Apparatus, method, and recording medium for imaging printed circuit board

Abstract

The present disclosure proposes an apparatus for controlling the imaging height of an image sensor for imaging a printed circuit board. The apparatus according to the present disclosure may comprise: a conveyor belt on which a target printed circuit board is disposed; a light source radiating one or more first patterned lights to an inspection area and an inspection reference surface of the target printed circuit board as the target printed circuit board reaches an inspection position; an image sensor capturing one or more first reflected lights to acquire one or more first images; and one or more processors. The one or more processors may: determine, on the basis of the one or more first images, a first distance representing a height difference between the inspection area and the inspection reference surface; determine a height offset value for imaging the target printed circuit board on the basis of the first distance; and control the imaging height of the image sensor according to the height offset value.

Description

Device, method, and recording medium for imaging a printed circuit board

[0001] The present disclosure relates to a technology for imaging a printed circuit board.

[0002] Before mounting components on a printed circuit board, a solder printing device (e.g., a screen printer) can apply solder onto the pads of the board. Afterward, a solder paste inspection (SPI) device can photograph and inspect the condition of the applied solder.

[0003] In addition, components can be mounted on the pads of a printed circuit board coated with solder using Surface Mount Technology (SMT), and the mounted components can be imaged and inspected.

[0004] In a process of forming a printed circuit board and an object to be inspected (e.g., solder, components, dies, etc.) within the printed circuit board, various inspections may be performed to determine whether the process has been properly carried out. When performing such inspections, it may be necessary to image the printed circuit board to verify whether the printed circuit board is properly positioned within the equipment or to determine the three-dimensional shape of the object to be inspected.

[0005] The present disclosure provides a technology for imaging a printed circuit board.

[0006] The present disclosure proposes an apparatus for controlling the imaging height of an image sensor for imaging a printed circuit board. The apparatus according to the present disclosure comprises: a conveyor belt on which a target printed circuit board is placed and which moves the target printed circuit board to an inspection position; a light source that irradiates one or more first pattern lights onto an inspection area and an inspection reference plane of the target printed circuit board as the target printed circuit board reaches the inspection position; an image sensor that acquires one or more first images by capturing one or more first reflected lights generated by the one or more first pattern lights being reflected from the inspection area and the inspection reference plane; and one or more processors. The apparatus may include one or more memories in which instructions to be executed by one or more processors are stored, and when the instructions are executed, the one or more processors may be configured to determine a first distance representing a height difference between an inspection area and an inspection reference plane based on one or more first images, determine a height offset value representing a vertical distance between an upper surface of a target printed circuit board and an image sensor for imaging the target printed circuit board based on the first distance, and control the imaging height of the image sensor according to the height offset value.

[0007] In one embodiment, the inspection reference surface may have a preset height difference from the upper surface of the conveyor rail supporting the conveyor belt.

[0008] In one embodiment, the inspection reference surface may be located between a first conveyor rail located below the initial position where the target printed circuit board is placed and a second conveyor rail connected to a clamp for fixing the printed circuit board.

[0009] In one embodiment, the one or more processors move the conveyor belt in a first axis direction by a distance from the initial position to the inspection position, and the first axis may represent an axis parallel to the direction of movement of the conveyor belt.

[0010] In one embodiment, the initial imaging height of the image sensor may be set to a first height focused on the upper surface of a calibration jig placed on the conveyor rail when the conveyor belt is removed from the conveyor rail.

[0011] In one embodiment, the one or more processors can set the inspection position such that, with respect to the inspection reference plane, the distance from the inspection reference plane to the inspection position is less than or equal to the first axis length of the observation area where the image sensor can capture images at the first height.

[0012] In one embodiment, the light source irradiates one or more second pattern lights onto at least a portion of the upper surface of the calibration jig and the inspection reference surface, and the one or more processors can determine a second distance representing a height difference between the upper surface of the calibration jig and the inspection reference surface based on one or more second images in which the one or more second pattern lights are reflected from at least a portion of the upper surface of the calibration jig and the inspection reference surface and one or more second reflected lights generated.

[0013] In one embodiment, the one or more processors may determine the height offset value based on the first distance and the second distance.

[0014] In one embodiment, the one or more processors can move the image sensor in a plane parallel to the upper surface of the conveyor rail so that, as the target printed circuit board reaches the inspection position, the image sensor has an observation area including the inspection area and the inspection reference plane.

[0015] In one embodiment, the target printed circuit board includes a plurality of inspection areas, and the one or more processors can individually calculate the height difference with respect to the inspection reference plane for each of the plurality of inspection areas and calculate the first distance using the average value of the calculated height differences.

[0016] In one embodiment, at least some of the plurality of inspection areas are located in a first corner area of ​​the target printed circuit board, and the remaining inspection areas, excluding at least some of the inspection areas among the plurality of inspection areas, may be located in a second corner area of ​​the target printed circuit board different from the first corner area.

[0017] In one embodiment, the one or more processors store the determined height offset value in work data of a substrate type corresponding to the target printed circuit board, and when a printed circuit board having the same substrate type as the target printed circuit board but different from the target printed circuit board is placed on the conveyor belt, the imaging height of the image sensor can be controlled according to the determined height offset value.

[0018] The present disclosure proposes a method for controlling the imaging height of an image sensor for imaging a printed circuit board. A method for inspecting a printed circuit board according to one embodiment of the present disclosure may include: driving a conveyor belt on which the target printed circuit board is placed to move the target printed circuit board to an inspection position; irradiating one or more first pattern lights onto an inspection area and an inspection reference plane of the target printed circuit board as the target printed circuit board reaches the inspection position; acquiring one or more first images by capturing one or more first reflected lights generated by the one or more first pattern lights being reflected from the inspection area and the inspection reference plane; determining a first distance representing a height difference between the inspection area and the inspection reference plane based on the one or more first images; determining a height offset value representing a vertical distance between the upper surface of the target printed circuit board and the image sensor for imaging the target printed circuit board based on the first distance; and controlling the imaging height of the image sensor according to the height offset value.

[0019] The present disclosure proposes a non-transient computer-readable recording medium that records instructions for controlling the imaging height of an image sensor for imaging a printed circuit board. Instructions recorded on the recording medium according to one embodiment of the present disclosure may be instructions to be executed by one or more processors or to be executed on a computer. The instructions may enable the one or more processors to drive a conveyor belt on which a target printed circuit board is placed to move the target printed circuit board to an inspection position, and as the target printed circuit board reaches the inspection position, to irradiate one or more first pattern lights onto an inspection area and an inspection reference plane of the target printed circuit board, and to acquire one or more first images by capturing one or more first reflected lights generated by the one or more first pattern lights being reflected from the inspection area and the inspection reference plane, and based on the one or more first images, to determine a first distance representing a height difference between the inspection area and the inspection reference plane, and based on the first distance, to determine a height offset value representing a vertical distance between the upper surface of the target printed circuit board and an image sensor for capturing the target printed circuit board, and to control the capturing height of the image sensor according to the height offset value.

[0020] According to various embodiments of the present disclosure, a printed circuit board is moved to an inspection position and then pattern light is irradiated to generate one or more images including an inspection area and an inspection reference plane of the printed circuit board, and a height offset value for imaging the printed circuit board can be determined based on the generated one or more images.

[0021] According to various embodiments of the present disclosure, the imaging height of an image sensor can be controlled according to a height offset value determined for a printed circuit board.

