TW201300768A - Method for setting up inspection area and X-ray inspection system - Google Patents

Abstract

This invention is to provide an X-ray inspecting method capable of precisely setting up an inspected area of an object to be inspected, by utilizing an X-ray image for inspecting the object to be inspected. In an X-ray inspecting device for inspecting a object to be inspected, a method for setting up an inspection area of the object to be inspected is comprised of: step (S104), photographing a visible image in a first area including the object to be inspected; step (S112), photographing an X-ray image in a second area including the object to be inspected; step (S118), displaying all of the visible image in the first area and the X-ray image in the second area together with a mark for showing the position of the object to be inspected at the same time based on the condition that position and the magnification of the visible image and the X-ray image are in unison; step (S120), receiving an input of an confirmation related to the position of the mark of the displayed object to be inspected and the position of the X-ray image, in order to confirm the inspection area.

Description

Inspection area setting method and X-ray inspection system

The present invention relates to an inspection region setting method and an X-ray inspection system, and more particularly to an inspection region setting method and an X-ray inspection system for inspecting the bonding between a printed substrate and a circuit component.

X-ray CT (Computed Tomography) has been used for the purpose of checking the welding state by a non-destructive inspection method for parts soldered on a printed circuit board (hereinafter also referred to as "substrate"). In the X-ray CT, an object is imaged by X-rays in a plurality of directions, and a plurality of fluoroscopic images showing a distribution of the degree of absorption (attenuation amount) of X-rays are obtained. Then, the reconstruction processing is performed based on the plurality of fluoroscopic images, and two-dimensional data or three-dimensional data of the distribution of the X-ray absorption coefficient of the inspection object is obtained.

In such an inspection, there are cases in which a plurality of substrates having the same shape are successively inspected at the same position. In this case, the inspection object is used as a reference for positioning, and the inspection position is taught to the inspection device (teaching, Instructions). Next, an X-ray image of the same type of measured object is successively generated for the inspected inspection position, and each of the measured objects is inspected based on the fluoroscopic image.

The techniques for such inspections have revealed many species since the past. For example, in the technique disclosed in Patent Document 1 or Patent Document 2, when an input of an inspection position is accepted in the teaching, a visible light image of the object to be measured is displayed.

Regarding the substrate, in order to check whether the welding condition of the above-mentioned parts is good or not, not only the position of the part but also the welding position for specifying the part Set the information such as the position or shape of the inspection object.

However, in the conventional inspection apparatus, when a part such as a BGA (Ball Grid Array) in which the welded portion is covered by the part body and is invisible is attached to the substrate, the accuracy of the information input such as the welding position is greatly affected by the user experience. Therefore, there is a problem that the accuracy of the inspection is greatly affected by the user experience. Further, even in the case of a packaging component such as a QFP (Quad Flat Package), the user must specify a plurality of welding positions for each component one by one, and thus there is a problem that the user has to perform complicated work.

Therefore, in the case where the above-described X-ray CT is used as the in-line inspection device, in order to improve the above problem, it is known to inspect the inspection region and the inspection logic for the inspection sites of the plurality of substrates present. For example, Patent Document 3 (JP-A-2010-160071) discloses that when the user is taught the appearance and position of the component, the CT is reconfigured and the ball (electrode position) electrode position is extracted.

Further, Patent Document 4 (JP-A-2006-220640) discloses a technique of photographing a CCD camera to be photographed in a coaxial direction with a holding mechanism of a subject and an X-ray source, without requiring an X-ray source. The alignment is performed without misalignment and can be detected correctly, wherein the retention mechanism is rotatable relative to the X-ray source and detector.

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2007-218784

[Patent Document 2] Japanese Patent Laid-Open Publication No. 2007-127490

[Patent Document 3] Japanese Patent Laid-Open Publication No. 2010-160071

[Patent Document 4] Japanese Laid-Open Patent Publication No. 2006-220640

However, for example, Japanese Laid-Open Patent Publication No. 2010-160071 discloses that in a configuration in which a position of an inspection region is displayed in a rectangular shape or the like in a visible light image, sufficient information is not necessarily displayed to the user to determine whether the inspection position is correct, and the accuracy of the inspection is still Depends on the user's experience.

Further, in the substrate inspection, the back surface may be inspected in addition to the surface of the substrate. In this case, after the surface and the back surface are correctly aligned and overlapped, if the user does not confirm the inspection target and its position, the wrong area may be obtained. Set to the inspection area.

Further, in the technique disclosed in Japanese Laid-Open Patent Publication No. 2006-220640, the through image and the CCD image are taken coaxially, and the surface image and the internal image are combined and displayed. The premise of doing this is for parsing, not for checking the location of the auto-check. Further, for example, in the case of a printed substrate, when the object is larger than the field of view of the camera and the field of view of the X-ray inspection machine, the inspection area cannot be set.

The present invention has been made in view of the above-described circumstances, and an object of the present invention is to provide an inspection area setting method and an X-ray inspection system for setting an inspection of an object to be inspected with good precision when an object to be inspected is inspected using an X-ray image. region.

Another object of the present invention is to provide an inspection area setting method, an X-ray inspection apparatus, and an X-ray inspection program. When a substrate of an electronic component is mounted on an object to be inspected, connection wiring for the mounting part and the substrate can be accurately and easily input. News.

According to one aspect of the present invention, in an X-ray inspection apparatus that performs inspection of an inspection object using X-rays, an inspection area setting method for setting an inspection area of the object to be inspected is provided. The following steps: a step of capturing a visible light image of the first region including the object to be inspected; a step of performing X-ray image capturing on the second region including the object to be inspected; and the first region The visible light image and the X-ray image of the second region are displayed simultaneously with the mark indicating the position of the inspection target when the position and the magnification are the same; and the inspection of the mark position and the X-ray image of the inspection object to be displayed The position of the object, the step of accepting the input of the confirmation to determine the inspection area.

