JP5126118B2 - Screen printing apparatus and screen printing method - Google Patents

Description

  The present invention relates to a screen printing apparatus and a screen printing method for printing paste such as cream solder or conductive paste on a substrate.

  In an electronic component mounting process, screen printing is used as a method for printing paste such as cream solder or conductive paste on a substrate. In this method, a mask plate provided with a pattern hole according to a printing target part is brought into contact with the substrate, a paste is supplied onto the mask plate, and a squeegee is slid on the substrate through the pattern hole. The paste is printed.

  During the printing operation, cream solder that protrudes from the printed area on the substrate adheres to the lower surface of the mask plate, or cream solder that has not been completely transferred onto the substrate remains in the opening of the mask plate. Pollution occurs. Such contamination by cream solder hinders normal printing on the subsequent substrate, and therefore it is necessary to perform cleaning to remove these cream solders.

For this reason, conventionally, a screen printing apparatus having a cleaning mechanism for removing residual cream solder by wiping the mask plate from the lower surface side using a dedicated cleaning paper is known (for example, see Patent Document 1). In this cleaning mechanism, the cleaning paper drawn from the paper roll is pressed against the lower surface of the mask plate by the cleaning head, and then the cleaning head is moved horizontally, whereby the lower surface of the mask plate is wiped by the cleaning paper. . In the example shown here, both sides of the cleaning paper are used in order to effectively use the cleaning paper.
JP 2005-199452 A

  However, in the prior art in which the cleaning is performed by pressing the cleaning paper against the mask plate as described above, there are the following problems due to the method. That is, since the cleaning paper is supplied while being wound around the paper roll, it is necessary to replace the paper roll every time a predetermined amount of cleaning paper supplied by one paper roll is used up. For this reason, in the process of continuing the screen printing operation continuously, it is necessary to stop the apparatus at a predetermined frequency in order to replace the paper roll, which is one factor that causes a decrease in productivity. Further, since the cleaning paper is disposable, it is difficult to reduce the running cost, and at the same time, waste of resources is generated.

  Therefore, an object of the present invention is to provide a screen printing apparatus and a screen printing method capable of realizing reduction in running cost and improvement in productivity.

The screen printing apparatus of the present invention is a screen printing for printing a paste on a substrate through the pattern hole by bringing the substrate into contact with a mask plate provided with a pattern hole and sliding a squeegee on the mask plate. And a cleaning mechanism for cleaning the mask plate by pressing a sliding medium formed of a porous material into a sheet shape against the lower surface of the mask plate by a cleaning head and sliding the screen. The cleaning mechanism includes a cleaning medium circulation unit that moves the cleaning medium along a predetermined circulation path and supplies the cleaning medium to the cleaning head, and a cleaning mechanism that is disposed in the circulation path and adheres to the cleaning medium by the cleaning. Exclude object A medium cleaning unit to a head lifting mechanism for raising and lowering the cleaning head, the cleaning head, the head elevating mechanism, and a cleaning head moving means for horizontally moving integrally with said cleaning medium circulation means and the medium cleaning unit The medium cleaning unit is configured to blow / blow off a gas from a surface opposite to a cleaning surface on which the cleaning object adheres to the cleaning medium, thereby separating / removing the cleaning object from the cleaning medium. And suction means for separating and removing the cleaning object from the cleaning medium by sucking the cleaning medium from the cleaning surface side to which the cleaning object adheres, and capturing the separated and removed cleaning object. Collect and collect And a recovery means.

