JP6468270B2 - Exposure dose management apparatus and exposure dose management method - Google Patents

Description

  The present invention relates to an industrial X-ray inspection apparatus, and more particularly to a technique for managing the exposure dose of electronic components by X-ray inspection.

  There is known an industrial X-ray inspection apparatus that irradiates an inspection object with X-rays and detects defects and defects of industrial products using transmission images and CT images thereof. Such an X-ray inspection apparatus takes advantage of the ability to non-destructively inspect a portion that is difficult to visually recognize from the appearance and the state of the inside of the object. It is applied to various inspections such as inspection of defects and 100% inspection of electronic devices.

  Even an industrial product such as an electronic device may cause performance deterioration or failure if the exposure dose exceeds an allowable limit. Therefore, it is desirable for manufacturers to appropriately operate the dose, method, and number of X-ray examinations so that the exposure dose does not exceed the allowable limit.

  Among industrial products, special attention is required for electrical / electronic parts (hereinafter simply referred to as “parts”). Because parts often go through multiple X-ray inspection processes, such as inspections at parts manufacturers, inspections at device manufacturers, and inspections at final product manufacturers, the exposure dose in a single manufacturer or process exceeds the allowable limit. This is because even if the amount is lower, there is a possibility that a malfunction may occur if the cumulative exposure amount until the final product is large.

  In addition, when the inspection object is an object including a plurality of components (for example, a surface-mount substrate, an electronic device or its module, a component group loaded on a component tray, etc.), the exposure dose by the X-ray inspection is the inspection object. Not all parts on the object will be the same. In addition, when a plurality of X-ray irradiations are performed in one X-ray inspection, it is assumed that the number of X-ray irradiations and the amount of exposure are different for each part.

  Therefore, conventionally, a method for managing the exposure dose in X-ray inspection for each part has been proposed. For example, in Patent Document 1, component data, irradiation data, and X-ray allowable dose data of each component are stored in a server, and an X-ray irradiation scheduled dose is calculated from the component data and irradiation data. There has been proposed an X-ray imaging apparatus having a function of giving a warning when the value exceeds. Further, Patent Document 2 proposes an X-ray exposure management system having a function of counting estimated exposures for each part at the time of imaging and calculating a cumulative exposure for a target substrate.

JP 2002-350367 A JP2012-163352A

Since X-rays are highly transmissive, parts disposed on the back surface of the substrate are also exposed (in this specification, the surface on the radiation source side of the inspection object is referred to as “surface” or “first surface” for convenience. The surface opposite to the radiation source is referred to as “back surface” or “second surface”.) However, a part of the X-ray energy is absorbed when passing through the front surface component or the printed circuit board itself, and the X-ray attenuates, so that the exposure amount of the back surface component is smaller than that of the front surface component. In addition, the amount of attenuation of X-rays depends on the design of the board (for example, the thickness and material of the printed board, the arrangement of components on the surface, etc.). However, since the conventional technology does not consider any variation in the exposure dose of the back part depending on the design of the substrate, it is difficult to accurately grasp and manage the exposure dose for each component.

  This invention is made | formed in view of the said situation, Comprising: It aims at providing the technique for managing the exposure amount for every component on a test target object appropriately.

  In order to achieve the above object, the present invention is configured to calculate the exposure dose distribution on the radiation source side surface of the inspection object and the exposure dose distribution on the surface opposite to the radiation source, respectively. adopt.

  Specifically, the present invention provides an exposure dose calculation unit that calculates an exposure dose that the inspection target receives by X-ray inspection, and an information output unit that outputs information related to the exposure dose of the inspection target. In the management apparatus, the inspection object includes a plurality of parts, and the exposure amount calculation unit irradiates the positional relationship between the radiation source and the inspection object in the X-ray inspection and the radiation source. Based on the intensity of the X-rays, the distribution of the exposure dose on the first surface that is the surface on the radiation source side of the inspection object and the first surface that is the surface on the opposite side of the radiation source of the inspection object. Exposure dose management that calculates the exposure dose distribution on two surfaces and calculates the exposure dose for each component based on the distribution of the exposure dose on each of the first surface and the second surface and the arrangement of each of the plurality of components. Providing equipment.

