Paste transfer device, screen printing device, and paste transfer method

Abstract

To provide a paste transfer device, a screen printing device, and a paste transfer method capable of improving productivity of screen printing work by suppressing wear of a sheet member.SOLUTION: Paste Pst on a current mask 13 (first mask) is placed and recovered on a sheet member 25 which covers a paste recovery surface 24M of a movable scraper 24, and then a paste transfer operation for lowering and supplying the recovered paste Pst on a next mask 13 (second mask) different from the first mask is executed. In this execution, whether preset prescribed conditions are satisfied is determined (ST11 and ST12) before the execution of the paste transfer operation. When it is determined that the conditions are satisfied, the paste transfer operation is executed without updating the sheet member. When it is determined that the conditions are not satisfied, the sheet member is updated (ST7), and then the paste transfer operation is executed (ST8-ST10).SELECTED DRAWING: Figure 8

Description

[Technical field]

[0001] The present invention relates to a paste transfer device, a screen printing device, and a paste transfer method for transferring paste between two exchanged masks. [Background technology]

[0002] Conventionally, a screen printing apparatus prints a paste such as solder on a substrate by contacting the substrate with the underside of a mask in which pattern openings are formed and moving a squeegee over the mask. When changing the type of substrate, the used mask is removed from the screen printing apparatus and a new mask corresponding to the substrate after the change in type is set in the screen printing apparatus. In this case, the paste remaining on the used mask is collected by a scraper provided in the screen printing apparatus and then supplied (i.e., transferred) to a new mask for reuse (see, for example, Patent Document 1 below).

[0003] In the paste transfer device described in Patent Document 1, the upper surface of the scraper (grounding body) is covered with a sheet member, and the sheet member is wound on a reel and renewed every time the paste is transferred. Therefore, even if part of the paste adheres to the sheet member during the paste transfer, there is no inconvenience of this adhering to the paste to be transferred next. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 6-262750 Summary of the Invention [Problem to be solved by the invention]

[0005] However, if the sheet members are replaced every time the paste is transferred, the sheet members will wear out quickly, and there is a risk that the productivity of the screen printing apparatus will decrease due to the work of replacing the sheet members.

[0006] SUMMARY OF THE PRESENT DISCLOSURE An object of the present invention is to provide a paste transfer device, a screen printing device, and a paste transfer method that can reduce wear on the sheet material and improve the productivity of screen printing operations. [Means for solving the problem]

[0007] The paste transfer device of the present invention is a paste transfer device that performs a paste transfer operation in which paste on a first mask is placed on a sheet member covering the paste recovery surface of a movable scraper and recovered, and then the recovered paste is lowered and supplied onto a second mask different from the first mask, and is equipped with a sheet member updating unit that renews the portion of the sheet member covering the paste recovery surface, and a control unit that controls the paste transfer operation and the sheet member renewal operation by the sheet member renewal unit, and before performing the paste transfer operation, the control unit judges whether predetermined conditions are satisfied, and controls the paste transfer operation and the sheet member renewal operation by the sheet member renewal unit based on the judgment result.

[0008] Another paste transfer device of the present invention is a paste transfer device that performs a paste transfer operation in which paste on a first mask is placed on a sheet member covering a paste recovery surface of a movable scraper and recovered, and then the recovered paste is lowered and supplied onto a second mask different from the first mask, and is equipped with a sheet member updating unit that renews a portion of the sheet member covering the paste recovery surface, a control unit that controls the paste transfer operation and the sheet member renewal operation by the sheet member renewal unit, and a mode selection unit that can select either a normal mode or a saving mode, and when the normal mode is selected by the mode selection unit, the control unit causes the sheet member renewal unit to perform the sheet member renewal operation and then executes the paste transfer operation, and when the mode selection unit selects the saving mode, before executing the paste transfer operation, the control unit determines whether a predetermined condition is satisfied or not before executing the paste transfer operation, and controls the paste transfer operation and the sheet member renewal operation by the sheet member renewal unit based on the determination result.

[0009] The screen printing apparatus of the present invention is a screen printing apparatus that performs a printing operation of applying paste to a substrate through a mask, and the printing operation is continued by transferring paste from the first mask to the second mask using the paste transfer device of the present invention.

[0010] The paste transfer method of the present invention is a paste transfer method that performs a paste transfer process in which paste on a first mask is placed on a sheet member covering the paste recovery surface of a movable scraper and recovered, and then the recovered paste is lowered and supplied onto a second mask different from the first mask, and before performing the paste transfer process, it is determined whether a predetermined condition is satisfied, and if it is determined that the predetermined condition is satisfied, the paste transfer process is performed without updating the sheet member, and if it is determined that the predetermined condition is not satisfied, the sheet member is updated and then the paste transfer process is performed. Effect of the Invention

[0011] According to the present invention, it is possible to suppress wear of the sheet member and improve the productivity of the screen printing operation. [Brief description of the drawings]

