Automatic mask changing device for screen printers

Abstract

The present invention relates to an automatic mask changing device for a screen printer, which can automatically change a mask already installed in a screen printer to a new mask, thereby enabling a rapid switch to production of a new printed circuit board without unnecessary time and labor waste and the resulting complicated changing work, thereby improving productivity and shortening work time, thereby increasing efficiency; further, the present invention relates to an automatic mask changing device for a screen printer, which can minimize product defects caused by mask changing work by minimizing the rate of change of process conditions through quick changing work through an automatic process instead of a laborious changing work by manual labor; and the automatic mask changing device for a screen printer, which can quickly change a mask by minimizing the moving distance for changing a mask and the time required for changing a mask; and which is small in equipment size and does not require a separate installation space as it is used by being combined with the upper part of a printing unit of a screen printer.

Description

[Technical field]

[0001] The present invention relates to an automatic mask changing device for a screen printer, and more particularly, to an automatic mask changing device for a screen printer that, when a printed circuit board having a pattern printed on a mask is produced in a screen printer, automatically changes to a new mask at the same time as the production of a new printed circuit board, thereby significantly shortening the time required for manually setting up the mask, and thus enables a quick switch to the production of a new printed circuit board without the hassle of a replacement operation caused by unnecessary manual labor. As a result, not only does the device increase efficiency by improving productivity and shortening work time, but it also minimizes product defects caused by the replacement operation by minimizing the rate of change in process conditions through quick replacement operation through an automatic process rather than a forced replacement operation, and reduces restrictions on facility space when configuring an equipment line. [Background technology]

[0002] Printed circuit boards (PCBs) are all electronic circuit boards (boards with electrical wiring, semiconductors, and passive components mounted on resins such as phenolic or epoxy) that are installed in all electronic devices that are indispensable in modern life, such as home appliances. They have been continuously evolving, and in recent years, some of the most representative examples are mobile phones, computers, and portable netbooks.

[0003] As can be seen from the development of these products, the diversification of functions in response to consumer demands continues, and new products are launched on the market every day. This development is oriented toward higher density and smaller circuitry.

[0004] Surface mounted devices (SMD) are mounted on such printed circuit boards. Surface mounted devices are a collective term for electronic components that are mounted on the surface of a printed circuit board, and different components can be mounted on a printed circuit board using surface mount technology (SMT).

[0005] However, before mounting the components, solder printing must be performed to print a printed circuit pattern for mounting the components on the printed circuit board, and such solder printing is performed using a screen printing device.

[0006] During solder printing of the printed circuit patterns for mounting each surface mount component on the printed circuit board, a backup jig is required in the center conveyor device to support the printed circuit board. This is to prevent the printed circuit board from warping at the contact point with the squeegee due to the pressure of the squeegee, which presses the solder while printing, when printing the mask print pattern on the printed circuit board through solder printing.

[0007] Therefore, a mask and a backup jig are essential components for solder printing on a printed circuit board. When the size and pattern of a printed circuit board that has already been produced are changed, the mask and the backup jig must be replaced. However, when replacing the mask and the backup jig, the mask and the backup jig are usually replaced separately and manually, which causes unnecessary labor consumption and increases the time required for the replacement work, thereby reducing overall production efficiency.

[0008] Furthermore, in the process of replacing the mask and the backup jig, the replacement time is increased, and the rate of change in the working process conditions is large and the replacement cannot be performed immediately, which causes a problem of a significant increase in the defective rate of the products.

[0009] That is, when the mask and the backup jig are replaced manually, the mask and the backup jig must be set on the printed circuit board, and the mask replacement time takes about 15 to 40 minutes depending on the skill level, and the backup jig replacement time is additionally required, which reduces the continuity of the work. In addition, such replacement time increases the production time, which may reduce productivity, and also reduces the overall work efficiency.

[0010] In order to solve these problems, screen printers capable of automatically replacing masks and backup jigs have been disclosed in recent years. Examples of screen printers capable of automatically replacing masks include Korean Patent Publication No. 10-2011-0096885 (Substrate Mounting Module Replacement Device for Screen Printers) and the applicant's Korean Patent Registration No. 10-1517387 (Device for automatically replacing backup jigs and masks simultaneously when replacing printed circuit boards in a screen printer, and method for automatically replacing backup jigs and masks simultaneously using the same).

[0011] The former conventional automatic mask changer is provided with a loading unit in which a substrate mounting module for each printing job is independently loaded in each slot, and the substrate mounting module for each printing job accommodated in the loading unit is exchanged in the X direction in response to a signal. Such a conventional automatic mask changer is always applied to a mask of a certain size, and cannot be applied to a portion in which masks of different sizes fit a printed circuit board, and merely loads and inserts the mask. Furthermore, since the configuration of the loading unit and the transfer unit are arranged and formed on the X axis and are individually configured, there are many space restrictions and it is difficult to utilize the space. Therefore, there is a problem that it is very difficult to add to an already configured entire process line, and it is impossible to use it for general purposes.

[0012] Meanwhile, the latter prior patent of the present applicant is formed integrally with a printed circuit board and disclosed to solve the above-mentioned problem by automatically inserting a mask. However, in the case of the prior patent, the mask is inserted on the X-axis while moving on the Z-axis, so that the height on the Y-axis can be minimized, but the increase in the overall width causes space restrictions, which is the same problem as the former automatic mask exchange device mentioned above.

[0013] In addition, there is a limit to the time required to immediately accommodate a new mask size corresponding to a replaced printed circuit board, which increases the overall replacement time. That is, since the mask width is adjusted in one direction by moving a ball screw forward and backward, the mask width adjustment time increases and the accuracy of adjusting the mask width decreases compared to when both sides are adjusted simultaneously.

[0014] Furthermore, in the process of changing the mask, which moves in the Z-axis direction after adjusting the width and then moves again in the X-axis direction, there is a problem of moving at a right angle, which causes an error in accurate insertion of the mask, resulting in unnecessary steps of setting and checking again or printing defects.

[0015] That is, since the entire mask exchange movement process is long, the mask exchange time increases, and since the width of the entire mask exchange device is expanded due to the movement in the Z-axis direction, a large space area is required.

