Printing device and printing method

Abstract

To provide a printing device that can suppress operation rates in a printing process from decreasing, by improving performance in maintaining and managing a conveying belt.SOLUTION: A printing device 1, which prints a solder paste on a substrate using a mask having a predetermined opening formed, comprises: a substrate holding part that holds the substrate to align the substrate with the opening; a printing head that prints the solder paste on the substrate by filling the opening with the solder paste; a conveying part that conveys the substrate placed on a belt up to the substrate holding part and conveys the substrate on which the paste is completely printed to a downstream side; a detecting part that detects the substrate conveyed by the conveying part; and a determining part that measures a time during which the substrate is conveyed by a predetermined distance by the conveying part, on the basis of a result of detection performed by the detecting part, and determines a state of the belt, on the basis of the measured time.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present disclosure relates to a printing device and a printing method. [Background technology]

[0002] Conventionally, component mounting devices that mount electronic components on substrates (e.g., printed circuit boards) and printing devices that print solder paste on the substrates using a mask or the like with predetermined openings are known. The component mounting devices and printing devices are equipped with a board conveying device (hereinafter also referred to as a conveying unit) for sequentially conveying the boards. When the board conveying device conveys the boards, it is required to position them accurately in each mounting process. However, if the conveying belt (hereinafter also referred to as the "belt") deteriorates over time or solder paste adheres to the conveying belt, resulting in variations in conveying speed, the positioning accuracy may decrease. Therefore, appropriate maintenance management is performed on the printing device, including the conveying belt, as needed.

[0003] Regarding the maintenance of conveyor belts, a conveyor device that allows the conveyor belt to be replaced is known (see, for example, Patent Document 1). This substrate conveyor device includes a drive shaft that is connected to a single rotary drive source and drives each of a pair of drive pulleys for a pair of conveyor rails on the same axis. The drive shaft is configured with a pair of split shaft ends that are at least partially separated in the axial direction, and a shaft coupling that allows the split shaft ends to be freely separated and connected. This configuration makes it possible to freely detach the conveyor belt from the split portion when the shaft coupling is separated. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-67348 Summary of the Invention [Problem to be solved by the invention]

[0005] In the substrate transport device of Patent Document 1, the condition of the transport belt can only be visually ascertained by an operator when the transport belt is replaced. In other words, the condition of the transport belt during operation is not ascertained or inspected in real time. Therefore, it is difficult to predict the time to replace the transport belt in advance, and there is room for improvement. Furthermore, the substrate transport device of Patent Document 1 does not take into consideration the maintenance of the transport belt.

[0006] The present disclosure provides a printing apparatus and a printing method that can improve the maintainability of a conveyor belt and suppress a decrease in the availability rate of a printing process. [Means for solving the problem]

[0007] One aspect of the present disclosure provides a printing device that prints solder paste on a substrate using a mask with predetermined openings formed therein, the printing device comprising: a substrate holding unit that holds the substrate and aligns it with the opening; a print head that fills the opening with the solder paste and prints the solder paste on the substrate; a transport unit that transports the substrate placed on a belt to the substrate holding unit and transports the substrate downstream after printing is complete; a detection unit that detects the substrate being transported by the transport unit; and a judgment unit that measures the time it takes for the substrate to be transported a predetermined distance by the transport unit based on the detection result of the detection unit and judges the condition of the belt based on the measured time.

[0008] One aspect of the present disclosure is a printing method for printing solder paste on a substrate using a mask having predetermined openings formed therein, the printing method comprising: a substrate holding step for holding the substrate using a substrate holding unit and aligning it with the opening; a printing step for filling the opening with the solder paste and printing the solder paste on the substrate; a transport step for transporting the substrate placed on a belt to the substrate holding unit and transporting the substrate downstream after printing is complete; a detection step for detecting the substrate being transported in the transport step; and a determination step for measuring the time it takes for the substrate to be transported a predetermined distance in the transport step based on the detection result in the detection step, and determining the state of the belt based on the measured time. [Effects of the Invention]

[0009] According to the present disclosure, the maintainability of the transport belt can be improved, and a decrease in the operating rate of the printing process can be suppressed. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a diagram illustrating an example of the configuration of a printing device according to an embodiment of the present disclosure, viewed along the conveyance direction of a substrate; [Figure 2] A diagram showing the configuration example of the printing device in Figure 1, viewed in a direction perpendicular to the substrate transport direction. [Figure 3] FIG. 1 is a diagram illustrating the installation positions of transmission type sensors or reflection type sensors on the carry-in conveyor section, the positioning conveyor section, and the carry-out conveyor section. [Figure 4] A block diagram illustrating an example of the configuration of a control system of the printing apparatus of FIG. 1. [Figure 5] FIG. 10 is a diagram illustrating an example of an allowable range for determining the conveyance state of a conveyor belt. [Figure 6] FIG. 10 is a diagram illustrating an example of calculation of theoretical values ​​and measured values ​​regarding the transport time in the carry-in conveyor section. [Figure 7] FIG. 10 is a diagram illustrating an example of calculation of theoretical values ​​and measured values ​​regarding the transport time in the positioning conveyor section. [Figure 8] FIG. 10 is a diagram illustrating an example of calculation of theoretical values ​​and measured values ​​regarding the transport time in the discharge conveyor section. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, with reference to the accompanying drawings, detailed descriptions of embodiments specifically disclosing a printing apparatus and a printing method according to the present disclosure will be provided. However, unnecessary detailed descriptions may be omitted. For example, detailed descriptions of well-known matters or redundant descriptions of substantially identical configurations may be omitted. This is to avoid unnecessary redundancy in the following description and to facilitate understanding by those skilled in the art. Furthermore, each of the accompanying drawings will be referenced according to the orientation of the reference numerals.

[0012] The accompanying drawings and the following description are provided to enable those skilled in the art to fully understand the present disclosure, and are not intended to limit the subject matter described in the claims.

[0013] Furthermore, the term "unit" or "device" in the embodiments is not limited to a physical configuration mechanically realized by hardware, but also includes a configuration whose functions are realized by software such as a program. Furthermore, the functions of one configuration may be realized by two or more physical configurations, or the functions of two or more configurations may be realized by, for example, one physical configuration.