[0012] [Figure 1] FIG. 1 is a side view of a screen printing apparatus including a paste transfer device according to an embodiment of the present invention. [Diagram 2] FIG. 1 is a side view showing a scraper unit provided in a screen printing apparatus (paste transfer apparatus) according to an embodiment of the present invention together with a print head. [Diagram 3] (a) (b) is a side view of a scraper unit provided in a paste transfer device according to one embodiment of the present invention. [Figure 4] FIG. 2 is a block diagram showing a control system of a screen printing apparatus according to an embodiment of the present invention. [Diagram 5] 1A, 1B, and 1C are diagrams illustrating a paste transfer operation of a scraper unit included in a paste transfer device according to an embodiment of the present invention. [Figure 6] 1A, 1B, and 1C are diagrams illustrating a paste transfer operation of a scraper unit included in a paste transfer device according to an embodiment of the present invention. [Figure 7] 1A, 1B, and 1C are diagrams illustrating a paste transfer operation of a scraper unit included in a paste transfer device according to an embodiment of the present invention. [Figure 8] A flowchart showing the flow of a screen printing operation performed by a screen printing apparatus (paste transfer apparatus) according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Fig. 1 shows a screen printing apparatus 1 of the present invention. For ease of explanation, in this embodiment, the left-right direction of the screen printing apparatus 1 (direction perpendicular to the paper surface of Fig. 1) is defined as the X direction, and the front-rear direction (left-right direction on the paper surface) is defined as the Y direction. The up-down direction is defined as the Z direction.

[0014] The screen printing apparatus 1 is an apparatus for printing a paste Pst such as solder onto an electrode pattern (not shown) provided on a substrate KB, and includes a substrate holding unit 11 for holding the substrate KB, and a substrate holding unit movement mechanism 12 for moving the substrate holding unit 11 in the XYZ directions. A mask 13 is provided above the substrate holding unit 11, and a print head 14 is provided above the mask 13 so as to be freely movable.

[0015] 1, substrate holding unit 11 includes a support portion 15 and a pair of clampers 16. Substrate holding unit 11 supports (supports) the lower surface of substrate KB with support portion 15, and clamps and holds both ends of substrate KB supported by support portion 15 with clamps.

[0016] The substrate-holding-part moving mechanism 12 includes a horizontal moving part 12a that moves the substrate holding part 11 in a horizontal plane (XY plane) and a lifting part 12b that raises and lowers the substrate holding part 11. The substrate-holding-part moving mechanism 12 moves the substrate holding part 11, which holds the substrate KB, in the horizontal plane (XY plane) by the horizontal moving part 12a, and raises and lowers it by the lifting part 12b.

[0017] The mask 13 is made of a metal plate and has a rectangular shape extending along a horizontal plane (XY plane). The peripheral portion of the mask 13 is held by a rectangular mask frame 13W. The central portion of the mask 13 is provided with pattern openings (not shown) that are arranged in accordance with the arrangement of the electrode pattern of the substrate KB.

[0018] 1 and 2, the print head 14 extends in the X direction, and is moved in the Y direction by a print head moving mechanism 14M consisting of a ball screw mechanism or the like. The print head 14 is equipped with two squeegees 14S arranged opposite each other in the Y direction. Each squeegee 14S has a spatula shape that extends in the X direction. The two squeegees 14S can be raised and lowered independently of the print head 14.

[0019] 1 and 2, a scraper unit 17 is connected to the print head 14. As described below, the scraper unit 17 repeatedly performs a paste transfer operation of recovering the paste Pst on the mask 13 and then transferring (i.e., transferring) the paste Pst onto the next mask 13 that is installed.

[0020] First, the configuration of the scraper unit 17 will be described. In Fig. 2, the scraper unit 17 comprises a unit base 21 extending horizontally from the print head 14, a lift cylinder 22 provided on the unit base 21, a scraper holder 23 raised and lowered by the lift cylinder 22, and a scraper 24 held by the scraper holder 23. The scraper 24 has a base end 24K held by the scraper holder 23 and extends in a cantilevered manner with a tip 24T facing the squeegee 14S. The scraper 24 has an inclined shape that gradually descends from the base end 24K side toward the tip 24T side (Figs. 3(a) and (b)).

[0021] Because the unit base 21 is connected to the print head 14, when the print head 14 moves in the Y direction, the scraper unit 17 moves in the Y direction together with the print head 14. When the lifting cylinder 22 is operated to lift the scraper holder 23, the scraper 24 held by the scraper holder lifts and lowers relative to the unit base 21.

[0022] 2 and 3(a) and (b), the upper surface of scraper 24 (specifically, a certain area of ​​the upper surface of scraper 24 including tip 24T) serves as paste collecting surface 24M. Paste collecting surface 24M is covered with sheet member 25.

[0023] The sheet member 25 is made of, for example, a vinyl tape-like material. In this embodiment, the sheet member 25 extends from the upper surface of the scraper 24 (i.e., the paste collecting surface 24M) to the lower surface of the scraper 24, with one end (the end extending along the upper surface of the scraper 24) held by the delivery reel 26a and the other end (the end extending along the lower surface of the scraper 24) held by the take-up reel 26b (FIGS. 2 and 3(a) and (b)).

