Pressure device and viscosity measurement method

Abstract

In this printing device, a viscosity measuring unit for measuring the viscosity of a solder paste comprises the following: a suction section encompassing a cylindrical body with an opening that draws in solder paste in contact with the suction opening, and a screw enclosed within the cylindrical body; a motor that rotates the screw or the cylindrical body when the screw is in contact with the solder paste; and a measuring unit that detects a torque acting on the screw or the cylindrical body and, based on the torque, measures the viscosity or a viscosity equivalent value of the solder paste. The measuring unit measures the viscosity or viscosity equivalent value based on the torque detected after the motor has rotated for a predetermined time.

Description

Technical field

[0001] The present disclosure relates to a pressure device and a viscosity measurement method. State of the art

[0002] In related technology, a screen printing device is known that prints solder paste onto a printed circuit board through a through-hole in a mask by moving the solder paste placed on the mask along the mask with a squeegee. The screen printing device from patent literature 1 comprises a viscosity sensing device that determines a viscosity equivalent value corresponding to the viscosity of the solder paste placed on the mask, and a screw cleaning device that cleans a screw serving as a detector for the viscosity sensing device. List of cited documents Patent literature

[0003] Patent Literature 1: JP2008-307864A Summary of the invention: Technical problem

[0004] With the viscosity measuring device described in patent literature 1, it is difficult to obtain a suitable viscosity equivalent value that corresponds to the viscosity of the solder paste, since the amount of solder paste adhering to the screw is not stable. This means that it is difficult to obtain a highly reliable viscosity measurement during the manufacturing of the printed circuit board, and there is room for improvement.

[0005] The present disclosure was made taking into account the above circumstances and provides a pressure device and a viscosity measurement method with which a highly reliable measurement can be obtained during the manufacture of a circuit board. Solution to the problem

[0006] One aspect of the present disclosure is a printing device that prints a solder paste onto a circuit board via a mask with a predetermined opening pattern, the printing device comprising a viscosity measuring unit configured to measure the viscosity of the solder paste, the viscosity measuring unit comprising a suction section comprising a tubular body with an opening and configured to draw in the solder paste in contact with an opening and a screw contained in the tubular body, a motor configured to rotate the screw or tubular body in a state in which the screw is in contact with the solder paste, a measuring unit configured to detect a torque acting on the other screw or tubular body and to measure the viscosity or a viscosity equivalent value of the solder paste based on the torque, and a control unit.which is configured to control the motor, with the measuring unit measuring the viscosity or viscosity equivalent value based on the torque detected after the motor has been rotated by the control unit for a predetermined time.

[0007] One aspect of the present disclosure is a viscosity measurement method for measuring the viscosity of a solder paste printed onto a circuit board via a mask with a predetermined opening pattern using a suction section, wherein the suction section comprises a tubular body with an opening and is configured to draw in the solder paste in contact with a suction opening, and a screw contained in the tubular body, wherein the viscosity measurement method comprises: a rotary step for rotating either the screw or the tubular body by a motor in a state in which the screw is in contact with the solder paste;and a measuring step for detecting a torque acting on the screw or tubular body and for measuring the viscosity or a viscosity equivalent value of the solder paste based on the torque, wherein the measuring step includes a step for measuring the viscosity or viscosity equivalent value based on the torque detected after the motor has rotated in the rotation step for a predetermined time. Advantageous effects of the invention

[0008] According to the present disclosure, a highly reliable measurement can be obtained during the manufacture of a circuit board. Brief description of the drawings Fig. Figure 1 is a side view of a main part showing a configuration example of a printing device according to an embodiment of the present disclosure (Part 1). Fig. Figure 2 is a side view of a main part, showing the configuration example of the printing device (part 2). Fig. Figure 3 is a side view showing a configuration example of a part of a printhead contained in the printing device. Fig. 4A is a diagram showing an example of a state in which the printing device is performing a printing operation (Part 1). Fig. 4B is a diagram showing an example of the state in which the printing device performs the printing process (Part 2). Fig. Figure 5 is a side view showing a state in which the viscosity or similar of a solder paste is measured by a viscometer provided in the printing device. Fig. Figure 6 is a diagram showing the measurement of the viscosity or similar properties of the solder paste using the viscometer. Fig. Figure 7 is a diagram showing an example of a position in which the viscometer is positioned relative to the solder paste. Fig. Figure 8A is a block diagram showing a configuration example of a control system in the printing device. Fig. 8B is a diagram showing an example of a table that stores information about a reference time T1. Fig. 8C is a diagram showing an example of a table that stores information about a cleaning notification time T2. Fig. Figure 9 is a flowchart showing an operating example of the printing device. Fig. Figure 10 is a flowchart showing an example of a viscosity measurement process. Fig. Figure 11 is a flowchart showing an operational example related to managing the state of the viscometer. Fig. Figure 12 is a flowchart showing an example of a solder paste replacement process. Description of exemplary implementations

[0009] An embodiment of the present disclosure is described in detail below with reference to the drawings, where appropriate. However, unnecessarily detailed descriptions may be omitted. For example, detailed descriptions of already known facts and redundant descriptions of essentially identical configurations may be omitted. This serves to avoid unnecessary redundancies in the following description and to facilitate understanding by those skilled in the art. The accompanying drawings and the following description are intended to provide those skilled in the art with a sufficient understanding of the present disclosure and are not meant to limit the subject matter described in the claims.

[0010] For example, in the embodiment, "unit" or "device" is not limited to a physical configuration that is mechanically implemented by hardware, but also includes those that implement functions of the configuration by software, such as a program. Functions of a configuration can be implemented by two or more physical configurations, or functions of two or more configurations can, for example, be implemented by one physical configuration. (Example of implementation)

[0011] The Fig. 1 and Fig. Figure 2 shows side views of a main part, illustrating a configuration example of a printing device 1 according to an embodiment of the present disclosure.

[0012] In the present embodiment, a transport direction of a circuit board (a depth direction of a sheet of Fig. 1) defined as the X-direction, a direction orthogonal to the X-direction in a horizontal plane (a left-right direction in Fig. 1) is defined as the Y-direction, and a direction orthogonal to the horizontal plane (a top-bottom direction in Fig. 1) is defined as the Z-direction.

[0013] The printing device 1 is a device that prints a solder paste Pst onto a circuit board KB and sends the circuit board KB to a component assembly device on a downstream side. The printing device 1 comprises a mask 11, a circuit board support section 12, a print head 13, a head movement mechanism 14, a viscometer 15, a viscometer movement unit 16, and a control device 17.

[0014] In Fig. 1. The mask 11 consists of a thin sheet metal part extending in a horizontal plane, or a layered part, such as fabric or resin. As in the Fig. 2 and Fig. As shown in Figure 7, the mask 11 has predetermined opening patterns 11K corresponding to the arrangement of a plurality of electrodes DK provided on the circuit board KB. The opening pattern 11K is formed in a pattern area in the center of the mask 11. The circuit board support section 12 holds the circuit board KB and positions it relative to the mask 11. The circuit board support section 12 comprises a circuit board support table 12a, which supports the circuit board KB placed thereon, and side clamps 12b, which clamp the side faces of the circuit board KB in the Y direction to fix its position. The side clamp 12b comprises a pair of block-shaped elements arranged in the horizontal direction (Y direction). The pair of side clamps 12b encloses and holds the circuit board KB, which is transported from one side (Y direction) in a direction orthogonal to the Y direction (X direction).The circuit board support table 12a holds an upper surface of the circuit board KB at the same height as the upper surfaces of the pair of side terminals 12b (. Fig. 2).

[0015] The circuit board support section 12, which holds the KB board, is moved upwards, while its position in the horizontal direction is adjusted by a movement mechanism (not shown) ( Fig. 2 → Fig. 1) This positions the circuit board KB in relation to the mask 11 and brings it into contact with or near the underside of the mask 11, and each electrode DK is positioned so that it overlaps the corresponding opening pattern 11K in a horizontal direction ( Fig. 1) This enables a “printing process” to be described later. Such a process for enabling the “printing process” of the circuit board support section 12 is referred to as a “print preparation process”.

