JP7012169B2 - Screen printing machine - Google Patents

Description

The technique disclosed herein relates to a screen printing machine that prints a viscous fluid onto a substrate using a mask on which a printing pattern consisting of through holes is formed.

Patent Document 1 discloses a solder printing machine. This solder printing machine includes a mask placed on a circuit board and a squeegee that imprints cream solder (an example of a viscous fluid) on the mask. The cream solder is printed on the printed matter by moving the squeegee along the surface of the mask supplied with the cream solder. Such a printing method using a mask and a squeegee is generally called screen printing.

In screen printing, if the viscosity of the viscous fluid is not appropriate, printing defects are likely to occur. Further, the appropriate printing conditions differ depending on the viscosity of the viscous fluid to be printed. However, the viscosity of a viscous fluid changes over time and also with temperature. Therefore, in the solder printing machine of Patent Document 1, whether or not the viscosity of the cream solder on the mask is normal is determined based on the torque of the motor required for the squeegee to move the cream solder on the mask.

JP-A-2015-039877

In the technique of Patent Document 1, the viscosity of the viscous fluid is determined based on the torque of the motor that moves the squeegee. The torque of the motor when moving the squeegee is not determined only by the viscosity of the viscous fluid, but is also affected by other changing factors such as the coefficient of friction between the squeegee and the mask. Further, the influence on the motor torque is larger in other factors than in the viscosity of the viscous fluid. Therefore, the present specification provides a screen printing machine capable of measuring the viscosity of a viscous fluid without using the torque of a motor for moving a squeegee.

The screen printing machine disclosed in the present specification prints a viscous fluid on a substrate by using a mask on which a printing pattern consisting of through holes is formed.
This screen printing machine includes a contact member. Further, in this screen printing machine, the contact member can be moved by a drive device to a contact position where the tip of the contact member comes into contact with the viscous fluid and a separation position where the tip of the contact member separates from the viscous fluid.
Further, this screen printing machine is provided with a measuring device for measuring the length of the viscous fluid hanging from the tip of the contact member when the contact member is moved from the contact position to the separated position by the drive device.
Further, this screen printing machine sets the printing conditions for printing the viscous fluid on the substrate based on the measurement result of the measuring device by the control device.

Due to the viscosity of the viscous fluid, when the contact member is moved to the contact position, the viscous fluid adheres to the tip of the contact member. Then, when the contact member is moved from the contact position to the separated position, the viscous fluid hangs down from the tip of the contact member due to gravity. The length of the viscous fluid hanging from the tip of the contact member (hereinafter referred to as the hanging length) changes depending on the viscosity of the viscous fluid. Specifically, when the viscosity is high, the hanging length becomes short. When the viscosity is low, the sagging length becomes long. Therefore, by measuring the sagging length of the viscous fluid, the viscosity of the viscous fluid can be measured without using the torque of the motor for moving the squeegee.
Further, by setting the printing conditions using the measurement result, it is possible to set the printing conditions suitable for the changing viscosity of the viscous fluid.

Further, the mask of the screen printing machine disclosed in the present specification has a surface to which a viscous fluid is supplied, and the contact member may be a squeegee that fills the through holes of the mask with the viscous fluid.
Further, this screen printing machine utilizes a drive device to press the squeegee against the surface of the mask at a predetermined angle and at a predetermined pressure while pressing the squeegee against the surface of the mask in a horizontal direction to the surface of the mask. It can be moved at a predetermined speed, and may be moved at a predetermined speed in a direction orthogonal to the surface of the mask.
In that case, the contact position is the position where the tip of the squeegee contacts the viscous fluid supplied to the surface of the mask, and the separation position is the viscous fluid supplied to the surface of the mask and the viscous fluid hanging from the tip of the squeegee. It may be a separated position.

The screen printer prints the viscous fluid on the printed matter by moving the squeegee along the surface of the mask supplied with the viscous fluid. When the squeegee is brought into contact with the viscous fluid at the contact position and moved to the separated position, the viscous fluid hangs down.
According to this screen printing machine, the viscosity of a viscous fluid is measured by measuring the length of the viscous fluid hanging from the squeegee. Since the squeegee used for printing is used, it is not necessary to separately provide a contact member only for measuring the viscosity of the viscous fluid.