[0024] 2 and 3(a) and (b), the delivery reel 26a and the take-up reel 26b are attached to the scraper holder 23, and a tension pulley 27 is attached to the scraper holder 23 at a lower position between the delivery reel 26a and the take-up reel 26b. The tension pulley 27 biases the portion of the sheet member 25 between the delivery reel 26a and the tip 24T of the scraper 24 toward the base end 24K of the scraper 24, so that the sheet member 25 is extended along the paste collecting surface 24M.

[0025] When the delivery reel 26a and the take-up reel 26b are moved in the same direction, the portion of the sheet member 25 that covers the paste collecting surface 24M of the scraper 24 moves up and down along the paste collecting surface 24M. In this embodiment, when the delivery reel 26a is rotated in the counterclockwise direction (arrow R1 shown in FIG. 3(b)) in FIG. 3(a) and (b) and the take-up reel 26b is rotated in the clockwise direction (arrow R2 shown in FIG. 3(b)) in FIG. 3(a) and (b), the delivery reel 26a delivers the sheet member 25 while the take-up reel 26b takes up the sheet member 25, so that the sheet member 25 descends along the paste collecting surface 24M (arrow S shown in FIG. 3(b)).

[0026] The rotation direction of the delivery reel 26a and the take-up reel 26b in the direction in which the sheet member 25 descends along the paste collecting surface 24M is hereinafter referred to as the "forward direction." Conversely, the rotation direction of the delivery reel 26a and the take-up reel 26b in the direction in which the sheet member 25 ascends along the paste collecting surface 24M is hereinafter referred to as the "reverse direction."

[0027] When the delivery reel 26a and the take-up reel 26b are rotated in the forward direction as described above to lower the sheet member 25 along the paste recovery surface 24M, the region RY1 of the sheet member 25 that covered the paste recovery surface 24M is sent to the lower surface side of the scraper 24, and a new region RY2 of the sheet member 25 is sent to the paste recovery surface 24M from the base end 24K side of the scraper 24 (FIG. 3(a)→FIG. 3(b)). As a result, the portion of the sheet member 25 that covers the paste recovery surface 24M is replaced by the region RY2 of the sheet member 25 from the region RY1, and the sheet member 25 covering the paste recovery surface 24M is in a renewed state. Hereinafter, the renewal of the sheet member 25 that covers the paste recovery surface 24M of the scraper 24 will be referred to as "renewal of the sheet member 25."

[0028] In this manner, in this embodiment, the delivery reel 26a and the take-up reel 26b form a sheet member updating section 26 that updates the portion of the sheet member 25 that covers the paste collecting surface 24M.

[0029] Fig. 4 shows a control system of the screen printing apparatus 1. In Fig. 4, a control unit 31 provided in the screen printing apparatus 1 controls the operation of supporting the substrate KB by the supporting unit 15 of the substrate holding unit 11, the operation of clamping the substrate KB by the clamper 16, and the operation of moving the substrate holding unit 11 in the X, Y and Z directions by the horizontal moving unit 12a and the lifting unit 12b of the substrate holding unit moving mechanism 12. The control unit 31 also controls the lifting and lowering operation of the squeegee 14S provided in the print head 14, and the operation of moving the print head 14 by the print head moving mechanism 14M. The control unit 31 also controls the rotation of the delivery reel 26a and take-up reel 26b provided in the scraper unit 17.

[0030] When the screen printing apparatus 1 performs a screen printing operation, first, the paste Pst is supplied onto the upper surface of the mask 13. This supply of the paste Pst differs from the case where the paste Pst is supplied by a paste supplying operation performed by the scraper unit 17, which will be described later, in that new paste Pst is supplied onto the mask 13.

[0031] Examples of cases where new paste Pst is supplied onto the mask 13 include the start of the first screen printing operation of the day, or the start of the first screen printing operation after the type of substrate KB is changed. Other examples include after the paste Pst supplied onto the mask 13 is left for a certain period of time and the paste Pst is removed due to deterioration in quality, or immediately after the mask 13 is replaced. Such supply of new paste Pst onto the mask 13 is performed manually by an operator or by a paste supplying device (not shown) provided in the screen printing apparatus 1.

[0032] Once new paste Pst has been supplied onto the mask 13 as described above, the screen printing apparatus 1 executes a printing operation. The printing operation is performed by lowering one of the two squeegees 14S provided on the print head 14 so that its lower end comes into contact with the upper surface of the mask 13, and in this state, moving the print head 14 in the Y direction by the print head moving mechanism 14M (arrow A shown in FIG. 1). Through this printing operation, the paste Pst on the mask 13 is scraped up by the squeegee 14S, and the paste Pst is applied to the electrode pattern through the pattern openings of the mask 13.

