Signal distributor and inspection device

Abstract

To enable a trigger signal to appropriately be transmitted to and received by between multiple signal sources and multiple light sources while suppressing the number of signal distributors.SOLUTION: A signal distributor 10 comprises: multiple input terminals 11 including a first input terminal 11a connected to a first board 71 and a second input terminal 11b connected to a second board 72 among multiple signal sources S; multiple output terminals 12 including a first output terminal 12a connected to a first light source 31 and a second output terminal 12b connected to a second light source 32 among multiple light sources L; a first circuit C1 in which the first input terminal 11a is connected to the first output terminal 12a and at least the second input terminal 11b is separated from the first output terminal 12a among the multiple input terminals 11; and a second circuit C2 in which the second input terminal 11b is connected to the second output terminal 12b and at least the first input terminal 11a is separated from the second output terminal 12b among the multiple input terminals 11.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present disclosure relates to a signal distributor and an inspection device.

Background Art

[0002] For example, a large number of semiconductor elements such as large-scale integrated circuits are manufactured on a wafer. After the manufacturing process is completed, so-called appearance inspection is performed on each semiconductor element on the wafer. By this appearance inspection, defects such as pattern defects and foreign matters are detected. The quality of each chip is determined based on the presence or absence of defects.

[0003] Patent Document 1 discloses an inspection device (automatic appearance inspection device) for performing appearance inspection of a substrate. Specifically, the inspection device disclosed in Patent Document 1 includes a light source (light source unit) that emits stroboscopic light, a moving stage unit that moves a stage (mounting table) on which the substrate is placed, and an imaging unit that images the substrate.

[0004] The inspection device described in Patent Document 1 repeatedly emits light from the light source at a predetermined feed pitch in cooperation with the movement of the stage. Further, this inspection device synchronizes the imaging by the imaging unit with the light emission of the light source. As a result, an imaging image is output at every predetermined feed pitch.

[0005] Also, for example, as disclosed in Patent Document 2, it is also known to magnify and image a defect detected by appearance inspection using another review device. In the review device, an image of a portion determined to be a defect is magnified and imaged based on the position information of the defect detected by the appearance inspection device. Thereby, the details of the defect can be analyzed. Also, a device similar to such a review device may be incorporated into the above-described inspection device and operated (in this case, it is called a review device).

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0007] As described in the above Patent Document 1, in order to synchronize the movement of the stage and the light emission of the light source, it is conceivable to output a trigger signal from a controller (for example, a control board) for controlling the movement of the stage and input it to the light source.

[0008] However, it is also conceivable to cause the light source as described above to emit light at a timing independent of the movement of the stage or to emit light in synchronization with imaging in the review device. In order to realize the latter configuration, for example, it may be conceivable to input a trigger signal to the light source not only from the imaging unit for appearance inspection but also from the review device.

[0009] In addition, it is also conceivable to count the trigger signal for use in controlling an inspection device or the like. In order to count the trigger signal, for example, it may be conceivable to distribute the trigger signal output from the controller to the light source and the counter.

[0010] Under such circumstances, it has been a common practice to connect a so-called signal distributor having an OR circuit or the like between a signal source such as a controller and a review device and the light source.

[0011] On the other hand, the inventors of the present application have tried to shorten the light emission cycle of the light source in order to increase the inspection speed by the inspection device. However, in the case of a general light source, there is a limit to shortening its cycle.

[0012] Therefore, the inventors of the present application came up with a way to shorten the cycle time for the entire plurality of light sources by providing a plurality of light sources for one inspection device and configuring each light source to emit light at different timings (for example, alternately).

[0013] However, considering the above circumstances, when a plurality of light sources are provided, a plurality of signal sources and signal distributors must also be used respectively. When using a plurality of signal distributors, compared with the case of using a single signal distributor, there can be inconveniences from various viewpoints, such as ensuring installation space, cost increase, complication of cable wiring work related to input / output, and thus work mistakes associated with such complication.

[0014] The present disclosure has been made in view of such points, and its object is to appropriately transmit and receive trigger signals between a plurality of signal sources and a plurality of light sources while suppressing the number of signal distributors.

Means for Solving the Problem

[0015] The present disclosure relates to a signal distributor that is connected between a plurality of signal sources each outputting a trigger signal and a plurality of light sources each emitting light based on the trigger signal, and distributes and outputs the trigger signal input from each of the plurality of signal sources to each of the plurality of light sources.

[0016] According to the present disclosure, the signal distributor is connected to the plurality of signal sources, and includes a first input terminal connected to a first signal source among the plurality of signal sources, and a signal source other than the first signal source, a second input terminal connected to a second signal source that outputs the trigger signal at a timing different from that of the first signal source, a plurality of input terminals including the second input terminal, a plurality of output terminals connected to the plurality of light sources, a first output terminal connected to a first light source among the plurality of light sources, and a second output terminal connected to a second light source other than the first light source, a first circuit that connects the first input terminal to the first output terminal while disconnecting at least the second input terminal from the first output terminal among the plurality of input terminals, and a second circuit that connects the second input terminal to the second output terminal while disconnecting at least the first input terminal from the second output terminal among the plurality of input terminals.

[0017] According to the above configuration, the trigger signal input from the first signal source via the first input terminal causes the first light source to emit light via the first circuit, while the trigger signal input from the second signal source via the second input terminal causes the second light source to emit light via the second circuit. Thus, although it is a single signal distributor, the trigger signal can be appropriately transmitted and received between the plurality of signal sources and the plurality of light sources.

[0018] Therefore, according to the above configuration, it is possible to cause different light sources to emit light at different timings by the trigger signals input from different signal sources without increasing the number of signal distributors. As a result, it is possible to achieve both suppression of the number of signal distributors and shortening of the cycle for the entire plurality of light sources.

[0019] Further, the first and second circuits may be each connected to an output terminal that outputs the trigger signal input via any one of the first and second input terminals to a third light source other than the first and second light sources.

[0020] As an example, consider a case where one illumination is configured to be emitted by the first and second light sources. In this case, apart from the one illumination, a case where another illumination emitted by the third light source is provided is also conceivable. Depending on the use of the signal distributor, there may also be a need to simultaneously emit the one illumination and the other illumination, or to emit them individually.

[0021] In conventional knowledge, in order to meet such needs, it has been essential to provide a signal distributor dedicated to one illumination and a signal distributor dedicated to the other illumination.

