Patent Description:
In general, at least one Printed Circuit Board (PCB) is provided in an electronic device and various circuit elements such as circuit patterns, connection pads, and driving chips electrically connected with the connection pads are mounted on the PCB.

A substrate formed by mounting electronic elements on a PCB is used in various electronic products. The substrate is manufactured by applying lead to pad areas of a bare substrate and coupling terminals of the electronic elements to the lead-applied areas.

A substrate inspection system performs a solder paste inspection (SPI) that inspects whether lead is properly applied to the pad areas of the PCB before the electronic elements are mounted on the PCB, and an automated optical inspection (AOI) that detects various types of defects relating to whether the electronic elements are properly soldered to the PCB after the electronic elements are mounted on the PCB.

In the related art, a user has checked an inspection result of an inspection object, and when the inspection result was bad, the user has stopped the substrate inspection system, mounted a calibration target on a work stage, and performed a calibration of the substrate inspection system. Accordingly, it is impossible to know whether the inspection performance has deteriorated, until a user checks the inspection result, so that there is the problem that PCBs that have not been properly inspected are manufactured as products. <CIT> discloses a dark-field defect inspecting method of obtaining, by a first sensor of a detection system, a signal of scattered light occurring due to illumination light illuminating a surface of an inspection subject, from the surface of the inspection subject and detecting a foreign substance or a defect on the inspection subject based on the signal obtained by the first sensor. <CIT> discloses a pattern inspection device having a light irradiator configured to irradiate a light on an inspection area set in a pattern forming location on a semiconductor wafer and an adjustment area set different from the inspection area in association with the inspection area on the semiconductor wafer.

The above technical problem can be solved by the features of the annexed claims. The present disclosure provides a method of verifying whether an inspection unit, capable of inspecting a defect of an inspected body, in an inspection apparatus has a fault, according to claim <NUM> and an inspection system according to claim <NUM>.

In an embodiment, the at least two fiducial markers indicate at least two positions for verifying an accuracy of movement of the inspection unit.

In an embodiment, positioning the inspection unit over the verification reference body includes positioning the inspection unit over the verification reference body based on an inspection defect rate of the inspection unit.

In an embodiment, the method further includes correcting a fault of the inspection unit by calibrating the inspection unit based on the verification result.

In an embodiment, the verification reference body is disposed in a concave portion of the frame.

In an embodiment, the inspection apparatus further includes: a cover configured to be capable of opening and closing the verification reference body disposed in the concave portion; and a driving unit moving the cover with respect to the verification reference body to open and close the verification reference body.

In an embodiment, the driving unit includes a rotating unit configured to rotate the cover to open and close the verification reference body.

In an embodiment, the driving unit includes a sliding unit configured to slide the cover to open and close the verification reference body.

In an embodiment, the inspection apparatus further includes a reflector disposed on the frame to verify whether a light source, configured to generate light, in the inspection unit has a fault.

In an embodiment, the reflector has a convex curve shape.

In an embodiment, the reflector has a concave curve shape.

Hereinafter, exemplary embodiments of the present disclosure will be described with reference to the accompanying drawings. However, in the following description, a detailed description of widely known functions or elements will be omitted, in case there is concern of unnecessarily making the gist of the present disclosure unclear.

<FIG> is a perspective view schematically showing an inspection system according to an embodiment of the present disclosure. Referring to <FIG>, an inspection system <NUM> includes an inspection unit <NUM>. The inspection unit <NUM> obtains image data of an inspected body by radiating light towards the inspected body and receiving light reflected from the inspected body, and inspects the inspected body based on the image data. In an embodiment, the inspected body includes a printed circuit board and the light includes pattern light and color light, but they are not limited thereto.

<FIG> is a diagram schematically showing a configuration of the inspection unit <NUM> according to an embodiment of the present disclosure. Referring to <FIG>, the inspection unit <NUM> includes first lighting portions <NUM>-<NUM> and <NUM>-<NUM>. The first lighting portions <NUM>-<NUM> and <NUM>-<NUM> radiate pattern light towards an inspected body B to measure an inspection object IO formed on the inspected body B. The inspection object IO includes a solder (not shown) formed on a pad of the inspected body B, electronic elements (not shown) or the like, however it is not limited thereto and may include all materials having a shape such as glass, plastic, and metals.

