Screen printing machine

Abstract

A screen printer performs printing of a viscous fluid on a substrate using a mask formed with a printing pattern composed of through-holes. The screen printer includes a substrate holding device that holds a substrate, a mask holding device that holds an end portion of a mask at a position above the substrate held by the substrate holding device along an outer periphery of the mask, an air nozzle that can eject air toward a target point on an upper surface of the mask at the position above the substrate, and a displacement measuring device that measures a displacement amount in a vertical direction of one or more measurement target points on the upper surface corresponding to the target point before and after the air is ejected from the air nozzle toward the target point.

Description

Technical Field

[0001] The technology disclosed in this specification relates to screen printing machines. Background Technology

[0002] A screen printing machine is known that fills a viscous fluid into a through-hole of a mask while the mask is held above a substrate. In this machine, if a gap is created between the mask and the substrate during the filling of the through-hole, the viscous fluid may intrude into that gap. The screen printing machine of Patent Document 1 presses the shaft of an actuator against the upper surface of the mask from above. As a result, the mask is displaced downwards toward the substrate depending on the size of the gap formed between the mask and the substrate. The screen printing machine determines the distance between the mask and the substrate based on the amount of displacement of the actuator shaft (i.e., the mask).

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Utility Model Application Publication No. 04-100849 Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] In the aforementioned screen printing machine, to measure the distance between the mask and the substrate, the actuator shaft is pressed against the upper surface of the mask. Therefore, the shaft may cause damage to the upper surface of the mask. This specification provides a technique that reduces damage to the upper surface of the mask when measuring the distance between the mask and the substrate, compared to existing technologies.

[0008] Methods for solving problems

[0009] The screen printing machine disclosed in this specification uses a mask with a printing pattern formed by through holes to print a viscous fluid onto a substrate. The screen printing machine includes: a substrate holding device for holding the substrate; a mask holding device for holding an end of the mask along its outer periphery at a position above the substrate held by the substrate holding device; an air nozzle capable of ejecting air toward a target point on the upper surface of the mask held above the substrate; and a displacement measuring device for measuring the vertical displacement of one or more target points on the upper surface corresponding to the target point before and after the air is ejected from the air nozzle toward the target point.

[0010] According to the screen printing machine described above, the mask is displaced by air ejected from an air nozzle without direct contact with the upper surface of the mask. Therefore, the vertical displacement of the measurement point on the upper surface of the mask can be measured in a non-contact manner. When measuring the distance between the mask and the substrate, the screen printing machine described above can reduce damage to the upper surface of the mask. Attached Figure Description

[0011] Figure 1 This is a side view of the screen printing machine according to the first embodiment.

[0012] Figure 2 yes Figure 1 An enlarged view of the area within the dashed line II in the diagram.

[0013] Figure 3 This is a top view of the mask of the screen printing machine configured in the first embodiment.

[0014] Figure 4 This is a structural diagram of the control device of the screen printing machine according to the first embodiment.

[0015] Figure 5 This is a flowchart of the substrate printing process performed by the control device in the first embodiment.

[0016] Figure 6 This is a flowchart of the substrate printing process performed by the control device in the second embodiment. Detailed Implementation

[0017] The main features of the embodiments described below are listed. It should be noted that the technical elements described below are independent technical elements, which exert their technical usefulness through individual or various combinations, and are not limited to the combinations described in the claims at the time of application.

[0018] (Feature 1) In the above-mentioned screen printing machine, the one or more measurement object points may include the target point.

[0019] When air is ejected from the nozzle towards the target point, the vertical displacement at the target point tends to be larger compared to points surrounding the target point. Based on this structure, the vertical displacement can be measured more easily than structures that measure the vertical displacement of points surrounding the target point.

[0020] (Feature 2) The screen printing machine described above may also include: a substrate lifting device that lifts the substrate holding device during the printing of the viscous fluid onto the substrate; and a lifting amount determining unit that determines the lifting amount of the substrate holding device. In this case, the lifting amount determining unit may determine the lifting amount based on the displacement of the one or more measurement target points measured by the displacement measuring device.

[0021] With this structure, the substrate can be brought close to the mask based on the displacement of one or more measurement points. Therefore, when printing viscous fluids onto the substrate, the distance between the substrate and the mask can be reduced.

