JP3949315B2 - Viscous material coating apparatus and viscous material coating method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
  The present invention relates to a viscous material application apparatus for applying a viscous material such as an adhesive, cream solder, or conductive paste onto an object to be applied such as a circuit board.And viscous material application methodIt is about.
[0002]
[Prior art]
A basic configuration of a conventional viscous material coating apparatus will be described with reference to a schematic diagram of FIG. As shown in FIG. 29 (a), this viscous material application apparatus adjusts compressed air to the viscous material supply unit 1 that accommodates a viscous material 5 such as an adhesive or cream solder, and the viscous material supply unit 1. The viscous material 5 is discharged from the discharge port 4a of the discharge unit 4 by being pressurized by the compressed air.
[0003]
Further, as shown in FIG. 29B, a valve 16 for starting / ending the supply of compressed air may be arranged between the material supply unit 1 and the discharge unit 4. In this apparatus, when it is desired to discharge the viscous material 5 at a predetermined discharge amount, the viscous material 5 is pressurized and extruded from above by the compressed air supplied from the pressure supply unit 22, the valve 16 is opened, and the viscosity is discharged from the discharge port 4a. Material 5 is discharged. And when application | coating to a circuit board is completed, the valve | bulb 16 is comprised so that it may close.
[0004]
[Problems to be solved by the invention]
However, in the viscous material coating apparatus having the above-described configuration, the compressed air supplied from the pressure supply unit 22 is received above the viscous material 5 accommodated in the viscous material supply unit 1. Due to the viscosity resistance, it is difficult for the pressure to reach the vicinity of the discharge port 4a of the discharge unit 4 at a distance. Therefore, the pressure transmission varies, and it is difficult to obtain a highly accurate discharge amount and discharge pressure.
[0005]
In addition, as shown in FIG. 30, the response time from when a discharge start signal is output at a predetermined pressure to when the discharge is actually started is delayed due to the same cause. There is a waiting time before starting. Further, since the residual pressure remains after the pressurization is completed, the viscous material 5 that hangs down from the discharge port 4a protrudes to the vicinity of the discharge port 4a and adheres to the circuit board when the viscous material application device is next placed on the circuit board. As a result, problems such as the occurrence of bridges occur.
[0006]
Further, in the above conventional apparatus, when the viscous material is collectively supplied in a two-dimensional manner, a so-called multiple nozzle 4c having a plurality of discharge ports 4d as shown in FIGS. 31 (a) and 31 (b) is used. In the case, there were the following problems. In the high-viscosity material, the pressure transmission to the viscous material 5 is not performed uniformly, and when the printing paste 31 is applied on the circuit board 32, the transmission pressure of the compressed air varies depending on the position of the discharge port 4c to be applied. As shown in 32 (a) and 32 (b), there was variation in the discharge amount depending on the discharge position.
[0007]
  Accordingly, the present invention solves the above-described problems, and makes it possible to improve the discharge accuracy and increase the efficiency by efficiently performing the pressure transmission for discharging the viscous material to improve the responsiveness.And viscous material application methodTo provideWith the goal.
[0008]
[Means for Solving the Problems]
  In order to achieve the above object, the present invention provides a discharge port.HavePressurization chamberWhen,The pressure chamberA viscous material is supplied between the air bag provided in the air bag, and the inner wall of the pressurizing chamber and the air bag.Viscous material supply meansSupplied,Pressurized chamberThe viscosity ofPressure adjusting means for adjusting the discharge pressure of functional materialAnd air adjusting means for adjusting the amount of air in the air bag based on the pressure of the viscous material in the pressure chamber.It is characterized by that.
[0009]
  According to the present invention, the viscous material stored in the pressurizing chamberInIs, DThe pressure is efficiently and evenly transmitted to the viscous material, the responsiveness from the start of air pressure to the start of discharge is improved, and the viscous material can be discharged instantaneously with an appropriate discharge amount. And since the residual pressure does not remain in the pressurizing chamber even after the completion of the discharge, it is possible to prevent the viscous material from dropping from the discharge port and adhering to the coated object at the time of re-application as in the prior art. In particular, it is less susceptible to viscosity resistance in the case of high-viscosity viscous materials, so that even in the case of screen printing in which printing paste is applied in a straight line, uniform ejection can be performed, for example, improved dispensing accuracy and high efficiency in general viscous material application Can be achieved.
[0010]
The discharge pressure adjusting means includes an air bag that is provided in the pressure chamber and whose internal volume increases or decreases with intake and exhaust, and an air supply unit that adjusts and supplies compressed air to the air bag. It is preferable that the air bag is deformed with the air intake / exhaust between the air supply unit and the pressurizing chamber, so that the discharge pressure can be easily adjusted by increasing / decreasing the volume in the pressurizing chamber. In this case, the closer the position of the air bag in the pressurized chamber is to the discharge port, the more the difference between the discharge air pressure and the discharge pressure disappears, and the responsiveness can be further improved.
[0011]
The discharge pressure adjusting means is preferably constituted by an actuator such as an air cylinder or a voice coil motor, and a diaphragm which is deformed thereby to increase or decrease the volume in the pressurizing chamber.
[0012]
Further, in correspondence with a plurality of viscous material supply means arranged in series, one pressurizing chamber, a discharge pressure adjusting means and a discharge port are shared and used at a discharge position along the arrangement direction of the viscous material supply means. It is preferable that the discharge pressure of the viscous material is adjusted at once. According to this configuration, in the screen printing as described above, it is possible to discharge the high-viscosity printing paste uniformly and accurately regardless of the discharge position.
[0013]
It is preferable to use a plurality of discharge pressure adjusting means to arbitrarily adjust the discharge pressure of the viscous material at the discharge position, and local pressure adjustment can be easily performed.
