JP2016016613A - Cleaning device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cleaning device easy in adjusting a coating quantity of a solvent.SOLUTION: A cleaning device is provided in a screen printer for wiping and cleaning an undersurface of a mask by cleaning paper 13, to which a solvent is applied, and comprises a nozzle 31 for discharging the solvent to the cleaning paper 13, a solvent tank 32 for storing the solvent supplied to the nozzle 31 and connected via supply pipes 351, 352 and 353 piped between the nozzle 31 and itself, a secondary tank 34 connected to the supply pipes between the solvent tank 32 and the nozzle 31 and installed in a higher position than the nozzle 31, a pump 33 connected to the supply pipes between the solvent tank 32 and the secondary tank 34 and pumping up the solvent in the solvent tank 32 to the secondary tank 34 and an opening-closing valve 36 connected to the supply pipes between the secondary tank 34 and the nozzle 31.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a cleaning device mounted on a screen printing machine.

  In a screen printing machine, cream solder is printed on a circuit board through a printing pattern (pattern hole) formed in a mask. At that time, since the cream solder is spread from the upper surface to the mask, the solder wraps around the lower surface of the mask through the pattern holes and becomes dirty. And this stain | pollution | contamination causes a defect by adhering to a circuit board at the time of printing. Therefore, the screen printer is equipped with a cleaning device that removes dirt. Patent Document 1 below discloses an example of such a cleaning device.

  The cleaning device disclosed in the publication is configured to wipe the dirt by sliding the cleaning paper against the lower surface of the mask and then sliding it. At that time, a cleaning solvent is ejected from the nozzle and applied to the cleaning paper. The cleaning device is provided with a solvent supply unit for this purpose. In the solvent supply unit, the solvent stored in the solvent tank is pumped up by the pump, and the solvent is dropped from the nozzle located above onto the cleaning paper.

JP 2007-1225846 A

  In the pump-up type cleaning device, the amount of solvent applied to the cleaning paper is adjusted by adjusting the pressure with a valve provided in the pump. That is, the amount of solvent applied at one time is adjusted and pumped up and discharged from the nozzle. For this reason, even if the amount applied to the cleaning paper is very small (several cc), it takes time to pump up while adjusting the volume. Further, high accuracy is required for adjusting the amount of solvent to be applied, but this is difficult only by driving control of the pump. Therefore, in order to apply an accurate amount of solvent, a plurality of devices such as a throttle valve and a pump operating pressure adjusting valve are required, and the configuration and control become complicated. And there still remains a problem that it takes time to pump up the amount of application.

  Accordingly, an object of the present invention is to provide a cleaning device that can easily adjust the coating amount of a solvent in order to solve such a problem.

  A cleaning device according to the present invention is provided in a screen printing machine for printing cream solder on a circuit board using a mask on which a printing pattern composed of a plurality of through holes is formed, and a solvent is applied to the lower surface of the mask. A cleaning paper wipes and cleans, and a nozzle that discharges the solvent to the cleaning paper and a solvent that is supplied to the nozzle are accommodated and connected via a supply pipe that is connected between the nozzle and the nozzle. A solvent tank; a secondary tank connected to the supply pipe between the solvent tank and the nozzle and installed at a position higher than the nozzle; and the supply pipe between the solvent tank and the secondary tank A pump for pumping the solvent in the solvent tank to the secondary tank, and the supply pipe between the secondary tank and the nozzle And a connection has been opened and closed valves.

  According to the cleaning device of the present invention, when the solvent is previously pumped from the solvent tank containing the solvent to the secondary tank by the pump, and the solvent is applied to the cleaning paper, the on / off valve is opened, so that Since the solvent sent from the next tank to the nozzle is discharged in a substantially constant state, the amount of solvent applied to the cleaning paper can be easily adjusted.

It is sectional drawing which showed the wiping off part of the cleaning apparatus. It is the perspective view which showed the moving mechanism of the cleaning apparatus. It is the conceptual diagram which showed the solvent supply part of the cleaning apparatus. It is the perspective view which showed concretely the solvent supply part of the cleaning apparatus. It is the front view which showed the screen printing machine carrying a cleaning apparatus. It is the figure which showed the insertion port part of the solvent tank at the time of mounting | wearing.

