Quality change detection method, quality change detection system, and program

Abstract

The problem addressed by the present disclosure is that of pre-empting and preventing the defective mounting of a second target object on a first target object. The quality change detection method according to the present disclosure includes an acquisition step and a first determination step. In the acquisition step, a mounting position deviation amount is acquired, which is the difference between a target position and the actual position of the mounting of a second target object (T2) on a first target object (T1). In the first determination step, mounting quality is determined to have changed if the mounting position deviation amount acquired in the acquisition step exceeds a first determining range and is within a second determining range. The first determining range is included in the second determining range, in which the mounting quality is determined to be normal.

Description

[Technical field]

[0001] The present disclosure generally relates to a quality change detection method, a quality change detection system, and a program. [Background technology]

[0002] Patent Document 1 describes a mounted component inspection device for inspecting the mounting state of components on a printed circuit board. The mounted component inspection device described in Patent Document 1 detects mounting defects of components based on captured images of the mounting positions of the components on the printed circuit board. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2000-349499 A Summary of the Invention

[0004] An object of the present disclosure is to provide a quality change detection method, a quality change detection system, and a program that can prevent the occurrence of mounting defects of a second object on a first object.

[0005] A quality change detection method according to one aspect of the present disclosure includes an acquisition step and a first determination step. The acquisition step is a step of acquiring a mounting position deviation amount, which is a difference between an actual mounting position of a second object relative to a first object and a target mounting position. The first determination step is a step of determining that mounting quality has changed when the mounting position deviation amount acquired in the acquisition step exceeds a first determination range and falls within a second determination range. The first determination range is included in the second determination range in which the mounting quality is determined to be normal. The quality change detection method further includes a second determination step of determining that the mounting quality has changed based on statistical information regarding the mounting position deviation amount included in the first determination range. A quality change detection method according to another aspect of the present disclosure includes an acquisition step and a first determination step. The acquisition step is a step of acquiring a mounting position deviation amount, which is a difference between an actual mounting position of a second object relative to a first object and a target mounting position. The first determination step is a step of determining that the mounting quality has changed when the mounting position deviation amount acquired in the acquisition step exceeds a first determination range and falls within a second determination range. The first determination range is included in the second determination range in which the mounting quality is determined to be normal. The first determination range is set according to a mounting angle of the second object relative to the first object. A quality change detection method according to another aspect of the present disclosure includes an acquisition step and a first determination step. The acquisition step is a step of acquiring a mounting position deviation amount, which is a difference between an actual mounting position of a second object relative to a first object and a target mounting position. The first determination step is a step of determining that the mounting quality has changed when the mounting position deviation amount acquired in the acquisition step exceeds a first determination range and falls within a second determination range. The first determination range is included in the second determination range in which the mounting quality is determined to be normal. The quality change detection method further includes a prediction step of predicting an abnormality in the mounting quality based on first information regarding the mounting position deviation amount. A quality change detection method according to another aspect of the present disclosure includes an acquisition step and a first determination step. The acquisition step is a step of acquiring a mounting position deviation amount, which is a difference between an actual mounting position of a second object relative to a first object and a target mounting position. The first determination step is a step of determining that the mounting quality has changed when the mounting position deviation amount acquired in the acquisition step exceeds a first determination range and falls within a second determination range. The first determination range is included in the second determination range in which the mounting quality is determined to be normal. The quality change detection method further includes an estimation step of estimating a malfunction location in a mounting system that is a factor of the change in the mounting quality, based on first information related to the mounting position deviation amount. In the estimation step, in addition to the first information, second information related to equipment used when mounting the second object relative to the first object, which is information corresponding to the mounting position deviation amount, is used.

[0006] A quality change detection system according to an embodiment of the present disclosure includes an acquisition unit and a determination unit. The acquisition unit acquires a mounting position deviation amount, which is a difference between an actual mounting position of a second object relative to a first object and a target mounting position. The determination unit determines that mounting quality has changed when the mounting position deviation amount acquired by the acquisition unit exceeds a first determination range and falls within a second determination range. The first determination range is included in the second determination range in which the mounting quality is determined to be normal. The quality change detection system further includes a second determination unit that determines that the mounting quality has changed based on statistical information regarding the mounting position deviation amount included in the first determination range. A quality change detection system according to another aspect of the present disclosure includes an acquisition unit and a determination unit. The acquisition unit acquires a mounting position deviation amount, which is a difference between an actual mounting position of a second object relative to a first object and a target mounting position. The determination unit determines that the mounting quality has changed when the mounting position deviation amount acquired by the acquisition unit exceeds a first determination range and falls within a second determination range. The first determination range is included in the second determination range in which the mounting quality is determined to be normal. The first determination range is set according to a mounting angle of the second object relative to the first object. A quality change detection system according to another aspect of the present disclosure includes an acquisition unit and a determination unit. The acquisition unit acquires a mounting position deviation amount, which is a difference between an actual mounting position of a second object relative to a first object and a target mounting position. The determination unit determines that the mounting quality has changed when the mounting position deviation amount acquired by the acquisition unit exceeds a first determination range and falls within a second determination range. The first determination range is included in the second determination range in which the mounting quality is determined to be normal. The quality change detection system further includes a prediction unit that predicts an abnormality in the mounting quality based on first information related to the mounting position deviation amount. A quality change detection system according to another embodiment of the present disclosure includes an acquisition unit and a determination unit. The acquisition unit acquires a mounting position deviation amount, which is a difference between an actual mounting position of a second object relative to a first object and a target mounting position. The determination unit determines that the mounting quality has changed when the mounting position deviation amount acquired by the acquisition unit exceeds a first determination range and falls within a second determination range. The first determination range is included in the second determination range in which the mounting quality is determined to be normal. The quality change detection system further includes an estimation unit that estimates a malfunction location in a mounting system that is a factor of the change in the mounting quality based on first information related to the mounting position deviation amount. The estimation unit uses second information related to equipment used when mounting the second object relative to the first object, which is information corresponding to the mounting position deviation amount, in addition to the first information.

[0007] A program according to one aspect of the present disclosure is a program for causing one or more processors to execute the quality change detection method. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic configuration diagram of a substrate production line to which a quality change detection system according to an embodiment is applied. [Diagram 2] FIG. 2 is a schematic plan view of a mounting system that is a detection target of the quality change detection system. [Diagram 3] FIG. 3 is a cross-sectional view taken along line AA of FIG. [Figure 4] FIG. 4 is a block diagram of the above quality change detection system. [Diagram 5] FIG. 5 is a block diagram of an implementation system that is a detection target of the above quality change detection system. [Figure 6] Fig. 6A is a diagram showing a distribution of mounting positions of a second object relative to a first object, generated by the above quality change detection system. Fig. 6B is a diagram showing a distribution of mounting positions of a second object relative to a first object for each mounting angle of the second object relative to the first object, generated by the above quality change detection system. [Figure 7]FIG. 7 is a graph showing the amount of mounting position deviation of a second object relative to a first object, generated by the above-mentioned quality change detection system, in a case where a second object is not mounted properly relative to the first object. [Figure 8] FIG. 8 is an explanatory diagram for explaining the first detection process of the quality change detection system. [Figure 9] 9A to 9C are graphs for explaining the second detection process of the quality change detection system according to the first embodiment. [Figure 10] FIG. 10 is a flowchart showing a quality change detection method executed by the above quality change detection system. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] (Embodiment) Hereinafter, a quality change detection method and a quality change detection system according to an embodiment will be described with reference to the drawings. However, the embodiment and modified examples described below are merely examples of the present disclosure, and the present disclosure is not limited to the following embodiment and modified examples. Even if the embodiment and modified examples are not described below, various modifications can be made according to the design, etc., as long as they do not deviate from the technical idea of ​​the present disclosure.

[0010] In addition, all of the drawings described in the following embodiments are schematic drawings, and the ratios of size and thickness of each component in each drawing do not necessarily reflect the actual dimensional ratios.

[0011] The mounted component inspection device (quality change detection system) described in Patent Document 1 can detect the occurrence of mounting defects of a component (second object) on a printed circuit board (first object), but cannot prevent the occurrence of mounting defects in advance.

[0012] (1) Overview First, an overview of a quality change detection method and a quality change detection system 1 according to the present embodiment will be described with reference to FIGS. 1 to 3. FIG.

[0013] The quality change detection method according to this embodiment is a method for detecting a change in the quality of processing of a first object T1. A quality change detection system 1 according to this embodiment is a system used in the above-mentioned quality change detection method. As shown in Figs. 2 and 3, a mounting system 22 mounts (processes) a second object T2 on a first object T1. The mounting system 22 is a mounting device (mounting machine) used in operations for manufacturing various products such as electronic devices, automobiles, clothing, food, medicines, and crafts in facilities such as factories, laboratories, offices, and educational facilities.