  According to this configuration, the exposure of each component is based on the exposure dose distribution on the radiation source side surface (first surface) of the inspection object and the exposure dose distribution on the surface opposite to the radiation source (second surface). Since the amount is calculated, it is possible to accurately calculate the exposure amount of the component on the first surface side and the exposure amount of the component on the second surface side. Therefore, the present invention is for exposure dose management of a double-sided mounting board having a printed circuit board, a component disposed on the first surface of the printed circuit board, and a component disposed on the second surface of the printed circuit board. It can be preferably applied.

  The present invention may be used for predicting the exposure dose or for recording the exposure dose. Prediction of exposure dose is a process of estimating the exposure dose that the inspection object will receive in the X-ray inspection before actually performing the X-ray inspection, and recording the exposure dose means actually performing the X-ray inspection. This is a process for calculating the exposure dose received by the inspection object after it has been performed.

  The exposure dose calculation unit calculates an exposure dose distribution on the second surface in consideration of X-ray absorption by the printed circuit board and / or X-ray absorption by components arranged on the first surface. Good. By taking into account X-ray absorption by the printed circuit board and the components on the first surface side, the intensity of X-rays transmitted to the second surface side, that is, the exposure dose on the second surface can be accurately calculated.

  When a plurality of times of X-ray irradiation are performed in one X-ray examination, the exposure dose calculation unit calculates the exposure dose due to each X-ray irradiation, and cumulatively adds them to obtain one X-ray exposure. It is preferable to calculate the distribution of exposure dose by line inspection. According to this configuration, the exposure dose can be calculated with high precision even when a plurality of X-ray irradiations are performed, for example, when the inspection object is divided into a plurality of fields of view and inspected.

  It is good to further have a judgment part which judges for every part whether it is settled in permissible quantity based on the exposure amount for every part computed by the above-mentioned exposure amount calculation part. For example, the exposure dose is predicted before the X-ray inspection is performed, and if a component exceeding the allowable amount is detected, measures such as changing the X-ray irradiation conditions or stopping the X-ray inspection are taken. be able to.

  An inspection history storage unit that stores a history of X-ray inspections performed on the inspection object in the past, and an exposure dose distribution and / or a component calculated by the exposure dose calculation unit based on the history It is preferable to further include an exposure dose update unit for accumulating the exposure dose by the X-ray examination performed in the past. Thereby, when the inspection object has undergone a plurality of X-ray inspections, it is possible to grasp and manage the distribution of the accumulated exposure dose on the inspection object and the accumulated exposure dose for each part.

  The information output unit may output an exposure dose map indicating a distribution of the exposure dose to the display device. The information output unit may output information indicating an exposure dose for each component to the display device. The information output unit may output information indicating whether or not the exposure dose for each component is an allowable amount to the display device. By providing such information to the user, it becomes easy to grasp and manage the exposure dose of each part of the inspection object.

  In addition, this invention can be grasped | ascertained as an exposure management apparatus which has at least one part of the said structure thru | or function. Moreover, this invention can also be grasped | ascertained as an X-ray inspection system provided with an X-ray inspection apparatus and an exposure dose management apparatus. Moreover, this invention can also be grasped | ascertained as the exposure management method or X-ray inspection method containing at least one part of the said process. The present invention can also be understood as a program for causing a computer to execute each step of these methods, or a computer-readable recording medium in which such a program is recorded non-temporarily. Each of the above configurations and processes can be combined with each other to constitute the present invention as long as there is no technical contradiction.

  According to the present invention, the exposure dose for each part on the inspection object can be appropriately managed.

FIG. 1 is a diagram illustrating a configuration of an X-ray inspection system according to a first embodiment. FIG. 2 is a flowchart of the X-ray inspection. 3A is a plan view of the front surface of the substrate, and FIG. 3B is a plan view of the back surface of the substrate. FIG. 4 is a diagram illustrating an example of X-ray irradiation conditions. 5A to 5C are views showing the state of X-ray irradiation according to the X-ray irradiation conditions of FIG. FIG. 6 is a flowchart of exposure dose calculation processing according to the first embodiment. FIG. 7 is a diagram illustrating an example of X-ray source information. FIG. 8 is a diagram illustrating an example of target information. FIG. 9A and FIG. 9B are diagrams showing display examples of an exposure dose map. FIG. 10 is a diagram showing a tabular display example of the component exposure dose and the determination result. FIG. 11A and FIG. 11B are diagrams showing display examples of the component exposure dose and the determination result in the form of an arrangement diagram. FIG. 12 is a diagram illustrating a configuration of an X-ray inspection system according to the second embodiment. FIG. 13 is a flowchart of exposure dose calculation processing according to the second embodiment.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. However, the description of each configuration described below should be changed as appropriate according to the configuration of the apparatus to which the invention is applied and various conditions, and is intended to limit the scope of the present invention to the following description. Absent.

