JP2007194302A - Inspection device for inspection object - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To simplify the structure of an inspection device for an inspection object that uses an optical image or an X-ray image, and to suppress an increase in cost. <P>SOLUTION: The substrate inspection device is provided with a line sensor 34 that picks up an optical image of a substrate 2 as well as the X-ray image of the substrate 2 obtained by irradiating an X ray, and a slave PC to inspect the mounting condition of parts to be inspected by using the obtained optical image and X-ray image. The substrate inspection device moves on the substrate 2, or moves and stops repeatedly thereon, so as to inspect the substrate 2 by using plurally picked-up images. A plurality of line sensors 34 for different pick-up areas are provided in parallel to the image pick-up face of the substrate 2 and vertical to the moving direction of the substrate 2. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an inspection apparatus for an inspection object, and more particularly to an inspection apparatus for an inspection object that inspects an inspection object using an X-ray image of the inspection object obtained by irradiating X-rays.

  In recent years, electronic boards have been mounted on various devices. In devices on which these electronic boards are mounted, downsizing, thinning, and cost reduction have always been challenges, and for this reason, high integration design is widely performed. One of the elements that realize this highly integrated design is high-density mounting technology. The point of this high-density mounting lies in manufacturing technology and inspection technology, and inspection technology using an optical image obtained by imaging the printed circuit board as an inspection of the printed circuit board (hereinafter referred to as “substrate”) after mounting the components. It has been known.

  On the other hand, in order to realize further miniaturization and higher performance of digital equipment, it is required to further increase the degree of integration and reduce the number of components mounted on the substrate. For this reason, for example, BGA (Ball Grid Array), which is one of IC chip packaging methods used for high-density substrate mounting, is often used. In this BGA, pads for external input / output are usually arranged on the lower surface of a flat package. When the BGA is mounted on a substrate, the pad is covered with the package. For this reason, it is difficult for light to reach the pad from the outside, and it is difficult to inspect the connection state of the BGA pad by the inspection method using the optical image as described above. In consideration of components that are difficult to inspect with an optical image as described above, development of an inspection technique using an X-ray transmission image obtained by irradiating a substrate with X-rays is in progress.

As an inspection technique that uses both such an optical image and an X-ray image, for example, in Patent Document 1, an X-ray image of an object to be inspected obtained by an X-ray imaging unit and an optical image obtained by a visible light imaging unit A substrate inspection apparatus for synthesizing the above has been proposed. For example, in Patent Document 2, a step of comparing an optical reference image of a printed circuit board to be inspected with an optical reference image of a printed circuit board to be inspected, and an X-ray image of the printed circuit board to be inspected and a reference print Comparing a substrate with an X-ray reference image of the substrate has been proposed.
JP 2004-340632 A JP 2004-226127 A

  In an inspection apparatus that inspects an object to be inspected such as a substrate using an optical image or an X-ray image, an imaging unit that captures these is generally expensive. In addition, from the viewpoint of facilitating manufacturing and improving maintainability, it is desirable that the configuration of an inspection apparatus that uses both an optical image and an X-ray image is simple.

  The present invention has been made in view of such circumstances, and an object thereof is to simplify the configuration of an inspection apparatus for an object to be inspected that uses an optical image or an X-ray image, and to suppress an increase in cost.

  In order to solve the above-described problems, an inspection apparatus for an inspection object according to an aspect of the present invention captures both an optical image of the inspection object and an X-ray image of the inspection object obtained by irradiating X-rays. And an inspection unit that inspects the mounting state of the components of the object to be inspected using the captured optical image and X-ray image. According to this aspect, it is possible to capture an optical image and an X-ray image without separately providing an imaging unit for capturing an optical image and an imaging unit for capturing an X-ray image. Can be simplified, and an increase in cost can be suppressed.

  An inspection apparatus for an object to be inspected inspects an object to be inspected by using an image captured multiple times while moving the object to be inspected or repeatedly moving and stopping the object to be inspected. A plurality of imaging units having different areas may be arranged substantially perpendicular to the moving direction of the object to be inspected. According to this aspect, an optical image and an X-ray image of different areas of the object to be inspected can be obtained by a plurality of imaging units having different imaging areas, so that the resolution of the optical image and the X-ray image can be increased. Become.

  The imaging unit may capture an X-ray image of the inspection object reflected by the mirror. According to this aspect, the X-ray can be prevented from directly entering the imaging unit, and the imaging unit can be prevented from being exposed to the X-ray. In addition, you may change the optical path of reflected light so that this mirror may inject into the said imaging part fixed.

  The imaging unit may capture the other of the optical image and the X-ray image of the imaging target area of the object to be inspected and then image the other. According to this aspect, the imaging process for imaging an optical image and the imaging process for imaging an X-ray image can be separated. Therefore, for example, control for capturing an optical image and control for capturing an X-ray image, such as control of irradiation timing of visible light and control of irradiation timing of X-rays, can be performed separately. The control for imaging can be facilitated.

