Suction detecting device and suction detecting method

Abstract

This suction detecting device detects a suction state of a component being suctioned by a suction nozzle that mounts the component on a substrate. This suction detecting device comprises: a light source; a slit that transmits light from the light source; a light-receiving element that receives transmitted light transmitted through the slit; and a processor that detects the suction state on the basis of a change in received light amount of the transmitted light at the light-receiving element before and after a suctioned component crosses the optical path between the light source and the slit. The received light amount at the light-receiving element at a point in time before the component suctioned by the suction nozzle crosses the optical path gradually decreases from the upper side near the suction nozzle toward the lower side far from the suction nozzle.

Description

Suction detection device and suction detection method

[0001] The present disclosure relates to an adsorption detection device and an adsorption detection method.

[0002] Patent Document 1 discloses a component mounting device that determines the suction state of an electronic component that has been supplied to a component supply position and picked up by the tip of a suction nozzle. The component mounting device detects changes in blocking of a passing area through which the suction nozzle passes as it moves up and down, where the blocking or unblocking of the passing area occurs as the suction nozzle moves up and down, calculates the suction state of the electronic component relative to the suction nozzle based on the change in blocking of the passing area, and determines that the suction state of the electronic component is an error if the suction state of the electronic component does not correspond to a normal suction state.

[0003] Japanese Patent Application Publication No. 2004-319854

[0004] The present disclosure has been devised in consideration of the above-described conventional circumstances, and aims to provide an adsorption detection device and an adsorption detection method that can detect with high accuracy the state in which a component is adsorbed by a suction nozzle regardless of the size of the component.

[0005] The present disclosure provides an adsorption detection device that detects the adsorption state of a component by a suction nozzle that places the component on a board, the adsorption detection device comprising: a light source; a slit that transmits light from the light source; a light receiving element that receives the transmitted light that has passed through the slit; and a processor that detects the adsorption state based on a change in the amount of light received by the light receiving element of the transmitted light before and after the component adsorbed by the suction nozzle crosses the optical path between the light source and the slit.

[0006] The present disclosure also provides an adsorption detection method for detecting the adsorption state of a component by a suction nozzle that mounts the component on a board, the method comprising: receiving, with a light receiving element, transmitted light that has passed through a slit from a light source; and detecting the adsorption state based on a transition in the amount of transmitted light received by the light receiving element before and after the component adsorbed by the suction nozzle crosses the optical path between the light source and the slit.

[0007] According to the present disclosure, it is possible to detect with high accuracy the state in which a component is being sucked onto a suction nozzle regardless of the size of the component.

[0008] FIG. 1 shows an example of the internal configuration of a mounting machine according to the present embodiment. FIG. 2 explains an example of measurement of a suction nozzle by a measurement system. FIG. 3 explains a comparison of the amount of light received when a component is being picked up and when it is not being picked up. (a) A diagram showing an example of a state in which a component is normally picked up, (b) A diagram showing an example of a state in which a component is abnormally picked up, and (c) A diagram showing an example of the type and size of a component. FIG. 4 shows an example of the state as viewed from the x arrow before a component picked up by a suction nozzle crosses the light from the light source, and the corresponding relationship between the cross-sectional intensity distribution in that state and the change over time in the photodiode output value. (a) An x arrow view when a large component picked up normally by a suction nozzle crosses the light from the light source. 1A shows an example of the correspondence between the state of a medium-sized component normally or abnormally picked up by a suction nozzle before it crosses the light from the light source, and the cross-sectional intensity distribution and change over time of the photodiode output value in that state; (b) shows an example of the correspondence between the state of a medium-sized component normally or abnormally picked up by a suction nozzle before it crosses the light from the light source, and the cross-sectional intensity distribution and change over time of the photodiode output value in that state; (c) shows an example of the correspondence between the state of a medium-sized component normally or abnormally picked up by a suction nozzle before it crosses the light from the light source, and the cross-sectional intensity distribution and change over time of the photodiode output value in that state; (d) shows an example of the correspondence between the state of a medium-sized component normally or abnormally picked up by a suction nozzle before it crosses the light from the light source, and the cross-sectional intensity distribution and change over time of the photodiode output value in that state; 1A shows an example of the correspondence relationship between the state viewed from the x arrow before the light from the light source is intersected, and the cross-sectional intensity distribution and the change over time of the photodiode output value in that state, according to the present embodiment; FIG. 1B shows an example of the correspondence relationship between the state viewed from the x arrow before the light from the light source is intersected, and the cross-sectional intensity distribution and the change over time of the photodiode output value in that state, according to the present embodiment; FIG. 1C shows an example of the correspondence relationship between the state viewed from the x arrow before the light from the light source is intersected, and the cross-sectional intensity distribution and the change over time of the photodiode output value in that state, according to the present embodiment; 1) A diagram showing an example of the correspondence relationship between the state of a medium-sized component normally or abnormally picked up by a suction nozzle before the light from the light source crosses, as viewed from the x arrow, and the cross-sectional intensity distribution and change over time in the photodiode output value in this state, according to the present embodiment; (b) A diagram showing an example of the correspondence relationship between the state of a small component normally or abnormally picked up by a suction nozzle before the light from the light source crosses, as viewed from the x arrow, and the cross-sectional intensity distribution and change over time in the photodiode output value in this state, according to the present embodiment; (a) A large component normally or abnormally picked up by a suction nozzle when the light source has varying intensity in the y direction;FIG. 1 is a diagram showing an example of the correspondence relationship between the state of each small component viewed from the x arrow before the light from the light source crosses, and the cross-sectional intensity distribution and the change over time of the photodiode output value in that state; (b) a diagram showing an example of a configuration and arrangement in which the intensity of light is varied in the y direction on the light source side according to the present embodiment; (c) a diagram showing an example of a configuration and arrangement in which the intensity of light is varied in the y direction on the light receiving side according to the present embodiment, and the cross-sectional intensity distribution and the change over time of the photodiode output value in that state; (a) a diagram showing an example of a configuration and arrangement in which the intensity of light is varied in the y direction on the light receiving side according to the present embodiment, and the cross-sectional intensity distribution and the change over time of the photodiode output value in that state; (b) a diagram showing the state viewed from the z arrow in (a) as seen from the light source side; and a diagram showing an example of the change over time of the photodiode output value when the adsorption state of a component is made easier to detect than components of other sizes and the detection sensitivity is increased;

[0009] (Background to the present disclosure) Recently, electronic components (hereinafter simply referred to as "components") have become increasingly miniaturized, requiring mounters to handle the mounting of components of various sizes. Mounters detect whether a component is correctly picked up by a suction nozzle (i.e., the component's posture) based on the component height, including pre-registered tolerances. However, when detecting component pickup using pre-registered component heights, the detection accuracy may be reduced due to the influence of component size. For example, the smaller the component, the smaller the difference in length and width dimensions, requiring more accurate measurements for posture detection.

[0010] Here, referring to FIG. 4, an example of the pickup state and dimensions of a component P depending on its size will be described. FIG. 4(a) is a diagram showing an example of a state in which a component P is normally picked up. FIG. 4(b) is a diagram showing an example of a state in which a component P is abnormally picked up. FIG. 4(c) is a diagram showing an example of the type and size of a component P. FIG. 4(a) shows a normal pickup state in which a component P is normally picked up by the suction nozzle 15. That is, a component P having dimensions of length L, thickness T (<W), and width W (>T) is detected as being normally picked up when the wide top surface parallel to the thickness direction is picked up by the suction nozzle 15. This is because the posture of the component P is stable while the top surface is picked up by the suction nozzle 15.