[0022] On the other hand, according to the above configuration, without newly installing a signal distributor, it is possible to input a trigger signal to the third light source only by devising the output destinations of the first and second circuits. As a result, it becomes possible to simultaneously emit the one illumination and the other illumination, or to emit them individually.

[0023] Further, each of the first and second circuits may have an OR circuit that outputs a logical sum of the trigger signal input via either of the first and second input terminals and the trigger signal input via an input terminal other than the first and second input terminals.

[0024] According to the above configuration, by providing an OR circuit in each of the first and second circuits, it is possible to synchronize the emission of the one illumination and the other illumination described above. This is advantageous for simultaneously emitting the one illumination and the other illumination.

[0025] Further, each of the plurality of output terminals may individually turn on and off the output of the logical sum to the plurality of light sources based on a control signal input from the outside.

[0026] According to the above configuration, the output destination of the logical sum can be individually turned on and off. As a result, it becomes possible to realize more diverse controls such as simultaneously emitting the one illumination and the other illumination, or emitting them individually.

[0027] Further, the first and second circuits may be switched to an interlocking circuit that connects the first input terminal to both the first and second output terminals and connects the second input terminal to both the first and second output terminals based on a control signal input from the outside.

[0028] According to the above configuration, by switching the first and second circuits to an interlocking circuit, the first and second light sources can be caused to emit light simultaneously. Thereby, for example, in a situation where the amount of light is small, it becomes possible to supplement the amount of light.

[0029] The present disclosure also relates to an inspection apparatus including the signal distributor, a camera facing a target region of an object to be inspected, and a stage on which the object to be inspected is placed and that moves relative to the camera, the inspection apparatus imaging the target region by the camera while moving the stage and inspecting the object to be inspected based on an image captured by the camera.

[0030] According to the present disclosure, the first and second signal sources may be a control board that alternately outputs the trigger signal so that at least one of the plurality of light sources illuminates the target region in synchronization with imaging by the camera.

[0031] Here, the term "synchronization" is used in a broad sense in the present disclosure. That is, in the present disclosure, it is only necessary to output a trigger signal during imaging by the camera, and it is not necessary for the imaging timing by the camera and the output timing of the trigger signal to be exactly the same time.

[0032] According to the above configuration, the emission interval of the light source in the inspection apparatus can be made as short as possible.

Effects of the Invention

[0033] According to the present disclosure, it is possible to appropriately transmit and receive a trigger signal between a plurality of signal sources and a plurality of light sources while suppressing the number of signal distributors.

Brief Description of the Drawings

[0034]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

DETAILED DESCRIPTION OF THE INVENTION

[0035] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. Note that the following description is illustrative.

[0036] FIG. 1 is a schematic diagram illustrating the configuration of the inspection apparatus 1. This inspection apparatus 1 is a system for imaging the appearance of the wafer W as an object to be inspected and detecting defects of the wafer W based on the imaging result. Here, the “defects” include foreign matters, scratches, edge lint defects, through-hole abnormalities, coating unevenness, peeling, scratches, bonding pad abnormalities, color unevenness, pattern abnormalities, stains, discoloration, deformation, etc.

[0037] <Overall Configuration of the Inspection Apparatus 1> As shown in FIG. 1, the inspection apparatus 1 according to the present embodiment includes, as elements related to the appearance inspection and review inspection of the wafer W, an inspection camera 2, a first lighting unit 3, a second lighting unit 4, a stage 5, a review camera 6, a first computer 7, a second computer 8, a PLC 9, and a signal distributor 10.

[0038] Further, the first computer 7 has a first board 71, a second board 72, and a third board 73 as control boards related to the inspection camera 2, the first lighting unit 3, the second lighting unit 4, and the stage 5. Similarly, the second computer 8 has a fourth board 81 as a control board related to the inspection camera 2, the first lighting unit 3, and the second lighting unit 4.

[0039] In this embodiment, the first board 71, the second board 72, the third board 73, the fourth board 81, and the review camera 6 each function as a signal source S that outputs a trigger signal. As will be described later, among these signal sources S, at least the first board 71 and the second board 72 output trigger signals at different timings.

[0040] The first lighting unit 3 has a first light source 31 and a second light source 32 as light sources for causing the first lighting unit 3 to emit light. Similarly, the second lighting unit 4 has a third light source 41 as a light source for causing the second lighting unit 4 to emit light.

[0041] In this embodiment, the first light source 31, the second light source 32, and the third light source 41 each function as a light source L that emits light based on a trigger signal. Among these light sources L, at least the first light source 31 and the second light source 32 can emit light at different timings or at the same timing.

[0042] The signal distributor 10 is connected between a plurality of signal sources S and a plurality of light sources L. As will be described later, the signal distributor 10 according to this embodiment distributes and outputs the trigger signal input from each of the plurality of signal sources S to each of the plurality of light sources L. Although there is only one signal distributor 10, by distributing the trigger signal input from each signal source S, the first light source 31 and the second light source 32 can be caused to emit light alternately. Here, the trigger signal is a pulsed signal.

[0043] Hereinafter, each element constituting the inspection apparatus 1 will be described in order.

[0044] <Inspection Camera 2> Inspection Camera 2 is a camera facing the target area A on the wafer W. Inspection Camera 2 images the surface of the wafer W. The image captured by Inspection Camera 2 is used to detect defects formed on the wafer W. Note that the target area A in the present embodiment refers to a plurality of areas partitioned on the wafer W. Each target area A may be an area where a circuit pattern is manufactured.

[0045] Specifically, Inspection Camera 2 according to the present embodiment includes an objective lens 21, a lens barrel 22, a half mirror 23, and an image sensor 24. This Inspection Camera 2 is fixed at a fixed position. Inspection Camera 2 is an example of the "camera" in the present embodiment.

[0046] The objective lens 21 is fixed at a fixed position facing the wafer W. The objective lens 21 is configured to collect the light (reflected light) reflected on the surface of the wafer W and then guide it into the lens barrel 22.

[0047] The lens barrel 22 is a cylindrical body with the objective lens 21 attached to its tip. Inside the lens barrel 22, a half mirror 23 is accommodated. The half mirror 23 transmits the reflected light and guides it to the image sensor 24.

[0048] The image sensor 24 receives the reflected light (see the optical axis L1 in FIG. 1). When the image sensor 24 is irradiated with the reflected light, the image sensor 24 generates an electrical signal corresponding to the reflected light and guides it to the second computer 8.