  The imaging unit may alternately capture the optical image and the X-ray image of the imaging target region of the object to be inspected a plurality of times. According to this aspect, for example, when an image of the object to be inspected is moved while moving the object to be inspected, the step of capturing an optical image by moving the object to be inspected in one direction and the step of capturing an X-ray image are performed. Can be completed. For this reason, when inspecting a to-be-inspected object using both an optical image and an X-ray image, it can suppress that imaging time becomes long by imaging both an optical image and an X-ray image.

  The inspection apparatus for an object to be inspected according to this aspect has a wavelength that makes the wavelength of light incident on the imaging unit to capture an optical image different from the wavelength of light incident on the imaging unit to capture an X-ray image. A control unit may be further provided. The imaging unit may simultaneously capture an optical image and an X-ray image by simultaneously capturing light having different wavelengths. According to this aspect, an optical image and an X-ray image can be taken simultaneously. For this reason, when inspecting a to-be-inspected object using both an optical image and an X-ray image, it can suppress that imaging time becomes long by imaging both an optical image and an X-ray image.

  The inspection apparatus for an object to be inspected according to this aspect may further include a half mirror that inputs an optical image and an X-ray image to the imaging unit through the same optical path. According to this aspect, it is possible to reduce the necessity of moving the imaging unit in order to image the object to be inspected, and it is possible to suppress an increase in cost for a member for moving the imaging unit.

  ADVANTAGE OF THE INVENTION According to this invention, the structure of the inspection apparatus of the to-be-inspected object using an optical image or an X-ray image can be simplified, and the increase in cost can be suppressed.

  Hereinafter, embodiments of the present invention (hereinafter referred to as “embodiments”) will be described with reference to the drawings.

(First embodiment)
FIG. 1 shows a configuration of a substrate inspection apparatus 200A according to the first embodiment. The substrate inspection apparatus 200A includes an inspection table 10, a substrate transfer table 50, an imaging system 80A, an image processing unit, a slave PC, a master PC, and the like which will be described later. The substrate transport table 50 includes a support plate 52 and two transport rails 54, and the transport rail 54 is supported by the support plate 52.

  The transport rail 54 has a transport belt that transports the substrate 2 by driving a motor, and transports the substrate 2 placed on the transport belt to the approximate center of the inspection table 10. A transport sensor using a non-contact sensor such as an optical sensor (not shown) that detects the transport of the substrate 2 is provided above the transport rail 54 and substantially in the center of the inspection table. When this transport sensor detects the end face of the substrate 2 or a detection hole provided in the substrate 2, the substrate inspection apparatus 200A determines that the substrate 2 has been transported to the approximate center of the inspection table 10, and the substrate 2 is moved by the transport rail 54. Stop conveyance.

  Below the board inspection apparatus 200A, a support shaft (not shown) extending vertically and horizontally with the transport rail 54 is provided. The substrate transport table 50 is provided with an insertion hole through which the support shaft is inserted. A ball screw 56 extending in parallel with the support shaft is provided below the substrate inspection apparatus 200A, and a female screw portion into which the ball screw 56 is fitted is provided on the substrate carrying table 50. The board inspection apparatus 200A is provided with a motor (not shown) that rotationally drives the ball screw 56. When the conveyance of the substrate 2 by the conveyance rail 54 is stopped at the approximate center of the inspection table 10, the substrate inspection apparatus 200 </ b> A rotates the ball screw 56 by operating this motor, and the conveyance rail 54 moves from the stop position of the substrate 2 to the substrate. The substrate 2 is moved in a direction perpendicular to the direction in which the substrate 2 has been conveyed. The substrate inspection apparatus 200A thus transports the substrate 2 transported by the transport rail 54 to the imaging system 80A. Therefore, the substrate transfer table 50 functions as an inspection object transfer unit that transfers the inspection object.

  When the substrate 2 moves to a predetermined position, the substrate inspection apparatus 200A operates the motor to rotate in the reverse direction, rotates the ball screw 56, and moves the substrate transfer table 50 to the position where the substrate 2 is transferred by the transfer rail 54. . The substrate inspection apparatus 200 </ b> A transports the substrate 2 thus moved to the next process by the transport rail 54. If there is a substrate to be inspected next, the substrate 2 to be inspected next is conveyed again to the approximate center of the inspection table 10 by the transport rail 54, and the above operation is repeated.

  The transport rail 54 on the front side of the figure is provided with a clamp that presses the substrate 2 placed on the transport rail 54 from above to correct the shape of the substrate 2. The substrate 2 transported to substantially the center of the inspection table 10 is transported to the imaging system 80A in a state in which the distortion is corrected by the clamp.