[0011] In contrast, FIG. 4( b ) shows an abnormal pickup state (standing pickup) in which a component P is picked up abnormally by the suction nozzle 15. That is, a component P having dimensions of length L, thickness T (<W), and width W (>T) is detected as being picked up abnormally when a narrow side surface parallel to the width direction is picked up by the suction nozzle 15. This is because the posture of the component P is unstable while the side surface is being picked up by the suction nozzle 15. As shown in FIG. 4( c ), components P, such as chips, come in a variety of sizes depending on their type. The component “0402” is the smallest “small component” of the components shown in FIG. 4( c ), the component “1005” is the second smallest “medium component” of the components shown in FIG. 4( c ), and the component “2012” is the largest “large component” of the components shown in FIG. 4( c ).

[0012] To make the following explanation easier to understand, the types of parts will be described by referring to the part "2012" in Fig. 4(c) as a "large part," the part "1005" in Fig. 4(c) as a "medium part," and the part "0402" in Fig. 4(c) as a "small part." However, these types of parts are merely described conceptually, and are not limited to three types, and may be two types, "large parts" and "small parts," or may be four or more types.

[0013] Next, with reference to FIGS. 5 to 7 , an example of detecting the state of a component being picked up by the suction nozzle 15 depending on its size will be described. FIG. 5 is a diagram showing an example of the relationship between the state of a component picked up by the suction nozzle 15 as viewed from the x arrow before the component crosses the light from the light source 14A, and the cross-sectional intensity distribution GR1 and the change in the photodiode output value over time GR2 in that state. FIG. 6( a) is a diagram showing an example of the relationship between the state of a large component P1 picked up normally by the suction nozzle 15 as viewed from the x arrow when the large component P1 crosses the light from the light source 14A, and the cross-sectional intensity distribution GR1a and the change in the photodiode output value over time GR2a in that state. FIG. 6( b) is a diagram showing an example of the relationship between the state of a large component P1 picked up normally or abnormally by the suction nozzle 15 as viewed from the x arrow before the large component P1 crosses the light from the light source 14A, and the cross-sectional intensity distribution GR1b and the change in the photodiode output value over time GR2b in that state. 7A is a diagram showing an example of the correspondence relationship between the state as viewed by the x arrow before a medium component P2 normally or abnormally picked up by the suction nozzle 15 crosses the light from the light source 14A, and the cross-sectional intensity distribution GR1c and the change over time GR2c of the photodiode output value in that state. FIG. 7B is a diagram showing an example of the correspondence relationship between the state as viewed by the x arrow before a small component P3 normally or abnormally picked up by the suction nozzle 15 crosses the light from the light source 14A, and the cross-sectional intensity distribution GR1d and the change over time GR2d of the photodiode output value in that state.

[0014] FIG. 5 shows how light from light source 14A is received by photodiode 14D through slit 14C. In this state, component P is not shown because the component picked up by suction nozzle 15 has not yet crossed the path of light from light source 14A. In other words, component P has not yet crossed the path of light from light source 14A, and photodiode 14D receives light that has passed through slit 14C without the light from light source 14A being blocked by component P. Therefore, cross-sectional intensity distribution GR1 shows that light is received uniformly by photodiode 14D regardless of the position of the slit hole in slit 14C. Furthermore, the time-dependent change in photodiode output value GR2 indicates a constant reference value (P0). In the following description, the output value of photodiode 14D when there is no obstruction, such as a component, is defined as P0.

[0015] 6A shows a state in which the light from light source 14A is blocked by large component P1 when large component P1 held by suction nozzle 15 crosses the light from light source 14A. Therefore, the light is less likely to be received by photodiode 14D at the position of the slit where large component P1 blocks the light, and the cross-sectional intensity at the position of the slit where large component P1 blocks the light is significantly lower than that shown in cross-sectional intensity distribution GR1a (see cross-sectional intensity distribution GR1a). Furthermore, the change in photodiode output value over time GR2a shows that the output value drops from the start to the end of the large component P1 held by suction nozzle 15 crossing the light.

[0016] However, when a large component P1 is abnormally attracted to the suction nozzle 15 (see FIG. 4B), as shown in FIG. 6B, the position (range) of the slit that blocks the light from the light source 14A when the large component P1 crosses the light becomes wider in the vertical direction (see the y direction in FIG. 1) (see the dashed line). Specifically, the amount of light received by the photodiode 14D is reduced by the height difference (e.g., equivalent to (W-T)) required for discrimination based on the large component P1. In other words, the cross-sectional intensity at the position of the slit where the abnormally attracted large component P1 blocks the light is lower than that in the cross-sectional intensity distribution GR1a (see the cross-sectional intensity distribution GR1b). Furthermore, the time-dependent change in the photodiode output value GR2b indicates a greater drop in the output value from the start to the end of the crossing of the light by the large component P1 that is abnormally attracted to the suction nozzle 15 compared to the time-dependent change in the photodiode output value GR2a.

[0017] As shown in FIG. 7A, when a medium component P2 is abnormally attracted to the suction nozzle 15 (see FIG. 4B), the position (area) of the slit that blocks the light from the light source 14A when the medium component P2 crosses the light is narrower in the vertical direction (see the y direction in FIG. 1) than when the large component P1 crosses (see the dashed line). Specifically, the amount of light received by the photodiode 14D is reduced by the height difference (e.g., equivalent to (W-T)) required for discrimination of the medium component P2, similar to that of the large component P1. In other words, the cross-sectional intensity at the position of the slit where the abnormally attracted medium component P2 blocks the light is lower than when the medium component P2 is normally attracted (see the cross-sectional intensity distribution GR1c). Furthermore, the time-dependent change in the photodiode output value GR2c indicates that the output value drops more from the start to the end of the crossing of the light when the medium component P2 is abnormally attracted to the suction nozzle 15 than when the medium component P2 is normally attracted. However, this drop in output value is smaller than the drop in output value of the large component P1.

[0018] As shown in FIG. 7B, when a small component P3 is abnormally attracted to the suction nozzle 15 (see FIG. 4B), the position (range) of the slit that blocks the light from the light source 14A when the small component P3 crosses the light is narrower in the vertical direction (see the y direction in FIG. 1) than when the large component P1 and the medium component P2 cross the light (see the dashed line). Specifically, the amount of light received by the photodiode 14D is lower, similar to that of the large component P1 and the medium component P2, by the height difference (e.g., equivalent to (W-T)) required for discrimination of the small component P3. In other words, the cross-sectional intensity at the position of the slit where the abnormally attracted small component P3 blocks the light is lower than when the small component P3 is normally attracted (see the cross-sectional intensity distribution GR1d). Furthermore, the time-dependent change in the photodiode output value GR2d indicates that the output value drops more from the start to the end of the crossing of the light when the small component P3 is abnormally attracted to the suction nozzle 15 compared to when the small component P3 is normally attracted. However, this drop in output value is smaller than the drop in output value at the middle part P2.

[0019] Based on the explanations of Figures 5 to 7 above, not only does the value of the height difference (W-T) that needs to be determined vary depending on the component size, but the value of (W-T) also decreases as the component size decreases. This presents a problem when simultaneously detecting the pickup status of large and small components. Because the light beam 14B from light source 14A has a generally uniform intensity balance in the vertical direction (see the y direction in Figure 1 ), the smaller the component, the smaller the difference in the amount of received light between normal and abnormal states based on the (W-T) value. This results in a problem: the smaller the component, the less accurate the pickup status detection. For example, the larger the component, the greater the difference in the amount of drop in the photodiode output value, and the smaller the component, the smaller the difference in the amount of drop in the photodiode output value. This presents a problem, particularly with small components, in that it is not easy to accurately detect whether the pickup status is normal or abnormal.