[0022] According to various embodiments of the present disclosure, as the printed circuit board reaches the inspection position, the position of the image sensor can be adjusted so that the image sensor has an observation area including an inspection area and an inspection reference plane of the printed circuit board.

[0023] According to various embodiments of the present disclosure, a height offset value for a printed circuit board can be determined by individually calculating the height difference from an inspection reference plane for each of the plurality of inspection areas included in the printed circuit board.

[0024] According to various embodiments of the present disclosure, a height offset value calculated for a printed circuit board is stored in work data of a substrate type corresponding to the printed circuit board, and when a substrate type identical to the printed circuit board is placed on a conveyor belt, the imaging height of an image sensor can be controlled according to the height offset value stored in the work data.

[0025] The effects according to the technical concept of the present disclosure are not limited to those mentioned above, and other unmentioned effects will be clearly understood by a person skilled in the art from the description in the specification.

[0026] FIG. 1 is a schematic diagram showing an apparatus according to one embodiment of the present disclosure.

[0027] FIG. 2 is a block diagram of a device according to one embodiment of the present disclosure.

[0028] FIGS. 3a and 3b are drawings illustrating the process of a device according to one embodiment of the present disclosure moving a target printed circuit board to an inspection position.

[0029] FIG. 4 is a drawing for explaining an inspection reference surface according to one embodiment of the present disclosure.

[0030] FIG. 5 is a diagram illustrating the process of determining the initial imaging height of an image sensor according to one embodiment of the present disclosure.

[0031] FIG. 6 is a diagram illustrating the process of a device according to one embodiment of the present disclosure determining a height offset value for imaging a target printed circuit board.

[0032] FIG. 7 is a drawing illustrating the process of a device according to one embodiment of the present disclosure adjusting the position of an imaging device (130).

[0033] FIG. 8 is a diagram illustrating the process of a device according to one embodiment of the present disclosure calculating a height offset value using a plurality of inspection areas included in a target printed circuit board.

[0034] FIG. 9 is a diagram illustrating the process of a device according to one embodiment of the present disclosure storing a height offset value for a target printed circuit board in work data.

[0035] The various embodiments described in this disclosure are illustrative for the purpose of clearly explaining the technical concept of this disclosure and are not intended to limit it to specific embodiments. The technical concept of this disclosure includes various modifications, equivalents, alternatives, and embodiments selectively combined from all or part of each embodiment described in this disclosure. Furthermore, the scope of the technical concept of this disclosure is not limited to the various embodiments presented below or the specific descriptions thereof.

[0036] Terms used in this disclosure, including technical or scientific terms, may have the meaning generally understood by those skilled in the art to which this disclosure pertains, unless otherwise defined.

[0037] Expressions used in this disclosure, such as “comprising,” “may compose,” “possessing,” “possessing,” “having,” and “possessing,” mean that the subject feature (e.g., function, operation, or component, etc.) exists and do not exclude the existence of other additional features. That is, such expressions should be understood as open-ended terms implying the possibility of including other embodiments.

[0038] Singular expressions used in this disclosure may include the meaning of the plural form unless otherwise indicated by the context, and this applies likewise to singular expressions described in the claims.

[0039] Expressions such as "first," "second," or "first," "second," etc., used in this disclosure are used to distinguish one object from another when referring to a plurality of objects of the same kind, unless otherwise indicated by the context, and do not limit the order or importance of said objects.

[0040] Expressions used in the present disclosure, such as “A, B, and C,” “A, B, or C,” “A, B, and / or C,” or “at least one of A, B, and C,” “at least one of A, B, or C,” “at least one of A, B, and / or C,” “at least one selected from A, B, and C,” “at least one selected from A, B, or C,” or “at least one selected from A, B, and / or C,” may mean each of the listed items or all possible combinations of the listed items. For example, “at least one selected from A and B” may refer to (1) A, (2) at least one of A, (3) B, (4) at least one of B, (5) at least one of A and at least one of B, (6) at least one of A and B, (7) at least one of B and A, and (8) all of A and B.

[0041] The term “part” as used in this disclosure may be a collective concept encompassing software, or hardware components such as FPGAs (field-programmable gate arrays), ASICs (application-specific integrated circuits), and optical elements. However, “part” is not limited to hardware and software. “Part” may be configured to be stored in an addressable storage medium or configured to execute one or more processors. In one embodiment, “part” may include components such as software components, object-oriented software components, class components, and task components, as well as processors, functions, attributes, procedures, subroutines, segments of program code, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, and variables.

[0042] The expression “based on” as used in this disclosure is used to describe one or more factors affecting an act or action of a decision or judgment described in the phrase or sentence containing such expression, and this expression does not exclude additional factors affecting said act or action of a decision or judgment.

[0043] As used in the present disclosure, the expression that a certain component (e.g., a first component) is "connected" or "connected" to another component (e.g., a second component) may mean that the said certain component is not only directly connected or connected to the said other component, but is also connected or connected through a new other component (e.g., a third component).

[0044] As used in this disclosure, the expression "configured to" may have meanings such as "set to," "capable of," "modified to," "made to," or "capable of." Such expression is not limited to the meaning of "specifically designed in hardware," and, for example, a processor configured to perform a specific operation may mean a generic-purpose processor capable of performing that specific operation by executing software.

[0045] To describe various embodiments of the present disclosure, an orthogonal coordinate system having mutually orthogonal X-axis, Y-axis, and Z-axis may be defined. Expressions such as "X-axis direction," "Y-axis direction," and "Z-axis direction" used in the present disclosure may refer to the two directions in which each axis of the orthogonal coordinate system extends, unless specifically defined otherwise in the description. Additionally, a + sign preceding each axis direction may indicate a positive direction, which is one of the two directions extending in that axis direction, and a - sign preceding each axis direction may indicate a negative direction, which is the other of the two directions extending in that axis direction.

[0046] Directional indicators used in this disclosure, such as "upward" and "upward," are based on the positive Z-axis direction in the attached drawings unless specifically defined otherwise in the description, and directional indicators, such as "downward" and "downward," mean the opposite direction.

[0047] In the present disclosure, a substrate is a plate or container for mounting devices such as semiconductor chips or dies, and can serve as a pathway for electrical signals between devices. The substrate may be used for the fabrication of integrated circuits, etc., and may be made of a material such as silicon. For example, the substrate may be a printed circuit board (PCB), and may be referred to as a wafer, etc., depending on the embodiment.

[0048] Here, 'device' may refer to a component or chipset used as a constituent in electronic devices in general, such as electrical circuits and semiconductor devices. For example, a device may include coils, capacitors, resistors, transistors, diodes, LEDs, etc.

[0049] Various embodiments of the present disclosure will be described below with reference to the accompanying drawings. In the accompanying drawings and the description thereof, identical or substantially equivalent components may be given the same reference numerals. Furthermore, in the description of the various embodiments below, the description of identical or corresponding components may be omitted, but this does not mean that such components are not included in the embodiments.

[0050] FIG. 1 is a schematic diagram showing an apparatus (100) according to one embodiment of the present disclosure. A technique for controlling the imaging height of an image sensor for imaging a printed circuit board (PCB) according to one embodiment can be implemented through an apparatus (e.g., apparatus (100)) according to various embodiments.