[0014] In this embodiment, a case will be described in which the mounting system 22 is used in the manufacture of electronic devices in a factory. A typical electronic device has various circuit boards, such as a power supply circuit and a control circuit. In the manufacture of these circuit boards, as an example, a solder application process, a mounting process, and a reflow process are performed in this order. In the solder application process, cream solder is applied (or printed) to a board (including a printed wiring board). In the mounting process, components (including electronic components) are mounted (mounted) on the board. In the reflow process, for example, the board on which the components are mounted is heated in a reflow furnace to melt the cream solder and perform soldering.

[0015] In addition, three inspection steps (first to third inspection steps) are performed between the solder application step and the mounting step, between the mounting step and the reflow step, and after the reflow step. In the first inspection step, the application state of the cream solder on the board (position, size, film thickness, etc. of the cream solder on the board) is inspected. In the second inspection step, the mounting state of the second object T2 on the first object T1 before the reflow step is performed (mounting position, mounting angle, etc. of the second object T2 on the first object T1) is inspected. In the third inspection step, the mounting state of the second object T2 on the first object T1 after the reflow step is performed (mounting position, mounting angle, etc. of the second object T2 on the first object T1) is inspected.

[0016] These steps are performed in a board manufacturing line 2 shown in Fig. 1. The board manufacturing line 2 includes a printing system 21, a mounting system 22, a reflow system 23, a post-printing inspection system 24, a post-mounting inspection system 25, and a post-reflow inspection system 26.

[0017] In a solder application process, a printing system 21 (see FIG. 1) prints solder on a board 100 serving as a first object T1. In a mounting process, a mounting system 22 (see FIG. 1) mounts a component 200 serving as a second object T2 on the board 100 serving as the first object T1. A reflow system 23 heats the board 100 on which the component 200 has been mounted via solder, melting the solder and soldering the component 200 to the board 100.

[0018] A post-printing inspection system 24 (see FIG. 1) inspects the printing state of the solder printed on the board 100, which is the first object T1, in a first inspection process. A post-mounting inspection system 25 (see FIG. 1) inspects the mounting state of the second object T2 on the first object T1 in a second inspection process. A post-reflow inspection system 26 (see FIG. 1) inspects the mounting state of the second object T2 on the first object T1 after reflow in a third inspection process.

[0019] Each piece of equipment constituting the board production line 2 is connected to the quality change detection system 1 via a wired or wireless communication network, and data is transmitted and received between each piece of equipment and the quality change detection system 1. Here, the printing system 21, the mounting system 22, the reflow system 23, the post-printing inspection system 24, the post-mounting inspection system 25, and the post-reflow inspection system 26 each refer in principle to a single device, but also include a configuration in which the control unit or memory unit of the device is located outside the device, or a configuration in which the functions of the device are realized by combining multiple modules. Also includes a configuration in which multiple devices of the same type are grouped together.

[0020] The quality change detection system 1 according to this embodiment detects a change in quality of a first object T1 manufactured in a board manufacturing line 2 (see FIG. 1) based on first information D1. The first information D1 is information acquired in a second inspection process, and is input from a post-mounting inspection system 25 described later.

[0021] That is, the quality change detection method according to the present embodiment is a method for detecting a change in the quality of mounting when a second object T2 is mounted on a first object T1 in a mounting process. The mounting quality control method includes an acquisition step and a first determination step (steps ST1 to ST3 in FIG. 10). The acquisition step is a step of acquiring data related to the component 200 to be detected from a mounting position deviation amount, which is a difference between an actual mounting position of the second object T2 on the first object T1 and a target mounting position, contained in the first information D1 from the post-mounting inspection system 25. The acquired data is grouped by component type or mounting angle, for example. The first determination step is a step of determining that the quality of mounting has changed when the mounting position deviation amount acquired in the acquisition step exceeds a first determination range R1 (see FIG. 7) and falls within a second determination range R2 (see FIG. 7). The second determination range R2 is a range in which the quality of mounting is determined to be normal.

[0022] Moreover, the quality change detection system 1 according to this embodiment is a system used in the above-mentioned quality change detection method. As shown in FIG. 4, the quality change detection system 1 includes an acquisition unit 11 and a judgment unit 12. The acquisition unit 11 acquires a mounting position deviation amount, which is a difference between an actual mounting position and a target mounting position of the second object T2 on the first object T1 after a mounting process in which the second object T2 is mounted on the first object T1. The judgment unit 12 judges that the mounting quality has changed when the mounting position deviation amount acquired by the acquisition unit 11 exceeds a first judgment range R1 (see FIG. 7) and falls within a second judgment range R2 (see FIG. 7). The second judgment range R2 is a range in which the mounting quality is judged to be normal.

[0023] In this disclosure, “normal mounting quality” means that the quality satisfies at least the range that is determined to be normal by the post-mounting inspection system 25 that outputs information to the quality change detection system 1.

[0024] In the quality change detection method and quality change detection system 1 according to this embodiment, even if the mounting position deviation amount is within the second judgment range R2 in which the mounting quality is judged to be normal, if it exceeds the first judgment range R1, it is judged that the mounting quality has changed. Therefore, it is possible to know that the mounting quality has changed in a direction that will cause an abnormality (failure) before the mounting position deviation amount exceeds the second judgment range R2. This makes it possible to prevent the occurrence of mounting defects of the second object T2 on the first object T1.

[0025] (2)Details Next, the quality change detection method and quality change detection system 1 according to the present embodiment will be described in detail with reference to FIGS.

[0026] (2.1) Premise In the present embodiment, as an example, a case will be described in which the mounting system 22 is used to mount a component (second object T2) by surface mount technology (SMT). That is, the component 200 as the second object T2 is a surface mount component (SMD: Surface Mount Device), and is mounted by being placed on the surface (mounting surface 101) of the board 100 as the first object T1. However, the present invention is not limited to this example, and the mounting system 22 may be used to mount a component (second object T2) by insertion mount technology (IMT). In this case, the component 200 as the second object T2 is a component for insertion mounting having lead terminals, and is mounted on the surface (mounting surface 101) of the board 100 by inserting the lead terminals into holes in the board 100 as the first object T1.

[0027] That is, "mounting" in the present disclosure includes arranging a component 200 as a second object T2 on the mounting surface 101 of a substrate 100 as a first object T1, attaching the component 200 to the mounting surface 101 of the substrate 100, and inserting a lead terminal of the component 200 into a hole in the substrate 100. Furthermore, "mounting" in the present disclosure includes joining the component 200 to the substrate 100 and gluing the component 200 to the substrate 100.

[0028] Furthermore, the "quality of mounting" in this disclosure refers to the quality when a component 200 as a second object T2 is mounted on a board 100 as a first object T1, and includes the mounting position and mounting angle of the component 200 with respect to the board 100. More specifically, the "quality of mounting" includes the mounting position in a first direction (X-axis direction) of the board 100, the mounting position in a second direction (Y-axis direction) of the board 100, and the mounting angle within the mounting surface 101 of the board 100.

[0029] In addition, in the present disclosure, "the mounting quality changes" refers to a change in the direction away from the range in which the mounting quality is judged to be normal (i.e., a change in the direction in which the mounting quality is judged to be abnormal). For example, in this embodiment, this refers to a change in the mounting position (or mounting angle) of the second object T2 relative to the first object T1.

[0030] In addition, in this disclosure, "determining that the mounting quality has changed" means determining whether or not the amount of deviation of the mounting position (or mounting angle) of the second object T2 relative to the first object T1 exceeds a first judgment range R1 (see FIG. 5) included in a second judgment range R2 (see FIG. 5) in which the mounting quality is determined to be normal, or that the distribution of the amount of deviation of the mounting position (or mounting angle) of the second object T2 that falls within the first judgment range R1 has changed.

[0031] Furthermore, the term "target mounting position" in this disclosure refers to a position (coordinates) where a component 200 as a second target T2 is to be mounted on a board 100 as a first target T1. In this embodiment, as shown in Fig. 2, since the board 100 is placed parallel to an XY plane described below, the target mounting position is expressed by a coordinate in the X-axis direction (X coordinate) and a coordinate in the Y-axis direction (Y coordinate).

[0032] In the following, as an example, three mutually orthogonal axes, X-axis, Y-axis, and Z-axis, are set, and the axes parallel to the surface (mounting surface 101) of the substrate 100, which is the first object T1, are defined as the "X-axis" and "Y-axis", and the axis parallel to the thickness direction of the substrate 100 is defined as the "Z" axis. Furthermore, the side of the capture unit 2211 seen from the substrate 100, which is the first object T1, is defined as the positive direction of the Z axis (also referred to as "above"). In addition, the state seen from the positive direction of the Z axis (above) is also referred to as "planar view" below. The X-axis, Y-axis, and Z-axis are all imaginary axes, and the arrows indicating "X", "Y", and "Z" in the drawings are merely indicated for the purpose of explanation, and none of them have any substance. Furthermore, these directions are not intended to limit the directions in which the mounting system 22 is used.