  FIG. 2 is a diagram illustrating a configuration of the imaging system 80A according to the first embodiment. The imaging system 80A includes a first imaging system 80a and a second imaging system 80b. The first imaging system 80a includes a first illumination unit 100a, a first imaging unit 30a, a second imaging unit 30b, a microfocus X-ray source 120, and the like. Of the elements constituting the first imaging system 80a, except for the microfocus X-ray source 120, one of the elements to be inspected is transported by the substrate transport table 50 (upper in this embodiment; hereinafter referred to as “upper”). The microfocus X-ray source 120 is disposed around the second illumination unit 100b. The second imaging system 80b includes a second illumination unit 100b, a third imaging unit 30c, a fourth imaging unit 30d, and the like. The elements constituting the second imaging system 80b are arranged on the other side (lower part in the present embodiment, hereinafter referred to as “lower part”) than the board 2 to be inspected carried by the board carrying table 50. (Hereinafter, the first illumination unit 100a and the second illumination unit 100b are collectively referred to as “illumination unit 100” as necessary, and the first imaging unit 30a, the second imaging unit 30b, the third imaging unit 30c, and the fourth imaging unit. The unit 30d is generally referred to as an “imaging unit 30”).

  The first imaging unit 30a includes a first line sensor 34a and a first optical lens 32a. Similarly, the second imaging unit 30b includes a second line sensor 34b and a second optical lens 32b. The third imaging unit 30c includes a third line sensor 34c and a third optical lens 32c. The fourth imaging unit 30d includes a fourth line sensor 34d and a fourth optical lens 32d (hereinafter, the first line sensor 34a and the fourth line sensor 34d are collectively referred to as a “line sensor 34” as necessary. The first optical lens 32a and the fourth optical lens 32d are collectively referred to as “optical lens 32”). Each of the line sensors 34 images light incident through the telecentric lens 42 and converts it into image data.

  The illumination unit 100 irradiates the imaged surface of the transported substrate 2 with light. The light reflected by the substrate 2 is reflected by a later-described half mirror disposed in the illumination unit 100 and is incident on the imaging unit 30. The light incident on the imaging unit 30 passes through the optical lens 32 and enters the line sensor 34. The line sensor 34 scans the incident light in this way, picks up an optical image as an image by visible light, and converts it into image data. Therefore, the line sensor 34 functions as an optical image capturing unit that captures an optical image.

  Here, “scanning” indicates an operation in which the scanning head is driven in a direction perpendicular to the arrangement direction of the image sensors of the line sensor 34. “Imaging” indicates that the line sensor 34 scans one scanning unit. One scanning unit refers to a unit of scanning of the line sensor 34, for example, one-time scanning from one end of the substrate to the other end and one reciprocating scanning. Hereinafter, in the present specification, the transport direction of the substrate 2 is referred to as “transport direction”, and the scanning direction of the line sensor 34 perpendicular to the transport direction of the substrate 2 is referred to as “scan direction”.

  The first imaging unit 30a and the second imaging unit 30b are fixed on the upper frame 36a. The upper frame 36a is supported by the upper support frame 38 so as to be slidable in the transport direction. A motor 40 is fixed to the upper support frame 38, and a male screw portion is provided on the motor shaft of the motor 40. The upper frame 36 a is provided with a female screw portion that fits with the male screw portion of the motor 40. When the motor 40 is driven, the upper frame 36 a moves with respect to the upper support frame 38. The substrate inspection apparatus 200A gives a control signal to the motor 40 to drive it based on substrate thickness data inputted in advance. As a result, the upper frame 36a is slid with respect to the first illumination unit 100a, and the focal point is set for imaging the upper surface of the substrate 2. The third imaging unit 30c and the fourth imaging unit 30d constituting the second imaging system 80b are fixed on the lower frame 36b.

  The first imaging unit 30a, the second imaging unit 30b, and the two telecentric lenses 42 are juxtaposed in the scanning direction so as to have different imaging areas so as to share and image one surface of the substrate 2 that is an object to be inspected. In addition, the first optical lens 32a, the first line sensor 34a, the second optical lens 32b, the second line sensor 34b, so that the imaging ranges of the first line sensor 34a and the second line sensor 34b have overlapping imaging ranges. The arrangement of the telecentric lens 42 is determined.

  Similarly, in the second imaging system 80b, the third imaging unit 30c, the fourth imaging unit 30d, and the two telecentric lenses 42 have different imaging areas so as to share the other surface of the substrate 2 for imaging. They are arranged side by side in the scanning direction. In addition, the third optical lens 32c, the third line sensor 34c, the fourth optical lens 32d, the fourth line sensor 34d, and the third line sensor 34c and the fourth line sensor 34d have an overlapping imaging range. The arrangement of each telecentric lens 42 is determined. Since the plurality of line sensors 34 are arranged in parallel in the scanning direction in this way, an optical image and an X-ray image of different regions of the substrate 2 can be obtained by the plurality of line sensors 34, and an optical image and an X-ray image to be captured are captured. It is possible to increase the resolution. In this embodiment, two line sensors 34 are provided above the substrate 2 to be transported, and two line sensors 34 are provided below the substrate 2. However, the line sensors 34 provided above and below the substrate 2 are three. Of course, there may be more than one.

  The first line sensor 34a, the second line sensor 34b, and the first illumination unit 100a, and the third line sensor 34c, the fourth line sensor 34d, and the second illumination unit 100b are formed on the substrate 2 in one inspection process. It arrange | positions so that it may oppose on both sides of the board | substrate 2 so that both surfaces can be imaged.