Preferably, the object to be inspected is a substrate in which a plurality of electronic components are disposed, and the visible light image capturing means includes a step of capturing a first visible light image on the surface side of the substrate and a second visible light image on the back side; and simultaneously displaying the steps The step of displaying the first or second visible light image when the X-ray image is aligned with the position and the magnification; and the determining step includes the step of determining the respective inspection areas on the front side and the back side.

Preferably, the X-ray image includes a reconstructed image of a region to be inspected by the object to be inspected by a plurality of X-ray images captured from a plurality of perspective directions.

Preferably, the reconstructed image includes a tomographic image of a cross section parallel to the substrate which is a portion of the inspection target which is a blind spot in the first and second visible light images.

Preferably, the X-ray image is an X-ray image of the object to be inspected.

According to another aspect of the present invention, an X-ray inspection system using an X-ray inspection object includes: a memory means for storing information of a position of an inspection object of a designated inspection object; and a visible light image capturing means for photographing including The visible light image of the first region of the object to be inspected; the X-ray image capturing means captures the X-ray image of the second region including the object to be inspected; and the output means, the visible light image of the first region and the second image The X-ray image of the area is displayed when the position and the magnification are the same, and the mark indicating the position of the inspection object is simultaneously displayed according to the information stored in the memory means; the input means is for the marked position of the displayed inspection object and the X-ray The position of the inspection object in the image, the input for accepting the confirmation; and the control means, according to the input, the setting information for the specific determined inspection area is stored in the memory means.

Preferably, the object to be inspected is a substrate on which a plurality of electronic components are arranged; the visible light image capturing means is to capture the first visible light image on the surface side of the substrate and the second visible light image on the back side; and the output means is the first or second Any one of the visible light images is displayed when the X-ray image is in the same position and magnification; and the control means stores the setting information for the inspection areas of the specific surface side and the back side in the memory means.

Preferably, the X-ray image includes a reconstructed image of a region to be inspected by the object to be inspected by a plurality of X-ray images captured from a plurality of perspective directions.

Preferably, the reconstructed image includes a tomographic image of a cross section parallel to the substrate which is a portion of the inspection target which is a blind spot in the first and second visible light images.

Preferably, the X-ray image is an X-ray image of the object to be inspected.

According to the invention, since the X-ray image is superimposed on the visible light image and the inspection position is displayed, the user can grasp the relationship between the inspection object and the inspection position, and has an effect of being easily visually recognized by the user.

[Formation of the Invention]

Embodiments of the present invention will be described below with reference to the drawings. In the following description, the same reference numerals are attached to the same parts. Its name and function are also the same. Therefore, the detailed description will not be repeated for them. Further, in the present specification, the X-axis, the Y-axis, and the Z-axis are regarded as axes perpendicular to each other.

(structure summary)

The structure of the X-ray inspection apparatus 100 of the present embodiment will be described with reference to Fig. 1 . Fig. 1 is a schematic block diagram of an X-ray inspection apparatus 100 of the present embodiment.

The X-ray inspection apparatus 100 includes an X-ray source 10 that outputs X-rays 18, an X-ray detector 23, an image acquisition control unit 30, and an inspection target drive mechanism 110 that moves the position of the inspection object 1. Further, the X-ray inspection apparatus 100 includes an input unit 40, an output unit 50, an X-ray source control unit 60, a displacement meter 114, an optical camera 116 (not shown), an inspection target position control unit 120, an arithmetic unit 70, and a memory unit. 90. Further, the X-ray inspection apparatus 100 includes an inspection target database (hereinafter referred to as "inspection target DB") 200 for storing the model number of the electronic component mounted on the substrate to be inspected based on CAD (Computer Aided Design) data or the like. The information about the placement position of the part itself, the arrangement direction, the part size, and the electrode pad arrangement for soldering in the substrate (that is, the arrangement of the position to be soldered).

Further, the displacement meter 114 and the optical camera 116 will be described in detail later.

The inspection object 1 is disposed between the X light source 10 and the X-ray detector 23. In the present embodiment, the inspection object 1 is a circuit board on which components are mounted. Further, in the first drawing, the X-ray source 10, the inspection object 1, and the X-ray detector 23 are provided in the order of the lower order, but the X-ray detector 23 may be used in the order of maintenance of the X-ray source. The order of the inspection object 1 and the X light source 10 is configured.

The X light source 10 is controlled by the X-ray source control unit 60, and irradiates the X-ray 18 to the inspection object 1. In the present embodiment, the inspection object 1 is a substrate on which circuit components are mounted. Although not particularly limited, the X-ray source 10 can also be made to scan a X-ray source that can move the focus position on the target in accordance with control from the outside.

The inspection object 1 is moved by the inspection object drive mechanism 110. The specific structure of the inspection target drive mechanism 110 will be described later. The inspection target position control unit 120 controls the operation of the inspection target drive mechanism 110 in accordance with an instruction from the calculation unit 70.

The X-ray detector 23 is a two-dimensional X-ray detector that detects X-rays output from the X-ray source 10 and penetrates the inspection object 1 and visualizes them. As the X-ray detector 23, an I.I. (Image Intensifier) tube or an FPD (Flat Panel Detector) can be used. From the viewpoint of the installation space, it is preferable to use the FPD in the X-ray detector 23. Further, the X-ray detector 23 is preferably of high sensitivity, and is particularly preferably an FPD using a direct conversion method of CdTe, which can be used in an in-line inspection.

The image acquisition control mechanism 30 includes a detector drive control mechanism 32. And the image data acquisition unit 34. The detector drive control unit 32 controls the operation of the X-ray detector 22 to move the X-ray detector 23 in accordance with an instruction from the calculation unit 70. The video data acquisition unit 34 acquires video data of the X-ray detector 23 designated by the calculation unit 70.