[0014] In the following, the substrate transport direction is defined as the X direction, the direction perpendicular to the X direction in a horizontal plane as the Y direction, and the direction perpendicular to the XY plane as the Z direction. The Z direction is also referred to as the "vertical direction," the positive side of the Z direction as "up," and the negative side of the Z direction as "down."

[0015] (First embodiment) A first embodiment of the present disclosure will be described with reference to FIGS.

[0016] [Basic configuration of the printing device] The hardware configuration of a printing device 1 according to this embodiment will be described with reference to Fig. 1. Fig. 1 is a diagram showing an example of the configuration of a printing device 1 according to this embodiment as viewed along the transport direction of a substrate 2.

[0017] 1, the printing device 1 has a function of printing a solder paste P such as cream solder or conductive paste onto a substrate 2 using a screen mask 13 (an example of a mask, see below) formed with predetermined pattern holes 13h (an example of an opening, see below). The printing device 1 is exemplified by a screen printing machine, for example.

[0018] The printing apparatus 1 includes a substrate holding table 4 (an example of a substrate holding section) and a substrate holding table moving mechanism 5.

[0019] The substrate holding table 4 clamps, fixes, and holds the substrate 2 that has been transported from upstream by a substrate transport mechanism 6 (an example of a transport unit, see below). The substrate holding table moving mechanism 5 is capable of moving the substrate holding table 4 in the X and Y directions, and also moving (raising and lowering) the substrate holding table 4 in the Z direction. The substrate holding table 4 and the substrate holding table moving mechanism 5 can operate integrally with a positioning conveyor unit 6B (see below) of the substrate transport mechanism 6.

[0020] Furthermore, the substrate holding table moving mechanism 5 is capable of rotationally moving the substrate holding table 4 in a predetermined rotation direction θ within the XY plane. Therefore, the substrate holding table 4 is freely movable in the X direction (bx direction), Y direction (by direction), and Z direction (bz direction) and is freely rotatable in the rotation direction θ (bθ direction). By driving the substrate holding table moving mechanism 5, the substrate holding table 4 adjusts the position and orientation of the substrate holding table 4, i.e., the position and orientation of the substrate 2, thereby determining and aligning the position of the substrate 2 with respect to the screen mask 13 (specifically, the pattern holes 13h of the screen mask 13).

[0021] The substrate 2 is carried in from the upstream side by a carry-in conveyor section 6A (see below) of the substrate transport mechanism 6, and is positioned by a positioning conveyor section 6B (see below) of the substrate transport mechanism 6. Then, after printing on the substrate 2, the substrate 2 is carried out downstream by an unloading conveyor section 6C (see below) of the substrate transport mechanism 6.

[0022] The printing device 1 further includes a screen mask 13 , a print head 14 , a print head moving mechanism 15 , and a squeegee 16 .

[0023] A flexible screen mask 13 is stretched over the mask frame 13a. A plurality of pattern holes 13h are formed in the screen mask 13 in accordance with the shapes or positions of electrodes and other objects to be printed on the substrate 2. Solder paste P is supplied onto the screen mask 13 by a paste supply mechanism (not shown). The solder paste P contains a sticky flux. A print head 14 is disposed on the screen mask 13.

[0024] The print head 14 fills the pattern holes 13h with solder paste P and prints the solder paste P on the substrate 2. The print head 14 also has a squeegee lifting mechanism (not shown) that moves the squeegee 16 up and down.

[0025] The squeegees 16 are provided in pairs along the Y direction. The squeegees 16 are formed in an elongated shape with the X direction as the longitudinal direction. The squeegees 16 are raised and lowered in the Z direction by driving a squeegee lifting mechanism. That is, one squeegee 16 rises and lowers in the a1 direction, and the other squeegee 16 rises and lowers in the a2 direction. When the squeegees 16 are lowered, the squeegee 16 comes into contact with the upper surface of the screen mask 13. The squeegee 16 comes into contact with the screen mask 13 and slides over the upper surface of the screen mask 13, thereby printing the solder paste P onto the substrate 2 through the pattern holes 13h of the screen mask 13. When the squeegee 16 is raised, the squeegee 16 is released from contact with the upper surface of the screen mask 13.

[0026] The print head moving mechanism 15 moves the print head 14 along the Y direction. The print head 14 is freely movable in the Y direction (ay direction) by being driven by the print head moving mechanism 15. As a result, the squeegee 16 attached to the print head 14 moves in the Y direction and prints the solder paste P onto the substrate 2 through the pattern holes 13h of the screen mask 13.

[0027] The printing device 1 further includes a camera unit 26 .

[0028] A camera unit 26 is disposed below (behind) the screen mask 13. The camera unit 26 is attached to a camera unit moving mechanism 34 (described later), and is movable in the X direction (cx direction) and the Y direction (cy direction) by the camera unit moving mechanism 34.

[0029] The camera unit 26 includes a camera 26c and a prism 26p. The camera 26c functions as a substrate recognition imaging unit that captures an image of the substrate 2 from above, and as a mask recognition imaging unit that captures an image of the screen mask 13 from the lower surface 13c side.

[0030] Camera 26c may have these two functions as a single camera, or as two cameras. Prism 26p disperses, refracts, or reflects light to enable imaging of lower surface 13c of screen mask 13 and upper surface of substrate 2. Camera unit 26 moves horizontally along the X and Y directions to simultaneously capture images of substrate 2 and screen mask 13, thereby recognizing substrate 2 and screen mask 13 simultaneously.

[0031] The printing device 1 may further include a cleaning unit 27 .

[0032] A cleaning unit 27 is disposed below (behind) the screen mask 13. Note that the standby positions of the camera unit 26 and the cleaning unit 27 when they are not in use are, for example, on both sides of the screen mask 13 along the Y direction, but are not limited to this.

[0033] The cleaning unit 27 cleans (mask cleans) the lower surface 13c of the screen mask 13. The cleaning unit 27 has a cleaning function and removes the solder paste P adhering to the lower surface 13c of the screen mask 13, or the solder paste P remaining in the pattern holes 13h without being transferred to the substrate 2.

[0034] The cleaning unit 27 may include a blade 42 , a blade holder 38 , and a cleaning unit movement base 35 .