[0016] In addition, in the process of automatically replacing the backup jig, a separate fixed conveyor is installed between the block joining part where the backup jig is joined and the backup jig demand and supply means for automatically replacing the block joining part and the backup jig, and the vertical width between the part where the mask is installed and the backup jig is fixed. Therefore, when the backup jig is introduced between the entire process, the distance between the fixed conveyors for replacing the backup jig to the block joining part through the backup jig demand and supply means containing the backup jig is always fixed, and there is a problem that it is difficult to limit the reduction in the length on the X-axis for replacing the backup jig, and there is a problem that it is difficult to adjust the spatial distance between the part where the mask is installed and the block joining part.

[0017] That is, when a mask is input in a state where it is mounted on one side of a printed circuit board for producing home appliances, its thickness may be increased. That is, in the case of a printed circuit board using both sides, when it is mounted on one side and input for printing on the other side, a restriction occurs in the distance between the mask and the block coupling part corresponding to the thickness input only for the existing printed circuit board, which may make printing impossible, and therefore, efforts are being made to increase this. [Prior art documents] [Patent documents]

[0018] [Patent Document 1] Korean Patent Publication No. 10-2011-0096885 [Patent Document 2] Korean Patent No. 10-1517387 Summary of the Invention [Problem to be solved by the invention]

[0019] Therefore, the present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide an automatic mask change device for a screen printer that is capable of automatically changing a mask corresponding to the production of a new printed circuit board in a screen printer, thereby enabling a quick switch to the production of a new printed circuit board without unnecessary waste of time and manpower and the resulting complicated replacement work, thereby improving productivity and shortening work time, thereby increasing efficiency.

[0020] Another object of the present invention is to provide an automatic mask change device for a screen printer that can minimize product defects caused by mask change by minimizing the rate of change in process conditions through quick change through an automatic process instead of laborious change by manual labor, can quickly change a mask by minimizing the distance traveled for mask change and the time required for mask change, and can reduce equipment size and reduce restrictions on installation space by automatically changing a mask by providing a new mask for replacement above and below an already installed mask. [Means for solving the problem]

[0021] In order to achieve the above object, the automatic mask change device for a screen printer according to the present invention is an automatic mask change device that is coupled to one side of a printing unit P of a screen printer S and automatically changes a mask M arranged at the upper end of the printing unit, the automatic mask change device comprising: base plates 100 having guide rails 110 formed long in the front-rear length direction on their upper surfaces and symmetrically provided on the left and right sides of the upper side of the printing unit of the screen printer; a pool push unit 200 coupled to the guide rails 110 of the base plate 100 so as to push and pull out a mask M already installed at the printing unit P side of the screen printer S and pull and pull in a new mask NM to be replaced or installed from the printing unit P of the screen printer S, the pool push unit 200 being configured to move forward and backward along the rails by a pool push driving motor; upper support plates symmetrically formed to face the inner surfaces of the base plates 100 provided on the left and right sides and having both left and right ends of the new mask NM to be replaced engaged and supported on their inner upper surfaces, the pool push unit 200 being configured to move forward and backward along the rails by a pool push driving motor ... a lower support plate that is long in the front-rear direction and that supports both left and right ends of a mask M that has already been installed and is to be pulled out from the printing unit of the screen printer; and a lifting / lowering unit 400 that is symmetrically formed in front of the mask supplying / removing unit 300 on the inside of the base plate 100 so as to face each other, is engaged and supported by the lower support plate of the mask supplying / removing unit 300, and pushes the mask M already installed in the printing unit along the lower support plate to a pull-out / removal position by a pool push unit 200, and when a new mask NM to be replaced that is supplied from the upper support plate is pulled to the printing unit of the screen printer by the pool push unit 200 and positioned therein, the new mask NM vertically descends, and both left and right ends of the new mask NM are engaged with the lower support plate and positioned at the printing unit.

[0022] Here, the pool push unit 200 includes a vertical moving piece 210 having a rail block 212 at its lower end, which is coupled to the guide rail 110 of the base plate 100, a plate-shaped bridge bar 220 having both ends coupled to the vertical moving piece 210 at its lower end so that the vertical moving piece moves forward and backward along the guide rail in the same manner to the base plate, and a pool cylinder 232 at the center of the bridge bar 220 for pulling a new mask NM for replacement toward the printing unit, and a push cylinder 234 for pushing out the mask M already installed in the printing unit so that it can be discharged and collected. a pool push unit 230; a pool push driving motor 240 which is coupled to an upper surface of the base plate 100 and has a screw shaft 242 formed on the axis of the motor shaft and extending long in the front-rear length direction to the printing unit side; and a screw housing 250 which is formed on the outside of one of the vertical moving pieces 210 and is screw-coupled to the screw shaft 242 of the pool push driving motor 240 to convert the rotational force of the rotating screw shaft into linear motion so that the vertical moving piece 210 moves back and forth on the guide rail 110.

[0023] The mask supply and collection unit 300 includes a supply and collection body 310 formed as a rectangular plate extending in the front-rear length direction from one end where the mask is supplied and discharged to the printing unit side, a pair of block holes 312 formed on one lower surface of a side facing the printing unit side, and an idler hole 314 formed between each block hole 312; an upper support plate 320 extending in the front-rear length direction to the front side of the idler hole at the front of the printing unit of the screen printer, on an upper surface of one side of the supply and collection body, to which both left and right ends of a new mask NM to be replaced are engaged and supported; a lower support plate 330 formed directly below the upper support plate 320, extending in the front-rear length direction to a position where a mask M already installed and pulled out is pulled out and collected from the printing unit of the screen printer, so that both left and right ends of the mask M to be already installed and pulled out are engaged and supported; and a supply and collection body 310 connected to the block holes 312 of the supply and collection body 310. a holding unit 340 formed on at least one of the supply and collection bodies facing each other to press and fix the left and right frames of the mask in order to prevent the new mask NM replaced and installed in the printing unit from moving away from the upper support plate 320 by the lifting and lowering unit 400; and a holding unit 340 coupled to the idler hole 314 of the supply and collection body 310, which is pulled out to the outside of one side from the idler hole 314 so that when the new mask NM to be replaced is positioned from the upper support plate 320 to the printing unit by the pool push unit 200, the front side of the mask is supported and moved to a point where it deviates from the upper support plate, and when the new mask NM is moved downward by the lifting and lowering unit 400 to the lower support plate 330, it is pulled into the idler hole 314 to prevent interference. and an idler unit 350.