[0014]
In addition, by attaching a pair of inclined plates on both sides of the lower part of the pressurizing chamber so that they approach each other downward, and by using the lower end opening as a discharge port, the inclined plate can be used for the squeegee in the screen printing. Instead, the printing paste can be properly filled into the screen opening by adjusting the discharge pressure, so that high-precision printing can be achieved and the printing quality can be improved.
[0015]
In the above configuration, according to the configuration not limited to the supply by pressure feeding from the viscous material supply means for feeding the viscous material, the apparatus main body can be easily replaced, or the cartridge filled with the viscous material is accommodated in the apparatus main body. By making it possible, the viscous material can be stored in the pressurizing chamber, and the pressure member for supplying the viscous material becomes unnecessary, and the viscous material supply can be facilitated.
[0016]
It is preferable that a soft elastic material is sandwiched between the inclined plates and the lower side surface of the pressurizing chamber. If comprised in this way, when an inclined board is pressed on a screen, an adhesiveness with a screen can be improved because an inclined board bends. Accordingly, when the viscous material is supplied into the pressurizing chamber or when the viscous material in the pressurizing chamber is pressurized, it is possible to prevent the viscous material from coming out between the inclined plate and the screen. However, in order to further improve the adhesion, it is necessary to increase the deflection of the inclined plate. For this purpose, it is necessary to increase the length of the inclined plate. If it does so, the volume of a pressurization chamber will increase and the viscous material to supply will increase, supply time will increase, and the coating unit weight will increase. Therefore, by sandwiching the soft elastic material between the inclined plate and the lower side surface of the pressurizing chamber, the volume of the pressurizing chamber can be reduced while ensuring the deflection of the inclined plate, and the viscous material can be minimized. . The soft elastic material is configured along the inclined plate, but may be connected at both ends of the inclined plate, or another soft elastic material may be put at both ends of the inclined plate. When a large amount of viscous material may be used, the soft elastic material does not have to be formed along the inclined plate, and the soft material may be put only at both ends of the inclined plate.
[0017]
Further, when the supply pressure of the viscous material supply means is turned off after the pressure chamber is filled with the viscous material by the viscous material supply means, the viscous material filled in the pressure chamber has some pressure even if the supply pressure is turned off. It is preferable that the pressure in the pressurizing chamber is reduced by absorbing the residual pressure of the supply pressure remaining in the pressurizing chamber with the air bag. Thereby, the residual pressure in the pressurizing chamber can be eliminated, and the discharge pressure can be controlled by the air bag.
[0018]
Further, by providing at least one pressure detecting means between the end of the pressure chamber or the viscous material supply means, the viscous material is supplied into the pressure chamber when the viscous material is supplied to the pressure chamber by the viscous material supply means. It is preferable that the pressure detection means detects that the battery is full.
[0019]
Further, when the pressure chamber is pressurized by the discharge pressure adjusting means, if the pressure detected by the pressure detecting means does not reach the predetermined pressure, it is determined that the viscous material is insufficient, and the viscous material is supplied by the viscous material supplying means. It is preferable that the viscous material in the pressure chamber can be replenished.
[0020]
It is preferable that the pressure of the discharge pressure adjusting means is adjusted by moving while being pressurized by the discharge pressure adjusting means and detecting the pressure in the pressurizing chamber by the pressure detecting means.
[0021]
Further, it is preferable that the pressurizing chamber is provided with a rotatable shaft, and the viscous material is caused to flow by rotating the shaft.
[0022]
Further, it is preferable that the viscous material is collected in the pressurizing chamber by making the pressure of the pressurizing chamber negative by the discharge pressure adjusting means and raising the pressure chamber while moving the pressurizing chamber horizontally.
[0023]
Further, it is preferable that the temperature of the viscous material is stabilized by replacing the air in the air bag.
[0024]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a viscous material coating apparatus according to an embodiment of the present invention will be described with reference to FIGS.
[0025]
The viscous material application apparatus according to the first embodiment shown in FIG. 1 mainly includes a material supply unit 1, an air supply unit 2, and an application unit 3 that is an apparatus main body. In the material supply unit 1, a viscous material 5 such as an adhesive or cream solder is accommodated in a syringe-like accommodation tank 1b, and the plunger 1a is actuated by the compressed air for material supply to pressurize and apply the viscous material 5 The unit 3 is pressurized so that the inside of the chamber (pressure chamber) 3c is always filled.
[0026]
The coating unit 3 and the material supply unit 1 are connected by a joint 6, and a through hole 6a provided in the joint 6 is provided so as to communicate with a viscous material supply passage 3d provided horizontally on the side of the chamber 3c. As a result, the viscous material 5 is supplied into the coating unit 3.
[0027]
A discharge nozzle 4 b extends from the discharge unit 4 below the coating unit 3. On the other hand, an air supply unit 2 is disposed above the coating unit 3, and compressed air for material supply adjusted to a predetermined pressure is supplied from the air supply unit 2 to the entire upper space in the chamber 3c via the air port 3a. It is sent to the provided air bag 3b. In the first embodiment, the air bag 3b and the air supply unit 2 constitute discharge pressure adjusting means.
[0028]
The air bag 3b is formed from a bag-like container made of nylon or rubber having a thickness of about 0.03 mm to 0.05 mm, for example. In addition, it is preferable to use a solvent-resistant material in consideration of the composition of the viscous material 5.
[0029]
The air bag 3b is arbitrarily expanded and contracted in accordance with intake / exhaust due to inflow of compressed air from the air supply unit 2 and outflow to the air supply unit 2, thereby increasing or decreasing the volume of the chamber 3c in the coating unit 3. ing. As a result, the viscous material 5 in the chamber 3c can be extruded or pulled at a predetermined pressure. Further, the responsiveness is improved by shortening the distance from the air bag 3b to the discharge port 4a to about 10 mm, for example.