[0020] Therefore, in the following embodiments, an example of a suction detection device and a suction detection method that can detect with high accuracy whether a component is being picked up by a suction nozzle regardless of the size of the component will be described.

[0021] Hereinafter, with reference to the drawings as appropriate, embodiments that specifically disclose the configuration and operation of the adsorption detection device and adsorption detection method according to the present disclosure will be described in detail. However, unnecessary detailed description may be omitted. For example, detailed description of well-known matters or redundant description 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. Note that 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 recited in the claims.

[0022] In this specification, the X, Y, and Z axes are defined as the directions shown in Figure 1. The x and z directions are parallel to the surface direction of the substrate 13 and perpendicular to each other. The y direction is perpendicular to the x and z directions and is the thickness or height direction of the substrate 13. The y direction may also be referred to as the up-down direction. In the accompanying drawings, the same components are given the same reference numerals, and descriptions of the same content will be simplified or omitted, and different content will be described.

[0023] 1. Example of Mounting Machine Configuration First, the internal configuration of a mounting machine 100 according to the first embodiment will be described with reference to FIGS. 1 to 3. The mounting machine 100 is an example of a suction detection device according to the present disclosure. FIG. 1 is a diagram illustrating an example of the internal configuration of the mounting machine 100 according to the present embodiment. FIG. 2 is a diagram illustrating an example of measurement of a suction nozzle using a measurement system. FIG. 3 is a diagram illustrating a comparison of the amount of light received when a component is being picked up and when a component is not being picked up. Note that while FIG. 1 illustrates one mounting machine connected to the management computer 31, multiple mounting machines may be connected simultaneously. In FIG. 1, the x-axis rail 10A, the z-axis rail 10B, the component supply unit 12, and the board rail 16 are not shown.

[0024] The mounting machine 100 drives each of the pair of board rails 16 to transport the board 13 in a predetermined transport direction (e.g., the z direction). The mounting machine 100 drives the mounting head 11, which is equipped with one or more suction nozzles 15, along at least one of the x-axis rail 10A and the z-axis rail 10B, and uses the suction nozzles 15 to pick up components P supplied by the component supply unit 12. After picking up the components P with the suction nozzles 15, the mounting machine 100 moves the mounting head 11 above the board 13 to transport the components P, and then mounts the components P corresponding to each component mounting position on the board 13. The mounting machine 100 mounts all of the components P to be mounted on the board 13 to produce a mounted board, and then drives each of the pair of board rails 16 to transport the produced mounted board in the predetermined transport direction (e.g., the z direction).

[0025] The mounting machine 100 includes at least a mounting head 11, a component supply unit 12, a measurement system 14, one or more suction nozzles 15, a pair of board rails 16, a processor 17, a mounting operation control unit 18, a memory 19, and an output unit 20. Note that the communication unit 21 is not a required component and may be omitted. When the mounting machine 100 is configured to include the communication unit 21, it may be communicably connected to a management computer 31 and be able to send and receive data.

[0026] Each of the pair of x-axis rails 10A is coupled to a z-axis rail 10B and supports the z-axis rail 10B so that it can move freely in the x and -x directions. The z-axis rail 10B is coupled to the mounting head 11 and supports the mounting head 11 so that it can move freely in the z and -z directions. Each of the pair of x-axis rails 10A and the z-axis rail 10B constitute a movement mechanism that moves the mounting head 11.

[0027] The mounting head 11 is controlled by a movement mechanism to move in the x-axis, z-axis, and y-axis directions. The mounting head 11 is coupled to a z-axis rail 10B and transports components P back and forth between the component supply unit 12 and a predetermined component mounting position on the board 13.

[0028] The mounting head 11 is equipped with one or more suction nozzles 15. The suction nozzles 15 are raised and lowered in the y-axis direction (in other words, the up-down or lifting direction) between the transport height of the component P and the mounting height of the component P on the board 13 by the processor 17. The mounting head 11 performs suction and release of suction of the component P by the suction nozzles 15 by the processor 17. The mounting head 11 picks up the component P supplied by the component supply unit 12 with the tip of the suction nozzle 15, transports it to a predetermined component mounting position on the board 13, and then releases the suction state of the component P to mount it at the component mounting position on the board 13.

[0029] Here, after suctioning a component P, the mounting head 11 moves so that the component P picked up at the tip of the suction nozzle 15 passes through a light beam 14B emitted from a light source 14A disposed between the component supply unit 12 and the board 13. This allows the processor 17 of the mounting machine 100 to determine the suction state of the component P picked up by each suction nozzle 15 based on the amount of light blocked by the light beam 14B (i.e., the transition indicating the amount of fluctuation in the amount of light received).

[0030] The component supply unit 12 is controlled by the processor 17 to supply the components P to be mounted on the board 13. The component supply unit 12 may be capable of simultaneously supplying a plurality of different types of components P. The arrangement of the component supply unit 12 shown in FIG. 2 is an example and is not limited to this.

[0031] The measurement system 14 includes a light source 14A, a slit 14C, a photodiode 14D as a photoelectric conversion element, and a current-voltage converter 14E. The slit 14C has a slit hole 141C and is arranged on a surface that is parallel to the z direction and opposite to the light source 14A. The arrangement position of the measurement system 14 shown in FIG. 1 is one example and is not limited thereto. It is sufficient that the measurement system 14 is arranged so that the shape of the tip portion of each suction nozzle 15 provided in the mounting head 11 can be measured one by one.

[0032] The photodiode 14D is an example of a light-receiving element, and receives transmitted light, i.e., light beam 14B, irradiated from a light source 14A such as a light-emitting diode (LED) or a laser diode (LD) and transmitted through or passing through a slit hole 141C of the slit 14C, converts the light into an electrical signal, and outputs the electrical signal to the current-voltage converter 14E. The current-voltage converter 14E converts the electrical signal (current) output from the photodiode 14D into a voltage and outputs the converted value (IV converted value) to the processor 17 (e.g., a determination unit 17A). The current-voltage converter 14E outputs the IV converted value to the determination unit 17A at a predetermined cycle (e.g., a cycle on the order of kHz).

[0033] The slit 14C is positioned so that the slit hole 141C, which is formed in a substantially rectangular shape, is located at a position (height) where the shape of the tip portion of the suction nozzle 15 can be measured. Specifically, the placement height of the slit hole 141C of the slit 14C relative to the suction nozzle 15 is determined based on the thickness of the component P in the y direction and the tip height of the suction nozzle 15 attached to the mounting head 11. Note that the shape of the slit hole 141C is not limited to a substantially rectangular shape. For example, the shape of the slit hole 141C may be elliptical. Note that the tip height of the suction nozzle 15 and the suction height of the component P are the minimum heights of the suction nozzle 15 in the height direction in which the mounting head 11 rises and falls.

[0034] The processor 17 is configured using, for example, a Central Processing Unit (CPU), a Digital Signal Processor (DSP), or a Field Programmable Gate Array (FPGA), and controls the operation of each unit of the mounting machine 100. The processor 17 performs various processes and controls in cooperation with the memory 19. Specifically, the processor 17 references programs and data stored in the memory 19 and executes the programs to realize the functions of each unit. Note that the units referred to here are, for example, the determination unit 17A, but are not intended to be limited to the determination unit 17A.