The screen printers disclosed herein use a measuring device to move from the squeegee to the mask as the squeegee moves in a direction orthogonal to the surface of the mask after the squeegee fills the through holes of the mask with viscous fluid. The length of the elongating viscous fluid may be measured.

The screen printer moves the squeegee in one direction to move the viscous fluid, and then moves the squeegee in a direction orthogonal to the surface of the mask in order to move the viscous fluid in the opposite direction. When the squeegee moves in a direction orthogonal to the surface of the mask, the viscous fluid adheres to the squeegee and moves together, and hangs down due to gravity. The viscosity of the viscous fluid can be measured by measuring the hanging length.

Further, the measuring device in the screen printing machine disclosed in the present specification is a first viscous fluid that hangs down from the tip of the contact member when the contact member is moved from the contact position to the distance position at the first speed by the drive device. The second viscous fluid that hangs down from the tip of the contact member when the contact member is moved from the contact position to the distance position by a driving device at a second speed different from the first speed. You may measure the length of.
Further, the control device may set printing conditions for printing the viscous fluid on the substrate based on the first length and the second length measured by the measuring device.

According to this screen printing machine, it is possible to suppress the measurement variation of the viscosity of the viscous fluid by measuring the hanging length by changing the speed at which the contact member is moved.

The screen printing machine disclosed in the present specification may output a signal indicating the occurrence of an abnormality by the output device based on the measurement result of the measuring device.

According to this screen printing machine, when the measured viscosity of the viscous fluid shows an abnormal value, it is possible to notify the operator or the like of the occurrence of the abnormality.

Details and further improvements to the techniques disclosed herein will be described in the "Modes for Carrying Out the Invention" section below.

It is a side view in the case which shows the structure of the printing machine of 1st Embodiment. It is a block diagram which shows the structure of the control of the printing machine of 1st Embodiment. It is an enlarged view which shows the part III of FIG. It is an enlarged view which shows the state which the solder hangs down. It is a partial cross-sectional view in the VV line of FIG. It is a side view which shows the movement of the squeegee of 2nd Example.

The screen printing machine 1 (hereinafter referred to as a printing machine 1) of the first embodiment will be described with reference to the drawings. The printing machine 1 is a device that prints cream solder, which is a viscous fluid, on a circuit board, which is a printed matter, and conveys it to an electronic component mounting device, which is a subsequent process. The direction on the negative side of the Y axis in the drawing is expressed as the front side. Further, the direction on the positive side of the Y axis is expressed as the rear side, the direction on the positive side of the Z axis is expressed as the upper side, and the direction on the negative side of the Z axis is expressed as the lower side.

The configuration of the printing machine 1 will be described with reference to FIG. FIG. 1 is a side view of the inside of the case 2 of the printing machine 1. The printing machine 1 has a squeegee unit 20, a squeegee drive device 4, a board transfer device 16, a board holding device 14, a solder supply device 40, a measuring device 50, a controller 90, and the like in a case 2 which is a box-shaped housing. is doing. Further, a monitor 92 is provided on the front side of the case 2. Although the case 2 is drawn through in FIG. 1, it is made of six plate materials in practice, and the inside of the printing machine 1 is partitioned.

As shown in FIG. 1, a support base 12 is provided on the front side at a height substantially in the middle of the case 2 of the printing machine 1. Similarly, a support base 12 is also provided on the rear side. The support base 12 on the front side and the support base 12 on the rear side are provided at the same height. The mask 80 is arranged so as to be bridged over two support bases 12. In the mask 80, the front end and the rear end are fixed from the upper side by the mask support frame 18. The mask 80 is a plate-shaped member and has one or a plurality of pattern holes 80h corresponding to a print pattern. The pattern hole 80h penetrates the mask 80 in the Z-axis direction. The substrate 70 is arranged on the upper surface of the substrate holding device 14 so as to abut on the lower surface of the mask 80. The printing machine 1 prints the solder on the substrate 70 through the pattern holes 80h.