  Next, an embodiment of a cleaning device according to the present invention will be described below with reference to the drawings. The cleaning device of this embodiment is mounted on a screen printing machine. The screen printer performs screen printing of cream solder on the circuit board. For example, board production combining an inspection machine that inspects the printing state and a component mounting machine that mounts electronic components on the circuit board. It constitutes part of the line. The board production line is also provided with a transport device for transporting the circuit board through the insides of the screen printing machine, the inspection machine, and the component mounting machine.

  In the screen printing machine, a mask is installed in the machine, and a circuit board is conveyed by a conveying device below the mask. The screen printing machine includes a substrate holding device for holding and positioning the conveyed circuit board at a printing location, a mask holding device for positioning and holding the mask, and an upper surface with respect to the mask. A squeegee device is provided for spreading cream solder. Furthermore, a cleaning device is also provided for wiping off the dirt on the mask from the lower surface side with a cleaning paper coated with a solvent.

  Here, FIG. 1 is a sectional view showing a wiping portion of the cleaning device. The wiping portion is configured such that cleaning paper before use for wiping is unwound from the first roller, and the used portion is wound by the second roller. The first roller 11 and the second roller 12 are rotatably supported in parallel, and the cleaning paper 13 is wound over both. The first and second rollers 11 and 12 are rotated by a servo motor (not shown) so that tension and slack are applied to the cleaning paper 13 at a transition portion 15 between the rollers 11 and 12.

  A mechanism for pressing the cleaning paper 13 against the lower surface of the mask is provided at the transition portion 15 between the first and second rolls 11 and 12. Each of the first and second rollers 11 and 12 has a rotating shaft in a direction penetrating the drawing, and a pressing member 16 having a size corresponding to the length of the cleaning paper viewed in the rotating shaft direction is disposed. The pressing member 16 made of a foam material can be moved up and down by an air cylinder 17, and a suction port 161 is formed over the entire length, and suction of solder remaining in the mask pattern hole and excess solvent due to negative pressure. It has a configuration that can.

  The solvent discharged from the upper nozzle is applied to the wiping portion over a predetermined range of the cleaning paper 13. That is, the application of the solvent to the cleaning paper 13 is performed by moving the nozzle along the rotation axis direction of the first and second rolls 11 and 12 on the transition portion 15. At this time, in order not to waste the solvent, it is performed in a range corresponding to the print pattern, not the entire mask. Therefore, the cleaning device is provided with a moving mechanism capable of moving the nozzle within a predetermined range. FIG. 2 is a perspective view showing the moving mechanism.

  First, it has a traveling platform 21 on which a nozzle 31 is mounted, and the traveling platform 21 is movable in a linear direction (a direction parallel to the rotation axes of the first and second rolls 11 and 12) by a linear motion guide. It is attached. In the linear motion guide, a guide rail 23 is horizontally fixed to a side surface of an upstanding support plate 22, and a guide block 24 slidable with respect to the guide rail 23 is fitted. The traveling platform 21 is formed integrally with the guide block 24 and can move linearly along the guide rail 23. On the other hand, a servo motor 25 is fixed to the support plate 22, and a rotating belt 26 is stretched around a pulley fixed to the rotating shaft. Further, the rotating belt 26 is also looped over other pulleys 271 and 272 attached to the support plate 22 and a tension roller 275.

  The traveling platform 21 is connected to a linear portion 261 of the rotating belt 26 formed between the pulleys 271 and 272 and linearly moves so as to be pulled by the rotating rotating belt 26. The traveling platform 21 is equipped with a nozzle 31 for discharging the solvent to the cleaning paper, and an on-off valve 36 for controlling the discharge from the nozzle 31 is connected to the nozzle 31. In addition, a supply tube for supplying a solvent is connected to the nozzle 31 via an on-off valve 36. A cable guide 28 that is deformed following the movement is connected to the traveling base 21 so that such supply tubes and cables are not entangled.