[0033] In addition, pipes for circulating cooling water, cables for supplying power, pipes for supplying air pressure (including positive pressure and vacuum), etc. are connected to the mounting system 22, but in this embodiment, these are appropriately omitted from the illustration.

[0034] (2.2) Quality change detection system Next, the configuration of the quality change detection system 1 according to this embodiment will be described with reference to FIG.

[0035] In this embodiment, the quality change detection system 1 mainly comprises a computer system having one or more processors and one or more memories. That is, the functions of the quality change detection system 1 are realized by one or more processors executing a program recorded in one or more memories of the computer system. The program may be pre-recorded in the memory, may be provided via a telecommunication line such as the Internet, or may be provided by recording it on a non-transitory recording medium such as a memory card.

[0036] 4, the quality change detection system 1 according to this embodiment includes an acquisition unit 11 and a determination unit 12. In this embodiment, in addition to the acquisition unit 11 and the determination unit 12, the quality change detection system 1 further includes a prediction unit 13, a factor estimation unit 14, a creation unit 15, and a notification unit 16.

[0037] In this embodiment, as described above, the quality change detection system 1 mainly comprises a computer system having one or more processors and one or more memories. Therefore, each component of the quality change detection system 1 (acquisition unit 11, judgment unit 12, prediction unit 13, factor estimation unit 14, creation unit 15, and notification unit 16) is realized by one or more processors executing programs.

[0038] (2.2.1) Acquisition part As described above, the acquisition unit 11 acquires the mounting position deviation amount, which is the difference between the actual mounting position of the second object T2 with respect to the first object T1 and the target mounting position. That is, the step (processing) in which the acquisition unit 11 acquires the mounting position deviation amount is the acquisition step of the quality change detection method according to this embodiment. Specifically, the acquisition unit 11 acquires the first information D1 from a post-mounting inspection system 25 (see FIG. 1) described later. The acquisition unit 11 may also acquire the second information D2 from a mounting system 22 described later. In this embodiment, the acquisition unit 11 acquires the first information D1 at the timing when the inspection of one board 100 as the first object T1 is completed in the post-mounting inspection system 25. Note that the acquisition unit 11 may acquire the first information D1 at the timing when the inspection of a required number of boards 100 is completed for distribution change detection F2 (see FIG. 10) described later. Moreover, in this embodiment, the acquisition unit 11 acquires the first information D1 for all the second objects T2 mounted on the mounting surface 101 of one board 100. The acquisition unit 11 outputs the acquired first information D1 to the determination unit 12 for each type of component 200.

[0039] The "type of component" here includes the type of element (resistor, capacitor, lead component, etc.) and the size of the component (0402, 0603, 1005, etc., not limited to actual dimensions, including dimensions according to standards and data). In addition, "by type of component" includes at least the meaning of by type of element, by size of component, and by type of element and by size of component. For example, the first information D1 of a resistor of 0603 size and the first information D1 of a resistor of 1005 size are output to the determination unit 12 separately. That is, even if the type of element is the same, when the sizes of the components are different, they are output to the determination unit 12 separately. Furthermore, the first information D1 may be output to the determination unit 12 for each type of component and each mounting angle. In this embodiment, the acquisition unit 11 acquires the first information D1 from a management computer 3 (see FIG. 4) that manages information on the devices constituting the board manufacturing line 2.

[0040] The first information D1 includes a mounting position deviation amount, which is a difference between an actual mounting position of the second object T2 relative to the first object T1 and a target mounting position of the second object T2 relative to the first object T1. The first information D1 may further include a mounting angle deviation amount, which is a difference between an actual mounting angle of the second object T2 relative to the first object T1 and a target mounting angle of the second object T2 relative to the first object T1. In this embodiment, it is assumed that only the mounting position deviation amount is included in the first information D1. The mounting position deviation amount includes a first mounting position deviation amount, which is a deviation amount in the X-axis direction, and a second mounting position deviation amount, which is a deviation amount in the Y-axis direction. The first information D1 includes the mounting position deviation amount before the reflow process is performed.

[0041] The second information D2 is information acquired from at least one of the facilities constituting the board manufacturing line 2. In this embodiment, the second information D2 is information acquired from the mounting system 22, which is one facility 4 of the facilities (see FIG. 4). The second information D2 includes lot information, trace information, event information, and production information (production data). The lot information is information about the type of the board 100 on which the component 200 corresponding to the above-mentioned first information D1 is mounted, and includes, for example, information about the production lot for each board 100 and the production date and time of the board 100. The trace information includes information about the address of the nozzle 2211 and feeder (i.e., the nozzle holder at which the component 200 was mounted and the feeder at which the component was supplied) used when mounting the component 200 corresponding to the above-mentioned first information D1, which will be described later, information acquired by a sensor (e.g., the component recognition camera 222) provided in the mounting system 22, and a correction amount (e.g., a recognition correction amount) based on the information acquired by the sensor. The event information is information about an event performed in the mounting process by the mounting system 22, and includes, for example, the replacement of a feeder. The production information includes, for example, a target mounting position of the component 200 on the board 100, a target mounting angle, a circuit number, and a component code that individually identifies the component 200. The component code includes information such as the size of the component, the type of element (i.e., resistor or capacitor), and the vendor of the component.

[0042] (2.2.2) Judgment part The judging unit 12 judges that the mounting quality has changed based on the first information D1 from the acquiring unit 11. More specifically, the judging unit 12 judges that the mounting quality has changed when the mounting position deviation amount from the acquiring unit 11 exceeds the first judgment range R1 (see FIG. 7) and falls within the second judgment range R2 (see FIG. 7) in which the mounting quality is judged to be normal. The judging unit 12 also judges that the mounting quality has changed based on statistical information related to the mounting position deviation amount included in the first judgment range R1. That is, the step (processing) in which the judging unit 12 judges that the mounting quality has changed is the judgment step (first judgment step and second judgment step) of the quality change detection method according to this embodiment.

[0043] The quality change detection method according to the present embodiment includes a first judgment step and a second judgment step as judgment steps. The first judgment step is a step of judging that the quality of mounting has changed when the amount of mounting position deviation exceeds the first judgment range R1 and falls within the second judgment range R2. The second judgment step is a step of judging that the quality of mounting has changed based on statistical information regarding the amount of mounting position deviation of the second object T2 included in the first judgment range R1. The first judgment range R1 is set based on the standard deviation of a normal state distribution (see FIG. 9A) created by the creation unit 15, which will be described later. In other words, the normal state distribution (see FIG. 9A) is a distribution that indicates how the amount of mounting position deviation of the second object T2 varies if the state of the board manufacturing line 2 is normal.

[0044] FIG. 6A is a diagram showing the distribution of mounting positions of the second object T2 relative to the first object T1 for each type of component and each production lot. In this embodiment, each type of component means each size of the component and each type of element. FIG. 6A shows the distribution of mounting positions of the second object T2 in the X-axis direction. In FIG. 6A, the graphs (two in the illustrated example) aligned along the horizontal axis show graphs of different production lots, and the graphs (two in the illustrated example) aligned along the vertical axis show graphs of different types of components. In addition, the vertical axis in each graph shows the amount of mounting position deviation, and the horizontal axis in each graph shows the number of times mounting is performed at each amount of mounting position deviation, i.e., the number of occurrences.

[0045] With reference to two graphs in which the type of components is the same but the production lots are different, arranged in the horizontal direction in FIG. 6A, it can be seen that even if the production lots are different, if the type of components is the same (i.e., if the type of the second object T2 is the same), the change in the distribution of the mounting positions of the second object T2 is small (the shape of the distribution can be considered to be equivalent). On the other hand, with reference to graphs in which the production lots are the same but the types of components are different, arranged in the vertical direction in FIG. 6A, it can be seen that even if the production lots are the same, if the types of components are different (i.e., if the type of the second object T2 is different), the change in the distribution of the mounting positions of the second object T2 is large (the shape of the distribution cannot be considered to be equivalent). In short, the distribution of the mounting positions of the second object T2 varies more greatly depending on the type of the second object T2 (component 200) than on the production lot. Therefore, it is preferable that the normal state distribution is set according to the type of the component 200, which is the second object T2. Here, it is preferable that the first judgment range R1 (see FIG. 8) is set according to the type of the second object T2. Similarly, the second judgment range R2 (see FIG. 8) is also preferably set according to the type of the second object T2.

[0046] The distribution of the mounting position deviation amount of the second object T2 in the Y-axis direction also varies more greatly depending on the type of component than on the production lot (the shape of the distribution cannot be considered to be the same). Therefore, only the distribution of the mounting position in the X-axis direction will be described here, and the description of the distribution of the mounting position deviation amount in the Y-axis direction will be omitted.