Further, a board transfer device 16 is provided under the board holding device 14. The board holding device 14 opens the board 70 after printing is completed. The substrate transfer device 16 conveys the printed circuit board 70 in the direction of the positive side of the X-axis (the front side of the paper surface in FIG. 1).

Next, the squeegee unit 20 included in the printing machine 1 will be described. The squeegee unit 20 includes a front squeegee 24 provided on the front side of the unit main body 22 which is a housing, and a squeegee 26 provided on the rear side of the unit main body 22. The front squeegee 24 and the rear squeegee 26 penetrate from the upper surface to the lower surface of the unit main body 22. The front squeegee 24 includes a front angle adjusting device 28 that adjusts the angle of the tip of the front squeegee 24, and a front elevating device 32 that moves the front squeegee 24 in a direction orthogonal to the surface of the mask 80. Similarly, the rear squeegee 26 includes a rear side angle adjusting device 30 that adjusts the angle of the tip of the rear squeegee 26, and a rear elevating device 34 that moves the rear squeegee 26 in a direction orthogonal to the surface of the mask 80. I have.

The squeegee unit 20 is moved in the front-rear direction (Y-axis direction) of the printing machine 1 by the squeegee drive device 4. The squeegee drive device 4 includes a guide rail 10 extending in the front-rear direction of the printing machine 1, a feed screw 8 extending in parallel with the guide rail 10, and a servomotor 6. The guide rail 10 extends in a horizontal direction with respect to the surface of the mask 80 and slidably supports the squeegee unit 20. The servo motor 6 is a motor for moving the squeegee unit 20, and is connected to the squeegee unit 20 via a feed screw 8. That is, the servomotor 6 moves the squeegee unit 20 along the guide rail 10 by rotating the feed screw 8. The servo motor 6 may be another type of motor capable of feedback control, such as a stepping motor.

As described above, the squeegee unit 20 moves each squeegee in a direction orthogonal to the surface of the mask 80 by the front elevating device 32 and the rear elevating device 34. For example, when the squeegee unit 20 is moved from the front side (Y-axis negative side) to the rear side (Y-axis positive side) to print solder on the substrate 70, the squeegee unit 20 first masks the tip of the front side squeegee 24. Press against the surface of. Then, the unused rear squeegee 26 is separated from the mask 80. At that time, the solder is supplied to the rear side of the front squeegee 24 on the surface of the mask 80 and to the front side of the pattern hole 80h. Then, the squeegee unit 20 moves backward while pressing the tip of the front squeegee 24 against the surface of the mask 80 by the squeegee drive device 4. Since the tip of the front squeegee 24 is pressed against the surface of the mask 80, the solder supplied on the surface of the mask 80 is pushed by the front squeegee 24 and moves to the rear side, and is filled in the pattern hole 80h. Ru. The filled solder passes through the penetrating pattern hole 80h and comes into contact with the surface of the substrate 70. As a result, the solder is printed on the substrate 70.

Further, when printing solder on the substrate 70, the squeegee unit 20 can adjust the pressure (hereinafter referred to as printing pressure) pressed against the mask 80 of the front squeegee 24 by the front elevating device 32. Further, the squeegee unit 20 can adjust the angle of the front squeegee 24 with respect to the surface of the mask 80 by the front angle adjusting device 28. Further, the printing machine 1 can adjust the moving speed of the squeegee unit 20 by the squeegee driving device 4, and as a result, can adjust the moving speed of the squeegee 24 or 26 during printing in the printing direction. By appropriately setting the printing conditions including these depending on the type and viscosity of the solder used for printing, it is possible to suppress the occurrence of printing defects such as solder shortage and solder leakage.