[0049] <First Lighting Unit 3> When imaging with Inspection Camera 2 or Review Camera 6, the First Lighting Unit 3 emits illumination light to the surface of the wafer W, particularly the target area A. The First Lighting Unit 3 is coaxial illumination in which the optical axis L2 of the illumination light is made coaxial with the optical axis L1 of the reflected light incident on the image sensor 24. Further, the First Lighting Unit 3 has a configuration including a plurality of light sources while being one coaxial illumination.

[0050] Specifically, in addition to the first light source 31 and the second light source 32 according to this embodiment, the first lighting unit 3 further has a light guide unit 33. This first lighting unit 3 is connected to the lens barrel 22 of the inspection camera 2.

[0051] The first light source 31 is connected to a plurality of signal sources S via the signal distributor 10. When a pulsed trigger signal is input from each signal source S, the first light source 31 emits light based on the trigger signal. The illumination light generated by this light emission is guided to the light guide unit 33 via an optical cable or the like. This illumination light is used as a strobe for imaging.

[0052] The second light source 32 is connected to a plurality of signal sources S via the signal distributor 10. When a pulsed trigger signal is input from each signal source S, the second light source 32 emits light based on the trigger signal. The illumination light generated by this light emission is guided to the light guide unit 33 via an optical cable or the like, similar to the illumination light from the first light source 31. This illumination light is used as a strobe for imaging, similar to the illumination light from the first light source 31.

[0053] The first light source 31 and the second light source 32 may each be a xenon lamp, an LED illumination, a laser diode, or a metal halide lamp. In this embodiment, both the first light source 31 and the second light source 32 are constituted by xenon lamps.

[0054] Also, due to design constraints, an upper limit of the emission frequency is defined for the first light source 31 and the second light source 32. The upper limit of the emission frequency is set, for example, to 50 Hz or more and 250 Hz or less, preferably 100 Hz or more and 200 Hz or less.

[0055] If the upper limit of the emission frequency is set to 150 Hz, for example, the first light source 31 and the second light source 32 can each emit light at intervals of about 6.67 milliseconds at the shortest.

[0056] The light guide unit 33 is connected to the side of the lens barrel 22 and is optically connected to each of the first light source 31 and the second light source 32 via an optical cable or the like. When at least one of the first light source 31 and the second light source 32 emits light, the light guide unit 33 guides the illumination light generated by the emission to the half mirror 23. The half mirror 23 reflects the illumination light guided from the light guide unit 33 and guides it to the wafer W via the objective lens 21.

[0057] <Second illumination unit 4> When imaging is performed by the inspection camera 2 or the review camera 6, the second illumination unit 4 emits illumination light to the surface of the wafer W, particularly to the target area A. The second illumination unit 4 is oblique illumination in which the optical axis L3 of the illumination light is inclined with respect to the optical axis L1 of the reflected light incident on the imaging element 24.

[0058] The second illumination unit 4 according to the present embodiment has the third light source 41 as described above. The second illumination unit 4 is fixed at a fixed position away from the inspection camera 2.

[0059] The third light source 41 is connected to a plurality of signal sources S via the signal distributor 10. When a pulsed trigger signal is input from each signal source S, the third light source 41 emits light based on the trigger signal. The illumination light generated by this emission is emitted via an optical cable or the like. This illumination light is used as a strobe for imaging, similarly to the illumination light emitted from the first and second light sources 31 and 32.

[0060] The third light source 41 may be a xenon lamp, an LED illumination, a laser diode, or a metal halide lamp. In the present embodiment, the third light source 41 is constituted by a xenon lamp.

[0061] <Stage 5> On stage 5, a wafer W to be inspected is placed. Stage 5 moves relative to inspection camera 2. The moving direction of stage 5 is, for example, the horizontal direction. By moving stage 5 relative to inspection camera 2, the target area A that inspection camera 2 faces can be changed. Thereby, the target area A to be inspected for defects can be switched in order.

[0062] <Review camera 6> Review camera 6 is a camera that images defects detected on wafer W. The image captured by review camera 6 is used to analyze in detail the defects on wafer W.

[0063] <First computer 7> First computer 7 is configured to execute processes related to the operation of inspection apparatus 1 by transmitting and receiving signals to and from each part of inspection apparatus 1. First computer 7 includes a CPU, a memory, and an input / output bus. First computer 7 can also be called a "host computer".

[0064] First computer 7 is connected to stage 5 via a cable (not shown). When detecting a defect with inspection camera 2, first computer 7 outputs a control signal and inputs the control signal to stage 5 via the cable. Stage 5 moves along the horizontal direction based on the control signal input from first computer 7.

[0065] Also, first computer 7 is connected to inspection camera 2 via a cable (not shown) and second computer 8. When detecting a defect with inspection camera 2, first computer 7 outputs a trigger signal and inputs the trigger signal to second computer 8 via the cable. This trigger signal has a pulse-shaped waveform. As will be described later, second computer 8 generates a control signal in response to the trigger signal and inputs the control signal to inspection camera 2. Inspection camera 2 images the target area A of wafer W based on the control signal input from second computer 8.

[0066] When detecting defects on the wafer W, the first computer 7 outputs a control signal and a trigger signal. The former control signal is input to the stage 5, and the latter trigger signal is input to the inspection camera 2. Thereby, the first computer 7 can image the target area A with the inspection camera 2 while moving the stage 5. Also, the first computer 7 can change the current objective lens 21 to another objective lens 21 by operating a revolver (not shown) and change the magnification at the time of imaging.

[0067] In addition, when detecting the result, the first computer 7 can properly use "line inspection" for imaging the target area A while moving the stage 5 and "step inspection" for imaging the target area A with the stage 5 temporarily stopped. In the former line inspection, the stage 5 will continue to move without stopping. In the latter step inspection, the movement and stop of the stage 5 will be repeated.

[0068] Also, the first computer 7 is connected to the review camera 6 via a cable (not shown). The first computer 7 outputs a trigger signal during the review inspection after defect detection and inputs the trigger signal to the review camera 6 via a cable or the like. This trigger signal has a pulse-shaped waveform. The review camera 6 images the target area A of the wafer W based on the trigger signal input from the first computer 7.

