Screen printing apparatus and screen printing method

Abstract

To provide a screen printer which allows a user to know a situation of plate separation.SOLUTION: A screen printer 1 includes: a table on which a printing object is placed; a screen plate which is disposed spaced apart from the printing object; a squeegee which slides on the screen plate while pressed against the screen plate; a measuring device 23; and a controller 24. The measuring device 23 measures a distance to the screen plate at a predetermined position located at the rear relative to the squeegee in a squeegee slide direction. The controller 24 acquires data of a height position of the screen plate based on outputs from the measuring device 23.SELECTED DRAWING: Figure 3

Description

TECHNICAL FIELD

[0001] The present invention relates to a screen printing apparatus and a screen printing method.

BACKGROUND ART

[0002] A known screen printing method includes: preparing a screen plate and a squeegee; arranging the screen plate at a distance from a printing target; placing a paste on the screen plate; and sliding the squeegee on the screen plate in a state of being pressed against the screen plate, thereby printing the paste on the printing target (see, for example, Patent Document 1).

PRIOR ART DOCUMENTS

PATENT DOCUMENTS

[0003]

PATENT DOCUMENT 1

SUMMARY OF THE INVENTION

PROBLEMS TO BE SOLVED BY THE INVENTION

[0004] In the screen printing method described above, after the squeegee passes, a phenomenon called plate separation occurs in which the screen plate separates from the printing target. If the state of this plate separation changes, the print quality of screen printing may deteriorate. For example, if the separation between the screen plate and the printing target becomes poor, that is, a delay occurs in the plate separation, the print quality in screen printing may deteriorate. Accordingly, a technique capable of ascertaining the state of plate separation is desired.

[0005] One aspect of the present invention aims to provide a screen printing apparatus capable of ascertaining the state of plate separation. Another aspect of the present invention aims to provide a screen printing method capable of ascertaining the state of plate separation.

MEANS FOR SOLVING THE PROBLEMS

[0006] A screen printing apparatus according to one embodiment comprises a table on which a workpiece to be printed is placed, a screen plate positioned at a distance from the workpiece, a squeegee that slides on the screen plate while being pressed against it, a measuring instrument, and a controller. The measuring instrument measures the distance from the squeegee to the screen plate at a predetermined position behind the squeegee in the sliding direction of the squeegee. The controller acquires data on the height position of the screen plate based on the output from the measuring instrument.

[0007] In the above embodiment, the screen plate height position data acquired by the controller corresponds to the screen plate height position data at a predetermined position behind the squeegee in the sliding direction of the squeegee. The screen release status can be reflected in the screen plate height position at the predetermined position mentioned above. Therefore, the above embodiment makes it possible to know the screen release status.

[0008] In one of the above embodiments, the controller may acquire data on the change in height over time. In a configuration where the controller acquires data on the temporal change in height position, the data on the temporal change in the screen plate's height position acquired by the controller corresponds to the data on the temporal change in the screen plate's height position at a predetermined position behind the squeegee in the sliding direction of the squeegee. The state of screen separation can be reliably reflected in the temporal change in the screen plate's height position at the aforementioned predetermined position. Therefore, this configuration can reliably determine the state of screen separation.

[0009] In one of the above embodiments, the controller may extract feature quantities of the screen plate's separation from data on the change in height over time. In a configuration where the controller extracts a feature of screen printing plate separation from data on changes in height over time, the state of plate separation is extracted as a quantitative value called a feature. Therefore, this configuration allows for quantitative knowledge of the state of plate separation.

[0010] In one of the above embodiments, the controller may determine the quality of the screen printing using the screen plate based on the feature quantities. In a configuration where the controller determines the quality of screen printing using a screen plate based on features, the quality of the screen printing is determined based on quantitative values. Therefore, this configuration appropriately determines the quality of screen printing.

[0011] In one of the above embodiments, the screen printing apparatus may include at least one of a first mechanism for adjusting the pressure of the squeegee on the screen plate, or a second mechanism for adjusting the distance between the material to be printed and the screen plate. The controller may control at least one of the first mechanism or the second mechanism to adjust at least one of the pressure or distance based on a feature quantity. In a configuration where the controller controls at least one of the first or second mechanism as described above, at least one of the pressing force or spacing is adjusted based on the characteristic quantity of the stencil release. Adjusting at least one of the pressing force or spacing can change the stencil release situation. Adjusting at least one of the pressing force or spacing based on the characteristic quantity of the stencil release can improve the stencil release situation. Therefore, one of the above embodiments can suppress a decrease in print quality.

[0012] In one of the above embodiments, the predetermined position may be located at a distance of 5 mm or more and 8 mm or less from the squeegee. The configuration in which the designated position is the position described above allows for a more reliable understanding of the print separation situation.

[0013] In one of the above embodiments, the measuring instrument may move together with the squeegee in the sliding direction of the squeegee. The configuration in which the measuring instrument moves together with the squeegee in the sliding direction of the squeegee allows for accurate measurement of the distance to the screen plate at the predetermined position described above, even while the squeegee is sliding.

[0014] In one of the above embodiments, the measuring instrument may include a laser displacement meter that irradiates the screen plate with laser light to measure the displacement of the screen plate. A measuring instrument that includes a laser displacement meter that irradiates the screen plate with laser light to measure the displacement of the screen plate can easily measure the distance to the screen plate at the predetermined position described above.

[0015] Another aspect of the screen printing method is a screen printing method for printing paste onto a substrate. This screen printing method includes preparing a screen plate, a squeegee, and a measuring instrument for measuring the distance to the screen plate. This screen printing method includes positioning the screen plate at a distance from the substrate, placing paste on the screen plate, and printing the paste onto the substrate by sliding the squeegee across the screen plate while pressing it against the screen plate. This screen printing method includes using the measuring instrument to measure the distance to the screen plate at a predetermined position behind the squeegee in the sliding direction of the squeegee, and obtaining data on the height position of the screen plate based on the measurement results.

[0016] In one of the other embodiments described above, the acquired data on the height position of the screen plate corresponds to the data on the height position of the screen plate at a predetermined position behind the squeegee in the sliding direction of the squeegee. Therefore, in one of the other embodiments described above, the state of screen release can be determined.

[0017] In one of the other embodiments described above, acquiring data may include acquiring data on the change in height over time. If data acquisition includes acquiring data on the change in height over time, the acquired data on the change in the height of the screen plate over time corresponds to the data on the change in the height of the screen plate over time at a predetermined position behind the squeegee in the sliding direction of the squeegee. Therefore, in this case, the stencil separation situation can be reliably determined.

[0018] In one of the other embodiments described above, the screen printing method may include extracting characteristic quantities of the screen plate's separation from data on the change in height over time. When the screen printing method includes extracting a feature quantity of plate separation of the screen plate from data of temporal change in height position, the state of plate separation is extracted as a quantitative value called the feature quantity. Therefore, in this case, the state of plate separation can be known quantitatively.

[0019] In the another aspect described above, the screen printing method may include determining the quality of screen printing using the screen plate based on the feature quantity. When the screen printing method includes determining the quality of screen printing using the screen plate based on the feature quantity, the quality of screen printing is determined based on a quantitative value. Therefore, in this case, the quality of screen printing is appropriately determined.

[0020] In the another aspect described above, the screen printing method may include adjusting at least one of the pressing force of the squeegee against the screen plate or the interval between the printing substrate and the screen plate based on the feature quantity. When the another aspect described above includes adjusting at least one of the pressing force of the squeegee against the screen plate or the interval between the printing substrate and the screen plate based on the feature quantity, at least one of the pressing force or the interval is adjusted based on the feature quantity of plate separation. Therefore, in this case, degradation of print quality can be suppressed.

[0021] In the another aspect described above, performing the measurement may include measuring the distance to the screen plate at a position separated by 5 mm or more and 8 mm or less from the squeegee. When performing the measurement includes measuring the distance to the screen plate at the position described above, the state of plate separation can be known even more reliably.

[0022] In the another aspect described above, performing the measurement may include moving a measuring instrument together with the squeegee in the sliding direction of the squeegee. When performing the measurement includes moving the measuring instrument together with the squeegee in the sliding direction of the squeegee, the distance to the screen plate at the aforementioned predetermined position can be appropriately measured even while the squeegee is sliding.