[0047] Fig. 6B is a diagram showing the distribution of the mounting positions of the second object T2 relative to the first object T1 for each mounting angle of the second object T2 relative to the first object T1. Fig. 6B shows the distribution of the mounting positions of the second object T2 in the X-axis direction, similar to Fig. 6A. The vertical axis in each graph indicates the amount of mounting position deviation, and the horizontal axis in each graph indicates the number of occurrences.

[0048] Further, the graph on the left side of FIG. 6B shows the case where the mounting angle of the second object T2 relative to the first object T1 is 90 degrees, and the graph on the right side of FIG. 6B shows the case where the mounting angle is 0 degrees. Comparing the graph when the mounting angle is 90 degrees with the graph when the mounting angle is 0 degrees, it can be seen that the distribution of the mounting position deviation amount of the second object T2 is different. In short, the distribution of the mounting position deviation amount of the second object T2 changes significantly depending on the mounting angle of the second object T2 relative to the first object T1 (the shapes of the distributions cannot be considered to be equivalent). Therefore, it is preferable that the normal state distribution is set according to the mounting angle of the component 200, which is the second object T2, relative to the first object T1. Here, it is preferable that the first judgment range R1 (see FIG. 8) is set according to the mounting angle of the component 200, which is the second object T2, relative to the first object T1. Similarly, the second determination range R2 is also preferably set according to the mounting angle of the component 200, which is the second object T2, relative to the first object T1.

[0049] (2.2.2.1) First judgment step (outlier detection F1) The first judgment range R1 is a range defined by a first threshold value TH11 and a second threshold value TH12, as shown in Fig. 7. Here, in this embodiment, the absolute values ​​of the first threshold value TH11 and the second threshold value TH12 are different from each other, but the absolute values ​​of the first threshold value TH11 and the second threshold value TH12 may be the same. In Fig. 7, the horizontal axis indicates the elapsed time t, and the vertical axis indicates the mounting position misalignment amount GapX of the second object T2.

[0050] As described above, the second judgment range R2 is a range in which the mounting quality is judged to be normal. As shown in FIG. 7, the second judgment range R2 is a range defined by the first threshold TH21 and the second threshold TH22. Here, in this embodiment, the absolute values ​​of the first threshold TH21 and the second threshold TH22 are different, but the absolute values ​​of the first threshold TH21 and the second threshold TH22 may be the same. Also, in FIG. 7, the "circle" exceeding the first threshold TH11 indicates an outlier of the mounting position deviation amount GapX of the second object T2. The "outlier" here refers to a value that falls within the second judgment range R2 but exceeds the first judgment range R1 (see "Ou1" and "Ou2" in FIG. 8). Note that "DI1" in FIG. 8 indicates the distribution of the mounting position deviation amount GapX of the second object T2 (hereinafter referred to as "distribution DI1").

[0051] Therefore, as described above, the determination unit 12 determines that the mounting quality has changed when the mounting position deviation amount GapX (the outliers Ou1, Ou2 in FIG. 8) exceeds the first determination range R1 and falls within the second determination range R2. That is, in this embodiment, the first determination range R1 is included in the second determination range R2, as shown in FIGS. 7 and 8.

[0052] Incidentally, the first judgment range R1 is set according to the type of the second object T2, as described above. Then, when the type of the second object T2 is different, the judgment unit 12 judges that the mounting quality of the second object T2 has changed based on the first judgment range R1 set according to the type of the second object T2. Also, as described above, the first judgment range R1 is set according to the mounting angle of the second object T2 with respect to the first object T1. Then, when the mounting angle of the second object T2 with respect to the first object T1 is different, the judgment unit 12 judges that the mounting quality has changed based on the first judgment range R1 set according to the mounting angle. Note that the judgment unit 12 may also judge that the mounting quality has changed based on the first judgment range R1 set according to the feeder (feeder serial number or address) used to mount the second object T2. That is, the determination unit 12 determines that the mounting quality has changed based on the determination criteria generated for each different category (type of the second object T2, mounting angle, feeder used for supply, etc.) This clarifies the deviation from the determination criteria for a specific category, and the change in mounting quality becomes apparent.

[0053] (2.2.2.2) Second judgment step (distribution change detection F2) Furthermore, when a certain number or more of the second objects T2 whose mounting position misalignment amounts are included in the first judgment range R1 are collected among the multiple second objects T2 mounted on the mounting surface 101 of the board 100 as the first object T1, the judgment unit 12 executes distribution change detection F2 (see FIG. 10) described below. That is, the judgment unit 12 judges that the mounting quality has changed based on statistical information regarding the mounting position misalignment amounts of the second objects T2 included in the first judgment range R1.

[0054] The statistical information includes at least one of an average calculated based on the distribution of the mounting position deviation amount of the second object T2 and a variance (or a standard deviation) calculated based on the distribution of the mounting position deviation amount of the second object T2. In this embodiment, the statistical information includes both an average calculated from the distribution of the mounting position deviation amount of the second object T2 and a variance (or a standard deviation) calculated from the distribution of the mounting position deviation amount of the second object T2. For example, as shown in FIG. 9B, when the difference between the average calculated from the distribution DI1 of the mounting position deviation amount of the second object T2 and the average calculated from the normal state distribution is large (above the threshold value of step ST7 in FIG. 10), the determination unit 12 determines that the mounting quality has changed. In addition, for example, as shown in FIG. 9C, when the ratio between the variance calculated from the distribution DI1 of the mounting position deviation amount of the second object T2 and the variance calculated from the normal state distribution is large (i.e., the distribution DI1 is wider than the normal state distribution), the determination unit 12 determines that the mounting quality has changed.

[0055] Fig. 9A is a diagram showing a normal state distribution obtained from past first information D1. In Fig. 9A, the distribution DI1 of the mounting position misalignment amount of the second object T2 is distributed with the vicinity of zero of the mounting position misalignment amount as the average. Also, the scale (value of the number of occurrences) on the left side in Fig. 9A to Fig. 9C is a scale for the normal state distribution, and the distribution DI1 of the mounting position misalignment amount of the second object T2 in Fig. 9B and Fig. 9C is normalized according to the normal state distribution.

[0056] (2.2.3) Prediction section The prediction unit 13 predicts an abnormality (failure) in the mounting quality based on the judgment result of the judgment unit 12. Here, the abnormality in the mounting quality occurs when the mounting position deviation amount of a specific second object T2, of the multiple second objects T2 mounted on the first object T1, whose mounting position deviation amount exceeds the first judgment range R1, exceeds the second judgment range R2. In other words, before the abnormality in the mounting quality occurs, the mounting quality changes. Therefore, the prediction unit 13 predicts the abnormality in the mounting quality based on the first information D1 from the post-mounting inspection system 25. That is, the step (process) in which the prediction unit 13 predicts the abnormality in the mounting quality is the prediction step. For example, when the judgment unit 12 judges that the mounting position deviation amount of the second object T2 has changed in a direction exceeding the second judgment range R2, the prediction unit 13 predicts that the mounting quality will become abnormal (failure).

[0057] Furthermore, in the prediction step, the prediction unit 13 predicts at least the time until an abnormality occurs in the board manufacturing line 2. Specifically, the prediction unit 13 stores, for example, the time until the mounting position deviation amount of the second object T2 becomes an outlier Ou1 (or Ou2) exceeding the first judgment range R1 from an initial position within the first judgment range R1 (exceeding the first judgment range R1 in FIG. 7), and predicts the time until the outliers Ou1, Ou2 exceed the second judgment range R2 based on this time. In this way, according to the quality change detection method and quality change detection system 1 of this embodiment, it is possible to predict the time until an abnormality occurs in the mounting quality.

[0058] The prediction unit 13 may predict the probability of abnormality occurring in the mounting quality after a predetermined time has elapsed, the number of abnormality occurrences, etc. Alternatively, the prediction unit 13 may predict the probability of abnormality occurrence, the number of abnormality occurrences, etc. per production number or per production lot.

[0059] (2.2.4) Factor Estimation Section The factor estimation unit 14 estimates the malfunction part in the board manufacturing line 2 that is the cause of the change in the mounting quality based on the information on the mounting position deviation amount. The estimation step is a step (process) in which the factor estimation unit 14 estimates the malfunction part in the board manufacturing line 2 that is the cause of the change in the mounting quality. For example, when the determination unit 12 determines that the mounting position deviation amount of the second object T2 has changed in a direction exceeding the first determination range R1, information on the fluctuation of the correction amount (recognition correction amount) of the mounting position of the specific second object T2 calculated based on the image pickup result by the component recognition camera 222 described later is called from the second information D2 from the mounting system 22. If there is a correlation between the change in the mounting position deviation amount in a direction exceeding the first determination range R1 and the fluctuation of the recognition correction amount, it is estimated that the change in the mounting quality is caused by a malfunction in the pickup process. Alternatively, if the change in the mounting position deviation amount in a direction exceeding the first determination range R1 occurs when the second object T2 is supplied from a specific feeder, it is estimated that the change in the mounting quality is caused by a malfunction of the specific feeder. That is, the cause estimation unit 14 estimates the malfunction location using, in addition to the first information D1 from the post-mounting inspection system 25, second information D2 from the mounting system 22, which is information corresponding to the amount of mounting position deviation and is equipment 4 used when mounting the second object T2 on the first object T1.