[0069] Also, the first computer 7 is connected to the first light source 31, the second light source 32, and the third light source 41 via the signal distributor 10. The first computer 7 outputs a trigger signal during line inspection, step inspection, and review inspection, and inputs the trigger signal to at least one of the first light source 31, the second light source 32, and the third light source 41 via the signal distributor 10. This trigger signal has a pulse-shaped waveform. At least one of the first light source 31, the second light source 32, and the third light source 41 emits light based on the trigger signal input via the signal distributor 10.

[0070] Specifically, the first computer 7 has a first board 71, a second board 72, and a third board 73 as control boards related to at least a part of the functions described above. The first board 71 is an example of the "first signal source" in the present embodiment. The second board 72 is an example of the "second signal source" in the embodiment.

[0071] The first board 71 and the second board 72 are control boards that alternately output trigger signals so that the target area A is illuminated by at least one of the plurality of light sources L in synchronization with the imaging by the inspection camera 2. Here, the second board 72 is a signal source other than the first board 71 and outputs a trigger signal at a timing different from that of the first board 71.

[0072] Specifically, the first board 71 is a control board for controlling the drive system (stepping motor, servo motor, etc.) of the stage 5. The first board 71 can also be called the "first stage board". The first board 71 outputs a control signal based on data input from the outside or data set in advance, and inputs this to the stage 5. The stage 5 moves horizontally when a control signal is input.

[0073] In addition, during line inspection, the first board 71 outputs the above-described pulsed trigger signal each time the coordinates of the stage 5 match the coordinates stored in the first computer 7. Two output ports 71a for outputting such trigger signals are provided on the first board 71 according to the present embodiment.

[0074] One output port 71a on the first board 71 is connected to the inspection camera 2 via the second computer 8. Here, if the first light source 31, the second light source 32, and the third light source 41 emit light simultaneously, the remaining one output port 71a is sufficient. However, in order to emit light from each light source at different timings, such as a case where the first light source 31 and the second light source 32 emit light alternately, two or more output ports are required.

[0075] Therefore, in this embodiment, by adding a second board 72 to the first computer 7, an output port for the light source is secured. This second board 72 is a control board configured in the same manner as the first board 71. The second board 72 can be referred to as the "second stage board".

[0076] And in this embodiment, one output port 71a on the first board 71 is connected to the inspection camera 2 as described above, and the other output port 71a is connected to the first light source 31 and the third light source 41 via the signal distributor 10 as described later. In addition, one output port 72a on the second board 72 is connected to the second light source 32 and the third light source 41 via the signal distributor 10 as also described later.

[0077] FIG. 2 is a time chart illustrating waveforms of trigger signals output from the first and second boards 71 and 72 during line inspection. (a) of FIG. 2 illustrates the waveform of the trigger signal input from the first board 71 to the second computer 8. (b) of FIG. 2 illustrates the waveform of the trigger signal input from the first board 71 to the first light source 31 via the signal distributor 10. (c) of FIG. 2 illustrates the waveform of the trigger signal input from the second board 72 to the second light source 32 via the signal distributor 10.

[0078] As shown in (a) of FIG. 2, imaging is started three times at times t11, t21, and t31, and it is assumed that imaging is executed during the periods from time t11 to time t12, from time t21 to time t22, and from time t31 to time t32, respectively.

[0079] Here, in (b) of FIG. 2, it is assumed that the first light source 31 emits light at a time interval (2×ΔT) corresponding to the upper limit of the emission frequency. In this case, with only the first light source 31, it is not possible to provide illumination light on the wafer W during the imaging from time t21 to time t22.

[0080] However, as shown in Fig. 2(c), by causing the second light source 32 to emit light alternately with the first light source 31, the entire first illumination unit 3 will emit light at time intervals (ΔT) that exceed the upper limit of the emission frequency.

[0081] In this way, by adding the second board 72 to the first computer 7, it becomes possible to input a trigger signal to the second light source 32 at a timing different from that of the first light source 31. As a result, for example, it becomes possible to cause the first light source 31 and the second light source 32 to emit light alternately, and thus, it becomes possible to provide illumination from the first illumination unit 3 at a shorter cycle. Furthermore, by making it possible to provide illumination at a shorter cycle, it becomes possible to move the stage 5 at a higher speed during line inspection. As a result, the inspection speed can be improved.

[0082] The third board 73 is a control board for controlling each part of the inspection apparatus 1 during step inspection. In the present embodiment, the third board 73 is constituted by a so-called TTL board.

[0083] Also, the third board 73 outputs a pulsed trigger signal each time the stage 5 stops during step inspection. Two output ports 73a for outputting such trigger signals are provided on the third board 73 according to the present embodiment (only one is shown in Fig. 3).

[0084] One of the output ports 73a on the third board 73 is connected to the inspection camera 2 via the second computer 8. The other output port 73a on the third board 73 is connected to the first light source 31 and the third light source 41 via a signal distributor 10, as will be described later.

[0085] That is, during step inspection, since imaging is performed with the stage 5 stopped, it is not necessary to provide illumination at as short a cycle as in line inspection. Therefore, it is also unnecessary to cause the first light source 31 and the second light source 32 to emit light alternately, and thus, it is also unnecessary to connect the third board 73 and the second light source 32.

[0086] <Second computer 8> The second computer 8 is configured to execute predetermined processes related to image processing by transmitting and receiving signals to and from each part of the inspection apparatus 1 including the first computer 7. The second computer 8 includes a CPU, a memory, and an input / output bus. The second computer 8 may also be referred to as an "image processing computer."

[0087] The second computer 8 is connected to the first computer 7. When performing line inspection, the second computer 8 receives a trigger signal as illustrated in Fig. 2(a) from the first computer 7.

[0088] The second computer 8 is also connected to the inspection camera 2 via a cable (not shown). The second computer 8 outputs a control signal in synchronization with the trigger signal input from the first computer 7 and inputs this to the inspection camera 2. As described above, the inspection camera 2 images the target area A of the wafer W based on the control signal input from the second computer 8.

[0089] The second computer 8 inspects the wafer W as the inspection target based on the image captured by the inspection camera 2. The second computer 8 diagnoses the presence or absence of defects on the wafer W.

[0090] When detecting a defect on the wafer W, the first computer 7 outputs a control signal and a trigger signal. The former control signal is input to the stage 5, and the latter trigger signal is input to the inspection camera 2. Thereby, the first computer 7 can cause the inspection camera 2 to image the target area A while moving the stage 5.

[0091] Note that, for uses other than line inspection and step inspection (for example, warm-up operation), the second computer 8 can cause the first light source 31 and the third light source 41 to emit light in any combination.