<First Embodiment>
(X-ray inspection system)
FIG. 1 is a diagram schematically showing the configuration of the X-ray inspection system according to the first embodiment.

  The X-ray inspection system 1 generally includes an X-ray inspection apparatus 10 and an exposure dose management apparatus 11. The X-ray inspection apparatus 10 is an apparatus that performs nondestructive inspection of the inspection object 12 using X-rays. In the present embodiment, an X-ray board inspection apparatus that inspects a solder joint of each component by using a mounting substrate on which a plurality of components are mounted as an inspection object will be exemplified. The exposure dose management device 11 is a device that manages the exposure dose received by the inspection object 12 by X-ray inspection. The X-ray inspection apparatus 10 and the exposure dose management apparatus 11 may be configured as an integrated apparatus, or may be configured as separate apparatuses.

(X-ray inspection equipment)
The X-ray inspection apparatus 10 includes an X-ray source 100, an X-ray detector 101, a stage 102, a control unit 103, an inspection unit 104, a storage unit 105, and the like. The X-ray source 100 is means for irradiating the inspection object 12 with X-rays, and is constituted by, for example, a cone beam type or fan beam type X-ray generator. The X-ray detector 101 is an imaging unit that detects X-rays that have passed through the inspection object 12 and outputs X-ray transmission image data, and includes, for example, a scintillator and a two-dimensional CMOS sensor. The stage 102 is means for holding and transporting the inspection object 12, and aligns the field of view of the imaging system composed of the X-ray source 100 and the X-ray detector 101 and the inspection object area on the inspection object 12. When moving the field of view of the imaging system, the stage 102 may be moved, the imaging system may be moved, or both the stage 102 and the imaging system may be moved.

  The control unit 103 performs operations (movement of the visual field, X-ray irradiation, X-ray transmission image capture, inspection processing in the inspection unit 104, cooperation with external devices, data transmission, etc.) of each part of the X-ray inspection apparatus 10. The unit to control. The inspection unit 104 is a unit that inspects the inspection object 12 using the X-ray transmission image acquired by the X-ray inspection apparatus 10. Here, the functions of the control unit 103 and the inspection unit 104 may be realized by software processing by a computer having a CPU (processor) and a memory, or may be realized by a circuit such as an FPGA or an ASIC.

  The storage unit 105 is a unit that stores data such as a setting file, an inspection program, an X-ray transmission image, and an inspection result of the X-ray inspection apparatus 10. The setting file is data describing common information that does not depend on the inspection object 12 (for example, initial setting values, specifications of the X-ray source 100 and the X-ray detector 101, etc.). The inspection program is data that defines the procedure of the X-ray inspection, and is created and stored in advance for each type of inspection object 12. The inspection program includes information on the inspection object 12 (for example, the size / thickness / material of the substrate, the position / size / allowable exposure amount on the substrate for each component), X-ray irradiation conditions (for example, irradiation position (field of view) Position), distance between the X-ray source and the substrate, tube voltage, tube current, irradiation time, etc.), inspection logic (eg, feature quantity acquired from the image, inspection criteria (threshold value, range)), processing according to the determination result Etc.) should be included. The storage unit 105 is configured by a nonvolatile storage device such as a flash memory or a hard disk.

(Operation of X-ray inspection)
An example of the operation of the X-ray inspection by the X-ray inspection apparatus 10 will be described with reference to the flowchart of FIG.

  First, the control unit 103 reads a setting file from the storage unit 105 and performs initial setting of the X-ray inspection apparatus 10 (step S20). Next, the control unit 103 reads an inspection program corresponding to the type of the inspection object 12 (for example, the product number of the substrate) from the storage unit 105 (step S21). The type of the inspection object 12 may be input by the user, or may be recognized by reading a barcode, a two-dimensional code, an IC tag, or a number printed on the substrate. A notification may be received from an external device (for example, a host system that manages a production line).