[0023] In the another aspect described above, performing the measurement may include using a laser displacement meter as the measuring instrument, irradiating the screen plate with laser light, and measuring the displacement of the screen plate. When performing the measurement includes using a laser displacement meter as the measuring instrument, irradiating the screen plate with laser light, and measuring the displacement of the screen plate, the distance to the screen plate at the aforementioned predetermined position can be easily measured. Effects of the Invention

[0024] One aspect of the present invention provides a screen printing apparatus capable of ascertaining the state of plate separation. Another aspect of the present invention provides a screen printing method capable of ascertaining the state of plate separation. Brief Description of the Drawings

[0025] [Figure 1] Figure 1 is a diagram showing the configuration of a screen printing apparatus according to one embodiment. [Figure 2] Figure 2 is a diagram showing the configuration of the screen printing apparatus according to the present embodiment. [Figure 3] Figure 3 is a block diagram showing the configuration of the screen printing apparatus according to the present embodiment. [Figure 4] Figure 4 is a diagram showing the temporal change in the distance between the measuring instrument and the screen plate. [Figure 5] Figure 5 is a diagram showing the temporal change in the distance between the measuring instrument and the screen plate. [Figure 6] Figure 6 is a diagram showing the configuration of the screen printing apparatus according to the present embodiment. [Figure 7] Figure 7 is a diagram showing the configuration of the screen printing apparatus according to the present embodiment. [Figure 8] Figure 8 is a diagram showing the temporal change in the height position of the screen plate. [Figure 9] Figure 9 is a diagram showing the change in the height of the screen over time. [Modes for carrying out the invention]

[0026] Embodiments of the present invention will be described in detail below with reference to the attached drawings. In this description, the same reference numerals will be used for the same element or element having the same function, and redundant explanations will be omitted.

[0027] The configuration of the screen printing apparatus 1 according to this embodiment will be described with reference to Figures 1 to 3. Figures 1 and 2 are diagrams showing the configuration of the screen printing apparatus according to this embodiment. Figure 3 is a block diagram showing the configuration of the screen printing apparatus according to this embodiment.

[0028] The screen printing apparatus 1 is a device for screen printing a paste P1 onto a substrate W1. The substrate W1 includes, for example, a ceramic green sheet or a substrate. The paste P1 includes a conductive paste, a resin paste, or a ceramic paste. As shown in Figure 1, the screen printing apparatus 1 includes a printing table mechanism A1, a plate mounting mechanism B1, and a printing mechanism C1 to perform the functions of screen printing.

[0029] The printing table mechanism A1 includes a table 2 and a drive unit 3. The table 2 includes a mounting surface 2a on which the object to be printed W1 is placed. That is, the screen printing apparatus 1 is equipped with a table 2 on which the object to be printed W1 is placed. The mounting surface 2a is, for example, rectangular in shape and supports the object to be printed W1 on the table 2. When screen printing is performed in the screen printing apparatus 1, the object to be printed W1 is placed on the mounting surface 2a by, for example, a conveying device. When screen printing is completed in the screen printing apparatus 1, the object to be printed W1 is discharged from the mounting surface 2a by a conveying device. The conveying device is, for example, a conveyor. The drive unit 3 adjusts the position of the mounting surface 2a of the table 2. In this embodiment, the direction along the mounting surface 2a of the table 2 is the first direction D1, the direction perpendicular to the mounting surface 2a of the table 2 is the second direction D2, and the direction perpendicular to the first direction D1 and the second direction D2 is the third direction D3.

[0030] The plate mounting mechanism B1 has a plate holding section 4. The plate holding section 4 includes a mold 5 and a screen plate 6. The mold 5 is a frame for mounting the screen plate 6 and is positioned at a distance from the mounting surface 2a. In this embodiment, the mold 5 is positioned at a distance from the mounting surface 2a in the second direction D2. The screen plate 6 is mounted inside the mold 5, stretched along the mounting surface 2a of the table 2. As described above, since the mold 5 is positioned at a distance from the mounting surface 2a, the screen plate 6 is also positioned at a distance from the mounting surface 2a. In this embodiment, the screen plate 6 is also positioned at a distance from the mounting surface 2a in the second direction D2. Since the object to be printed W1 is placed on the mounting surface 2a, when the screen printing device 1 performs screen printing, the screen plate 6 is positioned at a distance from the object to be printed W1. That is, the screen printing device 1 is equipped with a screen plate 6 that is positioned at a distance from the object to be printed W1. The distance between this screen plate 6 and the material to be printed W1 is adjusted, for example, to a predetermined distance before printing begins.

[0031] The panel mounting mechanism B1 further comprises a support base 7, a base 8, legs 9, and a spacing adjustment mechanism 10. The support base 7 supports the formwork 5 and the screen panel 6. The base 8 is provided on both sides of the table 2 in a third direction D3 and extends beyond the table 2 in a length greater than that in a first direction D1. The legs 9 are provided on the base 8 and connect the base 8 to the support base 7. In this embodiment, multiple legs 9 are provided on the base 8.

[0032] The spacing adjustment mechanism 10 is mounted on the support base 7. The spacing adjustment mechanism 10 is a mechanism for moving the plate holder 4 in the second direction D2. The spacing adjustment mechanism 10 adjusts the spacing between the material to be printed W1 and the screen plate 6 by moving the plate holder 4 in the second direction D2. Therefore, the spacing adjustment mechanism 10 can also be said to be a mechanism for adjusting the spacing between the material to be printed W1 and the screen plate 6. In this embodiment, the spacing adjustment mechanism 10 adjusts the spacing between the material to be printed W1 and the screen plate 6 by motor drive. To realize this function, the spacing adjustment mechanism 10 includes a motor 10a and a shaft 10b. The motor 10a is located on the support base 7. The shaft 10b is connected to the motor 10a and extends from the motor 10a in the second direction D2. The shaft 10b supports the plate holder 4. For example, the motor 10a is a servo motor and the shaft 10b is a ball screw. In this embodiment, the motor 10a rotates the shaft 10b, causing the plate holder 4 to move in the second direction D2, thereby adjusting the distance between the material to be printed W1 and the screen plate 6.

[0033] The printing mechanism C1 includes a machine frame 11, guide rails 12, a support base 13, a pressing force adjustment mechanism 14, a fixing mechanism 15, a squeegee 16, and a blade 17. The machine frame 11 is positioned on the plate mounting mechanism B1 and houses the guide rails 12, the support base 13, the pressing force adjustment mechanism 14, and the fixing mechanism 15. The guide rails 12 extend within the machine frame 11 along a first direction D1. The support base 13 is supported by the guide rails 12. In this embodiment, the support base 13 is supported by the guide rails 12 so as to be movable in the first direction D1.

[0034] The pressing force adjustment mechanism 14 is a mechanism for moving the squeegee 16 in a second direction D2 and adjusting the pressing force of the squeegee 16 against the screen plate 6. In this embodiment, the pressing force adjustment mechanism 14 moves the squeegee 16 in a second direction D2 and adjusts the pressing force of the squeegee 16 against the screen plate 6 by motor drive. To achieve this function, the pressing force adjustment mechanism 14 includes a motor 14a and a shaft 14b. The motor 14a is located on a support base 13. The shaft 14b is connected to the motor 14a and extends from the motor 14a in a second direction D2. For example, the motor 14a is a servo motor and the shaft 14b is a ball screw. For example, if the pressing force adjustment mechanism 14 constitutes the first mechanism, then the spacing adjustment mechanism 10 constitutes the second mechanism.

[0035] The fixing mechanism 15 is a mechanism for fixing the blade 17. To achieve this function, the fixing mechanism 15 includes a base 15a and a connecting portion 15b. The base 15a is mounted on the support base 13. In this embodiment, the base 15a is mounted on the support base 13 so as to be adjacent to the motor 14a in the first direction D1. That is, in this embodiment, the pressing force adjustment mechanism 14 and the fixing mechanism 15 are arranged to be adjacent to each other in the first direction D1. The connecting portion 15b extends from one end of the base 15a in the second direction D2.

[0036] The squeegee 16 is a component used to print paste P1 placed on the screen plate 6 onto the substrate W1 by sliding along the screen plate 6 while being pressed against it. The squeegee 16 slides along the screen plate 6 in a first direction D1. The squeegee 16 is attached to the shaft 14b so as to be positioned on the screen plate 6. When the screen printing apparatus 1 performs screen printing, the squeegee 16 is pressed against the screen plate 6 by the pressing force adjustment mechanism 14. In this embodiment, the motor 14a rotates the shaft 14b, causing the squeegee 16 to move in a second direction D2 and be pressed against the screen plate 6.