[0092] Therefore, the second computer 8 is connected to the first light source 31 and the third light source 41 via the signal distributor 10. When used for purposes other than line inspection and step inspection, the second computer 8 inputs, via the signal distributor 10, a trigger signal having a waveform similar to the signals output from the first board 71 and the second board 72, to at least one of the first light source 31 and the third light source 41.

[0093] Specifically, the second computer 8 has a fourth board 81 as a control board related to the functions described above. The fourth board 81 is a control board for executing processes related to image processing. The fourth board 81 can also be referred to as an "image processing board". The fourth board 81 analyzes the images acquired by the inspection camera 2 and diagnoses the presence or absence of defects based on the data input from the outside or the data set in advance.

[0094] In addition, when used for purposes other than line inspection and step inspection, the fourth board 81 outputs the above-described pulsed trigger signal. The fourth board 81 according to the present embodiment is provided with an output port 81a for outputting such a trigger signal (see FIG. 3).

[0095] The output port 81a of the fourth board 81 is connected to the first light source 31 and the third light source 41 via the signal distributor 10, as will be described later.

[0096] <plc9> The PLC 9 is a so-called programmable logic controller, which is configured to perform various functions. The PLC 9 includes, according to its functions, a first counter 91, a second counter 92, a third counter 93, and a circuit switching unit 94.

[0097] The first counter 91 counts the number of pulses of the trigger signal input to the first light source 31. The second counter 92 counts the number of pulses of the trigger signal input to the second light source 32. The third counter 93 counts the number of pulses of the trigger signal input to the third light source 41.

[0098] Also, the circuit switching unit 94 inputs an electrical signal (e.g., a digital signal) to the signal distributor 10 to switch the signal distributor 10 from the independent mode to the interlocking mode, switch the signal distributor 10 from the interlocking mode to the independent mode, or open and close the contacts of the signal distributor 10 (the on-off circuit 14 described later). Note that it is not essential to provide the circuit switching unit 94 in the PLC 9. The circuit switching unit 94 may be provided in the first computer 7 or the second computer 8.

[0099] <Signal distributor 10> FIG. 3 is a diagram illustrating the signal distributor 10 in the independent mode. FIG. 4 is a diagram illustrating the signal distributor 10 in the interlocking mode.

[0100] (Independent mode) As shown in FIG. 3, the signal distributor 10 in the independent mode includes a plurality of input terminals 11 connected to a plurality of signal sources S, a plurality of output terminals 12 connected to a plurality of light sources L, a first circuit C1 and a second circuit C2, and an on-off circuit 14. The first circuit C1 and the second circuit C2 are interposed between the plurality of input terminals 11 and the plurality of output terminals 12. The on-off circuit 14 is interposed between the first circuit C1 and the second circuit C2 and the plurality of output terminals 12.

[0101] The plurality of input terminals 11 are terminals to which trigger signals are respectively input. The plurality of input terminals 11 include a first input terminal 11a connected to a first signal source (the first board 71 in this embodiment) among the plurality of signal sources S, and a second input terminal 11b connected to a second signal source (the second board 72 in this embodiment) other than the first signal source.

[0102] Specifically, the plurality of input terminals 11 according to this embodiment have, in addition to the first input terminal 11a and the second input terminal 11b, a third input terminal 11c, a fourth input terminal 11d, a fifth input terminal 11e, and a sixth input terminal 11f.

[0103] As shown in FIG. 3, among these input terminals 11, the third input terminal 11c is connected to the third board 73, the fourth input terminal 11d is connected to the review camera 6, and the fifth input terminal 11e is connected to the fourth board 81.

[0104] The first input terminal 11a, the third input terminal 11c, the fourth input terminal 11d, and the fifth input terminal 11e are connected to the first circuit C1. The second input terminal 11b is connected to the second circuit C2.

[0105] The input terminals (the first input terminal 11a, the third input terminal 11c, the fourth input terminal 11d, and the fifth input terminal 11e) connected to the first circuit C1 and the input terminal (the second input terminal 11b) connected to the second circuit C2 are insulated from each other to block the transmission and reception of electrical signals.

[0106] On the other hand, the plurality of output terminals 12 are terminals that respectively distribute and output trigger signals. The plurality of output terminals 12 include a first output terminal 12a connected to a first light source 31 among the plurality of light sources L, and a second output terminal 12b connected to a second light source 32 other than the first light source 31.

[0107] Specifically, in addition to the first output terminal 12a and the second output terminal 12b, the plurality of output terminals 12 according to this embodiment include a third output terminal 12c, a fourth output terminal 12d, a fifth output terminal 12e, a sixth output terminal 12f, a seventh output terminal 12g, and an eighth output terminal 12h.

[0108] As shown in FIG. 3, among these output terminals 12, a first counter 91 is connected to the third output terminal 12c, a third light source 41 is connected to the fourth output terminal 12d, a third counter 93 is connected to the fifth output terminal 12e, a second counter 92 is connected to the sixth output terminal 12f, a third light source 41 is connected to the seventh output terminal 12g in the same manner as the fourth output terminal 12d, and a third counter 93 is connected to the eighth output terminal 12h in the same manner as the fifth output terminal 12e.

[0109] And the first circuit C1 is configured to connect the first input terminal 11a among the plurality of input terminals 11 to the first output terminal 12a while disconnecting at least the second input terminal 11b from the first output terminal 12a.

[0110] That is, as shown in FIG. 3, the first input terminal 11a is connected to the first output terminal 12a, the third output terminal 12c, the fourth output terminal 12d, and the fifth output terminal 12e via a first OR circuit 13a and a switching circuit 14 to be described later.

[0111] And the first input terminal 11a is connected to the first light source 31, the first counter 91, the third light source 41, and the third counter 93 via the first output terminal 12a, the third output terminal 12c, the fourth output terminal 12d, and the fifth output terminal 12e. However, as shown in FIG. 3, the first input terminal 11a is disconnected from the second output terminal 12b and thus not connected so as to be able to transmit and receive signals.

[0112] Therefore, the trigger signal input from the first board 71 to the first input terminal 11a can cause the first light source 31 to emit light via the first output terminal 12a, but does not contribute to the emission of the second light source 32 via the second output terminal 12b.

[0113] On the other hand, the second circuit C2 is configured to connect the second input terminal 11b among the plurality of input terminals 11 to the second output terminal 12b, while disconnecting at least the first input terminal 11a from the second output terminal 12b.