[0035] The blade 42 comes into contact with the lower surface 13c of the screen mask 13 and scrapes off the solder paste P. The blade holder 38 holds the blade 42. The cleaning unit movement base 35 holds the blade holder 38. The blade holder 38 may or may not be raised and lowered in the Z direction by driving an elevation mechanism (not shown). The cleaning unit 27 is attached to a cleaning unit movement mechanism 36 (see below) and is movable in the Y direction (dy direction) via the cleaning unit movement mechanism 36.

[0036] The cleaning unit 27 performs mask cleaning during periods when printing of solder paste P using the screen mask 13 is not being performed. During periods when mask cleaning is being performed, the cleaning unit 27 is positioned in an area A1 below the screen mask 13 by driving a cleaning unit moving mechanism 36. On the other hand, during periods when mask cleaning is not being performed, the cleaning unit 27 is positioned and waits in a waiting area A2 adjacent to the area A1 below the screen mask 13. The waiting area A2 is positioned at a position that does not overlap with the screen mask 13 when the printing apparatus 1 is viewed in a plan view from above.

[0037] The printing apparatus 1 may further include a blade cleaning unit 50 and a blade cleaning unit moving mechanism 51.

[0038] The blade cleaning unit 50 cleans the blade 42 included in the cleaning unit 27. The blade cleaning unit moving mechanism 51 is disposed extending along the X direction and has a mechanism for moving the blade cleaning unit 50 along the X direction. Therefore, the blade cleaning unit 50 is freely movable along the X direction (ex direction). During the period in which the blade cleaning unit 50 cleans the blade 42, the blade cleaning unit 50 cleans the blade 42 while moving, for example, from one end of the blade 42 to the other along the X direction. During the period in which the blade cleaning unit 50 is not cleaning the blade 42, the blade cleaning unit 50 is positioned, for example, at the positive end in the X direction and waits. The period in which the blade 42 is cleaned is not the period in which mask cleaning is performed, but is included in the period in which the cleaning unit 27 is positioned in the waiting area A2 at the end in the Y direction.

[0039] [Configuration of the substrate transport mechanism] The configuration of the substrate transport mechanism 6 will be described with reference to Figures 2 and 3. Figure 2 is a diagram showing an example of the configuration of the printing apparatus 1 in Figure 1 viewed in a direction perpendicular to the substrate transport direction. Figure 3 is a diagram showing an example of the mounting positions of the transmission sensors 65A and 65C and the reflection sensor 65B on the loading conveyor unit 6A, the positioning conveyor unit 6B, and the unloading conveyor unit 6C, respectively.

[0040] 2, the substrate transport mechanism 6 is made up of three independent transport units, which transport substrates 2 on the left side of the paper in the left-right direction in Fig. 2, then continuously transport substrates 2 in the center in the left-right direction, and again continuously transport substrates 2 on the right side. That is, the substrate transport mechanism 6 is made up of an infeed conveyor unit 6A, a positioning conveyor unit 6B, and an unfeed conveyor unit 6C, and these transport units work together to continuously transport substrates 2.

[0041] The carry-in conveyor unit 6A receives the substrate 2 from an external device located upstream of the printing apparatus 1 and transports it into the apparatus. The positioning conveyor unit 6B operates integrally with the substrate holding table 4 and substrate holding table moving mechanism 5 described above. That is, the positioning conveyor unit 6B receives the substrate 2 from the carry-in conveyor unit 6A, transports it to the substrate holding table 4 and substrate holding table moving mechanism 5, and positions it with respect to the screen mask 13. The carry-out conveyor unit 6C transports the substrate 2, which has been positioned with respect to the screen mask 13 by the positioning conveyor unit 6B and has completed printing, to an external device located downstream of the apparatus.

[0042] The carry-in conveyor 6A, positioning conveyor 6B, and carry-out conveyor 6C are arranged in order along the conveying direction so that their conveying directions coincide with each other. Each of the carry-in conveyor 6A, positioning conveyor 6B, and carry-out conveyor 6C has a similar structure, and is configured to include a pair of conveyor belts 61, a plurality of driven pulleys 62 and drive pulleys 63, and a pair of holding chutes 64.

[0043] The pair of conveyor belts 61 are arranged parallel to each other, have a two-row structure, and hold both edge portions of the substrate 2. The conveyor belt 61 is made of a flexible material such as rubber, resin, or a resin-coated fiber material, and is formed in an endless loop (circulation). A plurality of driven pulleys 62 are rotatably supported on a base, and the drive pulley 63 is fitted to a drive shaft that is rotatably supported on a bearing device fixed to the base. Each of the pair of conveyor belts 61 is stretched around the plurality of driven pulleys 62 and the drive pulley 63.

[0044] When a drive motor (not shown) rotates and drives a drive shaft (not shown), the pair (two rows) of conveyor belts 61 circulates, and the upper and lower rows of the conveyor belts 61 move along the conveying direction at the same speed. Due to this movement, the substrate 2 placed on the upper side of the pair of conveyor belts 61 is conveyed along the conveying direction in each of the carry-in conveyor section 6A, the positioning conveyor section 6B, and the carry-out conveyor section 6C. In addition, a pair of holding chutes 64 are arranged on both sides in the conveying direction, and sandwich the substrate 2 from the sides to guide the substrate 2. As a result, the substrate 2 is conveyed while being held in a predetermined posture on the upper side of the conveyor belts 61.

[0045] The drive motor and drive shaft described above may form part of the substrate transport mechanism 6 provided inside the loading conveyor section 6A, the positioning conveyor section 6B, and the unloading conveyor section 6C. The driving of the substrate transport mechanism 6 is controlled by a mechanism drive section 54 (described later) of the control section 52.

[0046] As shown in FIG. 3, two transmission sensors 65A (an example of a detection unit) are provided on the input conveyor 6A. Each transmission sensor 65A is an optical sensor paired with a light emitter and a light receiver. Specifically, the transmission sensor 65A includes a light emitter with a built-in light source that emits light as a detection medium, and a light receiver with a built-in light receiving element that receives the light emitted by the light emitter and converts it into an electrical signal. These sensors are arranged facing each other near the pair of conveyor belts 61. The light emitted from the light emitter is projected, for example, in a straight line onto the light entrance window of the light receiver. The detection range of this light is the area between the light emitter and light receiver. When an object (e.g., a circuit board 2) passing between the light emitter and light receiver blocks the projected light, reducing the amount of light incident on the light receiver, the electrical characteristics of the photoelectric conversion element (light receiving element) built into the light receiver change. The transmission sensor 65A detects and amplifies this change in electrical characteristics to obtain an object detection signal (for example, a detection signal for the substrate 2). Note that in Fig. 3 and other figures, only the light-emitter of the transmission sensor is shown, and the light-receiver is not shown.