[0033] After performing the printing operation of the above procedure on a plurality of substrates KB, if it becomes necessary to change the type of substrate KB, the screen printing apparatus 1 performs an operation of changing the mask 13 in accordance with the type of substrate KB. During this operation of changing the mask 13, the screen printing apparatus 1 moves the scraper 24 (directly, the scraper unit 17) and places and collects the paste Pst on the current mask 13 (first mask) on the sheet member 25 covering the paste collecting surface 24M of the scraper 24, and then causes the scraper unit 17 to execute a paste transfer operation of lowering and supplying the collected paste Pst onto the next mask 13 (a second mask that is a different mask 13 from the first mask) after the replacement.

[0034] In the paste transfer operation, first, the paste Pst on the current mask 13 (first mask) is collected. In the paste Pst collection operation, first, the lift cylinder 22 is operated to lower the scraper holder 23 (arrow B1 shown in FIG. 5(a)), and the lower surface of the scraper 24 (more specifically, the sheet member 25 located on the lower surface side of the scraper 24) is brought into contact with the mask 13. At this time, the tip 24T of the scraper 24 is positioned near the paste Pst to be collected (FIG. 5(a)).

[0035] When the lower surface of the scraper 24 abuts against the mask 13, the delivery reel 26a is stopped and the take-up reel 26b is rotated in the reverse direction (arrow R3 shown in FIG. 6(a)), thereby unwinding and loosening a predetermined length of the sheet member 25 below the scraper 24 (FIG. 6(a)). The length of the sheet member 25 unwound here is the amount of movement toward the upper side (base end 24K side) of the sheet member 25 on the paste recovery surface 24M side by the next rotation of the delivery reel 26a in the reverse direction. When the predetermined length of the sheet member 25 has been unwound from the take-up reel 26b, the rotation of the take-up reel 26b is stopped.

[0036] When a predetermined length of the sheet member 25 below the scraper 24 has been unwound by rotating the take-up reel 26b in the reverse direction, the screen printing apparatus 1 operates the print head moving mechanism 14M to move the print head 14 (i.e., the scraper unit 17) in a direction (the forward direction, indicated by the arrow C1 in FIG. 6(b)) in which the tip 24T of the scraper 24 approaches the paste Pst on the mask 13. As a result, the tip 24T of the scraper 24 approaches the paste Pst on the mask 13 while sliding over the mask 13.

[0037] When the tip 24T of the scraper 24 approaches the paste Pst on the mask 13 and enters the paste Pst (FIG. 6(b)), the delivery reel 26a is rotated in the reverse direction (arrow R4 shown in FIG. 6(c)) without rotating the take-up reel 26b. As a result, the paste Pst on the mask 13 moves together with the sheet member 25 moving upward along the upper surface of the scraper 24, and rides up onto the paste recovery surface 24M of the scraper 24 (more specifically, onto the sheet member 25 covering the paste recovery surface 24M) (arrow D shown in FIGS. 6(b) and (c)).

[0038] At this time, the sheet member 25 that the delivery reel 26a pulls up along the paste collecting surface 24M of the scraper 24 corresponds to the sheet member 25 that has been slackened on the lower surface side of the scraper 24. Therefore, the load torque that the delivery reel 26a receives when the delivery reel 26a pulls up the sheet member 25 is extremely small.

[0039] As described above, by rotating the delivery reel 26a in the reverse direction, the paste Pst on the mask 13 moves to the paste recovery surface 24M of the scraper 24, the sheet member 25 on the lower surface side of the scraper 24 becomes loose, and when the paste Pst on the mask 13 rides up onto the paste recovery surface 24M of the scraper 24 (FIG. 5(b)), the rotation of the delivery reel 26a is stopped. Then, the lift cylinder 22 is operated to lift the unit base 21 (arrow B2 shown in FIG. 5(c)). This ends the paste recovery operation by the scraper unit 17.

[0040] After the paste Pst recovery operation is completed, a new next mask 13 (second mask) is installed and the replacement work of the mask 13 is completed, the screen printing apparatus 1 causes the scraper unit 17 to perform a paste supply operation. In the paste supply operation, first, the print head 14 (i.e., the scraper unit 17) is moved by the print head moving mechanism 14M to position the scraper unit 17 above the new mask 13 after replacement. At this time, the scraper unit 17 is positioned so that the paste Pst recovered in the paste recovery operation is located above the supply location of the paste Pst in the new mask 13 after replacement.

[0041] Once the scraper unit 17 is positioned above the new mask 13, the lift cylinder 22 is operated to lower the unit base 21 (arrow B1 shown in FIG. 7(a)) and bring the tip 24T of the scraper 24 into contact with the new mask 13 (FIG. 7(a)). Once the tip 24T of the scraper 24 has come into contact with the new mask 13, the control unit 31 operates the print head moving mechanism 14M to move the print head 14 (i.e., the scraper unit 17) in a direction in which the tip 24T of the scraper 24 moves away from the paste Pst (returning direction; arrow C2 shown in FIG. 7(b)). Then, while continuing to move the print head 14, the supply reel 26a and the take-up reel 26b are rotated synchronously in the forward direction (arrows R1 and R2 shown in Figure 7(b)), and the sheet member 25 covering the paste recovery surface 24M is moved (descended) toward the tip 24T of the scraper 24 (arrow S shown in Figure 7(b)).