  The control unit 103 executes the movement of the field of view of the imaging system, the X-ray irradiation, and the capture of the transmission image in accordance with the X-ray irradiation conditions defined in the inspection program (steps S22 to S24). When a plurality of X-ray irradiation conditions are set in the inspection program, the processes of Steps S22 to S24 are repeatedly executed while sequentially changing the X-ray irradiation conditions (Step S25).

  FIG. 3A and FIG. 3B show an example of a surface mount substrate as the inspection object 12. FIG. 3A is a plan view of the surface of the substrate, and five components 31 to 35 are arranged on the surface. FIG. 3B is a plan view of the back surface of the substrate (however, it is a perspective view seen from the same direction as FIG. 3A), and two components 36 and 37 are arranged on the back surface. FIG. 4 shows an example of the X-ray irradiation conditions set in this substrate inspection program. FIG. 4 shows an example in which X-ray irradiation is performed three times while changing the X-ray irradiation position (field position), the distance between the X-ray source and the substrate, and the tube voltage and tube current conditions of the X-ray source. The unit of tube current “uA” is an abbreviation for microampere. 5A to 5C schematically show the state of X-ray irradiation according to the X-ray irradiation conditions of FIG. The left side of each figure is a side view, the right side is a plan view, and hatching indicates the X-ray irradiation range. By this operation, X-ray transmission images regarding the three fields of numbers 1 to 3 are obtained.

  Subsequently, the inspection unit 104 extracts a necessary feature amount from the X-ray transmission image according to the inspection logic defined in the inspection program, and compares the value of the feature amount with a determination criterion, thereby The quality of the solder joint is determined (step S26). The inspection result by the inspection unit 104 is output to a display device or an external device (step S27).

(About exposure by X-ray examination)
As described above, when the exposure dose of parts exceeds the allowable limit, there is a risk of causing performance degradation or failure. In addition, since a single part often undergoes multiple X-ray inspection processes, such as inspections by component manufacturers, inspections by device manufacturers, and inspections by final product manufacturers, not only the exposure dose in individual processes. It is desirable to make it easy to grasp the final cumulative exposure dose. Therefore, in the X-ray inspection system 1 of the present embodiment, the exposure dose management apparatus 11 predicts and records the exposure dose received by the individual components 31 to 37 on the inspection object 12 by the X-ray inspection by the X-ray inspection apparatus 10. , Output. “Prediction” is a process of estimating the exposure dose received by the inspection object 12 before performing the X-ray inspection. This prediction result can be used, for example, for verifying whether or not the X-ray irradiation conditions are appropriate and for determining whether or not the X-ray inspection of the inspection object 12 may be executed. “Recording” is a process of calculating the exposure dose actually received by the inspection object 12 when an X-ray inspection is performed, and storing it as a log. The recorded log data is disclosed to post-processes, delivery destination manufacturers, consumers, etc. as evidence for certifying the exposure dose of the inspection object 12.

  Here, regarding the inspection object 12 including a plurality of components such as a surface mount substrate, it is preferable to consider the following points when predicting or recording the exposure dose by the X-ray inspection.

  (1) In one X-ray examination, there are many cases where X-ray irradiation is performed a plurality of times while changing the X-ray irradiation conditions. In that case, the number of times of exposure (number of times of receiving X-ray irradiation) and the amount of exposure may differ depending on the part. For example, in the example of FIGS. 5A to 5C, the number of exposures of the component 31 is one time, but the number of exposures of the component 34 is two times. Therefore, for each part, it is necessary to calculate the exposure dose received by each X-ray irradiation and to calculate the total amount.

  (2) The dose within the irradiation range is not constant. Since the intensity of the X-ray is inversely proportional to the square of the propagation distance, for example, in the case of a general cone beam type X-ray source, the dose at the center of the irradiation range is the maximum, and the dose is closer to the end. Get smaller. The distribution of the dose within the irradiation range depends on the specifications of the X-ray source 100 (such as the beam irradiation angle (expansion angle)), the geometric positional relationship between the X-ray source 100 and the inspection object 12, and the irradiation of the X-ray source 100. If conditions (tube voltage, tube current, irradiation time, etc.) are known, calculation is possible.

  (3) Since X-rays are highly transmissive, parts (parts 36 and 37 in FIG. 5A) arranged on the back surface of the substrate are also exposed. However, part of the X-ray energy is absorbed when passing through the front surface component or the printed circuit board, and the X-ray attenuates, so that the exposure amount of the back surface component is smaller than that of the front surface component. In addition, the amount of attenuation of X-rays depends on the design of the board, such as the thickness and material of the printed circuit board, the arrangement of the components on the surface (for example, when passing through a 1 mm thick glass epoxy board, the exposure dose is reduced by about 60% .) Therefore, the exposure amount of the back part should be calculated in consideration of the attenuation of X-rays by the printed circuit board itself and the front part.