[0047] One of the two transmission sensors 65A is disposed at the upstream end along the conveying direction on one side of the pair of conveyor belts 61. The other of the two transmission sensors 65A is disposed at the downstream end. Each of these two transmission sensors 65A is disposed so that its light emitter and light receiver sandwich the conveyed board 2 in the Y and Z directions, and detects the conveying state of the board 2 at its position. More specifically, each transmission sensor 65A detects the start of the passage of the board 2 (i.e., the switch from no board detection (sensor ON) to board detection (sensor OFF)) by detecting the downstream edge of the board 2 at its position. Then, each transmission sensor 65A detects the completion of the passage of the board 2 (i.e., the switch from board detection (sensor OFF) to board detection (sensor ON)) by detecting the upstream edge of the board 2. The transmission sensor 65A also detects the detection together with the time, and transmits the detection result together with the detection time (i.e., the time when the board 2 starts passing and the time when the board 2 completes passing) to the control unit 52 (see below) of the printing device 1. At least a part of the detection result and the detection time can be used for predetermined calculations.

[0048] Similarly, the discharge conveyor section 6C is also provided with two transmission sensors 65C (an example of a detection section), one of which is disposed at the upstream end of one of the pair of conveyor belts 61, and the other at the downstream end. These two transmission sensors 65C similarly detect the start of passage of the board 2 by detecting the downstream edge of the board 2 at their respective positions on the discharge conveyor section 6C, and detect the completion of passage of the board 2 by detecting the upstream edge of the board 2, and also detect the times of these detections (i.e., the time the board 2 starts passing and the time it completes passing). At least a portion of the detection results and detection times can be used for predetermined calculations.

[0049] The carry-in conveyor 6A and the carry-out conveyor 6C employ transmission-type sensors 65A and 65C as an example of a detection unit, but the present disclosure is not limited to this. For example, a reflection-type sensor 65B may be used as in the positioning conveyor 6B, and the present disclosure is not limited to this.

[0050] One reflective sensor 65B (an example of a detection unit) is disposed on the positioning conveyor unit 6B. The reflective sensor 65B is configured with a light source and a light receiver housed in a single housing. The reflective sensor 65B detects the transport state of the substrate 2 when light emitted from the light source is reflected by the surface of the substrate 2 and the reflected light enters the light receiver. Similarly, the reflective sensor 65B detects the start of the passage of the substrate 2 by detecting the downstream edge of the substrate 2 at its location, and detects the completion of the passage of the substrate 2 by detecting the upstream edge of the substrate 2, and also detects these times (i.e., the time the substrate 2 starts passing and the time it completes passing). At least a portion of the detection results and detection times can be used for predetermined calculations.

[0051] In this embodiment, the detection unit is not limited to the transmission type sensors 65A, 65C or the reflection type sensor 65B using light, and for example, a magnetic sensor or the like can also be used as appropriate.

[0052] [Control system configuration and the control unit's determination of the transport status] The configuration of the control system of the printing device 1 and the determination of the transport state by its control unit 52 will be described with reference to Figures 4 and 5. Figure 4 is a block diagram illustrating an example of the configuration of the control system of the printing device 1 in Figure 1. Figure 5 is a diagram illustrating an example of the allowable range for determining the transport state.

[0053] As shown in Fig. 4, the printer 1 has a built-in control unit 52 as its central control management unit. The control unit 52 is configured, for example, as a minicomputer, and includes, as hardware, a CPU (Central Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory), an interface circuit, a communication circuit, and a bus connecting these circuits to each other. In the control unit 52, programs stored and held as software in the ROM, RAM, etc. are executed by the CPU, etc., to realize various functions.

[0054] The control unit 52 includes, as its functions, a storage unit 53, a mechanism driving unit 54, a recognition processing unit 55, and a transport state determining unit 56 (an example of a determining unit).

[0055] The control unit 52 is also connected to the substrate holding table moving mechanism 5, the print head 14, the print head moving mechanism 15, the camera unit 26, the camera unit moving mechanism 34, the cleaning unit 27, the cleaning unit moving base 35, the cleaning unit moving mechanism 36, the blade cleaning unit 50, the blade cleaning unit moving mechanism 51, the substrate transport mechanism 6, etc., and controls these mechanisms. The control unit 52 is also connected to a display unit 57. The display unit 57 is a liquid crystal display device, an organic EL device, or the like, and is configured to be able to notify the determination result of the transport state determination unit 56 of the control unit 52 to an external device, for example, an operator.

[0056] The memory unit 53 stores and holds printing operation data necessary for screen-printing the solder paste P on the substrate 2, cleaning operation data necessary for cleaning the lower surface 13c of the screen mask 13, blade cleaning operation data necessary for cleaning the blade 42, etc. The memory unit 53 also stores and holds conveyance speed data SV necessary for the substrate conveyance mechanism 6 to convey the substrate 2 at a predetermined speed, and thresholds TH(+) and TH(-) necessary for the conveyance status determination unit 56 to determine the status of the conveyance belt 61. The conveyance speed data SV may be a rewritable value, and is a setting value appropriately set by an operator via the operation unit of the printing device 1 in accordance with, for example, a production plan for the substrate 2. The threshold TH(+) is a positive threshold, and the threshold TH(-) is a negative threshold. The threshold TH may be, for example, a value equivalent to 10% of the conveyance time corresponding to a measured value or a theoretical value.

[0057] The recognition processing unit 55 performs a recognition process on the image captured by the camera 26c. The image reflects the substrate 2, the screen mask 13, etc. The recognition processing unit 55 detects the positions of the substrate 2 and the screen mask 13 by performing a recognition process on the image. The detection result is used, for example, to align the screen mask 13 with the substrate 2. Furthermore, the recognition processing unit 55 recognizes the state of the lower surface 13c of the screen mask 13 (for example, how much solder paste P remains, and whether mask cleaning was performed properly) by performing a recognition process on the image.

