Printing device

Abstract

To reduce occurrence of poor printing.SOLUTION: A printing device, which is configured to print viscose fluid on a printing object by moving the viscose fluid on a screen mask having an opening in a printing direction using a squeegee, comprises: a lifting part that moves the squeegee up and down; a moving part that moves the squeegee in the printing direction; a printing control part that executes printing processing for controlling the lifting part and the moving part so that the squeegee moves from a starting position closer to an upstream side in the printing direction than the viscose fluid on the screen mask across the opening to an ending position at a downstream side in the printing direction; and a printing-start control part that starts to move the squeegee acceleratingly at the starting position and then controls the lifting part and the moving part so that the squeegee is accelerated again to start the printing processing, after the squeegee is decelerated or stops just before the viscose fluid.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] SUMMARY Disclosed herein is a printing device. [Background technology]

[0002] Conventionally, there has been proposed a screen printer that prints cream solder on a substrate by horizontally moving a squeegee from a position in front of the cream solder on a screen mask having through holes (see Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2008-119851 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the above-mentioned screen printing machine, the printing time can be shortened by increasing the moving speed of the squeegee, but when the moving speed of the squeegee is increased, the squeegee may be deformed by a reaction force when it comes into contact with the cream solder from a distant position, or the squeegee may lift up, creating a gap between the squeegee and the screen mask. If printing is performed with a deformed or lifted squeegee, the cream solder may not be pushed into the through holes with sufficient pressure, or some of the cream solder may not be scraped off, resulting in poor printing.

[0005] The main object of the present disclosure is to reduce the occurrence of printing defects by suppressing deformation and lifting of the squeegee at the start of printing. [Means for solving the problem]

[0006] The printing device of the present disclosure employs the following means to achieve the above-mentioned main object.

[0007] The printing device of the present disclosure is A printing device that prints a viscous fluid on a printing target by moving a viscous fluid on a screen mask having an opening in a printing direction with a squeegee, A lifting unit that lifts and lowers the squeegee; A moving unit that moves the squeegee in a printing direction; a print control unit that executes a printing process to control the lifting unit and the moving unit so that the squeegee moves from a start position away from the viscous fluid on the screen mask on the upstream side in the printing direction to an end position on the downstream side in the printing direction across the opening; a print start control unit that starts the movement of the squeegee by accelerating from the start position, and controls the lifting unit and the moving unit so that the squeegee decelerates or stops just before the viscous fluid and then accelerates again, thereby starting the printing process; The gist of the invention is to provide the following:

[0008] The printing device of the present disclosure slows down or stops the squeegee just before the viscous fluid, so that the speed at which the squeegee comes into contact with the viscous fluid can be reduced. This reduces the reaction force acting on the squeegee, making it possible to suppress deformation of the squeegee and lifting of the squeegee. Then, the squeegee is re-accelerated after that, so that printing can be performed at a high printing speed. This makes it possible to suppress deformation of the squeegee and lifting of the squeegee at the start of printing, and reduce the occurrence of printing defects. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is an external view of a production system 10 including a screen printing machine 11. [Diagram 2] FIG. 2 is a schematic configuration diagram of a screen printing machine 11. [Diagram 3] FIG. 2 is a schematic diagram of a screen mask 70. [Figure 4] 2 is a block diagram showing electrical connections in the production system 10. FIG. [Diagram 5] 10 is a flowchart illustrating an example of a printing process. [Figure 6] FIG. 13 is an explanatory diagram showing how a solder width δ is measured. [Figure 7] FIG. 13 is an explanatory diagram showing a method for measuring a solder width δ based on a height measurement result. [Figure 8] 11 is an explanatory diagram showing a change in speed of a first squeegee 22a when forward printing is performed. FIG. [Figure 9] 13 is an explanatory diagram showing a change in speed of a second squeegee 22b when reverse printing is performed. FIG. [Figure 10] 13 is an explanatory diagram showing a change in speed of a first squeegee 22a when forward printing is performed in a modified example. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Next, an embodiment of the present disclosure will be described with reference to the drawings. Fig. 1 is an external view of a production system 10 including a screen printer 11. Fig. 2 is a schematic configuration diagram of the screen printer 11. Fig. 3 is a schematic configuration diagram of a screen mask 70. Fig. 4 is a block diagram showing electrical connections in the production system 10. In Figs. 1 and 2, the left-right direction is the X-axis direction (the direction perpendicular to the paper surface in Fig. 2), the front-rear direction is the Y-axis direction, and the up-down direction is the Z-axis direction.