[0035] The determination unit 17A calculates the position information of each suction nozzle 15 provided to the mounting head 11 based on the speed information and position information of the mounting head 11 output from the mounting operation control unit 18, and acquires the identification of the suction nozzle 15 corresponding to the IV conversion value output from the current-voltage conversion unit 14E and the IV conversion value corresponding to the identified suction nozzle 15. Based on the acquired IV conversion value, the determination unit 17A calculates the value of the tip height of the suction nozzle 15 or the suction height of the component P. Based on the tip height of the suction nozzle 15 when a component is not being picked up and the tip height of the suction nozzle 15 or the suction height of the component P when a component is being picked up, the determination unit 17A performs suction detection to determine whether the suction is normal or abnormal if the component P is being picked up. The determination unit 17A outputs the suction detection result to the mounting operation control unit 18 and the output unit 20.

[0036] The mounting operation control unit 18 controls the mounting operation of the components P executed by the mounting head 11. Specifically, the mounting operation control unit 18 moves the mounting head 11 between the component supply unit 12 and a predetermined component mounting position on the board 13, and executes the suction operation of the components P at the component supply unit 12 by suction control of the suction nozzles 15, and the mounting operation (suction release operation) of the components P at the predetermined component mounting position on the board 13. The mounting operation control unit 18 outputs speed information and position information of the mounting head 11 to the processor 17. Note that the mounting operation control unit 18 may also output position information of each suction nozzle 15 to the processor 17.

[0037] The memory 19 includes, for example, a random access memory (RAM) serving as a work memory used when executing each process of the processor 17, and a read-only memory (ROM) for storing programs and data that define the operation of the processor 17. The RAM temporarily stores data or information generated or acquired by the processor 17. The ROM stores programs that define the operation of the processor 17. The memory 19 stores a reference value 19A, a threshold value 19B, and a threshold value 19C that are used for various determinations (e.g., component suction detection) performed by the determination unit 17A. The memory 19 also stores production data for producing the mounting board to be produced, as well as the number and arrangement information of the suction nozzles 15 provided on the mounting head 11.

[0038] The production data here refers to information used to produce mounting boards by the mounting machine 100. The production data includes, for example, the size of the board 13, the size (thickness) of the component P, the shape of the component P, information about each suction nozzle 15, the number of boards 13 produced, etc. Note that the production data does not need to be limited to the data for the items described above.

[0039] The reference value 19A is the minimum height of the tip of the suction nozzle 15 when no component is being picked up, and is recorded for each suction nozzle 15. The determination unit 17A measures the minimum value of the tip height of the suction nozzle 15 when no component P is being picked up, based on the IV conversion value output from the measurement system 14. The determination unit 17A acquires the measured minimum value of the tip height of the suction nozzle 15 as the reference value 19A of this suction nozzle 15 and stores it in the memory 19.

[0040] The threshold value 19B is set based on the latest reference value 19A for each suction nozzle 15 and a predetermined value α corresponding to the size or thickness of the component P, and the threshold value for determining whether the component P is being picked up by the suction nozzle 15 is recorded for each suction nozzle 15. Specifically, the threshold value 19B is calculated by adding the predetermined value α to the height (reference value 19A) of the suction nozzle 15. The predetermined value α is a value that reduces the IV conversion value corresponding to the height of the suction nozzle 15, and is set to a value that is smaller than the size (thickness) of the component P in the height direction and larger than the magnitude of vibration in the height direction when the mounting head 11 is driven. The predetermined value α may be set to a different value for each component P picked up by the suction nozzle 15.

[0041] The threshold value 19C is a threshold value used to determine whether a component P picked up by each suction nozzle 15 is picked up normally (see FIG. 4A) or abnormally (see FIG. 4B). Specifically, the threshold value 19C has two values: (1) P0 (see FIG. 5), which is the photodiode output value (IV conversion value) at the time before the component P (e.g., large component P1) picked up by the suction nozzle 15 crosses the light beam 14B, and (2) a threshold value for determining whether the same component (e.g., large component P1) is picked up normally or abnormally. The latter "threshold value for determining whether the large component P1 is normally or abnormally attracted" is the difference between the amount of drop from P0 in the photodiode output value when the large component P1 crosses (blocks) the light beam 14B when the large component P1 is normally attracted and the amount of drop from P0 in the photodiode output value when the large component P1 crosses (blocks) the light beam 14B when the large component P1 is abnormally attracted, or a value obtained by multiplying this difference value by a predetermined coefficient (e.g., 0.5 to 0.9). The determination unit 17A detects whether the component (e.g., large component P1) is normally or abnormally attracted based on a comparison of the IV converted value, which is the output of the current-voltage conversion unit 14E, with the threshold value 19C.

[0042] The output unit 20 is configured using a display such as a Liquid Crystal Display (LCD) or an organic electroluminescence (EL) display. The output unit 20 outputs a screen (not shown) or a sound indicating the suction detection result of the component P output from the determination unit 17A.

[0043] The communication unit 21 is connected to the management computer 31 so as to be able to communicate wirelessly or via a wire to send and receive data. The communication unit 21 transmits the suction detection result of the component P output from the determination unit 17A to the management computer 31. The communication unit 21 also acquires production data of the board 13 or production data for each component P transmitted from the management computer 31 and outputs the data to the processor 17. Note that the wireless communication referred to here refers to communication via a wireless local area network (LAN) such as Wi-Fi (registered trademark).

[0044] The component P pickup detection process may be executed by the management computer 31. In such a case, the mounting machine 100 associates the IV conversion value used in the component detection process for the component P with the speed information and position information of the mounting head 11 or suction nozzle 15, and transmits them to the management computer 31. The management computer 31 determines the reference value 19A and the threshold value 19B based on the IV conversion value and the speed information and position information of the mounting head 11 or suction nozzle 15 transmitted from the mounting machine 100, executes the component pickup detection process, and transmits the component pickup detection process results to the mounting machine 100. The mounting machine 100 controls the mounting operation control unit 18 based on the component pickup detection process results, and outputs the component pickup detection process results to the output unit 20.

[0045] The control computer 31 is, for example, a personal computer (PC), a notebook PC, or a tablet terminal, and is operated by an operator. The control computer 31 is communicably connected to one or more mounting machines, and generates production information related to the production process of the mounting board that has been input or set in advance by the operator, as well as execution commands for executing the production process, and transmits these to each mounting machine.

[0046] The management computer 31 may include a processor (not shown) and a memory (not shown), and may execute component suction detection processing for the suction nozzle 15 based on various information or data transmitted from the mounting machine 100. In such a case, the processor (not shown) of the management computer 31 realizes the function of the processor 17 of the mounting machine 100, and the memory (not shown) realizes the function of the memory 19 of the mounting machine 100, and the management computer 31 transmits the component suction detection processing results to the mounting machine 100.

[0047] Here, the IV (current-voltage) conversion process executed by the current-voltage converter 14E will be described with reference to FIG. 3 . For ease of understanding, the mounting head 11 is not shown in FIG. 3 . First, as shown in FIG. 2 , when the suction nozzle 15 of the mounting machine 100 is not yet mounted on a component, the mounting head 11 crosses the light beam 14B of the measurement system 14 (see FIG. 1 ) located midway from the board 13 to the component supply unit 12 along the movement direction of the mounting head 11 when no component is mounted, as shown in FIG. 2 . Then, when the suction nozzle 15 of the mounting machine 100 is mounting a component, the mounting head 11 crosses the light beam 14B of the measurement system 14 (see FIG. 1 ) located midway from the component supply unit 12 to the board 13 along the movement direction of the mounting head 11 when the component is mounted, as shown in FIG. 2 .

[0048] The slit 141C is positioned at a height that allows the light beam 14B to be blocked by the tip of the suction nozzle 15 and the component P sucked onto the tip of the suction nozzle 15. The photodiode 14D outputs a current corresponding to the amount of light (light intensity) of the light beam 14B, which is transmitted light that has passed through or been transmitted through the slit 141C, to the current-voltage converter 14E. The current-voltage converter 14E converts the current output from the photodiode 14D into a voltage value corresponding to the amount of light (light intensity) of the light beam 14B, and outputs the voltage value to the determination unit 17A.