  (4) The exposure allowance may vary depending on the type of component. Therefore, it is preferable to manage the exposure amount and the allowable amount for each part.

(Exposure management device)
With reference to FIG. 1, the structure of the exposure dose management apparatus 11 is demonstrated. The exposure dose management apparatus 11 has a data input unit 110, an exposure dose calculation unit 111, a determination unit 112, and an information output unit 113 as its functions. The data input unit 110 is a means for acquiring various data used for exposure dose calculation. The exposure dose calculation unit 111 is a means for calculating the exposure dose that the inspection object receives by the X-ray inspection. The determination unit 112 is a means for determining for each component whether or not the exposure dose is within the allowable amount. The information output unit 113 is means for outputting information related to the exposure dose of the inspection object to the display device 114 or an external device (not shown).

  The exposure dose management apparatus 11 is configured by a general-purpose computer including a CPU (processor), a memory, a storage (such as a hard disk), an input device (such as a keyboard, a mouse, and a touch panel), a display device 114, and a communication I / F, for example. can do. In this case, the exposure dose management apparatus 11 may be configured by one computer, or the exposure dose management apparatus 11 may be realized by cooperation of a plurality of computers. For example, distributed computing or cloud computing technology may be used. Each function of the exposure management apparatus 11 of this embodiment is implement | achieved when a CPU runs the required program. However, part or all of the functions can be configured by a circuit such as an ASIC or FPGA.

(Calculation of exposure dose)
With reference to the flowchart of FIG. 6, an example of the exposure dose calculation processing by the exposure dose management apparatus 11 will be described. Here, the double-sided board shown in FIGS. 3A and 3B is taken as an example, and it is assumed that the X-ray inspection according to the X-ray irradiation conditions shown in FIG. Predict the exposure dose to .about.37.

First, the data input unit 110 acquires data necessary for calculating the exposure dose (step S60). Data necessary for calculating the exposure dose includes, for example, X-ray irradiation conditions, X-ray source information, target information, and the like. The irradiation condition is information for calculating the X-ray irradiation position and intensity, and as shown in FIG. 4 as an example, the irradiation position and X-ray in each X-ray irradiation performed in one X-ray inspection. The distance of the source 100, tube voltage, tube current, irradiation time, etc. may be included. The X-ray source information is information for calculating the shape, size, and intensity distribution of the X-ray irradiation range. In the case of the cone beam type or fan beam type X-ray source 100, as shown in an example in FIG. 7, the beam irradiation angle (expansion angle) may be acquired as the X-ray source information. The object information is information related to the inspection object 12 of the X-ray inspection. An example of the target information regarding the double-sided board shown in FIGS. 3A and 3B is shown in FIG. Here, information on the printed circuit board includes the size, thickness, and material of the board, and information on the component includes the part number, board front / back, position on the board, size, and exposure allowance. Included in the information. The above-described X-ray irradiation conditions, X-ray source information, and target information can be acquired from an inspection program and / or a setting file of the X-ray inspection apparatus 10. In FIG. 1, these pieces of information are acquired from the storage unit 105 of the X-ray inspection apparatus 10, but information is acquired from other apparatuses (such as a host system of the X-ray inspection apparatus 10 and a storage storing data). It doesn't matter.

Next, the exposure dose calculation unit 111 calculates an exposure dose map on the surface of the substrate (surface on the radiation source side) based on the X-ray source information and X-ray irradiation conditions acquired in step S60 (step S61). The exposure map is data representing the exposure dose for each position on the substrate, and is recorded, for example, in the form of two-dimensional image data. The intensity of the X-ray is inversely proportional to the square of the distance from the X-ray source 100, proportional to the square of the tube voltage, proportional to the tube current, and proportional to the irradiation time. Therefore, the exposure value for each position on the substrate can be calculated based on the positional relationship between the X-ray source 100 and the substrate and the intensity of the X-rays emitted from the X-ray source 100. At this time, the exposure dose may be calculated only by theoretical calculation, or the exposure dose may be calculated by correcting the measured value measured in advance under a predetermined condition according to the difference in irradiation condition. . As an example of the latter, there is a method of calculating an exposure dose at a tube current 110 uA as in the following equation when an actual measurement value at a tube current 100 uA is known.