[0037] The blade 17 is a component for spreading the paste P1 placed on the screen plate 6 before the start of screen printing with the squeegee 16. The blade 17 spreads the paste P1 on the screen plate 6 by moving across it. In this embodiment, the blade 17 spreads the paste P1 on the screen plate 6 by moving across it while separated from the screen plate 6. The blade 17 moves across the screen plate 6 in the first direction D1. In this embodiment, the blade 17 moves in the first direction D1 and does not move in the second direction D2. That is, in this embodiment, the distance between the blade 17 and the screen plate 6 is not adjusted. The blade 17 is attached to the connecting portion 15b so that it is positioned on the screen plate 6.

[0038] The direction of movement of the blade 17 is not limited to the first direction D1. For example, the blade 17 may move in a second direction D2 to adjust the distance from the screen plate 6. In this case, the printing mechanism C1 may have another spacing adjustment mechanism for adjusting the distance between the blade 17 and the screen plate 6. The above-mentioned spacing adjustment mechanism may move the blade 17 in the second direction D2 by motor drive to adjust the distance between the blade 17 and the screen plate 6.

[0039] As described above, the squeegee 16 slides on the screen plate 6 in the first direction D1, and the blade 17 moves on the screen plate 6 in the first direction D1. The printing mechanism C1 further includes pulleys 18, 19, a belt 20, a motor 21, and a belt 22 to achieve this function. The pulleys 18, 19, belt 20, motor 21, and belt 22 are housed within the machine frame 11. The pulleys 18, 19 are positioned at both ends of the support base 13 in the first direction D1. Belt 20 is stretched between pulleys 18 and 19 and is also connected to the support base 13. The motor 21 is connected to pulley 18 via belt 22. As a result, the rotational drive of the motor 21 is transmitted to pulley 18 via belt 22, causing belt 20 to rotate. As belt 20 rotates, the support base 13 moves in the first direction D1, from pulley 18 toward pulley 19. As a result, the squeegee 16 slides on the screen plate 6 in the direction from pulley 18 to pulley 19 within the first direction D1. Similarly, the blade 17 moves on the screen plate 6 in the direction from pulley 18 to pulley 19 within the first direction D1. In other words, in this embodiment, the sliding direction of the squeegee 16 and the movement direction of the blade 17 are in the direction from pulley 18 to pulley 19 within the first direction D1.

[0040] The screen printing apparatus 1 further comprises a measuring instrument 23 and a controller 24. In this embodiment, the screen printing apparatus 1 has one measuring instrument 23. The measuring instrument 23 is attached to the shaft 14b. In this embodiment, the measuring instrument 23 includes a connecting part 23a and a laser displacement meter 23b. The connecting part 23a is a member for connecting the laser displacement meter 23b and the shaft 14b. One end of the connecting part 23a is connected to the shaft 14b. The other end of the connecting part 23a is connected to the laser displacement meter 23b.

[0041] The laser displacement meter 23b measures the displacement of the screen plate 6 by irradiating it with laser light. In this embodiment, as shown in Figure 2, the laser displacement meter 23b measures the displacement of the screen plate 6 by irradiating it with laser light at a predetermined position S1 behind the squeegee 16 in the sliding direction of the squeegee 16. As a result, the measuring instrument 23 measures the distance to the screen plate 6 at the predetermined position S1 behind the squeegee 16 in the sliding direction of the squeegee 16. The measuring instrument 23 measures the distance to the screen plate 6, for example, at predetermined time intervals. The measuring instrument 23 sequentially outputs the measured distance data to the controller 24. The predetermined position S1 is set to a value within a range that allows us to know the state of stencil release. The predetermined position S1 is set to a value within a range that allows us to know, for example, that there is a delay in stencil release. The predetermined position S1 may be set, for example, according to the shape or width of the squeegee 16. In this embodiment, the predetermined position S1 is a position 5 mm or more and 8 mm or less away from the squeegee 16. That is, in this embodiment, the predetermined position S1 is a position 5 mm or more and 8 mm or less behind the squeegee 16 in the sliding direction of the squeegee 16.

[0042] As described above, the measuring instrument 23 is attached to the shaft 14b. Therefore, the measuring instrument 23 moves together with the squeegee 16 in the sliding direction of the squeegee 16. In this embodiment, during screen printing, the measuring instrument 23 moves together with the squeegee 16 in the sliding direction of the squeegee 16 and measures the distance to the screen plate 6 at a predetermined position S1 at predetermined time intervals. The measuring instrument 23 does not need to be attached to the shaft 14b. The measuring instrument 23 may be attached to a separate moving mechanism from the shaft 14b. In this case, the moving mechanism moves the measuring instrument 23 so that it moves together with the squeegee 16 in the sliding direction of the squeegee 16.

[0043] The controller 24 is connected to the measuring instrument 23, the spacing adjustment mechanism 10, and the pressing force adjustment mechanism 14. The controller 24 controls the operation of the measuring instrument 23 and the operation of at least one of the spacing adjustment mechanism 10 and the pressing force adjustment mechanism 14. Based on the data output from the measuring instrument 23, the controller 24 controls the operation of at least one of the spacing adjustment mechanism 10 and the pressing force adjustment mechanism 14. The controller 24 includes, for example, a CPU (Central Processing Unit), ROM (Read Only Memory), and RAM (Random Access Memory). The controller 24 includes the functional elements shown in Figure 3, for example, by loading a program stored in ROM into RAM and executing the program loaded into RAM with the CPU. The controller 24 includes an acquisition unit 25, an extraction unit 26, a determination unit 27, and a control unit 28. The controller 24 includes a storage unit (not shown) that stores data output from the measuring instrument 23 and calculation results. The storage unit stores parameters and numerical values ​​necessary for processing by the controller 24.

[0044] The acquisition unit 25 acquires data on the height position of the screen plate 6 based on the data output from the measuring instrument 23. In this embodiment, the acquisition unit 25 acquires data on the distance to the screen plate 6 at a predetermined position S1 from the storage unit. The acquisition unit 25 calculates the height position of the screen plate 6 based on the distance to the screen plate 6 at the predetermined position S1 and the height position of the measuring instrument 23. In this embodiment, the height position indicates the distance to the object to be printed W1 in the second direction D2. That is, the height position of the measuring instrument 23 indicates the distance between the measuring instrument 23 and the object to be printed W1 in the second direction D2, and the height position of the screen plate 6 indicates the distance between the screen plate 6 and the object to be printed W1 in the second direction D2. In this embodiment, the acquisition unit 25 calculates the difference between the distance to the screen plate 6 at the predetermined position S1 and the height position of the measuring instrument 23 as the height position of the screen plate 6. Thus, the acquisition unit 25 acquires data on the height position of the screen plate 6. The acquisition unit 25 performs the above-described process on each data point of the distance to the screen panel 6 at a predetermined position S1, which is stored in the storage unit, thereby acquiring data on the change in the height position of the screen panel 6 over time. The acquisition unit 25 sends the acquired data on the change in the height position of the screen panel 6 over time to the extraction unit 26. The controller 24 may store the data on the height position of the screen panel 6 acquired based on the data output from the measuring instrument 23, without storing the data output from the measuring instrument 23. That is, the controller 24 may sequentially acquire and store the data on the height position of the screen panel 6 based on the data output from the measuring instrument 23.

[0045] The extraction unit 26 extracts characteristic quantities of the print separation of the screen plate 6 from the data on the change in the height position of the screen plate 6 over time, which is sent from the acquisition unit 25. In this embodiment, the characteristic quantities of the print separation of the screen plate 6 represent the characteristics of the print separation situation of the screen plate 6. For example, the characteristic quantities of the print separation of the screen plate 6 represent the variation in the height position of the screen plate 6. In this embodiment, the extraction unit 26 extracts the characteristic quantities of the print separation of the screen plate 6 based on the variation in the height position of the screen plate 6.

[0046] The extraction unit 26 extracts the feature quantities of the print separation from the screen plate 6, for example, as follows: The extraction unit 26 calculates the average value of the height position of the screen panel 6 from the data on the change in the height position of the screen panel 6 over time sent from the acquisition unit 25. The extraction unit 26 may calculate the average value of the height position of the screen panel 6 using all data points from the data on the change in the height position of the screen panel 6 over time. Alternatively, the extraction unit 26 may calculate the average value of the height position of the screen panel 6 using only some of the data points from the data on the change in the height position of the screen panel 6 over time.