[0049] The vertical axis of each of the IV conversion graphs Op1 and Op2 represents the IV conversion value output from the current-voltage converter 14E. The horizontal axis of each of the IV conversion graphs Op1 and Op2 represents time. The IV conversion values ​​of each of the IV conversion graphs Op1 and Op2 decrease in proportion to the amount of light ray 14B blocked.

[0050] The IV conversion graph Op01 shows the time series change in the IV conversion value (output) when the suction nozzle 15 passes between the light source 14A and the slit 141C when not picking up a component. The minimum value Op01A is the minimum value of the IV conversion value of the IV conversion graph Op01, i.e., the reference value of the suction nozzle 15. However, if the suction nozzle 15 itself does not block the light ray 14B passing through the slit 141C when the tip (lower end) of the suction nozzle 15 passes through the slit 141C, the IV conversion value (output) will be a nearly constant value, as shown in FIG. 5. The reason why the IV conversion graph Op01 in FIG. 3 does not remain constant but decreases is because the suction nozzle 15 itself blocks the light ray 14B passing through the slit 141C during this decrease.

[0051] The IV conversion graph Op02 shows the time series change in the IV conversion value (output) when the suction nozzle 15 passes between the light source 14A and the slit 141C during component suction. The minimum value Op02A is the minimum value of the IV conversion value of the IV conversion graph Op02, i.e., the reference value of the suction nozzle 15. In the IV conversion graph Op02, the IV conversion value is smaller because the amount of light blocked by the light beam 14B increases when the suction nozzle 15 is picking up a component P compared to the amount of light blocked when no component is picking up.

[0052] The determination unit 17A sets a threshold value based on the minimum value Op01A of the IV conversion graph Op01 and a predetermined value α. Specifically, the determination unit 17A sets the IV conversion value obtained by adding the predetermined value α to the minimum value Op01A as the threshold value used for component pickup determination. The determination unit 17A performs component pickup determination for the suction nozzle 15 by comparing the minimum value Op02A of the IV conversion graph Op02 with the threshold value. This allows the determination unit 17A to accurately determine whether a component is being picked up by the suction nozzle 15. Furthermore, the mounter 100 according to this embodiment not only determines whether a component is being picked up by the suction nozzle 15, but also accurately determines whether the component being picked up by the suction nozzle 15 is being picked up normally (see FIG. 4A) or abnormally (see FIG. 4B).

[0053] Next, referring to FIGS. 8 and 9 , a method for determining whether a component picked up by the suction nozzle 15 is normally or abnormally picked up, regardless of the component size, will be described. FIG. 8( a) is a diagram showing an example of the correspondence relationship between the state of the component picked up by the suction nozzle as viewed from the x arrow before the light from the light source crosses, and the cross-sectional intensity distribution and the change over time of the photodiode output value in that state, according to this embodiment. FIG. 8( b) is a diagram showing an example of the correspondence relationship between the state of the large component picked up by the suction nozzle normally or abnormally before the light from the light source crosses, and the cross-sectional intensity distribution and the change over time of the photodiode output value in that state, according to this embodiment. FIG. 9( a) is a diagram showing an example of the correspondence relationship between the state of the medium component picked up by the suction nozzle normally or abnormally before the light from the light source crosses, and the cross-sectional intensity distribution and the change over time of the photodiode output value in that state, according to this embodiment. FIG. 9( b) is a diagram showing an example of the correspondence relationship between the state of the small component picked up by the suction nozzle normally or abnormally before the light from the light source crosses, and the cross-sectional intensity distribution and the change over time of the photodiode output value in that state, according to this embodiment.

[0054] 8A, the intensity distribution of the transmitted light, which is the light beam 14B that has passed through or been transmitted through the slit 141C, is not uniform regardless of the position of the slit 141C, but is biased depending on the position, resulting in an overall non-uniformity. Specifically, the intensity of the light beam 14B from the light source 14A gradually decreases in the vertical direction (see the y direction in FIG. 1).

[0055] 8A shows how light from the light source 14A is received by the photodiode 14D through the slit 14C. When the slit 141C of the slit 14C is positioned at the top (i.e., the side closest to the tip of the suction nozzle 15), the amount of light ray 14B (transmitted light) that passes through or is transmitted through the slit 14C and is received by the photodiode 14D is maximized. When the slit 141C is positioned at the bottom (i.e., the side farthest from the tip of the suction nozzle 15), the amount of light ray 14B (transmitted light) that passes through or is transmitted through the slit 14C and is received by the photodiode 14D is minimized. Furthermore, as the position of the slit 141C moves from top to bottom, the amount of light ray 14B (transmitted light) that passes through or is transmitted through the slit 14C and is received by the photodiode 14D gradually decreases. For this reason, in the cross-sectional intensity distribution GR1e, the intensity of the received light beam 14B is high when the slit hole 141C of the slit 14C is positioned at the top, but the intensity of the received light beam 14B gradually decreases from top to bottom. Although the cross-sectional intensity distribution GR1e has characteristics different from the cross-sectional intensity distribution GR1 of Fig. 5, the change over time GR2e of the photodiode output value has a constant output value, which is the reference value (P0), similar to the change over time GR2 of Fig. 5. This constant output value, which is the reference value (P0), serves as the reference value (see reference value 19A of Fig. 1) for detecting whether the adsorption is normal or abnormal.

[0056] 8(b) shows the cross-sectional intensity distribution GR1f of the received light and the change in the photodiode output value over time GR2f when the large component P1 blocks the light beam 14B from the light source 14A, when the large component P1 is normally and abnormally attracted to the suction nozzle 15. The height (W-T) required for discrimination shown in FIG. 8(b) is the difference between the suction height when the large component P1 is normally attracted and the suction height when the large component P1 is abnormally attracted. In other words, when detecting the suction state of the large component P1 actually attracted by the suction nozzle 15, if the detected height blocking the slit hole 141C is equal to the value of the height (W-T) required for discrimination, abnormal suction is detected. The memory 19 stores, as threshold values ​​19C for the large component P1, a threshold for the amount of drop from the reference value (P0) of the photodiode output value of the received light when the large component P1 blocks the light beam 14B from the light source 14A during normal suction, and a threshold for the amount of drop from the reference value (P0) of the photodiode output value of the received light when the large component P1 blocks the light beam 14B from the light source 14A during abnormal suction. The determination unit 17A detects whether the large component P1 is normally or abnormally suctioned based on a comparison between the large component threshold value 19C and the amount of drop from the reference value (P0) of the photodiode output value of the received light when the large component P1, which is actually measured when it is picked up by the suction nozzle 15, blocks the light beam 14B from the light source 14A. The height (W-T) at which the large component P1 must be distinguished is greater than the heights (W-T) at which the other medium and small components P2 and P3 must be distinguished. For this reason, as explained in FIG. 8( a), the difference in component height at which the light beam 14B is blocked when the large component P1 is normally adsorbed and when it is abnormally adsorbed (i.e., the height (W-T) at which discrimination is required) is relatively low in the overall intensity balance of the light beam 14B from the light source 14A because the position of the slit 141C is located on the lower side. However, since the value of the height (W-T) at which discrimination is required for the large component P1 is sufficiently large compared to the heights (W-T) at which discrimination is required for components of other sizes, it is considered that the difference in the amount of light received by the photodiode 14D is also sufficiently large.Therefore, the judgment unit 17A can accurately determine (detect) whether the large component P1 picked up by the suction nozzle 15 is being picked up normally or abnormally, based on a comparison between the threshold value 19C for large components and the difference in the amount of received light corresponding to the height (WT) at which the large component P1 needs to be judged.