[0024] Here, the holding unit 340 is characterized in that a pressure block 342 is connected to the block hole 312 of the supply and collection body 310 and is provided so as to be able to protrude and retract inside the side surfaces of the supply and collection body facing each other, a pressure cylinder 344 is connected to the opposite side of the supply and collection body 310 facing each other, a rod is connected to the pressure block 342, and the pressure block 342 moves horizontally to be able to protrude and retract in the block hole 312 by operating the rod, and the idler unit 350 is characterized in that it includes a number of idlers 352 connected to an axis and performing a rolling motion, an axis block 354 to which the number of idlers 352 are fixed and connected, and a support cylinder 356 is provided on one side of the axis block 354 to which a rod is connected and is able to protrude and retract outside the idler hole 314 while moving horizontally by operating the rod.

[0025] Meanwhile, the lifting units 400 are coupled to the opposing sides of the base plate 100, and are arranged so that the cylinders are placed and coupled thereto. L a fixed bracket 410 bent in a " shape; a lifting cylinder 420 placed on the bent horizontal surface of the fixed bracket 410 and having a rod formed thereon that moves up and down vertically; Inverted Ta lift-and-lower fixed piece 430 having fixing bolt holes 432 symmetrically formed on the left and right sides and a rod fixing hole 434 to which the rod of the lift-and-lower cylinder 420 is connected formed on one surface of the plate protruding between the fixing bolt holes 432; an elevator section 440 formed at an outer side of the end of the printing section side of the mask supplying and taking-out unit 300, which is independently lifted and lowered by the lift-and-lower cylinder 420 and supports the mask while being flush with the upper support plate 320 when lifted and with the lower support plate 330 when lowered; and a connecting shaft 450 having an upper end fixed and connected to the fixing bolt hole 432 of the lift-and-lower fixed piece 430 and a lower end connected to the upper end of the elevator section 440, so that the elevator section is lifted and lowered by the operation of the lift-and-lower cylinder 420 to move the mask to the lower support plate 330.

[0026] In addition, it is preferable that a gap adjusting cylinder 500 is further provided above the mask supply / removal unit 300 and the lifting / lowering unit 400 to control the upward lifting and movement of the newly replaced mask NM pulled and supplied by the pool push unit 200 and to adjust the gap during movement according to the height of the mask frame to prevent the mask from tilting when positioning the printing part of the mask. Effect of the Invention

[0027] In the present invention, a screen printer is configured such that a mask corresponding to a new printed circuit board to be produced is automatically replaced by dividing the mask into upper and lower parts from the mask already installed, thereby minimizing restrictions on installation area through reduction in equipment size. In addition, since the mask can be moved horizontally and automatically replaced by moving it up and down, which is divided into upper and lower parts, it is possible to quickly switch to the production of a new printed circuit board without unnecessary time and labor waste due to mask replacement and the resulting complicated replacement work, thereby improving productivity and shortening work time, thereby increasing efficiency. In addition, by minimizing the rate of change in process conditions through quick replacement work through an automatic process rather than a laborious replacement work done by humans, it is possible to minimize product defects caused by the mask replacement work, and it is possible to increase production efficiency by shortening the overall process time by minimizing the moving distance required for mask replacement and the time required for mask replacement. [Brief description of the drawings]

[0028] [Figure 1] FIG. 1 is an overall perspective view of an automatic mask exchange device for a screen printer according to the present invention. [Diagram 2] FIG. 1 is an exploded perspective view of an automatic mask exchange device for a screen printer according to the present invention. [Diagram 3] FIG. 2 is a plan view of an automatic mask exchange device of the screen printer according to the present invention. [Figure 4] FIG. 2 is a perspective view of a main portion of a pool push unit of an automatic mask exchange device of a screen printer according to the present invention. [Diagram 5] FIG. 2 is a perspective view of a main portion of a mask supplying and removing unit of the automatic mask exchange device of the screen printer according to the present invention. [Figure 6] FIG. 2 is a perspective view of a main portion of a lifting / lowering unit of an automatic mask exchange device of a screen printer according to the present invention. [Figure 7] FIG. 2 is a perspective view of a main part of the automatic mask exchange device of the screen printer according to the present invention, showing an operating state for discharging and collecting an already installed mask. [Figure 8] FIG. 2 is a side view of a main part of the automatic mask exchange device of the screen printer according to the present invention, showing an operating state for discharging and collecting an already installed mask. [Figure 9] FIG. 11 is a perspective view of the main part of the automatic mask exchange device of the screen printer according to the present invention, showing an operating state for mounting a new mask on the printing unit. [Figure 10] FIG. 11 is a side view of the main part of the automatic mask exchange device of the screen printer according to the present invention, showing the operating state for mounting a new mask on the printing unit. [Figure 11] FIG. 11 is a side view showing the operation state of the mask by the gap adjustment cylinder of the automatic mask exchange device of the screen printer according to the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0029] The advantages, features and methods of achieving the same will become apparent from the following detailed description of the preferred embodiments of the present invention, taken in conjunction with the accompanying drawings, in which: The present invention may, however, be embodied in many different forms and should not be construed as being limited to the preferred embodiments set forth herein.

[0030] In this specification, the embodiments are provided to fully disclose the present invention and to fully inform those skilled in the art of the present invention of the scope of the invention. The present invention is defined only by the scope of the claims. Therefore, in some embodiments, well-known elements, well-known operations, and well-known techniques are not specifically described to avoid the present invention being interpreted ambiguously.

[0031] The same reference numerals refer to the same elements throughout the specification. And, each term used (referred to) in the specification is for the purpose of describing the embodiment, and is not intended to limit the present invention. In the specification, the singular includes the plural, unless otherwise stated in the phrase. Also, elements and operations referred to as "comprising" do not exclude the presence or addition of one or more other elements and operations.

[0032] Unless otherwise defined, all terms in this specification (including technical and scientific terms) can be used in the sense that they can be commonly understood by those having ordinary knowledge in the technical field to which the present invention belongs. In addition, general terms defined in advance should not be interpreted ideally or excessively unless otherwise defined.

[0033] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of an automatic mask changing device for a screen printer according to the present invention will be described in detail with reference to the accompanying drawings.