[0011] The production system 10 prints solder on a board S and mounts components on the board S. As shown in FIG. 1, the production system 10 includes a screen printing machine 11, a print inspection machine (not shown), a component mounter 13, a mounting inspection machine (not shown), and a management device 100.

[0012] The screen printing machine 11 prints solder on the board S by moving (rolling) a solder roll R on a screen mask 70. The print inspection machine takes an image of the board S on which solder has been printed and inspects the printed state of the solder. The component mounter 13 mounts components on the board S on which solder has been printed. The mounting inspection machine takes an image of the board S on which components have been mounted and inspects the mounting state of the components. The management device 100 manages the entire production system 10. The screen printing machine 11 of this embodiment will be described in more detail below.

[0013] As shown in Figures 1 and 2, the screen printing machine 11 of this embodiment includes a base 12, a print head 20, a substrate transport device 30, a lifting mechanism 40, a solder supply unit 50, a support rail 75, a screen mask 70, and a control device 80.

[0014] 3, the screen mask 70 includes a rectangular support frame 72 and a thin plate-like screen 71 stretched over the support frame 72. Pattern holes 71o are formed in the screen 71, and blank areas 71m are formed in front of and behind the pattern holes 71o in the screen 71. The screen printing machine 11 applies (prints) solder to the substrate S below through the pattern holes 71o by moving (rolling) the solder roll R on the screen mask 70 from one blank area 71m to the other blank area 71m with the first squeegee 22a or the second squeegee 22b sandwiching the pattern holes 71o.

[0015] The print head 20 includes a head body 21, a first squeegee 22a, a second squeegee 22b, a first squeegee lifting unit 24a, a second squeegee lifting unit 24b, a height sensor 25, and a head moving mechanism 60. The first squeegee 22a and the second squeegee 22b are made of resin (e.g., urethane) and are formed in a thin plate shape extending in the left-right direction. The first squeegee 22a and the second squeegee 22b are supported by a first lifting shaft 23a and a second lifting shaft 23b so as to be aligned in the front-rear direction while being inclined so as to move away from each other as they go downward. The first squeegee lifting unit 24a has a first lifting shaft 23a that can be raised and lowered, and raises and lowers the first squeegee 22a by raising and lowering the first lifting shaft 23a. The second squeegee lifting section 24b has a second lifting shaft 23b, and lifts and lowers the second squeegee 22b by lifting and lowering the second lifting shaft 23b. The height sensor 25 is provided facing downward on the bottom of the head body 21. The height sensor 25 is a reflective laser displacement meter having a light projecting section that projects light downward and a light receiving section that receives reflected light. The height sensor 25 measures the vertical distance to the surface of the target object. The linear encoder 26 detects the linear displacement amount of the head body 21 in the front-rear direction.

[0016] The head moving mechanism 60 moves the head body 21 in the front-rear direction (printing direction). The head moving mechanism 60 has a motor 61, a ball screw shaft 62, a ball nut 63, and a driver 65. The head body 21 is supported movably with respect to a guide rail 90 extending in the front-rear direction. The ball nut 63 is fixed to the head body 21. The ball nut 63 is screwed into a ball screw shaft 62 extending in the front-rear direction. The ball screw shaft 62 is driven to rotate by the power of the motor 61. As a result, the head body 21 to which the ball nut 63 is fixed moves in the front-rear direction while being guided by the guide rail 90 by the drive of the motor 61. The driver 65 is a drive circuit for the motor 61.