[0057] 9(a) shows the cross-sectional intensity distribution GR1g of the received light and the change in the photodiode output value over time GR2g when the intermediate component P2 blocks the light beam 14B from the light source 14A, when the intermediate component P2 is normally and abnormally sucked by the suction nozzle 15. The height (W-T) required for discrimination shown in FIG. 9(a) is the difference between the suction height when the intermediate component P2 is normally sucked and the suction height when the intermediate component P2 is abnormally sucked. In other words, when detecting the suction state of the intermediate component P2 actually sucked by the suction nozzle 15, if the height at which the slit hole 141C is blocked is detected to be equal to the value of the height (W-T) required for discrimination, abnormal suction is detected. The memory 19 stores, as medium component P2 threshold values ​​19C, a threshold for the amount of drop from the reference value (P0) of the photodiode output value of the received light when the medium component P2 blocks the light beam 14B from the light source 14A during normal suction, and a threshold for the amount of drop from the reference value (P0) of the photodiode output value of the received light when the medium component P2 blocks the light beam 14B from the light source 14A during abnormal suction. The determination unit 17A detects whether the medium component P2 is normally or abnormally suctioned based on a comparison between the medium component threshold value 19C and the amount of drop from the reference value (P0) of the photodiode output value of the received light when the medium component P2, picked up by the suction nozzle 15, actually blocks the light beam 14B from the light source 14A. The height (W-T) at which the medium component P2 must be distinguished is smaller than the height (W-T) at which the large component P1 must be distinguished, but is greater than the height (W-T) at which the small component P3 must be distinguished. For this reason, the difference in component height at which medium component P2 blocks light beam 14B during normal and abnormal suction (i.e., the height at which discrimination is required (W-T)) is stronger in the overall intensity balance of light beam 14B from light source 14A than in the lower portion because slit 141C is located toward the center or above it. In other words, the value of the height at which discrimination is required for medium component P2 (W-T) is smaller than the value of the height at which discrimination is required for large component P1, but because the position in the y direction at which medium component P2 blocks light beam 14B (component height) is toward the center or above slit 141C in the intensity balance of light beam 14B, the amount of light received by photodiode 14D when medium component P2 blocks light beam 14B is expected to be the same as that received by large component P1.Therefore, similar to the case of the large component P1, the judgment unit 17A can accurately judge (detect) whether the medium component P2 picked up by the suction nozzle 15 is being picked up normally or abnormally, based on a comparison between the threshold value 19C for medium components and the difference in the amount of received light corresponding to the required height (WT) of the medium component P2.

[0058] 9(b) shows the cross-sectional intensity distribution GR1h of the received light and the change in the photodiode output value over time GR2h when the small component P3 blocks the light beam 14B from the light source 14A, when the small component P3 is normally and abnormally attracted to the suction nozzle 15. The height (W-T) required for discrimination shown in FIG. 9(b) is the difference between the suction height when the small component P3 is normally attracted and the suction height when the small component P3 is abnormally attracted. In other words, when detecting the suction state of the small component P3 actually attracted by the suction nozzle 15, if the height at which the slit 141C is blocked is detected to be equal to the value of the height (W-T) required for discrimination, abnormal suction is detected. The memory 19 stores, as threshold values ​​19C for small component P3, a threshold for the amount of drop from the reference value (P0) of the photodiode output value of the received light when the small component P3 blocks the light beam 14B from the light source 14A during normal suction, and a threshold for the amount of drop from the reference value (P0) of the photodiode output value of the received light when the small component P3 blocks the light beam 14B from the light source 14A during abnormal suction. The determination unit 17A detects whether the small component P3 is normally or abnormally suctioned based on a comparison between the small component threshold value 19C and the amount of drop from the reference value (P0) of the photodiode output value of the received light when the small component P3, which is actually measured when it is picked up by the suction nozzle 15, blocks the light beam 14B from the light source 14A. The height (W-T) at which the small component P3 must be distinguished is smaller than the heights (W-T) at which the large and medium components P1 and P2 must be distinguished. However, the difference in component height at which small component P3 blocks light beam 14B during normal and abnormal suction (i.e., the height at which discrimination is required (W-T)) is such that slit 141C is located on the upper side, and light beam 14B from light source 14A is significantly stronger than the lower and central sides in the overall intensity balance. In other words, the value of the height at which discrimination is required for small component P3 (W-T) is smaller than the values ​​of the heights at which discrimination is required for large components P1 and medium components P2. However, because the position in the y direction at which small component P3 blocks light beam 14B (component height) is above slit 141C in the intensity balance of light beam 14B, the amount of light received by photodiode 14D when small component P3 blocks light beam 14B is expected to be the same as that received by large components P1 and medium components P2.Therefore, similar to the large and medium components P1 and P2, the judgment unit 17A can accurately determine (detect) whether the small component P3 picked up by the suction nozzle 15 is being picked up normally or abnormally based on a comparison between the threshold value 19C for small components and the difference in the amount of received light corresponding to the required height (WT) of the small component P3.

[0059] 3. Example of Arrangement for Improving Bias in the Amount of Light Received by the Photodiode Next, with reference to FIGS. 10 to 13 , an example of an arrangement for imposing a bias on the amount of light ray 14B received by the photodiode 14D depending on the position of the slit 141C will be described. FIG. 10( a) is a diagram showing an example of the correspondence between the state of a large component and a small component normally or abnormally picked up by the suction nozzle before they cross the light from the light source when the light source side is imposed with varying light intensity in the y direction, and the cross-sectional intensity distribution and the change in the photodiode output value over time in this state, according to the present embodiment. FIG. 10( b) is a diagram showing an example of an arrangement for imposing varying light intensity in the y direction on the light source side, according to the present embodiment. FIG. 11 is a diagram showing an example of an arrangement for imposing varying light intensity in the y direction on the light receiving side, according to the present embodiment, and the correspondence between the cross-sectional intensity distribution and the change in the photodiode output value over time in this state. FIG. 12 is a diagram showing another example of an arrangement for imposing varying light intensity in the y direction on the light receiving side, according to the present embodiment, and the correspondence between the cross-sectional intensity distribution and the change in the photodiode output value over time in this state. 13A is a diagram showing another example of a configuration and arrangement for varying the intensity of light in the y direction on the light receiving side according to the present embodiment, and an example of the correspondence relationship between the cross-sectional intensity distribution in that state and the change in the photodiode output value over time. FIG. 13B is a diagram showing the state as viewed from the light source side in the z direction, as seen from the x direction of FIG. 13A.

[0060] (1) First Configuration Example: Light Source Side Arrangement As shown in FIG. 10B, a gradation ND filter FL1 is arranged along the y direction downstream of the light source 14A. Here, "rear" refers to a position between the light source 14A and the slit 14C. Between the light source 14A and the slit 14C, the filter may be located either closer to the light source 14A or closer to the slit 14C. The gradation ND filter FL1 has the property of gradually reducing the intensity of light LG0 from the light source 14A in the y direction, from an upper position closer to the suction nozzle 15 to a lower position farther from the suction nozzle 15. As a result, the intensity of light LG1 transmitted through the gradation ND filter FL1 is gradually reduced in the y direction, from an upper position closer to the suction nozzle 15 to a lower position farther from the suction nozzle 15.