  Next, when a solvent is applied to the cleaning paper 13, it is necessary to adjust the solvent discharge amount in accordance with the application range. This is because when the discharge amount is large, the solvent remains in the mask, and when the discharge amount is small, the problem that the dirt cannot be removed properly occurs. Also, the amount of solvent to be applied needs to be finely adjusted depending on the type of solvent. Therefore, in the cleaning device, it is important to discharge an appropriate amount of the set solvent. However, in the conventional pumping type, as described above, the solvent necessary for one application is accurately pumped and discharged from the nozzle in appropriate amounts. It was difficult to make.

  Thus, for example, another conventional example employs a system in which a solvent tank is disposed above and a solvent is discharged from a nozzle by water head pressure. In such an apparatus, an opening / closing valve is provided between the solvent tank and the nozzle, and the amount of the solvent applied to the cleaning paper can be adjusted by controlling the opening / closing thereof. However, if the amount of the solvent in the solvent tank changes, the water head pressure changes and the discharge amount from the nozzle is not stable. Therefore, it is still difficult to adjust the delicate amount. Therefore, the cleaning apparatus of this embodiment has a solvent supply unit configured as follows in order to easily adjust the amount of solvent applied to the cleaning paper.

  FIG. 3 is a conceptual diagram showing the solvent supply unit constituting the cleaning device of the present embodiment. The cleaning device can move the nozzle 31 as described above, and is normally disposed at a retracted position indicated by a solid line, moves in the direction indicated by an arrow during cleaning, and is solvent-free with respect to the lower cleaning paper 13 within a predetermined range. Is discharged. In the present embodiment, the solvent from the solvent tank 32 is not sent directly to the nozzle 31 but is sent in two stages via another small tank.

  That is, the solvent tank 32 is arranged in the lower part of the screen printing machine, and the solvent is pumped up by the pump 33 to the nozzle 31 located above, but the solvent is once supplied to the secondary tank 34 at a position higher than the nozzle 31. From there, it is sent to the nozzle 31. Therefore, the solvent tank 32 is connected to the pump 33 by the supply tube 351, and the secondary tank 34 is connected to the pump 33 by the supply tube 352. The secondary tank 34 and the nozzle 31 are connected by a supply tube 353. The supply tube 353 is a flexible tube that deforms in accordance with the movement of the nozzle 31.

  The secondary tank 34 is a small container as long as it contains at least an amount of solvent used for one application. That is, any container having a size that can accommodate several cc of solvent may be used. Since the secondary tank 34 is located higher than the nozzle 31 and has a very small capacity, the water head height H and the accompanying water head pressure are always substantially constant. The discharge amount per unit time is also almost constant.

  The nozzle 31 is formed integrally with the opening / closing valve 36 so that the solvent from the secondary tank 34 can be discharged by opening / closing the opening / closing valve 36. This on-off valve 36 is a solenoid valve, and is opened and closed by power ON / OFF control. The on-off valve 36 is electrically connected to a control device (not shown) together with the servo motor 25 of the moving mechanism shown in FIG. 2, so that the moving position of the nozzle 31 and the timing of solvent discharge can be controlled. Yes.

  Each time the solvent is discharged from the nozzle 31, the pump 33 is activated in the secondary tank 34, and the solvent is pumped up from the solvent tank 32. Here, a solvent confirmation sensor 37 for confirming the presence or absence of a solvent is provided in the secondary tank 34, and the solvent confirmation sensor 37 is connected to a control device (not shown). Accordingly, the presence / absence of the solvent is confirmed by the detection signal from the solvent confirmation sensor 37, and when it is determined that there is no solvent, the pump 33 operates to pump the solvent to the secondary tank 34.

  By the way, when a failure occurs in the pump 33 or the on-off valve 36, the secondary tank 34 continues to have no solvent. Since such a situation can be confirmed by a detection signal from the solvent confirmation sensor 37, when it is confirmed that there is no solvent for a certain period of time, an error is displayed on a monitor (not shown) installed in the screen printing machine. A notification method such as the above is adopted.

  Further, when the on-off valve 36 breaks down, the solvent leaks from the nozzle 31, so a receiving container 38 that receives the solvent is provided at the retreat position of the nozzle 31. A solvent tank 32 is connected to the receiving container 38 via a collection tube 41 so that the solvent returns to the solvent tank 32. In addition, since the secondary tank 34 is small, the solvent may be fed beyond its capacity. Therefore, an air vent tube 42 is connected to the secondary tank 34, and the other end is connected to the solvent tank 32. The air vent tube 42 opens the secondary tank 34 to the atmosphere on the solvent tank 32 side, and returns excess solvent that has exceeded the allowable amount of the secondary tank 34 to the solvent tank 32.