[0060] It should be noted that the malfunction locations estimated by the cause estimation unit 14 are not limited to units that constitute the equipment 4, such as feeders, heads, and nozzles, but also include processes such as the suction process and the printing process, and the equipment 4 that constitutes the board manufacturing line 2.

[0061] Furthermore, the cause estimation unit 14 may estimate the downtime (operational time loss) due to a breakdown in the feeder, head, or nozzle that is the estimated malfunctioning part, and the appropriate timing for maintenance of the malfunctioning part.

[0062] (2.2.5) Creation Department The creation unit 15 creates a normal state distribution from the mounting position deviation amounts that have been judged to have normal mounting quality (i.e., within the second judgment range R2) after a past mounting process. The normal state distribution is created for each combination of the type of the second object T2 to be detected and the mounting angle. For example, when a resistor of 0603 size and a resistor of 1005 size are detected, a normal state distribution is created from the mounting position deviation amounts corresponding to the resistor of 0603 size and the mounting position deviation amounts corresponding to the resistor of 1005 size, respectively. The first judgment range R1 is calculated from the standard deviation of the normal state distribution. When there is a normal state distribution corresponding to the second object T2 to be detected, information on the first judgment range R1, average, and variance calculated from the normal state distribution is output to the judgment unit 12. It is preferable that the number of data on the mounting position deviation amounts is large in order to ensure the accuracy of the normal state distribution. Therefore, data on the mounting position deviation amounts is collected across multiple production lots. As an example, the number of data on the mounting position deviation amounts is 8000 points on average. The normal state distribution may be updated when a sufficient amount of data on the amount of mounting position misalignment is collected. For example, the normal state distribution may be updated at a predetermined interval when a certain amount of data on the amount of mounting position misalignment for each type of component is accumulated, for example, once a day, and the update timing may be set appropriately.

[0063] (2.2.6) Notification section The notification unit 16 notifies at least one of the judgment result of the judgment unit 12 and the prediction result of the prediction unit 13 to, for example, a manager (worker) of a factory. In this embodiment, the notification unit 16 notifies the worker of the judgment result in the first judgment step of the judgment unit 12, the judgment result in the second judgment step of the judgment unit 12, and the prediction result of the prediction unit 13. For example, when the judgment unit 12 judges that the mounting position deviation amount is approaching the threshold value (TH11, TH12) of the first judgment range R1, the notification unit 16 notifies the worker that the mounting quality has changed, and when the judgment unit 12 judges that the mounting position deviation amount cannot be regarded as equivalent to the normal state distribution based on the statistical information (average and variance) calculated from the distribution of the mounting position deviation amount included in the first judgment range R1, the notification unit 16 notifies the worker that the mounting quality has changed. In addition, when the prediction unit 13 predicts that the mounting quality will become abnormal (defective), the notification unit 16 notifies the worker that an abnormality (defect) will occur in the mounting quality. Here, the manner of notification by the notification unit 16 includes, for example, display or lighting on the display unit (liquid crystal display or light emitting unit) of the equipment 4, transmission of data to a terminal (personal computer, tablet, smartphone, etc.) used by an operator, display, audio output, recording (writing) to a non-transitory recording medium, and printing (printing out), etc. The notification unit 16 may notify any one of the judgment result in the first judgment step of the judgment unit 12, the judgment result in the second judgment step, and the prediction result of the prediction unit 13.

[0064] (2.3) Implementation System Next, the configuration of the mounting system 22 according to this embodiment will be described with reference to FIGS.

[0065] As shown in Figures 2, 3 and 5, the mounting system 22 of this embodiment includes a mounting head 221, a component recognition camera 222, a control device 223, a driving device 224, a component supply device 225, and a conveying device 226.

[0066] (2.3.1) Mounting Head The mounting head 221 has at least one capturing portion 2211. In this embodiment, the mounting head 221 has a plurality of capturing portions 2211. The mounting head 221 moves the capturing portion 2211 so as to approach the first object T1 (substrate 100) in a state in which the second object T2 (component 200) is captured by the capturing portion 2211, and mounts the second object T2 on the mounting surface 101 of the first object T1. In other words, the mounting head 221 holds the capturing portion 2211 so as to be movable between a first position where the capturing portion 2211 is closer to the first object T1 and a second position which is farther away from the first object T1 than the first position. That is, the mounting head 221 holds the capturing portion 2211 so as to be movable toward the first object T1.

[0067] In this embodiment, in addition to the capturing portion 2211, the mounting head 221 further has an actuator 2212 (see FIG. 5) for moving the capturing portion 2211, and a head body 2213 (see FIG. 3) that holds the capturing portion 2211 and the actuator 2212. In the mounting system 22 according to this embodiment, one head body 2213 holds a plurality of capturing portions 2211 and actuators 2212. This allows the mounting head 221 to capture a plurality of second objects T2 (components 200).

[0068] The capturing unit 2211 is, for example, a suction nozzle. The capturing unit 2211 is controlled by the control device 223 and can switch between a capturing state in which the second object T2 is captured (held) and a release state in which the second object T2 is released (released from capture). However, the capturing unit 2211 is not limited to a suction nozzle that suctions the second object T2 by vacuum force, and may be configured to capture (hold) the second object T2 by, for example, a chuck mechanism or robot hand having a structure that physically pinches (pinch) the second object T2, or other configurations that suction (suck) the second object T2 by magnetic force or static electricity.

[0069] Regarding the capture of the second target T2 by the capture part 2211, the mounting head 221 operates by receiving air pressure (vacuum) as a power source. That is, the mounting head 221 switches the capture part 2211 between a capture state and a release state by opening and closing a valve on a supply path of air pressure (vacuum) connected to the capture part 2211.

[0070] The actuator 2212 moves the capturing part 2211 linearly in the Z-axis direction. Furthermore, the actuator 2212 rotates the capturing part 2211 in a rotation direction (hereinafter referred to as "θ direction") around an axis line along the Z-axis direction. In the present embodiment, as an example, the actuator 2212 drives the capturing part 2211 in the Z-axis direction by a driving force generated by a linear motor. The actuator 2212 drives the capturing part 2211 in the θ direction by a driving force generated by a rotary motor. On the other hand, as described later, the mounting head 221 moves linearly in the X-axis direction and the Y-axis direction by the driving device 224. As a result, the capturing part 2211 included in the mounting head 221 can move in the X-axis direction, the Y-axis direction, the Z-axis direction, and the θ direction by the driving device 224 and the actuator 2212.

[0071] The head body 2213 is made of metal and formed into a rectangular parallelepiped shape, for example. The capturing portion 2211 and the actuator 2212 are assembled to the head body 2213, whereby the head body 2213 holds the capturing portion 2211 and the actuator 2212. In this embodiment, the capturing portion 2211 is indirectly held by the head body 2213 via the actuator 2212 in a state in which the capturing portion 2211 is movable in the Z-axis direction and the θ direction. The mounting head 221 moves within the XY plane as the head body 2213 is moved within the XY plane by the driving device 224.

[0072] According to the above-mentioned configuration, the mounting head 221, in a state in which the capturing portion 2211 has captured the second object T2 (component 200), moves the capturing portion 2211 so as to approach the first object T1 (substrate 100), and can mount the second object T2 on the mounting surface 101 of the first object T1. That is, the mounting head 221 moves the capturing portion 2211 at least between a first position that is closer to the first object T1 and a second position that is farther away from the first object T1 than the first position. In short, the mounting head 221 moves the capturing portion 2211, in a state in which the second object T2 has been captured, from the second position to the first position, thereby mounting the second object T2 on the mounting surface 101 of the first object T1.

[0073] In this embodiment, the mounting head 221 further includes a head camera 2214 in addition to the capture unit 2211, the actuator 2212, and the head body 2213. The head camera 2214 is fixed to the mounting head 221 by being fixed to the side of the head body 2213. In this embodiment, the mounting system 22 includes one head camera 2214. The head camera 2214 is, for example, an area camera. In this embodiment, the head camera 2214 is disposed with its imaging field of view facing downward, and images a board mark for positioning attached to the first object T1. The head camera 2214 may also image a specific area including a joining member (for example, solder) of the mounting surface 101 of the first object T1 (board 100).