[0016] In Fig. The printhead 13 comprises two lifting and lowering cylinders 22 and two doctor blade units 23 on a base section 21. The base section 21 is a horizontally extending element and is movable in the Y-direction in a space above the mask 11. The two lifting and lowering cylinders 22 are positioned opposite each other in the Y-direction within the base section 21, and each of the piston rods 22R projects below the base section 21.

[0017] The two doctor blade units 23 are attached to the respective piston rods 22R of the two lifting and lowering cylinders 22. By individually actuating the two lifting and lowering cylinders 22, the two doctor blade units 23 can therefore be raised and lowered relative to the base section 21.

[0018] Fig. Figure 3 is a side view showing a configuration example of a part of the printhead 13 contained in the printing device 1.

[0019] In Fig. Each doctor blade unit 23 comprises a doctor blade holder 31, a doctor blade 32, and an angle-of-attack adjustment unit 33. The doctor blade holder 31 comprises a fixed section 41 and a movable section 42. The fixed section 41 is attached to a lower end of the piston rod 22R. An upper end section of the movable section 42 is connected to the fixed section 41, and the movable section 42 is pivotable about a pivot axis 42J parallel to the X-axis.

[0020] The doctor blade 32 consists of a flat (spatula-shaped) element. An upper edge of the doctor blade 32 is held by the doctor blade holder 31, and the doctor blade 32 extends diagonally below the doctor blade 32. The two doctor blade units 23 are arranged such that the doctor blades 32 are opposite each other in the Y-direction and the distance between them increases towards the lower edge ( Fig. 1) The angle of elevation of each squeegee 32 to the horizontal plane is called the angle of attack θ.

[0021] The angle-of-attack change unit 33 is an actuator that pivots the movable section 42 about the joint axis 42J. Each doctor blade unit 23 can change the angle of attack θ of the doctor blade 32 by actuating the angle-of-attack change unit 33. Fig. Figure 3 shows the squeegee 32 represented by a dashed line (reference symbol 32a) in a case in which the angle of attack θ is increased compared to the squeegee 32 represented by a solid line, and the squeegee 32 represented by a dotted catenary line (reference symbol 32b) shows a case in which the angle of attack θ is decreased compared to the squeegee 32 represented by a solid line.

[0022] The head movement mechanism 14, for example, includes a table mechanism and moves the printhead 13 in the Y direction. When the head movement mechanism 14 moves the printhead 13 in the Y direction, the doctor blade unit 23 also moves in the Y direction.

[0023] The Fig. 4A and Fig. 4B are diagrams that show an example of a state in which the printing device is performing a printing operation. In the Fig. 4A and Fig. In 4B, the representation of the circuit board support section 12 is partially omitted.

[0024] When the solder paste Pst is printed by the printhead 13 onto the electrode DK of the circuit board KB, the circuit board KB is first brought into contact with, or close to, the underside of the mask 11 by the "print preparation process" described above. Then, one of the two squeegees 32 is lowered by the lifting and lowering cylinder 22, and a lower edge of the lowered squeegee 32 is brought into contact with an upper surface of the mask 11. The printhead 13 is then moved horizontally by the head movement mechanism 14. At this point, the printhead 13 is moved in such a way that the squeegee 32 on the side in contact with the mask 11 faces the squeegee 32 on the other side.

[0025] When the printhead 13 moves in a horizontal direction, the squeegee 32, whose lower end is in contact with the mask 11, slides on the mask 11. Accordingly, the solder paste Pst on the mask 11 is scraped off by the squeegee 32 ( Fig. 4A → Fig. 4B) and pressed (filled) into the opening pattern 11K, thereby printing the solder paste Pst onto the electrode DK of the board KB ( Fig. 4B). In the following, the process of the printhead 13 to print the solder paste Pst onto the electrode DK of the circuit board KB through the opening pattern 11K of the mask 11 is referred to as the “printing process”.

[0026] During the printing process by the printhead 13, the solder paste Pst is moved by the squeegee 32 from a position corresponding to one side clamp 12b to a position corresponding to the other side clamp 12b. Therefore, the solder paste Pst is printed onto the multitude of electrodes DK of the circuit board KB. When the printing process is complete, the movement mechanism (not shown) lowers the circuit board support section 12 to perform a "board separation operation", in which the circuit board KB is separated from the mask 11. Fig. 1 → Fig. 2).

[0027] In the printing process described above, the printing device 1 can adjust the state (print state) of the solder paste Pst printed onto the electrode DK of the circuit board KB by changing a printing condition. Here, the "print state" refers to the thickness, shape, and other properties of the solder paste Pst printed onto the electrode DK, and the "printing conditions" include the angle of attack θ, the speed of movement of the print head 13 (i.e., the squeegee 32), the contact force of the squeegee 32 against the mask 11, and the like.

[0028] Fig. Figure 5 is a side view showing a state in which a viscosity of the solder paste Pst or a viscosity equivalent value (hereinafter referred to as viscosity or the like) is measured by the viscometer 15 contained in the printing device 1. The viscosity equivalent value is a value corresponding to the viscosity and is, for example, a measurement corresponding to the viscosity measured under conditions that differ at least partially from the measurement conditions defined as the measurement conditions at the time of the viscosity measurement according to the JIS standard. Fig. In section 5, the illustration of the circuit board support section 12 is partially omitted.

[0029] In the Fig. 1 and Fig. The viscometer 15 is a measuring instrument that measures the viscosity of the solder paste Pst supplied to the mask 11. The viscometer 15 is attached to the base section 21 of the printhead 13 via the viscometer motion unit 16. The detailed configuration of the viscometer 15 is described later.

[0030] In the Fig. 1 and Fig. The viscometer motion unit 16 comprises a base-section-side element 16a attached to the base section 21 of the printhead 13, a viscometer holding element 16b that holds the viscometer 15, and an X-direction motion mechanism 16c that moves the base-section-side element 16a in the X direction along the base section 21. The viscometer holding element 16b is freely raised and lowered relative to the base-section-side element 16a and is raised and lowered relative to the base-section-side element 16a by an actuator (not shown) to allow the viscometer 15 to protrude below the printhead 13. Furthermore, the X-direction movement mechanism 16c can move a section arranged on the base-section-side element 16a, i.e. the viscometer 15, in the X direction.

[0031] Fig. Figure 6 is a diagram showing the measurement of the viscosity or similar properties of the solder paste Pst, using the viscometer 15.

[0032] The viscometer 15 comprises a screw 151, a tubular body 152, and a torque sensor 153. The screw 151 can come into contact with the solder paste Pst and extends along the Z-direction. For example, the screw 151 does not rotate about the Z-direction.

[0033] The tubular body 152 covers the screw 151 from outside an XY plane. That is, the screw 151 is enclosed by the tubular body 152. The tubular body 152 has, for example, a cylindrical (columnar) shape. The tubular body 152 rotates about the Z-direction. The tubular body 152 has an insertion section 154 in which a lower part of the tubular body 152 is open. The insertion section 154 can be located, for example, below a lower end section of the tubular body 152 in the Z-direction or at a lateral end section of the tubular body 152. The insertion section 154 comes into contact with the solder paste Pst on the mask 11 to introduce the solder paste Pst. The insertion section 154 has a suction opening for drawing in the solder paste.The tubular body 152 has an ejection section 155 in which part of the upper surface of the tubular body 152 is open. The ejection section 155 can be located, for example, above an upper end section of the tubular body 152 in the Z-direction or a lateral end section of the tubular body 152. The ejection section 155 ejects the solder paste Pst adhering to the screw 151.

[0034] The torque sensor 153 detects a torque of the screw 151. For example, the torque sensor 153 detects as torque a force exerted on the screw 151 by the solder paste Pst introduced into the tubular body 152.

[0035] Although not shown, the viscometer 15 includes a motor 15M (see Fig. 8A), which rotates the screw 151 and the tubular body 152 relative to each other. For example, the tubular body 152 is rotated about the Z-axis (with the extension direction of the screw 151 as the axis) with respect to the screw 151, which is stationary. The motor 15M can be located outside the viscometer 15 in the printing device 1.