[0030]
As shown in the graph of FIG. 2A, there is no waiting time from when the discharge is turned on until the pressure is actually applied, and there is no residual pressure at the end of the discharge. According to the experiment, the predetermined pressure sent from the air supply unit 2 can be instantaneously reached in about 0.3 seconds to 0.5 seconds. Even when the discharge is turned off, the residual pressure in the chamber 3c after the pressurization is instantaneously reduced to near zero, and the discharge can be stopped. Further, in the first embodiment, since the distance between the air bag 3b and the discharge port 4a at the tip of the discharge nozzle 4b is short, the air pressure of the compressed air supplied from the air supply unit 2 to the air bag 3b and the viscosity discharged from the discharge port 4a. As shown in the graph of FIG. 2B, it has been confirmed by a comparative experiment with a conventional example that the discharge pressures of the materials are substantially equal. Thus, in the first embodiment, the pressure transmission efficiency is improved by the function of adjusting the discharge pressure by the expansion and contraction action of the air bag 3b in conjunction with the supply and exhaust action of the air supply unit 2, and the viscous material stored in the chamber 3c is improved. 5 can be reduced. Note that the exhausting action of the air supply unit 2 is realized by opening the air in the air bag 3b to the atmosphere or sucking it.
[0031]
In the second embodiment shown in FIG. 3, an air cylinder 7 and a post-diaphragm 7b interlocked with the air supply unit 2 are used instead of the air bag 3b for adjusting the discharge pressure. The air cylinder 7 is provided with a piston 7a, and compressed air adjusted to a predetermined air pressure is supplied from the air supply unit 2 from the air port 3a. As a result, the piston 7a moves up and down and is attached to the lower end of the diaphragm. 7b is deformed. Due to the deformation of the diaphragm 7b, the volume of the chamber 3c is increased or decreased to increase or decrease the pressure of the viscous material 5. As the diaphragm 7b, a bellows or the like can be used in addition to the illustrated one.
[0032]
In the third embodiment shown in FIG. 4, an electric motor called a voice coil motor (VCM) 8 that drives the piston 7a is used to adjust the discharge pressure. In the third embodiment, the mechanism for increasing / decreasing the volume in the chamber 3c by deformation of the diaphragm 7b is the same as in the second embodiment, but a faster response can be realized by making the drive electric. The operating distance (stroke) of the voice coil motor 8 is controlled by attaching a pressure sensor 19 near the tip of the chamber 3c and the piston 7a and comparing the detected value with a set value, or a resistance value generated during operation. It is also possible to read (resistance force) from the driver of the voice coil motor 8 and convert it into pressure, thereby controlling it. In any case, in order to transmit the pressure efficiently and instantly, it is necessary to make the distance between the drive source serving as the discharge pressure adjusting means and the diaphragm 7b and the discharge port 4a as small as possible.
[0033]
In the fourth embodiment shown in FIG. 5, the discharge pressure is adjusted by the discharge pressure adjusting means similar to that of the air bag shown in the first embodiment. By sharing the tube-shaped air bag 11b, the discharge pressure within a predetermined volume is collectively adjusted by a set of discharge pressure adjusting means.
[0034]
Specifically, as shown in reference diagrams (a) to (e) of FIG. 6, flat plate holes for printing a viscous material (print paste) 31 on the land pattern 33 of the circuit board 32 in order to mount electronic components. In a printing apparatus such as a plate type (screen type), a thin plate blade (tilted plate) 12 described later is used instead of the squeegee 37 used when filling the opening 35 of the screen 34 disposed on the circuit board 32 with the viscous material 31. The case where the said discharge pressure adjustment means is operated is shown. That is, the viscous material application apparatus of the fourth embodiment is used as a print head of a screen printing machine.
[0035]
According to the fourth embodiment, in the printing process of filling the viscous material 31 into the opening 35 of the screen 34, the viscous material 31 is disposed at one location on one side with the air bag 11b disposed in the arrangement direction of the discharge pressure adjusting means 1. Highly accurate discharge pressure that keeps the filling pressure of the viscous material 31 into the opening 35 at an appropriate value by increasing / decreasing the volume of the chamber 11a by the intake / exhaust operation in conjunction with the discharge pressure adjusting unit (air supply unit) 2 Adjustments can be made to improve print quality. The length of this viscous material applicator is 270 mm, and the viscous material 31 is accommodated in the viscous material supply unit 1 disposed at intervals of 85 mm in the center and each of the left and right parts. The viscous material 31 is pumped from the through hole 9a having a diameter of about 6 mm in the joint 9 connected to the viscous material supply unit 1 to the chamber 11a in the coating unit 11. An air port 11d for supplying compressed air from the air supply unit 2, a joint 11e, and an air bag 11b are arranged in the chamber 11a.
[0036]
Inside the air bag 11b, a shaft 11g and an air holed pipe 11f for air intake / exhaust are attached. Since the discharge port 14 has a long length of 270 mm in the shaft 11g, the air bag 11b made of a nylon tube having a thickness of 0.05 mm is deformed and prevents the air bag 11b from protruding from the chamber 11a. It is provided to send air instantly. The joint 11e is connected to the pipe 11f. The nylon of the air bag 11b has a diameter of about 10 mm and a length of about 220 mm, and is connected to the joint 11e using an O-ring or the like without causing air leakage.
[0037]
Two thin blades 12 made of 0.3 mm thick copper thin blades are attached to both ends of the lower portion of the chamber 11a with a blade retainer 10 so as to approach each other downward with a distance of about 10 mm. It is an alternative to conventional squeegees in screen printing. In the fourth embodiment, the opening between the thin blades 12 and 12 forms the discharge port 14, and the viscous material 31 is discharged from the discharge port 14. The side plate 13 is fixed to the chamber 11a with a side stopper 15 such as urethane rubber interposed therebetween so that the viscous material 31 does not leak from the chamber 11a.