[0022] (Feature 3) The screen printing machine described above may also include an ejection amount determination unit that determines the ejection amount of air ejected from the air nozzle. In this case, the target point may include a first target point and a second target point different from the first target point. Alternatively, the ejection amount determination unit may determine the ejection amount of air for the second target point as a second ejection amount different from the first ejection amount of air for the first target point. The displacement measuring device may also measure the vertical displacement of a first measuring object point corresponding to the first target point, and measure the vertical displacement of a second measuring object point corresponding to the second target point.

[0023] Based on this structure, the amount of air ejected can be adjusted according to the location of the target point. Therefore, it is possible to determine the appropriate amount of air ejected for the target point.

[0024] (Feature 4) The screen printing machine described above may also include an opening area determining unit that determines the opening area of ​​the nozzle outlet of the air nozzle. In this case, the target point may include a first target point and a second target point different from the first target point. The opening area determining unit may also determine the opening area of ​​the nozzle outlet for the second target point as a second opening area different from the first opening area of ​​the nozzle outlet for the first target point. The displacement measuring device may also measure the vertical displacement of a first measuring object point corresponding to the first target point, and measure the vertical displacement of a second measuring object point corresponding to the second target point.

[0025] Based on this structure, the opening area can be adjusted according to the location of the target point. Therefore, it is possible to determine the appropriate opening area for the location of the target point.

[0026] (Feature 5) The screen printing machine described above may also include an operation control unit for controlling the operation of the substrate holding device, and the substrate holding device may also have a clamping member for holding the end of the substrate. In this case, if the displacement of the measured target point measured by the displacement measuring device exceeds a predetermined threshold, the operation control unit may, after releasing the end of the substrate, cause the clamping member to hold the end of the substrate again.

[0027] When the clamping member holds the end of the substrate, the substrate may sometimes deflect. In this case, the distance between the mask and the substrate tends to increase. As a result, the vertical displacement of the measurement target point increases. According to this structure, if the displacement exceeds a predetermined threshold, the clamping member releases the end of the substrate and re-grips the end of the substrate. Thus, substrate deflection can be eliminated.

[0028] (Feature 6) The screen printing machine described above may also include: a squeegee for filling the viscous fluid into the through-hole of the mask; and a squeegee action determining unit for determining the force that presses the squeegee against the upper surface of the mask and the speed at which the squeegee moves along the upper surface of the mask. In this case, the squeegee action determining unit may also determine at least one of the force and the speed based on the displacement of the measurement target point measured by the displacement measuring device.

[0029] Based on this structure, the action of the squeegee (i.e., at least one of force and velocity) is determined according to the amount of displacement. Thus, the screen printing machine is able to perform printing at a distance suitable for the mask and substrate.

[0030] (First embodiment)

[0031] Reference Figures 1 to 3 The structure of the screen printing machine 10 (hereinafter referred to as the printing machine 10) according to the first embodiment will be described. The printing machine 10 is a device that uses a mask 20 to print solder paste 38, which is a viscous fluid, onto a circuit board 2 (hereinafter referred to as the substrate 2), which is the workpiece, and then transports it to an electronic component mounting device, which is a subsequent process. Hereinafter, the -Y direction in the drawings will be represented as the front side. In addition, the +Y direction will be represented as the rear side, the +Z direction as the upper side, and the -Z direction as the lower side.

[0032] Figure 1 This shows a side view of the printing press 10. The printing press 10 includes a scraper unit 30, a unit drive device 12, a mask holding device 24, a substrate holding device 14, a gap measuring unit 40, a control device 50, a high-pressure tank 4, and an adjusting valve 6 within a box-shaped housing. Additionally, in... Figure 1 In the image, the casing of the printing press 10 is depicted in perspective, but it is actually composed of six plates that divide the interior of the printing press 10.

[0033] The squeegee unit 30 includes a squeegee 36, an angle adjustment device 34, and a lifting device 32. The squeegee 36 is a flat plate with a rectangular shape extending along the X-axis. In this embodiment, the squeegee 36 is a metal squeegee, but in variations, it may be a polyurethane squeegee, for example. The angle adjustment device 34 adjusts the posture of the squeegee 36 relative to the substrate 2 (the angle between the upper surface of the substrate 2 and the squeegee 36). The lifting device 32 moves the squeegee 36 in the vertical direction. Additionally, the lifting device 32 moves the squeegee 36 up and down relative to the substrate 2 to adjust the pressure (hereinafter referred to as printing pressure) pressing the squeegee 36 onto the mask 20.