[0042] As the print head 14 is moved backward and the sheet member 25 covering the paste collection surface 24M is lowered, the paste Pst that had climbed up onto the paste collection surface 24M of the scraper 24 is lowered onto the mask 13 (second mask) (FIG. 7(c)). Once the paste Pst has been lowered onto the mask 13 (second mask), the rotation of the delivery reel 26a and the take-up reel 26b is stopped. This ends the paste supply operation (and therefore the paste transfer operation).

[0043] In the above paste supply operation, the length of the sheet member 25 that is unwound by the delivery reel 26a and wound by the take-up reel 26b is the length of the sheet member 25 unwound by the take-up reel 26b at the beginning of the paste recovery operation (the length of the region RY1) in this embodiment. As a result, the position of the region RY1 on the upper surface of the scraper 24 after the paste supply operation is completed is substantially the same as the position of the region RY1 on the upper surface of the scraper 24 before the paste recovery operation is started. Therefore, there is no change in the position of the sheet member 25 with respect to the upper surface of the scraper 24 before and after the paste transfer operation (FIG. 6(a)→FIG. 6(b)→FIG. 6(c)→FIG. 7(a)→FIG. 7(b)→FIG. 7(c)), and the sheet member 25 is not updated by the paste transfer operation.

[0044] When the paste transfer operation is completed, the screen printing apparatus 1 repeats the screen printing operation using the new mask 13 (second mask) to which the paste Pst has been transferred from the old mask 13 (first mask). Then, when it becomes necessary to replace the mask 13 next time, the screen printing apparatus 1 updates the sheet member 25 in the manner described above (FIG. 3(a)→FIG. 3(b)), or, if a predetermined condition is satisfied, causes the scraper unit 17 to perform the paste transfer operation without updating the sheet member 25.

[0045] Here, the reason why the sheet member 25 is replaced before executing the paste transfer operation as described above is to prevent the paste Pst adhering to the sheet member 25 in the previous paste transfer operation from being mixed with the paste Pst to be transferred next (mixing of the new and old paste Pst) and to prevent deterioration in the quality of the paste Pst. In order to prevent such mixing of the new and old paste Pst, it is sufficient to always update the sheet member 25 after the scraper unit 17 finishes the paste transfer operation.

[0046] However, even if the sheet member 25 is not necessarily renewed after the paste transfer operation is completed as described above, there are cases in which mixing of the new and old pastes Pst is acceptable depending on the conditions (i.e., it is considered that the quality of the paste Pst does not deteriorate even if the new and old pastes Pst are mixed). In this embodiment, in addition to a mode (called "normal mode") in which the sheet member 25 is necessarily renewed before the paste transfer operation is performed, a mode (called "saving mode") is provided in which, while the sheet member 25 is renewed before the paste transfer operation is performed as a rule, the renewal of the sheet member 25 is omitted when a certain condition is satisfied, thereby saving the sheet member 25, and one of these two modes can be selected arbitrarily. The following will explain this mode.

[0047] 4, the control unit 31 includes a storage unit 32, a counter 33, a timer 34, and a determination unit 35. To the control unit 31, a mode selection unit 36 ​​is connected.

[0048] The storage unit 32 stores information about the paste Pst in addition to the execution program for the screen printing work executed by the screen printing apparatus 1. The information about the paste Pst here refers to information such as the type of paste Pst that is written in the execution program for the screen printing work and that changes as the screen printing work progresses.

[0049] The counter 33 functions as a counting unit that counts the number of times (referred to as the "number of consecutive collections") that the paste Pst has been continuously collected by the paste collection surface 24M without the delivery reel 26a and the take-up reel 26b (i.e., the sheet member renewal unit 26) performing the renewal operation of the sheet member 25. The timer 34 functions as a timing unit that measures the elapsed time (referred to as the "left-standing time") since the paste Pst to be collected, i.e., the paste Pst supplied to the current mask 13 (first mask), has been left alone (since it has become unused).

[0050] When it is determined that the mask 13 needs to be replaced, the determination unit 35 determines whether the type of paste Pst used before and after the replacement of the mask 13 is the same. When it is determined that the type of paste Pst used before and after the replacement of the mask 13 is the same (but if a saving mode, which will be described later, has been selected), it then determines whether or not predetermined conditions (two conditions) are satisfied. In this embodiment, one of the two conditions (the first condition) is that "the number of consecutive collections counted by the counter 33 is less than a predetermined number of times," and the other of the two conditions (the second condition) is that "the leaving time measured by the timer 34 is shorter than a predetermined time."

[0051] When judging whether the type of paste Pst used before and after replacement of the mask 13 is the same, the judgment unit 35 compares the type of paste Pst used in the mask 13 before replacement with the type of paste Pst to be used in the mask 13 after replacement based on the information stored in the memory unit 32. Then, when it is detected that the type of paste Pst used in the mask 13 before replacement is the same as the type of paste Pst to be used in the mask 13 after replacement, it judges that the type of paste Pst used before and after replacement of the mask 13 is the same.