[0074] (2.3.2) Part Recognition Camera The component recognition camera 222 is disposed on the base 220 of the mounting system 22 with its imaging field of view facing upward. The component recognition camera 222 captures an image of the underside of the component 200 held by the capture unit 2211 of the mounting head 221 from below. Based on the captured image, the control device 223 (described later) calculates the amount of positional deviation of the component 200 with respect to the capture unit 2211 of the mounting head 221, and corrects the mounting position of the component 200 on the board 100 by the mounting head 221 based on the calculated amount of positional deviation. Note that in this embodiment, the component recognition camera 222 is disposed on the base 220 of the mounting system 22, but is not limited thereto, and may be provided integrally with the mounting head 221, for example.

[0075] (2.3.3) Control device The control device 223 controls each part of the mounting system 22. The control device 223 is mainly configured as a computer system having one or more processors and one or more memories. That is, the functions of the control device 223 are realized by one or more processors executing a program recorded in one or more memories of the computer system. The program may be recorded in the memory in advance, may be provided via a telecommunication line such as the Internet, or may be provided by recording it on a non-transitory recording medium such as a memory card.

[0076] The control device 223 is electrically connected to, for example, each of the mounting head 221, the head camera 2214, the component recognition camera 222, the drive device 224, the component supply device 225, and the transport device 226. The control device 223 outputs a control signal to the mounting head 221 and the drive device 224, and controls the mounting head 221 and the drive device 224 so as to mount at least the second object T2 captured by the capture unit 2211 on the mounting surface 101 of the first object T1. The control device 223 also outputs a control signal to the head camera 2214 and the component recognition camera 222 to control the head camera 2214 and the component recognition camera 222, and acquires images captured by the head camera 2214 and the component recognition camera 222 from the head camera 2214 and the component recognition camera 222.

[0077] (2.3.4) Driving device The driving device 224 is a device that moves the mounting head 221. In this embodiment, the driving device 224 moves the mounting head 221 in the XY plane. The "XY plane" here is a plane that includes the X axis and the Y axis and is perpendicular to the Z axis. In other words, the driving device 224 moves the mounting head 221 in the X-axis direction and the Y-axis direction. In this embodiment, since the head camera 2214 is fixed to the mounting head 221, the driving device 224 also moves the head camera 2214 together with the mounting head 221. In other words, the driving device 224 moves the mounting head 221 and the head camera 2214 in the XY plane.

[0078] Specifically, as shown in Fig. 2 and Fig. 3, the driving device 224 has an X-axis driving unit 2241 and a Y-axis driving unit 2242. The X-axis driving unit 2241 moves the mounting head 221 linearly in the X-axis direction. The Y-axis driving unit 2242 moves the mounting head 221 linearly in the Y-axis direction. The Y-axis driving unit 2242 moves the mounting head 221 linearly in the Y-axis direction by moving the mounting head 221 together with the X-axis driving unit 2241 along the Y-axis. In the present embodiment, as an example, each of the X-axis driving unit 2241 and the Y-axis driving unit 2242 includes a linear motor, and moves the mounting head 221 by a driving force generated by the linear motor upon receiving power supply.

[0079] (2.3.5) Parts supply device The component supplying device 225 supplies components 200 as second objects T2 to be captured by the capturing unit 2211 of the mounting head 221. As an example, the component supplying device 225 has a plurality of tape feeders 2251 that supply the components 200 accommodated in a carrier tape 6. Alternatively, the component supplying device 225 may have a tray on which a plurality of components 200 are placed. The mounting head 221 captures the second objects T2 (components 200) from such a component supplying device 225 by the capturing unit 2211.

[0080] (2.3.6) Conveyor The transport device 226 is a device that transports the board 100 as the first object T1. The transport device 226 is realized by, for example, a belt conveyor. The transport device 226 transports the first object T1 (board 100), for example, along the X-axis. The transport device 226 transports the first object T1 at least below the mounting head 221, that is, to a mounting space that faces the capture unit 2211 in the Z-axis direction. Then, the transport device 226 stops the first object T1 in the mounting space until the mounting head 221 completes mounting the second object T2 (component 200) on the first object T1 (board 100).

[0081] (2.3.7) Other In addition to the above configuration, the mounting system 22 also includes, for example, a communication unit etc. The communication unit is configured to communicate with a higher-level system directly or indirectly via a network or a repeater etc. This allows the mounting system 22 to transmit and receive data to and from the higher-level system.

[0082] (2.4) Inspection system Next, the post-mounting inspection system 25 will be described.

[0083] As described above, the post-mounting inspection system 25 is a system for inspecting the mounting state of the second object T2 relative to the first object T1 in the second inspection process between the mounting process and the reflow process. As shown in Fig. 4, the post-mounting inspection system 25 is connected to the quality change detection system 1 via the management computer 3, and outputs first information D1 to the quality change detection system 1. As described above, the first information D1 includes the amount of mounting position deviation of the second object T2 relative to the first object T1 before the reflow process.

[0084] The post-mounting inspection system 25 calculates the amount of mounting positional deviation of all the second objects T2 mounted on the first object T1. Specifically, the post-mounting inspection system 25 calculates the difference between the actual mounting position of the second object T2 with respect to the first object T1 and the target mounting position of the second object T2 with respect to the first object T1 as the amount of mounting positional deviation.

[0085] (3) Operation Next, the quality change detection method according to this embodiment will be described with reference to FIG.

[0086] The acquisition unit 11 acquires the first information D1 from the post-mounting inspection system 25 and the second information D2 from the mounting system 22 at the timing when the production of a preset number of boards 100 (first objects T1) is completed. Then, the acquisition unit 11 groups (classifies) the first information D1 acquired from the post-mounting inspection system 25 by type of the second objects T2 and by mounting angle of the second objects T2 with respect to the first objects T1, and outputs the grouped information to the determination unit 12. Here, the "timing when production is completed" may be the timing when all the processes of production of the boards 100 in the board manufacturing line 2 are completed, or may be the timing when inspection by the post-mounting inspection system 25 is completed.

[0087] When the first information D1 is input from the acquisition unit 11, the determination unit 12 executes outlier detection F1 (steps ST1 to ST3). In the outlier detection F1, the determination unit 12 compares the absolute value of the mounting position deviation amount GapX of each second object T2 mounted on the first object T1 with the comparison value 3σ (step ST1). Here, "σ" in the comparison value 3σ is the standard deviation of the normal state distribution described above, and the comparison value 3σ is a value that defines the first determination range R1. That is, the first determination range R1 is a range defined by the comparison value +3σ and the comparison value -3σ. The comparison value is set for each category, and in this embodiment, the determination unit 12 makes a determination based on the comparison value set for each type of component 200 and each mounting angle. When the absolute value of the mounting position deviation amount GapX is smaller than the comparison value 3σ (step ST1: Yes), the determination unit 12 temporarily stores data of the mounting position deviation amount GapX in the buffer memory (step ST2). On the other hand, if the absolute value of the mounting position misalignment amount GapX is 3σ or more (step ST1: No), the determination unit 12 records the determination result that the mounting position misalignment amount GapX is an outlier (step ST3). The determination unit 12 executes outlier detection F1 for all second objects T2 mounted on the first object T1 (steps ST1 to ST3).

[0088] The determination unit 12 compares the number of data of the mounting position deviation amount GapX stored in the buffer memory with a preset threshold value (minimum number of data for determination) (step ST4). If the number of data is equal to or greater than the threshold value (step ST4: Yes), the determination unit 12 executes distribution change detection F2 (steps ST5 to ST9). Specifically, in the distribution change detection F2, the determination unit 12 determines whether the distribution of the mounting position deviation amount GapX stored in the buffer memory and the normal state distribution created in advance by the creation unit 15 are equal variances based on the variance calculated from the distribution (step ST5). The term "equal variances" used here includes not only the case where the two variances are completely equal, but also the case where the ratio of the two variances is within a certain range. As described above, the normal state distribution is obtained from the past first information D1.

[0089] If the distribution of the mounting position deviation amount GapX and the normal state distribution are not equal in variance (step ST5: No), that is, if the variance of the distribution of the mounting position deviation amount GapX has changed in a direction in which it is larger than the normal state distribution, the determination unit 12 records the determination result that the mounting position deviation amount GapX of the second object T2 has changed in a direction exceeding the first determination range R1 (step ST6). Furthermore, the determination unit 12 determines whether the average value of the distribution of the mounting position deviation amount GapX and the average value of the normal state distribution are equal in average (step ST7). Here, "equal averages" includes not only the case where the average values ​​of the two are completely equal, but also the case where the ratio of the average values ​​of the two is within a certain range.

[0090] If the two average values ​​are not equal (step ST7: No), the determination unit 12 records the determination result that the mounting position misalignment amount GapX of the second object T2 has changed in a direction exceeding the first determination range R1 (step ST8). On the other hand, if the two average values ​​are equal (step ST7: Yes), the determination unit 12 determines that the mounting position misalignment amount GapX of each second object T2 is within the normal range (i.e., a range not exceeding the second determination range R2), and resets (deletes) the data of the mounting position misalignment amount GapX stored in the buffer memory (step ST9).