[0017] The substrate transport device 30 transports the substrate S in the left-right direction. The substrate transport device 30 includes a support base 31, a pair of front and rear frames 32 provided on the support base 31, a transport conveyor 33 for transporting the substrate S, a substrate support section 34 for supporting the substrate S from below, a substrate lifting section 35 for raising and lowering the substrate support section 34, and a support plate 36 provided on the upper end of each frame 32. The transport conveyor 33 includes a drive roller and a driven roller provided on the left and right sides of the frame 32, and a transport belt stretched between the rollers, and transports the substrate S on the belt by driving the drive roller. The substrate support section 34 is raised by the substrate lifting section 35, and supports (clamps) the substrate S on the transport conveyor 33 by abutting it against the lower surface of the support plate 36.

[0018] The lifting mechanism 40 lifts and lowers the entire substrate transport device 30. The lifting mechanism 40 has a lifting platform 41, a motor 44, a ball screw shaft 45, and a ball nut 46. The lifting platform 41 supports the substrate transport device 30. The lifting platform 41 is supported movably with respect to a guide rail 43 extending in the vertical direction. The guide rail 43 is provided on the base 12. A ball nut 46 is attached to the lifting platform 41. The ball nut 46 is screwed into a ball screw shaft 45 extending in the vertical direction. The ball screw shaft 45 is driven to rotate by the power of a motor 44 fixed to the base 12. As a result, the lifting platform 41 to which the ball nut 46 is fixed moves in the vertical direction while being guided by the guide rail 43 by the drive of the motor 44.

[0019] The substrate transport device 30 is raised by the lifting mechanism 40, and the upper surface of the support plate 36 abuts against the lower surface of the screen 71, thereby supporting the screen 71 from below.

[0020] The solder supply unit 50 includes a cartridge 51 that contains solder paste, and supplies the solder paste from the cartridge 51 onto the screen mask 70. As shown in FIG. 2, the solder supply unit 50 is disposed in front of the print head 20, and includes a connecting portion 52 that can be connected to and disconnected from the print head 20 (head body 21). The solder supply unit 50 moves in the front-rear direction together with the head body 21 by a head moving mechanism 60 while connected to the head body 21 by the connecting portion 52. The solder supply unit 50 moves in the left-right direction by a drive unit (not shown). The drive unit includes, for example, a drive roller driven by a motor, a driven roller, and a belt stretched between the drive roller and the driven roller, and the solder supply unit 50 (cartridge 51) is fixed to the belt.

[0021] 2, the support rails 75 are a pair of left and right long rails that are installed in the middle section of the screen printing machine 11 and extend in the front-rear direction (Y-axis direction). The pair of left and right support rails 75 support two sides (left and right sides) of the screen mask 70 that are parallel to the printing direction from below.

[0022] The control device 80 is configured as a microprocessor having a CPU 81, a ROM 82, a RAM 83, a storage (e.g., an SSD or HDD) 84, etc. The control device 80 inputs a height signal from the height sensor 25. The control device 80 also outputs control signals to the board lifting section 35 of the board transport device 30, the motor 44 of the lifting mechanism 40, the solder supply unit 50, etc. The control device 80 also inputs a pulse signal from the linear encoder 26.

[0023] The management device 100 is configured as a microprocessor with a CPU at its core, and in addition to the CPU, includes a ROM for storing processing programs, a RAM for temporarily storing processing data, storage, a communication port, and the like. An input device 101 such as a mouse or keyboard, and a display device 102 such as a liquid crystal display are connected to the management device 100. Job information including a production schedule is stored in the storage. The production schedule includes the type of boards S to be produced, the planned number of boards S to be produced, and the like. The management device 100 also communicates with the control device 80 of the screen printing machine 11 and the control device of the component mounting machine 13 via the communication port, and exchanges various signals and data with the control device 80 of the screen printing machine 11 and the control device of the component mounting machine 13.