[0047] The extraction unit 26 calculates the standard deviation of the height position of the screen panel 6 from the data on the change in the height position of the screen panel 6 over time, obtained from the acquisition unit 25. The extraction unit 26 calculates the standard deviation of the height position of the screen panel 6 using the average value of the calculated height position of the screen panel 6. The extraction unit 26 calculates the standard deviation of the height position of the screen panel 6 as follows. The extraction unit 26 sums the squares of the differences between the height position of the screen panel 6 at the data points used to calculate the average value and the calculated average height position of the screen panel 6. The extraction unit 26 divides the sum by the number of data points used. The extraction unit 26 calculates the standard deviation of the height positions of the screen panel 6 by taking the square root of the divided value.

[0048] The extraction unit 26 extracts the ratio of the average height position of the screen plate 6 to the standard deviation of the height position of the screen plate 6 as a feature of the screen plate 6's print separation. Alternatively, the extraction unit 26 may extract the standard deviation of the height position of the screen plate 6 as a feature of the screen plate 6's print separation. The extraction unit 26 sends the extracted feature of the screen plate 6's print separation to the determination unit 27 and the control unit 28. The extraction unit 26 may store the extracted feature of the screen plate 6's print separation in the storage unit.

[0049] The determination unit 27 determines the quality of the screen printing using the screen plate 6. The determination unit 27 determines the quality of the screen printing using the screen plate 6 based on the characteristic quantity of the screen plate 6's ink separation. In this embodiment, the determination unit 27 compares the characteristic quantity of the screen plate 6's ink separation with a predetermined threshold value and then determines the quality of the screen printing using the screen plate 6. If the feature amount of the screen plate 6's stencil separation is greater than a predetermined threshold, the determination unit 27 determines that the variation in the height position of the screen plate 6 is small and that the screen printing performed is good. If the feature amount of the screen plate 6's stencil separation is smaller than a predetermined threshold, the determination unit 27 determines that the variation in the height position of the screen plate 6 is large and that the screen printing performed is not good. The determination unit 27 sends information indicating the quality of the screen printing using the screen plate 6 to the control unit 28. The determination unit 27 may store the information indicating the quality of the screen printing using the screen plate 6 in the storage unit.

[0050] The control unit 28 controls the operation of at least one of the pressing force adjustment mechanism 14 or the spacing adjustment mechanism 10. Based on the characteristic quantities of the screen plate 6's stencil release sent from the extraction unit 26, the control unit 28 controls the operation of at least one of the pressing force of the squeegee 16 against the screen plate 6 or the spacing between the screen plate 6 and the material to be printed W1. In this embodiment, in addition to the characteristic quantities of the screen plate 6's stencil release, the control unit 28 controls the operation of at least one of the pressing force adjustment mechanism 14 or the spacing adjustment mechanism 10 based on information indicating the quality of screen printing using the screen plate 6 sent from the determination unit 27.

[0051] The control unit 28 controls the operation of at least one of the pressing force adjustment mechanism 14 or the spacing adjustment mechanism 10 as follows: If the information indicating the quality of the screen printing indicates that the screen printing is not good, the control unit 28 controls the operation of at least one of the pressing force adjustment mechanism 14 or the spacing adjustment mechanism 10 based on the characteristic quantity of the screen plate 6's separation. In this case, the control unit 28 controls the operation of at least one of the pressing force adjustment mechanism 14 or the spacing adjustment mechanism 10 in order to perform good screen printing. For example, the control unit 28 outputs a signal to the spacing adjustment mechanism 10 to increase the spacing between the screen plate 6 and the material to be printed W1 so that the screen printing is performed well. The spacing adjustment mechanism 10 increases the spacing between the screen plate 6 and the material to be printed W1 based on the signal from the control unit 28.

[0052] The control unit 28 may output a signal to the pressure adjustment mechanism 14 to increase or decrease the pressure of the squeegee 16 against the screen plate 6 so that screen printing is performed well. In this case, the pressure adjustment mechanism 14 increases or decreases the pressure of the squeegee 16 against the screen plate 6 based on the signal from the control unit 28. When the distance between the screen plate 6 and the material to be printed W1 increases, the tension of the screen plate 6 can change the pressing force of the squeegee 16 against the screen plate 6. Therefore, when the control unit 28 controls the operation of both the pressing force adjustment mechanism 14 and the distance adjustment mechanism 10 in order to perform screen printing well, the control unit 28 may output a signal to the pressing force adjustment mechanism 14 to increase or decrease the pressing force of the squeegee 16 against the screen plate 6 in accordance with the amount of increase in the distance. In other words, the control unit 28 may output signals to the distance adjustment mechanism 10 and the pressing force adjustment mechanism 14, respectively, to increase the distance between the screen plate 6 and the material to be printed W1 and to increase or decrease the pressing force of the squeegee 16 against the screen plate 6 in order to perform screen printing well.

[0053] If the information indicating the quality of the screen printing indicates that the screen printing was performed well, the control unit 28 does not need to control the operation of the pressing force adjustment mechanism 14 and the spacing adjustment mechanism 10. In other words, if the screen printing is performed well, the pressing force of the squeegee 16 against the screen plate 6 and the spacing between the screen plate 6 and the material to be printed W1 do not need to be adjusted.

[0054] As explained above, in the screen printing apparatus 1, the data on the height position of the screen plate 6 acquired by the controller 24 corresponds to the data on the height position of the screen plate 6 at a predetermined position S1 behind the squeegee 16 in the sliding direction of the squeegee 16. The state of screen separation can be reflected in the height position of the screen plate 6 at the predetermined position S1. Therefore, the screen printing apparatus 1 can know the state of screen separation.

[0055] In the screen printing apparatus 1, the controller 24 acquires data on the change in the height position of the screen plate 6 over time. In the screen printing apparatus 1, the data on the change in the height position of the screen plate 6 over time, acquired by the controller 24, corresponds to the data on the change in the height position of the screen plate 6 over time at a predetermined position S1 behind the squeegee 16 in the sliding direction of the squeegee 16. The state of screen separation can be reliably reflected in the change in the height position of the screen plate 6 over time at the predetermined position S1. Therefore, the screen printing apparatus 1 can reliably know the state of screen separation.

[0056] In the screen printing apparatus 1, the controller 24 extracts characteristic quantities of the screen plate 6's separation from the screen plate 6 based on data of the change in the height position of the screen plate 6 over time. In screen printing apparatus 1, the state of ink release is extracted as a quantitative value called a feature. Therefore, screen printing apparatus 1 can quantitatively determine the state of ink release.

[0057] In the screen printing apparatus 1, the controller 24 determines the quality of the screen printing using the screen plate 6 based on the characteristic quantities of the screen plate 6's separation from the plate. In the screen printing device 1, the quality of the screen printing is determined based on quantitative values. Therefore, the screen printing device 1 appropriately determines the quality of the screen printing.

[0058] In the screen printing apparatus 1, the controller 24 controls at least one of the pressing force adjustment mechanism 14 or the spacing adjustment mechanism 10 to adjust at least one of the pressing force of the squeegee 16 against the screen plate 6 or the spacing between the material to be printed W1 and the screen plate 6, based on the characteristic quantity of the screen plate 6's separation from the plate. In the screen printing apparatus 1, at least one of the pressing force or the spacing is adjusted based on the characteristic quantity of the screen plate 6's release. Adjusting at least one of the pressing force or the spacing can change the release condition. Adjusting at least one of the pressing force or spacing based on the characteristic quantity of the release condition can improve the release condition. Therefore, the screen printing apparatus 1 can suppress a decrease in print quality.

[0059] In the screen printing apparatus 1, the predetermined position S1 is a position that is 5 mm to 8 mm away from the squeegee 16. The screen printing apparatus 1 can more reliably determine the state of screen separation.

[0060] In the screen printing apparatus 1, the measuring instrument 23 moves together with the squeegee 16 in the sliding direction of the squeegee 16. The screen printing apparatus 1 appropriately measures the distance to the screen plate 6 at a predetermined position S1, even while the squeegee 16 is sliding.