[0036] When the viscosity or similar properties of the solder paste Pst are measured with the viscometer 15, the control device 17 moves the print head 13 with the head movement mechanism 14 and positions the viscometer 15 above the solder paste Pst. The control device 17 then actuates the viscometer movement unit 16 to cause the viscometer 15 to protrude downwards and bring part of the tubular body 152 into contact with the solder paste Pst (state A in the Fig. 5 and Fig. 6) When a portion of the tubular body 152 is brought into contact with the solder paste Pst, the control device 17 causes the motor 15M to rotate the tubular body 152. The solder paste Pst on the mask 11 is drawn (suctioned) from the insertion section 154 of the tubular body 152 into the tubular body 152 in accordance with the rotation of the tubular body 152 and moves sequentially upwards along the screw 151 (in the positive direction in the Z-direction) (state B in Fig. 6) When the upwardly advanced solder paste Pst reaches the ejection section 155 of the tubular body 152, the solder paste Pst is ejected from the ejection section 155 outside the tubular body 152 (state C in Fig. 6).

[0037] It is possible that the solder paste Pst remains in the tubular body 152 at the time of the previous measurement. This is because the viscometer 15 introduces the solder paste Pst into the tubular body 152 and measures the viscosity or similar properties of the solder paste Pst. Therefore, in states A and B of Fig. 6. The solder paste Pst is inside the tubular body 152 at the time of the previous measurement, and the torque sensor 153 can detect a force absorbed by the screw 151 from the remaining solder paste Pst as torque. On the other hand, in state C of Fig. 6. The entire solder paste Pst that remained inside the tubular body 152 at the time of the previous measurement is expelled. Therefore, the viscometer 15 waits a time (reference time T1) required for the solder paste Pst from the time of the previous measurement to be expelled (at the time of the current measurement), so that a state can be created in which only the solder paste Pst at the time of the current measurement is included, without including the solder paste Pst at the time of the previous measurement. Details of the reference time T1 are described later.

[0038] The viscometer 15 begins recording the torque (torque value) via the torque sensor 153 after the reference time T1 has elapsed since the start of the measurement of the viscosity or similar property of the solder paste Pst (i.e., since the start of rotation of the motor 15M). That is, while the tubular body 152 is rotated by the motor 15M, the screw 151 experiences a force (resistance) corresponding to the viscosity of the solder paste Pst. Therefore, the force absorbed by the screw 151 is recorded as torque by the torque sensor 153. The control device 17 receives data (e.g., a torque value) regarding the torque of the screw 151 from the torque sensor 153 and measures (e.g., calculates) the viscosity or similar property of the solder paste Pst based on this data.For example, a relationship between the torque value and the viscosity or the like is known in advance, and the control device 17 can store this relationship information in a table.

[0039] In this way, the viscometer 15 takes in the solder paste Pst of a test object and measures its viscosity or other properties. The viscometer 15 is, for example, a spiral viscometer. The viscometer 15 has a structure in which, when the tubular body 152 rotates, the solder paste Pst is taken into the viscometer 15 from the inlet section 154 of the tubular body 152, then advances upwards in a spiral groove formed by the screw 151, and is finally ejected from the outlet section 155 of the tubular body 152. The torque generated by the rotation of the tubular body 152 is transmitted via the solder paste Pst to the screw 151 (shaft) with its spiral structure, and the torque exerted on the screw 151 varies depending on the viscosity of the solder paste Pst.Therefore, the printing device 1 can measure the viscosity or similar properties of the solder paste Pst using the viscometer 15. Since the torque applied to the screw 151 also changes depending on the amount of solder paste Pst, the measurement is carried out, for example, in a state where the screw 151 with the helical structure is completely filled with the solder paste Pst.

[0040] Here, the screw 151, acting as a viscometer 15, does not rotate, and the tubular body 152 rotates around the screw 151, but the present invention is not limited to this. For example, the viscometer 15 can be configured such that the screw 151 rotates and the tubular body 152 does not. That is, the viscometer 15 can be configured such that the screw 151 rotates about an axis in a direction (Z-direction) in which the screw 151 extends, the tubular body 152 surrounds the screw 151, and the tubular body 152 itself does not rotate. In this case, the torque sensor 153 can detect as torque a force (reaction force) exerted on the screw 151 by the solder paste Pst introduced into the tubular body 152.

[0041] Fig. Figure 7 is a diagram showing an example of a position in which the viscometer 15 is arranged in relation to the solder paste Pst when the viscosity or the like of the solder paste Pst is measured.

[0042] The squeegee 32 extends linearly along the X-direction. The solder paste Pst is repeatedly applied to the mask 11 by the squeegee 32. Therefore, the solder paste Pst is located on the mask 11 in a form extended in the X-direction. When the viscosity or similar properties are measured using the viscometer 15, the viscometer 15 is positioned so that it comes into contact with the solder paste Pst from above. In this case, the viscometer 15 is positioned so that it comes into contact with a section Ar2 of the solder paste Pst that extends in the X-direction, with section Ar2 bypassing a middle section Ar1 and an end section Ar3 in the X-direction. The middle section Ar1 is a section whose position in the X-direction overlaps a pattern area 11A of the mask 11.This is because the amount of solder paste Pst at the end section Ar3 may be less than at other locations along the solder paste Pst, and the amount of solder paste Pst may be insufficient for measuring viscosity or similar properties. Furthermore, this is because the middle section Ar1 is used for measuring the viscosity or similar properties of the solder paste Pst, and therefore a shape adapted by the squeegee 32 in the middle section Ar1 is broken. If the broken section passes through the opening pattern 11K during subsequent screen printing, the amount of solder paste Pst filled into the opening pattern 11K may be insufficient, resulting in a printing error. Therefore, when measuring viscosity or similar properties, it is preferable to target the solder paste Pst of section Ar2, thereby avoiding the middle section Ar1 and the end section Ar3.The viscometer 15 can be moved along a longitudinal direction of the solder paste Pst by driving the X-direction movement mechanism 16c.

[0043] Although in Fig. Figure 7 shows that the pattern area 11A of the mask 11 is formed in the central section of the mask 11; however, the present invention is not limited thereto. That is, the pattern area 11A of the mask 11 can be located at a position offset from the central section of the mask 11. In this case, the position of the solder paste that overlaps the pattern area 11A of the mask 11 in the X-direction is shifted relative to the central section Ar1. In this case, the control device 17 measures the viscosity or similar properties of the solder paste Pst at a position that avoids the end section Ar3 and at a position that overlaps the pattern area 11A of the mask 11 in the X-direction of the solder paste.

[0044] The printing device 1 can change the printing conditions based on a measurement of the viscosity or similar properties of the solder paste Pst. Accordingly, the printing device 1 can continue the printing process stably even if the solder paste Pst on the mask 11 changes over time and its viscosity changes.

[0045] Fig. Figure 8A is a block diagram showing a configuration example of a control system in the printing device 1.

[0046] The control device 1, contained in the printing device 1, performs operational control of the lifting and lowering cylinder 22, the head movement mechanism 14, the angle-of-attack change unit 33, and the viscometer movement unit 16. The control device 17 selectively raises and lowers one of the two doctor blade units 23 (i.e., one of the two doctor blades 32) relative to the base section 21 by actuating the lifting and lowering cylinder 22. The control device 17 moves the print head 13 in the Y direction by actuating the head movement mechanism 14. The control device 17 changes the angle of attack θ of the doctor blade 32 by actuating the angle of attack change unit 33. The control device 17 actuates the viscometer motion unit 16 to move the viscometer 15 in the up-down direction or the X-direction with respect to the base section 21 of the print head 13.

[0047] The viscometer 15, a thermometer 18, a temperature controller 19 and a touch panel TP are connected to the control device 17.