[0024] Next, the operation (printing process) of the screen printer 11 of the present embodiment thus configured will be described. FIG. 5 is a flow chart showing an example of the printing process. The printing process is executed by the CPU 81 of the control device 80 after inputting an instruction to start production from the management device 100. In the printing process, the CPU 81 alternately performs forward printing, in which the head body 21 is moved in the forward direction (direction from the front side to the rear side) while the first squeegee 22a is lowered and the second squeegee 22b is raised, to print solder on the board S, and reverse printing, in which the head body 21 is moved in the reverse direction (direction from the rear side to the front side) while the first squeegee 22a is raised and the second squeegee 22b is lowered, to print solder on the board S. In this embodiment, solder is printed on one board S in one way (either forward printing or reverse printing).

[0025] When the printing process is started, the CPU 81 first starts a printing preparation process (S100). The printing preparation process includes a carry-in process in which the board S is carried into the machine by the transport conveyor 33 of the board transport device 30, a clamping process in which the carried-in board S is clamped by the board lifting section 35, and a support process in which the board transport device 30 is raised by the lifting mechanism 40 and the screen 71 is supported by the support plate 36 of the board transport device 30. Next, the CPU 81 controls the motor 61 of the head moving mechanism 60 to move the head main body 21 so that the optical axis of the height sensor 25 crosses the solder roll R in the front-rear direction, as shown in Figs. 6(a) to 6(c), and acquires the height H from the height sensor 25 (S102).

[0026] Then, based on the height signal from the height sensor 25 and the pulse signal from the linear encoder 26, the CPU 81 measures the movement distance D of the head main body 21 from one end of the solder roll R to the other end, and sets the movement distance D to the solder width δ (S104). When the solder roll R is not on the optical axis of the height sensor 25 (see FIGS. 6(a) and 6(c)), the measured value of the height H is approximately constant (height H0) even if the head main body 21 moves (see FIG. 7), and when the solder roll R is present (see FIG. 6(b)), the measured value of the height H is smaller than the height H0. Therefore, by extracting this change, it is possible to detect one end and the other end of the solder roll R.

[0027] Next, the CPU 81 waits until the printing preparation is completed (all of the loading process, clamping process, and supporting process are completed) (S106). Next, the CPU 81 judges whether the printing mode is forward printing or not (S108). When the CPU 81 judges that the printing mode is forward printing, the CPU 81 sets a position that is a distance M away from the backward printing end position Pb2, which is the printing end position of the backward printing, in the backward direction as the temporary stop position Ps1, which is the position where the first squeegee 22a is temporarily stopped during forward printing (S110). The distance M is the solder width δ plus a margin β of about several [mm]. Since the backward printing end position Pb2 can be regarded as the position of the end of the solder roll R on the forward direction side, the temporary stop position Ps1 is set to a position that is a margin β away from the end of the solder roll R on the backward direction side in the backward direction, as shown in FIG. 8.

[0028] After setting the temporary stop position Ps1, the CPU 81 controls the motor 61 of the head moving mechanism 60 to move the first squeegee 22a to the forward printing start position Pa1, which is the printing start position for forward printing (S112). Here, the forward printing start position Pa1 is a position further toward the return direction side than the end of the solder roll R located in the margin portion 71m, as shown in Fig. 8, and is a predetermined position. Then, the CPU 81 controls the first squeegee lifting and lowering unit 24a to lower the first squeegee 22a (S114).