In an embodiment, the first lighting portions <NUM>-<NUM> and <NUM>-<NUM> include a light source <NUM> configured to generate light, a grating element <NUM> configured to convert the light from the light source <NUM> into pattern light, a grating-moving apparatus <NUM> configured to pitch-move the grating element <NUM>, and a projection lens <NUM> configured to project the pattern light, which is converted by the grating element <NUM>, onto the inspection object IO. The grating element <NUM> may be moved by a predetermined distance (e.g., 2π/N (where N is a natural number of <NUM> or more) through the grating-moving apparatus <NUM>, such as a PZT (piezo) actuator, for phase transition of the pattern light. Alternatively, instead of using the grating element <NUM> and the grating-moving apparatus <NUM>, it is possible to radiate the pattern light, using an image of a liquid crystal display (not shown). However, the present disclosure is not limited thereto and any other means may be used as long as it can radiate pattern light.

In an embodiment, one first lighting portion <NUM>-<NUM> or <NUM>-<NUM> may be installed or a plurality of first lighting portions may be installed to be spaced apart by a predetermined angle along a circumferential direction or a virtual polygonal plane. In another embodiment, a plurality of first lighting portions <NUM>-<NUM> and <NUM> may be installed to be spaced apart by a predetermined interval along a direction that is perpendicular to the inspected body B. In yet another embodiment, one first lighting portion <NUM>-<NUM> or <NUM>-<NUM> may be installed along a direction that is perpendicular to the inspected body B.

The inspection unit <NUM> further includes a second lighting portion <NUM>. The second lighting portion <NUM> radiates color light toward the inspected body B to measure the inspection object IO formed on the inspected body B. For example, the color light includes white light, red light, green light and blue light, however the color light is not limited thereto. In an embodiment, the second lighting portion <NUM> includes a first lamp <NUM>, a second lamp <NUM>, and a third lamp <NUM>.

The first lamp <NUM> is installed under the first lighting portions <NUM>-<NUM> and <NUM>-<NUM>. The first lamp <NUM> generates the color light, and radiates the color light towards the inspected body B. In an embodiment, the first lamp <NUM> may have a shape of a circle or a virtual polygon, however the first lamp <NUM> is not limited thereto. The first lamp <NUM> includes a first ring member 221a having an opening TH<NUM> for passing light (e.g., pattern light or color light) and at least one first light emitting element 221b, which is installed under the first ring member 221a, as a light source for generating the color light.

In an embodiment, the first lamp <NUM> may generate at least one color light. As one example, the first lamp <NUM> may generate color light having a first color (e.g., red). As another example, the first lamp <NUM> may generate color lights of red, green, and blue. The second lamp <NUM> is installed under the first lamp <NUM>. The second lamp <NUM> generates color light and radiates the color light towards the inspected body B. In an embodiment, the second lamp <NUM> may have a shape of a circle or a virtual polygon, however the second lamp <NUM> is not limited thereto. The second lamp <NUM> includes a second ring member 222a having an opening TH<NUM> for passing light (e.g., pattern light or color light) and at least one second light emitting element 222b, which is installed under the second ring member 222a, as a light source for generating the color light. In an embodiment, the opening TH<NUM> of the second lamp <NUM> may be larger in diameter than the opening TH<NUM> of the first lamp <NUM> so that the pattern light from the first lighting portions <NUM>-<NUM> and <NUM>-<NUM> or the color light from the first lamp <NUM> can be radiated towards the inspected body B, or light (e.g., pattern light or color light) reflected from the inspected body B can be radiated.

In an embodiment, the second lamp <NUM> may generate at least one color light. As one example, the second lamp <NUM> may generate a color light having a color (e.g., green) that is different from that of the color light generated by the first lamp <NUM>. As another embodiment, the second lamp <NUM> may generate color lights of red, green, and blue.

The third lamp <NUM> is installed under the second lamp <NUM>. The third lamp <NUM> generates color light, and radiates the color light towards the inspected body B. In an embodiment, the third lamp <NUM> may have a shape of a circle or a virtual polygon, however the third lamp <NUM> is not limited thereto. The third lamp <NUM> includes a third ring member 223a having an opening TH<NUM> for passing light (e.g., pattern light or color light) and at least one third light emitting element 223b, which is installed under the third ring member 223a, as a light source for generating the color light. In an embodiment, the opening TH<NUM> of the third lamp <NUM> may be larger in diameter than the opening TH<NUM> of the second lamp <NUM> so that the pattern light from the first lighting portions <NUM>-<NUM> and <NUM>-<NUM> or the color light from the first lamp <NUM> or second lamp <NUM> can be radiated towards the inspected body B or the light (e.g., pattern light or color light) reflected from the inspected body B can be radiated.