  FIG. 3 is a diagram illustrating a configuration of the illumination unit 100 according to the first embodiment. The lighting unit 100 includes a first lighting unit 100a and a second lighting unit 100b. The first lighting unit 100a and the second lighting unit 100b include a first light source 102, a second light source 104, a third light source 106, an acrylic sheet 112, and the like.

  The first light source 102 is composed of a group of LEDs (light emitting diodes) arranged in the scanning direction of the line sensor 34 so as to be longer than the length of the substrate 2 that is an inspection object. The first light source 102 is arranged directly above the scanning line on the substrate 2 scanned by the line sensor 34 so that the light incident on the substrate 2 can be irradiated. In the present embodiment, the first light source 102 is arranged. Is composed of a group of LEDs provided on a substrate disposed in parallel with the surface to be imaged of the substrate 2. In order to efficiently project incident light onto the scanning line being inspected, the board to which the LED group is attached is divided into two sub-boards from the center, and the LED group is arranged on each sub-board in the scanning direction. Also good. By projecting incident light onto the substrate 2 by the first light source 102 and detecting this reflected light with the line sensor 34, it is possible to determine the position displacement of the components in the substrate 2, lack of parts, solder slippage, and the like.

  The second light source 104 is a group of LEDs arranged on two substrates arranged in parallel with the imaging surface of the substrate 2 and arranged in the scanning direction of the line sensor 34 so as to be longer than the length of the substrate 2 that is an object to be inspected. Consists of. The two substrates to which the LEDs are attached are arranged on both sides of the scanning line in the substrate transport direction so that the first light source does not interfere with the optical path that projects incident light on the scanning line.

  Similarly to the second light source 104, the third light source 106 is provided on two substrates arranged in parallel with the imaging surface of the substrate 2, and the third light source 106 is connected to the substrate 2 that is an object to be inspected in the scanning direction of the line sensor 34. It is composed of a group of LEDs that are longer than the length. The two substrates to which the LEDs are attached are arranged on both sides of the scanning line in the substrate transport direction so that the first light source and the second light source do not interfere with the optical path that irradiates the scanning line with light. By projecting side light onto the substrate 2 by the second light source 104 and detecting this reflected light with the line sensor 34, it is possible to determine the presence or absence of a solder bridge in the substrate 2, a wrong mounting component, polarity inversion, and the like. .

  In these light sources, the first light source 102 emits green light, the second light source 104 emits white light, and the third light source 106 emits blue light. Each light source irradiates the board | substrate 2 which is a to-be-inspected object at a different incident angle. For this reason, the illumination unit 100 functions as a composite light source that irradiates light having a plurality of incident angles onto the substrate 2 that is an object to be inspected. The reason why the first light source 102 is set to green and the third light source 106 is set to blue is that with the recent progress in LED technology, green LEDs and blue LEDs are brighter than white LEDs and a clear image with a good SN ratio can be obtained. Because. Since the printed circuit board is often green, the first light source is green in order to brightly illuminate the plain with incident light. In addition, since the characters laser-printed on the body of the IC or chip are easily recognized by applying blue light from a low angle, the third light source 106 is blue.

  A half mirror 110 is provided vertically below the first light source 102. Incident light from the first light source 102 passes through the half mirror 110 and is incident on the inspection surface of the substrate 2 with an incident angle of substantially zero. In the present embodiment, the first light source 102 has a width, and it is considered that there is an incident light component such that the incident angle becomes zero even when the substrate 2 is warped. The reflected light from the scanning line is reflected by the half mirror 110, passes through the telecentric lens 42, and enters the line sensor 34.

  An acrylic sheet 112 is provided between the second light source 104 and the third light source 106 and the scanning line. The acrylic sheet 112 diffuses light from the second light source 104 and the third light source 106. Since the second light source 104 and the third light source 106 are a collection of LEDs that are point light sources, if there is no diffusing action, spot-like light may be reflected in the image data and affect the inspection accuracy. is there.

  In the present embodiment, each light source is lit independently in the order of white light from the second light source 104, green light from the first light source 102, and blue light from the third light source 106. Each light source is turned on three times per scanning unit. The line sensor 34 scans the substrate 2 every time it is turned on.

  The substrate 2 may leak light from the end of the substrate 2 to the opposing illumination unit 100. In addition, since the substrate 2 may have a hole or a hole that has not been filled with solder, the light may leak from the hole to the opposing lighting unit 100. When the light leaking from the facing illumination unit 100 is directly scanned by the line sensor 34 in this way, a phenomenon called blooming occurs, which may affect the imaging of the substrate 2. For this reason, in this embodiment, the 1st lighting unit 100a and the 2nd lighting unit 100b are offset and arrange | positioned in the conveyance direction of a board | substrate.

  The microfocus X-ray source 120 is vertically below the first illumination unit 100a and the substrate 2 to be transported, and the second illumination unit 100b is disposed offset so that the substrate 2 emits X-rays from below vertically. It arrange | positions in the position which can be irradiated. More specifically, the microfocus X-ray source 120 is disposed between the second light source 104 and the third light source 106 of the first illumination unit 100a at a position where X-rays can be irradiated from vertically below.