[0038]
In the viscous material application apparatus in which the three viscous material supply units 1 are arranged as described above, the one using the discharge pressure adjusting means (the discharge pressure adjusting means 2 and the air bag 11b) as in the fourth embodiment, and the viscous material FIG. 7 and FIG. 8 show data results of a comparative experiment in the case of screen printing with a conventional device that discharges the viscous material 31 using only compressed air for material supply of the supply unit 1.
[0039]
First, in the comparison of the pressure variation at the three measurement positions in the longitudinal direction of the central part and the left and right parts, the air pressure is about 0.2 kgf / cm.²In the fourth embodiment, the variation in the fourth embodiment is about 0.01 kgf / cm as shown in FIG.²It was almost negligible. However, in the conventional case, as shown in FIG. 7B, about 0.1 kgf / cm.²There was also a degree.
[0040]
Next, the responsiveness of the discharge pressure is compared in FIGS. The rise time of the filling pressure is about 0.3 seconds in the fourth embodiment as shown in FIG. 8A, whereas it is about 10 in the conventional case as shown in FIG. 8B. More than a second. Further, even after the pressurization is completed, in the conventional one, the residual pressure in the chamber 11a is about 0.3 kgf / cm.²In contrast, in the fourth embodiment, the pressure in the chamber 11a is instantaneously reduced, while a pressure of about a level remains, and it takes about 30 seconds from the start of discharge to the pressure. This is because after the pressurization is completed, the residual pressure remaining in the chamber 11 a is sucked by the air bag 11 b contracting and exhausting to the air supply unit 2.
[0041]
Moreover, as shown in FIG. 9, you may devise so that the plate 11h may be stuck on the top surface of the viscous material 31 which the air bag 11b in 4th Embodiment presses, and the viscous material 31 in the chamber 11a may spread uniformly.
[0042]
In the viscous material application apparatus of the fourth embodiment described above, the viscous material 31 is pressurized with high accuracy and uniformity in the chamber 11a, and the viscous material 31 discharged from the discharge port 14 is in the longitudinal direction of the discharge port 14. Is uniformly applied. However, in the fifth embodiment shown in FIG. 10, the discharge pressure can be changed for each application position.
[0043]
According to 5th Embodiment, as shown to Fig.10 (a), the viscous material supply part 1 is provided in two places, and the air bags 3f, 3e, and 3g are provided in three places, a center part, a left part, and a right part. The air ports 3 a communicating with the air supply unit 2 are separately arranged. If the viscous material to be discharged is a viscous material having a high viscosity of about 200 Pa · s such as a printing paste, for example, the air pressure of the compressed air from the left and right air supply units 2 is 0.5 kgf / cm.², 0.3kgf / cm at the center²As shown in FIG. 10 (b), the discharge pressure from the chamber 11a can be locally adjusted at the left, right, and center. Further, in order to accurately adjust the local pressure, the chamber 3c can be partitioned corresponding to the air supply unit 2.
[0044]
Further, not only the plurality of air bags 3e, 3f, 3g are arranged in series as described above, but the same application is achieved by arranging a plurality of air bags 3b in parallel as in the sixth embodiment shown in FIG. A pressure distribution can be arbitrarily created by changing the discharge pressure in the unit 3. FIG. 11B is a graph showing the pressure distribution.
[0045]
FIG. 12 shows the suction action of the viscous material 31 when the viscous material 31 is discharged from the viscous material application device and applied to the object 32 and then the discharge port 14 is separated from the object 32. This is shown in the apparatus of the fifth embodiment. In this case, the viscous material 31 in the vicinity of the discharge port 14 is torn between the coating object 32 and the discharge port 14, a part of the viscous material 31 b is applied on the coating object 32, and the other viscous material 31 a is discharged. It hangs down from the outlet 14. However, as shown in FIG. 12B, by sucking the air in the air bag 11b through the air holed pipe 11f in this state, the air bag 11b further contracts, and the hanging viscous material 31a is removed from the chamber 11a. It will be brought back in.
[0046]
That is, when the viscous material application device is again disposed on the workpiece 32, the viscous material 31 adheres to the periphery of the discharge port 14 (opening surface of the chamber 11a) in the state of FIG. However, if the viscous material 31 that hangs down as shown in FIG. 12B is sucked into the chamber 11a by air suction as described above, the discharge port 14 is disposed on the workpiece 32 for reprinting. Further, the viscous material 31 does not protrude and the object 32 can be made clean. The pressure for the suction is supplied from the air supply unit 2, and the pressure necessary for the suction may be such that the air bag 11b contracts, and is about minus 0.2 to 0.3 kgf / cm.²Is preferred.
[0047]
FIG. 13 shows a seventh embodiment. In the embodiment described above, the viscous material 5 is supplied to the chamber 3c formed in the coating unit 3 by the compressed air for material supply, but the supply means is not limited to this. For example, in the seventh embodiment, the application unit 3 is detachably formed from the air bag 3b, and the viscous material 5 is supplied by replacing it with a new application unit 3 filled with the viscous material 5. Alternatively, the cartridge 3h formed so as to be housed in the chamber 3c may be replaced. In this case, the viscous material 5 is supplied by the cartridge 3 h, and the internal space forms a chamber (pressurizing chamber) in the coating unit 3. The material of the cartridge 3h may be made of nylon, fluorine, metal / nonmetal, etc., as long as it can be accommodated in the chamber 3c.