In an embodiment, the third lamp <NUM> may generate at least one color light. As one example, the third lamp <NUM> may generate a color light having a color (e.g., green) that is different from that of the color light generated by the first lamp <NUM> and the second lamp <NUM>. As another embodiment, the third lamp <NUM> may generate color lights of red, green, and blue.

Although the second lighting portion <NUM> includes the first lamp <NUM>, the second lamp <NUM>, and the third lamp <NUM> in the embodiment described above, however the second lighting portion <NUM> is not limited thereto. For example, the second lighting portion <NUM> may include at least one lamp.

The inspection unit <NUM> further includes an imaging portion <NUM>. The imaging portion <NUM> obtains image data of the inspected body B by receiving light reflected by the inspected body B. That is, the imaging portion <NUM> obtains the image data of the inspected body B by photographing the inspected body B through the radiation of the pattern light from the first lighting portions <NUM>-<NUM> and <NUM>-<NUM>. Further, the imaging portion <NUM> obtains the image data of the inspected body B by photographing the inspected body B through the radiation of the color light from the second lighting portion <NUM>. As one example, the imaging portion <NUM> may be installed at an upper position perpendicular to the inspected body B. As another example, a plurality of imaging portions <NUM> may be installed at an upper position perpendicular to the inspected body B and may be installed along a circumferential direction to be spaced apart by a predetermined angle. The imaging portion <NUM> may be a charge coupled device (CCD) camera or a complementary metal oxide semiconductor (CMOS) camera, however the imaging portion <NUM> is not limited thereto.

The inspection unit <NUM> shown in <FIG> is an example of an inspection device that can obtain image data of the inspected body B, so it should be noted that the inspection unit <NUM> is not limited to the configuration shown in <FIG>.

Referring back to <FIG>, the inspection system <NUM> further includes a moving unit <NUM>. The moving unit <NUM> moves the inspected body B to the inspection unit <NUM>. The moving unit <NUM> may include a conveyer (not shown) or the like, but the moving unit <NUM> is not limited thereto.

The inspection system <NUM> further includes an inspection apparatus <NUM> for verifying whether the inspection unit <NUM> has a fault. In an embodiment, the inspection apparatus <NUM> may be attached to a side of the inspection system <NUM>. For example, the inspection apparatus <NUM> is attached to a side of the moving unit <NUM>, however the inspection apparatus <NUM> is not limited thereto.

<FIG> is a perspective view schematically showing a configuration of the inspection apparatus <NUM> according to an embodiment of the present disclosure. Referring to <FIG>, the inspecting apparatus <NUM> includes a frame <NUM> that can be attached to the inspection system <NUM>, and a verification reference body <NUM> formed on the frame <NUM>. In an embodiment, the verification reference body <NUM> may be disposed in a concave portion of the frame <NUM> as shown in <FIG>, however the verification reference body <NUM> is not limited thereto. For example, the verification reference body <NUM> may be disposed on the frame <NUM>.

The verification reference body <NUM> includes a first verification target <NUM>, a second verification target <NUM>, and a third verification target <NUM>.

The first verification target <NUM> is a verification target that indicates a height reference for verifying light radiated from the inspection unit <NUM> and a reference plane for measuring height of the inspection unit <NUM>. The first verification target <NUM> includes a flat plate 321b having a flat area 321a that indicates the height reference. Also, the flat area 321a can indicate one or more gray level (e.g., gray) or a color including one or more gray level.

The second verification target <NUM> is a verification target for verifying the accuracy of movement of the inspection unit <NUM>. That is, the second verification target <NUM> is a verification target for verifying whether the inspection unit <NUM> moves accurately to a predetermined position. The second verification target <NUM> includes at least two fiducial markers representing at least two positions for verifying the accuracy of movement of the inspection unit <NUM>. As one example, the second verification target <NUM> includes a first fiducial marker 322a, a second fiducial marker 322b, and a third fiducial marker 322c, as shown in <FIG>. The first to third fiducial markers 322a to 322c are markers for verifying the movement of the inspection unit <NUM>, and in detail, the first to third fiducial markers 322a to 322c are markers for verifying X and Y offset or X, Y, and Z skew. As another example, the second verification target <NUM> may include two fiducial markers and the two fiducial markers may be disposed in parallel with the longitudinal direction of the frame <NUM> or may be disposed at different positions.

