078]
Example 2
A wiring pattern was formed on a 200 mm × 200 mm alumina substrate having a thickness of 0.65 mm using a silver paste.
[0079]
The alumina substrate is adsorbed to the printing stand with a vacuum pump, the gap between the screen plate and the alumina substrate is set to 0.2 mm, and a pressure holding frame is provided in the gap between the screen frame and the printing stand to adsorb the substrate. Further, gas was introduced by a blower into the gap between the screen plate and the printing stand for adsorbing the substrate from the supply pipe by a blower with the inverter frequency set to 18 Hz.
[0080]
Using a urethane squeegee with a rubber hardness of 80 degrees, a silver pace made by Namics Co., Ltd. was printed on a glass substrate with a screen printing plate made of stainless steel 320 mesh.
[0081]
In this example, printing was conventionally performed with a gap of 3 to 5 mm. However, even with a gap of 0.2 mm, it was possible to print without separating the glass substrate and the screen plate.
[0082]
Example 3
The dielectric printing of the back plate of the plasma display was performed on a 200 mm × 300 mm glass substrate.
[0083]
As shown in FIG. 4, two squeegees and two ink application portions are attached to a 350 mm × 500 mm screen plate, and printing is performed using 320-mesh stainless screen mesh using Asahi Glass dielectric ink.
[0084]
As shown in FIG. 4, a screen printing machine having a mechanism in which the printing stand is lowered at times other than printing is used.
[0085]
A glass substrate is installed on the processing board suction part of the printing table, and the screen printing table is moved below the screen plate, so that the gap between the screen plate and the processing substrate is 3 mm as shown in (4-1) of FIG. Set.
[0086]
The screen plate and the screen printing stand were hermetically sealed with a pressure holding frame, and the blower air with the blower inverter set to 18 Hz was introduced between the screen plate and the screen printing stand so that the pressure was higher than the atmosphere.
[0087]
As shown in FIG. 3 (3-1), the ink application part at the right end was lowered and moved from right to left to apply ink to the screen plate.
[0088]
As shown in (4-2) of FIG. 4, the gap between the screen plate and the processed substrate is set to 0.2 mm, and as shown in (3-2) of FIG. The squeegee was lowered, moved from left to right, and ink was applied to the screen plate while printing with the squeegee.
[0089]
As shown in (4-3) of FIG. 4, after setting the gap between the screen plate and the processed substrate to 3 mm, the blower air is stopped to release the pressure holding frame, and the printing stand is moved from under the screen plate. The printed processed substrate is taken out, another new processed substrate is set on the processed substrate suction portion of the screen printing table, and the screen printing table is moved under the screen plate, as shown in FIG. As described above, the gap between the screen plate and the processed substrate was set to 3 mm.
[0090]
The screen plate and the screen printing stand were hermetically sealed with a pressure holding frame, and the blower air with the blower inverter set to 18 Hz was introduced between the screen plate and the screen printing stand so that the pressure was higher than the atmosphere.
[0091]
As shown in (4-2) of FIG. 4, the gap between the screen plate and the processed substrate is set to 0.2 mm, and as shown in (3-3) of FIG. The squeegee was lowered, moved from right to left, and ink was applied to the screen plate while printing with the squeegee.
[0092]
By repeating this, the dielectric is continuously printed on the processed substrate, and even if the squeegee is moved twice as fast as the conventional method, the screen plate and the processed substrate can be printed without sticking. The service life can be extended to about three times the conventional one.
[0093]
Even if the dielectric is printed on the processed substrate continuously and the squeegee is moved twice as fast as the conventional one, the screen plate and the processed substrate can be printed without sticking. I was able to extend it 3 times.
[0094]
【The invention's effect】
As described above, according to the screen printing method and apparatus of the present invention, at least the screen plate 1 and the substrate 10 are in a pressure state in which the screen mesh through which the squeegee 6 has passed is separated from the printing surface of the substrate 10. The following effects can be obtained.
[0095]
Since it is possible to separate the screen mesh and the printed material without using the tension of the screen plate, it is possible to prevent printing defects due to the contact between the two, and the gap between the screen plate and the printed material is made larger than before. Can be narrowed.
[0096]
Accordingly, it is possible to prevent a decrease in printing accuracy and deterioration of the screen mesh due to the use of the screen mesh being stretched, and it is not necessary to secure the screen mesh wider than the print pattern.
[0097]
In addition, by moving the ink supply unit close to the squeegee in synchronization therewith, when the squeegee slides on the screen mesh for printing, the ink is transferred to the substrate to be printed and the opening is opened. The ink 8 can be immediately closed, and the pressure state can be easily maintained.
[0098]
In addition, by making the gap between the screen plate and the substrate to be printed narrower than before, reciprocal printing can be performed, and by providing the reciprocating printing configuration, printing efficiency can be dramatically improved.
[0099]
Further, by making it possible to adjust the distance between the screen plate and the substrate, the screen mesh and the substrate can be removed even when the pressure state formed between the screen plate and the substrate is released when the substrate 10 is replaced. Printing failure due to contact with the printed material 10 could be prevented.
[Brief description of the drawings]
FIG. 1 is a schematic diagram showing a screen printing apparatus according to an embodiment of the present invention.
FIG. 2 is a schematic diagram showing a screen printing apparatus according to another embodiment of the present invention.
FIG. 3 is a schematic diagram showing a screen printing process and apparatus configured to be capable of reciprocal printing according to another embodiment of the present invention.
FIG. 4 is a schematic view showing a screen printing process and apparatus having a gap adjusting means for adjusting a gap between a screen plate and a substrate, which is another embodiment of the present invention.
FIG. 5 is a schematic view showing another embodiment of the present invention.
FIG. 6 is a schematic view showing still another embodiment of the present invention.
FIG. 7 is a schematic view showing a conventional screen printing apparatus.
[Explanation of symbols]
1 screen version
2 screen mesh
3 Screen frame
5 Opening
6,6 'squeegee
8 Ink
9,9 'ink supply unit
10 Substrate
11 Printing stand
12 Pressure holding frame
13 Pressure holding case
15 Supply pipe
16 Suction tube
17 nozzles
18 Suction port
21 Blower (pressure adjusting means)
22 Vacuum pump (pressure adjusting means)
30 Differential pressure chamber (between screen plate and substrate)
40 Differential pressure chamber (screen plate squeegee sliding surface side)