[0051] In one embodiment, the device (100) may include one or more light sources (110), an image sensor (120), and / or a conveyor belt (140). One or more light sources (110) and an image sensor (120) may be implemented as a single integrated imaging device (130). The device (100) may further include one or more processors capable of controlling one or more light sources (110), an image sensor (120), and a conveyor belt (140). In this case, one or more processors may be electrically connected to one or more light sources (110), an image sensor (120), and a conveyor belt (140). In this specification, one or more processors may be referred to as processors. That is, the expression processor may mean a set of one or more processors unless the context clearly indicates otherwise.

[0052] In one embodiment, the conveyor belt (140) may represent a conveyor system. A printed circuit board may be placed within the conveyor belt (140). The conveyor belt (140) may include a conveyor rail (150) as a component. Additionally, the conveyor belt (140) may further include one or more sensing sensors (190) as a component. However, the one or more sensing sensors (190) are not essential components of the conveyor belt (140).

[0053] However, for clarity of explanation, the conveyor belt (140), the conveyor rail (150), and one or more sensing sensors (190) are described as distinct devices. In this case, "conveyor belt (140)" is used to refer to the belt itself. The conveyor rail (150) can support the conveyor belt (140). The conveyor rail (150) can be designed as a fixed structure or can be separated into multiple parts and arranged to support the conveyor belt (140). Additionally, a single printed circuit board may be placed on the conveyor belt (140), but is not limited thereto, and multiple printed circuit boards may be placed simultaneously on the conveyor belt (140). The processor (160) can drive the conveyor belt (140) to move the printed circuit board located on the conveyor belt (140). One or more sensing sensors (190) can detect the printed circuit board located on the conveyor belt (140) and generate a sensing signal. The detection signal generated from one or more detection sensors (190) can be utilized as a feedback mechanism to control the movement speed and direction of movement of the conveyor belt (140). Below, the case in which a target printed circuit board is placed on the conveyor belt (140) is mainly described.

[0054] In one embodiment, one or more light sources (110) may irradiate pattern light toward at least a portion of a target printed circuit board to perform an inspection using pattern light. An image sensor (120) may capture reflected light generated by the pattern light irradiated by one or more light sources (110) being reflected from at least a portion of the target printed circuit board, and may generate an image of the target printed circuit board using the captured reflected light. The image sensor (120) may transmit the generated image to a processor.

[0055] In one embodiment, the processor may receive an image of a target printed circuit board generated by the image sensor (120) from the image sensor (120). Based on the received image, the processor may determine a height offset value representing the vertical distance between the upper surface of the target printed circuit board and the image sensor for capturing the target printed circuit board. The processor may control the capturing height of the image sensor (120) according to the determined height offset value. When the capturing height of the image sensor (120) is adjusted according to the height offset value for the target printed circuit board, one or more lenses included in the image sensor (120) can be accurately focused on the upper surface of the target printed circuit board.

[0056] In one embodiment, an imaging device (130) comprising one or more light sources (110) and an image sensor (120) may have its position controlled by a processor. For example, the processor may move the imaging device (130) horizontally on a first plane parallel to the plane on which the target printed circuit board is placed. Additionally, the processor may move the imaging device (130) vertically on a second plane perpendicular to the first plane. The height of the image sensor (120) may be controlled through the vertical control of the imaging device (130). However, the method of controlling the imaging height of the image sensor (120) is not limited thereto, and an embodiment is also possible in which the imaging height is controlled by separating only the image sensor (120) from other components of the imaging device (130) (e.g., one or more light sources (110)) without moving the imaging device (130).

[0057] Additionally, the device (100) can control the imaging height of the image sensor (120) according to the height offset value of the target printed circuit board, and then move the target printed circuit board to a preset target position using a conveyor belt (140). As the target printed circuit board reaches the target position, the device (100) can perform imaging of the target printed circuit board using an imaging device (130). At this time, since the imaging height of the image sensor (120) is controlled by the processor according to the height offset value, one or more lenses included in the image sensor (120) are accurately focused on the upper surface of the target printed circuit board, and thereby the imaging device (130) can generate an image of the target printed circuit board more accurately and precisely. And, the device (100) can perform high-precision inspection through the precise image of the target printed circuit board.

[0058] FIG. 2 is a block diagram of a device (100) according to one embodiment of the present disclosure. In one embodiment, the device (100) may include one or more light sources (110), image sensors (120), conveyor belts (140), processors (160), memory (170), and / or communication circuits (180). In one embodiment, at least one of these components of the device (100) may be omitted, or other components may be added to the device (100). In one embodiment, additionally or alternatively, some components may be implemented as a single or multiple entities. The term "memory" may mean a set of one or more memories unless the context clearly indicates otherwise. In one embodiment, at least some of the components inside and outside the device (100) may be connected to each other via a bus, GPIO (general purpose input / output), SPI (serial peripheral interface) or MIPI (mobile industry processor interface), etc., to exchange data and / or signals.

[0059] In one embodiment, a target printed circuit board (101) may be placed on a conveyor belt (140). The conveyor belt (140) may move in a first axis direction (e.g., x-axis) by a control signal received from a processor (160). For example, the conveyor belt (140) may move in a +x-axis direction or a -x-axis direction. Additionally, in some cases, the conveyor belt (140) may move in a second axis direction. For example, the second axis may represent an axis (e.g., y-axis) orthogonal to the first axis within a plane parallel to the upper surface of the conveyor rail (150) (or conveyor belt (140)) (i.e., the plane on which the target printed circuit board is placed). Additionally, the target printed circuit board (101) may move along with the movement of the conveyor belt (140). In this way, the conveyor belt (140) can move the target printed circuit board (101) to an inspection position.

[0060] In one embodiment, each of the one or more light sources (110) may irradiate one or more patterned lights. For example, as the target printed circuit board (101) reaches an inspection position, the one or more light sources (110) may irradiate one or more first patterned lights onto the inspection area and inspection reference plane of the target printed circuit board (101). Here, the inspection reference plane may be one or more areas included in a conveyor belt in the sense of a conveyor system. At this time, the one or more light sources (110) may generate patterned lights in various ways. The pattern of the patterned light may be formed by a digital method or by an analog method. Digital methods may include a liquid crystal transmission method using an LCD (Liquid Crystal Display), a liquid crystal reflection method using LCoS (Liquid Crystal on Silicon), and a mirror reflection method using a DMD (Digital Micromirror Device) or DLP (Digital Light Processing). Analog methods may include a method of forming a pattern using patterns such as periodic patterns, gradient patterns, and grid patterns.

[0061] In one embodiment, the image sensor (120) can capture one or more reflected light. For example, the image sensor (120) can capture one or more first reflected light generated by one or more first pattern light being reflected from an inspection area and an inspection reference plane of a target printed circuit board (101). Based on the one or more captured first reflected light, the image sensor (120) can generate one or more first images including an inspection area and an inspection reference plane of a target printed circuit board (101). The image sensor (120) can transmit the generated one or more first images to a processor (160). The image sensor (120) may be implemented as a Charge Coupled Device (CCD) or a Complimentary Metal Oxide Semiconductor (CMOS) sensor, etc.

[0062] In one embodiment, the processor (160) can control at least one component (e.g., one or more light sources (110), image sensors (120), conveyor belts (140), communication circuits (180)) of a device (100) connected to the processor (160) by driving software (e.g., commands, programs, etc.). Additionally, the processor (160) can perform various operations such as computation, processing, data generation, and processing related to the present disclosure. Additionally, the processor (160) can perform various operations such as computation, processing, data generation, and processing related to the present disclosure. Additionally, the processor (160) can load data, etc. from memory (170) or store it in memory (170).