[0048]
In the eighth embodiment shown in FIGS. 14 (a) and 14 (b), the discharge pressure is adjusted by the same discharge pressure adjusting means as the air bag 11b shown in the fourth embodiment. The chamber 11a and the air bag 11b are arranged and the discharge pressure within a predetermined volume is collectively adjusted by a set of discharge pressure adjusting means. The lower side surface of the chamber 11a and the thin blade (inclined plate) ) The soft elastic material 38 is sandwiched between 12.
[0049]
Even when there is no soft elastic material 38, when supplying the viscous material 31 to the chamber 11a or pressurizing the viscous material 31 in the chamber 11a, the application unit 11 is pressed against the screen and the thin blade 12 is bent. Adhesion with the screen can be improved, and the viscous material 31 can be prevented from coming out between the thin blade 12 and the screen. However, in order to improve the adhesion and follow the screen swell, it is necessary to increase the length of the thin blade 12 and increase the deflection of the thin blade 12. However, as described above, the volume of the chamber 11 a increases and the amount of the viscous material 31 to be supplied increases, which increases the supply time and the weight of the coating unit 11.
[0050]
Therefore, by sandwiching the soft elastic material 38 between the thin blade 12 and the lower side surface of the chamber 11a, the volume of the chamber 11a can be reduced while securing the deflection of the thin blade 12, and the amount of the viscous material 31 is minimized. Can be. The soft elastic material 38 is formed along the thin plate blade 12, but may be connected at both ends of the thin plate blade 12 as shown by 38a in FIG. 15 (a), and the thin plate as shown in FIG. 15 (b). A pair of left and right soft elastic materials 38b along the blade 12 and another pair of soft elastic materials 38c may be placed at both ends of the thin plate blade 12. When the viscous material 31 may be large, the soft elastic material 38 may not be formed along the thin blade 12, and the soft elastic material 38 may be put only at both ends of the thin blade 12. The soft elastic material 38 may be fixed to the chamber 11a, but may be sandwiched between the chamber 11a and the thin plate blade 12 or both ends of the thin plate blade 12 with another plate. Further, it is possible to ensure the deflection of the thin blade 12 by reducing the thickness of the thin blade 12 or using a resin material.
[0051]
As described above, when the present embodiment is used as a printing head of a screen printing machine, it is possible to follow the screen swell by taking a large deflection of the thin blade 12, and there is no circuit board under the screen. Also, the viscous material 31 can be scraped off with the thin blade 12.
[0052]
In addition, the application unit 11 during printing usually has a structure that freely moves up and down in order to follow the screen. However, in order to effectively use the deflection of the thin blade 12, the movement of the application unit 11 in the vertical direction is performed. It is preferable that the thin plate blade 12 moves up and down to scrape the viscous material 31.
[0053]
The soft elastic material 38 is soft and solvent-resistant. For example, low-hardness polyethylene or urethane rubber is suitable, but silicon rubber, especially foamed silicone rubber, is also soft if it is regularly replaced. Therefore, it is preferable. Moreover, it is preferable to bond or coat a material having a high hardness such as a fluorine-based material on the surface of the soft elastic material 38 facing the screen so that the sliding is good and the life is extended.
[0054]
Next, in FIGS. 16A and 16B, the pressure in the chamber 11a is compared. When the supply pressure of the viscous material supply unit 1 is turned off after the chamber 11a is filled with the viscous material 31 by the viscous material supply unit 1, the viscous material 31 filled in the chamber 11a even when the supply pressure is turned off is shown in FIG. ) (Hereinafter referred to as residual pressure), and this residual pressure does not drop extremely even after several minutes. Although the discharge pressure is generated by the air bag 11b, the discharge pressure can be controlled by the air bag 11b when the residual pressure <discharge pressure, but it is difficult to control the discharge pressure when the residual pressure> discharge pressure.
[0055]
Therefore, when the supply pressure is applied to the viscous material supply unit 1 or during the supply, the air bag 11b is inflated, and when the chamber 11a is filled with the viscous material 31 and the supply pressure is turned off, the air in the air bag 11b is also turned off. The residual pressure in the chamber 11a can be absorbed by the air bag 11b being deflated, and the residual pressure in the chamber 11a can be instantaneously reduced in a time of 1 second or less as shown in FIG. This eliminates the pressure in the chamber 11a, and the discharge pressure can be controlled by the air bag 11b.
[0056]
At this time, as shown in FIG. 17 (a), the chamber 11a and another room 11m (in this case, both the 11a and 11m have the pressurizing chamber of the present invention not to disturb the movement of the viscous material 31 in the chamber 11a. The same effect can be obtained even if the air bag 11b is provided at the upper portion of the chamber 11a. The conventional air bag 11b has a circular cross section (FIG. 17 (a)). However, as shown in FIG. 17 (b), an air bag 39a that accumulates air on a sheet-like material or as shown in FIG. 17 (c). Even if the air bag 39b that accumulates air in the bag-shaped object is used, the same effect as before can be obtained. By applying these, as shown in FIG. 19 (d), the same applies even if an elastic material bag (air bag) 39c is used so that the pressurizing chamber (chamber) 11a is formed in a bag shape and the place where air enters is made into a room. An effect can be obtained.
[0057]
Next, as shown in FIG. 18, when the viscous material 31 is supplied into the chamber 11a, the air reservoir 40a may remain in the chamber 11a even when the chamber 11a is full. Since the pressure inside the chamber 11a is evenly applied by the air bag 11b, the same pressure is also applied to the air reservoir 40a, which is not a big problem. However, in order to control the pressure more precisely, air is released from minute holes or slits. If 40 is provided, the air in the air reservoir 40a is discharged. At this time, since the hole or slit is very small, resistance is large for the viscous material 31 to go out, and it does not come out of the air vent 40.