[0058] The mechanism drive unit 54 drives and controls the substrate holding table moving mechanism 5, print head 14, print head moving mechanism 15, camera unit 26, camera unit moving mechanism 34, etc. Through this drive control, the printing apparatus 1 performs the printing operation of screen printing. The mechanism drive unit 54 also drives and controls the cleaning unit 27, cleaning unit moving base 35, cleaning unit moving mechanism 36, etc. Through this drive control, the printing apparatus 1 performs mask cleaning. The mechanism drive unit 54 also drives and controls the blade cleaning unit 50, blade cleaning unit moving mechanism 51, etc. Through this drive control, the printing apparatus 1 performs cleaning of the blade 42 used for mask cleaning (blade cleaning).

[0059] The mechanism driver 54 also reads the conveying speed data SV from the memory 53 and drives and controls the board conveying mechanism 6 in accordance with the conveying speed data SV. This drive control causes the printing device 1 to convey boards at predetermined conveying speeds on the loading conveyor 6A, positioning conveyor 6B, and unloading conveyor 6C. The conveying speed data SV from the memory 53 are set values ​​for the conveying speeds on the loading conveyor 6A, positioning conveyor 6B, and unloading conveyor 6C, and may differ from the actual conveying speed. For example, the actual conveying speed may be slower than the conveying speed data SV due to slack in the conveying belt 61 caused by aging, or it may be faster than the conveying speed data SV due to solder paste P adhering to the conveying belt 61 and causing the board 2 to slip on the conveying belt 61. Therefore, the actual transport time may be slower than the normal time (hereinafter also referred to as the "theoretical value" (theoretical value TV), see below) due to loosening of the transport belt 61 caused by aging, or may be faster than the theoretical value TV due to solder paste P adhering to the transport belt 61 and causing the substrate 2 to slide on the transport belt 61.

[0060] Therefore, the conveying status determination unit 56 calculates the actual value (hereinafter also referred to as the "measured value" (measured value MV)) regarding the conveying time based on the detection results of the transmission type sensors 65A, 65C or the reflection type sensor 65B of each of the input conveyor unit 6A, the positioning conveyor unit 6B and the output conveyor unit 6C.

[0061] Based on the calculation results, the transport state determination unit 56 compares the theoretical value TV and the measured value MV relating to the transport time on each of the carry-in conveyor 6A, the positioning conveyor 6B, and the carry-out conveyor 6C. Based on the comparison results, the transport state determination unit 56 determines the state of the transport belt 61. That is, based on the detection results of the transmission sensors 65A, 65C and the reflective sensor 65B, the transport state determination unit 56 measures the time required for the transport belt 61 to be transported a predetermined distance by the carry-out conveyor 6C, the positioning conveyor 6B, or the carry-out conveyor 6C, and determines the state of the transport belt 61 based on the measured time (measured value MV).

[0062] Then, for example, when the measured value MV is determined to be slow (long) compared with the theoretical value TV in terms of the transport time, the transport state determination unit 56 determines that the transport belt 61 is deteriorated. On the other hand, when the measured value MV is determined to be fast (shorter) compared with the theoretical value TV, the transport state determination unit 56 determines that solder paste P (an example of foreign matter) is attached to the transport belt 61.

[0063] Specifically, when comparing the measured value MV [seconds] with the theoretical value TV [seconds], the conveying status determination unit 56 may calculate the relative error RE [%] using the following equation (1) for each of the input conveyor unit 6A, the positioning conveyor unit 6B, and the output conveyor unit 6C, and determine the conveying status. RE={(MV-TV) / TV}×100 ··· (1)

[0064] Furthermore, the transport state determination unit 56 compares the calculated relative error RE [%] with the threshold values ​​TH(+) and TH(-) in the storage unit 53, as shown in FIG.

[0065] For example, if the measured value MV [seconds] is slower than the theoretical value TV [seconds], the relative error RE [%] will be a positive value. If the relative error RE [%] is determined to be greater than the positive threshold value TH(+) (see FIG. 5), the transport status determination unit 56 determines that the measured time (measured value MV [seconds]) is greater than the theoretical value TV [seconds] by a predetermined value or more, and finally determines that the transport belt 61 is deteriorated. In other words, the transport status determination unit 56 determines that the transport status is in a transport delay state. The result of this determination is notified to the operator via the display unit 57 of the printing device 1. Upon receiving this notification, the operator can, for example, replace the transport belt 61. On the other hand, if the relative error RE [%] is determined to be smaller than the positive threshold value TH(+), the transport status determination unit 56 determines that the error is within the acceptable range and does not notify of an abnormality.

[0066] For example, if the measured value MV is faster than the theoretical value TV, the relative error RE [%] will be a negative value. If the relative error RE [%] is determined to be smaller than the negative threshold value TH(+) (see FIG. 5), the conveyance status determination unit 56 determines that the measured value MV is smaller than the theoretical value TV by a predetermined value or more and finally determines that solder paste P is adhering to the conveyance belt 61. In other words, the conveyance status determination unit 56 determines that the conveyance status is a conveyance skip state. The result of this determination is notified to the operator via the display unit 57 of the printing device 1. Upon receiving this notification, the operator can, for example, clean the surface of the conveyance belt 61 to remove the solder paste P. On the other hand, if the relative error RE [%] is determined to be larger than the negative threshold value TH(-), the conveyance status determination unit 56 determines that the relative error RE [%] is within the acceptable range and does not notify of an abnormality.

[0067] [Calculation of theoretical and measured values ​​for transport time] Calculation of theoretical values ​​TV and measured values ​​MV for the transfer time at the loading conveyor 6A, positioning conveyor 6B, and unloading conveyor 6C will be described with reference to FIGS. 6 to 8. FIG. 6 is a diagram illustrating an example of calculation of theoretical values ​​TV1 and measured values ​​MV1 for the transfer time at the loading conveyor 6A. FIG. 7 is a diagram illustrating an example of calculation of theoretical values ​​TV2 and measured values ​​MV2 for the transfer time at the positioning conveyor 6B. FIG. 8 is a diagram illustrating an example of calculation of theoretical values ​​TV3 and measured values ​​MV3 for the transfer time at the unloading conveyor 6C. The numbers "1," "2," and "3" added to the right of the symbols "SV," "TV," "MV," and "RE" respectively correspond to the loading conveyor 6A, positioning conveyor 6B, and unloading conveyor 6C.