The printing machine 1 includes a controller 90 and a monitor 92. In FIG. 1, a controller 90 and a monitor 92 are shown above the side view of the printing press 1 to aid understanding. Actually, the controller 90 and the monitor 92 are provided on the front surface of the printing machine 1 (in FIG. 1, the surface on the left side of the paper surface). The controller 90 controls each device of the printing machine 1. Further, the monitor 92 presents the setting state and working state of the solder printing machine 1 to the worker, and receives various inputs from the worker via a switch or the like. Details of the control configuration of the controller 90 will be described later.

Further, a solder supply device 40 and a measuring device 50 are provided on the front side of the printing machine 1. Further, a tray 46 is arranged on the lower side of the measuring device 50, and the tray 46 is arranged on the upper surface of the support base 12 on the front side. The solder supply device 40 and the measuring device 50 are connected to each other via the measuring driving device 48. Further, the solder supply device 40 and the measurement device 50 are slidably supported in the front-rear direction of the printing machine 1 by the guide rail 10 via the measurement drive device 48. The solder supply device 40 includes a solder container 42 and a solder discharge unit 44. The solder supply device 40 is slidably attached in the X-axis direction as well. The solder supply device 40 supplies the solder 36 in the solder container 42 from the solder discharge portion 44 to the surface of the tray 46 and the surface of the mask 80 while moving in the X-axis direction. Therefore, the solder 36 is supplied in a form extending in the X-axis direction.

The measuring device 50 includes a measuring device main body 52 connected to the measuring driving device 48, a measuring elevating device 54 extending downward from the measuring device main body 52, and a measuring device tip 56. Further, as will be described in detail later, the measuring device 50 has a laser measuring device 60 on the lower side of the measuring device 50 and on the back side of the paper surface. The measuring device 50 measures the viscosity of the solder 36 supplied to the tray 46 by the solder supply device 40 by using the laser measuring device 60. The details of the viscosity measuring method will be described later.

As described above, the controller 90 controls each device of the printing machine 1. FIG. 2 shows a configuration of control performed by the controller 90 of the printing machine 1. The controller 90 has a central processing unit (CPU) and is configured by using a microprocessor operated by software. The controller 90 also has a volatile random access memory (RAM), a non-volatile read-only memory (ROM), a hard disk drive (HDD), and an input / output interface. The controller 90 controls each part of the printing machine 1 by using the input / output interface.

The controller 90 issues a command to the board transfer device 16 and the board holding device 14 to control the loading / unloading of the board 70 and the holding of the board 70 on the mask 80. The controller 90 controls the speed at which the squeegee is raised and lowered and the printing pressure by the front raising and lowering device 32 and the rear raising and lowering device 34 of the squeegee unit 20. The controller 90 controls the angle at which the tip of each squeegee is pressed against the surface of the mask 80 by the front angle adjusting device 28 and the rear angle adjusting device 30 of the squeegee unit 20. The controller 90 controls the speed at which the squeegee unit 20 moves and the direction in which the squeegee unit 20 moves by the squeegee drive device 4. The controller 90 sends a command to the solder supply device 40 to supply solder to the surface of the tray 46 and the mask 80. That is, the controller 90 sets the printing conditions of the printing machine 1.

Further, the controller 90 receives the viscosity measurement result of the solder 36 from the measuring device 50. The controller 90 transmits to each device the printing pressure suitable for the received viscosity measurement result, the angle of the tip of the squeegee, the speed at which each squeegee is moved up and down, the speed at which the squeegee being printed moves in the printing direction, and the like. That is, the printing conditions are set using the viscosity measurement result. This makes it possible to set printing conditions suitable for the changing viscosity of the viscous fluid.

Here, the movements performed by the measuring device 50 will be described with reference to FIGS. 3 to 4. 3 to 4 are enlarged views of the range III surrounded by the alternate long and short dash line in FIG. 1. First, the solder supply device 40 supplies the solder 36a to the surface of the tray 46 while moving in the X-axis direction. Therefore, the solder 36a extends in the X-axis direction. After that, the measuring device 50 is moved above the solder 36a by the measuring driving device 48. Here, the measurement tip portion 56 arranged at the tip of the measuring device 50 is also a plate-shaped member extending in the X-axis direction. The measurement tip 56 has the same shape as the tip of the front squeegee 24. Further, the measurement tip portion 56 is made of the same polyurethane as the tip of the front squeegee 24 and the tip of the rear squeegee 26.