[0091] On the other hand, if the number of data is less than the threshold (step ST4: No), and if data to be judged remains (step ST10: Yes), the judgment unit 12 executes the above-mentioned outlier detection F1 and distribution change detection F2. On the other hand, if no data to be judged remains (step ST10: No), the judgment unit 12 ends the series of processes. In this embodiment, the step in which the acquisition unit 11 acquires the first information D1 is the acquisition step, and the above-mentioned steps ST1 to ST9 are the judgment steps.

[0092] In this way, in the quality change detection method and quality change detection system 1 according to the present embodiment, as described above, even if the mounting position deviation amount GapX of the second object T2 is within the second judgment range R2 in which the mounting quality is judged to be normal, if it exceeds the first judgment range R1 or if it has changed in a direction that exceeds the first judgment range R1, it is judged that the mounting quality has changed. Therefore, it is possible to know that the mounting quality has changed in a direction that becomes abnormal before the mounting position deviation amount GapX exceeds the second judgment range R2. This makes it possible to prevent the occurrence of mounting defects of the second object T2 on the first object T1.

[0093] (4) Variations The above-described embodiment is merely one of various embodiments of the present disclosure. The above-described embodiment can be modified in various ways depending on the design, etc., as long as the object of the present disclosure can be achieved. Furthermore, functions similar to the quality change detection method according to the above-described embodiment may be embodied in a quality change detection system 1, a (computer) program, or a non-transitory recording medium having a program recorded thereon, etc. A program according to one aspect is a program for causing one or more processors to execute the quality change detection method according to the above-described embodiment.

[0094] Modifications of the above-described embodiment are listed below. The modifications described below can be applied in appropriate combination.

[0095] The quality change detection system 1 in the present disclosure includes a computer system. The computer system is mainly composed of a processor and a memory as hardware. The processor executes a program recorded in the memory of the computer system to realize the function of the quality change detection system 1 in the present disclosure. The program may be pre-recorded in the memory of the computer system, provided through an electric communication line, or provided by recording it in a non-transitory recording medium such as a memory card, an optical disk, or a hard disk drive that can be read by the computer system. The processor of the computer system is composed of one or more electronic circuits including a semiconductor integrated circuit (IC) or a large-scale integrated circuit (LSI). The integrated circuits such as IC or LSI referred to here are called by different names depending on the degree of integration, and include integrated circuits called system LSI, VLSI (Very Large Scale Integration), or ULSI (Ultra Large Scale Integration). Furthermore, a field-programmable gate array (FPGA) that is programmed after the manufacture of the LSI, or a logic device that can reconfigure the connection relationship inside the LSI or the circuit partition inside the LSI, can also be adopted as a processor. The electronic circuits may be integrated in one chip or distributed among multiple chips. The chips may be integrated in one device or distributed among multiple devices. The computer system referred to here includes a microcontroller having one or more processors and one or more memories. Thus, the microcontroller is also composed of one or more electronic circuits including a semiconductor integrated circuit or a large-scale integrated circuit.

[0096] Furthermore, it is not essential for quality change detection system 1 that multiple functions are concentrated in one housing. The components of quality change detection system 1 may be distributed across multiple housings. Furthermore, at least some of the functions of quality change detection system 1 may be realized by the cloud (cloud computing) or the like.

[0097] In the mounting process, one mounting system 22 may be used for the task of mounting the second object T2 on the first object T1, or multiple mounting systems 22 (22A, 22B in FIG. 1) may be used.

[0098] In the above embodiment, the mounting quality is the quality when mounting the second object T2 on the first object T1 and includes the mounting position (or mounting angle), but it may be the quality when capturing the second object T2 from the component supply device 225. In other words, the mounting quality may include the position of the suction nozzle 2211 with respect to the second object T2.

[0099] In the above-described embodiment, the quality change detection method and the quality change detection system 1 are used for mounting misalignment in the mounting process, but for example, the quality change detection method and the quality change detection system 1 may be used for application misalignment in the solder application process. In this case, the acquisition unit 11 acquires the amount of positional misalignment between the position of the solder applied (printed) on the first object T1 and the position of the land from the post-printing inspection system 24.

[0100] Furthermore, in the above embodiment, the facility 4 is the mounting system 22, but the facility 4 is not limited to the mounting system 22 and may be, for example, the printing system 21. In this case, the first judgment range R1 may be set depending on the type of cream solder.

[0101] In the above embodiment, notification unit 16 notifies the worker of both the determination result of determination unit 12 and the prediction result of prediction unit 13, but notification unit 16 may notify the worker of only the determination result of determination unit 12, or may notify the worker of only the prediction result of prediction unit 13. Furthermore, notification unit 16 is not limited to notifying the worker, and may also notify a robot that performs maintenance work on board production line 2 including equipment 4 on behalf of the worker.

[0102] In the above embodiment, the comparison value of the mounting position misalignment amount GapX of the second object T2 is 3σ as shown in FIG. 10, but the comparison value may be, for example, 2σ or 1σ.

[0103] In the above embodiment, the determination unit 12 executes the distribution change detection F2 when the number of the second objects T2 that are not outliers detected in the outlier detection F1 is equal to or more than a certain number, as shown in FIG. 10. The determination unit 12 may execute the distribution change detection F2 in either the case where an outlier is not detected in the outlier detection F1 or the case where an outlier is detected. The determination unit 12 may determine that the mounting quality has changed based on the statistical information regarding the mounting position deviation amount GapX of the second object T2 even when the mounting position deviation amount GapX of all the second objects T2 is included in the first determination range R1. Even in this case, the determination unit 12 can determine that the mounting position deviation amount GapX of the second object T2 has changed in a direction exceeding the first determination range R1 by not having equal variance or equal average.

[0104] In the above embodiment, the first judgment range R1 (range based on the standard deviation of the normal state distribution) is set for each type of the second object T2 and for each mounting angle of the second object T2 relative to the first object T1, but is not limited thereto. For example, when the first judgment range R1 is set for each type of the second object T2, the same first judgment range R1 may be applied even if the mounting angle of the second object T2 relative to the first object T1 is different. Also, when the first judgment range R1 is set for each mounting angle of the second object T2 relative to the first object T1, the same first judgment range R1 may be applied even if the type of the second object T2 is different. Also, the first judgment range R1 may be applied for each unit (feeder or nozzle) used to mount the second object T2.

[0105] In the above embodiment, as shown in FIG. 8, the center of the first judgment range R1 and the center of the second judgment range R2 are coincident, and the first judgment range R1 and the second judgment range R2 are concentric. In contrast, the first judgment range R1 may be included in the second judgment range R2, and the center of the first judgment range R1 and the center of the second judgment range R2 may be shifted. In the above embodiment, the shape of each of the first judgment range R1 and the second judgment range R2 is a circle, but the shape of each of the first judgment range R1 and the second judgment range R2 may be, for example, an ellipse or a polygon (for example, a rectangle). Furthermore, the shape of each of the first judgment range R1 and the second judgment range R2 may be the same or different. In addition, as shown in FIG. 9A to FIG. 9C, the average of the first judgment range R1 is not necessarily zero.

[0106] In the above embodiment, the first information D1 is information acquired in the second inspection process, but is not limited thereto. The first information may be information acquired in the third inspection process, or may include both information acquired in the second inspection process and information acquired in the third inspection process.

[0107] (summary) As described above, the quality change detection method according to the first aspect includes an acquisition step and a first determination step. The acquisition step is a step of acquiring a mounting position deviation amount, which is a difference between an actual mounting position of a second object (T2) relative to a first object (T1) and a target mounting position. The first determination step is a step of determining that the mounting quality has changed when the mounting position deviation amount acquired in the acquisition step exceeds a first determination range (R1) and falls within a second determination range (R2). The first determination range (R1) is included in a second determination range (R2) in which the mounting quality is determined to be normal.

[0108] According to this embodiment, it is possible to prevent the occurrence of defective mounting of the second object (T2) on the first object (T1).

[0109] The quality change detection method according to the second aspect is the same as the first aspect, but further includes a second determination step of determining that the mounting quality has changed based on statistical information regarding the mounting position deviation amount included in the first determination range (R1).

[0110] According to this embodiment, it is possible to prevent the occurrence of defective mounting of the second object (T2) on the first object (T1).

[0111] In a quality change detection method according to a third aspect, in the second aspect, the statistical information includes at least one of an average calculated from the distribution of the mounting position misalignment amounts and a variance calculated from the distribution of the mounting position misalignment amounts.

[0112] In the quality change detection method according to the fourth aspect, in the second or third aspect, when the number of second objects (T2) whose mounting position misalignment amount falls within the first judgment range (R1) reaches a certain number or more, a second judgment step is executed.

[0113] According to this embodiment, it is possible to prevent the occurrence of defective mounting of the second object (T2) on the first object (T1).