[0114] That is, as shown in FIG. 3, the second input terminal 11b is connected to the second output terminal 12b, the sixth output terminal 12f, the seventh output terminal 12g, and the eighth output terminal 12h via a second OR circuit 13b and an on-off circuit 14 described later.

[0115] And the second input terminal 11b is connected to the second light source 32, the second counter 92, the third light source 41, and the third counter 93 via the second output terminal 12b, the sixth output terminal 12f, the seventh output terminal 12g, and the eighth output terminal 12h. However, as shown in FIG. 3, the second input terminal 11b is disconnected from the first output terminal 12a and thus not connected so as to be able to transmit and receive signals to and from the first light source 31.

[0116] Therefore, the trigger signal input from the second board 72 to the second input terminal 11b can cause the second light source 32 to emit light via the second output terminal 12b, but does not contribute to the emission of the first light source 31 via the first output terminal 12a.

[0117] Specifically, the first circuit C1 and the second circuit C2 according to the present embodiment each have an OR circuit 13 that outputs a logical sum of a trigger signal input via either the first and second input terminals 11a and 11b and a trigger signal input via other input terminals other than the first and second input terminals 11a and 11b. This OR circuit 13 is composed of a first OR circuit 13a provided in the first circuit C1 and a second OR circuit 13b provided in the second circuit C2.

[0118] Specifically, as shown in FIG. 3, the first OR circuit 13a is individually connected to each of the first input terminal 11a, the third input terminal 11c, the fourth input terminal 11d, and the fifth input terminal 11e. When a trigger signal is input from at least one of the first input terminal 11a, the third input terminal 11c, the fourth input terminal 11d, and the fifth input terminal 11e, the first OR circuit 13a outputs the logical sum of the trigger signals.

[0119] The output side of the first OR circuit 13a is branched into four, and is respectively connected to the first output terminal 12a, the third output terminal 12c, the fourth output terminal 12d, and the fifth output terminal 12e.

[0120] Here, based on the control signals input from the outside, the logical sum outputs to the plurality of light sources L are individually turned on and off for each of these four output terminals 12. This on / off is switched by the on / off circuit 14.

[0121] Specifically, the on / off circuit 14 according to the present embodiment is interposed between the output side of the first OR circuit 13a and the first output terminal 12a, the third output terminal 12c, the fourth output terminal 12d, and the fifth output terminal 12e.

[0122] The on / off circuit 14 includes a first switch 14a that opens and closes the first output terminal 12a, a third switch 14c that opens and closes the third output terminal 12c, a fourth switch 14d that opens and closes the fourth output terminal 12d, and a fifth switch 14e that opens and closes the fifth output terminal 12e.

[0123] The first switch 14a, the third switch 14c, the fourth switch 14d, and the fifth switch 14e may each be constituted by a relay circuit. The first switch 14a, the third switch 14c, the fourth switch 14d, and the fifth switch 14e may each be configured to individually open and close electrical contacts based on, for example, digital signals from the PLC 9.

[0124] On the other hand, as shown in FIG. 3, the second OR circuit 13b is individually connected to each of the second input terminal 11b and the sixth input terminal 11f. When a trigger signal is input from at least one of the second input terminal 11b and the sixth input terminal 11f, the second OR circuit 13b outputs the logical sum of the trigger signals.

[0125] The output side of the second OR circuit 13b is branched into four, and is respectively connected to the second output terminal 12b, the sixth output terminal 12f, the seventh output terminal 12g, and the eighth output terminal 12h.

[0126] Similar to the first OR circuit 13a, for the four output terminals 12 in the second OR circuit 13b, based on control signals input from the outside, the output of the logical sum to the plurality of light sources L is individually turned on and off. This on / off is switched by the on / off circuit 14.

[0127] Specifically, the on / off circuit 14 according to this embodiment is interposed between the output side of the second OR circuit 13b and the second output terminal 12b, the sixth output terminal 12f, the seventh output terminal 12g, and the eighth output terminal 12h.

[0128] The on / off circuit 14 includes a second switch 14b that opens and closes the second output terminal 12b, a sixth switch 14f that opens and closes the sixth output terminal 12f, a seventh switch 14g that opens and closes the seventh output terminal 12g, and an eighth switch 14h that opens and closes the eighth output terminal 12h.

[0129] The second switch 14b, the sixth switch 14f, the seventh switch 14g, and the eighth switch 14h may each be constituted by a relay circuit. The second switch 14b, the sixth switch 14f, the seventh switch 14g, and the eighth switch 14h may be configured to individually open and close electrical contacts based on, for example, digital signals from the PLC 9.

[0130] Further, the first circuit C1 and the second circuit C2 are each connected to an output terminal 12 that outputs a trigger signal input via either the first input terminal 11a or the second input terminal 11b to a third light source 41 other than the first light source 31 and the second light source 32. In the present embodiment, the fourth input terminal 11d and the seventh input terminal 11g function as the output terminal 12 that outputs the trigger signal to the third light source 41.

[0131] Figure 4 is a table illustrating the relationship between the signal source S according to the present embodiment, the uses of the trigger signals output from the respective signal sources S, and the light sources L to which the trigger signals can be input from the respective signal sources S, in the independent mode. The check marks attached to each cell indicate that the trigger signal can be input to the light source L corresponding to each signal source S by appropriately switching the on-off circuit 14. The hyphen marks attached to each cell indicate that the trigger signal cannot be input only by switching the on-off circuit 14.

[0132] For example, the first board 71 can input a trigger signal to the first light source 31 and the third light source 41 during line inspection. On the other hand, the second board 72 can input a trigger signal to the second light source 32 and the third light source 41 during line inspection.

[0133] To achieve such input and output, at least the first switch 14a and the second switch 14b are connected during line inspection. Then, as illustrated in FIG. 2, by alternately inputting the trigger signal output from the first board 71 and the trigger signal output from the second board 72 to the signal distributor 10, the first light source 31 and the second light source 32 can be caused to emit light alternately. Thereby, as described above, the light emission interval of the first lighting unit 3 can be shortened.

[0134] Further, if necessary, the fifth switch 14e is also turned on, and the second lighting unit 4 is caused to emit light via the third light source 41, so that the first lighting unit 3 and the second lighting unit 4 can be caused to emit light simultaneously.