After that, the measurement elevating device 54 moves the measurement tip 56 toward the tray 46. As a result, as shown in FIG. 3, the measuring tip 56 and the solder 36a come into contact with each other. When the measuring tip 56 comes into contact with the solder 36a, the solder 36b, which is a part of the solder 36a, adheres to the measuring tip 56.

Next, as shown in FIG. 4, the measurement elevating device 54 moves the measurement tip portion 56 upward. As described above, the solder 36b is attached to the measurement tip portion 56. Therefore, when the measurement tip 56 moves upward, as shown in FIG. 4, the solder 36b adhering to the measurement tip 56 also moves upward. When the solder 36b moves upward, the solder 36a remaining on the tray 46 and the solder 36b adhering to the measurement tip 56 are separated from each other. That is, the measuring tip 56 is separated from the contacted solder 36a. At that time, the solder 36b adhering to the measurement tip 56 hangs down from the measurement tip 56 due to gravity.

A method of measuring the viscosity of the solder 36 will be described with reference to FIG. FIG. 5 is a partial cross-sectional view of the measuring device 50 and the solders 36a and 36b in VV of FIG. As described above, the solder 36a extends in the X-axis direction. The amount and viscosity of the solder 36a in the X-axis direction are not constant. Therefore, the amount and viscosity of the solder 36b adhering to the measurement tip 56 are not constant in the X-axis direction. That is, the hanging length of the solder 36b is not constant in the X-axis direction. The laser measuring instrument 60 measures the distance between the lower end of the measurement tip 56 and the lowermost point of the solder 36b as the hanging length. If the position (height) of the lower end of the measurement tip 56 is known in advance from the position where the measurement elevating device 54 is stopped, the hanging length is measured by measuring the position of the lower end of the solder 36b. be able to.

The hanging length of the solder 36b correlates with the viscosity of the solder 36b. Specifically, if the hanging length is long, the viscosity of the solder 36b is low. On the contrary, if the hanging length is short, the viscosity of the solder 36b is high. Therefore, the measuring device 50 can measure the viscosity of the solder 36b by measuring the hanging length. That is, the printing machine 1 can measure the viscosity of the solder 36b without using the torque of the motor that moves the squeegee.

The laser measuring instrument 60 transmits the measured sagging length to the controller 90. As described above, the controller 90 sets the printing conditions suitable for the viscosity of the solder 36b from the received hanging length. The controller 90 transmits the set print conditions to each device. That is, the printing machine 1 can set printing conditions suitable for the viscosity of the solder 36b by using the measurement result.

Subsequently, the viscosity measuring method in the printing press 1a of the second embodiment will be described with reference to FIG. FIG. 6 is an enlarged view of a side view showing the movement of the squeegee unit 20 during printing. In FIG. 6, in order to make the figure easier to understand, the case 2, the support base 12, the substrate transfer device 16 and the like in FIG. 1 are not shown. In the printing machine 1a of the second embodiment, the solder supply device supplies the solder 36d to the surface of the mask 80. As described above, the front elevating device 32 moves the front squeegee 24 toward the surface of the mask 80. As a result, the tip of the front squeegee 24 comes into contact with the solder 36d. When the tip of the front squeegee 24 comes into contact with the solder 36d, a part of the solder 36d adheres to the tip of the front squeegee 24. After that, the front elevating device 32 moves the front squeegee 24 in the direction of the arrow US1 at a speed of, for example, 50 mm / s. Here, as shown in FIG. 6, the direction of the arrow US1 is orthogonal to the surface of the mask 80. As described above, a part of the solder 36d is attached to the tip of the front squeegee 24. Therefore, when the front squeegee 24 moves in the direction of the arrow US1, the solder 36d adhering to the tip of the front squeegee 24 also moves as shown in FIG. At that time, the adhered solder 36d hangs down from the tip of the front squeegee 24 due to gravity. Although not shown in FIG. 6, a laser measuring instrument is also provided on the back side of the front side squeegee 24 of the squeegee unit 20 of the printing machine 1a. As shown in FIG. 5, also in the printing press 1a of the second embodiment, the viscosity of the solder 36d is measured by measuring the hanging length of the solder 36d adhering from the tip of the front squeegee 24 using a laser measuring instrument. Can be measured. That is, the printing machine 1a can measure the viscosity of the solder 36d without using the torque of the motor that moves the squeegee.