[0058]
Next, full detection of the viscous material 31 in the chamber 11a will be described with reference to FIG. When supplying the viscous material supply unit 1 with the supply pressure and supplying the viscous material 31 to the chamber 11a, the supply pressure may be applied for a predetermined time, but at least between the end in the chamber 11a or the viscous material supply unit 1 By providing one pressure detecting means 41, it is possible to detect by the pressure detecting means 41 that the viscous material 31 is full in the chamber 11a.
[0059]
A method for supplying the viscous material 31 during printing will be described with reference to FIG. The method of initially supplying the viscous material 31 into the chamber 11a is performed as described above. When the chamber 11a is full, the air bags 11b, 39a, 39b, and 39c (hereinafter referred to as 11b only) are inflated for printing. Although the viscous material 31 is gradually reduced by printing, a predetermined pressure can be generated in the chamber 11a while the air bag 11b is inflated, and printing can be performed.
[0060]
When the air bag 11b is inflated to make up for the reduced volume of the viscous material 31, the pressure in the chamber 11a decreases and becomes a lower limit pressure required for printing set in advance. By detecting the lower limit pressure in the chamber 11a by the pressure detection means 41, the decrease in the viscous material 31 is detected, and by performing the same operation as the initial supply, the viscous material 31 is supplied again into the chamber 11a, thereby Printing can be continued by inflating the bag 11b and generating discharge pressure.
[0061]
At this time, if there is no problem in the residual pressure in the chamber 11a, the operation of only the supply pressure unit 1 may be performed. However, if the residual pressure becomes a problem, the residual pressure needs to be removed by the air bag 11b.
[0062]
Further, when the supply timing of the viscous material 31 is known in advance, the viscous material 31 may be supplied at a set timing such as the number of printings without detecting the lower limit pressure, or when the viscosity of the viscous material 31 is low The viscous material 31 may be supplied little by little while always applying a low supply pressure.
[0063]
In FIG. 21, the pressure in the chamber 11a during printing will be described. By inflating the air bag 11b, the pressure in the chamber 11a can be instantaneously increased, and printing is performed by moving the coating unit 11 as it is. At this time, because the application unit 11 moves, the viscous material 31 in the chamber 11a moves in the chamber 11a, so that the pressure detected by the pressure detection means 41 is lower than when the application unit 11 is stopped.
[0064]
If the opening of the screen is such that the pressure difference does not become a problem, the air bag 11b may be inflated at a predetermined pressure. Otherwise, the pressure during actual printing is also detected and the coating unit 11 is stopped. The moving state of the viscous material 31 is considered from the pressure difference in the chamber 11a during the movement. In particular, when the pressure difference in the chamber 11a is large, the viscous material 31 is likely to move, that is, the viscosity is often lowered, so the pressure of the air bag 11b is reset according to the degree of pressure drop.
[0065]
This resetting of the pressure corrects the relationship with the viscosity of the viscous material 31, so that it can be automatically reset even during printing if the relationship between the viscosity, the detected pressure and the set pressure is determined in advance. Even if the viscosity of the viscous material 31 changes due to temperature change or continuous use, stable printing is realized by resetting the pressure of the air bag 11b by comparing with the pressure measured during the previous printing. be able to.
[0066]
Further, by applying pressure to the air bag 11b before the start of printing and moving the coating unit 11 where there is no screen opening, the pressure of the air bag 11b can be reset without actually performing printing.
[0067]
Further, as shown in FIG. 22, by providing a plurality of pressure detecting means 41 around the inside of the chamber 11a, the pressure state of the viscous material 31 can be detected more precisely, and the movement of the viscous material 31 in the chamber 11a. Can be detected. If the pressure difference of the pressure detection means 41 is large, the movement of the viscous material 31 is bad, that is, the viscosity is high, and the pressure of the air bag 11b (39a) is set high. If the pressure difference of the pressure detection means 41 is small, the viscosity is low. It can be said that the movement of the material 31 is good, that is, the viscosity is low, and the pressure of the air bag 11b can be set low.
[0068]
Next, a method for promoting the flow of the viscous material will be described with reference to FIG. As shown in FIG. 23A, when the viscous material 31 filled in the chamber 11a moves on the screen 34 with the discharge pressure applied, the viscous material 31 flows in the same direction as the moving direction. When no discharge pressure is applied, this flow does not occur, and the viscous material 31 slides on the screen 34, and the viscous material 31 is difficult to enter the opening of the screen 34 and cannot be printed. That is, when the viscous material 31 flows, the viscous material 31 enters the opening of the screen and can be printed.
[0069]
As shown in FIG. 23B, this is the same as the case of printing using the squeegee 37. When the squeegee 37 moves, the viscous material 31 also flows in the same direction.
[0070]
In the case of this squeegee method, in order to promote the fluidity of the viscous material 31, the viscous material 31 is often agitated in advance in the container before the viscous material 31 is supplied to the squeegee 37. .
[0071]
When the viscous material 31 is in the chamber 11a as in the present invention, the viscous material 31 cannot be stirred in advance, but considering that the viscous material 31 in the chamber 11a flows by performing a printing operation, It is clear that the viscous material 31 can be agitated by the reciprocating operation of the coating unit 11 on the screen 34 while the discharge pressure is applied before the start of printing, and performing the operation before printing stabilizes the printing. It is suitable for the purpose.
[0072]
Further, when it is necessary to mix the viscous material 31, as shown in FIGS. 24A and 24B, the viscous material 31 can be mixed by providing the shaft 42 in the chamber 11a and rotating it. . The shaft 42 is in the chamber 11 a and is supported at both ends, thereby preventing the viscous material 31 from leaking through the O-ring 43. A pulley 44 is fixed to at least one of the shafts 42 and is connected to a motor 46 through a belt 45. That is, when the motor 46 is rotated, the shaft 42 is rotated, and the viscous material 31 can be forcibly mixed.