[0114] In the quality change detection method according to the fifth aspect, in any one of the first to fourth aspects, the first judgment range (R1) is set according to the type of the second object (T2).

[0115] According to this embodiment, the first judgment range (R1) can be set according to the type of the second object (T2).

[0116] In a quality change detection method according to a sixth aspect, in any one of the first to fifth aspects, the first judgment range (R1) is set according to a mounting angle of the second object (T2) relative to the first object (T1).

[0117] According to this embodiment, the first determination range (R1) can be set according to the mounting angle of the second object (T2) relative to the first object (T1).

[0118] A mounting quality control method according to a seventh aspect is any one of the first to sixth aspects, further comprising a prediction step. The prediction step is a step of predicting an abnormality in the mounting quality based on first information (D1). The first information (D1) is information on a mounting position deviation amount.

[0119] According to this embodiment, it is possible to prevent the occurrence of defective mounting of the second object (T2) on the first object (T1).

[0120] In a quality change detection method according to an eighth aspect, in the seventh aspect, the predicting step predicts a time until an abnormality occurs in at least the quality of the mounting.

[0121] According to this aspect, it is possible to predict the time until an abnormality in the mounting quality occurs.

[0122] The quality change detection method according to a ninth aspect is the seventh or eighth aspect, further comprising a notification step. The notification step is a step of notifying at least one of a plurality of results including the determination result of the first determination step and the prediction result of the prediction step.

[0123] According to this aspect, at least one of a plurality of results can be notified.

[0124] The quality change detection method according to a tenth aspect is any one of the first to ninth aspects, further comprising an estimation step of estimating a malfunction location in the mounting system (22) that is the cause of the change in mounting quality, based on first information (D1) related to the mounting position deviation amount.

[0125] According to this embodiment, the location of the malfunction in the mounting system (22) can be estimated.

[0126] In the quality change detection method according to the eleventh aspect, in the tenth aspect, in addition to the first information (D1), the estimation step uses second information (D2). The second information (D2) is information corresponding to the mounting position deviation amount, and is information about the equipment (4) used when mounting the second object (T2) on the first object (T1).

[0127] According to this embodiment, it is possible to prevent the occurrence of defective mounting of the second object (T2) on the first object (T1).

[0128] In the quality change detection method according to the 12th aspect, in any one of the first to 11th aspects, the first object (T1) is a component (200), and the second object (T2) is a board (100) on which the component (200) is mounted.

[0129] According to this embodiment, it is possible to prevent the occurrence of defective mounting of the component (200) on the substrate (100).

[0130] A quality change detection system (1) according to a thirteenth aspect includes an acquisition unit (11) and a judgment unit (12). The acquisition unit (11) acquires a mounting position deviation amount, which is a difference between an actual mounting position of a second object (T2) relative to a first object (T1) and a target mounting position. The judgment unit (12) judges that the mounting quality has changed when the mounting position deviation amount acquired by the acquisition unit (11) exceeds a first judgment range (R1) and falls within a second judgment range (R2). The first judgment range (R1) is included in a second judgment range (R2) in which the mounting quality is judged to be normal.

[0131] According to this embodiment, it is possible to prevent the occurrence of defective mounting of the second object (T2) on the first object (T1).

[0132] A program according to a fourteenth aspect is a program for causing one or more processors to execute the quality change detection method according to any one of the first to twelfth aspects.

[0133] According to this embodiment, it is possible to prevent the occurrence of defective mounting of the second object (T2) on the first object (T1).

[0134] The configurations according to the second to twelfth aspects are not essential to the quality change detection method and may be omitted as appropriate. [Explanation of symbols]

[0135] 1. Quality change detection system 4 Equipment 11 Acquisition Department 12 Judgment section 100 Substrates 200 parts D1 First Information D2 2nd information R1 First judgment range R2 Second judgment range T1 First Object T2 Second Object

Claims

1. an acquiring step of acquiring a mounting position deviation amount which is a difference between an actual mounting position of a second object with respect to a first object and a target mounting position; a first determination step of determining that a quality of mounting has changed when the mounting position deviation amount acquired in the acquisition step exceeds a first determination range and is within a second determination range, the first determination range is included in the second determination range in which the mounting quality is determined to be normal; a second determination step of determining that the mounting quality has changed based on statistical information regarding the mounting position deviation amount included in the first determination range. Quality change detection method.

2. The statistical information is an average calculated from the distribution of the mounting position deviation amounts; and a variance calculated from the distribution of the mounting position deviation amount. The quality change detection method according to claim 1 .

3. When a certain number or more of the second objects are collected, the second judgment step is executed. The quality change detection method according to claim 1 or 2.

4. An acquisition step of acquiring a mounting position deviation amount, which is a difference between an actual mounting position of a second object relative to a first object and a target mounting position; a first determination step of determining that a quality of mounting has changed when the mounting position deviation amount acquired in the acquisition step exceeds a first determination range and is within a second determination range, the first determination range is included in the second determination range in which the mounting quality is determined to be normal; the first determination range is set according to a mounting angle of the second object relative to the first object. Quality change detection method.

5. An acquisition step of acquiring a mounting position deviation amount which is a difference between an actual mounting position of a second object relative to a first object and a target mounting position; a first determination step of determining that a quality of mounting has changed when the mounting position deviation amount acquired in the acquisition step exceeds a first determination range and is within a second determination range, the first determination range is included in the second determination range in which the mounting quality is determined to be normal; The method further includes a prediction step of predicting an abnormality in the mounting quality based on the first information on the mounting position deviation amount. Quality change detection method.

6. In the prediction step, a time until an abnormality in the quality of the mounting is generated is predicted. The quality change detection method according to claim 5.

7. The method further comprises a notification step of notifying at least one of a plurality of results including a judgment result of the first judgment step and a prediction result of the prediction step. The quality change detection method according to claim 5 or 6.

8. An acquisition step of acquiring a mounting position deviation amount which is a difference between an actual mounting position of a second object relative to a first object and a target mounting position; a first determination step of determining that a quality of mounting has changed when the mounting position deviation amount acquired in the acquisition step exceeds a first determination range and is within a second determination range, the first determination range is included in the second determination range in which the mounting quality is determined to be normal; The method further includes an estimation step of estimating a malfunction location in the mounting system that is a cause of the change in the mounting quality based on the first information on the mounting position deviation amount, In the estimation step, in addition to the first information, second information is used, which is information corresponding to the mounting position deviation amount and is related to equipment used when mounting the second object on the first object. Quality change detection method.

9. The first judgment range is set according to the type of the second object. The quality change detection method according to any one of claims 1 to 8.

10. The first object is a part, The second object is a substrate on which the component is mounted. The quality change detection method according to any one of claims 1 to 9.

11. An acquisition unit that acquires a mounting position deviation amount, which is a difference between an actual mounting position of a second object relative to a first object and a target mounting position; a determination unit that determines that a quality of mounting has changed when the mounting position deviation amount acquired by the acquisition unit exceeds a first determination range and falls within a second determination range, the first determination range is included in the second determination range in which the mounting quality is determined to be normal; a second determination unit that determines that the mounting quality has changed based on statistical information regarding the mounting position deviation amount included in the first determination range. Quality change detection system.

12. An acquisition unit that acquires a mounting position deviation amount, which is a difference between an actual mounting position of a second object relative to a first object and a target mounting position; a determination unit that determines that a quality of mounting has changed when the mounting position deviation amount acquired by the acquisition unit exceeds a first determination range and falls within a second determination range, the first determination range is included in the second determination range in which the mounting quality is determined to be normal; the first determination range is set according to a mounting angle of the second object relative to the first object. Quality change detection system.

13. an acquisition unit that acquires a mounting position deviation amount that is a difference between an actual mounting position of a second object relative to a first object and a target mounting position; a determination unit that determines that a quality of mounting has changed when the mounting position deviation amount acquired by the acquisition unit exceeds a first determination range and falls within a second determination range, the first determination range is included in the second determination range in which the mounting quality is determined to be normal; a prediction unit that predicts an abnormality in the quality of the mounting based on the first information on the amount of mounting position deviation, Quality change detection system.

14. An acquisition unit that acquires a mounting position deviation amount, which is a difference between an actual mounting position of a second object relative to a first object and a target mounting position; a determination unit that determines that a quality of mounting has changed when the mounting position deviation amount acquired by the acquisition unit exceeds a first determination range and falls within a second determination range, the first determination range is included in the second determination range in which the mounting quality is determined to be normal; an estimation unit that estimates a malfunction location in the mounting system that is a cause of the change in mounting quality based on the first information on the mounting position deviation amount, the estimation unit uses, in addition to the first information, second information corresponding to the mounting position deviation amount and related to equipment used when mounting the second object on the first object; Quality change detection system.

15. A program for causing one or more processors to execute the quality change detection method described in any one of claims 1 to 10.

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