The third verification target <NUM> is a verification target for verifying the accuracy of height measurement of the inspection unit <NUM>. The third verification target <NUM> includes at least one height target having a predetermined height for verifying the accuracy of height measurement of the inspection unit <NUM>. For example, the third verification target <NUM> includes a first height target 323a having a first height and a second height target 323b having a second height, as shown in <FIG>.

In an embodiment, the second verification target <NUM>, that is, the at least two fiducial markers may be disposed around the flat area 321a. Further, the third verification target <NUM>, that is, the at least one height marker may be disposed around the flat area 321a.

In another embodiment, the flat area 321a may be defined by the second verification target <NUM>, that is, the at least two fiducial markers. Further, the third verification target <NUM>, that is, the height marker may be disposed around the flat area 321a.

Optionally, the verification reference body <NUM> may further include a reflector <NUM>. The reflector <NUM> is a verification target for verifying whether the light source that generates light in the inspection unit <NUM> has a fault. That is, the reflector <NUM> is a verification target for verifying whether the second lighting portion <NUM> that generates the color light in the inspection unit <NUM> has a fault. The reflector <NUM> may have various shapes to reflect the color light radiated from the inspection unit <NUM>. As one example, the reflector <NUM> may have a convex curve shape, as shown in <FIG>. As another example, the reflector <NUM> may have a concave curve shape, as shown in <FIG>.

The inspection apparatus <NUM> further includes a cover <NUM>. The cover <NUM> opens the verification reference body <NUM> while a fault of the inspection unit <NUM> is verified, and covers the verification reference body <NUM> to prevent dirt, dust or the like from entering the verification reference body <NUM> while a defect of the inspection unit <NUM> is not verified.

The inspection apparatus <NUM> further includes a driving unit <NUM>. The driving unit <NUM> moves the cover <NUM> with respect to the verification reference body <NUM> to open and close the verification reference body <NUM>. That is, when the verification of a fault of the inspection unit <NUM> is started, the driving unit <NUM> moves the cover, which is over the verification reference body <NUM>, to a predetermined position to open the verification reference body <NUM>. For example, the driving unit <NUM> moves the cover <NUM>, which is over the verification reference body <NUM>, to a predetermined position (<NUM> degrees rotated position), as shown in <FIG>. Further, when the verification of a fault of the inspection unit <NUM> is completed, the driving unit <NUM> moves the cover <NUM>, which is at the predetermined position, over the verification reference body <NUM> to cover the verification reference body <NUM>, as shown in <FIG>. In an embodiment, the driving unit <NUM> includes a rotating unit that rotates the cover <NUM> by a predetermined angle (e.g., <NUM> degrees) to open and close the verification reference body <NUM>. In another embodiment, the driving unit <NUM> includes a sliding unit that slides the cover <NUM> to open and close the verification reference body <NUM>.

The inspection apparatus <NUM> further includes a stopper <NUM>. The stopper <NUM> supports the cover <NUM> to maintain the cover <NUM>, which is moved by the driving unit <NUM>, over the verification reference body <NUM>.

Referring back to <FIG>, the inspection system <NUM> further includes a controller <NUM>. In addition, the inspection system <NUM> may further include a storage unit (not shown), a user input unit (not shown), and an output unit (not shown). In an embodiment, the user input unit may include a keyboard, mouse or the like, and the output unit may include a display unit, a speaker or the like, however they are not limited thereto.

The controller <NUM> positions the inspection unit <NUM> over the inspection apparatus <NUM>, obtains image data of the verification reference body <NUM> through the inspection unit <NUM>, verifies whether the inspection unit <NUM> has a fault, and generates a verification result indicating whether the inspection unit <NUM> has a fault. Further, the controller <NUM> corrects the fault of the inspection unit <NUM> by calibrating the inspection unit <NUM> based on the generated verification result. In addition, the controller <NUM> controls the movement of each component of the inspection system <NUM>, for example, the inspection unit <NUM>, the moving unit <NUM>, and the driving unit <NUM>. In an embodiment, the controller <NUM> automatically performs the verification whether the inspection unit <NUM> has a fault in accordance with predetermined information. As one example, the predetermined information may include an inspection defect rate of the inspected body B. In this case, the controller <NUM> checks the inspection defect rate of the inspected body B, and automatically performs the verification whether the inspection unit <NUM> has a fault when the inspection defect rate of the inspected body B exceeds a predetermined threshold value. As another example, the predetermined information may include cycle information. The cycle information is information indicating the cycle of automatically verifying whether the inspection unit <NUM> has a fault. For example, the cycle information includes a cycle of every week, every second week, every month, every second month, or the like.