[0073]
As shown in FIG. 25, when the viscous material 31 is viewed from the aspect of viscosity, the viscosity is gradually decreased because it flows every time the printing operation is performed. By reciprocating the coating unit (printing head) 11, the viscosity of the viscous material 31 can be lowered to some extent in advance, and by using the shaft 42, the viscosity is further lowered and the viscosity material 31 of the viscous material 31 by printing is subsequently printed. Viscosity change can be reduced. Needless to say, rotating the shaft 42 during the reciprocating operation of the print head 11 is more effective.
[0074]
Next, the flow rate of the viscous material 31 in the chamber 11a will be described with reference to FIGS. The viscous material 31 at the time of printing has the discharge port 4a at the maximum speed as indicated by the arrow in FIG. When the viscosity of the viscous material 31 is high, the viscous material 31 is difficult to flow, and therefore its speed is reduced. Due to this, the speed of the discharge port 4a is reduced and does not match the speed of the print head 11, resulting in the viscosity of the screen 34 and the viscosity. The material 31 slips and is difficult to print. Further, when the printing speed is high, the speed of the discharge port 4a tends to increase, but the viscosity of the viscous material 31 in the chamber 11a becomes resistance and the speed of the discharge port 4a does not increase. The viscous material 31 slips and printing becomes difficult.
[0075]
As shown in FIG. 26B, since the flow of the viscous material 31 in the chamber 11a can be promoted by rotating the shaft 42 configured in the chamber 11a even during printing, the viscosity of the viscous material 31 is increased. Even when the printing speed is high or the printing speed is high, the speed of the discharge port 4a can be increased. As a result, the screen 34 and the viscous material 31 do not slip and can be printed.
[0076]
Of course, it is possible to make the shaft 42 free and follow the flow of the viscous material 31. It is also possible to measure the viscosity by attaching a strain gauge or the like to the end axis of the shaft 42, but forcibly the shaft 42. It is more effective to rotate.
[0077]
Next, a method of separating the print head (application unit) 11 from the screen 34 without leaving the viscous material 31 on the screen will be described with reference to FIGS. As shown in FIG. 27A, the viscous material 31 is in the chamber 11a of the print head 11, and the viscous material 31 is in contact with the screen 34 at the discharge port 4a. As shown in FIG. 27B, if the print head 11 is lifted as it is, a large amount of the viscous material 31 remains on the screen 34. Further, as shown in FIG. 27C, as in the case of preventing the dripping of the viscous material 31 from the discharge port 4a, even if the print head 11 is lifted after the air bag 11b is deflated, it is still on the screen 34. The viscous material 31 remains. Since the remaining viscous material 31 is troublesome to reuse, all the viscous material 31 on the screen 34 must be collected in the print head 11.
[0078]
In the present invention, as shown in FIG. 27C, the air bag 11b can be squeezed to reduce the volume in the chamber 11a. Therefore, as shown in FIG. The viscous material 31 on the screen 34 is scraped off by the thin blade 12 and is moved upward as shown in FIG. 27E while moving the print head 11 as it is to leave the viscous material 31 on the screen 34. First, the print head 11 can be separated from the screen 34.
[0079]
Next, a method for quickly returning the coating unit 11 to room temperature will be described with reference to FIGS. The viscous material 31 in use is stored in a refrigerator or the like by covering the normal application unit 11 when production is stopped. When production is resumed, the temperature of the viscous material 31 needs to be returned to room temperature, and must be taken out of the refrigerator 30 minutes or more before normal production as shown in FIG. If the viscous material 31 is frequently replaced, it takes time and effort to bring the viscous material 31 to room temperature.
[0080]
In the present invention, the temperature of the viscous material 31 can be quickly returned to room temperature as shown in FIG. 28C by replacing the air in the air bag 11b as shown in FIG. It is possible to start with no extra effort and time.
[0081]
【The invention's effect】
As described above, according to the present invention, the discharge pressure adjusting means disposed in the vicinity of the discharge port efficiently transmits pressure when discharging the viscous material stored in the pressurizing chamber, and is instantaneously appropriate and uniform. With a high discharge pressure, discharge can be performed efficiently and with high accuracy. Especially when used for screen printing, leakage of viscous materials and occurrence of bridges are prevented by increasing the accuracy of the filling pressure to the screen opening. The print quality can be improved.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing a viscous material applying apparatus according to a first embodiment of the present invention.
2A and 2B show experimental data in the embodiment, where FIG. 2A is a graph showing the response of the discharge pressure, and FIG. 2B is a graph showing the efficiency of the discharge pressure in comparison with the prior art.
FIG. 3 is a longitudinal sectional view showing a second embodiment of the present invention.
FIG. 4 is a longitudinal sectional view showing a third embodiment of the present invention.
FIG. 5A is a front view and FIG. 5B is a side view showing a fourth embodiment of the present invention.
6 is a reference diagram of the embodiment, and is an explanatory diagram illustrating a process of applying a printing paste (viscous material) by screen printing in the order of (a) to (e). FIG.
7A and 7B show data comparing discharge pressure variations with a conventional example, FIG. 7A is a graph showing data of the embodiment, and FIG. 7B is a data graph of the conventional example.
8A and 8B show data obtained by comparing discharge pressure responsiveness with a conventional example, FIG. 8A is a graph showing data of the embodiment, and FIG. 8B is a graph showing data of a conventional example.
FIG. 9 is a longitudinal side view showing a modification of the embodiment.
10A is a longitudinal sectional view of a fifth embodiment of the present invention, and FIG. 10B is a graph showing a discharge pressure distribution of the embodiment.