[0034] The substrate holding device 14 includes a pair of clamping members 16F and 16S. The clamping members 16F and 16S hold the substrate 2 from the front and rear. Thus, the substrate 2 is fixed to the substrate holding device 14. Below the substrate holding device 14, a substrate lifting device 15 and a substrate transport device 16 are arranged. The substrate lifting device 15 has a servo motor (not shown). The substrate lifting device 15 raises and lowers the substrate holding device 14 by operating the servo motor. Similarly, the substrate transport device 17 has a servo motor (not shown), which, by operating the servo motor, transports the substrate 2 before printing to the substrate holding device 14, and transports the substrate 2 after printing from the substrate holding device 14 in the +X direction (i.e., ...). Figure 1 (Transport the paper from the front direction).

[0035] The unit drive device 12 causes the scraper unit 30 to move along a pair of guide rails in the back-and-forth direction of the printing press 10 (i.e., Figure 1 The scraper unit 30 moves in the left-right direction on the paper. The detailed structure of the unit drive device 12 that moves the scraper unit 30 in the front-back direction is known, so it is omitted here.

[0036] Especially as Figure 3 As shown, the mask holding device 24 includes a frame disposed along the outer periphery of the mask 20. The frame of the mask holding device 24 holds the end of the mask 20. Therefore, when solder paste 38 is filled into the through-hole 22 of the mask 20 by the scraper unit 30, positional displacement of the mask 20 can be suppressed. A plurality of holding mechanisms 26 are provided in the mask holding device 24. The mask holding device 24, holding the end of the mask 20, is held above the substrate 2 by the plurality of holding mechanisms 26.

[0037] Multiple through holes 22 are formed in the mask 20. The multiple through holes 22 are arranged according to the printing pattern 21. When solder paste 38 is pressed onto the upper surface of the mask 20 by the squeegee 36, the solder paste 38 adheres to the substrate 2 through the multiple through holes 22 (i.e., the printing pattern 21). Thus, solder paste 38 is printed on the upper surface of the substrate 2 according to the printing pattern 21.

[0038] The gap measuring unit 40 is used to measure the distance (gap) between the mask 20 and the upper surface of the substrate 2 during the printing of solder paste 38 onto the substrate 2. The gap measuring unit 40 includes an air nozzle 44 (hereinafter referred to as nozzle 44), a displacement sensor 46, a lifting device 42, and a drive device 48. The nozzle 44 is connected to a high-pressure tank 4 via an adjustment valve 6. Compressed air is stored in the high-pressure tank 4. When the adjustment valve 6 is opened, air from the high-pressure tank 4 is ejected from the nozzle 44 onto the mask 20. Furthermore, the amount of air ejected from the nozzle 44 onto the mask 20 is varied according to the opening degree of the adjustment valve 6.

[0039] The displacement sensor 46 is a so-called optical sensor. Internally, the displacement sensor 46 has a light-projecting section and a light-receiving section. The displacement sensor 46 irradiates a laser beam from the light-projecting section onto the object being measured. The irradiated light is reflected by the object being measured, and the reflected light is incident on the light-receiving section. The displacement sensor 46 detects the displacement of the object being measured based on the change in the position of the light incident on the light-receiving section. Furthermore, in a modified example, the displacement sensor 46 may also be an ultrasonic sensor, for example.

[0040] The lifting device 42 moves the nozzle 44 and the displacement sensor 46 in the vertical direction. The driving device 48 moves the nozzle 44 and the displacement sensor 46 in the X direction. In addition, the gap measuring unit 40 can be moved in the front-back direction (Y direction) of the printing press 10 by means of the unit driving device 12. That is, the gap measuring unit 40 can move the nozzle 44 and the displacement sensor 46 along the upper surface of the mask 20.