  A scintillator 116 is provided above the second light source 104 and on the locus of X-rays that have passed between the second light source 104 and the third light source 106. The image displayed on the scintillator 116 is reflected by the mirror 114, passes through the half mirror 110, the telecentric lens 42, and the like and enters the line sensor 34.

  FIG. 4 is a diagram illustrating light paths indicating X-rays and X-ray images in the first embodiment. The microfocus X-ray source 120 irradiates the transported substrate 2 with X-rays. Therefore, the microfocus X-ray source 120 functions as an X-ray irradiation apparatus that irradiates the substrate 2 with X-rays. The X-rays irradiated on the substrate 2 pass through the substrate 2. At this time, a portion containing metal such as solder absorbs X-rays, so that X-rays passing through the substrate 2 are attenuated. The scintillator 116 is irradiated with the X-ray image partially attenuated in this way. The scintillator 116 is formed of an aluminum material, and a fluorescent paint that displays an X-ray image in response to X-rays is applied to the surface. When the scintillator 116 is irradiated with X-rays, the scintillator 116 displays an X-ray image on the surface with visible light according to the X-ray attenuation. Therefore, the scintillator 116 functions as an optical conversion unit that converts X-rays that have passed through the object to be inspected into an X-ray image by visible light.

  The X-ray image displayed on the scintillator 116 is reflected by the mirror 114 disposed in the vicinity of the first illumination unit 100 a, passes through the telecentric lens 42 and the optical lens 32, and enters the line sensor 34. The line sensor 34 scans the incident light in this way and captures an X-ray image displayed on the scintillator 116. Therefore, the first line sensor 34 a and the second line sensor 34 b function not only as a visible light imaging unit but also as an X-ray image imaging unit that captures an X-ray image as an X-ray transmission image of the substrate 2.

  As described above, the optical image and the X-ray image of the substrate 2 are captured by the same imaging unit. As a result, an optical image and an X-ray image can be captured without separately providing an imaging unit for capturing an optical image and an imaging unit for capturing an X-ray image. Can be simplified, and an increase in cost can be suppressed. Further, since the first line sensor 34a and the second line sensor 34b capture an X-ray image of the substrate 2 reflected by the mirror 114, the X-rays are directly incident on the first line sensor 34a and the second line sensor 34b. Exposure to the wire is suppressed.

  FIG. 5 is a conceptual configuration diagram of a substrate inspection apparatus 200A according to the first embodiment. In the present embodiment, the board inspection apparatus 200A includes one master PC 160, four slave PCs 140 including a first slave PC 140a and a fourth slave PC 140d (hereinafter collectively referred to as “slave PC 140” as necessary), and four images. A processing unit 130 is included. The master PC 160 and each slave PC 140 are connected by a switching hub 150.

  The master PC 160 includes an illumination control unit 161, a scan control unit 162, a transport control unit 163, an X-ray control unit 164, a display control unit 165, a transmission / reception unit 166, and a display 167. The illumination control unit 161 is connected to the first illumination unit 100a and the second illumination unit 100b. The illumination control unit 161 controls the illumination unit 100 so as to irradiate light along with scanning by the line sensor 34 in one scanning unit.

  The illumination control unit 161 controls the first illumination unit 100a and the second illumination unit 100b so as to simultaneously irradiate the substrate 2 with light of the same color when performing the light irradiation on the substrate 2 synchronously. In the present embodiment, the illumination control unit 161 is configured to simultaneously apply light of the same color and the same incident angle in the order of white light from the second light source 104, green light from the first light source 102, and blue light from the third light source 106. The first illumination unit 100a and the second illumination unit 100b are controlled so as to irradiate 2. Thereby, for example, even when the irradiation light from the first illumination unit 100a is irradiated onto the irradiation surface of the substrate 2 on which the second illumination unit 100b irradiates light due to reflection by peripheral components, the light interference The influence on the appearance inspection of the substrate 2 due to is suppressed to a minimum.

  The scanning control unit 162 is configured to scan the substrate 2 in synchronization with one scanning unit at a timing when any one of the first light source 102, the second light source 104, and the third light source 106 irradiates the substrate 2 with light. Each of the sensors 34 is controlled. In addition, the X-ray control unit 164 controls the microfocus X-ray source 120 so that X-rays are emitted in accordance with scanning by the line sensor 34 in one scanning unit. The scanning control unit 162 sets the first line sensor 34a and the second line sensor 34b so that the substrate 2 is scanned in synchronization with one scanning unit at the timing when the microfocus X-ray source 120 irradiates the substrate 2 with X-rays. Control.

  The conveyance control unit 163 is connected to the motor 58. The motor 58 transports the substrate 2 by moving the substrate transport table 50. Therefore, the motor 58 and the substrate transfer table 50 have a function as a substrate transfer means. When the substrate 2 is scanned in one scanning unit, the transport control unit 163 controls the motor 58 so as to transport the substrate 2 by one scanning unit.

  The first line sensor 34a and the fourth line sensor 34d are connected to the first slave PC 140a and the fourth slave PC 140d via the image processing unit 130, respectively. Each of the slave PCs 140 includes a memory 141, an analysis unit 142, a determination criterion storage unit 143, and a transmission / reception unit 144. The image processing unit 130 performs image processing on the received optical image data and X-ray image data, and transmits the processed image data to the corresponding slave PC 140. The slave PC 140 stores the received optical image data and X-ray image data in the memory 141.