Although the controller <NUM> positions the inspection unit <NUM> over the inspection apparatus <NUM> in accordance with predetermined information in the embodiment described above, the present disclosure is not limited thereto, and the controller <NUM> may position the inspection unit <NUM> over the inspection apparatus <NUM> in accordance with user input information requesting the fault verification of the inspection unit <NUM>. In this case, the controller <NUM> may determine whether the inspected body B is present on the moving unit <NUM> of the inspection system <NUM>, and may position the inspection unit <NUM> over the inspection apparatus <NUM> in accordance with the user input information if it is determined that the inspected body B is not present on the moving unit <NUM>.

In an embodiment, the controller <NUM> generates a control signal for driving the driving unit <NUM>. For example, the controller <NUM> generates a first control signal for driving the driving unit <NUM> in accordance with predetermined information, and outputs the first control signal to the driving unit <NUM>. Accordingly, the driving unit <NUM> moves the cover <NUM> in response to the first control signal from the controller <NUM>, whereby the verification reference body <NUM> is opened. Further, when the verification whether the inspection unit <NUM> has a fault is completed, the controller <NUM> generates a second control signal for driving the driving unit <NUM>, and outputs the second control signal to the driving unit <NUM>. Accordingly, the driving unit <NUM> moves the cover <NUM> over the verification reference body <NUM> in response to the second control signal from the controller <NUM>. Thereby the verification reference body <NUM> is closed to prevent dirt, dust or the like from entering the verification reference body <NUM>.

In an embodiment, the controller <NUM> obtains the image data of the verification reference body <NUM> through the inspection unit <NUM> moved over the inspection apparatus <NUM>, and verifies whether the inspection unit <NUM> has a fault based on the obtained image data.

As one example, the controller <NUM> positions the inspection unit <NUM> over the first verification target <NUM>, generates a control signal for driving the inspection unit <NUM> and outputs the control signal to the inspection unit <NUM>. Accordingly, the inspection unit <NUM> obtains the image data of the first verification target <NUM> by radiating light (color light or pattern light) towards the first verification target <NUM> and receiving light reflected from the first verification target <NUM>, in response to the control signal from the controller <NUM>. The controller <NUM> verifies whether the inspection unit <NUM> has a fault based on the image data of the first verification target <NUM> obtained through the inspection unit <NUM>. That is, the controller <NUM> verifies the accuracy of the amount of light, the setting of the reference plane, and the movement amount of the pattern of the inspection unit <NUM> based on the image data of the first verification target <NUM>.

As another example, the controller <NUM> positions the inspection unit <NUM> over the second verification target <NUM>, generates a control signal for driving the inspection unit <NUM> and outputs the control signal to the inspection unit <NUM>. Accordingly, the inspection unit <NUM> obtains image data of the second verification target <NUM> by radiating light (color light or pattern light) towards the second verification target <NUM> and receiving light reflected from the second verification target <NUM>, in response to the control signal from the controller <NUM>. That is, the inspection unit <NUM> obtains image data corresponding to each of the at least two fiducial markers. The controller <NUM> verifies whether the inspection unit <NUM> has a fault based on the image data of the second verification target <NUM> obtained through the inspection unit <NUM>. That is, the controller <NUM> verifies the accuracy of movement of the inspection unit <NUM> based on the image data of the second verification target <NUM>.

As yet another example, the controller <NUM> positions the inspection unit <NUM> over the third verification target <NUM>, generates a control signal for driving the inspection unit <NUM> and outputs the control signal to the inspection unit <NUM>. Accordingly, the inspection unit <NUM> obtains image data of the third verification target <NUM> by radiating light (color light or pattern light) towards the third verification target <NUM> and receiving light reflected by the third verification target <NUM>, in response to the control signal from the controller <NUM>. The controller <NUM> verifies whether the inspection unit <NUM> has a fault based on the image data of the third verification target <NUM> obtained through the inspection unit <NUM>. That is, the controller <NUM> verifies the accuracy of the height measurement of the inspection unit <NUM> based on the image data of the third verification target <NUM>.