The input unit 40 is an operation input device for accepting an input instruction from a user or the like. The output unit 50 is a device that outputs a measurement result or the like to the outside. In the present embodiment, the output unit 50 is a display for displaying an X-ray image or the like constituted by the calculation unit 70.

In other words, the user can execute various types of input via the input unit 40, and various calculation results obtained by the processing of the calculation unit 70 are displayed on the output unit 50. The video displayed on the output unit 50 may be outputted so that the user can judge whether it is good or not by visual observation, or output as a result of the quality determination of the quality determination unit 78 described later.

The X-ray source control unit 60 includes an electron beam control unit 62 that controls the output of the electron beam. The electron beam control unit 62 receives the X-ray focus position and the X-ray energy (tube voltage, tube current) from the calculation unit 70. The specified X-ray energy varies depending on the structure of the inspection object.

The calculation unit 70 executes the program 96 stored in the storage unit 90 to control each unit, and executes predetermined calculation processing. The calculation unit 70 includes an X-ray source control unit 72, a video acquisition control unit 74, a reconstruction unit 76, a quality determination unit 78, an inspection target position control unit 80, an X-ray focus position calculation unit 82, an imaging condition setting unit 84, and inspection information generation. Department 86.

The X-ray source control unit 72 determines the X-ray focus position and the X-ray energy, and transmits a command to the X-ray source control unit 60.

The video acquisition control unit 74 transmits a command to the video acquisition control unit 30 to cause the X-ray detector 23 to acquire an image. Further, the video acquisition control unit 74 acquires video data from the video acquisition control unit 30.

The reconstruction unit 76 reconstructs the plurality of pieces of image data acquired by the image acquisition control unit 74 to form three-dimensional data.

The quality determination unit 78 determines the height (substrate height) of the substrate surface of the mounting component, and determines whether or not the inspection target is good or not based on the tomographic image of the substrate height. Further, the algorithm for determining the quality of the algorithm or the input information for the algorithm varies depending on the object to be inspected. Therefore, the quality determination unit 78 acquires the information from the imaging condition information 94.

The inspection target position control unit 80 controls the inspection target drive mechanism 110 via the inspection target position control mechanism 120.

When the X-ray focus position calculating unit 82 checks the inspection region of the inspection object 1, the X-ray focal position, the irradiation angle, and the like of the inspection region are calculated.

The imaging condition setting unit 84 sets a condition (for example, an applied voltage to the X light source, an imaging time, and the like) when the X-ray source 10 outputs X-rays in accordance with the inspection target 1 .

The memory unit 90 includes X-ray focus position information 92, imaging condition information 94, a program 96 for realizing the functions performed by the calculation unit 70, and image data 98 captured by the X-ray detector 23. The X-ray focus position information 92 includes the X-ray focus position calculated by the X-ray focus position calculating unit 82. The shooting condition information 94 includes information related to the shooting conditions set by the shooting condition setting unit 84 or the algorithm for determining the quality.

Further, the storage unit 90 and the inspection target DB 200 may be used as long as they are usable for storing data. The memory unit 90, for example, by RAM (Random) Memory device such as Access Memory) or EEPROM (Electrically Erasable and Programmable Read-Only Memory) or HDD (Hard Disc Drive). The inspection object DB 200 may also be an HDD, or may be a memory device provided on another computer connected by a network.

(concrete structure)

The specific structure of the X-ray inspection apparatus 100 of the present embodiment will be described with reference to Fig. 2 . Fig. 2 is a view for explaining the structure of the X-ray inspection apparatus 100 of the present embodiment. In the second drawing, the same reference numerals are given to the same portions as those in the first embodiment. In addition, in the second drawing, the portion which is directly related to the control of the X-ray focus position, the control of the X-ray detector position, the control of the inspection target position, and the like among the portions shown in Fig. 1 is extracted and described. .

In the present embodiment, the X light source 10 is a cone beam type light source. Further, as described above, the X-ray source 10 may be a scanning X-ray source that can scan a position (X-ray focal position) at which X-rays are generated in a predetermined direction. The X-ray source 10 generates X-rays in accordance with an instruction from the calculation unit 70 of the X-ray source control unit 60.

The X-ray source 10 is a sealed X-ray source and is mounted above or below the X-ray inspection apparatus 100. Moreover, the target of the X-ray source 10 may be a transmissive type or a reflective type. The X-ray source 10 is attached to an actuator (not shown) and is movable in the vertical direction.

The X-ray detector 23 is disposed at a position facing the X-ray source 10 so as to sandwich the inspection object 1 (substrate). The X-ray detector 23 images the X-rays irradiated by the X-ray source 10. Further, the X-ray detector 23 is attached to the X-ray detector driving unit 22. The X-ray detector driving unit 22 is a three-dimensional pedestal that can move the X-ray detector 23 in the horizontal direction and the vertical direction.

The inspection object drive mechanism 110 is disposed between the X-ray source 10 and the X-ray detector 23. The inspection target drive mechanism 110 includes pedestals 111a and 111b and substrate rails 112a and 112b attached to the pedestals 111a and 111b. The pedestals 111a, 111b can move the inspection object 1 in parallel in the horizontal direction. The substrate rails 112a and 112b sandwich the inspection object 1 from above to below to fix the substrate.

The operations of the pedestals 111a and 111b and the substrate rails 112a and 112b are controlled by the substrate drive control unit 126.

Referring to Fig. 2, the X-ray inspection apparatus 100 includes a displacement meter 114 and an optical camera 116 (not shown in Fig. 1). Displacement meter 114 measures the distance to the substrate. Therefore, the displacement meter 114 can measure the substrate warpage detailed later. The optical camera 116 photographs the substrate with visible light. The optical camera 116 is used to capture a landmark for checking the setting of the position. The displacement meter 114 and the optical camera 116 are retracted to an area where X-rays are not irradiated by the retracting mechanism to avoid exposure to X-rays when photographing with X-rays.