[0052] When determining whether the first condition is satisfied, the determination unit 35 compares the number of consecutive collections counted by the counter 33 with a predetermined number (e.g., 3 times). If the determination unit 35 detects that the number of consecutive collections is less than the predetermined number, it determines that the first condition is satisfied.

[0053] Furthermore, when judging whether the second condition is satisfied, the judgment unit 35 compares the left-standing time measured by the timer 34 with a predetermined time (e.g., 20 minutes). If it detects that the left-standing time is shorter than the predetermined time, it judges that the second condition is satisfied.

[0054] When the judgment unit 35 judges that both of the above two conditions are satisfied, that is, when it detects that the counted number of consecutive collections is less than the predetermined number and detects that the measured time of leaving is shorter than the predetermined time, it judges that all the predetermined conditions are satisfied. On the other hand, when it judges that either one of the two conditions is not satisfied, it judges that the predetermined conditions are not satisfied.

[0055] The mode selection unit 36 ​​is composed of, for example, buttons displayed on a screen of a touch panel (not shown) provided in the screen printing apparatus 1. The mode selection unit 36 ​​can select either a "normal mode" or a "saving mode." When the "normal mode" is selected from the mode selection unit 36, the control unit 31 enters the normal mode, and when the "saving mode" is selected from the mode selection unit 36, the control unit 31 enters the saving mode.

[0056] When the normal mode is selected by the mode selection unit 36, the control unit 31 always causes the sheet material updating unit 26 to perform an update operation of the sheet material 25 before executing the paste transfer operation. When the saving mode is selected by the mode selection unit 36, the control unit 31 causes the sheet material updating unit 26 to perform an update operation of the sheet material 25 in principle before executing the paste transfer operation, but does not cause the sheet material updating unit 26 to perform an update operation of the sheet material 25 when it is determined that a predetermined condition is satisfied.

[0057] The flowchart of FIG. 8 shows the flow of the screen printing operation by the screen printing apparatus 1 in this embodiment. As shown in this flowchart, when the screen printing apparatus 1 is performing a printing operation (step ST1) and it becomes necessary to replace the mask 13 (step ST2), the control unit 31 (determination unit 35) determines whether the type of paste Pst used before and after the replacement of the mask 13 is the same or not based on the information stored in the storage unit 32 (step ST3). If it is determined that the type of paste Pst is not the same, the mask 13 is replaced together with the paste Pst (step ST4), and the process returns to step ST1 after waiting for the paste Pst to be newly supplied to the newly installed mask 13 (step ST5). Then, the printing operation is performed using the (newly installed) mask 13 replaced in step ST4 and the paste Pst newly supplied in step ST5.

[0058] On the other hand, if the control unit 31 determines in step ST3 that the type of paste Pst used before and after replacement of the mask 13 is the same, it determines whether the mode currently selected by the mode selection unit 36 ​​is the normal mode or the saving mode (step ST6). If the control unit 31 determines in step ST6 that the currently selected mode is the normal mode, it causes the sheet member updating unit 26 to update the sheet member 25 (step ST7) and then causes the scraper unit 17 to perform a paste recovery operation (step ST8).

[0059] After step ST8, when the mask 13 is replaced with a new mask 13 (step ST9), the control unit 31 causes the scraper unit 17 to perform a paste supply operation (step ST10). After causing the scraper unit 17 to execute a paste transfer operation, the process returns to step ST1, and a printing operation is performed using the replaced (newly installed) mask 13 in step ST9 and the paste Pst (paste Pst transferred from the previous mask 13) supplied in step ST10.

[0060] On the other hand, if the control unit 31 determines in step ST6 that the currently selected mode is the saving mode, it checks whether the number of consecutive recoveries counted by the counter (the number of times that paste Pst was consecutively recovered by the paste recovery surface 24M without the sheet material 25 being updated by the sheet material updating unit 26) is smaller than a predetermined number (step ST11).

[0061] When the control unit 31 detects in step ST11 that the number of continuous collections is less than a predetermined number, it then checks whether the left-standing time (the time elapsed since the paste Pst to be collected was left standing) measured by the timer 34 is shorter than a predetermined time (step ST12). As a result, when it detects that the left-standing time measured by the timer 34 is shorter than the predetermined time, it causes the scraper unit 17 to perform a paste collection operation (step ST8) without causing the sheet member renewal unit 26 to perform a renewal operation of the sheet member 25. Then, when the mask 13 is replaced with a new mask 13 (step ST9), it causes the scraper unit 17 to perform a paste supply operation (step ST10), and returns to step ST1 to perform a printing operation.