Similar to the first embodiment, the laser measuring instrument transmits the measured sagging length to the controller 90. As described above, the controller 90 sets the printing conditions suitable for the viscosity of the solder 36d from the received hanging length. The controller 90 transmits the set print conditions to each device. That is, the printing machine 1a can set the printing conditions suitable for the viscosity of the solder 36d by using the measurement result. In the printing machine 1a of the second embodiment, the drive device described in the claims is provided by the squeegee drive device 4 for moving the squeegee unit 20 in the printing direction and the elevating devices 32 and 34 for raising and lowering the squeegees 24 and 26. An example is configured.

Further, the front squeegee 24 of the printing machine 1a of the second embodiment is pressed against the surface of the mask 80 at a predetermined angle and with a predetermined pressure by the squeegee drive device 4, while being pressed against the surface of the mask 80. It moves at a predetermined speed in the direction RS1 horizontal to the surface of 80. In other words, the front squeegee 24 moves in the direction of arrow RS1 in FIG. 6 while filling the pattern hole 80h of the mask 80 with the solder 36. That is, the printing machine 1a prints the solder 36 on the substrate 70 using the front squeegee 24.

Therefore, by using the printing machine 1a of the second embodiment, the viscosity of the solder can be measured by using the squeegee required for printing. That is, since the squeegee used for printing is used, it is not necessary to separately provide a contact member only for measuring the viscosity of the solder.

Further, the printing machine 1a can further measure the viscosity of the solder 36e at the position of the squeegee unit 20a shown in FIG. The squeegee unit 20a shows the state of the squeegee unit 20 after the front squeegee 24 fills the pattern holes 80h of the mask 80 with the solder 36. Although the amount of the solder 36d before printing is reduced by filling the pattern holes 80h of the mask 80, the remaining solder 36e is in contact with the front squeegee 24. Therefore, a part of the solder 36e adheres to the tip of the front squeegee 24. After that, the front elevating device 32 moves the front squeegee 24 in the direction of the arrow US2. The direction of the arrow US2 is orthogonal to the surface of the mask 80. A part of the solder 36e is attached to the tip of the front squeegee 24. Therefore, when the front squeegee 24 moves in the direction of the arrow US2, the solder 36e attached to the tip of the front squeegee 24 also moves together with the solder 36b shown in FIG. At that time, the adhered solder 36e hangs down from the tip of the front squeegee 24 due to gravity. Although not shown in FIG. 6, a laser measuring instrument is also provided on the back side of the front side squeegee 24 of the squeegee unit 20a of the printing machine 1a. Similar to the solder 36b shown in FIG. 5, in the printing machine 1a of the second embodiment, the solder 36e adhered by the laser measuring instrument by measuring the hanging length of the solder 36e from the tip of the front squeegee 24. Viscosity can be measured. That is, the printing machine 1a can measure the viscosity of the solder 36e without using the torque of the motor that moves the squeegee. In the meantime, the substrate transfer device 16 transfers the substrate 70 to a subsequent process, and arranges a new substrate on the upper surface of the substrate holding device 14.