[0063] In one embodiment, the processor (160) may receive one or more first images from the image sensor (120). Based on the one or more received first images, the processor (160) may determine a first distance representing a height difference between an inspection area of ​​the target printed circuit board (101) and an inspection reference plane. Based on the determined first distance, the processor (160) may determine a height offset value representing a vertical distance between the upper surface of the target printed circuit board (101) and the image sensor (120) for imaging the target printed circuit board (101). The processor (160) may control the imaging height of the image sensor (120) according to the determined height offset value.

[0064] The memory (170) can store various data. The data stored in the memory (170) may include software (e.g., instructions, programs, etc.) as data acquired, processed, or used by at least one component of the device (100). The memory (170) may include volatile and / or non-volatile memory. In the present disclosure, instructions or programs are software stored in the memory (170) and may include an operating system for controlling the resources of the device (100), an application, and / or middleware that provides various functions to the application so that the application can utilize the resources of the device (100). In one embodiment, the memory (170) may store instructions that cause the processor (160) to perform calculations when executed by the processor (160).

[0065] In one embodiment, the communication circuit (180) can perform wireless or wired communication between the device (100) and a server or between the device (100) and another device. For example, the communication circuit (180) can perform wireless communication according to methods such as eMBB (enhanced Mobile Broadband), URLLC (Ultra Reliable Low-Latency Communications), MMTC (Massive Machine Type Communications), LTE (Long-Term Evolution), LTE-A (LTE Advance), NR (New Radio), UMTS (Universal Mobile Telecommunications System), GSM (Global System for Mobile communications), CDMA (Code Division Multiple Access), WCDMA (Wideband CDMA), WiBro (Wireless Broadband), WiFi (Wireless Fidelity), Bluetooth, NFC (Near Field Communication), GPS (Global Positioning System), or GNSS (Global Navigation Satellite System). For example, the communication circuit (180) can perform wired communication according to methods such as USB (Universal Serial Bus), HDMI (High Definition Multimedia Interface), RS-232 (Recommended Standard-232), or POTS (Plain Old Telephone Service). In one embodiment, the processor (160) can control the communication circuit (180) to obtain information necessary to implement the technology according to the present disclosure from a server. The information obtained from the server can be stored in memory (170).In one embodiment, the information obtained from the server may include substrate information for the target printed circuit board (101), information about the location of the inspection reference surface, etc.

[0066] FIGS. 3a and 3b are drawings illustrating the process of a device according to one embodiment of the present disclosure moving a target printed circuit board to an inspection position.

[0067] In one embodiment, the processor (160) of the device (100) can move a target printed circuit board (101) placed on a conveyor belt (140) from an initial position (310) to an inspection position (320). Referring to FIG. 3a, the target printed circuit board (101) may first be placed at the initial position (310). The processor (160) can detect that the target printed circuit board (101) on the conveyor belt (140) is placed at the initial position (310) through a detection sensor (190). FIG. 3b illustrates each corner included in the target printed circuit board (101). For example, the target printed circuit board (101) may include a first corner (102) at the bottom right, a second corner (103) at the bottom left, a third corner (104) at the top right, and a fourth corner (105) at the top left.

[0068] Referring again to FIG. 3a, the fact that the target printed circuit board (101) is placed at the initial position (310) may indicate, for example, that the first corner (102) of the target printed circuit board (101) is aligned with the initial position (310). That is, it may indicate that the first axis coordinate of the first corner (102) of the target printed circuit board (101) is adjusted to be the same as the first axis coordinate of the initial position (310). Here, the first axis may represent an axis (e.g., x-axis) parallel to the main direction of movement of the conveyor belt (140). In this specification, the conveyor belt (140) is primarily described as moving from right to left (e.g., in the +x-axis direction) to move from the initial position (310) to the inspection position (320), but is not limited thereto, and the conveyor belt (140) may also move from left to right (e.g., in the -x-axis direction) to move from the initial position (310) to the inspection position (320). In other words, the initial position (310) may be located to the left of the inspection position (320).

[0069] In one embodiment, the processor (160) can drive the conveyor belt (140) to move the target printed circuit board (101) from an initial position (310) toward an inspection position (320). For example, the inspection position (320) may be set to a position close to an inspection reference plane (330). In another example, the inspection position (320) may be set to an inspection reference plane (330). The inspection reference plane (330) may be positioned parallel to the upper surface of the conveyor rail (150) supporting the conveyor belt (140). Additionally, in addition to the inspection reference plane (330) located on one side of the conveyor belt (140), an inspection reference plane (331) of the same height may be positioned on the side opposite to that side. For example, the inspection reference plane (331) may be positioned symmetrically with respect to the inspection reference plane (330) with respect to a plane symmetrically crossing the conveyor rails (150) on both sides.

[0070] FIG. 4 is a drawing for illustrating an inspection reference surface (330) according to one embodiment of the present disclosure. The inspection reference surface (330) may be designed to have a preset height difference from the upper surface of the conveyor rail (150). For example, the preset height difference may be 5 mm, but is not limited thereto.

[0071] FIG. 4 illustrates a state in which the conveyor belt (140) is removed (or detached) from the conveyor rail (e.g., the conveyor rail (150) of FIG. 1). The conveyor belt (140) may be removable and reattached to the conveyor rail (150). The inspection reference surface (330) may be located between the first conveyor rail (151), which is located below the initial position (310) where the target printed circuit board (101) is placed, and the second conveyor rail (152), which is connected to a clamp (410) for securing the printed circuit board.

[0072] In one embodiment, the clamp (410) may be used to restrict the positional movement of the target printed circuit board (101) as the target printed circuit board (101) moves to the inspection position (320). That is, the processor (160) may control the clamp (410) to fix the target printed circuit board (101) at the inspection position (320) as the target printed circuit board (101) reaches the inspection position (320). Additionally, the processor (160) may control the clamp (410) to fix the target printed circuit board (101) at the target position when the target printed circuit board (101) is placed at the target position for board inspection after the imaging height of the image sensor (120) is adjusted by the height offset value. The clamp (410) can move in a vertical direction to effectively restrict the positional movement of the printed circuit board, thereby enabling stable imaging through the imaging device (130).

[0073] In one embodiment, the first conveyor rail (151) and the second conveyor rail (152) are separated from each other, so that the upper surface of the first conveyor rail (151) and the upper surface of the second conveyor rail (152) have the same height. At this time, an inspection reference surface (330) may be located between the first conveyor rail (151) and the second conveyor rail (152). Additionally, when a conveyor belt (140) is mounted on the conveyor rail (150), the conveyor belt (140) may be positioned over the upper surface of the first conveyor rail (151) and the upper surface of the second conveyor rail (152). At this time, the conveyor belt (140) may be located on the lower side of the inspection reference surface (330). However, not limited thereto, the first conveyor rail (151) and the second conveyor rail (152) may be connected to each other. In this case, an inspection reference surface (330) may be positioned on the upper portion of at least part of the conveyor rail (150). The inspection reference surface (330) may be designed to have a preset height difference (e.g., 5 mm) with respect to the upper surface of the first conveyor rail (151) and the upper surface of the second conveyor rail (152), respectively. The processor (160) may determine a first distance representing the height difference between the target printed circuit board (101) and the inspection reference surface (330), and may determine a height offset value for imaging the target printed circuit board (101) based on the determined first distance.