<FIG> is a flowchart showing a process of automatically verifying whether the inspection unit <NUM> has a fault and performing calibration through the second verification target <NUM> according to an embodiment of the present disclosure. Referring to <FIG>, while performing an inspection process (e.g., a PCB inspection process) of the inspected body B, the controller <NUM> stops the inspection process of the inspected body B when a verification cycle is reached in accordance with predetermined information (e.g., predetermined verification cycle), and positions the inspection unit <NUM> over the second verification target <NUM> based on the predetermined reference position information of the second verification target <NUM> (S602). At this time, the verification reference body <NUM> is in an open state. The controller <NUM> generates a reference input value (S604), and outputs the generated reference input value to the inspection unit <NUM> (S606). The reference input value may be an input value for driving the inspection unit <NUM>, and may be an input value for controlling the generation of the pattern light, the radiation of the pattern light, the reception of the reflected pattern light, and the acquisition of image data of the inspection unit <NUM>. However, the reference input value is not limited thereto. Accordingly, the inspection unit <NUM> obtains image data of the verification reference body <NUM> by generating light, radiating the light towards the verification reference body <NUM> and receiving light reflected from the verification reference body <NUM> in accordance with the reference input value from the controller <NUM> (S608). For example, the inspection unit <NUM> obtains image data (hereafter, referred to as "first image data") of the verification reference body <NUM> including the first fiducial marker 322a by radiating the light towards the verification reference body <NUM> and receiving the light reflected from the verification reference body <NUM>, in a state in which the inspection unit <NUM> is positioned over the first fiducial marker 322a of the second verification target <NUM>. Next, the inspection unit <NUM> obtains image data (hereafter, referred to as "second image data") of the verification reference body <NUM> including the second fiducial marker 322b by radiating the pattern light towards the verification reference body <NUM> and receiving the pattern light reflected from the verification reference body <NUM>, in a state in which the inspection unit <NUM> is positioned over the second fiducial marker 322b of the second verification target <NUM>, according to the control of the controller <NUM>. Next, the inspection unit <NUM> obtains image data (hereafter, referred to as "third image data") of the verification reference body <NUM> including the third fiducial marker 322c by radiating the pattern light towards the verification reference body <NUM> and receiving the pattern light reflected from the verification reference body <NUM>, in a state in which the inspection unit <NUM> is positioned over the third fiducial marker 322c of the second verification target <NUM>, according to the control of the controller <NUM>.

The controller <NUM> compares the image data (i.e., the image data of the verification reference body <NUM>) provided from the inspection unit <NUM> with predetermined reference data (S610), and verifies whether the inspection unit <NUM> has a fault (S612). For example, the controller <NUM> compares the first image data with the predetermined reference data, and verifies whether there is an error between the position of the first fiducial marker 322a in the first image data and the position of the first fiducial marker 322a in the predetermined reference data. Further, the controller <NUM> compares the second image data with the predetermined reference data, and verifies whether there is an error between the position of the second fiducial marker 322b in the second image data and the position of the second fiducial marker 322b in the predetermined reference data. In addition, the controller <NUM> compares the third image data with the predetermined reference data, and verifies whether there is an error between the position of the third fiducial marker 322c in the third image data and the position of the third fiducial marker 322c in the predetermined reference data.

If it is determined that the inspection unit <NUM> has no fault (i.e., the inspection unit <NUM> is normal) in step S612, the controller <NUM> generates a first verification result indicating that the inspection unit <NUM> is normal (S614), and outputs the first verification result through the output unit of the inspection system <NUM> (S616). In an embodiment, the first verification result information may include a verification result value of the inspection unit <NUM>. Further, the first verification result may be output in various forms (e.g., text, sound or the like).

Meanwhile, if it is determined that the inspection unit <NUM> has a fault in step S612, the controller <NUM> performs the calibration of the inspection unit <NUM> based on the image data of the second verification target <NUM> and the predetermined reference data (S618). For example, the controller <NUM> performs the calibration of the inspection unit <NUM> to correct the error between the positions of the first to third fiducial markers 322a to 322c in the image data of the second verification target <NUM> and the positions of the first to third fiducial markers 322a to 322c in the predetermined reference data.

Further, the controller <NUM> may generate second verification result information indicating that the inspection unit <NUM> has a fault (S620), and may output the second verification result information through the output unit (S622). In an embodiment, the second verification result information may include a verification result value of the inspection unit <NUM>. Further, the second verification result information may be output in various forms (e.g., text, sound or the like).