[0061] In the screen printing apparatus 1, the measuring instrument 23 includes a laser displacement meter 23b that irradiates the screen plate 6 with laser light to measure the displacement of the screen plate 6. The screen printing apparatus 1 easily measures the distance to the screen plate 6 at a predetermined position S1.

[0062] Next, a screen printing method using the screen printing apparatus 1 according to this embodiment will be described with reference to Figures 4 to 9. Figures 4 and 5 are diagrams showing the change in the distance between the measuring instrument and the screen plate over time. Figures 6 and 7 are diagrams showing the configuration of the screen printing apparatus according to this embodiment. Figures 8 and 9 are diagrams showing the change in the height position of the screen plate over time.

[0063] In this embodiment, the operation of screen printing and the operation of the measuring instrument 23 and controller 24 are performed. The operation of screen printing will be described below. In this printing method, first, a screen printing apparatus 1 equipped with a screen plate 6, a squeegee 16, and a measuring instrument 23 is prepared. That is, in this printing method, a screen plate 6, a squeegee 16, and a measuring instrument 23 for measuring the distance to the screen plate 6 are prepared. Next, the object to be printed W1 is placed on the mounting surface 2a of the table 2. In this printing method, the screen printing apparatus 1 may be prepared with the object to be printed W1 already placed on the mounting surface 2a. Next, the screen plate 6 is positioned at a distance from the object to be printed W1. In this printing method, the distance between the screen plate 6 and the object to be printed W1 is adjusted by the spacing adjustment mechanism 10. Next, paste P1 is placed on the screen plate 6.

[0064] Next, paste P1 is spread onto the screen plate 6. In this printing method, paste P1 is spread onto the screen plate 6 by moving the blade 17 across the screen plate 6 while keeping it separated from the screen plate 6. The blade 17 moves across the screen plate 6 in the direction from pulley 18 to pulley 19 within the first direction D1. At this time, the squeegee 16 and measuring instrument 23 move along with the blade 17 in the direction of the blade 17's movement, while keeping a distance from the screen plate 6.

[0065] Next, the pressing force adjustment mechanism 14 moves the squeegee 16 and measuring instrument 23 in the second direction D2. As a result, the squeegee 16 and measuring instrument 23 approach the screen plate 6, and the squeegee 16 is pressed against the screen plate 6. Next, the squeegee 16 is pressed against the screen plate 6 and slid across the screen plate 6 to print the paste P1 onto the substrate W1. In other words, the squeegee 16 is pressed against the screen plate 6 and slid across the screen plate 6 to print the paste P1 onto the substrate W1. The squeegee 16 slides across the screen plate 6 in the direction from pulley 18 to pulley 19 within the first direction D1. In this printing method, the motor 21 rotates to press the squeegee 16 against the screen plate 6 and slide it across the screen plate 6. At this time, the blade 17 and measuring instrument 23 move along with the squeegee 16 in the sliding direction of the squeegee 16, at a distance from the screen plate 6.

[0066] Next, the pressure adjustment mechanism 14 moves the squeegee 16 again in the second direction D2. This releases the pressure on the screen plate 6 from the squeegee 16, and the squeegee 16 returns to its position at the start of printing in the second direction D2. In other words, the squeegee 16 moves away from the screen plate 6 in the second direction D2. Next, the motor 21 rotates, moving the squeegee 16 in the first direction D1. This returns the squeegee 16 to its position at the start of printing in the first direction D1. During this process, the squeegee 16, blade 17, and measuring instrument 23 move across the screen plate 6 at a distance from it.

[0067] Next, the operation of the measuring instrument 23 and the controller 24 will be described. In this printing method, first, the measuring instrument 23 measures the distance to the screen plate 6 at a predetermined position S1. That is, in this printing method, the measuring instrument 23 is used to measure the distance to the screen plate 6 at a predetermined position S1 behind the squeegee 16 in the sliding direction of the squeegee 16. For example, during the screen printing operation described above, the measuring instrument 23 measures the distance to the screen plate 6 at a predetermined position S1. In this printing method, when measuring the distance to the screen plate 6 at a predetermined position S1, the predetermined position S1 is set to a position that is 5 mm or more and 8 mm or less away from the squeegee 16. As described above, the measuring instrument 23 includes a laser displacement meter 23b. Therefore, in this printing method, when measuring the distance to the screen plate 6 at a predetermined position S1, the laser displacement meter 23b is used as the measuring instrument 23, and the displacement of the screen plate 6 is measured by irradiating the screen plate 6 with laser light. The measuring instrument 23 outputs the measurement result to the controller 24. The controller 24 stores data regarding the distance to the screen version 6 in its memory unit.

[0068] Next, the acquisition unit 25 acquires data on the height position of the screen plate 6 based on the measurement results. In other words, in this printing method, data on the height position of the screen plate 6 is acquired based on the measurement results of the measuring instrument 23. In acquiring the data on the height position of the screen plate 6, the acquisition unit 25 first acquires data on the distance to the screen plate 6 at a predetermined position S1 from the storage unit. The distance to the screen plate 6 at the predetermined position S1 changes during the screen printing operation described above, as shown in Figure 4. In the graph shown in Figure 4, the horizontal axis represents time, and the vertical axis represents the distance to the screen plate 6 at the predetermined position S1.

[0069] In the example shown in Figure 4, the period up to time t1 corresponds to the period during which the blade 17 spreads the paste P1 onto the material to be printed W1. During the period up to time t1, as described above, the squeegee 16 and measuring instrument 23 move on the screen plate 6 at a distance from the screen plate 6. Therefore, during the period up to time t1, the distance to the screen plate 6 at the predetermined position S1 remains constant.

[0070] The period from time t1 to time t2 corresponds to the period until the squeegee 16 is pressed against the screen plate 6. That is, at time t1, the movement of the squeegee 16 and the measuring instrument 23 in the second direction D2 begins, and at time t2, the squeegee 16 is pressed against the screen plate 6. Therefore, during the period from time t1 to time t2, the distance to the screen plate 6 at the predetermined position S1 decreases.

[0071] The period from time t2 to time t3 corresponds to the period during which the squeegee 16 slides on the screen plate 6 while being pressed against it. In other words, the period from time t2 to time t3 corresponds to the period during which paste P1 is printed on the material W1 to be printed. That is, screen printing starts at time t2 and ends at time t3. During the period from time t2 to time t3, since screen printing is performed with the squeegee 16 pressed against the screen plate 6, the distance to the screen plate 6 at a predetermined position S1 does not change significantly compared to the period from time t1 to time t2.

[0072] However, as shown in Figure 5, the distance to the screen plate 6 at the predetermined position S1 changes subtly during the period from time t2 to time t3. In the graph shown in Figure 5, the horizontal axis represents time, and the vertical axis represents the distance to the screen plate 6 at the predetermined position S1. The graph shown in Figure 5 is an enlarged version of the graph from time t2 to time t3 in Figure 4. In the example shown in Figure 5, the distance to the screen plate 6 at the predetermined position S1 gradually decreases from time t2 to time t3, with small changes superimposed on each other.

[0073] Returning to Figure 4, the period from time t3 to time t4 corresponds to the period during which the squeegee 16 moves in the second direction D2 away from the screen plate 6. That is, at time t3, the pressure on the screen plate 6 by the squeegee 16 is released, and at time t4, the squeegee 16 returns to its position at the start of printing in the second direction D2. Therefore, during the period from time t3 to time t4, the distance to the screen plate 6 at the predetermined position S1 increases.

[0074] The period from time t4 corresponds to the period during which the squeegee 16 moves on the screen plate 6 in the first direction D1. As described above, the squeegee 16 and measuring instrument 23 move on the screen plate 6 at a distance from the screen plate 6. Therefore, during the period from time t4, the distance to the screen plate 6 at the predetermined position S1 remains constant.

[0075] The acquisition unit 25 obtains data on the height position of the screen plate 6 by calculating the height position of the screen plate 6 from the distance to the screen plate 6 at a predetermined position S1, which shows the changes described above. In this printing method, the acquisition unit 25 calculates the difference between the distance to the screen plate 6 at the predetermined position S1 and the height position of the measuring instrument 23 as the height position of the screen plate 6. In this way, the acquisition unit 25 obtains data on the height position of the screen plate 6. In this printing method, the acquisition unit 25 obtains data on the change in the height position of the screen plate 6 over time by performing the above-described process on each of the acquired data on the distance to the screen plate 6 at the predetermined position S1. The acquisition unit 25 sends the acquired data on the change in the height position of the screen plate 6 over time to the extraction unit 26. The controller 24 may store the acquired data on the height position of the screen plate 6 instead of storing the data output from the measuring instrument 23 as described above.