[0029] Next, the CPU 81 sets the temporary stop position Ps1 to the target position (S116). Then, the CPU 81 drives and controls the motor 61 by feedback control (PI control, etc.) so that the first squeegee 22a is located at the target position (S118). This process is executed as follows. That is, the CPU 81 calculates the target position of the head body 21 corresponding to the target position of the first squeegee 22a. Next, the CPU 81 calculates the target moving speed of the head body 21 with a predetermined speed as the upper limit by PI control based on the deviation between the target position of the head body 21 and the actual position of the head body 21 calculated by the pulse signal from the linear encoder 26, and calculates a current command value for moving the head body 21 at the target moving speed. Next, the CPU 81 generates a driving signal based on the deviation between the calculated current command value and the current value from a current sensor (not shown), and outputs it to the driver 65. The driver 65 supplies the driving current based on the driving signal to the motor 61 to drive the motor 61. Then, the CPU 81 waits until the first squeegee 22a reaches the target position (S120). Specifically, the CPU 81 waits until the actual position of the head main body 21 coincides with a position corresponding to the target position of the first squeegee 22a.

[0030] 8 shows how the movement speed of the first squeegee 22a changes when the processes of S118 and S120 are executed. When the deviation between the target position of the head body 21 and the actual position of the head body 21 is large, the target movement speed is set to a high speed, so the first squeegee 22a approaches the target position while accelerating. When the deviation between the target position of the head body 21 and the actual position of the head body 21 becomes small, the target movement speed is set to a low speed, so the first squeegee 22a approaches the target position while decelerating. When the deviation between the target position of the head body 21 and the actual position of the head body 21 disappears, the target movement speed is set to a value of 0, so the first squeegee 22a stops.

[0031] After the first squeegee 22a reaches the target position (pause position Ps1), the CPU 81 sets the forward printing end position Pb1, which is the printing end position of forward printing, as the target position (S122). Next, the CPU 81 controls the motor 61 by feedback control so that the first squeegee 22a is located at the target position (S124). Then, the CPU 81 waits until the first squeegee 22a reaches the target position (S126). The processes of S124 and S126 are the same as the processes of S118 and S120, except that the target position of the first squeegee 22a is the forward printing end position Pb1. The first squeegee 22a that has stopped at the pause position accelerates again and moves at a constant speed (predetermined speed), as shown in FIG. 8, and then decelerates again and stops at the target position (forward printing end position Pb1).

[0032] Next, the CPU 81 controls the first squeegee lifting unit 24a to lift the first squeegee 22a (S128). Next, the CPU 81 sets the print mode to return printing (S130). Then, the CPU 81 executes post-printing processing (S132) and ends the print processing. The post-printing processing includes a support release processing for releasing the support of the screen 71 by the support plate 36 of the substrate transport device 30, a clamp release processing for releasing the clamp of the substrate S by the substrate lifting unit 35, and a carry-out processing for carrying the substrate S downstream by the transport conveyor 33 of the substrate transport device 30.

[0033] When printing processing is performed on the next board S after the printing mode is set to reverse printing in S130, the printing mode is determined to be reverse printing in S108. In this case, the CPU 81 sets a position away from the forward printing end position Pb1 by a distance M in the forward direction as a temporary stop position Ps2 where the second squeegee 22b is temporarily stopped during reverse printing (S134). Since the forward printing end position Pb1 can be regarded as the position of the end of the solder roll R on the reverse direction side, the temporary stop position Ps2 is set to a position away from the end of the solder roll R on the forward direction side by a margin β, as shown in FIG.

[0034] Next, the CPU 81 moves the print head 20 to the return print start position Pa2, which is the position when the return print starts (S136). This process is the same as S112. Then, the CPU 81 controls the second squeegee lifting unit 24b to lower the second squeegee 22b (S138).

[0035] Next, the CPU 81 sets the temporary stop position Ps2 as the target position (S140). Then, the CPU 81 drives and controls the motor 61 by feedback control so that the second squeegee 22b is located at the target position (S142). Then, the CPU 81 waits until the second squeegee 22b reaches the target position (S144). The processes of S142 and S144 are the same as the processes of S118 and S120, except that the target position is set to the temporary stop position Ps2. Therefore, as shown in FIG. 9, the second squeegee 22b approaches the target position while accelerating, and then decelerates midway to stop at the target position (temporary stop position Ps2).