[0041] Reference Figure 2 The nozzle 44 and displacement sensor 46 of the gap measuring unit 40 will be described. The nozzle 44 has a cylindrical shape extending in the vertical direction. An opening 47 and an opening adjustment part 45 are provided at the lower end of the nozzle 44. The opening adjustment part 45 is a mechanism for changing the area of ​​the opening 47 and has a wall that defines the opening 47 of the nozzle 44. When the wall of the opening adjustment part 45 moves towards the center of the nozzle 44, the area of ​​the opening 47 of the nozzle 44 decreases. When the wall of the opening adjustment part 45 moves away from the center of the nozzle 44, the area of ​​the opening 47 increases.

[0042] As described above, the mask 20 is held above the substrate 2 by the mask holding device 24. Furthermore, the substrate 2 is positioned below the mask 20 with its ends held by a pair of clamping members 16F and 16S of the substrate holding device 14. Here, the mask 20 is, for example, a thin film of less than 1 mm, thus allowing for localized vertical displacement. Furthermore, the substrate 2 also has a relatively thin flat plate shape, so when the ends of the substrate 2 are held by the clamping members 16F and 16S, it may deform, for example, by bending the central portion upwards. As a result, ... Figure 2As shown, a gap of length C1, which varies depending on the location, may be generated between the lower surface 20D of the mask 20 and the upper surface 2U of the substrate 2.

[0043] If a large gap is created between the lower surface 20D of the mask 20 and the upper surface 2U of the substrate 2, the solder paste 38 will enter the gap when filling the through hole 22. As a result, poor printing may occur, where the solder paste 38 is printed in an unwanted location on the substrate 2.

[0044] Before printing is performed by the printing press 10, i.e., before the squeegee 36 moves backward, the gap measuring unit 40 measures the distance between the lower surface 20D of the mask 20 and the upper surface 2U of the substrate 2. Specifically, the gap measuring unit 40 sprays air 60 through the nozzle 44 towards the target point PB on the upper surface 20U of the mask 20. When a gap exists between the lower surface 20D of the mask 20 and the upper surface 2U of the substrate 2, the mask 20 is displaced downward by the length C1 of the gap, and the lower surface 20D of the mask 20 comes into contact with the upper surface 2U of the substrate 2. That is, the amount of displacement of the mask 20 is called the length C1 of the gap. The displacement sensor 46 measures the displacement of the target point PB before the air 60 is sprayed and the target point PA after the air 60 is sprayed. Thus, the gap measuring unit 40 can measure the length C1 of the gap. The gap measuring unit 40 sends the measured length C1 of the gap to the control device 50.

[0045] For example, such as Figure 3 As shown, in this embodiment, the gap measuring unit 40 measures the length of the gap at target points P1 to P9. Target points P1, P3, P6, and P8 are located at the four corners of the mask 20. Target point P4 is located at the center of the mask 20. Target points P2, P5, P7, and P9 are located at the center of each side of the mask 20.

[0046] Reference Figure 4 The structure of the control device 50 will be described below. The control device 50 is composed of a computer having a memory 51 and a CPU 54. The control device 50 is communicatively connected to each of the devices 6 to 45 of the printing press 10.

[0047] The memory 51 is composed of a storage medium such as an HDD. The memory 51 stores the printing program 52. The printing program 52 is a program for printing solder paste 38 on the substrate 2 using the mask 20. The printing program 52 includes a target point table T1, threshold displacement amounts Dth1 and Dth2, and printing settings 53.

[0048] In the target point table T1, the coordinates, ejection volume, and opening area of ​​each target point P1 to P9 are stored in a correlated manner. The target point table T1 is used to determine the ejection volume of air 60 and the opening area of ​​nozzle 44 at each target point P1 to P9. The target point table T1 is pre-stored in the printing program 52, but the operator can also change, add, or delete the coordinates of the target points based on the actual printing results. Furthermore, the operator can also change the ejection volume and the opening area.