[0076] Next, the extraction unit 26 extracts the characteristic quantities of the screen plate 6's ink separation from the data on the change in the height position of the screen plate 6 over time. In this printing method, the extraction unit 26 extracts the characteristic quantities of the screen plate 6's ink separation based on the variation in the height position of the screen plate 6. In this printing method, for example, the characteristic quantities of the screen plate 6's ink separation are extracted as follows.

[0077] First, the extraction unit 26 calculates the average height of the screen plate 6 from data on the change in the height of the screen plate 6 over time. In this printing method, the average height of the screen plate 6 is calculated using data points from the period between time point t2 and time point t3 of the data on the change in the height of the screen plate 6 over time. In other words, in this printing method, the average height of the screen plate 6 is calculated when paste P1 is printed on the substrate W1.

[0078] Next, the extraction unit 26 calculates the standard deviation of the height position of the screen panel 6 from the data on the change in the height position of the screen panel 6 over time. First, the extraction unit 26 sums the squares of the difference between the height position of the screen panel 6 during the period from time t2 to time t3 and the calculated average value of the height position of the screen panel 6. Next, the extraction unit 26 divides the sum by the number of data points during the period from time t2 to time t3. Next, the extraction unit 26 calculates the standard deviation by taking the square root of the divided value. This calculates the standard deviation of the height position of the screen panel 6 during the period from time t2 to time t3. Next, the extraction unit 26 extracts the ratio of the average value of the height positions of the screen plate 6 to the standard deviation of the height positions of the screen plate 6 as a feature quantity of the screen plate 6's separation from the screen. The extraction unit 26 sends the extracted feature quantity of the screen plate 6's separation from the screen to the determination unit 27 and the control unit 28.

[0079] Next, the determination unit 27 determines whether the screen printing of the screen plate 6 is good or bad. In this printing method, the determination unit 27 determines whether the screen printing of the screen plate 6 is good or bad based on the characteristic quantity of the screen release of the screen plate 6. In this printing method, the determination unit 27 compares the characteristic quantity of the screen release of the screen plate 6 with a predetermined threshold and then determines whether the screen printing using the screen plate 6 is good or bad. If the characteristic quantity of the screen release of the screen plate 6 is greater than the predetermined threshold, the determination unit 27 determines that the screen printing performed is good. If the characteristic quantity of the screen release of the screen plate 6 is less than the predetermined threshold, the determination unit 27 determines that the screen printing performed is not good. The determination unit 27 sends information indicating whether the screen printing of the screen plate 6 is good or bad to the control unit 28.

[0080] Next, the control unit 28 controls at least one of the pressing force adjustment mechanism 14 or the spacing adjustment mechanism 10. In this printing method, the control unit 28 controls at least one of the pressing force adjustment mechanism 14 or the spacing adjustment mechanism 10 to adjust at least one of the pressing force of the squeegee 16 against the screen plate 6 or the spacing between the screen plate 6 and the material to be printed W1, based on the characteristic quantity of the screen plate 6's stencil separation sent from the extraction unit 26. In this printing method, the control unit 28 controls at least one of the pressing force adjustment mechanism 14 or the spacing adjustment mechanism 10 based on the characteristic quantity of the screen plate 6's stencil separation, as well as information indicating the quality of the screen printing of the screen plate 6 sent from the determination unit 27.

[0081] In this printing method, the control unit 28 controls at least one of the pressing force adjustment mechanism 14 or the spacing adjustment mechanism 10 as follows. If the information indicating the quality of the screen printing indicates that the screen printing was not performed well, the control unit 28 controls at least one of the pressing force adjustment mechanism 14 or the spacing adjustment mechanism 10 based on the characteristic quantity of the screen plate 6's stencil separation. In this case, in order to perform screen printing well, the control unit 28 controls the operation of at least one of the pressing force adjustment mechanism 14 or the spacing adjustment mechanism 10. For example, the spacing between the screen plate 6 and the material to be printed W1 is increased so that screen printing is performed well. Instead of increasing the spacing between the screen plate 6 and the material to be printed W1, the pressing force of the squeegee 16 against the screen plate 6 may be increased or decreased. In order to perform screen printing well, the spacing between the screen plate 6 and the material to be printed W1 may be increased and the pressing force of the squeegee 16 against the screen plate 6 may be increased or decreased.

[0082] If the information indicating the quality of the screen printing on the screen plate 6 indicates that the screen printing was performed well, the control unit 28 does not need to control the operation of at least one of the pressing force adjustment mechanism 14 or the spacing adjustment mechanism 10. In other words, if the screen printing is performed well, the pressing force of the squeegee 16 on the screen plate 6 and the spacing between the screen plate 6 and the material to be printed W1 do not need to be adjusted.

[0083] Here, we will explain the relationship between the change in the height position of the screen plate 6 over time and the state of ink release from the screen plate 6. The inventors conducted experiments to clarify the relationship between the change in the height position of the screen plate 6's ink release over time and the state of ink release from the screen plate 6. First, before describing the details of the experiments, we will explain the relationship between the squeegee 16, the screen plate 6, and the substrate W1 in the state of good ink release and the state of delayed ink release.

[0084] The example shown in Figure 6 illustrates the relationship between the squeegee 16, the screen plate 6, and the substrate W1 when the ink release is good. Good ink release means, for example, that the screen plate 6 quickly separates from the substrate W1 after passing through the squeegee 16. The example shown in Figure 7 illustrates the relationship between the squeegee 16, the screen plate 6, and the substrate W1 when the ink release is poor, i.e., when there is a delay in ink release. A delay in ink release means, for example, that even after passing through the squeegee 16, the screen plate 6 and the substrate W1 remain in contact, as shown in Figure 7. For example, when the ink release is good, the screen plate 6 and the substrate W1 are separated at a predetermined position S1, while when there is a delay in ink release, the screen plate 6 and the substrate W1 are in contact at the predetermined position S1. Therefore, the predetermined position S1 can be said to be a position where a delay in ink release can be detected.

[0085] Next, the inventors will explain the details of the experiment they conducted. First, the inventors measured the distance from a predetermined position S1 to the screen plate 6 during the period from time t2 to time t3, under conditions where the stencil release was good and under conditions where there was a delay in stencil release, and obtained data on the change in the height position of the screen plate 6 over time. In other words, the inventors first obtained data on the change in the height position of the screen plate 6 over time during screen printing by actual measurement. Figure 8 is a graph showing the change in the height position of the screen plate 6 over time, based on actual measurement. In the graph shown in Figure 8, the horizontal axis represents time, and the vertical axis represents the height position of the screen plate 6. In Figure 8, change G1 shows the change in the height position of the screen plate 6 over time under conditions where the stencil release is good. Change G2 shows the change in the height position of the screen plate 6 over time under conditions where there is a delay in stencil release.

[0086] As described above, when the stencil release is good, the screen plate 6 and the material to be printed W1 are separated at a predetermined position S1, so from time t2 to time t3, the height of the screen plate 6 decreases gradually, with small changes superimposed. On the other hand, when there is a delay in stencil release, at a certain point in time, the screen plate 6 and the material to be printed W1 come into contact at the predetermined position S1, so at that point in time, the height of the screen plate 6 decreases sharply. In the example shown in Figure 8, it can be seen that at time td, the height of the screen plate 6 decreases sharply in change G2. Therefore, in the example shown in Figure 8, it is understood that a delay in stencil release began at time td.

[0087] Next, in both cases, the change in the height position of the screen plate 6 over time under ideal conditions for stencil separation was calculated by simulation. Figure 9 is a graph showing the change in the height position of the screen plate 6 over time, as determined by simulation. In the graph shown in Figure 9, the horizontal axis represents time, and the vertical axis represents the height position of the screen plate 6. In Figure 9, change G3 is a graph showing the ideal state of change G1, and change G4 is a graph showing the ideal state of change G2. Comparing change G3 and change G1, there is no significant difference between the outlines of change G3 and change G1, and the trend of a gradual decrease from time t2 to time t3 is consistent. On the other hand, comparing change G4 and change G2, it can be seen that the outlines of change G4 and change G2 differ from each other because there is a delay in stencil separation at time td in change G2.