[0034] FIG. 1 is an overall perspective view of the automatic mask exchange device of a screen printer according to the present invention, FIG. 2 is an exploded perspective view of the automatic mask exchange device of a screen printer according to the present invention, FIG. 3 is a plan view of the automatic mask exchange device of a screen printer according to the present invention, FIG. 4 is a perspective view of a main part of a pool push unit of the automatic mask exchange device of a screen printer according to the present invention, FIG. 5 is a perspective view of a main part of a mask supply and removal unit of the automatic mask exchange device of a screen printer according to the present invention, FIG. 6 is a perspective view of a main part of a lifting and lowering unit of the automatic mask exchange device of a screen printer according to the present invention, and FIG. FIG. 8 is a perspective view of the essential parts showing the operational state for discharging and recovering a mask that has already been installed, FIG. 9 is a perspective view of the essential parts showing the operational state for loading a new mask into the printing unit of the automatic mask changer of the screen printer according to the present invention, FIG. 10 is a side view of the essential parts showing the operational state for loading a new mask into the printing unit of the automatic mask changer of the screen printer according to the present invention, and FIG. 11 is a side view of the automatic mask changer of the screen printer according to the present invention showing the operation state of the mask by the gap adjustment cylinder.

[0035] The automatic mask changing device for a screen printer according to the present invention has been made in response to the need to change the mask when printing a printed circuit board pattern using a screen printer after printing an initially installed mask pattern, and is configured to automatically change the mask of the screen printer quickly and precisely to appropriately accommodate the production of a new printed circuit board while minimizing restrictions on installation area.

[0036] Therefore, it is possible to quickly switch to the production of a new printed circuit board without unnecessary time, labor waste, and the resulting complication of the replacement work in the mask replacement process, and thus the overall process time can be shortened, thereby improving productivity and increasing efficiency by shortening the work time. It is possible to minimize the rate of change in process conditions by performing a quick replacement work through an automatic process instead of a laborious replacement work by manual labor, thereby minimizing product defects caused by the replacement work of the mask of the screen printer. The mask is collected and supplied on a horizontal line or moved horizontally up and down, and the mask is accurately positioned and installed in the printing unit, so that the mask can be replaced quickly and precisely. Since the mask is formed on the upper side of the printing unit of the screen printer, no separate installation area is required, and since it is installed on the upper side of the printing unit of the screen printer, there is no restriction on the installation area. The automatic mask replacement apparatus according to the present invention, which is configured to be coupled to the upper side of the printing unit of the screen printer and to automatically replace the mask M arranged on the upper end of the printing unit, includes a base plate 100, a pool push unit 200, a mask supply / receive unit 300, and a lifting / lowering unit 400, as shown in FIGS. 1 to 3.

[0037] The base plate 100 is connected to a number of frames, and is formed to accommodate a pool push unit 200, a mask supply / removal unit 300, and an elevation unit 400, which will be described later, and has guide rails 110 formed long in the front-rear direction on its upper surface, which are provided symmetrically on the left and right sides above the printing unit of the screen printer. Since the base plate 100 is installed on the upper side of the screen printer, there is no restriction on the installation area since no additional installation area is required for a device for replacing the mask. In other words, one side of the base plate is a mask collection point that does not deviate from the screen printer, and the other side is formed symmetrically on the left and right sides to correspond to the area directly above the printing unit of the screen printer.

[0038] The pool push unit 200 is coupled to the guide rail 110 of the base plate 100 so as to push and pull out the mask M already installed at the printing unit P of the screen printer S and pull in a new mask NM to be replaced or installed from the printing unit P of the screen printer S, and is configured to move back and forth along the rail by a pool push driving motor. Here, when moving along the guide rail, the pool push unit 200 advances to a position for transferring the mask to the printing unit of the screen printer, and after discharging the mask, moves along the rail to a position where it can be collected by another collection device or an automatic or manual collection system by human power.

[0039] The pool push unit 200 includes a vertical moving piece 210, a bridge bar 220, a pool push part 230, a pool push driving motor 240, and a screw housing 250, as shown in FIGS.

[0040] The vertical moving pieces 210 move on the guide rails by receiving the driving force of a pull push driving motor, which will be described later, and have rail blocks 212 at their lower ends, which are coupled to the guide rails 110 of the base plate 100. Here, a screw housing 250, which will be described later, is coupled to one side of the vertical moving pieces 210, i.e., the vertical moving piece 210 on the side where the pull push driving motor is installed, and moves on the guide rails while converting the rotational motion of the screw shaft into linear motion, and is connected and formed by a bridge bar, which will be described later, so that it can move simultaneously with the opposite vertical moving piece 210, which is formed symmetrically facing each other.

[0041] The bridge bar 220 is provided so that the vertical moving pieces 210 formed facing each other can move on the guide rail at the same time. The vertical moving pieces 210 are connected to the lower ends of both ends of the bridge bar 220, and the vertical moving pieces are provided in a plate shape so that they can move simultaneously to the front and rear of the base plate along the guide rail.

[0042] The pool push unit 230 pulls and pushes the new mask NM to be replaced and the already installed mask M while the vertical moving pieces 210 at both ends are moved back and forth by the bridge bar 220 under the driving force of a pool push driving motor described below, and includes a pool cylinder 232 for pulling the new mask NM to be replaced toward the printing unit at the center of the bridge bar 220, and a push cylinder 234 for pushing out the mask M already installed in the printing unit so that it can be discharged and collected. Here, the rods of the pool cylinder and the push cylinder are engaged and coupled to the inside of the frame side of the new mask to be replaced and pull it toward the printing unit of the screen printer, and the rod of the push cylinder is formed so that the end of the rod is pushed out to the outside of the frame side of the mask.

[0043] The pool push driving motor 240 generates a driving force so that the bridge bar 220, in which the pool push part 230 is formed at the center, and the vertical moving piece 210 move back and forth on the guide rail 110 of the base plate 100 together. The pool push driving motor 240 is coupled to one side of the upper part of the base plate 100, and a screw shaft 242 is formed on the axis of the motor shaft so as to extend in the front and rear length direction to the printing part side.

[0044] The screw housing 250 converts the rotational motion of the screw shaft 242 into linear motion. It is formed on the outside of one of the vertical moving pieces 210 and is screw-coupled to the screw shaft 242 of the pool push driving motor 240 to convert the rotational force of the rotating screw shaft into linear motion. When the vertical moving piece 210 moves back and forth on the guide rail 110, the bridge bar and the pool push part are It is designed to move back and forth on the guide rail to enable mask replacement, discharge and collection. do.

[0045] The mask supply and removal unit 300 is formed symmetrically to support a new mask NM and an already installed mask M at a supply and discharge position, and as shown in Figures 1 to 3 and 5, it includes a supply and removal body 310, an upper support plate 320, a lower support plate 330, a holding unit 340, and an idler unit 350.