[0048] The viscometer 15 acquires data (for example, data regarding the torque of screw 151) corresponding to the viscosity of the solder paste Pst. The viscosity data measured by the viscometer 15 (for example, a torque value) of the solder paste Pst is input into the control device 17.

[0049] For example, the thermometer 18 is attached at any point within the printing device 1 and measures the temperature within the printing device 1 (the working space in which the printing process takes place). The temperature controller 19 maintains, increases, or decreases the temperature within the printing device 1.

[0050] As in Fig. As shown in Figure 6, the control device 17 comprises a storage unit 61, a pressure control unit 62, a timer 63, a measuring unit 64, a pressure condition change unit 66 and a temperature control unit 67.

[0051] The storage unit 61 stores at least one operating program 61a, which defines the sequence of a printing operation performed by the printhead 13, and printing condition data 61b, which consists of data on printing conditions relating to the printhead 13. The printing condition data 61b includes data on interrelationships, such as the viscosity or similar properties of the solder paste Pst, which optimizes the printing condition, the angle of attack θ, the contact force of the squeegee 32, the movement speed of the squeegee 32, and the speed at which the mask 11 and the circuit board KB are separated from each other. The storage unit 61 can store the reference time T1. The storage unit 61 can store the reference time T1 for each type of solder paste Pst. Information about the reference time T1 for each type of solder paste Pst can, for example, be stored in tabular form.Memory unit 61 can store a cleaning notification time T2 and a limit time T3, which will be described later. Memory unit 61 can store the cleaning notification time T2 and the limit time T3 for each type of solder paste Pst. Information about the cleaning notification time T2 and the limit time T3 for each type of solder paste Pst can be stored, for example, in tabular form. Details regarding the cleaning notification time T2 are described later.

[0052] The pressure control unit 62 executes the operating program 61a under the pressure conditions selected from the pressure state data 61b and carries out the printing process by actuating the lifting and lowering cylinder 22 and the head movement mechanism 14.

[0053] The timer 63 measures a predetermined time. For example, the timer 63 is used to determine whether the reference time T1, the cleaning notification time T2, the limit time T3, and the like have elapsed. The timer 63 comprises a viscometer stop timer N1 and a solder exchange timer N2. The viscometer stop timer N1 is used to measure the elapsed time since a previous measurement of the viscosity or similar properties of the solder paste Pst. The solder exchange timer N2 is used to measure the elapsed time since the start of the introduction of the solder paste Pst into the viscometer 15.

[0054] The measuring unit 64 measures the viscosity or similar property of the solder paste Pst on the mask 11, using the viscometer 15. For example, the measuring unit 64 acquires data (e.g., a torque value) regarding the torque of the screw 151 from the torque sensor 153 when the tubular body 152 of the viscometer 15 rotates, and derives (e.g., calculates) the viscosity or similar property of the solder paste Pst based on the data. For example, information about a relationship between the torque value and the viscosity or similar property can be pre-stored in the memory unit 61, and the measuring unit 64 can derive the viscosity or similar property of the solder paste Pst based on the information about the relationship and the torque data.

[0055] A measuring control unit 65 controls the motor 15M and the measuring unit 64 to perform the viscosity measurement process. The viscosity measurement process is a procedure for measuring the viscosity, or similar properties, of the solder paste Pst on the mask 11 using the viscometer 15. Details of the viscosity measurement process are described later. For example, the measuring control unit 65 causes the measuring unit 64 to derive the viscosity, or similar properties, after the reference time T1 has elapsed since the motor 15M started rotating.

[0056] The measuring control unit 65 manages the state of the viscometer 15. The state management of the viscometer 15 is performed, for example, in parallel with the viscosity measurement process. The measuring control unit 65 uses the viscometer stop timer N1 to control the viscosity, or similar properties, of the solder paste Pst inside the viscometer 15 so that it remains unchanged. The measuring control unit 65 executes the solder paste replacement process, the operating stop process, and the cleaning warning process of the printing device 1 according to a time measured by the viscometer stop timer N1.

[0057] The solder paste exchange process is a process in which the solder paste Pst remaining in the viscometer 15 is replaced by the solder paste Pst accumulated on the mask 11 by supplying the solder paste Pst accumulated on the mask 11 and ejecting the solder paste Pst remaining in the viscometer 15. The operation stop process is a process for stopping the operation (i.e., the printing process) of the printing device 1. The cleaning warning process is used to warn an operator to clean the viscometer 15. In this case, the control unit 65 can display cleaning warning information via the touch panel TP to prompt cleaning. The cleaning warning information can be presented by a different method (e.g., sound output) than the display of the warning information.

[0058] If the time measured by the viscometer stop timer N1 is equal to or shorter than the predetermined cleaning notification time T2, the measuring control unit 65 continues the normal printing process. If the time measured by the viscometer stop timer N1 is longer than the cleaning notification time T2 and equal to or shorter than the predetermined limit time T3, the measuring control unit 65 performs the solder paste replacement process. If the time measured by the viscometer stop timer N1 is longer than the limit time T3, the measuring control unit 65 performs the operating stop process and the cleaning warning process.

[0059] The cleaning notification time T2 is a point in time at which it is determined whether the operator or other person should be notified to clean the viscometer 15. This notification (cleaning notification) is less urgent than the cleaning warning. The cleaning notification time T2 is a point in time at which the viscosity or other properties of the solder paste Pst does not exceed a predetermined range, i.e., a point in time at which the viscosity or other properties are within a predetermined range. The cleaning notification time T2 could, for example, be a time (e.g., approximately one hour) during which the solder paste Pst does not deteriorate. For example, due to changes in time, the components contained in the solder paste Pst in the viscometer 15 may evaporate or the antioxidant may oxidize, causing the solder paste Pst to deteriorate and the viscosity or other properties to increase.Deterioration refers to a degree of deterioration that hinders printing, and to deterioration that makes printing via mask 11 difficult. This refers, for example, to deterioration to such an extent that the solder paste Pst has solidified into a lump.

[0060] The limit time T3 is a limit time during which the viscosity or similar property of the solder paste Pst does not exceed the predetermined range. The limit time T3 can also be described as a limit time for maintaining the viscosity of the solder paste Pst in the viscometer 15, during which a printing process can be carried out by the printing device 1. The limit time T3 is longer than the cleaning notification time T2.

[0061] The pressure condition change unit 66 modifies the pressure condition with respect to the printhead 13 as required, based on the viscosity or similar properties of the solder paste Pst, which is measured by a viscosity measuring unit 70. The pressure condition change unit 66 modifies the pressure condition, for example, by changing at least one of the following factors: angle of attack θ, the contact force of the squeegee 32, the movement speed of the squeegee 32, and the speed at which the mask 11 and the circuit board KB are separated from each other.

[0062] The temperature control unit 67 receives information about the temperature inside the printing device 1 from the thermometer 18. For example, the temperature control unit 67 instructs the temperature controller 19 to set the temperature inside the printing device 1 to a predetermined temperature, or instructs the temperature controller 19 to change (increase or decrease) the temperature inside the printing device 1 by a predetermined amount. The temperature control unit 67, together with the thermometer 18 and the temperature controller 19, controls the temperature inside the printing device 1 as needed based on the viscosity or similar properties of the solder paste Pst, which is measured by the viscosity measuring unit 70.For example, if the measured viscosity or similar property of the solder paste Pst becomes greater than at the time of the previous measurement, or if the viscosity or similar property is greater than a predetermined threshold, the temperature control unit 67 can perform a control action to increase the temperature inside the printing device 1. Conversely, if the measured viscosity or similar property of the solder paste Pst becomes less than at the time of the previous measurement, or if the viscosity or similar property is less than a predetermined threshold, the temperature control unit 67 can perform a control action to decrease the temperature inside the printing device 1.

[0063] The Touch Panel TP functions as both an operator control unit, receiving various inputs from the user, and a display unit, showing various data. For example, the Touch Panel TP displays error information if the measured viscosity or similar properties of the solder paste exceed a predefined range.