[0036] Next, the CPU 81 sets the backward print end position Pb2, which is the print end position of the backward print, as the target position (S146). Next, the CPU 81 drives and controls the motor 61 by feedback control so that the second squeegee 22b is located at the target position (S148). Then, the CPU 81 waits until the second squeegee 22b reaches the target position (S150). The processes of S148 and S150 are the same as the processes of S124 and S126 except that the target position is set to the backward print end position Pb2. Therefore, the second squeegee 22b, which has stopped at the temporary stop position Ps2, accelerates again, moves at a constant speed (predetermined speed), and decelerates again to stop at the target position (backward print end position Pb2), as shown in FIG. 9.

[0037] Next, the CPU 81 controls the second squeegee lifting unit 24b to lift the second squeegee 22b (S152). Then, the CPU 81 sets the print mode to forward printing (S154). Then, the CPU 81 executes post-printing processing (S132) and ends the print processing.

[0038] In forward printing, the CPU 81 temporarily stops the first squeegee 22a at a temporary stop position Ps1 in front of the solder roll R, and then accelerates it again to start printing. In return printing, the CPU 81 temporarily stops the second squeegee 22b at a temporary stop position Ps2 in front of the solder roll R, and then accelerates it again to start printing. This allows the speed at which the first squeegee 22a and the second squeegee 22b come into contact with the solder roll R to be lowered. This reduces the reaction force acting when the first squeegee 22a and the second squeegee 22b come into contact with the solder roll R, suppresses deformation of the first squeegee 22a and the second squeegee 22b, and reduces the occurrence of printing defects. In addition, the first squeegee 22a or the second squeegee 22b can be used to print solder on the board S at a relatively high printing speed.

[0039] Furthermore, in the printing process, the CPU 81 executes the solder width measurement process before the pre-printing process is completed. Therefore, compared to the case where the solder width measurement process is executed after the pre-printing process is completed, the solder can be printed on the board S more smoothly.

[0040] Furthermore, the CPU 81 measures the solder width δ of the solder roll R every time a printing process is performed, and sets the temporary stop positions Ps1, Ps2 based on the measurement results. Therefore, the head main body 21 can be temporarily stopped at an appropriate position (in front of the solder roll R) every time a printing process is performed.

[0041] Here, the correspondence between the main elements of this embodiment and the main elements of this disclosure described in the claims will be described. That is, the screen printing machine 11 of this embodiment corresponds to the printing device of this disclosure, the first squeegee lifting unit 24a and the second squeegee lifting unit 24b correspond to the lifting unit, the head moving mechanism 60 corresponds to the moving unit of this disclosure, the CPU 81 that executes the printing process corresponds to the printing processing unit of this disclosure, and the CPU 81 that executes the processes of S116 to S120 and S140 to S144 of the printing process corresponds to the print start control unit of this disclosure. Also, the height sensor 29 and the CPU 81 that executes the processes of S102 and S104 of the printing process correspond to the detection and estimation unit of this disclosure.

[0042] It goes without saying that the present disclosure is in no way limited to the above-described embodiment, and can be embodied in various forms as long as it falls within the technical scope of the present disclosure.

[0043] For example, in the above-described embodiment, the CPU 81 measures the movement distance D of the head main body 21 from one end to the other end of the solder roll R based on the height signal from the height sensor 25 and the pulse signal from the linear encoder 26, and sets the measured distance D as the solder width δ. The CPU 81 then sets the position that is a distance M that is the solder width δ plus a margin β in the backward direction from the backward print end position Pb2 as the temporary stop position Ps1. The CPU 81 also sets the position that is a distance M that is the solder width δ plus a margin β in the forward direction from the forward print end position Pb1 as the temporary stop position Ps2. However, the CPU 81 may calculate the position of the head main body 21 when the optical axis of the height sensor 25 passes the end of the solder roll R on the backward side based on the pulse signal from the linear encoder 26, and set the position that is a margin β away from the calculated position in the backward direction as the temporary stop position Ps1. In addition, the CPU 81 may calculate the position of the head body 21 when the optical axis of the height sensor 25 passes the end of the solder roll R on the forward side based on the pulse signal of the linear encoder 26, and set a position away from that position in the forward direction by a margin β as the temporary stop position Ps2.