[0074] Referring again to FIG. 3a, the processor (160) can move a target printed circuit board (101) placed on a conveyor belt (140) to an inspection position (320). For example, moving the target printed circuit board (101) to an inspection position (320) by the processor (160) may include moving the conveyor belt (140) so that the corners of the target printed circuit board (101) (e.g., a first corner (102) or a second corner (103)) are aligned with the inspection position (320). Additionally, the processor (160) moving the target printed circuit board (101) to the inspection position (320) may include controlling the conveyor belt (140) such that the first axis coordinate and the second axis coordinate of the corner (e.g., the first corner (102) or the second corner (103)) of the target printed circuit board (101) match the first axis coordinate and the second axis coordinate of the inspection position (320), respectively. The processor (160) may move the conveyor belt (140) in the first axis direction so that the first axis coordinate of the corner (e.g., the first corner (102) or the second corner (103)) and the first axis coordinate of the inspection position (320) match, and may move the conveyor belt (140) in the second axis direction so that the second axis coordinate of the corner (e.g., the first corner (102) or the second corner (103)) and the second axis coordinate of the inspection position (320) match. However, for convenience of explanation, the present specification mainly describes controlling the conveyor belt (140) so that the first axis coordinate of the corner of the target printed circuit board (101) (e.g., the first corner (102) or the second corner (103)) matches the first axis coordinate of the inspection position (320), and the description regarding the matching of the second axis coordinate is omitted.

[0075] For example, the processor (160) can control the conveyor belt (140) so that the first axis coordinate of the first corner (102) of the target printed circuit board (101) matches the first axis coordinate of the inspection position (320). The processor (160) can calculate the travel distance of the conveyor belt (140) to move the target printed circuit board (101) to the inspection position (320). At this time, information regarding the target distance (d) from the initial position (310) to the inspection position (320) may be stored in advance in the memory (170). Here, the target distance (d) may represent the distance along the first axis from the initial position (310) to the inspection position (320). The processor (160) can extract the target distance (d) from the memory (170) and move the conveyor belt (140) by the target distance (d) in the first axis direction (e.g., +x axis direction).

[0076] In another example, the processor (160) can control the conveyor belt (140) such that the first axis coordinate of the second corner (103) of the target printed circuit board (101) matches the first axis coordinate of the inspection position (320). At this time, the processor (160) can receive board information of the target printed circuit board (101) from the memory (170) and can extract the first axis length (h) of the target printed circuit board (101) from the received board information. The processor (160) can move the conveyor belt (140) in the first axis direction (e.g., +x axis direction) by a distance (dh) obtained by subtracting the first axis length (h) of the target printed circuit board (101) from the target distance (d) from the initial position (310) to the inspection position (320).

[0077] In one embodiment, the processor (160) can move the target printed circuit board (101) to the inspection position (320) and then move the imaging device (130) toward the inspection position (320). Specifically, the processor (160) can move the imaging device (130) to a position where the imaging device (130) can capture both the inspection area (340) and the inspection reference plane (330) of the target printed circuit board (101). For example, the processor (160) can adjust the position of the imaging device (130) within a plane parallel to the conveyor rail (150) while maintaining the imaging height of the imaging device (130). In other words, the position of the imaging device (130) can be adjusted through lateral movement while maintaining the initial imaging height of the image sensor of the imaging device (130). The imaging device (130) can move within a plane parallel to the upper surface of the conveyor rail (150).

[0078] In one embodiment, the inspection area (340) of the target printed circuit board (101) may be designed so that the imaging device (130) can easily identify it. The target printed circuit board (101) may include one or more inspection areas (e.g., inspection area (340)). For example, the inspection area (340) of the target printed circuit board (101) may include a fiducial mark, which plays an important role in determining the placement position or rotation of the printed circuit board during the inspection process of the printed circuit board. For example, the fiducial mark is an element that provides a reference point for position recognition on the printed circuit board and may be configured in a geometric shape so that the processor (160) can easily detect it. Commonly used shapes include a circle, a cross shape, a triangle, etc., and such shapes may be selected considering both ease of recognition and ease of the manufacturing process. The processor (160) can verify the accurate placement of the target printed circuit board (101) through the inspection area (340) captured by the imaging device (130).

[0079] In one embodiment, since the target printed circuit board (101) is placed on the conveyor belt (140), as the conveyor belt (140) moves in the first axial direction (e.g., +x-axis direction), it moves in the same direction as the movement of the conveyor belt (140). However, due to friction between the conveyor belt (140) and the target printed circuit board (101), the target printed circuit board (101) may move a different distance, i.e., longer or shorter than the distance the conveyor belt (140) actually traveled (i.e., the target distance (d) or the distance (dh) obtained by subtracting the first axial length (h) of the target printed circuit board (101) from the target distance (d). As a result, the target printed circuit board (101) may not be positioned correctly at the inspection position (320). Therefore, the processor (160) can fine-tune the position of the imaging device (130) to correct this position error. In one embodiment, the processor (160) may fine-tune the position of the imaging device (130) so that the imaging device (130) irradiates one or more first pattern lights onto an inspection area (340) and an inspection reference plane (330) included in the target printed circuit board (101). The adjustment of the position of the imaging device (130) by the processor (160) is described in more detail in FIG. 7.

[0080] FIG. 5 is a diagram illustrating the process of determining the initial imaging height of an image sensor according to one embodiment of the present disclosure. In one embodiment, the processor (160) of the device (100) may determine the initial imaging height of the image sensor (120). The initial imaging height of the image sensor (120) may be determined in advance before the target printed circuit board (101) is loaded onto the conveyor belt (140).

[0081] First, a calibration jig (510) can be placed on the conveyor rail (150) with the conveyor belt (140) removed from the conveyor rail (150). The processor (160) can set the initial imaging height of the image sensor (120) to a first height at which the image sensor (120) is focused on the upper surface (511) of the calibration jig (510) placed on the conveyor rail (131) with the conveyor belt (140) removed from the conveyor rail (150). That is, the processor (160) can set the initial imaging height of the image sensor (120) such that the vertical distance between the image sensor (120) and the upper surface (511) of the calibration jig (510) becomes the focal length of one or more lenses included in the image sensor (120). For example, the thickness (521) of the calibration jig (510) may be 5mm, but is not limited to this.

[0082] In one embodiment, the inspection reference surface (330) and the upper surface (511) of the calibration jig (510) may be located at different heights from each other. For example, referring to FIG. 5, the thickness (521) of the calibration jig (510) may be greater than the height difference (522) between the inspection reference surface (330) and the upper surface of the conveyor rail (150). In another embodiment, the thickness (521) of the calibration jig (510) may be designed to be equal to the height difference (522) between the inspection reference surface (330) and the upper surface of the conveyor rail (150). In this case, the inspection reference surface (330) and the upper surface (511) of the calibration jig (510) may be located at the same height from each other.

[0083] In one embodiment, the processor (160) may set the inspection position (320) such that the distance from the inspection reference plane (330) to the inspection position (320) is less than or equal to the first axis length of the field of view (FOV) that the image sensor (120) can capture at a first height. Here, the distance from the inspection reference plane (330) to the inspection position (320) may represent the first axis distance from the center point of the inspection reference plane (330) to the inspection position (320). By setting the distance between the inspection position (320) and the inspection reference plane (330) to be less than or equal to the first axis length of the field of view that the image sensor (120) can capture at a first height, the processor (160) may enable the image sensor (120) to capture the inspection reference plane (330) and the inspection position (320) at once (or simultaneously).