[0049] In the target point table T1 of this embodiment, a spray volume V1 is set for target points P1~P3 and P6~P8. On the other hand, a spray volume V2 is set for target points P4, P5, and P9. For example... Figure 3 As shown, target points P4, P5, and P9 are located in the front-back direction of substrate 2 (i.e., Figure 3 The center of the substrate 2 (in the left-right direction). As described above, the front-back end of the substrate 2 is held by a pair of clamping members 16F and 16S, so the center portion in the front-back direction can easily be displaced upwards. Therefore, at target points P4, P5, and P9, the distance between the upper surface 2U of the substrate 2 and the lower surface 20D of the mask 20 (i.e., the gap length C1) can easily become smaller. On the other hand, at target points P1~P3 and P6~P8, compared with target points P4, P5, and P9, the gap length C1 can easily become larger. Therefore, the ejection amount V1 is set to be larger than the ejection amount V2. As a result, at the front-back end of the substrate 2 with a gap length C1, by using air 60 with an ejection amount V1 larger than the ejection amount V2, the mask 20 can be sufficiently displaced until the lower surface 20D of the mask 20 abuts against the upper surface 2U of the substrate 2. As a result, the displacement sensor 46 can accurately measure the gap length C1. That is, the printing press 10 can accurately measure the gap C1 by changing the ejection volume V1 and V2 according to the position of the target points P1~P9.

[0050] Similarly, in the target point table T1 of this embodiment, an opening area A1 is provided at target points P1~P3 and P6~P8. On the other hand, an opening area A2 is provided at target points P4, P5 and P9. The opening area A1 is set to be larger than the opening area A2. As a result, at the end of the substrate 2 in the front-rear direction where the gap length C1 is larger, the mask 20 can be sufficiently displaced until the lower surface 20D of the mask 20 abuts against the upper surface 2U of the substrate 2 by air 60 ejected through the opening area A1 which is larger than the opening area A2. As a result, the distance between the upper surface 2U of the substrate 2 and the lower surface 20D of the mask 20 can be accurately measured. That is, by further changing the opening areas A1 and A2 according to the positions of the target points P1~P9, the printing press 10 can accurately measure the gap length C1.

[0051] Threshold displacement Dth1 is a threshold used to determine whether the control device 50 performs a reset of the pair of clamping members 16F and 16S during the substrate printing process described later. Threshold displacement Dth2 is a threshold used to determine whether the control device 50 performs a change to the printing setting 53 during the substrate printing process. Each threshold Dth1 and Dth2 is pre-stored in the printing program 52, but can also be changed by the operator.

[0052] The printing settings 53 include printing pressure F1 and printing speed S1. These are values ​​pre-stored in the printing program 52. The control device 50 can adjust the printing pressure via the lifting device 32 of the squeegee unit 30. The printing speed is the speed at which the squeegee unit 30 advances backward while filling the through-hole 22 of the mask 20 with solder paste 38. The control device 50 can adjust the printing speed via the unit drive device 12.

[0053] CPU 54 performs various processes according to printing program 52. As a result, CPU 54 functions as rise amount determination unit 55, ejection amount determination unit 56, opening area determination unit 57, motion control unit 58, and scraper motion determination unit 59.

[0054] Reference Figure 5 The substrate printing process performed by the CPU 54 of the control device 50 of the printing press 10 will be described. The substrate printing process begins after the mask 20 is held in the mask holding device 24 and the substrate 2 is held in the substrate holding device 14, according to the operator's printing start instruction.

[0055] In S10, the CPU 54, based on the target point table T1, moves the nozzle 44 and the displacement sensor 46 in the order of target points P1 to P9. When the nozzle 44 and the displacement sensor 46 are moved to each target point P1 to P9, the CPU 54 causes the nozzle 44 to spray air 60 towards each target point P1 to P9. At this time, as described above, the CPU 54, based on the target point table T1, changes the spray volume V1 or V2 and the opening area A1 or A2 according to the target points P1 to P9.

[0056] In S12, CPU54 obtains the displacement of each target point P1~P9 before and after the ejected air 60 from displacement sensor 46.

[0057] In S20, the CPU54 compares each displacement amount obtained from the displacement sensor 46 with the threshold displacement amount Dth1. If the displacement amount does not include any displacement amount exceeding the threshold displacement amount Dth1 (S20: No), the CPU54 proceeds to S22; if the displacement amount includes any displacement amount exceeding the threshold displacement amount Dth1 (S20: Yes), the CPU54 proceeds to S24.

[0058] In step S24, the CPU 54 resets the pair of clamping members 16F and 16S. Specifically, the CPU 54 releases the front-rear ends of the substrate 2 from the pair of clamping members 16F and 16S. Then, the CPU 54 re-clamps the front-rear ends of the substrate 2 with the pair of clamping members 16F and 16S. This eliminates deformation of the substrate 2 caused by the clamping of the pair of clamping members 16F and 16S. As a result, the length C1 of the aforementioned gap can be reduced.