[0064] For example, if the viscosity or similar property of the solder paste Pst is not measured before the cleaning notification time T2 has elapsed since the previous measurement of the viscosity or similar property of the solder paste Pst, the Touch Panel TP can display cleaning recommendation information to advise cleaning of the viscometer 15. Similarly, if the viscosity or similar property of the solder paste Pst is not measured until the limit time T3 has elapsed since the previous measurement of the viscosity or similar property of the solder paste Pst, the Touch Panel TP can display cleaning warning information to warn the user to clean the viscometer 15. The cleaning warning information is of higher urgency and importance than the cleaning recommendation information. For example, cleaning warning information may be displayed in a more prominent format than the cleaning recommendation, such as a message.

[0065] Instead of the Touch Panel TP, the operating unit and the display unit can also be provided separately in the printing device 1. In addition to the Touch Panel TP, a loudspeaker can be provided in the printing device 1. In this case, the loudspeaker can output various types of information audibly. The display of information and the audible output are examples of the transmission and presentation of information.

[0066] Next, the reference time T1 is described in detail. The reference time T1 is the time required to replace the solder paste Pst inside the tubular body 152. That is, the reference time T1 is a time determined with reference to a time (hereinafter referred to as the ejection time) required from the time the motor 15M, which rotates the tubular body 152 to draw the solder paste Pst from the inlet section 154 of the tubular body 152, is activated, until the time the solder paste Pst is ejected from the ejection section 155 of the tubular body 152. The reference time T1 is set to a value that is longer than the ejection time, taking into account the fact that the old solder paste Pst remaining inside the tubular body 152, i.e.,The solder paste Pst, which was drawn into and remains in the tubular body 152 at the time of the previous measurement, is replaced by a new solder paste Pst. Since the measuring control unit 65 causes the measuring unit 64 to derive the viscosity or similar properties after the reference time T1, during which the tubular body 152 is reliably filled with the solder paste Pst to be measured, it is possible to measure a physical property value such as the viscosity or similar properties of the solder paste Pst on the mask 11 with high reliability. The reference time T1 is stored in the memory unit 61.

[0067] The reference time T1 can be determined based on the ejection time measured after replacing or cleaning the tubular body 152 or the screw 151. The reference time T1 used in another viscometer with the same shape or structure as the viscometer 15 can also be used as the reference time T1. The reference time T1 is set, for example, by the measuring control unit 65.

[0068] The reference time T1 can vary depending on the type of solder paste Pst. This is because the viscosity varies depending on the type of solder paste Pst, and the time the solder paste Pst takes to pass through the viscometer 15 can also vary. The memory unit 61 can store the information on the reference time T1 for each type of solder paste Pst. For example, if the memory unit 61 stores the information on the reference time T1 in advance, a measurement to derive the reference time T1 is no longer necessary.

[0069] For example, the measuring control unit 65 can specify the type of solder paste Pst used for printing via the touch panel TP, acquire the information about the reference time T1 corresponding to the solder paste type Pst, and set the reference time T1. If the information about the reference time T1 for the specified solder paste type Pst is not stored in the memory unit 61, the reference time T1 corresponding to the solder paste type Pst can be measured and stored in the memory unit 61 at the time of the first measurement of the viscosity or similar properties of this type of solder paste Pst. This allows the printing device 1 to use the information about the stored reference time T1 from the next measurement of the viscosity or similar properties of this type of solder paste Pst.

[0070] For example, the measuring control unit 65 can specify the type of solder paste Pst used for printing via the touch panel TP, acquire information about the cleaning notification time T2 and the limit time T3 according to the type of solder paste Pst, and set the cleaning notification time T2 and the limit time T3. The information about the cleaning notification time T2 and the limit time T3 for the specified type of solder paste Pst is stored in the memory unit 61.

[0071] Fig. 8B is a diagram showing an example of a table TB1 in which the information about the reference time T1 is stored.

[0072] Table TB1 stores the information on the reference time T1 for each type of solder paste Pst. In addition to the type of solder paste Pst and the reference time T1, table TB1 can store information about the rotational speed (or the number of revolutions per unit time) (also simply referred to as rotational speed) of the tubular body 152 of the viscometer 1 at the time of the viscosity measurement and the temperature in the printing device 1. That is, the reference time T1 can be determined according to the type of solder paste Pst and at least the rotational speed of the tubular body 152 or the temperature in the printing device 1. That is, the reference time T1 can be determined according to the type of solder paste Pst, the type of viscometer 15, and the ambient conditions in the printing device 1.

[0073] The rotational speed of the tubular body 152 is detected, for example, by a speed sensor (not shown) contained in the viscometer 15 and transmitted by the viscometer 15 to the measuring control unit 65. The higher the rotational speed of the tubular body 152, the higher the speed at which the solder paste Pst moves upwards within the tubular body 152; conversely, the lower the rotational speed of the tubular body 152, the lower the speed at which the solder paste Pst moves upwards within the tubular body 152. Therefore, it is estimated that the exchange rate of the solder paste Pst within the tubular body 152 is higher the higher the rotational speed. Similarly, the viscosity of the solder paste Pst is lower the higher the temperature in the printing device 1, and the higher the speed at which the solder paste Pst moves upwards within the tubular body 152.The lower the temperature in the printing device 1, the higher the viscosity of the solder paste Pst tends to be, and the lower the rotational speed at which the solder paste Pst moves upwards in the tubular body 152. Therefore, it is estimated that the exchange rate of the solder paste Pst in the tubular body 152 is higher the higher the temperature.

[0074] Fig. 8C is a diagram showing an example of a table TB2 that stores information about the cleaning notification time T2.

[0075] Table TB2 stores the cleaning notification time T2 for each type of solder paste Pst. In addition to the solder paste type Pst and the cleaning notification time T2, table TB2 can also store information about the temperature in the printing device 1. This means that the cleaning notification time T2 can be determined based on the solder paste type Pst and the temperature in the printing device 1. In other words, the cleaning notification time T2 can be determined based on the solder paste type Pst and the ambient conditions in the printing device 1.

[0076] It is assumed that the viscosity of the solder paste Pst is lower and the deterioration rate of the solder paste Pst is slower the higher the temperature in the printing device 1. It is also assumed that the viscosity of the solder paste Pst is higher and the deterioration rate of the solder paste Pst is faster the lower the temperature in the printing device 1.

[0077] Although the description of the table containing the information on the boundary time T3 has been omitted, it corresponds to the table for the cleaning notification time T2.

[0078] Next, the operation of the printing device 1 will be described using a flowchart.

[0079] Fig. Figure 9 is a flowchart showing an operating example of the printing device 1.

[0080] The control device 17 waits while monitoring whether the circuit board KB is being fed in from an upstream side of the printing device 1 (S11) and determines whether the circuit board KB is detected by a sensor (not shown) (S12). If the circuit board KB is not detected in step S12, the process continues with step S11. If the circuit board KB is detected in step S12, a circuit board transport mechanism (not shown) feeds the circuit board KB in from the upstream side (S13), and the circuit board support section 12 supports the circuit board KB. The print control unit 62 performs the print preparation process (S14).

[0081] The measuring control unit 65 determines whether it is necessary to measure the viscosity or other properties of the solder paste Pst (S15). For example, when the printing of a predetermined number of circuit boards KB is complete, it can be determined that it is necessary to measure the viscosity or other properties. If a predetermined time has elapsed since the start time (e.g., the printing start time) of the printing device 1, it can be determined that it is necessary to measure the viscosity or other properties. If a predetermined time has elapsed since the previous measurement of the viscosity or other properties, i.e., when the time measured by the viscometer stop timer N1 has reached the predetermined time, it can be determined that it is necessary to measure the viscosity or other properties.When a current time measured by timer 63 reaches a time at which the viscosity or the like is measured, which is determined by a predetermined schedule, it can be determined that it is necessary to measure the viscosity or the like.

[0082] If it is necessary to measure the viscosity or the like, the viscosity measuring unit 70 performs the viscosity measurement process (S16).