[0068] As shown in FIG. 6, in the loading conveyor section 6A, as described above, two transmissive sensors 65A are arranged at the upstream end (the left end in FIG. 6) and the downstream end (the right end in FIG. 6) along the conveyance direction of the substrate 2. That is, the separation distance L1 [mm] between the transmissive sensor 65A at the upstream end and the transmissive sensor 65A at the downstream end is constant (fixed), and this separation distance L1 is set as the measurement target (measurement range). The separation distance L1 is a known number and may be stored in the storage unit 53, for example. The conveyance state determination unit 56 may calculate the theoretical value TV1 [seconds] in the loading conveyor section 6A based on, for example, this separation distance L1 and the conveyance speed data SV1 [mm / second] of the storage unit 53 by the following formula (2). TV1 = L1 / SV1 ··· (2)

[0069] Regarding the measured value MV1 in the loading conveyor section 6A, the transmissive sensor 65A at the upstream end detects the time T1 [seconds] when the substrate 2 has passed through the arrangement point. Further, the substrate 2 is conveyed, and the transmissive sensor 65A at the downstream end detects the time T2 [seconds] when the substrate 2 has passed through the arrangement point. The conveyance state determination unit 56 may calculate the measured value MV1 [seconds] in the loading conveyor section 6A based on, for example, these times T1 and T2 by the following formula (3). MV1 = T2 - T1 ··· (3)

[0070] The conveyance state determination unit 56 calculates the relative error RE1 [%] based on the calculated theoretical value TV1 and measured value MV1 in the loading conveyor section 6A. As a result of the calculation, when the relative error RE1 [%] exceeds the threshold values TH(+), TH(-), the conveyance state determination unit 56 determines that the conveyor belt 61 of the loading conveyor section 6A is deteriorated (there is a conveyance delay), or that the solder paste P adheres to the conveyor belt 61 of the loading conveyor section 6A (there is a conveyance jump). Specifically, when RE1 > TH(+), the conveyance state determination unit 56 determines that there is a conveyance delay; when RE1 < TH(-), it determines that there is a conveyance jump; and when TH(-) ≤ RE1 ≤ TH(+), it determines that it is within the allowable range.

[0071] As shown in FIG. 7, in the positioning conveyor 6B, one reflective sensor 65B is disposed in the center along the conveyance direction of the substrate 2, as described above. Therefore, the conveyance status determination unit 56 sets the measurement range to the distance L2 between the downstream edge of the substrate 2 when the substrate 2 has passed the transmission sensor 65A at the downstream end of the carry-in conveyor 6A and the position of the reflective sensor 65B, and calculates the theoretical value TV2. The conveyance status determination unit 56 may calculate this distance L2 by subtracting the length LS of the substrate 2 from the distance L3 between the transmission sensor 65A and the reflective sensor 65B on the downstream side of the carry-in conveyor 6A. The length LS of the substrate 2 is a known value and may be stored in the memory unit 53.

[0072] That is, the conveying status determination unit 56 may calculate the theoretical value TV2 [seconds] at the positioning conveyor unit 6B using the conveyance of the upstream edge of the substrate 2 as a reference, for example, based on the separation distance L3, the length LS of the substrate 2, and the conveying speed data SV2 [mm / second] in the memory unit 53, using the following formula (4). TV2=(L3-LS) / SV2 (4)

[0073] For the measurement value MV2 at the positioning conveyor 6B, the transmission sensor 65A at the downstream end of the carry-in conveyor 6A detects the time T2 (seconds) when the board 2 has completed passing through the placement point. The board 2 is further transported, and the reflective sensor 65B detects the time T3 (seconds) when the board 2 begins to pass through the placement point. The transport status determination unit 56 may calculate the measurement value MV2 (seconds) at the positioning conveyor 6B based on these times T2 and T3, for example, using the following formula (5): MV2=T3-T2 (5)

[0074] The conveyance state determination unit 56 calculates a relative error RE2 [%] based on the calculated theoretical value TV2 and measured value MV2 in the positioning conveyor unit 6B. Similar to the above, the conveyance state determination unit 56 determines the state of the conveyor belt 61 in the positioning conveyor unit 6B based on the relative error RE2. That is, as a result of the calculation of the relative error RE2, when the relative error RE2 [%] exceeds the threshold values TH(+), TH(-), the conveyance state determination unit 56 determines that the conveyor belt 61 of the positioning conveyor unit 6B is deteriorated (there is a conveyance delay), or that the solder paste P adheres to the conveyor belt 61 of the positioning conveyor unit 6B (there is a conveyance jump). Specifically, when RE2 > TH(+), the conveyance state determination unit 56 determines that there is a conveyance delay; when RE2 < TH(-), it determines that there is a conveyance jump; and when TH(-) ≤ RE2 ≤ TH(+), it determines that it is within the allowable range.

[0075] As shown in FIG. 8, in the unloading conveyor unit 6C as well, the determination of the conveyance state is executed in the same manner as in the loading conveyor unit 6A. That is, in the unloading conveyor unit 6C, the separation distance L4 [mm] between the transmissive sensor 65C at the upstream end and the transmissive sensor 65C at the downstream end is set within the measurement range. The separation distance L4 is a known number and may be stored in the storage unit 53, for example. The conveyance state determination unit 56 may calculate the theoretical value TV3 [seconds] in the unloading conveyor unit 6C by the following formula (6) based on, for example, this separation distance L4 and the conveyance speed data SV3 [mm / second] in the storage unit 53. TV3 = L4 / SV3 ··· (6)

[0076] Regarding the measured value MV3 in the unloading conveyor unit 6C, the transmissive sensor 65C at the upstream end detects the time T4 [seconds] when the substrate 2 has passed through the arrangement point. Further, as the substrate 2 is conveyed, the transmissive sensor 65C at the downstream end detects the time T5 [seconds] when the substrate 2 has passed through the arrangement point. The conveyance state determination unit 56 may calculate the measured value MV3 [seconds] in the unloading conveyor unit 6C by the following formula (7) based on, for example, these times T4, T5. MV3 = T5 - T4 ··· (7)

[0077] The conveyance state determination unit 56 calculates the relative error RE3 [%] based on the calculated theoretical value TV3 and measured value MV3 at the carry-out conveyor unit 6C. Similar to the above, the conveyance state determination unit 56 determines the state of the conveyor belt 61 at the carry-out conveyor unit 6C based on the relative error RE3. That is, as a result of the calculation of the relative error RE3, when the relative error RE3 [%] exceeds the threshold values TH(+), TH(-), the conveyance state determination unit 56 determines that the conveyor belt 61 of the carry-out conveyor unit 6C is deteriorated (there is a conveyance delay), or that the solder paste P adheres to the conveyor belt 61 of the carry-out conveyor unit 6C (there is a conveyance jump). Specifically, when RE3 > TH(+), the conveyance state determination unit 56 determines that there is a conveyance delay; when RE3 < TH(-), it determines that there is a conveyance jump; and when TH(-) ≤ RE3 ≤ TH(+), it determines that it is within the allowable range.