Further, the optical device 116 is mounted with an illumination device 115 by a mounting mechanism (not shown). The illumination device 115 uniformly lights the entire field of view (photographing area) of the optical camera 116. In the present embodiment, the illumination device 115 is a light-emitting diode (Light Emitting Diode) light source that emits white light, but is not limited thereto, and may be another light source. Moreover, it is not necessary to be integrated with the optical camera 116, and it may be designed to be independent of the optical camera 116. Further, similarly to the optical camera 116 and the like, the illumination device 115 is evacuated to an area where X-rays are not irradiated by a retracting mechanism (not shown) to avoid exposure to X-rays when X-rays are used for imaging.

According to the above configuration, the X-ray inspection apparatus 100 can change the ratio (magnification) of the distance between the light source and the substrate and the distance between the light source and the detector. Therefore, X-ray inspection The inspection device 100 can change the size of the inspection object 1 imaged by the X-ray detector 23 (so that the resolution can be changed).

Further, the X-ray inspection apparatus 100 can operate the substrate and the X-ray detector 23 so that the substrate can be imaged from various directions. In the present embodiment, the three-dimensional data of the inspection object 1 is generated by a three-dimensional data generation method called CT (Computed Tomography) based on the imaging results from the respective directions.

Further, in the present embodiment, the X-ray inspection apparatus 100 is used for in-line inspection. For in-line inspection, the inspection object drive mechanism further includes a mechanism for moving the substrate into and out of the substrate. However, such a substrate moving in and out mechanism is not shown in Fig. 2. Generally, a transport belt disposed on a substrate track is used as a moving in and out device of the substrate. Alternatively, a stick called a pusher may be used as the move in and out device. The substrate is slid on the rail by the push rod, whereby the substrate can be moved.

As the calculation unit 70, a general central processing unit (CPU) can be used. The memory unit 90 includes a main memory unit 90a and an auxiliary memory unit 90b. For example, a memory can be used as the main memory unit 90a, and an HDD (Hard Disc Drive) can be used as the auxiliary memory unit 90b. That is, a general computer can be used as the calculation unit 70 and the storage unit 90.

(the process of teaching and processing)

In the following, the operation of the X-ray inspection apparatus 100 of the present embodiment will be described by taking a printed circuit board on which the electronic component as the inspection target is mounted on the front side and the back side.

In the X-ray inspection apparatus 100, the inspection target 1 can input information for teaching the inspection position and the like of the inspection object 1 in advance. The content of the process (teaching process) for inputting such information will be described with reference to FIG. 3 which is a flowchart of the process. Further, in the X-ray inspection apparatus 100, the teaching processing is realized by the information generating unit 86. Further, the information about the inspection instruction generated in the teaching process is stored in the storage unit 90 as, for example, the shooting condition information 94.

Fig. 3 is a flow chart for explaining the flow of the teaching process in the embodiment.

Referring to Fig. 3, when the teaching process is started (S100), first, the substrate to be inspected is moved in the back state (the direction in which the back surface faces the optical camera 116 side) (S102).

Next, in the X-ray inspection apparatus 100, the visible light image is captured by the optical camera 116 in a state where the substrate is facing away (S104). Thereafter, the substrate is temporarily removed from the driving range in which the visible light image can be captured (S106), and the direction is reversed by a predetermined inversion mechanism (not shown in FIGS. 1 and 2), and the substrate is moved in a state in which the substrate is facing. (S108), the visible light image is captured by the optical camera 116 in a state where the substrate is facing (S112).

Next, an X-ray image is taken while the substrate is facing (S112).

As described above, since the visible light image on the front side of the substrate and the visible light image on the back side are captured, and the X-ray image is captured, the image alignment of the three is performed under the control of the calculation unit 70 of the X-ray inspection apparatus 100 ( S114) Next, image expansion and contraction (magnification change) and overlap processing (S116) are performed. Thereafter, the output unit 50 displays the superimposed video image under the control of the arithmetic unit 70 (S118). Although it is not particularly limited, it is described by taking an image in which a visible light image on the front side and an X-ray image are superimposed.

Here, based on the information stored in the inspection target DB 200, the superimposed video as described above is further superimposed, and the mark of the position of the inspection object (here, referred to as the welding ball) of the component attached to the front side is displayed, for example, a rectangular mark. And display. Here, the user judges whether the position of the mark is suitable as an inspection area (referred to as an "inspection window") based on the display, and if so, performs confirmation to confirm the inspection window. Further, if it is not suitable, for example, the position and direction of the inspection window are manually moved to the position and direction determined to be appropriate, and then the confirmation input is performed. Based on the confirmation input, the calculation unit 70 stores the relative position of the inspection window with respect to the inspection target component on the front side as setting information as the imaging condition information of the storage unit 90. In this case, for example, although not particularly limited, in the storage unit 90, the inspection window is set as a relative position with respect to a predetermined reference point (a predetermined angular portion of the part outer shape) of the component (S120).

Then, the output from the output unit 50 is switched to the display on the back side by the control of the calculation unit 70 (S122), and the superimposed image on the back side is displayed in the same manner as the front side (S124), and is stored in the inspection target DB 200. The information is further overlapped in the superimposed image as described above, and the mark (inspection window) indicating the position of the inspection object (here, the welding ball) of the component mounted on the back side is also displayed. Here, the user also judges whether the position of the mark is suitable as an inspection window according to the display, and if appropriate, performs confirmation input for determining the inspection window. Further, if it is not suitable, for example, the position and direction of the inspection window are manually moved to the position and direction determined to be appropriate, and then the confirmation input is made. Based on such confirmation input, the calculation unit 70 also compares the inspection window with respect to the back side. The relative position of the object part is checked as the setting information storage as the shooting condition information of the memory unit 90. In this case, for example, although not particularly limited, in the storage unit 90, the inspection window is set as a relative position with respect to a predetermined reference point of the component (a predetermined angular portion of the component outer shape, etc.) (S126) ).