[0046] The supply / removal body 310 is formed as a rectangular plate that is elongated in the front-rear length direction from one end where the mask is supplied / discharged to the printing unit side, and a pair of block holes 312 to which a holding unit 340 described later can be retracted are formed on one lower surface of the side facing the printing unit, and idler holes 314 to which an idler unit 350 described later can be retracted are formed between each block hole 312.

[0047] The upper support plate 320 is placed when a new mask NM is replaced. Both left and right ends of the new mask NM to be replaced are engaged and supported on the upper surface of one side of the supply / removal body, and the upper support plate 320 is elongated in the front-rear length direction up to the front side of the idler hole at the front of the printing unit of the screen printer.

[0048] The lower support plate 330 is provided so that both left and right ends are engaged so that the position of an already installed mask M is fixed in the printing unit of the screen printer by a holding unit, and then, when a new mask NM is inserted to be replaced, it is transported from the printing unit to a discharge position and placed thereon. The lower support plate 330 is formed directly below the upper support plate 320 and is elongated in the front-rear length direction to a position where the mask M is pulled out from the printing unit of the screen printer and discharged / recovered so that both left and right ends of the mask M that has already been installed and pulled out are engaged and supported.

[0049] The holding unit 340 presses and fixes the left and right sides of the mask so that the new mask NM to be replaced is engaged, supported and fixed at the printing unit position of the lower support plate 320, and is provided retractably so as to be released when discharging and collecting. The holding unit 340 is connected to the block hole 312 of the supply and collection body 310, and is formed retractably on the sides of the supply and collection body facing each other. The holding unit 340 is moved downward from the upper support plate to the lower support plate by the lifting unit 400, and is formed on at least one side of the supply and collection body facing each other to press and fix the left and right frames of the mask to prevent the new mask NM replaced and installed at the printing unit from moving.

[0050] The holding unit 340 is fitted to the block hole 312 of the supply and collection body 310, and has a rectangular pressure block 342 that can be inserted and removed from the inside of the sides of the supply and collection body facing each other. A pressure cylinder 344 is fitted to the opposite side of the supply and collection body 310, and a rod is fitted to the pressure block 342, and the pressure block 342 moves horizontally to the left and right frame sides of the mask through the block hole 312 by operating the rod. That is, when a new mask M is supplied through the upper support plate 320 and is lowered and transferred to the lower support plate 330 through a lifting unit to be described later, and the mask is positioned on the printing unit side of the screen printer by operating the push cylinder of the pool push unit, the horizontally moving rod presses and presses the pressure block 342, which is fitted to be inserted and removed from the block hole of the supply and collection body, against the left and right frame sides of the mask, thereby fixing the replaced mask in the correct position without deviating from the printing unit.

[0051] The idler unit 350 appears and disappears from the lower surfaces of the left and right frames of the mask to temporarily support the mask when a new mask NM is inserted into the upper support plate to be replaced with a new mask and the mask is positioned in the space above the printing unit while moving along the upper support plate by the pool push unit 200. The idler unit 350 is coupled to the idler hole 314 of the supply / receive body 310, and when a new mask NM to be replaced is positioned from the upper support plate 320 to the printing unit by the pool push unit 200, the idler unit 350 is pulled outward from one side from the idler hole 314 so that the front side of the mask is supported and moved to a point where it deviates from the upper support plate, and when the new mask NM is moved downward by the lifting / lowering unit 400 on the lower support plate 330, the idler unit 350 is pulled into the idler hole 314 to prevent interference.

[0052] The idler unit 350 corresponds to the lower surfaces of the left and right sides of the mask and is connected to an axle so as to be smoothly moved through a rolling motion, and a number of idlers 352 that perform rolling motion are horizontally arranged and connected to a rectangular axle block 354 corresponding to the idler holes, and a rod is connected to the axle block to which a number of idlers are connected on one side of the axle block 354, and the idler unit 350 is provided so as to be able to move horizontally by operating the rod and to be able to protrude and retract so as to contact the outside of the idler hole 314, i.e., the lower surfaces of the left and right side frames of the mask.

[0053] Therefore, the idler unit 350 is provided to support the lower surfaces of the left and right frames of the mask at the end point of the upper support plate so that the mask can be vertically lowered from the upper support plate to the lower support plate for replacement, and to support the mask until it reaches a position for lowering to the lower support plate. After the mask reaches the position for vertically lowering to the lower support plate, the mask is vertically lowered to the lower support plate by the lifting unit, and an axis block having a number of idlers formed thereon is inserted into the idler hole to enable smooth vertical descent without interference.

[0054] The lifting and lowering units 400 are operated up and down to position the new mask NM to be replaced on the lower support plate after it is supplied to the upper support plate and transferred to the printing unit by the pool push unit, and the mask is positioned on the lower support plate in the correct position for the printing unit of the screen printer. The lifting and lowering units 400 are symmetrically formed in front of the mask supplying and removing unit 300 on the inside of the base plate 100 so as to face each other, and are engaged and supported by the lower support plate of the mask supplying and removing unit 300. The mask M already installed in the printing unit is pushed out along the lower support plate by the pool push unit 200 to a withdrawal and collection position, and is supplied from the upper support plate. When the new mask NM to be replaced is pulled and positioned in the printing unit of the screen printer by the pool push unit 200, the new mask NM is vertically lowered, and both left and right ends of the new mask NM are engaged with the lower support plate and positioned in the printing unit.

[0055] The lifting / lowering unit 400 includes a fixing bracket 410, a lifting / lowering cylinder 420, a lifting / lowering fixing piece 430, an elevator part 440, and a connecting shaft 450, as shown in FIGS.

[0056] The fixing bracket 410 is provided to fix the lift cylinder 420 described later, and serves as a reference to be positioned on the same line when an elevator unit described later moves between an upper support plate and a lower support plate by vertically ascending the rod of the lift cylinder. The lift units 400 are coupled to the opposing sides of the base plate 100, and the cylinders are placed and coupled to the fixing bracket 410. L It is formed by folding it into a " shape.