After that, the squeegee unit 20a moves the rear squeegee 26 in the direction of the arrow US3 using the rear elevating device 34 while the front squeegee 24 is moving in the direction of the arrow US2. The squeegee unit 20a presses the tip of the rear squeegee 26 against the surface of the mask 80 at a predetermined angle and a predetermined pressure against the surface of the mask 80, and determines the direction RS2 horizontal to the surface of the mask 80. Move at the speed of. That is, the squeegee unit 20a prints the solder 36 on the new substrate 70. After that, the rear squeegee 26 moves away from the mask 80 this time. At this time, the viscosity of the solder 36 remaining on the surface of the mask 80 is measured. When the viscosity of the solder 36 is measured, the front squeegee 24 moves toward the surface of the mask 80. In the meantime, the substrate transfer device 16 transfers the substrate 70 to a subsequent process, and arranges a new substrate on the upper surface of the substrate holding device 14. Hereinafter, the measurement of the viscosity of the solder and the printing of the solder on the substrate are repeated alternately.

As described above, in the printing machine 1a, in order to change the moving direction of the squeegee unit 20, the front and rear squeegees are exchanged by moving them up and down for each printing. That is, by measuring the hanging length from the tip of the squeegee at the time of raising and lowering, the viscosity of the solder during printing of the printing machine 1a can be measured without using the torque of the motor for moving the squeegee. The viscosity of solder usually tends to increase over time. In other words, the viscosity of the solder changes during printing. That is, by measuring the viscosity of the solder by utilizing the operation of exchanging the front and rear squeegees, it is possible to measure the viscosity of the solder that changes during printing. The controller 90 controls each device using this measurement result. Therefore, the controller 90 can set printing conditions suitable for the viscosity of the solder that changes during printing. The viscosity can be measured every time the front and rear squeegees are replaced, but the measurement frequency can be changed. For example, the viscosity may be measured every two times when the squeegee is replaced in accordance with the transportation of the substrate 70.

Further, in the above-described embodiment, when measuring the hanging length of the solder 36, the speed at which the measurement tip portion 56 and the squeegee are moved can be changed. Specifically, for example, when the solder 36 is attached to the measurement tip portion 56 of the printing machine 1 of the first embodiment shown in FIGS. 3 to 4, and the speed at which the measurement tip portion 56 is moved upward is set to 100 mm / s. The hanging length is measured, and then the speed at which the measuring tip 56 is moved upward is changed to 50 mm / s, and the hanging length is measured. If the speed at which the measurement tip 56 is moved upward changes, the hanging length also changes. Further, the deformation of the viscous fluid depends on the velocity, and even if the same load is applied, the deformation amount is small if the velocity is high, and the deformation amount is large if the velocity is slow. By measuring the sagging length at different speeds, it is possible to suppress variations in the measurement of solder viscosity.

The measuring device 50 transmits the hanging length measured at different speeds to the controller 90. The controller 90 estimates the viscosity from the different sagging lengths received and sets printing conditions suitable for the estimated viscosity. For example, a first sagging length when the squeegee is moved at a first speed (eg, 100 mm / s) and a second sagging length when the squeegee is moved at a second speed (eg, 50 mm / s). The viscosity of the solder may be estimated using the difference from the solder. Alternatively, a control map for determining the printing conditions with the first hanging length and the second hanging length as parameters may be created in advance, and the printing conditions may be set using the measured values and the control map. The measurement of the sagging length at different speeds is not limited to two speeds, and printing conditions may be set using the sagging lengths measured at three or more different speeds.

Further, the controller 90 can send a command to the warning device 62 and output a signal indicating the occurrence of an abnormality to the monitor 92 when the viscosity of the solder 36 transmitted from the measuring device 50 exceeds a predetermined threshold value. As a result, when the viscosity of the viscous fluid measured by the measuring device 50 shows an abnormal value, it is possible to notify the operator or the like of the occurrence of the abnormality. The threshold value differs depending on the type of solder used for printing, the surrounding environmental conditions, and the like.

The mask 80 of the printing machine 1 of this embodiment is a metal mask made of a metal material. However, in the technique disclosed in the present specification, the specific material and structure of the mask 80 are not particularly limited. Further, as described above, the measurement tip 56 and the tip of each squeegee are made of polyurethane, but the technique disclosed in the present specification also applies to a metal squeegee using another material, for example, stainless steel. , Can be applied.