[0062] In response to this, when the control unit 31 detects in step ST11 that the number of continuous collections is greater than the predetermined number of times, and when the control unit 31 detects in step ST12 that the standing time is longer than the predetermined time, it causes the sheet member renewal unit 26 to perform a renewal operation of the sheet member 25 (step ST7). Then, it causes the scraper unit 17 to perform a paste recovery operation (step ST8), and when the mask 13 is replaced with a new mask 13 (step ST9), it causes the scraper unit 17 to perform a paste supply operation (step ST10), and returns to step ST1.

[0063] In this way, in the screen printing operation performed by the screen printing apparatus 1, a printing process (step ST1) for performing screen printing on the substrate KB is repeatedly performed, and when the mask 13 is replaced, the paste Pst on the current mask 13 (first mask) is loaded onto the paste recovery surface 24M of the scraper 24 and recovered, and then a paste transfer process (steps ST8 to ST10) is performed in which the recovered paste Pst is lowered and supplied onto the next mask 13 (second mask).

[0064] When the normal mode is selected, the paste transfer process is always performed after the sheet member 25 is updated, but when the saving mode is selected, the paste transfer process is performed after the sheet member 25 is updated only when a predetermined condition is not satisfied. In other words, when the saving mode is selected, the paste transfer process is performed without updating the sheet member 25, provided that a predetermined condition is satisfied, so that wear of the sheet member 25 is suppressed.

[0065] The paste transfer device in this embodiment is a device that performs a paste transfer operation in which the paste Pst on the current mask 13 (first mask) is placed on a sheet member 25 covering the upper surface (paste recovery surface 24M) of a movable scraper 24, and then the recovered paste Pst is lowered and supplied onto a next mask 13 (second mask) different from the first mask, and is included in the above-mentioned screen printing device 1.In other words, the paste transfer device is equipped with a sheet member renewal unit 26 that renews the portion covering the paste recovery surface 24M of the sheet member 25, and a control unit 31 that controls the paste transfer operation and the renewal operation of the sheet member 25 by the sheet member renewal unit 26.Before performing the paste transfer operation, the control unit 31 determines whether a predetermined condition is satisfied, and controls the paste transfer operation by the scraper 24 and the renewal operation of the sheet member 25 by the sheet member renewal unit 26 based on the determination result. In detail, when the control unit 31 determines that the above-mentioned specified conditions are satisfied, it executes the paste transfer operation without causing the sheet material updating unit 26 to perform the update operation of the sheet material 25, and when it determines that the specified conditions are not satisfied (even a part of the multiple conditions are not satisfied), it causes the sheet material updating unit 26 to perform the update operation of the sheet material 25 and then executes the paste transfer operation.

[0066] The paste transfer method by the paste transfer device is a method of carrying out a paste transfer process (steps ST8 to ST10) in which the paste Pst on the current mask 13 (first mask) is placed and collected on the sheet member 25 covering the upper surface (paste collecting surface 24M) of the movable scraper 24, and then the collected paste Pst is lowered and supplied onto the next mask 13 (second mask) different from the first mask. In this paste transfer method, before carrying out the paste transfer process, it is determined whether or not a predetermined condition is satisfied (steps ST11 and ST12), and if it is determined that the predetermined condition is satisfied, the paste transfer process is carried out without replacing the sheet member 25, and if it is determined that the predetermined condition is not satisfied, the sheet member 25 is replaced (step ST7) before carrying out the paste transfer operation.

[0067] In the paste transfer device (paste transfer method) of this embodiment, the sheet member 25 is not necessarily renewed before the paste transfer operation is performed, but when it is determined that a predetermined condition is satisfied, the paste transfer operation is performed without renewing the sheet member, so that wear of the sheet member 25 can be suppressed compared to when the sheet member 25 is necessarily renewed before the paste transfer operation is performed. This also reduces the frequency of the sheet member replacement work, so that the productivity of the work (screen printing work) by the screen printing device 1 can be improved.

[0068] Furthermore, the screen printing apparatus 1 in this embodiment performs a printing operation of applying paste Pst to the substrate KB through the mask 13, but the paste transfer apparatus (paste transfer method) in this embodiment allows the operation to be continued while transferring the paste Pst from one mask 13 (first mask) to the next mask 13 (second mask), making it possible to operate in a cost-effective manner without wasting the paste Pst and while saving on the sheet material 25.

[0069] As described above, in the screen printing apparatus 1 (paste transfer apparatus, paste transfer method) of this embodiment, when predetermined conditions are satisfied, the paste transfer operation is performed without replacing the sheet member, thereby suppressing wear on the sheet member 25. This reduces the frequency of sheet member replacement work and improves the productivity of work (screen printing work) performed by the screen printing apparatus 1.

[0070] Although the embodiment of the present invention has been described so far, the present invention is not limited to the above, and various modifications are possible. For example, the sheet member renewing unit 26 shown in the above embodiment is configured to include the delivery reel 26a and the take-up reel 26b, but the sheet member renewing unit 26 may have another configuration as long as it can renew the portion covering the paste collecting surface 24M of the sheet member 25. In addition, in the above embodiment, the configuration allows the selection of either the normal mode or the saving mode, but such a mode selection may not be possible, and only the operation corresponding to the saving mode may be performed at all times.