  More specifically, the solvent supply unit of such a cleaning apparatus is configured as shown in FIG. FIG. 4 is a perspective view specifically showing the solvent supply unit of the cleaning device, which is shown from the opposite side of the support plate 22 shown in FIG. The same components as those shown in FIG.

  The nozzle 31 and the on-off valve 36 are mounted on the traveling platform 21 and are attached so as to be movable in the linear direction by the linear motion guide as described above. On the other hand, the secondary tank 34 is attached to the support bracket 45. The secondary tank 34 is a translucent tube and is a tube member having a diameter of about 15 mm, although it is thicker than the supply tube 351 and the like. In this embodiment, a commercially available tube that is easily available is used in order to obtain an inexpensive configuration.

  An optical solvent confirmation sensor 37 is attached to the secondary tank 34 composed of a translucent tube so that it can be confirmed whether or not a predetermined amount of solvent is contained therein. The solvent confirmation sensor 37 is attached to the secondary tank 34 in accordance with a position where the capacity for one time can be detected because it is sufficient that the amount of solvent to be applied to the cleaning paper can be discharged from the nozzle 31.

  A supply tube 353 is connected to the lower joint 46 in the secondary tank 34, and the supply tube 353 extends to the traveling platform 21 via the cable guide 28 (see FIG. 2). A nozzle 31 integral with the opening / closing valve 36 is mounted on the traveling platform 21, and a supply tube 353 is connected to the opening / closing valve 36. The solvent tank 32 is at a position lower than the positions of the nozzle 31 and the secondary tank 34. Specifically, as shown in FIG. 5, it is installed on the lower front portion of the screen printer 1. FIG. 5 is a front view showing the screen printing machine 1.

  Each device constituting the screen printing machine 1 is incorporated in the inside of the printing machine main body 2, but the solvent tank 32 is inserted into a recessed space 202 formed by cutting out the cover 201 so as to be easily attached and detached. . The solvent tank 32 is a translucent container, in which a float 320 floating in the solvent is placed so that the internal capacity can be seen visually. In addition to the supply tube 351 extending from the inside of the machine, the distal end portions of the collection tube 41 and the air vent tube 42 protrude from above into the recessed space 202. The solvent tank 32 has a bottle shape having an insertion port 321 opened upward, and the tip portions of the three tubes 351, 41, and 42 are inserted as shown in FIG. Here, FIG. 6 is a view showing a portion of the insertion port 321 of the solvent tank 32 at the time of mounting.

  In order to remove the solvent tank 32 from the recessed space 202, the three tubes 351, 41, and 42 must be relatively removed from the solvent tank 32. At that time, the solvent tank 32 is taken out from the recessed space 202 so that the bottom side is pulled out toward the front and lower side. The tubes 351, 41, and 42 made of fluororesin are bent to some extent due to elasticity, but if they are not taken out properly, they may be bent and the solvent may be clogged there. Therefore, as shown in FIG. 6, measures for preventing bending are taken.

  The three tubes 351, 41, and 42 are positioned so as to be bundled by a collecting pipe 47, and a protective pipe 48 is integrally attached to the collecting pipe 47 by a band 49. The protective tube 48 has a length corresponding to the length of the collection tube 41 and the air bleeding tube 42 protruding into the recessed space 202, and the tip 481 is inclined forward according to the take-out posture of the solvent tank 32. It is cut diagonally. The protective tube 48 guides the movement of the insertion port 321 when the solvent tank 32 is taken out, and prevents the tube 351, 41, 42 from being subjected to excessive force, so that the tube 351, 41, 42 is bent. I am trying not to do it.

  Returning to FIG. 4, the supply tube 351 is connected to the pump 33, and the supply tube 352 extends upward from the pump 33 and is connected to the upper joint 51 of the secondary tank 34. An air vent tube 42 is also connected to the upper joint 51, and the air vent tube 42 extends downward and is connected to the solvent tank 32. Further, the collection tube 41 is connected to the receiving container 38 disposed below the nozzle 31 through a bottom through hole. The recovery tube 41 extends downward and is connected to the solvent tank 32.