Next, the user performs setting of the inspection standard described later, attempts to acquire the inspection result, and executes a test for the operation confirmation (S128). Thereafter, the substrate is removed (S130), and the teaching process is ended (S130).

Fig. 4 is a flowchart for explaining "image position superimposition processing (S114)" and "image expansion and superimposition processing (S116)" shown in Fig. 3.

In the following description, the optical magnification of the optical camera and the X-ray camera (for the sake of convenience, the structure of the X-ray image captured by the X-ray detector 23 is referred to as "X-ray camera") is manufactured. When assembling, it is set to a predetermined value in advance. The performance of the optical camera and the X-ray camera is set to, for example, the following values.

Optical camera: resolution: 22μm

X-ray camera: resolution: variable 10, 15, 20, 25, 30μm

Among them, the resolution of the X-ray camera for window setting for teaching is 20 μm. That is, the resolution of the optical camera and the X-ray camera does not necessarily coincide. Further, at the time of manufacture, the position on the front side image captured by the optical camera and the position on the image captured by the X-ray camera corresponding thereto are corrected to be identical.

Therefore, as explained below, the image of the optical camera is enlarged to match the resolution of the X-ray camera by 20 μm. Moreover, in consideration of the relationship between the two degrees of resolution, there is a need to reduce the image of the optical camera.

Referring to Fig. 4, in the above example, the magnification of magnification is performed on the basis of the image center of the visible light image (front side) (S200).

The size of the optical camera image (overlapping image) = the size of the optical camera image (original) × 22/20

Next, the visible light image (front side) and the X-ray image are superimposed on each other (S202).

Here, as the position reference of such overlap, for example, a base can be used. The base mark is formed in a copper wiring pattern at one end in the diagonal direction of the substrate. Therefore, the position of the device can be determined without any error in the copper wiring pattern of the printed circuit board without being affected by the shape of the substrate or the offset of the position at which the wiring is formed on the substrate.

Next, a predetermined base position (for example, a substrate angle on the upper left side of the substrate side) is detected from the image of the visible light image (front side) (S204), and the position A on the image of the "substrate angle on the upper left side of the substrate" thus captured is stored. In the memory unit 90 (S206).

Moreover, the same image enlargement process as that of the front side is performed on the basis of the image center of the visible light image (back side) (S201).

Next, a predetermined base position (for example, a substrate angle on the upper left side of the substrate) is detected from the image of the visible light image (back side) (S212), and the image of the substrate angle on the upper left side of the substrate is thus captured. The difference (Δ(x, y)) from the position A is stored in the memory unit 90 (S212).

For the image on the back side, only the visible light image (back side) and the X-ray image are shifted (Δ(x, y)), and the two are overlapped (S124).

As described above, in the present embodiment, the position of the visible light image and the X-ray image are superimposed on the basis of the substrate angle in the visible light image on the surface. And the location of the specific inspection window. Since the specific position is registered as the relative coordinate of the part, even if it is registered as such, it will be registered with the reference coordinate of the part (the coordinate based on the base mark).

In the CAD data, the part number, the coordinate (X, Y) of the part center, and the rotation angle θ of the part are registered for each part mounted on the printed circuit board. Here, the inspection window is the welding area to be inspected, and is registered in accordance with the number of each part (the type of each part).

Further, in the present embodiment, as will be described later, at the time of inspection, after the substrate is moved in, the imaging of the fiducial mark and the measurement of the height of the substrate are performed. Since the measurement of the height of the substrate is performed, when the X-ray image is a CT image (reconstructed image), the image of the welded portion of the surface can be displayed by displaying a predetermined height profile from the measured substrate height. Further, information on the height of the substrate and the thickness of the substrate is displayed by [(measured substrate height) - (substrate thickness) - (predetermined height)] when the X-ray image is a reconstructed image (CT image) The profile shows the image of the back weld.

Fig. 5 is a conceptual diagram for explaining the alignment of the visible light image on the front side of the substrate and the visible light image on the back side and the X-ray image.

As a premise, as described above, when the relative position of the optical camera and the X-ray camera is manufactured and assembled, the offset is adjusted in advance, and the offset value is corrected so that the position on the front side image captured by the optical camera corresponds to The position on the image captured by the X-ray camera is the same.

Next, as shown in FIG. 5, the visible light image (front side) is aligned with the visible light image (front side) as a reference, and since the substrate is not replaced, the positions of the visible light image (front side) and the X-ray image naturally overlap. Here, X-ray The image may be a single X-ray penetrating image or a reconstructed image (CT image) reconstructed from a plurality of X-ray penetrating images taken from the same direction in multiple directions.

Fig. 6 is a view showing an example of a screen in which the optical image transmittance (the penetration ratio when the superimposed X-ray image is displayed in a manner of being seen through the visible light image) is displayed when the visible light image and the X-ray image are superimposed and displayed.

As shown in Fig. 6, by setting the transmittance to an appropriate value before or after the event, as will be described later, the visibility of the inspection target area when the visible light image and the X-ray image are superimposed and displayed is improved.

Further, the parameters that can be set by the buttons existing in Fig. 6 are as follows.

Fig. 7 is a view showing a display example in which a visible light image (front side) and an X-ray reconstruction image are superimposed and displayed.

As shown in FIG. 7, the visible light image (the front side) photographed from the upper side of the front side is superimposed and displayed on the plane image of the X-ray reconstructed image parallel to the substrate direction and located at a height specified from the surface of the substrate, and is also displayed together. The X-rays then constitute a reconstructed image of the profile specified in the planar image of the image.