The controller <NUM> verifies whether the inspection unit <NUM> has a fault (fault in regard to height measurement, amount of the pattern light, degree of movement of the pattern light, and reference plane) by performing the process similar to the process shown in <FIG> on the first verification target <NUM> and the third verification target <NUM>, and may perform the calibration of the inspection unit <NUM>, depending on whether the inspection unit <NUM> has a fault.

Meanwhile, if it is verified that the inspection unit <NUM> has a fault in step S612 in accordance with the set method, the process goes to steps S620 and S622, and the second verification result may be output through the output unit.

<FIG> is a flowchart showing a process of verifying whether the inspection unit <NUM> has a fault through the reflector <NUM> according to an embodiment of the present disclosure. Referring to <FIG>, the controller <NUM> positions the inspection unit <NUM> over the reflector <NUM> based on predetermined reference position information of the reflector <NUM> (S702). In an embodiment, the controller <NUM> may position the inspection unit <NUM> over the reflector <NUM> after stopping the inspection process which is running in accordance with predetermined information (e.g., the predetermined verification cycle), or before or after verifying whether the inspection unit <NUM> has a fault using any one of the first to third verification targets <NUM> to <NUM>.

The controller <NUM> generates a reference input value for driving the inspection unit <NUM> (S704), and outputs the generated reference input value to the inspection unit <NUM> (S706). The reference input value may be an input value for driving the inspection unit <NUM>, and may be an input value for controlling the generation of the color light, the radiation of the color light, the reception of the reflected color light, and the acquisition of the image data of the inspection unit <NUM>. However, the reference input value is not limited thereto. Accordingly, the inspection unit <NUM> obtains image data of the reflector <NUM> by radiating the color light towards the reflector <NUM> and receiving the color light reflected from the reflector <NUM>, in accordance with the reference input value from the controller <NUM>. For example, when the inspection unit <NUM> is equipped with light emitting elements 221b and 22b of white, red, green, blue or the like, the controller <NUM> may position the inspection unit <NUM> at a position where each color light can be radiated towards the reflector <NUM> through the control of the X, Y and Z axes, and then may obtain the image data radiated towards the reflector <NUM> by controlling the emission of each color light.

The controller <NUM> compares the image data (i.e., the image data of the reflector <NUM>) provided by the inspection unit <NUM> with predetermined reference data (S710), and verifies whether the inspection unit <NUM> has a fault (S712). For example, the controller <NUM> compares the image data of the reflector <NUM> with the predetermined reference data of the reflector <NUM>, and determines whether the light emitting elements 221b and 222b of the second lighting portion <NUM> of the inspection unit <NUM> are all normal as shown in <FIG>, or whether some of the light emitting elements 221b and 222b of the second lighting portion <NUM> of the inspection unit <NUM> are abnormal as shown in <FIG>.

If it is verified in step S712 that the inspection unit <NUM> has no fault (i.e., it is verified that the light sources (i.e., the first light emitting element 221b or the second light emitting element 222b) of the second lighting portion <NUM> are normal), the controller <NUM> generates a first verification result indicating that the inspection unit <NUM> is normal (S714), and outputs the generated first verification result through the output unit (S716). The first verification result information may be output in various forms (e.g., text, sound or the like).

Meanwhile, if it is verified in step S712 that the inspection unit <NUM> has a fault (i.e., it is verified that at least one of the light sources (i.e., the first light emitting element 221b or the second light emitting element 222b) of the second lighting portion <NUM> is abnormal), the controller <NUM> generates a second verification result indicating that the inspection unit <NUM> is abnormal (S718), and outputs the generated second verification result through the output unit (S720). The second verification result may be output in various forms (e.g., text, sound or the like).

<FIG> is a flowchart showing a process of providing a verification result in accordance with an embodiment of the present disclosure. Referring to <FIG>, the controller <NUM> automatically verifies whether the inspection unit <NUM> has a fault in accordance with predetermined information (e.g., the predetermined verification cycle) (S902), and generates the verification result (the first verification result information or the second verification result information) (S904). As one example, the first verification result may include a verification result indicating "good" or "warning" of the inspection unit <NUM>, and the second verification result may include a verification result indicating "bad" of the inspection unit <NUM>. As another example, the first verification result may include a verification result indicating "good" of the inspection unit <NUM>, and the second verification result may include a verification result indicating "warning" or "bad" of the inspection unit <NUM>.