The screen printing method of the present invention includes a screen printing unit for bringing a substrate into contact with a mask plate provided with pattern holes and sliding a squeegee on the mask plate, and a cleaning medium in which a porous material is formed into a sheet shape. A cleaning mechanism that cleans the mask plate by wiping it against the lower surface of the mask plate by a cleaning head, and the cleaning mechanism moves the cleaning medium along a predetermined circulation path to the cleaning head. A cleaning medium circulation means for feeding to the medium, a medium cleaning unit that is disposed in the circulation path and removes an object to be cleaned attached to the cleaning medium by the cleaning, a head lifting mechanism that lifts and lowers the cleaning head, Cleanin The head, the head elevating mechanism, wherein a cleaning head moving means for horizontally moving integrally with the cleaning medium circulation means and the medium cleaning unit, the medium cleaning unit, the cleaning object to the cleaning medium Blowing means for separating and removing the cleaning object from the cleaning medium by blowing gas from the surface opposite to the cleaning surface to which the cleaning object adheres, and the cleaning medium from the cleaning surface side to which the cleaning object adheres By the screen printing apparatus having a configuration including a suction unit that separates and removes the cleaning object from the cleaning medium, and a collection unit that collects and collects the separated and removed cleaning object , Page to the substrate through the pattern hole A screen printing method for printing a paste, a printing step for executing a printing operation for printing a paste on the substrate by the screen printing unit, and raising the cleaning head after the printing execution step is finished to perform the cleaning With the medium pressed against the lower surface of the mask plate, the cleaning head moves horizontally to clean the lower surface of the mask plate, and the cleaning medium moves along a predetermined circulation path to move the cleaning head. And a medium cleaning step of removing a cleaning object adhered to the cleaning medium by the medium cleaning unit while feeding to the medium.

  According to the present invention, in the cleaning mechanism that cleans the mask plate by pressing the cleaning medium formed of the porous material into a sheet shape against the lower surface of the mask plate by the cleaning head and wiping it off, the cleaning medium is predetermined with respect to the cleaning head. It is necessary to stop the apparatus by providing a cleaning medium circulating means for feeding and collecting through the circulation path and a medium cleaning section that is disposed in the circulation path and removes a cleaning object attached or impregnated with the cleaning medium. Instead, the cleaning medium can be repeatedly reused to reduce running costs and improve productivity.

  Next, embodiments of the present invention will be described with reference to the drawings. 1 is a front view of a screen printing apparatus according to an embodiment of the present invention, FIG. 2 is a side view of the screen printing apparatus according to an embodiment of the present invention, and FIG. 3 is a screen printing apparatus according to an embodiment of the present invention. FIG. 4 is an explanatory view of the configuration of the cleaning unit in the screen printing apparatus according to the embodiment of the present invention. FIG. 5 is a medium cleaning unit provided in the cleaning unit of the screen printing apparatus according to the embodiment of the present invention. FIG. 6 is a structural explanatory diagram of a liquid circulation unit used in the medium cleaning unit of the screen printing apparatus according to the embodiment of the present invention, and FIG. 7 is a diagram of the screen printing apparatus according to the embodiment of the present invention. FIG. 8 is an operation explanatory view showing a screen printing method according to an embodiment of the present invention.

First, the structure of the screen printing apparatus will be described with reference to FIG. 1, FIG. 2, and FIG. In FIG. 1, the screen printing apparatus is configured by disposing a screen printing unit 10 above a substrate positioning unit 1. The substrate positioning unit 1 is configured by stacking a Y-axis table 2, an X-axis table 3, and a θ-axis table 4, and further placing a Z-axis table 5 thereon. On the Z-axis table 5, there is provided a substrate holder 6 that receives and holds the substrate 8 from the lower surface side. The substrate 8 carried in from the upstream side via the carry-in conveyor 9A (FIG. 2) is carried onto the substrate holding unit 6 by the printing conveyor 9, and is sandwiched from both sides by the clamper 7 to fix the position. The substrate 8 after being printed by the screen printing unit 10 described below is carried out to the downstream side via the carry-out conveyor 9B (see FIG. 2).

  A screen printing unit 10 disposed above the substrate positioning unit 1 includes a mask plate 12 extended on a mask frame 11. The mask plate 12 is provided with a pattern hole 12a (see FIG. 3) corresponding to a printing target. As shown in FIG. 2, two bar-shaped brackets 22 are horizontally extended on the side surfaces of the vertical frame 21 provided on both sides of the substrate positioning portion 1. On the upper surfaces of the two brackets 22, an L-shaped cross-sectional mask holder 23 is installed in the Y direction. The mask holder 23 positions and holds the mask frame 11 of the mask plate 12.