  In the cleaning device of the present embodiment described above, the mask cleaning operation is performed as follows. In the screen printing machine 1, the lower surface of the mask becomes dirty or the solder remains in the pattern holes due to repeated printing, and the printing quality deteriorates. Therefore, the mask is periodically cleaned by the cleaning device. At that time, in the wiping portion shown in FIG. 1, the pressing member 16 is raised by the air cylinder 17, and the cleaning paper 13 of the transition portion 15 is pressed against the lower surface of the mask. In this state, the wiping portion is moved by a moving mechanism such as a ball screw, and the dirt on the mask is wiped off by the cleaning paper 13.

  In such a wiping operation, a solvent is applied to the cleaning paper 13. That is, the solvent is discharged from the nozzle 31 while the traveling platform 21 moves, and the solvent is applied to a predetermined range of the cleaning paper 13. For this purpose, the rotation is transmitted to the rotating belt 26 by the rotation control of the servo motor 25 shown in FIG. 2, and the guide block 24 slides on the guide rail 23 to form the linear motion of the carriage 21. The opening / closing control of the opening / closing valve 36 is performed in accordance with the movement of the traveling platform 21.

  When the on-off valve 36 is opened, the solvent stored in the secondary tank 34 is sent to the nozzle 31 by the water head pressure and discharged. By discharging the solvent in accordance with the movement of the nozzle 31, the solvent is applied to a predetermined range of the cleaning paper 13. At this time, since the amount of the solvent impregnated in the cleaning paper 13 is determined, in this embodiment, the moving speed of the nozzle 31 (running platform 21) and the opening / closing cycle of the opening / closing valve 36 are controlled with respect to such application adjustment. .

  When the solvent is discharged from the nozzle 31, the solvent in the secondary tank 34 runs out, so that the pump 33 is driven and controlled according to the detection signal of the solvent confirmation sensor 37 that detects the state, and a predetermined amount of water is supplied from the solvent tank 32. The solvent is pumped up. In this case, the amount of solvent used for approximately one application is pumped up. However, since the capacity of the secondary tank 34 is small, the capacity of the secondary tank 34 is exceeded when it exceeds the capacity, or when the pump 33 is pumped up beyond the set amount due to a malfunction of the pump 33. The solvent is returned to the solvent tank 32 through the air vent tube 42.

  Further, when a failure occurs in the on-off valve 36 for some reason, the solvent leaks from the nozzle 31, but the solvent is returned from the receiving container 38 to the solvent tank 32 through the recovery tube 41. At this time, since the solvent does not accumulate in the secondary tank 34, pumping control of the pump 33 is continued by the detection signal from the solvent confirmation sensor 37. In such a case, it is determined that there is an abnormality based on the detection signal from the solvent confirmation sensor 37, and this is indicated as an alarm display on a monitor or the like. In addition, a failure of the pump 33 may be a cause that the solvent does not accumulate in the secondary tank 34.

  According to the cleaning apparatus of the present embodiment described above, the solvent is pumped in advance in the secondary tank 34 and the solvent is discharged by the hydraulic head pressure between the nozzle 31 and the cleaning paper 13 as compared with the conventional example. Easy to adjust the coating. That is, various devices such as a throttle valve and a pressure control valve and their control are no longer necessary, and the solvent supply to the secondary tank 34 may be simple pumping. And the amount of the solvent discharged by the substantially constant water head pressure is also constant. Therefore, highly accurate application adjustment can be performed only by two controls of the moving speed of the carriage 21 and the opening / closing cycle of the opening / closing valve 36.

  The nozzle 31 is configured integrally with the on-off valve 36, and the solvent is always sent to just before the nozzle 31. Therefore, it takes no time to prepare for discharge, and the application to the cleaning paper 13 can be completed in a short time, and the productivity can be improved. Further, by providing the solvent confirmation sensor 37, it is possible to confirm the malfunction of the pump 33 and the on-off valve 36. Even when the on-off valve 36 breaks down, the solvent is received by the receiving container 38 and returned to the solvent tank 32, so that it is possible to avoid the electrical equipment in the machine from being damaged or soiled by the leaked solvent. Further, since the secondary tank 34 has a very small capacity, the installation space in the machine can be reduced.