[0078] Note that the conveyance state determination unit 56 may determine the conveyance state for each of the three conveyor units (for example, the carry-in conveyor unit 6A, the positioning conveyor unit 6B, and the carry-out conveyor unit), or may determine the conveyance state for the entire three conveyors (that is, the entire substrate conveyance mechanism 6).

[0079] As described above, the printing apparatus 1 of the present embodiment has a mechanism for measuring the conveyance time by each conveyor unit of the substrate conveyance mechanism 6. Therefore, the printing apparatus 1 can determine the state of conveyance delay due to deterioration of the conveyor belt 61 and the state of conveyance jump (deceleration brake ineffective) due to the adhesion of the solder paste P to the conveyor belt 61 before it becomes visually confirmable. The conveyance jump can occur, for example, when no friction acts between the rubber of the conveyor unit and the substrate 2. For example, the printing apparatus 1 measures the conveyance time by a substrate detection sensor (for example, transmissive sensors 65A, 65C or reflective sensor 65B) to derive a measured value, and by comparing it with the theoretical value, it can determine whether the actual conveyance time is faster or slower than expected. When the actual conveyance time does not meet a predetermined standard with respect to the theoretical value, the printing apparatus 1 determines that there is a problem with the conveyor belt 61 regardless of whether the actual conveyance time is faster or slower than expected, and for example, it is possible to stop the printing apparatus 1 and perform an operation to prompt cleaning.

[0080] Furthermore, the printing device 1 can identify the cause of the malfunction of the conveyor belt 61 depending on whether the value of the relative error RE is positive or negative. Furthermore, the printing device 1 can determine the conveyance state each time the substrate 2 is conveyed, that is, in real time while the substrate 2 is actually being conveyed.

[0081] Also, for example, an error may occur if the substrate 2 does not arrive at a predetermined position even after a predetermined time has elapsed since the printer 1 started transporting the substrate 2. Before this error occurs, the printer 1 can, for example, detect that the arrival of the substrate 2 is early or late, even though this is not an error, and notify the operator to prompt maintenance.

[0082] The transport status determination unit 56 derives the measured transport time value MV based on the completion of the passage of the board 2 at the loading conveyor unit 6A and the unloading conveyor unit 6C by detecting the upstream edge of the board 2. This allows the printing device 1 to be less affected by the upstream side before being loaded into each conveyor unit, improving the accuracy of calculation of the transport time and also improving the accuracy of determining the transport status of the transport belt 61 based on the transport time.

[0083] As described above, the printing apparatus 1 of this embodiment prints solder paste P on the substrate 2 using a screen mask 13 (an example of a mask) in which predetermined pattern holes 13h (an example of an opening) are formed. The printing apparatus 1 includes a substrate holding table 4 (an example of a substrate holding unit) that holds the substrate 2 and aligns it with the pattern holes 13h, and a print head 14 that fills the pattern holes 13h with solder paste P and prints the solder paste P on the substrate 2. The printing apparatus 1 includes a substrate transport mechanism 6 (an example of a transport unit) that transports the substrate 2 placed on a transport belt 61 (an example of a belt) to the substrate holding table 4 and transports the substrate 2 downstream after printing is complete. The printing apparatus 1 includes a detection unit (e.g., transmission sensors 65A, 65C or reflective sensor 65B) that detects the substrate 2 transported by the substrate transport mechanism 6. The printing device 1 is equipped with a transport state determination unit 56 (an example of a determination unit) that measures the time it takes for the substrate 2 to be transported by the substrate transport mechanism 6 by a predetermined separation distance L (e.g., separation distance L1, L2, or L4) based on the detection result of the detection unit, and determines the state of the transport belt 61 based on the measured time (e.g., measurement value MV (e.g., measurement value MV1, MV2, MV3)).

[0084] As a result, the printing device 1 detects the board 2 being transported by the board transport mechanism 6, measures the time it takes for the board 2 to be transported by the board transport mechanism 6 based on the detection results, and determines whether the measured time is faster or slower than normal during operation, thereby determining the condition of the transport belt 61 in real time. For example, if the transport time is slower than normal (standard), it can be determined that the transport belt 61 is likely to be deteriorated and loose. Also, if the transport time is faster than normal, it can be determined that solder paste P is attached to the transport belt 61 and that the board 2 is likely to get caught on the solder paste P and fly downstream in the transport direction. In this way, the printing device 1 can inspect the condition of the transport belt 61 in real time and predict when to replace or clean the transport belt 61, improving maintenance management and preventing a decrease in the operating rate of the printing process.

[0085] In addition, the transport status determination unit 56 may calculate a theoretical value TV of the transport time (e.g., theoretical value TV1, TV2, or TV3) based on a predetermined separation distance L and the speed at which the substrate transport mechanism 6 transports the substrate 2 (e.g., transport speed data SV1, SV2, or SV3), and determine the status of the transport belt 61 based on the theoretical value TV and the measured value MV.

[0086] That is, the conveyance state determination unit 56 may calculate a theoretical value TV of the conveyance time, which serves as the determination criterion, based on the separation distance L and the conveyance speed data SV, and compare the criterion with the actually measured conveyance time, i.e., the measured value MV, to determine the state of the conveyance belt 61. This allows the printing device 1 to determine the state of the conveyance belt 61 more clearly and uniformly.

[0087] Furthermore, the transport state determining unit 56 may determine that the transport belt 61 is deteriorated when the measured value MV is greater than the theoretical value TV by a predetermined value or more.