Further, in the image in which the visible light image (the front side) captured from the upper side of the front side and the X-ray reconstructed image are superimposed on the image, the position of the welding electrode pad (land: end face) on the substrate (front side) is based on the CAD data. Displayed in a rectangular shape. Also, for the parts set in advance, the rectangular shape window (inspection window) is automatically displayed on the "camera image" screen. If it is not set beforehand, it can also be set manually by the user.

The user can perform a confirmation input after performing the position adjustment of the rectangular shape as needed (for example, clicking the save button).

For the visible light image (back side) and X-ray reconstruction image, the same image display and position adjustment are performed beforehand. Moreover, according to the switching between the front side display and the back side display, the display of the X-ray reconstructed image is also switched to match the display direction.

Fig. 8 is a view showing a display example for further reducing the image shown in Fig. 7 and confirming the welding position of the entire semiconductor wafer.

Fig. 9 is a view showing a display example in which a visible light image (back side) is superimposed on a part number.

Fig. 10 is a view showing a display example in which a visible light image (back side) and an X-ray transmission image are superimposed and displayed.

To make the X-ray reconstitute the image display or to make the X-ray penetrate the image display, it can be set according to the user's choice.

By switching the label, for the visible light image, the front side or the back side of the display substrate can be switched.

According to the display of the display on the front side and the back side, the display of the X-ray penetrating image can also be switched to match the display direction.

Figure 11 is the same as Figure 10 showing the visible light image (back side) and A diagram of a display example in which an X-ray transmission image is superimposed and displayed.

In Fig. 11, in the image displayed by superimposing the visible light image (the front side) and the X-ray penetrating image taken from the upper side of the front side, the electrode pads for welding (land: end face) on the substrate (front side) are based on the CAD data. The position is displayed in a rectangular shape.

The user can perform a confirmation input after performing the position adjustment of the rectangular shape as needed (for example, clicking the save button).

Through the above processing, the position where the visible light image and the X-ray image are superimposed and displayed can be confirmed for the image. At this time, since there is an X-ray image, the welded region is visible to the user, and it can be confirmed that the position of the electrode pad (land: end face) for soldering on the substrate coincides with the CAD data.

(check the processing flow)

Fig. 12 is a view showing the flow of the X-ray inspection of the present embodiment in the form of a flowchart. The flow of the entire X-ray inspection of the present embodiment will be described with reference to Fig. 12 .

Referring to Fig. 12, first, when the processing is started (step SA1), the X-ray inspection apparatus 100 facilitates the movement of the substrate into a predetermined position inside the X-ray inspection apparatus 100 by the inspection target drive mechanism (step SA3). The predetermined position is usually preferably set in the center of the X-ray inspection apparatus 100, that is, in the center of the X-ray irradiation range. However, the predetermined position may also be a position at which the X-ray detector 23 can take an X-ray image of the substrate.

At step SA5, the X-ray inspection apparatus 100 photographs the base using the optical camera 116. Further, the X-ray inspection apparatus 100 corrects the position of the substrate as necessary depending on the position of the base mark. Specifically, the X-ray inspection apparatus 100 moves the substrate position as in the case of moving in. By this processing, the X-ray inspection apparatus 100 can The substrate position shift or the substrate tilt generated when the substrate is moved in is recognized, and the offset and tilt can be corrected.

In step SA7, the X-ray inspection apparatus 100 measures the height of the substrate in the reconstructed region (hereinafter also referred to as a field of view) using the displacement meter 114. The X-ray inspection apparatus 100 stores the measured substrate height in advance in the main memory unit 90a. The stored substrate height is used for CT shooting as described later.

When the inspection object 1 includes a plurality of fields of view, the X-ray inspection apparatus 100 measures the substrate height for all the fields of view before performing CT imaging. This is because the CT must be retracted in order not to expose the displacement gauge 114 during CT imaging. By measuring all the substrate heights in advance, the height of the substrate can be measured every time CT imaging is performed for each field of view, and the entire inspection time can be shortened.

In step SA9, the X-ray inspection apparatus 100 takes one field of view from a plurality of directions in the inspection object 1. In the present embodiment, the X-ray inspection apparatus 100 moves the substrate and the X-ray detector 23 so that the circular orbit is drawn in the horizontal direction, and captures the field of view from a plurality of directions. The position of the substrate and the X-ray detector 23 at the time of imaging is determined by the irradiation angle θR, the distance between the light source and the substrate (FOD), and the distance between the light source and the detector (FID). The substrate and the X-ray detector 23 are arranged to capture the center of the field of view at the center of the X-ray detector 23. Further, the track of the substrate and the X-ray detector 23 may not be circular, and may be rectangular or straight.

The number of shots can be set by the user. Preferably, the user determines the number of shots based on the precision of the reconstructed data obtained. The number of shots is usually around 4~256. However, the number of shots is not limited to this. For example, the X-ray inspection apparatus 100 can of course take more than 256 images.

At step SA11, the X-ray inspection apparatus 100 takes a photograph from multiple directions. Like generating reconstituted material. For the reconstitution process, various methods have been proposed, and for example, the Feldkamp method can be used.

In step SA13, the X-ray inspection apparatus 100 captures the height of the substrate, that is, the height of the surface of the substrate on which the component is placed. The details of the processing performed in step SA13 will be described later.

In step SA15, the X-ray inspection apparatus 100 acquires a tomographic image having a height at a predetermined distance from the substrate in the height direction as an inspection image for inspection. Here, the distance between the height of the image and the height of the substrate is checked by the user. Moreover, this distance is preferably set in accordance with the design data and the inspection method of the inspection object 1. In the present embodiment, on the side where the component is placed, the tomographic image at a height slightly away from the surface of the substrate on which the component is placed is set as the inspection image.