[0088] As described above, when there is a delay in the release of the print, the height of the screen plate 6 decreases sharply at a certain point in time. In other words, when there is a delay in the release of the print, the variation in the height of the screen plate 6 is greater compared to when the release of the print is good. From the above, it can be understood that the state of the release of the print from the screen plate 6 can be reliably reflected in the change in the height of the screen plate 6 over time.

[0089] As described above, this printing method is a screen printing method for printing paste P1 onto a substrate W1, and includes preparing a screen plate 6, a squeegee 16, and a measuring instrument 23 for measuring the distance to the screen plate 6; positioning the screen plate 6 at a distance from the substrate W1; placing paste P1 on the screen plate 6; printing paste P1 onto the substrate W1 by sliding the squeegee 16 along the screen plate 6 while pressing it against the screen plate 6; measuring the distance to the screen plate 6 at a predetermined position S1 behind the squeegee 16 in the sliding direction of the squeegee 16 using the measuring instrument 23; and acquiring data on the height position of the screen plate 6 based on the measurement results.

[0090] In this printing method, the acquired data on the height position of the screen plate 6 corresponds to the data on the height position of the screen plate 6 at a predetermined position S1 behind the squeegee 16 in the sliding direction of the squeegee 16. Therefore, in this printing method, the state of screen separation can be determined.

[0091] In this printing method, data acquisition includes acquiring data on the change in the height position of the screen plate 6 over time. In this printing method, the acquired data on the change in the height position of the screen plate 6 over time corresponds to the data on the change in the height position of the screen plate 6 over time at a predetermined position S1. Therefore, in this printing method, the state of screen separation can be reliably determined.

[0092] This printing method includes extracting characteristic quantities of the screen plate 6's separation from data on the temporal change in the height position of the screen plate 6. In this printing method, the degree of ink separation from the screen plate 6 is extracted as a quantitative value called a feature. Therefore, the degree of ink separation can be quantitatively determined using this printing method.

[0093] This printing method includes determining the quality of screen printing using screen plate 6 based on the characteristics of the screen plate 6's separation from the screen plate. In this printing method, the quality of screen printing is determined based on quantitative values. Therefore, this printing method ensures that the quality of screen printing is appropriately determined.

[0094] This printing method includes adjusting at least one of the following based on the characteristic quantity of the screen release of the screen plate 6: the pressure applied by the squeegee 16 to the screen plate 6, or the distance between the material to be printed W1 and the screen plate 6. In this printing method, at least one of the above pressing force or the above spacing is adjusted based on the characteristic quantity of the screen release of the screen plate 6. Therefore, a decrease in print quality can be suppressed in this printing method.

[0095] In this printing method, the measurement process includes measuring the distance from the squeegee 16 to the screen plate 6 at a distance of 5 mm to 8 mm. This printing method allows for a more reliable assessment of the ink separation from the printing plate.

[0096] In this printing method, performing a measurement involves moving the measuring instrument 23 together with the squeegee 16 in the sliding direction of the squeegee 16. In this printing method, the distance to the screen plate 6 at a predetermined position S1 is accurately measured even while the squeegee 16 is sliding.

[0097] In this printing method, the measurement process involves using a laser displacement meter 23b as the measuring instrument 23, irradiating the screen plate 6 with laser light, and measuring the displacement of the screen plate 6. In this printing method, the distance to the screen plate 6 at a predetermined position S1 is easily measured.

[0098] While embodiments of the present invention have been described above, the present invention is not necessarily limited to the embodiments described above, and various modifications are possible without departing from the spirit of the invention.

[0099] In the screen printing apparatus 1, the controller 24 does not need to acquire data on the change in the height position of the screen plate 6 over time. As described above, the screen printing apparatus 1 can reliably know the status of screen separation, thanks to the controller 24 acquiring data on the change in the height position of the screen plate 6 over time.

[0100] In the screen printing apparatus 1, the controller 24 does not need to extract characteristic quantities of the screen plate 6's separation from the data of the time-dependent change in the height position of the screen plate 6. The controller 24 extracts characteristic quantities of the screen plate 6's separation from data on the temporal change in the height position of the screen plate 6, allowing the screen printing apparatus 1 to quantitatively know the state of screen plate separation, as described above.

[0101] In the screen printing apparatus 1, the controller 24 does not need to determine the quality of screen printing using the screen plate 6 based on the characteristic quantities of the screen plate 6's separation properties. The controller 24 determines the quality of the screen printing using the screen plate 6 based on the characteristics of the screen plate 6's separation from the screen plate 6, and the screen printing apparatus 1 appropriately determines the quality of the screen printing as described above.

[0102] In the screen printing apparatus 1, the controller 24 does not need to control at least one of the pressing force adjustment mechanism 14 or the spacing adjustment mechanism 10 to adjust at least one of the pressing force of the squeegee against the screen plate 6 or the spacing between the material to be printed W1 and the screen plate 6 based on the characteristic quantity of the screen plate 6's separation from the plate. The screen printing apparatus 1, in which the controller 24 controls at least one of the pressing force adjustment mechanism 14 or the spacing adjustment mechanism 10 to adjust at least one of the pressing force of the squeegee 16 against the screen plate 6 or the spacing between the material to be printed W1 and the screen plate 6 based on the characteristic quantity of the screen plate 6's separation from the screen plate, can suppress a decrease in print quality as described above.

[0103] In the screen printing apparatus 1, the predetermined position S1 does not have to be located at a distance of 5 mm or more and 8 mm or less from the squeegee 16. As described above, a screen printing apparatus 1 where the predetermined position S1 is located 5 mm to 8 mm away from the squeegee 16 can more reliably determine the state of screen separation.

[0104] In the screen printing apparatus 1, the measuring instrument 23 does not need to move together with the squeegee 16 in the sliding direction of the squeegee 16. As described above, the screen printing apparatus 1, with the measuring instrument 23 moving together with the squeegee 16 in the sliding direction of the squeegee 16, appropriately measures the distance to the screen plate 6 at a predetermined position S1 even while the squeegee 16 is sliding.

[0105] In the screen printing apparatus 1, the measuring instrument 23 does not necessarily have to include a laser displacement meter 23b that irradiates the screen plate 6 with laser light to measure the displacement of the screen plate. The screen printing apparatus 1, which includes a laser displacement meter 23b that irradiates the screen plate 6 with laser light to measure the displacement of the screen plate 6, conveniently measures the distance to the screen plate 6 at a predetermined position S1, as described above.

[0106] In the above printing method, acquiring data does not necessarily involve acquiring data on the change in the height position of the screen plate 6 over time. In a printing method where data acquisition includes acquiring data on the change in the height position of the screen plate 6 over time, the condition of plate separation can be reliably determined, as described above.

[0107] The above printing method does not necessarily have to include extracting characteristic quantities of the screen plate 6's separation from data on the temporal change in the height position of the screen plate 6. In a printing method that includes extracting characteristic quantities of screen separation from the screen plate 6 from data on the temporal change in the height position of the screen plate 6, the state of screen separation can be quantitatively determined, as described above.

[0108] The above printing method does not necessarily have to include determining the quality of screen printing using screen plate 6 based on the characteristics of the screen plate 6's separation from the screen plate 6. In a printing method that includes determining the quality of screen printing using screen plate 6 based on the characteristics of the screen plate 6's separation from the screen plate, the quality of the screen printing is appropriately determined, as described above.

[0109] The above printing method does not necessarily include adjusting the pressing force of the squeegee 16 against the screen plate 6, or at least the distance between the material to be printed W1 and the screen plate 6, based on the characteristic quantity of the screen plate 6's release properties. In a printing method that includes adjusting either the pressing force of the squeegee 16 against the screen plate 6, or at least the distance between the material to be printed W1 and the screen plate 6, based on the characteristic quantity of the screen plate's release properties, the deterioration of print quality can be suppressed, as described above.

[0110] In the above printing method, the measurement does not necessarily have to include measuring the distance from the squeegee 16 to the screen plate 6 at a distance of 5 mm to 8 mm. In a printing method in which the measurement involves measuring the distance from the squeegee 16 to the screen plate 6 at a distance of 5 mm to 8 mm, the condition of screen separation can be determined more reliably, as described above.