  The analysis unit 142 analyzes shared data necessary for the inspection of the substrate 2 in the other slave PC 140 among the optical image data and the X-ray image data stored in the memory 141. The shared data is, for example, the position data of a recognition mark indicating the position of the substrate 2 provided on the substrate 2, the substrate 2 serial number obtained by analyzing the identification mark such as a barcode provided on the substrate 2, and the manufacturing Identification data such as date, date of parts imaged across different line sensors 34, and other data necessary for inspection of the board 2.

  When the analysis unit 142 analyzes the image and acquires the shared data necessary for the inspection of the board 2, the slave PC 140 stores the shared data in the memory 141 and transmits the shared data to the other slave PCs 140. The analysis unit 142 analyzes the optical image data and the X-ray image data stored in the memory 141 using the received shared data. In addition, the analysis unit 142 refers to the determination criteria stored in the determination criterion storage unit 143 and inspects the substrate 2. Therefore, the slave PC 140 functions as an inspection unit that inspects the mounting state of the components of the board 2 using the captured optical image and X-ray image. The component mounting state is not only the presence / absence or position of a component such as an element mounted on the substrate 2 as an object to be inspected but also whether it is a proper component, etc. Including.

  Each of the slave PCs 140 transmits the shared data and the inspection result of the board 2 to the master PC 160. The display control unit 165 of the master PC 160 displays the error location of the board 2 on the display 167 using the received shared data and the inspection result of the board 2.

  In the step of transporting the substrate 2 in one direction, the substrate inspection apparatus 200A first completes the imaging by the line sensor 34 of the optical image of the entire imaging surface of the substrate 2 as the target imaging region. When the imaging of the optical image of the substrate 2 is completed, the motor 58 is rotated in the reverse direction to transport the substrate 2 in the reverse direction. The substrate inspection apparatus 200 </ b> A captures an X-ray image of the substrate 2 by the line sensor 34 in the process of transporting the substrate 2 in the reverse direction. As described above, the substrate inspection apparatus 200A separates the imaging process for capturing an optical image and the imaging process for capturing an X-ray image. Thus, for example, control for capturing an optical image and control for capturing an X-ray image, such as control of irradiation timing by the illumination unit 100 and control of X-ray irradiation timing by the microfocus X-ray source 120, are also separated. The control for capturing each image can be facilitated. In the step of transporting the substrate 2 in one direction, the substrate inspection apparatus 200A first completes the imaging of the X-ray image of the entire surface to be imaged of the substrate 2 as the target imaging region, and the substrate 2 is reversed. Of course, an optical image of the substrate 2 may be taken in the transporting step. In addition, the target imaging area may not be the entire area of the imaging surface of the substrate 2, and may be, for example, only an area where a predetermined component mounted on the substrate 2 exists.

  The substrate inspection apparatus 200 </ b> A may alternately capture an optical image and an X-ray image of one substrate 2 by a line sensor 34 a plurality of times. Specifically, when the line sensor 34 captures an optical image in one scanning unit, the board inspection apparatus 200A captures an X-ray image in one scanning unit using the first line sensor 34a and the second line sensor 34b. The substrate inspection apparatus 200A transports the substrate 2 by one scanning unit when the imaging of the optical image and the X-ray image of one scanning unit is completed. Thereafter, by repeating this operation, the substrate inspection apparatus 200A captures an optical image and an X-ray image of the entire substrate 2 by the line sensor 34. Thereby, the imaging of the optical image and the X-ray image can be completed in the step of moving the substrate 2 in one direction. For this reason, in the board | substrate inspection apparatus 200A of this embodiment which test | inspects the board | substrate 2 using both an optical image and an X-ray image, imaging time becomes long by imaging both an optical image and an X-ray image. Can be suppressed.

(Second Embodiment)
FIG. 6 is a diagram illustrating a configuration of an imaging system 80B according to the second embodiment. The imaging system 80B includes a first imaging system 80c and a second imaging system 80d. The first imaging system 80c includes a first illumination unit 100a, a microfocus X-ray source 120, an upper frame 36a, and a plurality (five in this embodiment) of CCD sensors 172 and a plurality of (this embodiment). It has five lenses 174 in the form. The second imaging system 80d includes a plurality of (five in the present embodiment) CCD sensors 172 and a plurality (five in the present embodiment) provided on the second illumination unit 100b, the lower frame 36b, and the lower frame 36b. ) Lens 174. Since the first illumination unit 100a, the second illumination unit 100b, and the microfocus X-ray source 120 are the same as those in the first embodiment, the description thereof is omitted. The CCD sensor 172 captures a two-dimensional region at a time and converts it into image data.