[0084] In another embodiment, the processor (160) can extract the distance between the corner of the target printed circuit board and the inspection area (340) that is aligned with the inspection position (320) from the substrate information of the target printed circuit board (101). Here, the distance between the corner and the inspection area (340) may represent a first axis distance between the corner and the inspection area (340). In this case, the processor (160) may set the inspection position (320) such that the distance from the inspection reference plane (330) to the inspection area (340) is less than or equal to the first axis length of the observation area that the image sensor (120) can capture at a first height.

[0085] Hereinafter, the process of determining a height offset value for imaging a target printed circuit board (101) by the device (100) is described. One or more light sources (110) may irradiate one or more second pattern lights onto at least a portion of the upper surface (511) of the calibration jig (510) and the inspection reference surface (330). At this time, the second pattern light may be a pattern light of the same type as the first pattern light, but is not limited thereto. An image sensor (120) may capture one or more second reflected lights generated by one or more second pattern lights reflecting from at least a portion of the upper surface (511) of the calibration jig (510) and the inspection reference surface (330). Then, the image sensor (120) may generate one or more second images including at least a portion of the upper surface (511) of the calibration jig (510) and the inspection reference surface (330), and transmit one or more generated second images to a processor (160). The processor (160) can determine a second distance (523) representing a height difference between the upper surface (511) of the calibration jig (510) and the inspection reference surface (330) based on one or more received second images.

[0086] There may be various ways in which the processor (160) calculates the height difference between surfaces (e.g., top surface (511), inspection reference surface (330)) through one or more second images. For example, the processor (160) may calculate the height difference between surfaces using phase change. Specifically, one or more light sources (110) may convert one or more second pattern lights into multiple phases and continuously irradiate one or more second pattern lights onto at least a portion of the top surface (511) of the calibration jig and the inspection reference surface (330). The processor (160) may analyze the amount of phase change at each pixel through one or more acquired second images and extract depth information at each point according to the analyzed amount of phase change. That is, the processor (160) can obtain depth information of the upper surface (511) of the calibration jig (510) and the inspection reference surface (330) by analyzing the amount of phase change, and can determine a second distance (523) representing the height difference between the upper surface (511) of the calibration jig (510) and the inspection reference surface (330) based on the obtained depth information. As another example, the processor (160) can calculate the height difference between surfaces through pattern analysis (or pattern change). Specifically, one or more light sources (110) can irradiate structured light onto at least a portion of the upper surface (511) of the calibration jig and the inspection reference surface (330). The processor (160) can reconstruct the surface shape by analyzing the distorted pattern in one or more acquired second images, and can determine a second distance (523) representing the height difference between the upper surface (511) of the calibration jig (510) and the inspection reference surface (330) according to the reconstructed surface shape.

[0087] In one embodiment, the processor (160) may store a determined second distance (523) and a first height, which is the initial imaging height of the image sensor (120), in the memory (170). Hereinafter, FIG. 6 describes the process of the processor (160) determining a height offset value for imaging a target printed circuit board (101) using the determined second distance (523).

[0088] FIG. 6 is a diagram illustrating the process of determining a height offset value for imaging a target printed circuit board by an apparatus (100) according to one embodiment of the present disclosure. In one embodiment, after a second distance (523) representing a height difference between the upper surface (511) of a calibration jig (510) and an inspection reference surface (330) is determined, a conveyor belt (140) may be mounted on a conveyor rail (150), and a target printed circuit board (101) may be placed on the conveyor belt (140). Then, the target printed circuit board (101) may be placed on the conveyor belt (140). For example, the thickness of the conveyor belt (140) may be 2.4 mm, but is not limited thereto.

[0089] Meanwhile, it is not necessary to remove the conveyor belt (140) as described in FIG. 5 whenever a printed circuit board (e.g., target printed circuit board (101)) is inspected. As described above, the processor (160) may store a second distance (523) and a first height, which is the initial imaging height of the image sensor (120), in memory (170). Accordingly, whenever the processor (160) inspects a printed circuit board, it can set the initial imaging height of the image sensor (120) according to the first height stored in memory (170), and can use the second distance (523) stored in memory (170) to determine the height offset value of the printed circuit board.

[0090] In one embodiment, a conveyor belt (140) can move a target printed circuit board (101) to an inspection position (320). One or more light sources (110) can irradiate one or more first patterned light onto an inspection area (340) and an inspection reference plane (330) of the target printed circuit board (101) as the target printed circuit board (101) reaches the inspection position (320). An image sensor (120) can capture one or more first reflected light generated by the one or more first patterned light being reflected from the inspection area (340) and the inspection reference plane (330) of the target printed circuit board (101). The image sensor (120) can generate one or more first images including the inspection area (340) and the inspection reference plane (330) of the target printed circuit board (101) and transmit the generated one or more first images to a processor (160). The processor (160) can determine a first distance (610) representing a height difference between an inspection area (340) and an inspection reference plane (330) of a target printed circuit board (101) based on one or more received first images. For example, the processor (160) can determine the first distance (610) using a phase change or pattern analysis technique. A method for determining a height difference between surfaces using pattern light is similarly described in FIG. 5, so a detailed description is omitted.

[0091] In one embodiment, the processor (160) can determine a height offset value for the target printed circuit board (101) based on a first distance (610) and a second distance (523). For example, when the conveyor belt (140) is removed from the conveyor rail (150), the upper surface (511) of the calibration jig (510) may be positioned higher than the inspection reference surface (330), and the inspection area (340) of the target printed circuit board (101) placed on the conveyor belt (140) may be positioned lower than the inspection reference surface (330). In this case, the processor (160) can determine a height offset value for the target printed circuit board (101) by summing the first distance (610) and the second distance (523). In another example, when the conveyor belt (140) is removed from the conveyor rail (150), the upper surface of the calibration jig (510) may be positioned lower than the inspection reference surface (330), and the inspection area (340) of the target printed circuit board (101) placed on the conveyor belt (140) may also be positioned lower than the inspection reference surface (330). Additionally, the upper surface of the calibration jig (510) may have a position higher than the target printed circuit board (101). That is, the second distance (523) may be smaller than the first distance (610). In this case, the processor (160) can determine a height offset value for the target printed circuit board (101) by subtracting the second distance (523) from the first distance (610). The imaging height of the image sensor (120) may be set to a first height focused on the upper surface (511) of the calibration jig (510) when the target printed circuit board (101) and the conveyor belt (140) are removed from the conveyor rail (150). Subsequently, the processor (160) may set a height adjustment value of the image sensor (120) so that the image sensor (120) can focus on the target printed circuit board (101), and this value may represent a height offset value.For example, if the upper surface (511) of the calibration jig (510) is located at the same height as the inspection reference surface (330), the second distance (523) may be '0'. In this case, the processor (160) may determine the height offset value for the target printed circuit board (101) as the first distance (610).

[0092] FIG. 7 is a diagram illustrating the process of adjusting the position of an imaging device (130) by a device (100) according to one embodiment of the present disclosure. In one embodiment, the processor (160) of the device (100) may move the image sensor (120) within a plane (710) parallel to the upper surface of the conveyor rail (150) so that, as the target printed circuit board (101) reaches the inspection position (320), the image sensor (120) has an observation area (720) including an inspection area (340) and an inspection reference plane (330). At this time, the imaging height of the image sensor (120) of the imaging device (130) may be set to a first height focused on the upper surface (511) of the calibration jig (510).