Exposure amount at tube current 110 uA = actual measurement value at tube current 100 uA × correction coefficient 1.1

  When multiple X-ray irradiations are performed in one X-ray examination, that is, when conditions related to a plurality of fields of view are included in the X-ray irradiation conditions, exposure by each X-ray irradiation A dose map is obtained, and a combination (accumulated addition) of them is used as a final exposure dose map.

  Next, the exposure dose calculation unit 111 calculates an exposure dose map on the back surface (surface opposite to the radiation source) of the substrate based on the exposure dose map on the surface calculated in Step S61 and the target information (Step S61). S62). Specifically, the exposure dose calculation unit 111 calculates the absorbed dose by the substrate based on the thickness and material of the substrate, and calculates the absorbed dose by the surface component based on the arrangement of the surface component. Then, the exposure dose calculation unit 111 calculates the exposure dose value on the back surface of the substrate by subtracting the absorbed dose due to the substrate and the absorbed dose due to the surface components from the value of the exposure dose on the surface calculated in step S61.

  Note that the absorbed dose of the substrate may be calculated based on an actually measured value measured in advance, or may be estimated from a result of actual X-ray imaging of a part where no component exists on the substrate. As for the absorbed dose of each component, a predetermined value (fixed value) may be used uniformly, or may be changed according to the component type and component size (height) (for example, the absorbed dose for each component type). May be obtained from the database), and the part where the component exists on the substrate may be estimated from the result of actual X-ray imaging.

  Next, the processes in steps S63 to S65 are repeated for all components on the board (step S66). Hereinafter, the part to be processed is referred to as a target part.

  In step S63, the exposure dose calculation unit 111 calculates the exposure dose of the target component. Specifically, the exposure dose calculation unit 111 calculates a representative value of the exposure dose in the area occupied by the target component using the exposure map of the surface (front surface or back surface) where the target component exists, and calculates the value. The exposure amount of the part of interest. As the representative value, a total value, an average value, a maximum value, an intermediate value, or the like can be used. Of these, a plurality of values (for example, an average value and a maximum value) may be used as an index representing the exposure amount of the target component.

In step S64, the exposure amount calculation unit 111 acquires the exposure allowable amount (see FIG. 8) of the target component from the target information. However, the method for obtaining the exposure allowance is not limited to this. For example, the default value (fixed value) may be applied uniformly for all parts, the exposure allowance for each part type may be acquired from the database, or the part type and part material input as target information The allowable exposure dose may be calculated based on information such as size.

  In step S65, the determination unit 112 compares the exposure amount of the target component calculated in step S63 with the exposure allowable amount of the target component acquired in step S64, and determines whether the exposure amount of the target component is within the allowable exposure amount. Determine whether.

  When the processing of the last component is completed (step S66; YES), the information output unit 113 outputs the exposure amount map of the front and back surfaces of the substrate, the exposure amount of each component, the determination result, and the like to the display device 114 (step). S67).

  9A is a display example of the exposure map on the substrate surface, and FIG. 9B is a display example of the exposure map on the back surface of the substrate. In this example, the magnitude of the exposure dose is represented by a gradation of light and shade, and the exposure dose is smaller as it is closer to white, and the exposure dose is higher as it is closer to black. Moreover, the rectangular frame has shown the arrangement | positioning of each component of the surface and a back surface. With such an exposure map, it is possible to intuitively understand the distribution of the exposure dose on the front surface / back surface of the substrate and the size of the exposure dose of each component. In particular, it is possible to easily determine a portion where the exposure dose is accumulated by multiple times of X-ray irradiation. Further, as shown in FIG. 9B, the exposure dose map in consideration of the absorbed dose of the substrate and the components on the front surface can be shown, so that the exposure dose of the components on the back surface of the substrate can be accurately grasped. The method for illustrating the exposure dose map is not limited to this example, and any method may be used. For example, the magnitude of the exposure dose may be expressed in a pseudo color (also referred to as a heat map) or displayed as a contour graph. Further, an exposure map (computer graphics) may be displayed so as to be superimposed on the image of the substrate.