[0059] In step S22, the CPU 54 adjusts the height of the substrate holding device 14 based on the displacement amounts of each target point P1 to P9 obtained from the displacement sensor 46 in step S12. For example, the CPU 54 raises the substrate holding device 14 by the substrate lifting device 15 to the maximum displacement amount obtained from the displacement sensor 46 in step S12. As a result, when solder paste 38 is printed onto the substrate 2, the lower surface 20D of the mask 20 can be brought into contact with the upper surface 2U of the substrate 2. Consequently, the aforementioned printing defects can be suppressed. Furthermore, in a modified example, the CPU 54 can also raise the substrate holding device 14 to the average value of the displacement amounts of each target point P1 to P9 obtained from the displacement sensor 46 in step S12.

[0060] In S30, CPU54 compares the displacement of each target point P1 to P9 obtained from displacement sensor 46 with the threshold displacement Dth2. If the displacement does not include any displacement exceeding the threshold displacement Dth2 (S30: No), CPU54 skips S32 and proceeds to S40; if the displacement includes any displacement exceeding the threshold displacement Dth2 (S30: Yes), CPU54 proceeds to S32.

[0061] In S32, CPU54 changes the printing settings 53. Specifically, CPU54 increases the printing pressure F1 at the target point where the displacement exceeds the threshold displacement Dth2, and decreases the printing speed S1. Therefore, at the target point where the displacement exceeds the threshold displacement Dth2, the squeegee 36 can press the mask 20 more forcefully against the substrate 2. As a result, printing defects can be suppressed. Furthermore, in a modified example, the printing settings 53 may include at least one of the printing pressure F1 and the printing speed S1. In this case, in S32, CPU54 can change at least one of the printing pressure F1 and the printing speed S1.

[0062] In S40, CPU54 moves the squeegee unit 30 backward based on printing settings 53 to perform printing. As a result, solder paste 38 fills the through holes 22 of the mask 20 and is printed on the substrate 2.

[0063] According to the printing press 10 of this embodiment, the vertical displacement of target points P1 to P9 can be measured without direct contact between the air 60 ejected from the nozzle 44 and the upper surface 20U of the mask 20. Therefore, the printing press 10 can reduce damage to the upper surface 20U of the mask 20 when measuring the distance between the mask 20 and the substrate 2.

[0064] (Second Embodiment)

[0065] Reference Figure 4 and Figure 6 The screen printing machine 10 of the second embodiment will now be described. The screen printing machine 10 of the second embodiment has the same structure as the screen printing machine 10 of the first embodiment described above, but the control device 50 of the screen printing machine 10 of the second embodiment performs a different substrate printing process than the control device 50 of the first embodiment.

[0066] like Figure 4 As shown, the printing process 52 of the second embodiment includes a threshold displacement Dth3 instead of the two threshold displacements Dth1 and Dth2 of the first embodiment. Furthermore, the printing process 52 of the second embodiment includes a response process. The threshold displacement Dth3 is used to determine the threshold displacement in the printing process 52. Figure 6 The threshold for whether the control device 50 performs a response process during the substrate printing process is shown. Response processes include printing setting change processing, clamp reset processing, and stop processing. Printing setting change processing is the process of changing the printing setting 53 mentioned above. Clamp reset processing is the process of resetting the pair of clamps 16F and 16S mentioned above. Print stop processing is the process of stopping the substrate printing process. Before performing the substrate printing process, the operator selects one of the three processes. The selected process is registered as a response process in the printing program 52.

[0067] Reference Figure 6 The substrate printing process performed by the CPU 54 of the screen printing machine 10 in the second embodiment will be described. In S110 and S112, the process is performed in accordance with… Figure 5 The processing is the same as in S10 and S12. In S120, the CPU 54 compares each displacement amount obtained from the displacement sensor 46 with the threshold displacement amount Dth3. If the CPU 54 does not include any displacement amount exceeding the threshold displacement amount Dth3 in each displacement amount (S120: No), it proceeds to S140 to perform the printing process. If the CPU 54 includes any displacement amount exceeding the threshold displacement amount Dth3 in each displacement amount (S120: Yes), it proceeds to S130.