[0083] If it is not necessary to measure the viscosity or the like in step S15, or after the operation of step S16, the pressure control unit 62 performs the printing operation (S17). The pressure control unit 62 performs the plate separation operation (S18). The plate transport mechanism (not shown) carries the plate KB for which the printing operation has been completed (S19).

[0084] The print control unit 62 determines whether the production (i.e., printing) of a predetermined number of circuit boards KB is complete (S20). If the production of the predetermined number of circuit boards KB is not complete, the process continues with step S11. If the production of the predetermined number of circuit boards KB is complete, the process ends. Fig. 9.

[0085] According to the process in Fig. 9. The printing device 1 can measure the viscosity or the like of the solder paste Pst at a predetermined time while the solder paste Pst is being printed onto the circuit board KB.

[0086] Fig. Figure 10 is a flowchart showing an example of the viscosity measurement process.

[0087] The head movement mechanism 14 moves the viscometer 15 into the measuring position under the control of the control device 17 (S21). Here, the measuring position is a position in which the viscometer 15 moves downwards in the X-direction and, if necessary, comes into contact with the solder paste Pst. The measuring control unit 65 begins to drive the viscometer 15 (S22). In this case, the measuring control unit 65 starts driving the motor 15M, rotating either the screw 151 or the tubular body 152 to a state in which the screw 151 is in contact with the solder paste Pst. When the driving of the viscometer 15 is started, the control unit 65 resets the value of the solder exchange timer N2 (sets the value to 0) and begins timing with the solder exchange timer N2. The measuring control unit 65 determines whether the time measured by the solder exchange timer N2 exceeds the reference time T1 (S23).If the time measured by the solder exchange timer N2 does not exceed the reference time T1 (No in step S23), the process from step S23 is repeated.

[0088] If the time measured by the solder exchange timer N2 exceeds the reference time T1 in step S23 (Yes in step S23), the measuring unit 64 measures the viscosity or the like of the solder paste Pst introduced into the viscometer 15 (S24).

[0089] The measuring control unit 65 stops the drive of the viscometer 15 (S25). In this case, the measuring control unit 65 stops the drive of the motor 15M and stops the rotation of the screw 151 and the tubular body 152. When the drive of the viscometer 15 stops, the solder exchange timer N2 ends the time measurement. The control unit 65 resets the value of the viscometer stop timer N1 (sets the value to 0) (S26) and starts the time measurement by the viscometer stop timer N1.

[0090] The head movement mechanism 14 moves the viscometer 15, controlled by the control device 17, into a standby position (S27). The standby position is a predetermined position in which the viscometer 15 remains during a period when the viscosity or other properties of the solder paste Pst are not being measured. The pressure condition change unit 66 can change the pressure conditions based on the measured viscosity or other properties (S28). The measurement control unit 65 can issue an anomaly notification via the touch panel TP (S28). The anomaly notification can include the display of error information indicating that the measured viscosity or other properties exceed a value outside a predefined range (normal range). The anomaly notification can also be issued by means other than display (e.g., by audible signal).

[0091] According to the in Fig. In the viscosity measurement process shown in Figure 10, the pressure device 1 can complete the exchange of the solder paste Pst remaining in the viscometer 15 with the newly supplied solder paste Pst from above the mask 11 by waiting for the reference time T1 after a drive point of the viscometer 15. Since the solder paste Pst remaining in the viscometer 15 and the newly introduced solder paste Pst are not mixed, it is possible to obtain highly reliable measured values ​​for viscosity or the like.

[0092] Fig. Figure 11 is a flowchart illustrating an operational example related to viscometer state management. Viscometer state management is used to manage various states associated with viscometer 15. The process of Fig. 11 can be done in parallel to the process of Fig. 9 will be executed.

[0093] The control unit 65 determines whether the time measured by the viscometer stop timer N1 is longer than the cleaning notification time T2 (also referred to as N1 > T2) (S31). If the time measured by the viscometer stop timer N1 is not longer than the cleaning notification time T2 (No in step S31), the measuring control unit 65 proceeds to step S31.

[0094] This means that if the time measured by the viscometer stop timer N1 is no longer than the cleaning notification time T2 (No in step S31), this indicates that the time elapsed since the last measurement of the viscosity or similar properties of the solder paste Pst is shorter than the cleaning notification time T2, and that the viscosity or similar properties of the solder paste Pst are measured at intervals during which the solder paste Pst does not deteriorate. In this case, cleaning of the viscometer 15 is not required, and the printing process is carried out continuously by the pressure control unit 62.

[0095] If the time measured by the viscometer stop timer N1 is longer than the cleaning notification time T2 (Yes in step S31), the measuring control unit 65 determines whether the time measured by the viscometer stop timer N1 is longer than the limit time T3 (also referred to as N1 > T3) (S32).

[0096] If the time measured by the viscometer stop timer N1 is not longer than the limit time T3 (No in step S32), the measuring control unit 65 performs the solder paste replacement process (S33).

[0097] This means that in step S33, since the cleaning notification time T2 has elapsed since the previous measurement of the viscosity or similar properties of the solder paste Pst, there is a possibility that the solder paste Pst has deteriorated afterwards, and therefore the measuring control unit 65 performs the solder paste replacement process. As described later, the solder paste replacement process also serves to measure the viscosity or similar properties of the next solder paste Pst.

[0098] If the time measured by the viscometer stop timer N1 is longer than the limit time T3 (Yes in step S32), the measuring control unit 65 performs the operating stop procedure and the cleaning warning procedure (S34).

[0099] As described above, sufficient time remains before the cleaning notification time T2 expires since the last measurement of the viscosity or similar properties of the solder paste Pst before the solder paste Pst deteriorates in the viscometer 15. Therefore, the printing device 1 can continue the normal printing process. If the cleaning notification time T2 has expired since the previous measurement of the viscosity or similar properties of the solder paste Pst, the solder paste Pst may subsequently deteriorate in the viscometer 15. On the other hand, the printing device 1 can expel the solder paste Pst remaining in the viscometer 15 by performing the solder paste exchange process. Therefore, a highly reliable measurement can be obtained with the new solder paste Pst when the new solder paste Pst is used.Furthermore, if the limit time T3 has elapsed since the previous measurement of the viscosity or similar properties of the solder paste Pst, there is a high probability that the solder paste Pst will subsequently deteriorate in the viscometer 15. On the other hand, the printing device 1 can prevent the failure of the viscometer 15 and the failure of other components within the printing device 1 by stopping the printing process without performing the solder paste replacement procedure. At this point, the printing device 1 can indicate the urgent need to clean the viscometer 15 by executing the cleaning warning procedure.

[0100] Fig. Figure 12 is a flowchart showing an example of the solder paste replacement process.

[0101] The measuring control unit 65 determines whether the solder paste replacement process is possible (S41). For example, if an element used for the solder paste replacement process (e.g., the mask 11 or the viscometer 15) is installed at a predetermined position in the printing device 1, it is determined that the solder paste replacement process is possible. Conversely, if, for example, the element used for the solder paste replacement process is not installed at a predetermined position in the printing device 1 (e.g., if the element has been removed), it is determined that the solder paste replacement process is not possible.

[0102] If the solder paste replacement process is possible (Yes in step S41), the printing device 1 performs the following steps: Fig. The processes shown in steps S22 to S27 are executed as follows: Here, the printing device 1 does not perform the process of step S28.

[0103] If the solder paste replacement process is not possible (No in step S41), the measuring control unit 65 issues a viscometer cleaning notification via the Touch Panel TP (S42). The viscometer cleaning notification is a notification containing cleaning recommendation information that suggests cleaning the viscometer 15. The cleaning recommendation information can be presented by a method other than display (e.g., sound output). For example, the measuring control unit 65 notifies a person operating the unit of the cleaning recommendation information or notifies a robotic device of the cleaning recommendation information.

[0104] Therefore, the operator can, for example, remove and clean at least part (e.g., the tubular body 152) of the viscometer 15 from the printing device 1 by checking the cleaning recommendation information.