[0135] Also, as shown in FIG. 4, the third board 73 outputs a trigger signal during the step inspection and inputs the trigger signal to at least one of the first light source 31 and the third light source 41. To achieve such input and output, at least one of the first switch 14a and the fifth switch 14e is connected during the step inspection. As a result, it is possible to emit illumination light only from the first illumination unit 3, emit illumination light from both the first and second illumination units 3 and 4, or emit illumination light only from the second illumination unit 4.

[0136] Also, regarding the fourth board 81 and the review camera 6, it is the same as the third board 73 as shown in FIG. 4. That is, similar to the above-described step inspection, it is possible to emit illumination light only from the first illumination unit 3, emit illumination light from both the first and second illumination units 3 and 4, or emit illumination light only from the second illumination unit 4.

[0137] (Interlock mode) Also, the first circuit C1 and the second circuit C2 are configured to switch to the interlock circuit C3 based on a control signal input from the outside (for example, an electrical signal input from the PLC 9). The state of switching from the first circuit C1 and the second circuit C2 to the interlock circuit C3 corresponds to the above-described interlock mode.

[0138] The interlock circuit C3 is configured to connect the first input terminal 11a to both the first and second output terminals 12a and 12b, while connecting the second input terminal 11b to both the first and second output terminals 12a and 12b.

[0139] That is, as shown in FIG. 4, the first input terminal 11a is connected to all of the plurality of output terminals 12 via the third OR circuit 13c and the on-off circuit 14 described later. Similarly, the second input terminal 11b is connected to all of the plurality of output terminals 12 via the third OR circuit 13c and the on-off circuit 14.

[0140] The first input terminal 11a is connected to the first light source 31 via the first output terminal 12a and is also connected to the second light source 32 via the second output terminal 12b. Similarly, the second input terminal 11b is connected to the second light source 32 via the second output terminal 12b and is also connected to the first light source 31 via the first output terminal 12a.

[0141] Therefore, the trigger signal input to the first input terminal 11a from the first board 71 can contribute to both the emission of the first light source 31 via the first output terminal 12a and the emission of the second light source 32 via the second output terminal 12b.

[0142] Similarly, the trigger signal input to the second input terminal 11b from the second board 72 can contribute to both the emission of the second light source 32 via the second output terminal 12b and the emission of the first light source 31 via the first output terminal 12a.

[0143] The interlocking circuit C3 has a third OR circuit 13c that outputs the logical sum of a trigger signal input via at least one of the first and second input terminals 11a and 11b and a trigger signal input via other input terminals other than the first and second input terminals 11a and 11b.

[0144] Specifically, as shown in FIG. 4, the third OR circuit 13c is connected to all of a plurality (six in this embodiment) of input terminals 11. The third OR circuit 13c outputs the logical sum of the trigger signals when a trigger signal is input from at least one of the six input terminals 11.

[0145] The output side of the third OR circuit 13c branches into eight, and each is connected to all of a plurality (eight in this embodiment) of output terminals 12.

[0146] Here, each of the eight output terminals 12 individually turns on and off the logical sum output to the plurality of light sources L based on a control signal input from the outside. This on / off is switched by the on / off circuit 14 in the same manner as in the independent mode.

[0147] FIG. 6 is a corresponding diagram to FIG. 5 in the interlocking mode. For example, the first board 71 can input a trigger signal to all of the plurality of light sources L during the line inspection. The same applies to other control boards.

[0148] <Regarding the reduction of the number of signal distributors> As is well known, in order to synchronize the movement of the stage 5 and the light emission of each light source L, it is conceivable to output a trigger signal from a controller (for example, the first computer 7) for controlling the movement of the stage 5 and input it to the light source L.

[0149] However, generally, it is also conceivable to cause the light source L to emit light at a timing independent of the movement of the stage 5, or to emit light in synchronization with imaging by the review camera 6. In order to realize the latter configuration, for example, as illustrated in FIG. 3, it is conceivable to input a trigger signal from the review camera 6 to the corresponding light source L.

[0150] In addition, in order to be used for the control of the inspection apparatus 1, it is also conceivable to count the trigger signal. In order to count the trigger signal, for example, it is conceivable to distribute the trigger signal output from the controller to each light source L and the corresponding counter among the first counter 91 to the third counter 93.

[0151] Due to these circumstances, it has been a common practice to connect a so-called signal distributor having an OR circuit or the like between signal sources S such as the first computer 7 and the review camera 6 and the light source L.

[0152] On the one hand, in order to increase the inspection speed of the inspection apparatus 1, the inventors of the present application attempted to shorten the emission cycle of the light source L that emits light in synchronization with the imaging by the inspection camera 2. However, in the case of a general light source, there is a limit to the emission frequency, and thus there is a limit to shortening the cycle.

[0153] Therefore, the inventors of the present application provided the first light source 31 and the second light source 32 for one inspection apparatus 1, and configured to cause each light source 31, 32 to emit light in order, thereby arriving at the idea of shortening the cycle for the entire plurality of light sources L.

[0154] However, considering the above circumstances, for the increased number of light sources L, a plurality of signal sources S and signal distributors must also be used respectively. When using a plurality of signal distributors, compared with the case of using one signal distributor, inconveniences can occur from various viewpoints such as securing installation space, cost increase, complication of cable wiring work related to input / output, and thus work mistakes associated with such complication.

[0155] In contrast, according to the above embodiment, as illustrated in FIG. 3, the trigger signal input from the first board 71 as the first signal source via the first input terminal 11a causes the first light source 31 to emit light via the first circuit C1. On the other hand, the trigger signal input from the second board 72 as the second signal source via the second input terminal 11b causes the second light source 32 to emit light via the second circuit C2. Thereby, even though it is one signal distributor 10, a trigger signal can be appropriately transmitted and received between the plurality of signal sources S and the plurality of light sources L.

[0156] Therefore, according to the above embodiment, without increasing the number of signal distributors, different light sources L can be caused to emit light at different timings by trigger signals input from different signal sources S such as the first board 71 and the second board 72. As a result, it is possible to achieve both suppression of the number of signal distributors 10 and shortening of the cycle for the entire plurality of light sources.

[0157] Further, in the above-described embodiment, as illustrated in FIG. 1, the first illumination unit 3 is configured to emit light by the first light source 31 and the second light source 32. The first illumination unit 3 functions as coaxial illumination. Separately from the first illumination unit 3 as coaxial illumination, a case where other illumination that emits light by the third light source 41 is provided is also conceivable.