[0057] The lift cylinder 420 is installed so that its rod moves vertically upward and downward, and is placed on the bent horizontal surface of the fixed bracket 410 to form a rod that moves vertically upward. Meanwhile, the rod of the lift cylinder 420 moves in steps, and in the case of a one-step signal, it is preferable to align an elevator unit, which will be described later, on the same line as the upper support plate, and in the case of a two-step signal, it is preferable to align the elevator unit on the same line as the lower support plate, and it is also preferable to operate in the reverse order.

[0058] The lifting and lowering fixed piece 430 is provided so that the elevator part 440 can move vertically up and down while maintaining horizontal balance with one lifting and lowering cylinder. Inverted T The lift-down fixed piece 430 is formed on a "-shaped plate, with fixing bolt holes 432 formed symmetrically on the left and right, and a rod fixing hole 434 to which the rod of the lift-down cylinder 420 is connected is formed on one side of the plate protruding between the fixing bolt holes 432. In other words, when the upper end of the rod of the lift-down cylinder 420 is fixed and connected to the rod fixing hole 434 of the lift-down fixed piece 430 and moves up and down to the upper side, the front and rear of the elevator unit, which will be described later, move up and down uniformly in parallel, allowing the upper support plate and the lower support plate to move on the same horizontal line.

[0059] The elevator unit 440 is for vertically lowering and moving the mask NM to the lower support plate when the new mask NM is supplied from the upper support plate and pulled by the pool push unit. The elevator unit 440 is independently raised and lowered by the lift cylinder 420 at the outer side of the end of the printing unit side of the mask supply and removal unit 300, and is formed to support the mask while being flush with the upper support plate 320 when raised and flush with the lower support plate 330 when lowered. That is, the elevator unit 440 is provided so that the mask can be smoothly raised and lowered by being positioned on the same horizontal line as the upper and lower support plates through the step movement of the rod of the lift cylinder as described above. In addition, the elevator unit 440 stably supports the mask supported and transferred by the idler unit, and therefore stably raises and lowers without drifting or tilting even when the idler and shaft block of the idler unit are pulled into the idler hole and the support is released.

[0060] The connecting shaft 450 is provided such that an elevator unit is connected to the lift-and-lower fixed piece and moves up and down together with the lift-and-lower fixed piece in accordance with the lift-and-lower operation of the lift-and-lower fixed piece. The upper end of the connecting shaft 450 is fixedly connected to the fixing bolt hole 432 of the lift-and-lower fixed piece 430 and the lower end of the connecting shaft 450 is connected to the upper end of the elevator unit 440. The elevator unit moves up and down in accordance with the operation of the lift-and-lower cylinder 420, so that the mask can be moved to the lower support plate 330.

[0061] Meanwhile, as shown in FIG. 11, it is preferable that a gap adjusting cylinder 500 is further provided above the mask supply / removal unit 300 and the lifting / lowering unit 400 to adjust the gap during movement according to the height of the mask frame in order to control the upward lifting and flow of the newly replaced mask NM pulled and supplied by the pool push unit 200 and to prevent the mask from tilting when positioning the printing part of the mask. That is, the gap adjusting cylinder 500 is connected to the supply and removal body above the upper support plate, and is formed to correspond to the thickness of the left and right frames of the mask placed on the upper support plate, thereby preventing the mask from being pulled on the upper support plate by the pool push unit and lifting up and down, or preventing the front of the mask from tilting as the rear side of the mask suddenly lifts up and down at the end of the upper support plate as the printing unit approaches.The gap adjusting cylinder 500 is also installed above the lifting unit in order to prevent the mask from being tilted or bent due to imbalance when it is supplied from the upper support plate, which is a stage before the mask is lowered and transferred to the lower support plate, and placed on the lifting unit, making it difficult to accurately fix the mask to the printing unit.

[0062] In the automatic mask changing device for a screen printer according to the present invention having such a configuration, as shown in FIGS. 1 to 3, a mask M having a pattern for solder printing on an initial printed circuit board is installed in the screen printer S, and then a printed circuit board is produced using the mask M already installed in the screen printer S. In order to produce a new printed circuit board, a new mask NM must be replaced. At this time, the new mask NM is inserted and placed on one side of the upper support plate 320 of the supply and collection body 310 of the mask supply and collection unit 300 which is formed symmetrically opposite each other, as shown in FIGS. 1 and 9.

[0063] 7 and 8, the motor shaft rotates due to the operation of the pool push driving motor 240, and the screw shaft 242 axially coupled to the motor shaft rotates. Then, the screw housing 250 coupled to the screw shaft 242 moves back and forth on the axis of the screw shaft due to the rotational force of the screw shaft 242. Here, when the screw housing 250 moves forward on the axis of the screw shaft toward the printing unit P, the rail block 212 at the lower end of the vertical moving piece 210 to which the screw housing 250 is fixed moves forward along the guide rail 110 toward the front of the printing unit, and the opposite vertical moving piece 210 coupled to the bridge bar 220 also moves forward along the guide rail.

[0064] Next, the push cylinder 234 of the pool push part 230 formed in the center of the bridge bar 220 of the pool push unit 200 is operated so that the rod corresponds to the outside of the frame of the already installed mask M placed and fixed on the printing part side of the lower support plate 330, and then in order to release the fixation of the mask, the pressure block 342, which presses the left and right sides of the mask, is pulled into the inside of the block hole 312 of the supply and collection body 310 by the pressure cylinder 344 of the holding unit 340, thereby releasing the fixation of the printing part of the mask. Here, it is preferable that the holding unit 340 is formed on one side of the supply and collection body provided symmetrically facing each other, and the opposite side is fixed as a reference line.

[0065] Next, the pool push drive motor 240 is operated to move the mask along the guide rail of the pool push unit to the rear side of the lower support plate 330 for retrieving the mask, and the push cylinder 234 moves the mask to the lower support plate 330 with the rod in contact with the outside of the frame of the already installed mask M. Push the ball towards the back of the car and have it collected.

[0066] 9 and 10, the rod of the push cylinder returns to its original position (a position where it is not interfered with by the new mask placed on the upper support plate), and the rod moves downward by the operation of the pool cylinder 232 of the pool push part 230 formed in the center of the bridge bar 220 of the pool push unit 200, and the end of the downwardly moved rod is engaged and coupled to the front side frame of the new mask NM to be replaced, and the pool push driving motor 240 is operated so that it moves along the upper support plate 320. Here, the motor shaft rotates by the operation of the pool push driving motor 240, and the screw shaft 242 axially coupled to the motor shaft rotates idly. Then, the screw housing 250 coupled to the screw shaft 242 moves back and forth on the axis of the screw shaft by the rotational force of the screw shaft 242.