In step SA17, the X-ray inspection apparatus 100 determines whether or not the visual field is good or bad using the inspection image. In other words, the X-ray inspection apparatus 100 checks the wettability of the welded after heating, the presence or absence of the welded hole and the welded bridge, and the presence or absence of foreign matter. Various kinds of good or bad determination methods are known, and the X-ray inspection apparatus 100 may use a good or bad determination method suitable for an inspection item.

In the present embodiment, the quality determination unit 78 determines whether or not the mounting substrate is good or not based on the welding area in the binarized image. Hereinafter, the aspect of the determination of the quality of the substrate in the present embodiment will be described with reference to Fig. 13. Figure 13 is a diagram for explaining the determination of the quality of the welded area in the binarized image.

Fig. 13(A) is a perspective view of the substrate on which the electronic component is mounted. The first component 502 and the second component 503 are attached to the substrate 501. The second part 503 is physically and electrically transmitted through a BGA (Ball Grid Array) 504 or the like. Connected to the substrate 501.

Fig. 13(B) is a cross-sectional view showing the connection between the substrate 501 and the second member 503 in a cross section perpendicular to the surface of the substrate 501. The BGA 504 connects the second part 503 and the surface layer 505 of the substrate 501. The BGA 504 is thermally deformed into a heated state 506. However, the hole 507 is sometimes created in the heated state 506. Further, a plurality of solder balls (hereinafter also referred to as "ball terminals") sometimes combine to form a solder bridge 508.

When the X-ray inspection apparatus 100 includes a welding bridge, three-dimensional data of a desired area is generated, and three-dimensional data is cut to form a tomographic image. The X-ray inspection apparatus 100 binarizes the formed tomographic image, and separates the image into a binary image other than the welding and the bonding. In this binary processing, a general binary processing such as a discriminant analysis method can be used. The inspection device marks the white (or 1) portion from the binarized image to obtain a distinctive image of the weld. In this labeling process, general labeling processing such as determining whether or not there is a link by raster scanning can be used.

An example of a cross section parallel to the surface of the substrate 501 is shown in Fig. 13(C). Fig. 13(C) is a cross-sectional view of the joint cut by the cross section indicated by the broken line in Fig. 13(B). In the 13th (C) diagram, the welding is indicated by white, and the welding is indicated by oblique lines. Here, three states of normal, hole, and welded bridge are shown. Referring to Fig. 13(C), in the case of the hole 507, a portion having no weld is generated in the weld. In the case of the welded bridge 508, the welding is observed in a wider area than normal.

The inspection device calculates the area of the individual welds (the number of white or 1 pixels) from the mark image and obtains the area of the weld. The inspection device is considered to be a good product as long as the area is within a certain range, and is regarded as a defective product. In this way, the quality of the welded joint is determined. The threshold of this range is generally preset by the user.

Returning to Fig. 12, in step SA18, the X-ray inspection apparatus 100 determines whether or not the quality of all the visual fields is determined. When there is a field of view in which the determination is not made, (NO in step SA18), the X-ray inspection apparatus 100 repeats the processing from the CT imaging (step SA9). When the quality of all the fields of view is determined (YES in step SA18), the process proceeds to step SA19.

At step SA19, the X-ray inspection apparatus 100 removes the substrate from the X-ray inspection apparatus 100. Specifically, the X-ray inspection apparatus 100 moves the substrate outside the X-ray inspection apparatus 100 by the inspection target drive mechanism 110.

As described above, the X-ray inspection apparatus 100 completes the inspection of one inspection object 1 (step SA21). When the X-ray inspection apparatus 100 performs the in-line inspection on the plurality of inspection objects 1, the series of processing from step SA1 to step SA21 described so far is repeated.

Fig. 14 is a conceptual diagram for explaining other configurations of the X-ray inspection apparatus 100.

In the structure shown in FIG. 1, the inspection target DB 200 is configured to be disposed inside the X-ray inspection apparatus 100.

However, if the X-ray inspection apparatus 100 is used in a line, it is not necessary to store CAD data or the like in the X-ray inspection apparatus 100, and as shown in Fig. 14, it may be connected by a network and disposed outside the production line. In the data creation device, the inspection object DB 200 is stored.

According to the configuration of the X-ray inspection apparatus 100 of the present embodiment as described above, the X-ray image is superimposed on the visible light image and the inspection position is displayed. Therefore, the user can grasp the relationship between the inspection object (for example, the welding ball) and the inspection position, and has an effect that the user can easily visually recognize.

Further, the surface and the back surface can be aligned and the inspection position can be determined, and the alignment of the surface and the back surface can be performed with good precision.

Moreover, since the CT tomographic image related to the surface/back surface is displayed, it is easier to distinguish the object from the surface/back surface.

The embodiments disclosed herein are to be considered as illustrative and not restrictive. The scope of the present invention is defined by the scope of the claims and the scope of the claims and the scope of the invention.

1‧‧‧Check objects

10‧‧‧X source

12‧‧‧Substrate

18‧‧‧X-ray

22‧‧‧X-ray detector drive unit

23‧‧‧X-ray detector

30‧‧‧Image acquisition control agency

32‧‧‧Detector drive control mechanism

34‧‧‧Image Data Acquisition Department

40‧‧‧ Input Department

50‧‧‧Output Department

60‧‧‧X light source control mechanism

62‧‧‧Electronic Beam Control Department

70‧‧‧ Calculation Department

72‧‧‧X Light Source Control Department

74‧‧‧Image Acquisition Control Department

76‧‧‧Reconstitution

78‧‧‧Good and bad judgment department

80‧‧‧Check object position control unit

82‧‧‧X-ray focus position calculation unit

84‧‧‧Photographing conditions setting section

86‧‧‧Check information generation department

90‧‧‧Memory Department

92‧‧‧X-ray focus position information

94‧‧‧ shooting conditions information

96‧‧‧Program

98‧‧‧Image data

100‧‧‧X-ray inspection device

110‧‧‧Check object position drive mechanism

111a, 111b‧‧‧ pedestal

112a, 112b‧‧‧ substrate track

114‧‧‧displacement meter

116‧‧‧Optical camera

120‧‧‧Check object position control mechanism

Fig. 1 is a schematic block diagram of an X-ray inspection apparatus 100 according to the present embodiment.