[0068] In S130, the CPU54 determines whether the response process registered in the printing program 52 is a printing stop process. If the response process is a printing stop process (S130: Yes), the CPU54 stops the substrate printing process. As a result, the operator can identify the location that has been displaced beyond the threshold displacement amount Dth3 and correct the substrate or mask at that location.

[0069] If the CPU54 registers a print change processing procedure in the printing program 52 (S130: No), then in S132, the printing settings 53 are changed, and the printing process is executed (S140). In S132, the process is executed... Figure 5 The same processing as S32.

[0070] If the CPU54 registers a clamping reset process in the printed program 52 (S130: No), in S134, a pair of clamping elements 16F and 16S are reset, and the process returns to S120.

[0071] The following describes some points of attention related to the printing press 10 described in the embodiments. For example, the displacement sensor 46 can measure the displacement of four points on the same circumference centered on the target point P when viewing the substrate 2 from above, instead of measuring the displacement of the target point (e.g., P1). By measuring the displacement of the four points corresponding to the target point P, the length C1 of the gap can be accurately measured around the target point P. Furthermore, around the target point P, it is possible to determine which side the substrate 2 or mask 20 is tilted to. In this modified example, the four points are an example of "multiple measurement target points".

[0072] The nozzle 44 of the printing press 10 may, for example, only eject air 60 to a single target point P1. In this case, the ejection amounts V1 and V2 may not be stored in the target point table T1. In this modified example, the "ejection amount determination section" can be omitted. Furthermore, in other modified examples, the opening areas A1 and A2 may not be stored in the target point table T1. In this modified example, the "opening area determination section" can be omitted.

[0073] The substrate holding device 14 may also omit the pair of clamping members 16F and 16S. In this case, the substrate 2 may be disposed on the upper surface of the substrate holding device 14, for example. In this case, the CPU 54 may also omit the processing of S20 and S22. In this modified example, the "action control unit" can be omitted.

[0074] CPU54 may also omit the processing steps S30 and S32. In this variant, the "scraper action determination unit" can be omitted.

[0075] In the target point table T1, instead of the ejection volume or opening area, the ejection pressure can be stored in association with the coordinates of each target point P1 to P9. In this case, for example, the ejection pressure associated with target points P1 to P3 and P6 to P8 can be set to be greater than the ejection pressure associated with target points P4, P5, and P9. In a further variation, in the target point table T1, in addition to the ejection volume and opening area, the ejection pressure can also be stored in association with the coordinates of each target point P1 to P9.

[0076] In the target point table T1 described above, the ejection volume and opening area are varied according to the distance between target points P1~P9 and the pair of clamping members 16F and 16S. Alternatively, the ejection volume and opening area can also be varied, for example, according to the distance between target points P1~P9 and the mask holding device 24. In this case, for example, a large ejection volume V1 and opening area A1 can be set for target points P1~P3 and P5~P9 that are close to the mask holding device 24, and a small ejection volume V2 and opening area A2 can be set for target point P4 that is far from the mask holding device 24.

[0077] The technical elements illustrated in this specification or drawings exert their technical usefulness individually or in various combinations, and are not limited to the combinations recited in the claims at the time of application. Furthermore, the technology illustrated in this specification or drawings simultaneously achieves multiple objectives, and achieving one of these objectives is itself technically useful.

[0078] For example, this specification also discloses the technical idea of ​​changing "the screen printing machine of claim 1" to "the screen printing machine of claim 1 or 2" in claim 3. Similarly, it also discloses the technical idea of ​​changing "the screen printing machine of claim 1" to "the screen printing machine of any one of claims 1 to 3" in claim 4, changing "the screen printing machine of claim 1" to "the screen printing machine of any one of claims 1 to 4" in claim 5, changing "the screen printing machine of claim 1" to "the screen printing machine of any one of claims 1 to 5" in claim 6, and changing "the screen printing machine of claim 1" to "the screen printing machine of any one of claims 1 to 6" in claim 7.