  A squeegee head 13 is disposed on the mask plate 12. The squeegee head 13 has a structure in which a squeegee raising / lowering mechanism 14 for raising and lowering the squeegee 15 is disposed on a horizontal plate 13a. As shown in FIG. 2, both ends of the plate 13a are guides arranged on a vertical frame 21. The mechanism is supported so as to be slidable in the Y direction. The plate 13a is horizontally moved in the Y direction by squeegee moving means including a nut 16a, a feed screw 16b, and a rotary drive motor (not shown). Further, by driving the squeegee raising / lowering mechanism 14, the squeegee 15 moves up and down and comes into contact with the upper surface of the mask plate 12.

  The squeegee is moved on the mask plate 12 supplied with the cream solder 25 (see FIG. 8A) as a paste in a state where the Z-axis table 5 is raised and the lower surface of the mask plate 12 is brought into contact with the substrate 8. By driving the means and moving the squeegee 15 in the Y direction, the cream solder 25 is printed on the substrate 8 through the pattern holes 12a. That is, the screen printing unit 10 causes the substrate 8 to come into contact with the mask plate 12 provided with the pattern holes 12a, and slides the squeegee 15 on the mask plate 12 to paste the substrate 8 through the pattern holes 12a with the paste. Printing a certain cream solder 25,

  A camera 19 is provided above the screen printing unit 10. As shown in FIG. 3, the camera 19 is horizontally moved in the XY directions by the X-axis table 18 and the Y-axis table 17. The X-axis table 18 and the Y-axis table 17 serve as a camera moving mechanism that moves the camera 19. By moving the camera 19 with respect to the mask plate 12 by the camera moving mechanism, the camera 19 images an arbitrary position of the mask plate 12. The substrate positioning unit 1 is moved in the Y direction from below the screen printing unit 10 by the Y-axis table 2 so that the held substrate 8 can be moved to the substrate recognition position. In this state, the camera 19 is moved. By moving to the substrate 8 on the substrate positioning unit 1, an arbitrary position of the substrate 8 can be imaged by the camera 19 and the substrate position can be recognized.

A cleaning unit 20 (cleaning mechanism) is disposed on the side of the substrate positioning unit 1 on the Y-axis table 2. The cleaning unit 20 has a configuration in which each element described below is built in the main body 20a, and the cleaning head 24 protrudes from the upper part of the main body 20a. By driving the Y-axis table 2, the cleaning unit 20 moves in the Y direction together with the substrate positioning unit 1, and the lower surface of the mask plate 12 is cleaned by the cleaning head 24. In the present embodiment, the cleaning unit 20 serving as a cleaning mechanism includes a cleaning medium 2 in which a porous material is formed into a sheet shape.
The mask plate 12 is cleaned by pressing 6 (see FIG. 4) against the lower surface of the mask plate 12 by the cleaning head 24 and sliding it.

  The configuration of the cleaning unit 20 will be described with reference to FIG. A cleaning head 24 is disposed inside the main body 20 a so as to project a sliding contact surface 24 a provided on the upper surface, and the cleaning head 24 can be raised and lowered by a head lifting mechanism 30. By driving the head elevating mechanism 30, the cleaning head 24 moves up and down (arrow a), so that the slidable contact surface 24a can freely contact and separate from the lower surface 12b of the mask plate 12. Inside the main body 20a, an endless cleaning medium 26 is tuned along a circulation path formed by one drive roller 32 and three guide rollers 34. In this circulation path, the cleaning medium 26 circulates along the sliding contact surface 24 a of the cleaning head 24.

  The drive roller 32 is driven to rotate by a motor 31 and the cleaning medium 26 is driven in a predetermined moving direction (by moving the cleaning medium 26 between the pair of adjacent pinch rollers 33). Here, it is sent in the direction of arrow b). As a result, the cleaning medium 26 moves along the circulation path described above and is fed to the sliding contact surface 24 a of the cleaning head 24. Accordingly, the motor 31, the driving roller 32, the pinch roller 33, and the guide roller 34 move the cleaning medium 26 that is a cleaning medium along a predetermined circulation path and feed the cleaning medium 24 to the cleaning head 24. Configure.