Claims (14)

Ink is supplied by an ink supply unit to a screen plate comprising a screen mesh and a screen frame holding the screen mesh and arranged at a predetermined interval with respect to the printed material, and the squeegee is placed on the screen mesh supplied with the ink. The screen mesh is brought into contact with the printed material on the back surface of the squeegee sliding contact position, and ink is pushed out from the openings formed in the screen mesh to correspond to the sliding surface of the printed material. A screen printing method for transferring the ink to a printing surface to be printed,
The ink supply unit arranged close to the squeegee is moved in synchronization with the squeegee to supply ink to the screen mesh through which the squeegee has passed , and at least when the squeegee slides, at least the screen plate and the squeegee A screen printing method, characterized in that a pressure state in which a screen mesh through which the squeegee has passed is separated from the printing surface of the printing material between the printing materials.   2. The screen printing method according to claim 1, wherein a gas is introduced between the screen plate and the printing material to bring the pressure state between the screen plate and the printing material.   The screen printing method according to claim 2, wherein the gas is introduced along a sliding direction of the squeegee.   The screen printing method according to any one of claims 1 to 3, wherein the pressure state is set between the screen plate and the substrate by making the squeegee sliding surface side of the screen plate a negative pressure. . A gap of 1 mm or more is formed between the screen plate and the substrate, and then the pressure state is generated between the screen plate and the substrate, and the screen plate and the substrate are maintained while maintaining the pressure state. wherein the gap between the printed matter as less than 1mm performs printing by the screen plate fully open holes in the substrate, again as above 1mm gap between the printing object and the screen plate according to claim 1-4 to release the pressure condition The screen printing method according to claim 1. A screen plate composed of a screen mesh and a screen frame holding the screen mesh and arranged at a predetermined interval with respect to the printed material; an ink supply unit for supplying ink to the screen plate; and sliding on the screen mesh; The screen mesh is brought into contact with the substrate at the back surface of the sliding contact position, and the ink is transferred to the printing surface corresponding to the sliding surface, and a squeegee for extruding ink from an opening formed in the screen mesh. A printing stand for supporting the substrate to be printed,
The ink supply unit arranged close to the squeegee is moved in synchronization with the squeegee to supply ink to the screen mesh through which the squeegee has passed , and at least when the squeegee slides, at least the screen plate and the squeegee A screen printing apparatus, comprising pressure adjusting means for bringing a screen mesh through which the squeegee has passed between the prints into a pressure state where the screen mesh is separated from the printing surface of the prints. The screen printing apparatus according to claim 6 , wherein the pressure adjusting unit has a mechanism for supplying gas into a differential pressure chamber formed by sealing between the screen plate and the substrate. The screen printing apparatus according to claim 7 , wherein the pressure adjusting unit is capable of supplying gas between the screen plate and the substrate to be printed in the same direction as the squeegee travels. The screen printing apparatus according to claim 7 , wherein the pressure adjusting means includes a nozzle opened toward the space between the screen plate and the substrate. The screen printing apparatus according to claim 6 , wherein the pressure adjusting unit includes a mechanism for sucking air on a squeegee sliding surface side of the screen plate. Placing the squeegee paired between the ink supply portion paired, these second freely reciprocate claim 6-10, wherein any one provided with the ink supply part and said squeegee on the screen plate Screen printing device. The screen printing apparatus according to claim 6 , further comprising a gap adjusting unit that adjusts the printed material and the screen plate so as to be close to and away from each other. The screen printing apparatus according to claim 12 , wherein the gap adjusting means is provided such that at least a part of the screen plate and / or the printing table is reciprocally movable. 11. The screen printing according to claim 6 , wherein one squeegee is disposed between a pair of ink supply portions, and the two ink supply portions and the squeegee are provided so as to reciprocate on the screen plate. apparatus.

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