[0105] Since the printing device 1 according to the in Fig. In the solder paste exchange process shown in Figure 12, the solder paste Pst remaining in viscometer 15 from the previous measurement can be replaced by the new solder paste Pst. This prevents the solidification of the solder paste Pst in viscometer 15. Therefore, a highly reliable measurement of viscosity or similar properties can be obtained. Furthermore, since the viscosity or similar properties of the newly introduced solder paste Pst can be measured when the solder paste Pst is exchanged, the measurement efficiency is high.

[0106] In the events in the Fig. For example, in steps 9 to 12, the printing device 1 starts the viscosity measurement process (step S16 in Fig. 9 and steps S21 to S28 in Fig. 10) in a state in which the solder paste Pst remains in the viscometer 15 at the time of the previous measurement. The pressure device 1 forces the solder paste Pst of a previous measurement object out of the viscometer 15 through the solder paste Pst of a current measurement object during the viscosity measurement process itself.

[0107] The printing device 1 calculates the viscosity or the like of the solder paste Pst by using a value (torque value) output by the viscometer 15 after a sufficient time (reference time T1) has elapsed to replace the solder paste Pst inside the viscometer 15 since the start of the viscosity measurement process.

[0108] In the viscometer 15, for example in the case of a spiral viscometer, a liquid (for example, the solder paste Pst) with high viscosity, in which the solder paste Pst moves in one direction from the inlet section 154 to the outlet section 155 and is forced upwards, is the object being measured. Therefore, the solder paste Pst of the current object being measured, which has been taken into the viscometer 15, is filled into the viscometer 15 (tubular body 152). While the solder paste Pst of the current object being measured is being filled, the solder paste Pst of the previous object being measured can be forced out of the viscometer 15.

[0109] For example, the printing device 1 measures as reference time T1 the time from the start of the introduction of the solder paste Pst from the introduction section 154 of the viscometer 15 until the start of the ejection of the solder paste Pst from the ejection section 155 of the viscometer 15 in a state in which the viscometer 15 has been cleaned. That is, the reference time T1 is the time required at the time of the first measurement of the viscosity or similar by the printing device 1 until the viscometer 15 is filled with a required amount of the solder paste Pst, and the viscosity or similar of the solder paste Pst inside the viscometer 15 assumes a constant value, for example, becoming the value of the viscosity or similar of the solder paste Pst during the measurement. The reference time T1 corresponds to an exchange time of the solder paste Pst in the viscometer 15.Therefore, the printing device 1 can be measured by measuring the solder paste Pst after the reference time T1 has elapsed from the beginning of the viscosity measurement process (for example, the beginning of the drive of the viscometer 15 in step S22 of . Fig. 10) reliably replace the liquid of a difficult-to-observe object and measure the viscosity or similar properties of the liquid of the current object.

[0110] The printing device 1 can prevent deterioration of the solder paste Pst adhering to the viscometer 15 by periodically measuring the viscosity or similar parameters when the cleaning notification time T2 has elapsed since the last measurement. If the cleaning notification time T2 or more has elapsed since the last measurement of the viscosity or similar parameters, the printing device 1 displays information prompting the cleaning of the viscometer 15 (e.g., the cleaning recommendation information) to inform the operator that cleaning of the viscometer 15 is required (step S33 in Fig. 11 and step S42 in Fig. 12) This display may, for example, include at least one voice output via a loudspeaker or a screen display via the TP touch panel. This display may be for the operator. By checking the cleaning recommendation information and cleaning the viscometer 15, the operator can prevent the deterioration of the liquid adhering to the viscometer 15.

[0111] As described above, according to the pressure device 1 of the present embodiment, the viscosity or similar property of the solder paste Pst can be measured periodically within the pressure device 1. At this point, the pressure device 1 replaces the solder paste Pst inside the viscometer 15 (inside the tubular body 152) by forcing out the old solder paste Pst of the previous object being measured, which is still inside the viscometer 15, along with the new solder paste Pst of the current object being measured. The pressure device 1 can derive the viscosity or similar property of the solder paste Pst of the current object being measured from a measured value (torque value) for the solder paste Pst after the replacement. The solder paste Pst is an example of the object to be measured, and another liquid medium could be the object to be measured.

[0112] According to the printing device 1 of the present embodiment, the viscosity or similar property of the solder paste Pst is measured when the cleaning notification time T2, which is shorter than the time during which the solder paste Pst adhering to the viscometer 15 deteriorates, has elapsed since the previous measurement of the viscosity or similar property. Accordingly, the printing device 1 can prevent deterioration of the solder paste Pst adhering to the viscometer 15. At this time, the printing device 1 transmits the cleaning recommendation information. This transmission is, for example, a presentation to a person and can include at least a voice output via a loudspeaker SP or a screen display via the touch panel TP. The transmission can, for example, include the transmission of command information to request a robot to clean.

[0113] If the limit time T3 has elapsed since the previous measurement, a failure of the viscometer 15 or other devices in the printing device 1 can be avoided by stopping the printing process. At this point, the printing device 1 can inform the operator or a similar person of the urgency of cleaning by transmitting the cleaning warning information.

[0114] The printing device 1 periodically measures the viscosity or similar parameters, or outputs cleaning recommendation information, before the solder paste Pst deteriorates, without providing a cleaning unit that automatically cleans the interior of the viscometer 15. Therefore, it is possible to prevent an increase in the cost of the printing device 1 and a reduction in the operating rate during cleaning. Furthermore, since the old solder paste Pst is drawn out of the viscometer 15 by refilling its interior during periodic viscosity measurements, it is possible to prevent a reduction in the measurement accuracy of the viscosity or similar parameters.Furthermore, if the viscosity or similar parameters cannot be measured regularly, for example, if the limit time T3 is not met due to a device stoppage such as a pause, the printing device 1 stops the printing process and displays the cleaning warning information. Therefore, the operator can recognize the need for cleaning, and by removing and cleaning the viscometer 15, it is possible to prevent deterioration of the quality of the object being measured and failure of the viscometer 15. In addition, the viscometer cleaning notification (step S42 in . Fig. 12) according to the time elapsed since the last measurement of viscosity or the like, whereupon the cleaning warning process (step S34 in Fig. 11) can be carried out. That is, the printing device 1 can provide information for cleaning the viscometer 15 in several steps.

[0115] Therefore, the printing device 1 can prevent a deterioration in the quality of the solder paste Pst of the object being measured, prevent the solidification of the solder paste Pst adhering to the inside of the viscometer 15, and prevent the failure of the viscometer 15. (Summary of the exemplary implementation)

[0116] As described above, at least the following matters are described in the present disclosure. Components corresponding to those in the above embodiment are shown in parentheses, but the present disclosure is not limited thereto. [Item 1]

[0117] Printing device (printing device 1) which prints a solder paste (solder paste Pst) over a mask (mask 11) with a predetermined opening pattern (opening pattern 11K) onto a circuit board (circuit board KB), the printing device comprising: a viscosity measuring unit (viscosity measuring unit 70) configured to measure the viscosity of the solder paste, wherein the viscosity measuring unit includes a suction section (viscometer 15) comprising a tubular body (tubular body 152) having an opening (ejection section 155) configured to draw the solder paste into contact with a suction opening (introduction section 154), and a screw (screw 151) contained within the tubular body, a motor (motor 15M) configured to rotate the screw or tubular body in a state where the screw is in contact with the solder paste, a measuring unit (measuring unit 64) configured to detect a torque acting on the screw or tubular body and to measure the viscosity or a viscosity equivalent value of the solder paste based on the torque, and a control unit (measuring control unit 65) configured to control the motor, and The measuring unit measures the viscosity or viscosity equivalent value based on the torque, which is recorded after a time specified by the control unit during which the motor rotates.

[0118] Accordingly, the pressure device can expel the solder paste from the previous object being measured, which remains in the suction section, by rotating the motor for a predetermined time. Upon subsequent initiation of the measurement, the solder paste adhering to the screw becomes the solder paste of the current object being measured. Therefore, the pressure device can obtain a highly reliable measurement during circuit board manufacturing by preventing the solder paste of the previous object from mixing with the solder paste of the current object, and can improve the measurement accuracy of the solder paste's viscosity or other properties. As described above, the pressure device can prevent a reduction in the measurement accuracy of viscosity or other properties, even when the viscosity or other properties of an object being measured are measured within the suction section. [Item 2]

[0119] Printing device according to item 1, wherein the predetermined time is longer than the time between the moment the motor starts to rotate via the control unit and the moment the solder paste adhering to the screw is ejected from the opening.