  The cleaning medium 26 will be described. The cleaning medium 26 is manufactured by molding a porous material into a sheet shape, and has a function of wiping the cleaning object attached to the lower surface 12 b by slidingly contacting the lower surface 12 b of the mask plate 12. Examples of the porous material used here include felt-like cloth and paper, as well as a soft resin having a fine hole inside. In short, any material can be used as long as it has the property of being able to be impregnated with a cleaning object such as cream solder, which is a viscous material, and can be wiped off.

  By driving the head elevating mechanism 30 to raise the cleaning head 24, the cleaning medium 26 that has circulated around the sliding contact surface 24a is pushed up, and the cleaning surface 26a contacts the lower surface 12b of the mask plate 12 (FIG. 8B). )reference). In this state, the Y-axis table 2 is driven to horizontally move the entire cleaning unit 20 in the Y direction, whereby the cleaning object 25a adheres to the cleaning surface 26a and is removed from the lower surface 12b, and mask cleaning is executed. The Note that the fluctuation in tension generated in the cleaning medium 26 by pushing up the endless cleaning medium 26 by the cleaning head 24 is adjusted by expansion and contraction of a tension spring 35 provided on one guide roller 34.

  In this mask cleaning, it is necessary to always press the cleaning medium 26 in a clean state against the mask plate 12. In the conventional cleaning mechanism, a disposable cleaning paper is used as a cleaning medium, and new cleaning paper drawn out from a paper roll containing unused cleaning paper is always fed to the cleaning head 24. The method was common. However, in such a conventional method, waste of resources due to disposable cleaning paper and time loss due to stoppage of the apparatus for replacing the paper roll are unavoidable.

In the present embodiment, in order to eliminate such waste and time loss, a cleaning object 25a such as cream solder attached to the cleaning medium 26 is disposed in the circulation path of the cleaning medium 26 as described below. A medium cleaning unit 40 is provided inside the cleaning unit 20 so that the cleaning medium 26 can be circulated and reused by being removed. The cleaning medium 26 fed by the driving roller 32 and guided by the lower right guide roller 34 is introduced into the medium cleaning unit 40 in a posture with the cleaning surface 26a facing the lower surface.

  In the medium cleaning unit 40, the cleaning object 25a adhering from the cleaning surface 26a side is removed from the cleaning medium 26, and the cleaning medium 26 contaminated by the cleaning is cleaned. That is, the medium cleaning unit 40 is disposed in the circulation path of the cleaning medium 26 and removes the cleaning object 25a attached to the cleaning medium 26 by cleaning. In the above-described configuration, the Y-axis table 2 constitutes a cleaning head moving unit that moves the cleaning head 24 horizontally together with the head lifting / lowering unit, the cleaning medium circulating unit, and the medium cleaning unit 40.

  Next, the structure of the medium cleaning unit 40 will be described with reference to FIGS. FIG. 5 shows a cross section of the YZ plane of the cleaning unit 20 shown in FIGS. In FIG. 5, the medium cleaning unit 40 includes a cleaning chamber 41 that cleans the cleaning medium 26. The cleaning chamber 41 is divided into three sections: a first blow tank 41a, a wash tank 41b, and a second blow tank 41c. ing. The first blow tank 41a, the cleaning tank 41b, and the second blow tank 41c are closed by two adjacent ones of four partition walls 41d, 41e, 41f, and 41g provided in order from the introduction side of the cleaning medium 26. Also constitutes a closed compartment.

  The partition walls 41d, 41e, 41f, and 41g are respectively provided with guide members 46 for allowing the cleaning medium 26 to pass therethrough. The used cleaning medium 26 to be cleaned is discharged from the cleaning chamber 41 through the first blow tank 41a, the cleaning tank 41b, and the second blow tank 41c sequentially with the cleaning surface 26a facing downward. (Arrow d).

  A first duct 48a and a second duct 48b are respectively provided below the first blow tank 41a and the second blow tank 41c, and the first duct 48a and the second duct 48b are further passed through a filter base 48c. And communicated with the suction space 48d. The suction space 48d is exhausted by the exhaust mechanism 50, and a filter 49 for capturing solid components such as solder particles in the cleaning object 25a is mounted on the upper surface of the filter base 48c.