  The solvent tank 32 is arrange | positioned under the front part of the screen printing machine, as shown in FIG. In particular, it is easy to check the remaining amount of the solvent because it is placed in the recessed space 202 on the front surface of the machine body and visible from the outside. Further, the solvent can be replenished without opening and closing the cover 201, and the handling thereof is easy. At this time, since the solvent tank 32 is taken in and out in the narrow concave space 202, the tubes 41 and 42 may be bent if the operator is not careful. However, the protection tube 48 protects the tubes. Since the solvent discharged from the nozzle 31 is stored in the secondary tank 34, the solvent tank 32 can be replenished even when the screen printing machine is in operation. In other words, solvent replenishment can be performed without stopping production, leading to improved productivity.

  By the way, it is preferable to provide a recovery side sensor for confirming the solvent flowing through the recovery tube 41 connecting the receiving container 38 and the solvent tank 32. This is because the malfunction of the on-off valve 36 can be detected by checking the flow of the solvent with the recovery side sensor in accordance with the opening and closing of the on-off valve 36.

As mentioned above, although embodiment of the components collection | recovery apparatus of this invention was described, this invention is not limited to this, A various change is possible in the range which does not deviate from the meaning.
For example, in the above embodiment, the pump 33 is driven according to the detection signal from the solvent confirmation sensor 37 to supply the solvent to the secondary tank 34. However, the pump 33 is driven according to the opening / closing of the on-off valve 36. Also good.
Further, for example, in the above embodiment, the solvent tank 31 is disposed below, but may be disposed above.
Further, as in the above-described embodiment, the secondary tank 34 is not limited to a semi-transparent tube, and the solvent confirmation sensor 37 is not limited to an optical sensor. It may be a batch or more.

DESCRIPTION OF SYMBOLS 1 ... Screen printer 13 ... Cleaning paper 21 ... Running stand 31 ... Nozzle 32 ... Solvent tank 33 ... Pump 34 ... Secondary tank 36 ... On-off valve 37 ... Solvent confirmation sensor 41 ... Recovery tube 42 ... Air vent tube 351,352 353 ... Supply tube

Claims (8)

A cleaning device provided in a screen printing machine for printing cream solder on a circuit board using a mask on which a printed pattern comprising a plurality of through holes is formed, and wiping and cleaning the lower surface of the mask with a cleaning paper coated with a solvent In
A nozzle for discharging a solvent to the cleaning paper;
A solvent tank that contains a solvent to be supplied to the nozzle and connected via a supply pipe that is piped between the nozzle and the nozzle;
A secondary tank connected to the supply pipe between the solvent tank and the nozzle and installed at a position higher than the nozzle;
A pump connected to the supply pipe between the solvent tank and the secondary tank and pumping up the solvent in the solvent tank to the secondary tank;
A cleaning device comprising an on-off valve connected to the supply pipe between the secondary tank and the nozzle.   The cleaning apparatus according to claim 1, further comprising a solvent confirmation sensor for confirming an amount of the solvent accommodated in the secondary tank.   The cleaning apparatus according to claim 2, wherein the solvent confirmation sensor is configured to confirm that at least one volume of solvent to be applied from the nozzle to the cleaning paper is contained.   The cleaning device according to claim 1, wherein the secondary tank is a pipe member that is thicker than the supply pipe.   The cleaning device according to claim 4, wherein the secondary tank is a transparent or translucent tube, and the solvent confirmation sensor is an optical sensor attached to the translucent tube.   The cleaning apparatus according to claim 1, further comprising an air vent pipe connecting the secondary tank and the solvent tank.   The nozzle is capable of moving within a predetermined application range with respect to the cleaning paper from a retracted position by a driving means, and a solvent receiver is installed at the retracted position, and a recovery unit that connects the solvent receiver and the solvent tank. The cleaning apparatus according to claim 1, further comprising a tube. The cleaning apparatus according to claim 7, further comprising a recovery side sensor for confirming the solvent passing through the recovery pipe.

Images