[0093] In one embodiment, coordinate information corresponding to an inspection reference plane (330) may be stored in advance in the memory (170) of the device (100). For example, the coordinate information corresponding to the inspection reference plane (330) may include a first axis coordinate and a second axis coordinate. As described above, the first axis may represent an axis parallel to the direction of movement of the conveyor belt (140) (e.g., x-axis), and the second axis may represent an axis orthogonal to the first axis (e.g., y-axis) within a plane (710) parallel to the upper surface of the conveyor rail (150). Additionally, the coordinate information corresponding to the inspection reference plane (330) may represent, for example, the coordinate information of the center point of the inspection reference plane (330). However, it is not limited thereto, and the coordinate information corresponding to the inspection reference plane (330) may be, for example, the coordinate information of a corner (e.g., bottom right corner) included in the inspection reference plane (330).

[0094] In one embodiment, substrate information of a target printed circuit board (101) may be stored in advance in the memory (170) of the device (100). A processor (160) may extract location information of an inspection area (340) included in the target printed circuit board (101) from the substrate information of the target printed circuit board (101). Here, the location information of the inspection area (340) included in the target printed circuit board (101) may be, for example, location information of the center point of the inspection area (340) calculated based on the first corner (102) of the target printed circuit board (101), but is not limited thereto. At this time, the processor (160) may align the first corner (102) of the target printed circuit board (101) with the inspection location (320). In this case, the processor (160) may calculate the coordinate information of the inspection area (340) using the coordinate information of the inspection location (320). That is, the processor (160) can calculate the coordinate information of the inspection area (340) by reflecting the location information of the inspection area (340) in the coordinate information of the inspection location (320). For example, the processor (160) can calculate the coordinate information of the inspection area (340) by determining that the coordinate information of the first corner (102) of the target printed circuit board (101) matches the coordinate information of the inspection location (320). As another example, even if the first corner (102) of the target printed circuit board (101) is aligned with the inspection location (320), the coordinate information of the first corner (102) and the inspection location (320) may not match due to friction between the target printed circuit board (101) and the conveyor belt (140). In this case, the processor (160) may cause the imaging device (130) to capture the inspection position (320) and the inspection area (340) of the target printed circuit board (101) as the target printed circuit board (101) reaches the inspection position (320), and may calculate coordinate information of the inspection area (340) based on the inspection position (320) from the captured image.

[0095] In one embodiment, the processor (160) can move the image sensor (120) within a plane (710) parallel to the upper surface of the conveyor rail (150) so that the image sensor (120) has an observation area (720) that includes coordinate information of the inspection reference plane (330) (e.g., first axis coordinates and second axis coordinates) and coordinate information of the inspection area (340) (e.g., first axis coordinates and second axis coordinates). For example, the processor (160) can move the image sensor (120) along the first axis and the second axis within the plane (710) parallel to the upper surface of the conveyor rail (150) so that the center of the observation area (720) of the image sensor (120) is located at the midpoint of the coordinate information of the inspection reference plane (330) and the coordinate information of the inspection area (340).

[0096] FIG. 8 is a diagram illustrating a process in which a device according to one embodiment of the present disclosure calculates a height offset value using a plurality of inspection regions included in a target printed circuit board. In one embodiment, the target printed circuit board (101) may include one or more inspection regions (e.g., inspection region (340)). Hereinafter, an embodiment in which the target printed circuit board (101) includes a plurality of inspection regions (340, 350, 360, 370) is described.

[0097] In one embodiment, the processor (160) of the device (100) can individually calculate the height difference from the inspection reference plane (330) for each of the plurality of inspection areas (340, 350, 360, 370) included in the target printed circuit board (101). For example, the processor (160) can calculate the height difference (e.g., m1) between the inspection area (340) and the inspection reference plane (330). Similarly, the processor (160) can calculate the height difference (e.g., m2) between the inspection area (350) and the inspection reference plane (330), the height difference (e.g., m3) between the inspection area (360) and the inspection reference plane (330), and the height difference (e.g., m4) between the inspection area (370) and the inspection reference plane (330), respectively. The processor (160) calculates the average value of the calculated height differences (e.g., The first distance can be calculated using ). For example, the processor (160) can calculate the average value of the calculated height difference (e.g., ) can be determined as the first distance. Subsequently, the processor (160) can determine a height offset value for the target printed circuit board (101) using the determined first distance and a second distance representing the height difference between the upper surface (511) of the calibration jig (510) and the inspection reference surface (330).

[0098] In one embodiment, at least some of the plurality of inspection areas may be located in a first corner area of ​​the target printed circuit board (101). Here, the first corner area may represent, for example, an area closer to the first corner (102) compared to other corners of the target printed circuit board (101). Referring to FIG. 8, inspection area (340) and inspection area (350) may be located in the first corner area of ​​the target printed circuit board (101). Additionally, the remaining inspection area, excluding at least some of the plurality of inspection areas, may be located in a second corner area of ​​the target printed circuit board (101) different from the first corner area. The second corner area may represent, for example, an area closer to the second corner (103) compared to other corners of the target printed circuit board (101). Referring to FIG. 8, inspection area (360) and inspection area (370) may be located in the second corner area of ​​the target printed circuit board (101). For example, the processor (160) may move the conveyor belt (140) so that the second corner (103) is aligned with the inspection position (320) in order to calculate the height difference between the inspection area (360) (or inspection area (370)) and the inspection reference surface (330), and then have the imaging device (130) capture the inspection area (360) (or inspection area (370)) and the inspection reference surface (330). For reference, an inspection reference surface (331) of the same height may be placed on the side opposite to the one where the inspection reference surface (330) is located. Thus, even if the inspection area is located in the third corner area or the fourth corner area of ​​the target printed circuit board (101), the height difference between the inspection reference surface (331) and the inspection area (360) (or inspection area (370)) can be calculated through the inspection reference surface (331) located on the side opposite to the inspection reference surface (330).At this time, the third corner area may represent, for example, an area closer to the third corner (104) compared to other corners of the target printed circuit board (101), and the fourth corner area may represent, for example, an area closer to the fourth corner (105) compared to other corners of the target printed circuit board (101).

[0099] FIG. 9 is a diagram illustrating the process of a device according to one embodiment of the present disclosure storing a height offset value for a target printed circuit board in work data.

[0100] In one embodiment, the processor (160) of the device (100) may store a height offset value determined for a target printed circuit board (101) in work data of a substrate type corresponding to the target printed circuit board (101) (e.g., first work data (911), second work data (912), third work data (913)). For example, each of the first work data (911), second work data (912), and third work data (913) may represent work data corresponding to a first substrate type, a second substrate type, and a third substrate type. The processor (160) may identify a substrate type corresponding to the target printed circuit board (101) (e.g., first substrate type) and may store (or update) a height offset value determined for the target printed circuit board (101) in work data (e.g., first work data (911)) corresponding to the identified substrate type (e.g., first substrate type).