[0061] 10A, with the gradation ND filter FL1 disposed downstream of the light source 14A, a large component P1 and a small component P3 cross the light LG1. The determination unit 17A detects whether the large component P1 and the small component P3 are normally or abnormally attached based on a comparison of the photodiode output value at this time with the respective threshold values ​​19C for the large component P1 and the small component P3. As shown in the cross-sectional intensity distribution GR1i and the change over time GR2i in the photodiode output value, for the large component P1 and the small component P3, the difference between the amount of drop in the photodiode output value from the reference value (P0) during normal attachment and the amount of drop in the photodiode output value from the reference value (P0) during abnormal attachment is obtained to an extent that can be distinguished by the determination unit 17A. This is because, as explained with reference to Figures 8(b), 9(a) and 9(b), the intensity of light LG1 is high on the side closer to the tip of the suction nozzle 15 in the y direction, and the intensity of light LG1 is low on the side farther from the tip of the suction nozzle 15.

[0062] (2) Second Configuration Example: Light-Receiving Side Arrangement As shown in FIG. 11 , the z-direction width of the slit 14Ca is gradually narrowed from the upper position closer to the suction nozzle 15 toward the lower position farther from the suction nozzle 15 in the y direction. Note that the configuration of the slit 14Ca is not limited to the example described above, as long as the z-direction width of the slit gradually narrows from the upper position closer to the suction nozzle 15 toward the lower position farther from the suction nozzle 15 in the y direction. For example, a slit 14Cb having multiple rectangular slits may be arranged so that the overall z-direction width of the slit gradually narrows from the upper position closer to the suction nozzle 15 toward the lower position farther from the suction nozzle 15 in the y direction. Alternatively, a slit 14C having slits of the same width in the y direction may be combined with a gradation ND filter FL2. Similar to the gradation ND filter FL21, the gradation ND filter FL2 has a characteristic of strongly attenuating the amount of received light in the y direction from the upper position closer to the suction nozzle 15 toward the lower position farther from the suction nozzle 15.

[0063] (3) Third Configuration Example: Light Source Side Arrangement + Light Receiving Side Arrangement As shown in FIG. 12 , a polarizing plate PLZ1 whose light deflection angle gradually changes from 0° to 90° along the y direction is arranged downstream of the light source 14A. When light from the light source 14A passes through the polarizing plate PLZ1, the intensity of the light gradually decreases in the y direction from an upper position closer to the suction nozzle 15 toward a lower position farther from the suction nozzle 15. Furthermore, a polarizing plate PLZ2 whose light deflection angle gradually changes from 0° to 90° along the y direction is arranged between the slit 14C and the photodiode 14D. When a light ray 14B, which is transmitted light that has passed through or is transmitted by the slit 14C, passes through the polarizing plate PLZ2, the intensity of the light gradually decreases in the y direction from an upper position closer to the suction nozzle 15 toward a lower position farther from the suction nozzle 15. 12 shows a configuration in which the polarizing plate PLZ1 is disposed on the light source 14A side and the polarizing plate PLZ2 is disposed on the light-receiving side, but both polarizing plates (i.e., polarizing plates PLZ1 and PLZ2) may be disposed on only at least one of the light source 14A side and the light-receiving side. However, if the light source 14A has the polarizing plate PLZ1 or the light source itself has a polarizing plate, one more polarizing plate PLZ2 may be disposed on the light source 14A side, or one more polarizing plate PLZ2 may be disposed on the light-receiving side.

[0064] (4) Fourth Configuration Example: Light Source Side Arrangement + Light Receiving Side Arrangement In the first to third configuration examples described above, configuration examples have been described in which the light LG0 from the light source 14A is gradually reduced in the y direction from an upper position close to the suction nozzle 15 toward a lower position far from the suction nozzle 15. As a fourth configuration example, a configuration example will be described in which the light LG0 from the light source 14A is gradually reduced in the x direction, not in the y direction, from an upper position close to the suction nozzle 15 toward a lower position far from the suction nozzle 15. As shown in FIG. 13(b), it is assumed that the suction nozzle 15 that has picked up the component P crosses the measurement system 14 in the x direction.

[0065] In the fourth configuration example, the intensity of the light beam 14B from the light source 14A gradually increases in the x direction, parallel to the direction in which the suction nozzle 15 crosses the measurement system 14 (from the left side of the drawing to the right side of the drawing in FIG. 13B ). This can be achieved, for example, by arranging the gradation ND filter FL1 described with reference to FIG. 10B in the x direction. Furthermore, as shown in FIGS. 13A and 13B , the slit opening of the slit 14Cc is formed obliquely in the xz plane. Specifically, the slit 14Cc has an oblique slit opening such that the lower end is the front side where the suction nozzle 15 crosses the light beam 14B and the upper end is the rear side where the suction nozzle 15 crosses the light beam 14B. As a result, the intensity of the light beam 14B is minimum on the front side where the suction nozzle 15, which has picked up the component P, crosses the light beam 14B, and then gradually increases until the intensity of the light beam 14B is maximum on the rear side where the suction nozzle 15 crosses the light beam 14B. Therefore, similar to what has been described with reference to Figures 8(b), 9(a) and (b), the judgment unit 17A can detect with high accuracy whether the suction state of the component P picked up by the suction nozzle 15 is normal or abnormal, regardless of the size of the component P.

[0066] In the above-described embodiment, an example of a configuration has been described for detecting whether the state of pickup of a large component P1, a medium component P2, or a small component P3 by the suction nozzle 15 is normal or abnormal. It is also possible to make it easier to detect whether a component of a particular size (e.g., medium component P2) is picked up by the suction nozzle 15 normal or abnormally than components of other sizes (e.g., large component P1, small component P3), as shown in Fig. 14. Fig. 14 shows an example of the change over time in the photodiode output value when the detection sensitivity is increased to make the pickup state of a medium component P2 easier to detect than components of other sizes.

[0067] 14 differs from the photodiode 14D described above in that the photodiode 14Da shown in FIG. 14 has a peak sensitivity of its output value relative to the size of the medium component P2, for example. Specifically, as shown in the cross-sectional intensity distribution GR1j, the sensitivity to changes in the shading of the medium component P2 caused by the medium component P2 crossing the light beam 14B is higher than the sensitivity to changes in the shading of the other components (large component P1, small component P3) caused by the other components crossing the light beam 14B. This allows the determination unit 17A to more easily detect whether the suction state of the medium component P2 picked up by the suction nozzle 15 is normal or abnormal, compared to the large component P1 and small component P3.

[0068] (Additional Notes) The above description of the embodiments discloses the following items that are technical concepts.

[0069] (Item 1) A suction detection device (mounting machine 100) that detects a suction state of a component (P) by a suction nozzle (15) that mounts the component on a substrate (13), comprising: a light source (14A); a slit (14C) that transmits light from the light source; a light receiving element (photodiode 14D) that receives the transmitted light that has passed through the slit; and a processor (17) that detects the suction state based on a transition in the amount of light received by the light receiving element of the transmitted light before and after the component picked up by the suction nozzle crosses an optical path between the light source and the slit, wherein the amount of light received by the light receiving element before the component picked up by the suction nozzle crosses the optical path gradually decreases from an upper position close to the suction nozzle to a lower position far from the suction nozzle. As a result, the suction detection device can obtain an approximately equal difference between the amount of light received by the light-receiving element when a component is normally sucked and the amount of light received by the light-receiving element when a component is abnormally sucked, regardless of the size of the component, and therefore can detect with high accuracy the state in which a component is sucked onto the suction nozzle, regardless of the size of the component.

[0070] (Item 2) The suction detection device according to Item 1, wherein the processor detects the suction state based on a comparison between a drop in the amount of received light resulting from the component blocking the optical path according to the size of the component and a threshold value for the drop in amount according to the size of the component. As a result, the suction detection device can easily and accurately detect the state of a component being suctioned to the suction nozzle regardless of the size of the component based on a comparison between a change in the amount of received light at the light receiving element before and after the component crosses the light beam from the light source for each size of the component and a threshold value set in advance for each size.