  A cleaning liquid 43 for cleaning the cleaning medium 26 is stored inside the cleaning tank 41b, and the cleaning liquid 43 is supplied from a liquid introduction opening 42a provided in the upper part. An ultrasonic oscillator 47 is mounted on the bottom surface of the cleaning tank 41b, and by operating the ultrasonic oscillator 47, ultrasonic vibration is applied to the cleaning liquid 43 in the cleaning tank 41b, thereby causing the cleaning medium 26 to move. Ultrasonic cleaning is performed. The cleaning liquid 43 contaminated by the cleaning is discharged from the liquid discharge opening 42b provided on the bottom surface, and is transferred to the liquid processing section 51 shown in FIG. 6 by the first pump P1.

The cleaning function of the cleaning medium 26 by the medium cleaning unit 40 having the above configuration will be described. The cleaning medium 26 used for cleaning is introduced into the first blow tank 41a from the right side, which is the upstream side in the feed direction (arrow c). A first gas injection nozzle 44 </ b> A is disposed in the first blow tank 41 a, and the first gas injection nozzle 44 </ b> A is connected to a gas supply source 45. By operating the gas supply source 45, gas is blown from the first gas injection nozzle 44A from the upper surface side of the cleaning medium 26, that is, from the opposite side of the cleaning surface 26a to which the cleaning object 25a adheres. As a result, the cleaning object 25a adhering to the cleaning surface 26a is peeled off from the cleaning surface 26a by the gas blowing action (arrow e) and moved downward.

  At this time, since the inside of the suction space 48d is exhausted by the exhaust mechanism 50 (arrow j), the inside of the first blow tank 41a is sucked through the first duct 48a. As a result, the cleaning object 25a separated and removed by the blowing action flows downward in the first duct 48a (arrow f) and is captured and retained on the upper surface of the filter 49. Since these cleaning objects 25a contain reusable solder components, they are appropriately collected.

  That is, the medium cleaning unit 40 shown in the above configuration separates the cleaning object 25a from the cleaning medium 26 by blowing gas from the surface opposite to the cleaning surface 26a to which the cleaning object 25a adheres to the cleaning medium 26. It has a form provided with blowing means (gas supply source 45 and first gas injection nozzle 44A) for removal. Further, the medium cleaning unit 40 sucks the cleaning medium 26 from the side of the cleaning surface 26a to which the cleaning target object 25a adheres, thereby separating / removing the cleaning target object 25a from the cleaning medium 26 (the exhaust mechanism 50 and the first mechanism). 1 duct 48a).

  After the rough removal of the cleaning object 25a is performed in the cleaning tank 41b, the cleaning medium 26 is guided into the cleaning tank 41b containing the cleaning liquid 43, where it is immersed in the cleaning liquid 43 for cleaning. That is, due to the ultrasonic vibration applied from the ultrasonic oscillator 47, the cleaning object 25a attached to or impregnated with the cleaning medium 26 is peeled and removed from the cleaning medium 26, and moves downward in the cleaning liquid 43 (arrow). g). In the process of continuously cleaning the cleaning medium 26 with the cleaning liquid 43, the cleaning liquid 43 in the cleaning tank 41b becomes contaminated. Therefore, in the present embodiment, the cleaning liquid 43 is the liquid processing unit 51 shown in FIG. It is made to circulate between and removes pollution.

  That is, the cleaning liquid 43 including the cleaning object 25a discharged from the liquid discharge opening 42b and transferred by the first pump P1 reaches [1] in FIG. 6 (arrow k), and enters the treatment tank 52 through the liquid introduction pipe 53. Flow down. The processing tank 52 is a cascade-type liquid storage tank that is partitioned into three compartments by two dam portions 52d and 52e having different heights. The cleaning liquid 43 flowing down from the liquid introduction pipe 53 is first stored in the first settling tank 52a, where the cleaning object 25a in the cleaning liquid 43 flowing down from the liquid introduction pipe 53 is precipitated downward by gravity (arrow l). ), Deposited on the bottom of the first sedimentation tank 52a. Since these deposits contain reusable components, they are subject to recovery.