11A and 11B show a sixth embodiment of the present invention, in which FIG. 11A is a perspective view schematically showing an essential part thereof, and FIG. 11B is a graph showing a discharge pressure distribution of the embodiment;
FIGS. 12A and 12B show the operation of the present invention in the fourth and fifth embodiments, wherein FIG. 12A is a longitudinal sectional view showing a state immediately after the end of discharge of a viscous material, and FIG. The longitudinal cross-sectional view which shows the state which adjusted the pressure.
FIG. 13 is a longitudinal sectional view for explaining a main part of a seventh embodiment of the present invention.
14A and 14B show an eighth embodiment of the present invention, in which FIG. 14A is a longitudinal sectional view thereof, and FIG. 14B is a transverse sectional view thereof.
FIG. 15 is a perspective view showing an integrated type of a soft elastic material in (a) and a split type in (b).
FIG. 16 is a graph shown in (a) and (b) of removing the residual pressure in the pressurized chamber with an air bag.
FIG. 17 is a cross-sectional view showing various aspects of the air bag in (a), (b), (c), and (d).
FIG. 18 is an explanatory view showing a slit for removing air.
FIG. 19 is an explanatory view showing a pressure detecting means in the pressurizing chamber.
FIG. 20 is a graph showing the pressure in the pressurizing chamber when initial supply and additional supply are performed.
FIG. 21 is a graph showing the pressure in the pressurizing chamber during printing.
FIG. 22 is an explanatory view showing a pressure detection means in the pressurizing chamber.
FIG. 23 is a diagram showing the flow of a viscous material in (a) and (b).
FIG. 24 shows an example in which a shaft is arranged in the pressurizing chamber, (a) is a longitudinal sectional view thereof, and (b) is a left side view thereof.
FIG. 25 is a graph showing a change in viscosity of a viscous material.
FIG. 26 is a diagram showing the flow velocity distribution of the viscous material in (a) and (b).
FIGS. 27A and 27B are views showing the operation of collecting the viscous material on the screen, as shown in (a), (b), (c), (d), and (e).
FIGS. 28A and 28B are diagrams for explaining that the viscous material is quickly returned to room temperature, in which FIG. 28A is a longitudinal sectional view, and FIGS. 28B and 28C are graphs.
FIG. 29 is a schematic perspective view showing two types of conventional examples (a) and (b).
FIG. 30 is a graph showing data of discharge pressure response in the conventional example.
FIGS. 31A and 31B are schematic perspective views showing two types of multiple conventional nozzles in FIGS.
32 is a graph shown in (a) and (b) of discharge pressure data from each of the multiple nozzles of the conventional example, corresponding to the measurement points in (a) and (b) of FIG. 31;
[Explanation of symbols]
1 Material supply section (viscous material supply means)
2 Air supply part (Discharge pressure adjusting means)
3, 11 Application unit (apparatus body, print head)
3b, 11b, 39a, 39b, 39c Air bag (discharge pressure adjusting means)
3c, 11a, 11m Chamber (Pressurizing chamber)
3h cartridge (viscous material supply means)
4a Discharge port
5 Viscous material
7 Air cylinder (Discharge pressure adjusting means)
7a Piston (Discharge pressure adjusting means)
7b Diaphragm (Discharge pressure adjusting means)
8 Voice coil motor (Discharge pressure adjusting means)
12 Thin blade (inclined plate)
31 Printing paste (viscous material)
38 Soft elastic material
41 Pressure detection means
42 Shaft

Claims (11)

A pressure chamber having a discharge opening,
An air bag provided in the pressurized chamber ;
A viscous material supply means for supplying a viscous material between the inner wall of the pressurizing chamber and the air bag ;
A discharge pressure adjusting means for adjusting the discharge pressure of the viscous material supplied the pressure chamber,
Viscous material application apparatus , comprising: air adjusting means for adjusting the amount of air in the air bag based on the pressure of the viscous material in the pressurizing chamber . The viscous material coating apparatus according to claim 1 , wherein the entire surface of the air bag has a gap with the pressurized chamber wall . The discharge port further includes a pair of inclined plates,
The inclined plate, the pressure chamber viscous material application device according to claim 1 or 2, characterized in that the respectively arranged to proximity with distance from. 4. The viscous material applying apparatus according to claim 1, further comprising a plurality of viscous material supply means for supplying the viscous material to the pressurizing chamber . 5. The viscous material coating apparatus according to claim 1, comprising a plurality of air supply ports for supplying air to the air bag . The viscous material applicator according to claim 1, wherein the air bag is a space formed between a sheet-like diaphragm and an inner wall of the pressurizing chamber . Viscous material application device according to any one of claims 1, wherein 6 to have a plurality of air bags in the pressure chamber. Supplying the viscous material from the viscous material supply means to the pressurizing chamber,
After allowed to fill the viscous material into the pressure chamber, to adjust the air volume of the air bag in the pressurizing chamber based on a pressure of the viscous material of the pressure chamber,
Thereafter, the viscous material application method characterized by discharging the viscous material from the discharge port of the pressure chamber. After application of the viscous material from the pressurizing chamber to the object to be coated, the pressure of the pressurizing chamber and a negative pressure, the pressurizing chamber is increased while relatively moving in a horizontal direction with respect to the object to be coated, the ejection The viscous material application method according to claim 8 , wherein the viscous material remaining at the outlet is sucked into the pressurizing chamber. Viscous material application method according to claim 8 or 9, wherein the pressure to reduce the air quantity of the air bag is -0.2~0.3kgf / cm ^2. Comparing the pressure in the pressure chamber when the viscous material is being discharged from the discharge port and the pressure in the pressure chamber when the viscous material is not being discharged from the discharge port;
The viscous material application method according to claim 8, wherein an air amount of the air bag is adjusted based on the comparison result.

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