Further, the squeegee unit 20 of the printing machine 1 of the present embodiment includes two squeegees 24 and 26 depending on the moving direction, but as another embodiment, the squeegee unit 20 is a single or three or more squeegees. May be provided. Further, in the printing machine 1 of this embodiment, solder is supplied to the surface of the tray 46 and the mask 80 by the solder supply device 40. The solder supply device 40 is not an essential component, and the operator may manually supply the solder to the surface of the tray 46 or the mask 80.

In the printing presses 1 and 1a of this embodiment, the solder sagging length is measured by a laser measuring instrument, but the method of measuring the solder sagging length is not limited to the laser measuring instrument and is not limited to other measuring instruments. May be used.

Although specific examples of the present invention have been described in detail above, these are merely examples and do not limit the scope of claims. The techniques described in the claims include various modifications and modifications of the specific examples exemplified above. The technical elements described herein or in the drawings exhibit their technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the techniques exemplified in the present specification or the drawings can achieve a plurality of purposes at the same time, and achieving one of the purposes itself has technical usefulness.

1, 1a: Printing machine 2: Case 4: Squeegee drive device 6: Servo motor 8: Feed screw 10: Guide rail 12: Support base 14: Board holding device 16: Board transfer device 18: Mask support frame 20, 20a: Squeegee Unit 22: Unit main body 24: Front squeegee 26: Rear squeegee 28: Front angle adjusting device 30: Rear angle adjusting device 32: Front elevating device 34: Rear elevating device 36, 36a to e: Solder 40: Solder supply device 42: Solder container 44: Solder discharge unit 46: Tray 48: Measurement drive device 50: Measuring device 52: Measuring device main body 54: Measurement elevating device 56: Measurement tip 60: Laser measuring instrument 62: Warning device 70: Board 80 : Mask 80h: Pattern hole 90: Controller 92: Monitor

Claims (4)

In a screen printing machine that prints a viscous fluid on a substrate using a mask on which a printing pattern consisting of through holes is formed.
With the contact member,
A drive device capable of moving the contact member to a contact position where the tip of the contact member contacts the viscous fluid and a separation position where the tip of the contact member separates from the viscous fluid.
A measuring device that measures the length of the viscous fluid that hangs down from the tip of the contact member when the contact member is moved from the contact position to the separated position by the drive device.
A control device for setting printing conditions when printing the viscous fluid on the substrate based on the measurement result of the measuring device is provided .
The measuring device is
When the contact member is moved from the contact position to the separation position at the first speed by the drive device, the first length of the viscous fluid hanging from the tip of the contact member is measured, and the first length is measured .
The second length of the viscous fluid that hangs down from the tip of the contact member when the contact member is moved from the contact position to the distance position by the drive device at a second speed different from the first speed. Measure and
The control device sets printing conditions for printing the viscous fluid on the substrate based on the first length and the second length measured by the measuring device, screen printing. Machine. The mask has a surface to which the viscous fluid is supplied.
The contact member is a squeegee that fills the through hole of the mask with the viscous fluid.
The drive device moves the squeegee in a direction horizontal to the surface of the mask at a predetermined speed while pressing the squeegee against the surface of the mask at a predetermined angle and at a predetermined pressure. It can be moved at a predetermined speed in a direction orthogonal to the surface of the mask.
The contact position is a position where the tip of the squeegee comes into contact with the viscous fluid supplied to the surface of the mask.
The screen printing machine according to claim 1, wherein the separation position is a position where the viscous fluid supplied to the surface of the mask and the viscous fluid hanging from the tip of the squeegee are separated from each other. The measuring device extends from the squeegee in the direction of the mask when the squeegee fills the through hole of the mask with the viscous fluid and then the squeegee moves in a direction orthogonal to the surface of the mask. The screen printing machine according to claim 2, which measures the length of a viscous fluid. The screen printing machine according to any one of claims 1 to 3 , further comprising an output device that outputs a signal indicating the occurrence of an abnormality based on the measurement result of the measuring device.

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