[0067] Next, when the screw housing 250 moves forward on the axis of the screw shaft toward the printing unit P, the rail block 212 at the lower end of the vertical moving piece 210 to which the screw housing 250 is fixed moves forward toward the front of the printing unit along the guide rail 110, and the opposite vertical moving piece 210 interlocked and connected to the bridge bar 220 also moves forward along the guide rail. As a result, the new mask NM engaged and connected to the rod of the pool cylinder 232 moves toward the printing unit along the upper support plate.

[0068] Next, the front end of the new mask NM placed on the upper support plate 320 that ends close to the printing unit side continues to move forward of the printing unit side of the pool push unit 200, and as the mask deviates from the upper support plate 320, the shaft block 354 on which a number of idlers 352 of the idler unit 350 are formed protrudes from the idler hole 314 so as to be supported corresponding to the lower surfaces of the left and right side frames of the mask. Therefore, due to the protrusion of the idler unit 350, the new mask NM continues to move toward the printing unit on the same horizontal line as the upper support plate 320 without falling toward the lower support plate 330, and the front end of the mask moves and is placed on the elevator part 440 of the lifting / lowering unit 400 located on the same horizontal line as the upper support plate 320, and the mask continues to move and is placed on the elevator part 440 without falling.

[0069] Next, the shaft block 354 of the idler unit 350 is pulled into the idler hole 314 together with the idler 352 by the operation of the support cylinder 356, so that when the new mask NM is lowered onto the lower support plate 330 by the lifting unit 400, it can be lowered smoothly without interference.

[0070] Thereafter, the new mask NM placed on the elevator section 440 of the lifting / lowering unit 400 descends to the lower support plate 330. At this time, the lifting / lowering cylinder 420 of the lifting / lowering unit 400 operates, causing the rod to move downward. As the rod moves downward, the elevator section 440, which is connected to the lifting / lowering fixed piece 430 by the connecting shaft 450, also moves downward and is positioned on the same horizontal line as the lower support plate 330.

[0071] Next, the rod of the pool cylinder 232 of the pool push unit 200 returns to its original state, and the pulling action of the new mask NM is released, and the rod of the push cylinder 234 is operated again to move downward and press the outside of the frame of the new mask NM toward the printing unit, thereby positioning the mask. Here, when the new mask NM is positioned in the printing unit, the pressure cylinder 344 of the holding unit 340 is operated, and the pressure block 342 protrudes from the block hole and presses the frame of the left and right side of the mask, or forms a holding unit on only one side, and the holding unit is provided. The unsupplied and removed parts are fixed to the printing part while being pressed and fixed to the reference side based on the main body side. This completes the automatic mask exchange.

[0072] Meanwhile, as mentioned above and shown in FIG. 11, the gap adjusting cylinder 500 controls the upward lifting and movement of the newly replaced mask NM, which is pulled and supplied by the pool push unit 200 above the mask supply / removal unit 300 and the lift / lower unit 400, and the flow during movement, and adjusts the gap during movement according to the height of the mask frame to prevent the mask from tilting when positioning the mask printing part, thereby making it possible to maintain horizontality when changing the position of the mask, improving the accuracy of mask alignment and mask insertion, and enabling higher quality screen printing.

[0073] As described above, since the mask is inserted and removed in one direction, the time required for mask replacement can be significantly reduced compared to a configuration in which the mask insertion and removal processes are performed on opposite sides. Also, the mask is always inserted, removed, and removed in a fixed direction, allowing accurate insertion and removal, thereby reducing the time required for mask setting.

[0074] Meanwhile, the automatic mask changing device is configured to automatically change the already installed mask M to a new mask NM at the same time by operation, thereby shortening the mask changing time. By automatically changing the masks at the same time through this method, it is possible to quickly switch to the production of new printed circuit boards without unnecessary time and labor waste and the resulting trouble of the changing work. As a result, it is obvious that efficiency is increased by improving productivity and shortening the working time, and product defects caused by the mask changing work of the screen printer can be minimized by minimizing the rate of change of process conditions by performing the changing work through a quick automatic process instead of a laborious changing work by manual labor.

[0075] Furthermore, by configuring the mask changing device, which was previously installed on one side of a conventional screen printer, above the printing unit of the screen printer, no additional installation space is required, and there are no installation restrictions. Furthermore, since the automatic mask changing device can be installed without modifying the existing production line, it can be added to an existing line, making it versatile and reducing installation costs.

[0076] On the other hand, although specific embodiments have been described in the detailed description of the present invention, it is obvious to a person having ordinary skill in the art that various modifications are possible without departing from the scope of the present invention, and such modifications are within the scope of the claims. [Explanation of symbols]

[0077] M: Mask NM: New Mask S: Screen printer P: Printing Department 100: Base plate 110: Guide rail 200: Pool push unit 210: Vertical moving piece 212: Rail block 220: Bridge bar 230: Pool Push Department 232: Pool cylinder 234: Push cylinder 240: Pool push drive motor 242: Screw shaft 250: Screw housing 300: Mask supply and collection unit 310: Supply and collection body 312: Block hole 314: Idler hole 320: Upper support plate 330: Lower support plate 340: Holding Unit 342: Pressure block 344: Pressurized cylinder 350: Idler unit 352: Idler 354: Axis block 356: Support cylinder 400: Lifting unit 410: Fixed bracket 420: Lifting cylinder 430: Lifting and lowering fixed piece 432: Fixing bolt hole 434: Rod fixing hole 440: Elevator Department 450: Connecting shaft 500: Gap adjustment cylinder