[0120] Accordingly, the printing device waits longer than the time required to eject the solder paste from the opening to measure the solder paste, so that the solder paste of the previous object being measured, which remains in the suction section, can be reliably replaced by the solder paste of the current object being measured, and the viscosity or similar properties of the solder paste can be measured. [Item 3]

[0121] Printing device according to item 1 or 2, wherein The viscosity or viscosity equivalent value of the solder paste is measured while the suction section moves along the solder paste, which is scraped off the mask by a squeegee.

[0122] On the other hand, in the pressure device, the suction section moves along the solder paste (in the X direction), thus preventing the solder paste from being repeatedly introduced into the suction section at the same position, ensuring that the solder paste of the object being measured is insufficient, and allowing the viscosity or similar properties to be measured appropriately and easily. [Item 4]

[0123] Printing device according to one of items 1 to 3, wherein The viscosity measuring unit measures the viscosity or viscosity equivalent value of the solder paste at a position (section Ar2) that avoids a position (middle section Ar1) that overlaps a pattern area (pattern area 11A) of the mask in the longitudinal direction of the solder paste that is scraped off the mask by a squeegee and an end section (end section Ar3) of the solder paste in the longitudinal direction.

[0124] Accordingly, the printing device can measure the viscosity at a point where sufficient solder is present by measuring the viscosity while avoiding the end section in the longitudinal direction of the solder paste. Furthermore, the printing device measures the viscosity while avoiding the position that overlaps the pattern area of ​​the mask in the longitudinal direction of the solder paste, thus avoiding a situation where the amount of solder to be printed onto the board is insufficient, which would otherwise require scraping off solder paste for viscosity measurement. [Item 5]

[0125] Viscosity measurement method for measuring the viscosity of a solder paste printed onto a circuit board using a suction section via a mask with a predetermined opening pattern. wherein the suction section comprises a tubular body with an opening configured to draw in the solder paste into contact with a suction opening, and a screw contained within the tubular body, the viscosity measurement method includes: a rotation step in which the screw or tubular body is rotated by a motor in a state where the screw is in contact with the solder paste; and a measuring step for detecting a torque acting on the screw or tubular body and for measuring the viscosity or a viscosity equivalent value of the solder paste based on the torque, wherein The measurement step includes a step to measure the viscosity or viscosity equivalent value based on the torque recorded after a predetermined time of rotating the motor in the rotary step.

[0126] Accordingly, the viscosity measurement method can achieve the same effect as the method according to Item 1. [Item 6]

[0127] Viscosity measurement method according to item 5, wherein the predetermined time is longer than the time between the moment the motor starts to rotate and the moment the solder paste adhering to the screw is ejected from the opening.

[0128] This allows the viscosity measurement method to achieve the same effect as with item 2. [Item 7]

[0129] Viscosity measurement method according to claim 5 or 6, wherein The measurement step includes a step to measure the viscosity or viscosity equivalent value of the solder paste, while the suction section moves along the solder paste, which is scraped off the mask by a squeegee.

[0130] This allows the same effect to be achieved with the viscosity measurement method as with item 3. [Item 8]

[0131] Viscosity measurement method according to one of claims 5 to 7, wherein The measurement step includes a step to measure the viscosity or viscosity equivalent value of the solder paste at a position that avoids a position that overlaps a pattern area of ​​the mask in the longitudinal direction of the solder paste that is scraped off the mask by a squeegee and an end section of the solder paste in the longitudinal direction.

[0132] Accordingly, the same effect as with item 4 can be achieved using the viscosity measurement method.

[0133] Although the embodiment described above was described with reference to the accompanying drawings, the present disclosure is not limited thereto. It is obvious to the person skilled in the art that various modifications, corrections, replacements, additions, deletions, and equivalents are conceivable within the scope described in the claims, and it is understood that such modifications, corrections, replacements, additions, deletions, and equivalents also fall within the technical scope of the present disclosure. Furthermore, components in the embodiment described above can be freely combined within a given area without departing from the spirit of the invention.

[0134] The present application is based on a Japanese patent application (Japanese patent application no. 2023-114701) filed on July 12, 2023, the contents of which are hereby incorporated by reference. Industrial applicability

[0135] The present disclosure is useful for a printing device, a viscosity measurement method and the like, with which a highly reliable measurement can be obtained during the manufacture of a circuit board. Reference symbol list 1 Printing device 11 Mask 11K Opening Pattern 13 Printhead 15 Viscometers 15M Motor 18 Thermometer 151 screw 152 tubular bodies 153 Torque sensor 154 Introductory section 155 Ejection section 32 squeegees 64 Unit of measurement 65 Measuring control unit 67 Temperature control unit 70 viscosity measuring unit KB board Pst solder paste TP Touch Panel QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] JP 2008-307864A

[0003]

Claims

[1] Printing device which prints a solder paste onto a circuit board via a mask with a predetermined opening pattern, wherein the printing device comprises the following a viscosity measuring unit configured to measure the viscosity of the solder paste, the viscosity measurement unit comprises: a suction section comprising a tubular body having an opening and configured to draw in the solder paste into contact with a suction opening, and a screw contained within the tubular body; a motor configured to rotate the screw or tubular body in a state where the screw is in contact with the solder paste; a measuring unit configured to detect a torque acting on the screw or tubular body and to measure the viscosity or a viscosity equivalent value of the solder paste based on the torque; and a control unit configured to control the motor, and wherein the measuring unit measures the viscosity or viscosity equivalent value based on the torque recorded after a time specified by the control unit during which the motor rotates. [2] Printing device according to claim 1, wherein the predetermined time is longer than the time between the time at which the motor starts to rotate by the control unit and the time at which the solder paste adhering to the screw is ejected from the opening. [3] Printing device according to claim 1 or 2, wherein the viscosity or viscosity equivalent value of the solder paste is measured while the suction section moves along the solder paste, which is scraped off the mask by a squeegee. [4] Printing device according to claim 1 or 2, wherein the viscosity measuring unit measures the viscosity or viscosity equivalent value of the solder paste at a position that avoids a position that overlaps a pattern area of ​​the mask in the longitudinal direction of the solder paste that is scraped off the mask by a squeegee and an end section of the solder paste in the longitudinal direction. [5] Viscosity measurement method for measuring the viscosity of a solder paste printed onto a circuit board via a mask with a predetermined opening pattern using a suction section, wherein the suction section comprises a tubular body with an opening configured to draw in the solder paste into contact with a suction opening, and a screw contained within the tubular body, the viscosity measurement method exhibits: a rotation step in which the screw or tubular body is rotated by a motor in a state where the screw is in contact with the solder paste; and a measuring step to detect a torque acting on the screw or tubular body and to measure the viscosity or a viscosity equivalent value of the solder paste based on the torque, wherein the measuring step includes a step to measure the viscosity or viscosity equivalent value based on the torque recorded after a predetermined time of rotating the motor in the rotary step. [6] Viscosity measurement method according to claim 5, wherein the predetermined time is longer than the time between the time at which the motor starts to rotate and the time at which the solder paste adhering to the screw is ejected from the opening. [7] Viscosity measurement method according to claim 5 or 6, wherein the measurement step comprises a step to measure the viscosity or viscosity equivalent value of the solder paste while the suction section moves along the solder paste which is scraped off the mask by a squeegee. [8] Viscosity measurement method according to claim 5 or 6, wherein the measurement step comprises a step for measuring the viscosity or viscosity equivalent value of the solder paste at a position which avoids a position which overlaps a pattern area of ​​the mask in the longitudinal direction of the solder paste which is scraped off by a squeegee on the mask and an end section of the solder paste in the longitudinal direction.

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