  The plurality of CCD sensors 172 are arranged on the upper frame 36a and the lower frame 36b in parallel with the surface to be imaged of the substrate 2 and perpendicular to the conveyance direction of the substrate 2. A lens 174 is provided for each CCD sensor 172. The CCD sensor 172 images a two-dimensional area of the substrate 2. The lens 174 adjusts the size of the two-dimensional area imaged by the CCD sensor 172. In the present embodiment, the CCD sensor 172 is disposed so that the respective imaging areas overlap in a direction perpendicular to the conveyance direction of the substrate 2. In this way, a plurality of CCD sensors 172 arranged in parallel can simultaneously image a two-dimensional region of the entire length in the direction perpendicular to the transport direction of the substrate 2 and a predetermined length in the transport direction. It has become. Hereinafter, in this specification, an imaging region of a plurality of CCD sensors 172 arranged in parallel will be described as one imaging unit.

  In the present embodiment, a lens 174 and a CCD sensor 172 are provided in place of the optical lens 32 and the line sensor 34 in FIG. Accordingly, both the upper and lower CCD sensors 172 of the transported substrate 2 function as an optical image capturing unit that captures an optical image of the substrate 2. The CCD sensor 172 on the upper side of the substrate 2 to be transported also functions as an X-ray image capturing unit that captures an X-ray image as an X-ray transmission image of the substrate 2.

  FIG. 7 is a conceptual configuration diagram of a substrate inspection apparatus 200B according to the second embodiment. The configuration of the substrate transfer table 50 and the like is the same as that of the first embodiment. The board inspection apparatus 200B includes an imaging system 80, a first slave PC 140e, a second slave PC 140f, an image processing unit 130, a master PC 160, and the like. The first slave PC 140e, the second slave PC 140f, and the master PC 160 are connected to each other by a switching hub 150. Note that the description of the same parts as in the first embodiment is omitted.

  The imaging control unit 169 is connected to each of the CCD sensors 172. The imaging control unit 169 controls each of the CCD sensors 172 so that one of the first light source 102, the second light source 104, and the third light source 106 images the substrate 2 in one imaging unit at the timing when the substrate 2 is irradiated with light. To control. In addition, the imaging control unit 169 of the first imaging system 80c causes the CCD of the first imaging system 80c to image the substrate 2 in one imaging unit at the timing when the microfocus X-ray source 120 irradiates the substrate 2 with X-rays. The sensor 172 is controlled. When the substrate 2 is imaged in one imaging unit, the conveyance control unit 163 controls the motor 58 to convey the substrate 2 by one imaging unit.

  Also in the present embodiment, in the process of transporting the substrate 2 in one direction, the substrate inspection apparatus 200B first completes the imaging of the optical image of the substrate 2 by the CCD sensor 172, and the process of transporting the substrate 2 in the reverse direction. 2, an X-ray image of the substrate 2 is picked up by the CCD sensor 172. The substrate inspection apparatus 200B first completes the imaging of the X-ray image of the substrate 2 by the CCD sensor 172 in the process of transporting the substrate 2 in one direction, and the CCD in the process of transporting the substrate 2 in the reverse direction. Of course, an optical image of the substrate 2 may be taken by the sensor 172. Of course, the substrate inspection apparatus 200 </ b> B may alternately take an optical image and an X-ray image of one substrate 2 by a CCD sensor 172 a plurality of times.

  A plurality of CCD sensors 172 may not be provided in parallel, and a single CCD sensor 172 may move in a direction perpendicular to the transport direction to sequentially capture an optical image or an X-ray image. As a result, the cost can be reduced compared to the case where a plurality of CCD sensors 172 are arranged in parallel.

  The present invention is not limited to the above-described embodiments, and an appropriate combination of the elements of each embodiment is also effective as an embodiment of the present invention. Various modifications such as design changes can be added to each embodiment based on the knowledge of those skilled in the art, and embodiments to which such modifications are added can also be included in the scope of the present invention. Here are some examples.

  The substrate inspection apparatus determines the wavelength of light incident on the line sensor 34 or the CCD sensor 172 for capturing an optical image and the wavelength of light incident on the line sensor 34 or the CCD sensor 172 for capturing an X-ray image. You may further provide the wavelength control part made to differ. The line sensor 34 or the CCD sensor 172 may simultaneously capture an optical image and an X-ray image by simultaneously capturing light having different wavelengths.

  For example, a scintillator irradiation unit that irradiates the surface of the scintillator 116 with light having a predetermined wavelength is provided. The illumination control unit 161 irradiates the substrate 2 with X-rays by the microfocus X-ray source 120 at the timing when the illumination unit 100 irradiates the substrate 2 with blue light, and further irradiates the scintillator 116 with a color having a wavelength different from blue. The lighting unit 100 and the scintillator irradiation unit are controlled to do so. The line sensor 34 or the CCD sensor 172 provided on the upper part of the substrate to be transported simultaneously images light having different wavelengths. The image processing unit 130 or the slave PC 140 performs image processing on the image data obtained by imaging and separates the image data obtained by separating the image data for each wavelength into an optical image and an X-ray image. In this case, the illumination control unit 161, the illumination unit 100, and the scintillator irradiation unit constitute a wavelength control unit. Accordingly, when inspecting the object to be inspected using both the optical image and the X-ray image, it is possible to suppress an increase in imaging time by capturing both the optical image and the X-ray image.