Claims

1. An automatic mask changer for automatically changing a mask (M) arranged on an upper end of a printing unit (P) of a screen printer (S), comprising: The automatic mask changer includes a base plate (100) having a guide rail (110) formed on an upper surface thereof in a longitudinal direction, the base plate being symmetrically provided on the left and right sides above the printing unit of the screen printer; a pool push unit (200) coupled to the guide rail (110) of the base plate (100) so as to push out a mask (M) already installed on the printing unit (P) of the screen printer (S) while pushing it out and to pull in a new mask (NM) to be replaced and installed from the printing unit (P) of the screen printer (S) while pulling it in, and configured to move back and forth along the rail by a pool push driving motor; a mask supply and removal unit (300) which is symmetrically formed on the inner surfaces of the base plates (100) provided on the left and right sides, has an upper support plate on its inner upper surface for engaging and supporting both left and right ends of a new mask (NM) to be replaced, and is formed long in the front-rear length direction up to the front of the printing unit of the screen printer, and has a lower support plate on which both left and right ends of a mask (M) already installed and pulled out from the upper support plate are engaged and supported, and is formed long in the front-rear length direction up to a position where the mask is pulled out and collected from the printing unit of the screen printer; and a lifting and lowering unit (400) which is symmetrically formed on the inside of the base plate (100) in front of the mask supplying and removing unit (300) so as to face each other, and which is engaged and supported by the lower support plate of the mask supplying and removing unit (300), and which is arranged so that a mask (M) already installed in the printing unit is pushed along the lower support plate by a pool push unit (200) to a pull-out and recovery position, and a new mask (NM) to be replaced, which is supplied from the upper support plate, is pulled to the printing unit of the screen printer by the pool push unit (200) and positioned therein, and the new mask (NM) is lowered vertically so that both left and right ends of the new mask (NM) are engaged with the lower support plate and positioned at the printing unit.

2. The pool push unit (200) includes a vertical moving piece (210) having a rail block (212) formed at its lower end, the rail block (212) being coupled to the guide rail (110) of the base plate (100); a plate-shaped bridge bar (220) to which the vertical moving pieces (210) are connected at the lower ends thereof so that the vertical moving pieces can move in the same manner back and forth along the guide rails to the base plate; a pool push unit (230) formed at the center of the bridge bar (220) including a pool cylinder (232) for pulling a new replacement mask (NM) toward the printing unit, and a push cylinder (234) for pushing out the mask (M) already installed in the printing unit so that it can be discharged and collected; a pool push driving motor (240) coupled to an upper surface of the base plate (100) and having a screw shaft (242) extending in the front-rear direction to the printing unit on the axis of the motor shaft; and a screw housing (250) formed on the outer side of any one of the vertical moving pieces (210) and screw-coupled to a screw shaft (242) of the pool push driving motor (240) to convert a rotational force of the rotating screw shaft into a linear motion so that the vertical moving piece (210) moves back and forth on the guide rail (110).

3. The mask supply and removal unit (300) is a rectangular plate-shaped body elongated in the front-rear direction from one end where the mask is supplied and discharged to the printing unit side, and has a pair of block holes (312) formed on the lower surface of the side facing the printing unit, and an idler hole (314) formed between each block hole (312); an upper support plate (320) on which both left and right ends of a new mask (NM) to be replaced are engaged and supported on an upper surface of one side of the supply / removal body, and which is elongated in the front-rear direction up to the front side of an idler hole at the front side of the printing unit of the screen printer; a lower support plate (330) formed directly below the upper support plate (320) and elongated in the front-rear direction to a position where the mask (M) is pulled out from the printing unit of the screen printer and recovered so that both left and right ends of the mask (M) that has already been installed and pulled out are engaged and supported; a holding unit (340) which is coupled to the block hole (312) of the supply and collection body (310), is formed so as to be able to appear and disappear on the sides of the supply and collection body facing each other, and is formed on at least one side of the supply and collection body facing each other to press and fix the left and right frames of the mask to prevent the new mask (NM) replaced and installed in the printing unit from moving away from the upper support plate to the lower support plate by the lifting and lowering unit (400); an idler unit (350) coupled to the idler hole (314) of the supply / receive body (310), pulled outward from one side of the idler hole (314) so ​​that when a new mask (NM) to be replaced by the pool push unit (200) is positioned at the printing unit from the upper support plate (320) a front side of the mask is supported and moved to a point where it deviates from the upper support plate, and pulled into the idler hole (314) to prevent interference when the new mask (NM) is moved downward by the lifting / lowering unit (400) on the lower support plate (330).

4. 4. The automatic mask changing device for a screen printer according to claim 3, wherein the holding unit (340) is connected to a block hole (312) of the supply and collection body (310), a pressurizing block (342) is provided on the inner side of the opposing side of the supply and collection body (310) so as to be capable of rising and falling, and a pressurizing cylinder (344) is connected to the opposing side of the supply and collection body (310) so that a rod is connected to the pressurizing block (342), and the pressurizing block (342) moves horizontally to be capable of rising and falling in the block hole (312) by operating the rod.

5. The idler unit (350) includes a number of idlers (352) that are coupled to a shaft and perform rolling motion; a shaft block (354) to which the multiple idlers (352) are fixed and coupled; 4. The automatic mask changing device for a screen printer according to claim 3, further comprising: a support cylinder (356) provided outside the idler hole (314) so ​​as to be capable of moving horizontally by actuating a rod connected to the shaft block (354) having a number of idlers connected to one side of the shaft block, and capable of appearing and disappearing therefrom.

6. The lifting unit (400) includes: fixed brackets (410) coupled to opposing sides of the base plate (100) and bent into an "L" shape so that a cylinder can be placed and coupled thereto; A lifting cylinder (420) is placed on the bent horizontal surface of the fixed bracket (410) and has a rod that moves up and down vertically upward; a lift-lowering fixed piece (430) formed on an inverted T-shaped plate, with fixing bolt holes (432) formed symmetrically on the left and right sides, and with a rod fixing hole (434) formed on one surface of the plate protruding between the fixing bolt holes (432) to which the rod of the lift-lowering cylinder (420) is connected; an elevator section (440) formed at the outer side of the end of the mask supply / removal unit (300) on the printing section side, which is independently moved up and down by the lifting / lowering cylinder (420) and is formed flush with the upper support plate (320) when lifted and flush with the lower support plate (330) when lowered, to support the mask; and a connecting shaft (450) having an upper end fixed and connected to the fixing bolt hole (432) of the lift-and-lower fixed piece (430) and a lower end connected to the upper end of the elevator unit (440), so that the elevator unit can be lifted and lowered by operation of the lift-and-lower cylinder (420) to move the mask to the lower support plate (330).

7. 2. The automatic mask changing device for a screen printer according to claim 1, further comprising a gap adjusting cylinder (500) disposed above the mask supplying / removing unit (300) and the lifting / lowering unit (400) for controlling the upward lifting / lowering and flow of the newly replaced mask (NM) pulled and supplied by the pool push unit (200) and for adjusting the gap during movement according to the height of a mask frame to prevent the mask from tilting when positioning a printing unit of the mask.

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