The controller <NUM> stores the generated verification results in the storage unit of the inspection system <NUM>. In an embodiment, the controller <NUM> may sequentially store the verification results in the storage unit of the inspection system <NUM> together with verification date/time information indicating the verification date/time of the inspection unit <NUM>.

The controller <NUM> determines whether an instruction condition for generating a list of verification results (hereafter, referred to as "list generation instruction condition") is satisfied (S908). For example, the list generation instruction condition may include input information from a user or a predetermined time cycle. In an embodiment, the controller <NUM> determines whether input information for requesting a list of the verification results is received from a user through the user input unit of the inspection system <NUM>. In another embodiment, the controller <NUM> determines whether the predetermined time cycle is reached.

If it is determined in step S908 that the list generation instruction condition is satisfied, the controller <NUM> searches the storage unit of the inspection system <NUM> (S910), generates a list of the verification results stored in the storage unit of the inspection system <NUM> (S912) and displays the generated list through the output unit of the inspection system <NUM> (S914). For example, the controller <NUM> may generate and display the list <NUM> of verification results as shown in <FIG>. In <FIG>, reference numeral <NUM> indicates an input window for selecting the number of verification results to be shown as a chart in the list <NUM> of verification results, reference numeral <NUM> indicates a first input button for showing the verification results corresponding to the number inputted into the input window <NUM> as a chart, and reference numeral <NUM> indicates a second input button for showing at least one verification result selected by a user through the user input unit as a chart.

The controller <NUM> determines whether input information for requesting display of a chart of verification results (hereafter, referred to as "chart display request information") is received from a user through the user input unit of the inspection system <NUM> (S916). For example, the chart display request information includes information of selecting a verification result and information of selecting (e.g., clicking) the first input button <NUM> or the second input button <NUM>. If it is determined in step S916 that the chart display request information is received, the controller <NUM> generates the chart of verification result information based on the verification result information corresponding to the chart display request information (S918), and displays the generated chart through the output unit of the inspection system <NUM>. For example, the controller <NUM> may generate a chart <NUM> of the verification result information based on the verification result information corresponding to the chart display request information, as shown in <FIG>. In <FIG>, reference numeral <NUM> indicates a fault limit, that is, an error limit, reference numeral <NUM> indicates a warning limit, reference numeral <NUM> indicates a reference value, and reference numeral <NUM> indicates the verification result information. Further, in <FIG>, the horizontal axis of the chart <NUM> is an index of the list of the verification result information and the vertical axis is a verification result value of the verification result information.

Claim 1:
A method of verifying whether an inspection unit (<NUM>), capable of inspecting a defect of an inspected body, in an inspection system (<NUM>) has a fault, the method comprising:
providing a verification reference body (<NUM>) formed on a frame (<NUM>) attached to the inspection system (<NUM>), the verification reference body (<NUM>) comprising:
first verification target (<NUM>) including a flat plate (321b) having a flat area (321a) capable of indicating a height reference for verifying light radiated from the inspection unit (<NUM>), a reference plane for measuring height of the inspection unit (<NUM>) and a gray level;
second verification target (<NUM>) including at least two fiducial markers (322a, 322b, 322c) indicating at least two positions for verifying an accuracy of movement of the inspection unit (<NUM>); and
third verification target (<NUM>) having a predetermined height for verifying an accuracy of height measurement of the inspection unit (<NUM>);
positioning the inspection unit (<NUM>) over the verification reference body (<NUM>);
obtaining image data of the first verification target (<NUM>) through the inspection unit (<NUM>);
verifying whether the inspection unit (<NUM>) has a fault in an accuracy of an amount of light, setting of the reference plane, and a movement amount of a pattern of the inspection unit (<NUM>) based on the image data of the first verification target (<NUM>);
obtaining image data of the second verification target (<NUM>) through the inspection unit (<NUM>), the image data of the second verification target (<NUM>) corresponding to each of the at least two fiducial markers (322a, 322b, 322c);
verifying whether the inspection unit (<NUM>) has a fault in the accuracy of movement by comparing the positions of the at least two fiducial markers (322a, 322b, 322c) in the obtained image data of the second verification target (<NUM>) with predetermined reference data;
obtaining image data of the third verification target (<NUM>) through the inspection unit (<NUM>);
verifying whether the inspection unit (<NUM>) has a fault in the accuracy of height measurement by comparing the obtained image data of the third verification target (<NUM>) with predetermined reference data; and
generating a verification result indicating whether the inspection unit (<NUM>) has a fault.