[0071] (Item 3) The suction detection device according to Item 1 or 2, further comprising a filter (gradation ND filter FL1) provided between the light source and the light receiving element, the filter having a characteristic of gradually reducing the amount of light from the light source from an upper portion closer to the suction nozzle to a lower portion farther from the suction nozzle. As a result, the suction detection device can gradually reduce the amount of light (light beam) from the light source received by the light receiving element from the side closer to the tip of the suction nozzle to the side farther from the tip in the y direction (see FIG. 1 ), for example, and can detect with high accuracy the state of a component being sucked onto the suction nozzle regardless of the size of the component.

[0072] (Item 4) The slit has a slit hole that gradually narrows from an upper portion close to the suction nozzle toward a lower portion farther from the suction nozzle. As a result, with the suction detection device, the amount of light (light beam) received by the light receiving element of the light source can be gradually reduced from the side closer to the tip of the suction nozzle toward the side farther from the tip in, for example, the y direction (see FIG. 1 ), and the state of a component being sucked onto the suction nozzle can be detected with high accuracy regardless of the size of the component.

[0073] (Item 5) The suction detection device according to Item 1 or 2, further comprising a second filter (gradation ND filter FL2) disposed between the slit and the light-receiving element, the second filter having a characteristic of gradually reducing the amount of light from the light source from an upper side closer to the suction nozzle toward a lower side farther from the suction nozzle. This allows the suction detection device to gradually reduce the amount of light (light beam) from the light source received by the light-receiving element from the side closer to the tip of the suction nozzle toward the side farther from the tip in, for example, the y direction (see FIG. 1 ), and enables highly accurate detection of the state of a component being sucked onto the suction nozzle regardless of the size of the component.

[0074] (Item 6) The suction detection device according to Item 1 or 2, wherein a first polarizing plate (polarizing plate PLZ1) is provided between the light source and the slit, and a second polarizing plate (polarizing plate PLZ2) is provided between the slit and the light receiving element, and the first polarizing plate and the second polarizing plate have polarization characteristics that gradually reduce the amount of light from the light source from an upper portion closer to the suction nozzle toward a lower portion farther from the suction nozzle. As a result, the suction detection device can gradually reduce the amount of light (light beam) from the light source received by the light receiving element from a side closer to the tip of the suction nozzle toward a side farther from the tip in, for example, the y direction (see FIG. 1 ), and can detect with high accuracy the state of a component being sucked onto the suction nozzle regardless of the size of the component.

[0075] (Item 7) The suction detection device according to Item 1, wherein the amount of light received by the light-receiving element before the component picked up by the suction nozzle crosses the optical path gradually increases along the direction of movement of the suction nozzle, and the slit is provided in a diagonal right-shouldered shape along the direction of movement of the suction nozzle. As a result, the suction detection device can gradually reduce the amount of light (light beam) received by the light-receiving element from the light source in, for example, the x direction (see FIG. 1 ) from the side closer to the tip of the suction nozzle to the side farther from it, not limited to the y direction (see FIG. 1 ), and can detect with high accuracy the state of a component being picked up by the suction nozzle regardless of the size of the component.

[0076] (Item 8) A suction detection method for detecting a suction state of a component by a suction nozzle that places the component on a board, comprising: receiving light from a light source that is transmitted through a slit with a light receiving element; and detecting the suction state based on a transition in the amount of light received by the light receiving element of the transmitted light before and after the component picked up by the suction nozzle crosses the optical path between the light source and the slit, wherein the amount of light received by the light receiving element before the component picked up by the suction nozzle crosses the optical path gradually decreases from an upper position closer to the suction nozzle to a lower position farther from the suction nozzle. As a result, the suction detection method can obtain a substantially uniform difference between the amount of light received by the light receiving element when the component is normally picked up and the amount of light received by the light receiving element when the component is abnormally picked up, regardless of the size of the component, thereby enabling highly accurate detection of the state of the component being picked up by the suction nozzle regardless of the size of the component.

[0077] Although various embodiments have been described above with reference to the accompanying drawings, the present disclosure is not limited to such examples. It is clear that those 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 fall within the technical scope of the present disclosure. Furthermore, the components of the various embodiments described above may be combined in any manner without departing from the spirit of the invention.

[0078] This application is based on a Japanese patent application (Patent Application No. 2024-108896) filed on July 5, 2024, the contents of which are incorporated herein by reference.

[0079] The present disclosure is useful as a suction detection device and a suction detection method that can detect with high accuracy the state in which a component is sucked onto a suction nozzle regardless of the size of the component.

[0080] REFERENCE SIGNS LIST 11 Mounting head 12 Component supply unit 13 Board 14 Measurement system 14A Light source 14B Light beam 14C Slit 14D Photodiode 14E Current-voltage conversion unit 15 Suction nozzle 17 Processor 17A Determination unit 18 Mounting operation control unit 19 Memory 19A Reference value 19B Threshold value 20 Output unit 21 Communication unit 31 Management computer 100 Mounting machine 141C Slit hole

Claims

1. A suction detection device that detects the suction state of a component by a suction nozzle that places the component on a board, comprising: a light source; a slit that transmits light from the light source; a light receiving element that receives the transmitted light that has passed through the slit; and a processor that detects the suction state based on the change in the amount of transmitted light received by the light receiving element before and after the component picked up by the suction nozzle crosses the optical path between the light source and the slit, wherein the amount of light received by the light receiving element before the component picked up by the suction nozzle crosses the optical path gradually decreases from an upper position close to the suction nozzle to a lower position far from the suction nozzle.

2. The suction detection device according to claim 1, wherein the processor detects the suction state based on a comparison between a drop in the amount of received light resulting from the component blocking the optical path according to the size of the component and a threshold value for the drop in the amount of light according to the size of the component.

3. The suction detection device according to claim 1, wherein a filter is provided between the light source and the light receiving element, and the filter has the property of gradually reducing the light from the light source from an upper position close to the suction nozzle toward a lower position far from the suction nozzle.

4. The suction detection device according to claim 1, wherein the slit has a slit hole that gradually narrows from an upper portion close to the suction nozzle toward a lower portion farther from the suction nozzle.

5. The suction detection device according to claim 1, further comprising a second filter disposed between the slit and the light receiving element, the second filter having a characteristic of gradually reducing the intensity of light from the light source from an upper position close to the suction nozzle toward a lower position farther from the suction nozzle.

6. The suction detection device according to claim 1, wherein a first polarizing plate is provided between the light source and the slit, and a second polarizing plate is provided between the slit and the light receiving element, and the first polarizing plate and the second polarizing plate have polarization characteristics that gradually reduce the light from the light source from an upper portion close to the suction nozzle toward a lower portion far from the suction nozzle.

7. The suction detection device according to claim 1, wherein the amount of light received by the light receiving element before the component picked up by the suction nozzle crosses the optical path gradually increases along the direction of movement of the suction nozzle, and the slit is provided in an oblique, upward-sloping shape along the direction of movement of the suction nozzle.

8. A suction detection method for detecting the suction state of a component by a suction nozzle that places the component on a board, comprising: receiving light from a light source that has passed through a slit with a light receiving element; and detecting the suction state based on the change in the amount of transmitted light received by the light receiving element before and after the component picked up by the suction nozzle crosses the optical path between the light source and the slit, wherein the amount of light received by the light receiving element before the component picked up by the suction nozzle crosses the optical path gradually decreases from an upper position close to the suction nozzle to a lower position far from the suction nozzle.

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