[0101] In one embodiment, after the substrate inspection of the target printed circuit board (101) is completed, a printed circuit board different from the target printed circuit board (101) and having the same substrate type as the target printed circuit board (101) may be placed on the conveyor belt (140). For example, the processor (160) may receive information on the substrate type of the printed circuit board placed on the conveyor belt (140) from the communication circuit (180). If the printed circuit board placed on the conveyor belt (140) has the same substrate type as the target printed circuit board (101), the processor (160) may extract a height offset value from the work data (e.g., first work data (911)) corresponding to the substrate type of the target printed circuit board (101) (e.g., first substrate type). Next, the processor (160) may control the imaging height of the image sensor (120) according to the extracted height offset value, that is, the height offset value determined for the target printed circuit board (101). In other words, the processor (160) can adjust the imaging height of the image sensor (120) without needing to recalculate a separate height offset value when the printed circuit board placed on the conveyor belt (140) has the same board type as the target printed circuit board (101), thereby improving the efficiency of the inspection process.

[0102] Various embodiments of the present disclosure may be implemented as software recorded on a machine-readable recording medium. The software may be software for implementing the various embodiments of the present disclosure described above. The software may be inferred from the various embodiments of the present disclosure by programmers skilled in the art to which the present disclosure pertains. For example, the software may be a machine-readable instruction (e.g., code or code segment) or a program. The machine may be a device capable of operating according to instructions called from the recording medium, for example, a computer. In one embodiment, the machine may be a device (100) according to the embodiments of the present disclosure. In one embodiment, the processor of the machine may execute the called instruction to cause the components of the machine to perform a function corresponding to the instruction. In one embodiment, the processor may be one or more processors according to the embodiments of the present disclosure. The recording medium may mean any type of recording medium in which data is stored that can be read by the machine. The recording medium may include, for example, ROM, RAM, CD-ROM, magnetic tape, floppy disk, optical data storage device, etc. In one embodiment, the recording medium may be one or more memories. In one embodiment, the recording medium may be implemented in a distributed form in a networked computer system, etc. Software may be stored and executed in a distributed manner in a computer system, etc. The recording medium may be a non-transitory recording medium. A non-transitory recording medium refers to a tangible medium that exists regardless of whether data is stored semi-permanently or temporarily, and does not include a signal that propagates transitorily.

[0103] Although the technical concept of the present disclosure has been described by various embodiments above, the technical concept of the present disclosure includes various substitutions, modifications, and alterations that can be made within the scope of understanding of those skilled in the art to which the present disclosure pertains. Furthermore, it should be understood that such substitutions, modifications, and alterations may be included within the scope of the appended claims.

Claims

1. A conveyor belt on which a target printed circuit board (PCB) is placed and which moves the target printed circuit board to an inspection position; A light source that irradiates one or more first pattern lights onto an inspection area and an inspection reference plane of the target printed circuit board as the target printed circuit board reaches the inspection position; An image sensor that captures one or more first reflected lights generated by the reflection of one or more first pattern lights from the inspection area and the inspection reference plane to generate one or more first images; One or more of the above processors; and It includes one or more memories in which instructions to be executed by the above one or more processors are stored, and When executing the above instructions, the one or more processors, Based on the above one or more first images, a first distance representing the height difference between the inspection area and the inspection reference plane is determined, and Based on the first distance above, a height offset value representing the vertical distance between the upper surface of the target printed circuit board and the image sensor for capturing the target printed circuit board is determined, and A device for controlling the imaging height of the image sensor according to the height offset value.

2. In Paragraph 1, The above inspection reference surface is, A device having a preset height difference from the upper surface of a conveyor rail supporting the conveyor belt.

3. In Paragraph 1, The above inspection reference surface is, A device located between a first conveyor rail located below the initial position where the above-mentioned target printed circuit board is placed, and a second conveyor rail connected to a clamp for fixing the printed circuit board.

4. In Paragraph 3, The above one or more processors, The conveyor belt is moved in the first axis direction by a distance from the initial position to the inspection position, and The above first axis is a device representing an axis parallel to the direction of movement of the conveyor belt.

5. In Paragraph 1, The initial imaging height of the above image sensor is, A device that is set to a first height focused on the upper surface of a calibration jig placed on the conveyor rail when the conveyor belt is removed from the conveyor rail.

6. In Paragraph 5, The above one or more processors, A device for setting an inspection position such that, based on the inspection reference plane, the distance from the inspection reference plane to the inspection position is less than or equal to the first axis length of the field of view (FOV) in which the image sensor can capture images at the first height.

7. In Paragraph 6, The above light source is, One or more second pattern lights are irradiated onto at least a portion of the upper surface of the calibration jig and the inspection reference surface, and The above one or more processors, An apparatus for determining a second distance representing a height difference between the upper surface of a calibration jig and the inspection reference surface, based on one or more second images capturing one or more second reflected lights generated by reflecting one or more second pattern lights from at least a portion of the upper surface of the calibration jig and the inspection reference surface.

8. In Paragraph 7, The above one or more processors, A device for determining the height offset value based on the first distance and the second distance.

9. In Paragraph 1, The above one or more processors, A device for moving an image sensor in a plane parallel to the upper surface of a conveyor rail, such that as the target printed circuit board reaches the inspection position, the image sensor has an observation area including the inspection area and the inspection reference plane.

10. In Paragraph 1, The above-mentioned target printed circuit board includes a plurality of inspection areas, and The above one or more processors, A device that individually calculates the height difference from the inspection reference plane for each of the plurality of inspection areas and calculates the first distance using the average value of the calculated height differences.

11. In Paragraph 10, At least some of the plurality of inspection regions are located in the first corner region of the target printed circuit board, and A device in which the remaining inspection area, excluding at least some of the above-mentioned multiple inspection areas, is located in a second corner area of ​​the target printed circuit board different from the first corner area.

12. In Paragraph 1, The above one or more processors, The above-determined height offset value is stored in the work data of the substrate type corresponding to the target printed circuit board, and A device for controlling the imaging height of an image sensor according to a determined height offset value when a printed circuit board different from the target printed circuit board, having the same substrate type as the target printed circuit board, is placed on the conveyor belt.

13. In a method for inspecting a printed circuit board, A step of driving a conveyor belt on which a target printed circuit board is placed to move the target printed circuit board to an inspection position; A step of irradiating one or more first pattern lights onto an inspection area and an inspection reference plane of the target printed circuit board as the target printed circuit board reaches the inspection position; A step of acquiring one or more first images by capturing one or more first reflected light generated by the one or more first patterned lights being reflected from the inspection area and the inspection reference plane; A step of determining a first distance representing a height difference between the inspection area and the inspection reference plane based on one or more first images; A step of determining a height offset value representing the vertical distance between the upper surface of the target printed circuit board and the image sensor for imaging the target printed circuit board based on the first distance; and A method comprising the step of controlling the imaging height of the image sensor according to the height offset value.

14. A non-transient computer-readable recording medium having instructions that cause one or more processors to perform an operation when executed by one or more processors, The above instructions cause the above one or more processors, A conveyor belt on which the target printed circuit board is placed is driven to move the target printed circuit board to an inspection position, and As the target printed circuit board reaches the inspection position, one or more first pattern lights are irradiated onto the inspection area and inspection reference plane of the target printed circuit board, and One or more first images are obtained by capturing one or more first reflected light generated by the one or more first patterned lights being reflected from the inspection area and the inspection reference plane, and Based on the above one or more first images, a first distance representing the height difference between the inspection area and the inspection reference plane is determined, and Based on the first distance above, a height offset value representing the vertical distance between the upper surface of the target printed circuit board and the image sensor for capturing the target printed circuit board is determined, and A non-transient computer-readable recording medium that controls the imaging height of the image sensor according to the height offset value.

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