  The supernatant cleaning liquid 43 overflows over the weir 52d into the second sedimentation tank 52b (arrow m), where some cleaning object 25a is further settled. Similarly, the supernatant cleaning solution 43 overflows the weir portion 52e and overflows into the drainage tank 52c (arrow n). Since the cleaning liquid 43 stored in the drainage tank 52c does not substantially contain the cleaning object 25a, the cleaning tank 43b can be used again. The cleaning liquid 43 thus processed is sucked by the second pump P2 through the drain opening 52f and further supplied to the liquid introduction opening 42a shown in FIG. That is, as shown in the above configuration, the medium cleaning unit 40 in the present embodiment includes the cleaning tank 41b that stores the cleaning liquid 43, and the cleaning medium 26 passes through the cleaning tank 41b and is immersed in the cleaning liquid 43. The cleaning object 25a is separated and removed from the cleaning medium 26.

After the cleaning in the cleaning tank 41b is completed, the cleaning medium 26 is guided into the second blow tank 41c, where the cleaning liquid 43 is removed. A second gas injection nozzle 44 </ b> B is disposed in the second blow tank 41 c, and the second gas injection nozzle 44 </ b> B is connected to a gas supply source 45. By operating the gas supply source 45, gas is blown from the second gas injection nozzle 44 </ b> B to the cleaning medium 26. As a result, the cleaning liquid 43 adhering to and impregnating the cleaning medium 26 is removed by the gas blowing action (arrow h) and falls downward as a fine droplet.

  At this time, since the inside of the second duct 48b is exhausted by the exhaust mechanism 50 (arrow j), the inside of the second blow tank 41c is sucked through the first duct 48a. Thereby, the droplet of the cleaning liquid 43 removed by the blowing action flows downward in the second duct 48b (arrow i) and is exhausted by the exhaust mechanism 50. In this way, the cleaning object 25a adhering to the cleaning surface 26a is separated and removed, and the cleaning medium 26 in a state where the droplets of the cleaning liquid 43 are removed is drawn out from the medium cleaning unit 40 and sent to the cleaning head 24. Be paid.

  In the configuration of the medium cleaning unit 40, the cleaning object 25a separated and removed from the cleaning medium 26 stays on the upper surface of the filter 49 attached to the filter base 48c and is captured. Therefore, by removing the filter 49, the cleaning object 25a can be collected and recovered. Furthermore, in the liquid processing unit 51 shown in FIG. 6, the cleaning object 25a that has settled and stayed in the first settling tank 52a can be collected and recovered. That is, in the screen printing apparatus shown in the present embodiment, recovery means (filter base 48c and filter 49, first sedimentation tank 52a) that collects and recovers the cleaning object 25a separated and removed by the medium cleaning unit 40. ).

  In the configuration example shown in FIG. 5, an example in which ultrasonic cleaning is applied as a cleaning method using the cleaning liquid 43 in the cleaning tank 41b is shown, but various other methods are selected as the cleaning method using the cleaning liquid 43. Is possible. For example, as shown in FIG. 7A, in the cleaning tank 41b, liquid jet nozzles 55 are arranged on both sides or one side of the cleaning medium 26, and the cleaning liquid 43 supplied from the cleaning liquid supply source 56 is supplied to the cleaning tank 41b. The cleaning object 25a may be separated and removed from the cleaning medium 26 by spraying the cleaning medium 26 passing through the cleaning medium 26.

  In other words, in this example, the medium cleaning unit 40 includes a cleaning tank 41b having liquid injection means (a liquid injection nozzle 55 and a cleaning liquid supply source 56) for injecting the cleaning liquid 43, and allows the cleaning medium 26 to pass through the cleaning tank 41b. However, the cleaning liquid 43 is ejected onto the cleaning medium 26 by the liquid ejecting means, whereby the cleaning object 25a is separated and removed from the cleaning medium 26. 7 shows an example of submerged spraying in the cleaning liquid 43, the cleaning tank 43b is not filled with the cleaning liquid 43, and the cleaning medium 26 is in the air outside the cleaning liquid 43. The cleaning liquid 43 may be jetted onto the cleaning medium 26 in the existing state.

  Further, in the example shown in FIG. 7B, an example using the brush unit 57 provided with the brush 57a is shown as the simplest configuration. That is, in this case, the brush unit 57 is disposed in the cleaning tank 41b so that the brush 57a contacts the both surfaces or one surface of the cleaning medium 26 passing through the cleaning tank 41b. As the cleaning medium 26 passes through the cleaning tank 41b, the cleaning object 25a attached to both surfaces or one surface of the cleaning medium 26 is scraped off by the brush 57a. Even with such a simple method, the object to be cooled 25a can be separated and removed from the cleaning medium.