[0044] In the above-described embodiment, the CPU 81 may count the number of printings and estimate the solder width δ based on the number of printings. In this case, the CPU 81 may measure the initial solder width δ0 of the solder roll R using a method similar to that of the above-described embodiment, and estimate the solder width δ by subtracting the initial solder width δ0 from the number of printings.

[0045] In the embodiment described above, the CPU 81 starts measuring the solder width δ and completes the measurement of the solder width δ between the start and end of the print preparation process. However, the CPU 81 may start measuring the solder width δ after forward printing or reverse printing is completed, and complete the measurement of the solder width δ by the time the print preparation process for the next print process is completed.

[0046] In the above-described embodiment, the head moving mechanism 60 moves the head body 21 in the front-rear direction by the motor 61, the ball screw shaft 62, and the ball nut 63. However, the head moving mechanism 60 may also move the head body 21 in the front-rear direction by a linear motor. In that case, the head 21 body may be attached to a mover of the linear motor.

[0047] In the above-described embodiment, solder is printed on one board S in one direction (either forward printing or reverse printing). Solder may be printed on one board S in both directions (both forward printing and reverse printing).

[0048] In the above-described embodiment, the CPU 81 stops the first squeegee 22a at the pause position Ps1 when performing forward printing. However, as shown in FIG. 10, the CPU 81 may move the first squeegee 22a to the pause position Ps1 while decelerating without stopping the first squeegee 22a, and then re-accelerate the first squeegee 22a. In this case, when performing forward printing, the CPU 81 sets, as a target position, a position that is separated from the pause position Ps1 by a distance γ of several [mm] to several [cm] in the forward direction in S116 of the printing process, and may switch the target position to the forward printing end position Pb1 when the first squeegee 22a reaches the pause position Ps1 in S120. Alternatively, the CPU 81 may define a lower limit speed greater than 0 for the target moving speed set by feedback control in S118 of the printing process. However, such a target speed is defined in S118, and it is not necessary to define such a target speed in S124. Also, when performing reverse printing, the CPU 81 stops the second squeegee 22b at the pause position Ps2. However, when performing reverse printing, the CPU 81 sets, as a target position, a position that is separated from the pause position Ps2 by a distance γ in the reverse direction in S140 of the printing process, and may switch the target position to the reverse printing end position Pb2 when the second squeegee 22b reaches the pause position Ps2 in S144. Alternatively, the CPU 81 may define a lower limit speed greater than 0 for the target moving speed set by feedback control in S142 of the printing process. However, such a target speed is defined in S142, and it is not necessary to define such a target speed in S148. By doing so, the first squeegee 22a and the second squeegee 22b do not stop but decelerate when located at the pause position Ps1 and the pause position Ps2, respectively.

[0049] In the above-described embodiment, the first squeegee 22a and the second squeegee 22b are made of urethane members. However, the first squeegee 22a and the second squeegee 22b may be made of plastic members or metal members.

[0050] The printing device of the present disclosure described above decelerates or stops the squeegee just before the viscous fluid, so that the speed at which the squeegee comes into contact with the viscous fluid can be reduced. This reduces the reaction force acting on the squeegee, making it possible to suppress deformation of the squeegee and lifting of the squeegee. Then, the squeegee is re-accelerated after that, so that printing can be performed at a high printing speed. This makes it possible to suppress deformation of the squeegee and lifting of the squeegee at the start of printing, and reduce the occurrence of printing defects.