[0071] Furthermore, the manner in which the sheet member 25 is moved relative to the paste recovery surface 24M in the above-mentioned paste transfer operations (paste recovery operation and paste supply operation) is one example, and in the paste recovery operation, the paste Pst on the mask 13 can be made to ride up onto the paste recovery surface 24M of the scraper 24, and in the paste supply operation, the manner in which the sheet member 25 is moved is not limited as long as the paste Pst that has been made to ride up onto the paste recovery surface 24M can be lowered onto the mask 13. [Industrial Applicability]

[0072] A paste transfer device, a screen printing device, and a paste transfer method are provided that are capable of suppressing wear of sheet members and improving the productivity of screen printing work. [Explanation of symbols]

[0073] 1 Screen printing equipment 11 Board holding part 12 Board holder moving mechanism 12a Horizontal moving part 12b Lifting section 13 Mask (1st mask) (2nd mask) 14 Print Head 14S Squeegee 14M Print head movement mechanism 15 Lower support part 16 Clamper 17 Scraper unit 21 Unit Base 22 Lifting cylinder 23 Scraper holder 24 Scraper 24M Paste collection surface 25 Sheet material 26 Sheet material renewal section 26a Sending reel 26b Winding reel 27 Tension pulley 31 Control Unit 32 Storage section 33 Counter (counter section) 34 Timer (timing unit) KB board Pst paste

Claims

1. A paste transfer device that performs a paste transfer operation in which paste on a first mask is placed on a sheet member that covers a paste collecting surface of a movable scraper, the sheet member collects the paste, and then the collected paste is lowered onto a second mask that is different from the first mask and supplied, a sheet member updating unit that updates a portion of the sheet member that covers the paste collecting surface; a control unit for controlling the paste transfer operation and the sheet member updating operation by the sheet member updating unit, A paste transfer device in which the control unit determines whether or not predetermined conditions are satisfied before performing the paste transfer operation, and controls the paste transfer operation and the sheet member update operation by the sheet member update unit based on the determination result.

2. The paste transfer device of claim 1, wherein, when the control unit determines that the specified conditions are met, it performs the paste transfer operation without causing the sheet material updating unit to perform the sheet material updating operation, and when the control unit determines that the specified conditions are not met, it causes the sheet material updating unit to perform the sheet material updating operation and then performs the paste transfer operation.

3. A counting unit is further provided for counting the number of consecutive collections, which is the number of times that the paste is consecutively collected by the paste collecting surface without the sheet member updating operation being performed by the sheet member updating unit, 2. The paste transfer device according to claim 1, wherein the control unit determines that a part of the predetermined condition is satisfied when it detects that the number of consecutive recoveries counted by the counting unit is less than a predetermined number.

4. Further, a timer unit is provided for timing an elapsed time from when the paste to be collected is left standing, 2. The paste transfer device according to claim 1, wherein the control unit determines that a part of the predetermined condition is satisfied when the control unit detects that the leaving time measured by the timing unit is shorter than a predetermined time.

5. A paste transfer device that performs a paste transfer operation in which paste on a first mask is placed on a sheet member that covers a paste collecting surface of a movable scraper, the sheet member collects the paste, and then the collected paste is lowered onto a second mask that is different from the first mask and supplied, a sheet member updating unit that updates a portion of the sheet member that covers the paste collecting surface; a control unit that controls the paste transfer operation and the sheet member updating operation by the sheet member updating unit; A mode selection unit capable of selecting either a normal mode or a saving mode, A paste transfer device in which, when the normal mode is selected by the mode selection unit, the control unit causes the sheet material updating unit to perform an updating operation of the sheet material and then performs the paste transfer operation, and, when the saving mode is selected by the mode selection unit, the control unit determines whether a predetermined condition is satisfied before performing the paste transfer operation, and controls the paste transfer operation and the updating operation of the sheet material by the sheet material updating unit based on the determination result.

6. The paste transfer device of claim 5, wherein, when the control unit determines that the specified conditions are satisfied, it performs the paste transfer operation without causing the sheet material updating unit to perform the sheet material updating operation, and when the control unit determines that the specified conditions are not satisfied, it causes the sheet material updating unit to perform the sheet material updating operation and then performs the paste transfer operation.

7. A screen printing apparatus that performs a printing operation of applying paste to a substrate through a mask, the screen printing apparatus transferring paste from the first mask to the second mask using a paste transfer device according to any one of claims 1 to 6, and continuing the printing operation.

8. A paste transfer method for carrying out a paste transfer step of loading and recovering paste on a first mask on a sheet member covering a paste recovery surface of a movable scraper, and then lowering and supplying the recovered paste onto a second mask different from the first mask, comprising: A paste transfer method comprising: determining whether or not a predetermined condition is satisfied before executing the paste transfer process; and if it is determined that the predetermined condition is satisfied, executing the paste transfer process without updating the sheet member; and if it is determined that the predetermined condition is not satisfied, updating the sheet member and then executing the paste transfer process.

Images