Next, a screen printing method by the screen printing apparatus having the above configuration will be described with reference to FIG. FIG. 8A shows a printing process in which the screen printing unit 10 performs a printing operation for printing the cream solder 25 as a paste on the substrate 8. That is, in the substrate positioning unit 1, the substrate 8 held on the lower surface side by the substrate holding unit 6 and sandwiched on both sides by the clamper 7 is brought into contact with the lower surface of the mask plate 12. In this state, the squeegee 15 is slid on the mask plate 12 (arrow p) to print the cream solder 25 as a paste on the substrate 8 through the pattern holes 12a.

  In the process of repeatedly executing this printing process, the mask cleaning process is executed at predetermined intervals. That is, as shown in FIG. 8B, after the printing process is completed, the cleaning unit 20 is moved to the lower surface side of the mask plate 12 and then the cleaning head 24 is raised (arrow q) to It abuts on the lower surface 12b. Then, with the cleaning medium 26 pressed against the lower surface 12b of the mask plate 12, the cleaning head 24 is moved horizontally (arrow r) to clean the lower surface 12b of the mask plate 12.

  In the present embodiment, the cleaning medium 26 that has been soiled by cleaning as described above is circulated and used. Therefore, the cleaning medium 26 is moved along a predetermined circulation path set in the medium cleaning unit 40 to perform cleaning. While being fed to the head 24, a medium cleaning process is performed to remove the cleaning object 25a attached to the cleaning medium 26 by the medium cleaning unit 40. This medium cleaning process may be performed concurrently with the mask cleaning process shown in FIG. 8B, and in the printing process shown in FIG. 8A, the cleaning unit 20 executes the mask cleaning process. It may be executed at the time of waiting for cleaning.

  As described above, the present invention employs a cleaning mechanism that cleans the mask plate 12 by pressing the cleaning medium 26 formed of a porous material into a sheet shape against the lower surface 12b of the mask plate 12 by the cleaning head 24 and wiping it off. doing. In this cleaning mechanism, the cleaning medium circulating means for feeding the cleaning medium 26 to the cleaning head 24 through a predetermined circulation path and collecting the cleaning medium 26, and the cleaning medium disposed in the circulation path and attached or impregnated to the cleaning medium 26 A medium cleaning unit 40 for removing the object 25a is provided.

  As a result, a device stop inevitably occurred in a conventional device using disposable cleaning paper, that is, a device stop for exchanging a roll accompanying the use of a cleaning paper supplied in the form of a paper roll occurs. There is no. Therefore, the same cleaning medium 26 can be reused repeatedly to reduce the running cost and improve the productivity.

  INDUSTRIAL APPLICABILITY The screen printing apparatus and the screen printing method of the present invention have an effect that a running cost can be reduced and productivity can be improved, and screen printing for printing paste such as cream solder or conductive paste on a substrate is effective. Useful in the field.

1 is a front view of a screen printing apparatus according to an embodiment of the present invention. The side view of the screen printing apparatus of one embodiment of this invention The top view of the screen printing apparatus of one embodiment of this invention Structure explanatory drawing of the cleaning unit in the screen printing apparatus of one embodiment of this invention Structure explanatory drawing of the medium cleaning part with which the cleaning unit of the screen printing apparatus of one embodiment of this invention was equipped Structure explanatory drawing of the liquid circulation part used for the medium cleaning part of the screen printing apparatus of one embodiment of this invention The fragmentary sectional view of the media cleaning part of the screen printer of one embodiment of the present invention Operation explanatory diagram showing a screen printing method of one embodiment of the present invention

1 Substrate positioning unit 2 Y-axis table (cleaning head moving means)
8 Substrate 12 Mask plate 12a Pattern hole 15 Squeegee 20 Cleaning unit (cleaning mechanism)
24 Cleaning head 25 Cream solder (paste)
25a object to be cleaned 26 cleaning medium 26a cleaning surface 30 head lifting mechanism 31 motor 32 drive roller 40 medium cleaning unit 41a first blow tank 41b cleaning tank 43 cleaning liquid 44A first gas injection nozzle (blow means)
47 Ultrasonic oscillator 48a First duct 48b Second duct 49 Filter 51 Liquid processing section