Fig. 2 is a view for explaining the structure of the X-ray inspection apparatus 100 of the embodiment.

Fig. 3 is a flow chart for explaining the flow of the teaching process in the embodiment.

Fig. 4 is a flow chart for explaining "image matching processing (S114)" and "image stretching and superimposing processing (S116)" shown in Fig. 3.

Fig. 5 is a conceptual diagram for explaining the alignment of the visible light image on the front side of the substrate and the visible light image on the back side and the X-ray image.

Fig. 6 is a view showing an example of a screen for setting the optical image transmittance when the visible light image and the X-ray image are superimposed and displayed.

Fig. 7 is a view showing a display example in which a visible light image (front side) and an X-ray reconstruction image are superimposed and displayed.

Fig. 8 is a view showing a display example for further reducing the image shown in Fig. 7 and confirming the welding position of the entire semiconductor wafer.

Fig. 9 is a view showing a display example in which a visible light image (back side) is superimposed on a part number.

Fig. 10 is a view showing a display example in which a visible light image (back side) and an X-ray transmission image are superimposed and displayed.

Fig. 11 is a view showing a display example in which a visible light image (back side) and an X-ray transmission image are superimposed and displayed in the same manner as in Fig. 10.

Fig. 12 is a view showing the flow of the X-ray inspection of the present embodiment in the form of a flowchart.

Fig. 13 is a view for explaining the determination of the quality of the welded area in the binarized image.

Fig. 14 is a conceptual diagram for explaining another configuration of the X-ray inspection apparatus 100.

S100‧‧‧ teaching begins

S102‧‧‧ Moving into the substrate (backward)

S104‧‧‧Photographing substrate (back): visible light image

S106‧‧‧Remove the substrate

S108‧‧‧ Move into the substrate (facing)

S110‧‧‧Photographing substrate (surface): visible light image

S112‧‧‧Photographing substrate: X-ray image

S114‧‧‧Overlapping image position

S116‧‧‧ Telescopic, overlapping images

S118‧‧‧Display overlay image (for surface)

S120‧‧‧Set surface window (manual or CAD mode)

S122‧‧‧Switch to back display

S124‧‧‧Display overlay image (for back)

S126‧‧‧Set back window (manual or CAD mode)

S128‧‧‧Setting, test and inspection criteria

S130‧‧‧Remove the substrate

S132‧‧‧Teaching ends

Claims (10)

In an X-ray inspection apparatus that performs inspection of an inspection object using X-rays, an inspection area to be inspected is set, and the inspection area includes the first step of inspecting the inspection target including the inspection object. a step of capturing a visible light image of the region; and performing a X-ray image capturing process on the second region of the inspection target including the inspection object; and the visible light image of the first region and the X of the second region The optical image is displayed simultaneously with the mark indicating the position of the inspection object when the position and the magnification are the same; and the position of the mark to be displayed and the position of the test object of the X-ray image are accepted The step of determining the aforementioned inspection area by the input of the confirmation. The method for setting an inspection region according to the first aspect of the invention, wherein the object to be inspected is a substrate on which a plurality of electronic components are arranged, and the step of capturing the visible light image includes capturing a first visible light image and a back side of a surface side of the substrate. The step of displaying the second visible light image; the step of simultaneously displaying the step of displaying the first or second visible light image when the X-ray image is aligned with the position and the magnification; and the determining step The step of determining the aforementioned inspection regions of each of the front side and the back side is included. The method for setting an inspection area according to item 2 of the patent application scope, wherein the foregoing The X-ray image includes a reconstructed image of the region of the inspection target based on the plurality of X-ray images captured from a plurality of perspective directions. The method for setting an inspection region according to the third aspect of the invention, wherein the reconstructed image includes a tomographic image of a cross section parallel to the substrate in a portion of the inspection target that is a blind spot in the first and second visible light images. The method for setting an inspection region according to the first aspect of the invention, wherein the X-ray image is an X-ray image of the object to be inspected. An X-ray inspection system for detecting an inspection object by X-ray inspection, comprising: a memory means for storing information specifying an inspection target position of the inspection object; and a visible light imaging means for photographing the inspection object including the inspection object The visible light image of the first region; the X-ray image capturing means captures the X-ray image of the second region including the inspection target of the inspection object; and the output means, the visible light image of the first region and the second image The X-ray image of the area is displayed when the position and the magnification are the same, and the mark indicating the position of the inspection object is simultaneously displayed according to the information stored in the memory means; and the input means is for the aforementioned inspection object to be displayed. And the control means inputs the setting information for specifying the determined inspection area to the memory means according to the input. The X-ray inspection system according to the sixth aspect of the invention, wherein the object to be inspected is a substrate in which a plurality of electronic components are disposed; and the visible light image capturing means captures a first visible light image on the front surface side of the substrate and a rear side 2 visible light image; wherein the output means displays any one of the first or second visible light images and the X-ray image at a position and magnification; and the control means is used for a specific surface side and The setting information of each of the aforementioned inspection areas on the back side is stored in the aforementioned memory means. The X-ray inspection system according to claim 7, wherein the X-ray image includes a reconstructed image of a region of the inspection target based on the plurality of X-ray images captured from a plurality of perspective directions. The X-ray inspection system of claim 8, wherein the reconstructed image includes a tomographic image of a cross section parallel to the substrate in a portion of the inspection target that is a blind spot in the first and second visible light images. The X-ray inspection system of claim 6, wherein the X-ray image is an X-ray image of the object to be inspected.