[0111] In the above printing method, the measurement does not necessarily involve moving the measuring instrument 23 together with the squeegee 16 in the sliding direction of the squeegee 16. In a printing method in which the measurement involves moving the measuring instrument 23 together with the squeegee 16 in the sliding direction of the squeegee 16, the distance to the screen plate 6 at a predetermined position S1 is appropriately measured even while the squeegee 16 is sliding, as described above.

[0112] In the above printing method, the measurement does not necessarily have to include using a laser displacement meter 23b as the measuring instrument 23, irradiating the screen plate 6 with laser light, and measuring the displacement of the screen plate 6. In a printing method in which the measurement is performed using a laser displacement meter 23b as the measuring instrument 23, and by irradiating the screen plate 6 with laser light to measure the displacement of the screen plate 6, the distance to the screen plate 6 at a predetermined position S1 can be easily measured as described above.

[0113] In the embodiment described above, the controller 24 has an extraction unit 26, but the controller 24 does not necessarily have to have an extraction unit 26. In this case, the controller 24 may be connected to an external server via a predetermined communication network, for example. The acquisition unit 25 of the controller 24 outputs data on the change in the height position of the screen plate 6 over time to the external server, and the extraction of the screen plate 6's separation may be performed on the external server.

[0114] In the embodiment described above, the screen printing apparatus 1 is equipped with one measuring instrument 23, but the number of measuring instruments 23 equipped in the screen printing apparatus 1 is not limited to the number described above. That is, the screen printing apparatus 1 may be equipped with multiple measuring instruments 23. For example, the screen printing apparatus 1 may be equipped with three measuring instruments 23. In this case, the three measuring instruments 23 may be arranged adjacent to each other in the third direction D3.

[0115] As can be seen from the descriptions of the embodiments described above, this specification includes disclosures of the following embodiments. (Note 1) A table on which the printed material is placed, A screen plate positioned at a distance from the aforementioned printed material, A squeegee slides on the screen plate while being pressed against the screen plate, A measuring instrument for measuring the distance from the squeegee to the screen plate at a predetermined position behind the squeegee in the sliding direction of the squeegee, A screen printing apparatus comprising a controller that acquires data on the height position of the screen plate based on the output from the measuring instrument. (Note 2) The controller is a screen printing apparatus as described in Appendix 1, which acquires data on the change in the height position over time. (Note 3) The screen printing apparatus as described in Appendix 2, wherein the controller extracts characteristic quantities of screen plate separation from the data of the change in height position over time. (Note 4) The screen printing apparatus described in Appendix 3, wherein the controller determines the quality of screen printing using the screen plate based on the feature quantities. (Note 5) The system further comprises at least one of a first mechanism for adjusting the pressing force of the squeegee against the screen plate, or a second mechanism for adjusting the distance between the material to be printed and the screen plate. The screen printing apparatus according to Appendix 3 or 4, wherein the controller controls the first mechanism or the second mechanism to adjust at least one of the pressing force or the interval based on the feature quantity. (Note 6) The screen printing apparatus described in any one of the appendices 1 to 5, wherein the predetermined position is located 5 mm to 8 mm away from the squeegee. (Note 7) The measuring instrument moves together with the squeegee in the sliding direction of the squeegee, and is part of the screen printing apparatus described in any one of the appendices 1 to 6. (Note 8) The aforementioned measuring instrument is a screen printing apparatus as described in any one of the appendices 1 to 7, which includes a laser displacement meter that irradiates the screen plate with laser light to measure the displacement of the screen plate. (Note 9) A screen printing method for printing paste onto a substrate, Prepare the screen, the squeegee, and the measuring instrument to measure the distance to the screen. The aforementioned screen plate is positioned at a distance from the material to be printed, The paste is placed on the aforementioned screen plate, The paste is printed onto the substrate by pressing the squeegee against the screen plate and sliding it along the screen plate. Using the aforementioned measuring instrument, the distance to the screen plate at a predetermined position behind the squeegee in the sliding direction of the squeegee is measured. A screen printing method comprising obtaining data on the height position of the screen plate based on the results of the measurement. (Note 10) The screen printing method described in Appendix 9, wherein acquiring the aforementioned data includes acquiring data on the change in the height position over time. (Note 11) The screen printing method according to Appendix 10, further comprising extracting characteristic quantities of the screen plate's separation from the data of the change in height position over time. (Note 12) The screen printing method according to Appendix 11, further comprising determining the quality of screen printing using the screen plate based on the aforementioned feature quantities. (Note 13) The screen printing method according to Appendix 11 or 12, further comprising adjusting, based on the aforementioned feature quantities, the pressing force of the squeegee against the screen plate, or at least one of the distance between the workpiece to be printed and the screen plate. (Note 14) The screen printing method described in any one of the appendices 9 to 13, wherein the measurement includes measuring the distance from the squeegee to the screen plate at a distance of 5 mm to 8 mm. (Note 15) The screen printing method according to any one of the appendices 9 to 14, wherein performing the measurement includes moving the measuring instrument together with the squeegee in the sliding direction of the squeegee. (Note 16) The screen printing method described in any one of the appendices 9 to 15, wherein the measurement is performed using a laser displacement meter as the measuring instrument, and the displacement of the screen plate is measured by irradiating the screen plate with laser light. [Explanation of Symbols]

[0116] 1...Screen printing device, 2...Table, 6...Screen plate, 16...Squeegee, 23...Measuring instrument, 23b...Laser displacement meter, 24...Controller, P1...Paste, S1...Designated position, W1...Material to be printed.

Claims

1. A table on which the printed material is placed, A screen plate positioned at a distance from the aforementioned printed material, A squeegee slides on the screen plate while being pressed against the screen plate, A measuring instrument for measuring the distance from the squeegee to the screen plate at a predetermined position behind the squeegee in the sliding direction of the squeegee, A controller that acquires data on the height position of the screen plate based on the output from the measuring instrument, The system comprises at least one of a first mechanism for adjusting the pressing force of the squeegee against the screen plate, or a second mechanism for adjusting the distance between the material to be printed and the screen plate. The aforementioned controller, By acquiring data on the change in the aforementioned height position over time, From the data of the change in height position over time, a feature quantity of the screen plate separation, which indicates the variation in the height position of the screen plate, is extracted. A screen printing apparatus that controls the first mechanism or the second mechanism to adjust at least one of the pressing force or the interval based on the aforementioned feature quantities.

2. The screen printing apparatus according to claim 1, wherein the controller determines the quality of screen printing using the screen plate based on the feature quantities.

3. The screen printing apparatus according to claim 1 or 2, wherein the predetermined position is located at a distance of 5 mm or more and 8 mm or less from the squeegee.

4. The screen printing apparatus according to claim 1 or 2, wherein the measuring instrument moves together with the squeegee in the sliding direction of the squeegee.

5. The screen printing apparatus according to claim 1 or 2, wherein the measuring instrument includes a laser displacement meter that irradiates the screen plate with laser light to measure the displacement of the screen plate.

6. A screen printing method for printing paste onto a substrate, Prepare the screen plate, the squeegee, and the measuring instrument to measure the distance to the screen plate. The aforementioned screen plate is positioned at a distance from the material to be printed, The paste is placed on the aforementioned screen plate, The paste is printed onto the substrate by pressing the squeegee against the screen plate and sliding it along the screen plate. Using the aforementioned measuring instrument, the distance to the screen plate at a predetermined position behind the squeegee in the sliding direction of the squeegee is measured. Based on the results of the above measurement, data on the change in the height position of the screen plate over time will be obtained, From the data of the change in height position over time, a characteristic quantity of the screen plate separation that indicates the variation in the height position of the screen plate is extracted, A screen printing method comprising adjusting, based on the aforementioned feature quantities, the pressing force of the squeegee against the screen plate, or at least one of the distance between the material to be printed and the screen plate.

7. The screen printing method according to claim 6, further comprising determining the quality of screen printing using the screen plate based on the aforementioned feature quantities.

8. The screen printing method according to claim 6 or 7, wherein the measurement includes measuring the distance from the squeegee to the screen plate at a distance of 5 mm or more and 8 mm or less.

9. The screen printing method according to claim 6 or 7, wherein performing the measurement includes moving the measuring instrument together with the squeegee in the sliding direction of the squeegee.

10. The screen printing method according to claim 6 or 7, wherein the measurement is performed using a laser displacement meter as the measuring instrument, and the displacement of the screen plate is measured by irradiating the screen plate with laser light.

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