[0051] The printing device of the present disclosure may further include a detection / estimation unit that detects or estimates the position of the viscous fluid on the screen mask, and the print start control unit may control the squeegee to decelerate or stop in front of the viscous fluid based on the detected or estimated position of the viscous fluid. In this way, the position at which the squeegee is decelerated or stopped can be set relatively accurately. In this case, the detection / estimation unit may have a measurement unit that measures the width of the viscous fluid in the printing direction, and may estimate the position of the viscous fluid when the next printing process is started based on the end position when the printing process was previously performed and the width of the viscous fluid measured by the measurement unit. In this way, the width of the viscous fluid can be measured every time a printing process is performed, and the position at which the squeegee is decelerated or stopped can be set relatively accurately every time a printing process is performed.

[0052] The printing device disclosed herein may further include a positioning unit that carries in and positions the printing target, and the print start control unit may lower the squeegee to the start position and start moving after the positioning unit has completed preparation of the printing target, and the detection and estimation unit may detect or estimate the position of the viscous fluid before preparation of the printing target is completed. In this way, the position of the viscous fluid is detected or estimated before preparation of the printing target is completed, so that the printing process can be performed smoothly at the timing when preparation of the printing target is completed. [Industrial Applicability]

[0053] The present disclosure is applicable to the screen printing machine manufacturing industry and the like. [Explanation of symbols]

[0054] 10 production system, 11 screen printing machine, 12 base, 13 component mounting machine, 20 print head, 21 head body, 22a first squeegee, 22b second squeegee, 23a first lift shaft, 23b second lift shaft, 24a first squeegee lift section, 24b second squeegee lift section, 25 height sensor, 26 linear encoder, 30 board transport device, 31 support base, 32 frame, 33 transport conveyor, 34 board support section, 35 board lift section, 36 support plate, 40 lift mechanism, 41 lift base, 43 guide rail, 44 motor, 45 ball screw shaft, 46 ball nut, 50 solder supply unit, 51 cartridge, 52 connection section, 60 head movement mechanism, 61 motor, 62 ball screw shaft, 63 ball nut, 65 driver, 70 Screen mask, 71 screen, 71m margin, 71o pattern hole, 72 support frame, 75 support rail, 80 control device, 81 CPU, 82 ROM, 83 RAM, 84 storage, 90 guide rail, 100 management device, 101 input device, 102 display device, S board.

Claims

1. A printing device that prints a viscous fluid on a printing target by moving a viscous fluid on a screen mask having an opening in a printing direction with a squeegee, A lifting unit that lifts and lowers the squeegee; A moving unit that moves the squeegee in a printing direction; a print control unit that executes a printing process to control the lifting unit and the moving unit so that the squeegee moves from a start position away from the viscous fluid on the screen mask on the upstream side in the printing direction to an end position on the downstream side in the printing direction across the opening; a print start control unit that starts the movement of the squeegee by accelerating from the start position, and controls the lifting unit and the moving unit so that the squeegee decelerates or stops just before the viscous fluid and then accelerates again, thereby starting the printing process; A printing device comprising:

2. 2. The printing device according to claim 1, a detection / estimation unit configured to detect or estimate a position of a viscous fluid on the screen mask, the print start control unit controls the squeegee to decelerate or stop in front of the viscous fluid based on the detected or estimated position of the viscous fluid. Printing device.

3. 3. The printing device according to claim 2, the detection and estimation unit has a measurement unit that measures a width of the viscous fluid in a printing direction, and estimates a position of the viscous fluid when the next printing process is to be started based on the end position when the printing process was previously executed and the width of the viscous fluid measured by the measurement unit. Printing device.

4. 4. The printing device according to claim 2, a positioning unit that carries in and positions the printing target, the print start control unit, after the positioning unit has completed preparation of the printing target, lowers the squeegee to the start position and starts movement; the detection / estimation unit detects or estimates a position of the viscous fluid by the time preparation of the printing target is completed; Printing device.

Images