[0158] Actually, the inspection apparatus 1 according to the present embodiment is configured to include a second illumination unit 4 as oblique illumination. In this case, depending on the use of the inspection apparatus 1, there may be a need to cause the first illumination unit 3 and the second illumination unit 4 to emit light simultaneously or individually.

[0159] In conventional knowledge, in order to meet such needs, it has been essential to provide a signal distributor dedicated to the first illumination unit 3 and a signal distributor dedicated to the second illumination unit 4 side by side.

[0160] On the other hand, according to the above-described embodiment, as illustrated in FIG. 3, without newly providing a signal distributor, it is possible to input a trigger signal to the third light source 41 only by devising the output destinations of the first and second circuits C1 and C2. Thereby, it becomes possible to cause the first illumination unit 3 and the second illumination unit 4 to emit light simultaneously or individually.

[0161] Further, by providing an OR circuit 13 in each of the first circuit C1 and the second circuit C2, it is possible to synchronize the light emission of each of the first illumination unit 3 and the second illumination unit 4. This is advantageous for causing the first illumination unit 3 and the second illumination unit 4 to emit light simultaneously. Furthermore, according to the above-described embodiment, in the first circuit, other input terminals other than the second input terminal are connected, and in the second circuit, other input terminals other than the first input terminal are connected. Thereby, even when there are a large number of input terminals, it becomes possible to cause the first light source and the second light source to emit light at different timings by the trigger signals input from the first and second signal sources.

[0162] Further, according to the above embodiment, as described with respect to the on-off circuit 14 in FIG. 3, the output destinations of the logical sums can be individually turned on and off. As a result, it becomes possible to realize more diverse control, such as causing the first lighting unit 3 and the second lighting unit 4 to emit light simultaneously or individually.

[0163] Further, according to the above embodiment, as described with reference to FIG. 4, the first and second circuits C1 and C2 can be switched to the interlock circuit C3. By switching to the interlock circuit C3, the first light source 31 and the second light source 32 can be caused to emit light simultaneously. As a result, for example, when the amount of light emitted from the first lighting unit 3 is small, it becomes possible to supplement the amount of light.

[0164] <Other Embodiments> In the above embodiment, the inspection device 1 including the first and second computers 7 and 8 has been illustrated, but the configurations of the respective computers 7 and 8 are not limited to the configurations of the above embodiment. At least some of the functions in the first computer 7 may be implemented in the second computer 8, or at least some of the functions in the second computer 8 may be implemented in the first computer 7.

[0165] That is, the above-described first board 71, second board 72, third board 73, and fourth board 81 may be provided in the first computer 7 or may be provided in the second computer 8.

[0166] Further, in the above embodiment, an example in which the first circuit C1 and the second circuit C2 are configured in the signal distributor 10 in the interlock mode has been described, but the present disclosure is not limited to such a configuration. For example, a third circuit, a fourth circuit, etc. may be configured in the signal distributor 10. Also, a third signal source corresponding to the third circuit may be provided, or a fourth signal source corresponding to the fourth circuit may be provided. In addition, a fourth light source may be connected to the third and fourth circuits, or the first and second circuits C1 and C2 in the above embodiment.

[0167] In addition, in the above embodiment, a so-called stage board was used for the first board 71 and the second board 72, but the present disclosure is not limited to such a configuration. The plurality of signal sources S in the present disclosure may be any that output a trigger signal for causing each of the plurality of light sources L to emit light with respect to each of the plurality of light sources L.

Explanation of Signs

[0168] 1 Inspection apparatus 2 Inspection camera (camera) 3 First lighting unit 31 First light source 32 Second light source 4 Second lighting unit 41 Third light source 5 Stage 6 Review camera (signal source) 7 First computer 71 First board (first signal source) 72 Second board (second signal source) 73 Third board (signal source) 8 Second computer 81 Fourth board (signal source) 10 Signal distributor 11 Input terminal 11a First input terminal 11b Second input terminal 12 Output terminal 12a First output terminal 12b Second output terminal 13 OR circuit 13a First OR circuit 13b Second OR circuit 14 On-off circuit W Wafer (object to be inspected) A Target area L Plurality of light sources S Plurality of signal sources C1 First circuit C2 Second circuit C3 Interlocking circuit

Claims

1. A signal distributor connected between a plurality of signal sources each outputting a trigger signal and a plurality of light sources each emitting light based on the trigger signal, and distributing and outputting the trigger signal input from each of the plurality of signal sources to each of the plurality of light sources, including a plurality of input terminals connected to the plurality of signal sources, a first input terminal connected to a first signal source among the plurality of signal sources, and a second input terminal connected to a second signal source that is a signal source other than the first signal source and outputs the trigger signal at a timing different from that of the first signal source, including a plurality of output terminals connected to the plurality of light sources, a first output terminal connected to a first light source among the plurality of light sources, and a second output terminal connected to a second light source other than the first light source, a first circuit that connects the first input terminal to the first output terminal while disconnecting at least the second input terminal from the first output terminal among the plurality of input terminals, and a second circuit that connects the second input terminal to the second output terminal while disconnecting at least the first input terminal from the second output terminal among the plurality of input terminals. A signal distributor characterized by this.

2. In the signal distributor according to claim 1, the first and second circuits are each connected to an output terminal that outputs the trigger signal input via any one of the first and second input terminals to a third light source other than the first and second light sources. A signal distributor characterized by this.

3. In the signal distributor according to claim 2, the first and second circuits each have an OR circuit that outputs a logical sum of the trigger signal input via any one of the first and second input terminals and the trigger signal input via another input terminal other than the first and second input terminals. A signal distributor characterized by this.

4. In the signal distributor according to claim 3, each of the plurality of output terminals individually turns on and off the logical sum output to the plurality of light sources based on a control signal input from the outside. A signal distributor characterized by this.

5. In the signal distributor according to claim 1, The first and second circuits are switched to an interlocking circuit that connects the first input terminal to both the first and second output terminals and connects the second input terminal to both the first and second output terminals based on a control signal input from the outside. A signal distributor characterized by this.

6. A signal distributor according to any one of claims 1 to 5, a camera facing a target area of an object to be inspected, and a stage on which the object to be inspected is placed and that moves relative to the camera, the inspection device being configured to image the target area with the camera while moving the stage and to inspect the object to be inspected based on an image captured by the camera, The first and second signal sources are control boards that alternately output the trigger signal so that the target area is illuminated by at least one of the plurality of light sources in synchronization with imaging by the camera. An inspection device characterized by this.

Images