[0079] Explanation of reference numerals in the attached figures

[0080] 2: Circuit board

[0081] 2U, 20U: Top surface

[0082] 4: High-pressure tank

[0083] 6: Adjusting valve

[0084] 10: Screen printing machine

[0085] 12: Unit drive device

[0086] 14: Substrate holding device

[0087] 15: Substrate lifting device

[0088] 16: Substrate handling device

[0089] 16F, 16S: Clamping components

[0090] 17: Substrate handling device

[0091] 20: Mask

[0092] 20D: Lower surface

[0093] 21: Printed Pattern

[0094] 22: Through hole

[0095] 24: Mask holding device

[0096] 26: Maintain the organization

[0097] 30: Scraper Unit

[0098] 32: Lifting device

[0099] 34: Angle adjustment device

[0100] 36: Scraper

[0101] 38: Solder paste

[0102] 40: Gap Measurement Unit

[0103] 42: Lifting device

[0104] 44: Air Nozzle

[0105] 45: Opening adjustment section

[0106] 46: Displacement sensor

[0107] 47: Opening

[0108] 48: Drive unit

[0109] 50: Control device

[0110] 51: Memory

[0111] 52: Printing Process

[0112] 53: Printing Settings

[0113] 54: CPU

[0114] 55: The volume of increase determines the department

[0115] 56: Ejection Volume Determination Department

[0116] 57: Determining part of opening area

[0117] 58: Motion Control Department

[0118] 59: Scraper Action Decision Unit

[0119] 60: Air

[0120] A1, A2: Opening area

[0121] C1: Gap

[0122] Dth1, Dth2, Dth3: Threshold displacement

[0123] F1: Printing pressure

[0124] P1~P9, PA, PB: Target points

[0125] T1: Target Point Table

[0126] V1, V2: Ejection volume

Claims

1. A screen printing machine that uses a mask having a printing pattern formed of through holes to print a viscous fluid onto a substrate, wherein, The screen printing machine has the following features: A substrate holding device for holding the substrate; A mask holding device holds the end of the mask along its outer periphery at a position above the substrate held by the substrate holding device; An air nozzle is capable of ejecting air toward a target point on the upper surface of the mask, which is positioned above the substrate. and The displacement measuring device measures the vertical displacement of one or more target points on the upper surface corresponding to the target point before and after air is ejected from the air nozzle toward the target point. The screen printing machine also includes an action control unit that controls the movement of the substrate holding device. The substrate holding device has a clamping member that holds the end of the substrate. When the displacement of the measured object point, as determined by the displacement measuring device, exceeds a predetermined threshold, the motion control unit, after releasing the end of the substrate by the clamping member, causes the clamping member to hold the end of the substrate again.

2. The screen printing machine according to claim 1, wherein, The one or more measurement points include the target point.

3. The screen printing machine according to claim 1, wherein, The screen printing machine also features: A substrate lifting device that raises a substrate holding device during the printing of the viscous fluid onto the substrate; and The rise amount determination unit determines the rise amount of the substrate holding device. The rise determination unit determines the rise based on the displacement of the one or more measurement target points measured by the displacement measuring device.

4. The screen printing machine according to claim 1, wherein, The screen printing machine also includes an ejection volume determination unit that determines the ejection volume of air ejected from the air nozzle. The target points include a first target point and a second target point that is different from the first target point. The ejection volume determination unit determines the ejection volume of the air for the second target point as a second ejection volume, which is different from the first ejection volume of the air for the first target point. The displacement measuring device measures the vertical displacement of the first measuring object point corresponding to the first target point, and measures the vertical displacement of the second measuring object point corresponding to the second target point.

5. The screen printing machine according to claim 1, wherein, The screen printing machine also includes an opening area determining unit that determines the opening area of ​​the air nozzle outlet. The target points include a first target point and a second target point that is different from the first target point. The opening area determination unit determines the opening area of ​​the nozzle for the second target point as a second opening area, which is different from the first opening area of ​​the nozzle for the first target point. The displacement measuring device measures the vertical displacement of the first measuring object point corresponding to the first target point, and measures the vertical displacement of the second measuring object point corresponding to the second target point.

6. The screen printing machine according to claim 1, wherein, The screen printing machine also features: A scraper is used to fill the through-hole of the mask with the viscous fluid; and The scraper action determination unit determines the force that presses the scraper against the upper surface of the mask and the speed at which the scraper moves along the upper surface of the mask. The scraper action determination unit determines at least one of the force and the speed based on the displacement of the measurement object point measured by the displacement measuring device.

Images