Claims (6)

A substrate is brought into contact with a mask plate provided with a pattern hole, and a squeegee is slid on the mask plate, thereby printing a paste on the substrate through the pattern hole, and a sheet of porous material. A screen printing apparatus having a cleaning mechanism for cleaning the mask plate by pressing and sliding the cleaning medium formed into a shape against the lower surface of the mask plate by a cleaning head,
The cleaning mechanism includes a cleaning medium circulation unit that moves the cleaning medium along a predetermined circulation path and feeds the cleaning medium to the cleaning head, and is attached to the cleaning medium by the cleaning disposed in the circulation path. A medium cleaning unit that removes an object to be cleaned, a head lifting mechanism that lifts and lowers the cleaning head, and a cleaning that moves the cleaning head horizontally together with the head lifting mechanism, the cleaning medium circulating unit, and the medium cleaning unit. A head moving means ,
The medium cleaning unit is configured to blow and separate gas from the cleaning medium by blowing gas from a surface opposite to a cleaning surface on which the cleaning object adheres to the cleaning medium; and By sucking the cleaning medium from the cleaning surface side to which the cleaning object adheres, a suction means for separating / removing the cleaning object from the cleaning medium, and collecting the separated / removed cleaning object And a collecting means for collecting the screen printing apparatus. The medium cleaning unit includes a cleaning tank for storing a cleaning liquid, and separates and removes the cleaning object from the cleaning medium by passing the cleaning medium through the cleaning tank and immersing the cleaning medium in the cleaning liquid. to claim 1 Symbol placement of the screen printing apparatus. The medium cleaning unit includes a cleaning tank having a liquid spraying unit for spraying a cleaning liquid, and the cleaning target is sprayed onto the cleaning medium by the liquid spraying unit while passing the cleaning medium through the cleaning tank. things to claim 1 Symbol placement of the screen printing apparatus and separating and removing from the cleaning medium. A screen printing unit for bringing a substrate into contact with a mask plate provided with a pattern hole and sliding a squeegee on the mask plate, and a cleaning medium in which a porous material is formed into a sheet shape by a cleaning head. A cleaning mechanism that cleans the mask plate by wiping it against
The cleaning mechanism is disposed in the circulation path for moving the cleaning medium along a predetermined circulation path and feeding the cleaning medium to the cleaning head, and adheres to the cleaning medium by the cleaning. A medium cleaning unit that removes the cleaning object, a head lifting mechanism that lifts and lowers the cleaning head, and the cleaning head horizontally moving together with the head lifting mechanism, the cleaning medium circulation unit, and the medium cleaning unit. A cleaning head moving means ,
The medium cleaning unit is configured to blow and separate gas from the cleaning medium by blowing gas from a surface opposite to a cleaning surface on which the cleaning object adheres to the cleaning medium; and By sucking the cleaning medium from the cleaning surface side to which the cleaning object adheres, a suction means for separating / removing the cleaning object from the cleaning medium, and collecting the separated / removed cleaning object A screen printing apparatus comprising a collecting means for collecting the paste, and a screen printing method for printing a paste on a substrate through the pattern hole,
A printing step of performing a printing operation of printing a paste on the substrate by the screen printing unit;
A mask cleaning step of cleaning the lower surface of the mask plate by moving the cleaning head horizontally in a state where the cleaning head is raised and the cleaning medium is pressed against the lower surface of the mask plate after the printing execution step is completed; ,
A medium cleaning step of removing a cleaning object adhered to the cleaning medium by the medium cleaning unit while moving the cleaning medium along a predetermined circulation path and feeding the cleaning medium to the cleaning head. A characteristic screen printing method. The screen printing method according to claim 4 , wherein the medium cleaning step is executed concurrently with the mask cleaning step. The screen printing method according to claim 4 , wherein the medium cleaning process is executed during a cleaning standby period in which the mask cleaning process is not executed.

Images