  In the first embodiment, the scanning control unit 162 may change the scanning speed scanned by the line sensor 34. Further, the scanning control unit 162 may change the sampling frequency when the line sensor 34 scans to capture an optical image or an X-ray image. Accordingly, it is possible to realize optical zoom in the scanning direction when capturing an optical image and X-ray zoom in the scanning direction when capturing an X-ray image.

  A housing for housing the first light source 102, the second light source 104, or the third light source 106 may be formed of an aluminum material. By applying a fluorescent material that displays an X-ray image in response to X-rays on this surface, the housing that accommodates each light source may function as a scintillator. As a result, the configuration of the substrate inspection apparatus can be simplified, and the number of assembling steps during manufacturing can be reduced.

  You may arrange | position the shading plate shape | molded by lead in the plate shape around the board | substrate 2 to convey. The thickness of the shading plate is preferably accurate. The board inspection apparatus may perform shading correction for capturing an optical image or an X-ray image using the shading plate. In this case, the board inspection apparatus turns on the first light source 102, the second light source 104, and the third light source 106 independently, and calibrates the shading correction value using the captured optical image. Further, the substrate inspection apparatus uses an X-ray image obtained by irradiating the shading plate with X-rays by the microfocus X-ray source 120 and capturing an X-ray image displayed on the scintillator 116 by the X-rays that have passed through the shading plate. Calibrate the shading correction value. Thus, by using the shading plate for calibration of shading correction, it becomes possible to calibrate shading correction for both the optical image and the X-ray image.

  In addition, a plurality of reference holes may be provided in the shading plate. In this case, the substrate inspection apparatus irradiates the shading plate with light by the illumination unit 100 and images the reflected light before inspecting the transported substrate 2. The board inspection apparatus uses the captured image of the shading plate to set the origin of the optical image and X-ray image of the board 2, measure the image magnification, and generate a correction map for image distortion. By using a shading plate formed of lead in this way, the origin and pixel size of both the optical image and the X-ray image of the substrate 2 can be corrected.

  This shading plate may have a plurality of plate thicknesses. In this case, the microfocus X-ray source 120 irradiates the shading plate with X-rays. An X-ray image having shading is displayed on the scintillator 116 by X-rays that have passed through a shading plate having a plurality of plate thicknesses. The board inspection apparatus performs gamma correction calibration using the X-ray image obtained by capturing the scintillator 116 on which the X-ray image is displayed in this manner. This makes it possible to perform gamma correction calibration of the X-ray image.

It is a figure which shows the structure of the board | substrate inspection apparatus which concerns on 1st Embodiment. 1 is a diagram illustrating a configuration of an imaging system according to a first embodiment. It is a figure which shows the structure of the illumination unit which concerns on 1st Embodiment. In 1st Embodiment, it is a figure which shows the path | route of the light which shows an X-ray and an X-ray image. It is a conceptual lineblock diagram of the substrate inspection device concerning a 1st embodiment. It is a figure which shows the structure of the imaging system which concerns on 2nd Embodiment. It is a conceptual lineblock diagram of a substrate inspection device concerning a 2nd embodiment.

Explanation of symbols

  2 substrate, 30 imaging unit, 34 line sensor, 42 telecentric lens, 100 illumination unit, 110 half mirror, 114 mirror, 116 scintillator, 120 microfocus X-ray source, 172 CCD sensor, 200A and 200B substrate inspection apparatus.

Claims (7)

An imaging unit that captures both an optical image of the object to be inspected and an X-ray image displayed on the optical conversion unit by irradiating the object to be inspected with X-rays;
An inspection unit that inspects the mounting state of the components of the object to be inspected using the captured optical image and X-ray image;
A device for inspecting an object to be inspected. An inspected object transport unit for transporting the inspected object;
An imaging control unit that images the object to be inspected while conveying the object to be inspected, or repeatedly conveying and stopping the object to be inspected,
The inspection apparatus for an object to be inspected according to claim 1, wherein a plurality of the image pickup units having different image pickup areas are arranged side by side substantially perpendicular to the moving direction of the object to be inspected.   3. The inspection object inspection apparatus according to claim 1, wherein the imaging unit captures an X-ray image of the inspection object reflected by a mirror.   The inspected device according to claim 1, wherein the imaging unit captures one of an optical image and an X-ray image of an imaging target region of the object to be inspected, and then images the other. Body inspection device.   The inspecting device according to any one of claims 1 to 3, wherein the imaging unit alternately captures an optical image and an X-ray image of an imaging target region of the inspected object a plurality of times. . A wavelength control unit that varies the wavelength of light incident on the imaging unit to capture an optical image and the wavelength of light incident on the imaging unit to capture an X-ray image;
The inspected object according to any one of claims 1 to 3, wherein the imaging unit captures an optical image and an X-ray image simultaneously by simultaneously capturing light having different wavelengths. Inspection equipment.   The inspection apparatus for an object to be inspected according to claim 1, further comprising a half mirror that inputs an optical image and an X-ray image to the imaging unit through the same optical path.

Images