[0088] Therefore, by comparing the theoretical value TV with the measured value MV, the printing device 1 can more accurately grasp the condition of the conveyor belt 61. Furthermore, the printing device 1 sets the range in which deterioration of the conveyor belt 61 is unacceptable using threshold values ​​TH(+) and TH(-), and by making judgments based on these threshold values ​​TH(+) and TH(-), it is possible to detect the appropriate time to replace the conveyor belt 61, thereby eliminating unnecessary replacement work of the conveyor belt 61 and suppressing a decrease in the operating rate.

[0089] Furthermore, the transport state determination unit 56 may determine that the solder paste P is attached to the transport belt 61 when the measured value MV is smaller than the theoretical value TV by a predetermined value or more.

[0090] Therefore, by comparing the theoretical value TV with the measured value MV, the printing device 1 can more accurately grasp the state of the conveyor belt 61. Furthermore, the printing device 1 sets the range in which adhesion of solder paste P to the conveyor belt 61 is unacceptable using threshold values ​​TH(+) and TH(-), and by making judgments based on these threshold values ​​TH(+) and TH(-), it is possible to detect the appropriate time to clean the conveyor belt 61, eliminate unnecessary cleaning work of the conveyor belt 61, and suppress a decrease in the operating rate.

[0091] The printing device 1 may also include a display unit 57 that displays information about the state of the conveyor belt 61 determined by the conveyance state determination unit 56. This allows the printing device 1 to, for example, notify an operator of the state of the conveyor belt 61 and prompt the operator to replace or clean the conveyor belt 61.

[0092] Furthermore, in the printing device 1, the substrate transport mechanism 6 may include an input conveyor 6A (an example of a first conveyor) that transports the substrate 2 into the printing device 1, a positioning conveyor 6B (an example of a second conveyor) that transports the substrate 2 to the substrate holding table 4, and an output conveyor 6C (an example of a third conveyor) that transports the substrate 2 after printing has been completed out of the printing device 1. The transport status determination unit 56 may determine the status of the transport belt 61 for each of the input conveyor 6A, the positioning conveyor 6B, and the output conveyor 6C.

[0093] As a result, even if the substrate conveying mechanism 6 is configured to include multiple conveying sections, the printing device 1 can determine the condition of the conveying belt 61 individually for each of the conveying sections, thereby more accurately identifying the areas where the conveying belt 61 needs to be replaced or cleaned.

[0094] Although the embodiments have been described above with reference to the drawings, it goes without saying that the present disclosure is not limited to such examples. It is clear that a person skilled in the art can conceive of various modifications, alterations, substitutions, additions, deletions, and equivalents within the scope of the claims, and it is understood that these also naturally fall within the technical scope of the present disclosure. Furthermore, the components in the above-described embodiments may be combined in any manner as long as they do not deviate from the spirit of the invention. [Industrial Applicability]

[0095] The present disclosure is useful for a printing apparatus, a printing method, and the like that can improve the maintainability of a conveyor belt and suppress a decrease in the operating rate of a printing process. [Explanation of symbols]

[0096] 1 Printing device 2 boards 4. Board holding table 5 Substrate holding table movement mechanism 6. Substrate transport mechanism 6A Intake conveyor section 6B Positioning conveyor section 6C Unloading conveyor section 13 Screen Mask 13a Mask frame 13c Bottom side 13h pattern hole 14 print head 15 Print head movement mechanism 16 Squeegee 26 Camera Unit 26c camera 26p Prism 27 Cleaning unit 34 Camera unit movement mechanism 35 Cleaning unit moving base 36 Cleaning unit moving mechanism 38 Blade holder 42 Blades 50 blade cleaning unit 51 Blade cleaning unit moving mechanism 52 Control section 53 Memory section 54 Mechanism drive unit 55 Recognition processing section 56 Transport status determination unit 57 Display section 61 Conveyor belt 62 driven pulley 63 Drive pulley 64 Possession Shots 65A through-beam sensor 65B Reflective Sensor 65C Through-beam Sensor A1 Lower Area A2 Waiting Area L1 separation distance L2 separation distance L3 separation distance L4 separation distance P solder paste TH threshold θ Rotation direction

Claims

1. A printing device that prints solder paste on a substrate using a mask in which predetermined openings are formed, a substrate holder that holds the substrate and aligns it with the opening; a print head that fills the opening with the solder paste and prints the solder paste on the substrate; a conveying unit that conveys the substrate placed on the belt to the substrate holding unit and conveys the substrate downstream after printing is completed; a detection unit that detects the substrate transported by the transport unit; a determination unit that measures the time it takes for the substrate to be transported a predetermined distance by the transport unit based on the detection result of the detection unit, and determines the state of the belt based on the measured time; A printing device comprising:

2. The determination unit calculating a theoretical value of a transport time based on the predetermined distance and a speed at which the transport unit transports the substrate; determining the state of the belt based on the theoretical value and the measured time; The printing device of claim 1 .

3. The determination unit determines that the belt is deteriorated when the measured time is greater than the theoretical value by a predetermined value or more. The printing device according to claim 2 .

4. the determining unit determines that the solder paste is attached to the belt when the measured time is shorter than the theoretical value by a predetermined value or more. The printing device according to claim 2 .

5. a display unit that displays information about the state of the belt determined by the determination unit; The printing device according to any one of claims 1 to 4.

6. the transport unit includes a first conveyor that transports the substrate into the printing device, a second conveyor that transports the substrate to the substrate holding unit, and a third conveyor that transports the substrate, after printing, out of the printing device; the determination unit determines the state of the belt for each of the first conveyor, the second conveyor, and the third conveyor. The printing device according to any one of claims 1 to 4.

7. A printing method for printing solder paste on a substrate using a mask having predetermined openings, comprising: a substrate holding step of holding the substrate using a substrate holder and aligning the substrate with the opening; a printing step of printing the solder paste onto the substrate by filling the openings with the solder paste; a conveying step of conveying the substrate placed on the belt to the substrate holding unit and conveying the substrate downstream after printing is completed; a detecting step of detecting the substrate transported in the transporting step; a determining step of measuring a time required for the substrate to be transported a predetermined distance in the transporting step based on a detection result in the detecting step, and determining a state of the belt based on the measured time; A printing method comprising:

Images