  FIG. 10 is an example in which the exposure dose and determination result of each component are displayed in a table format. For each part, the part number, the front / back of the board, the exposure amount, and the determination result are shown. For parts whose exposure dose exceeds the allowable amount, an alert may be notified to the user by performing highlighting such as highlighting or blinking as in part number 5.

  FIG. 11A and FIG. 11B are examples in which the exposure dose and determination result of each component are displayed in a layout diagram format. A rectangle indicating each component is shown on each of the front and back surfaces of the substrate, and the exposure dose is shown in the component rectangle. The color (or shading) of the component rectangle represents the amount of exposure. In addition, for parts whose exposure dose exceeds the allowable amount, an alert may be notified to the user by performing highlighting such as highlighting or blinking. Both FIG. 10 and FIGS. 11A and 11B may be displayed. When the user designates (for example, clicks) the component rectangle in FIG. 11A or FIG. 11B, detailed information on the corresponding component is displayed. The corresponding row in the table may be automatically highlighted.

(Advantages of this embodiment)
According to the configuration of the present embodiment described above, each component is based on the distribution of the exposure dose on the surface (surface on the radiation source side) of the inspection object and the distribution of the exposure dose on the back surface (surface opposite to the radiation source). Therefore, it is possible to calculate the exposure amount of the front side component and the exposure amount of the back side component with high accuracy. Moreover, since the absorption of X-rays by the printed circuit board and the absorption of X-rays by the components on the front surface are taken into account, the exposure dose of the components arranged on the back surface can be calculated with high accuracy. Therefore, the apparatus of the present embodiment can be particularly preferably applied to the exposure management of a double-sided mounting board having components mounted on both sides as well as a single-sided mounting board having components mounted on one side.

In this embodiment, the exposure amount map for each of the front and back surfaces of the inspection object, the exposure amount for each component, the determination result as to whether the exposure amount for each component is an allowable amount, and the like are output to the display device.
By providing such information to the user, it becomes easy to grasp and manage the exposure dose of each component by X-ray inspection.

Second Embodiment
With reference to FIG.12 and FIG.13, the X-ray inspection system which concerns on 2nd Embodiment of this invention is demonstrated. FIG. 12 is a diagram showing the configuration of the X-ray inspection system of the second embodiment, and FIG. 13 is a flowchart of the exposure dose calculation processing of the second embodiment. In the first embodiment described above, the exposure dose in one X-ray examination is calculated, whereas in the second embodiment, a history of X-ray examinations performed on the same examination object in the past is referred to. Thus, the cumulative exposure dose in a plurality of X-ray examinations is calculated. Only the configuration and processing unique to the second embodiment will be described below, and description of the same configuration and processing as in the first embodiment will be omitted.

  As shown in FIG. 12, the exposure dose management apparatus 11 of the present embodiment includes an examination history storage unit 115 and an exposure dose update unit 116 in addition to the functional configuration of the first embodiment. The inspection history storage unit 115 is a database that stores an inspection history for each inspection object (substrate in this embodiment). The inspection history is information relating to the history of X-ray inspections performed on the inspection target in the past. Any information may be used as long as it is information that can calculate the cumulative exposure dose of the inspection object. For example, the past number of examinations or the exposure dose received in the past examination can be used as the examination history. The exposure dose update unit 116 is a means for accumulating the exposure dose obtained by the X-ray examination performed in the past on the exposure dose calculated by the exposure dose calculation unit 111 based on the examination history.

  With reference to the flowchart of FIG. 13, the exposure amount calculation process of the present embodiment will be described. In the flowchart of FIG. 13, the same processing steps as those in the first embodiment (FIG. 6) are denoted by the same step numbers, and detailed description thereof is omitted.

  First, the data input unit 110 acquires data necessary for calculating the exposure dose (step S60). Next, the exposure dose calculation unit 111 calculates an exposure dose map on the surface of the substrate (surface on the radiation source side) based on the X-ray source information and X-ray irradiation conditions acquired in step S60 (step S61). Further, the exposure dose calculation unit 111 calculates an exposure dose map on the back surface (surface opposite to the radiation source) of the substrate based on the exposure dose map on the front surface calculated in step S61 and the target information (step S62). ). The processing so far is the same as in the first embodiment.

  Next, the exposure dose update unit 116 acquires the ID of the inspection object via the data input unit 110 (step S130). The ID (identification number) of the inspection object may be input by the user or recognized by reading a barcode, a two-dimensional code, an IC tag, or a number printed on the substrate. Alternatively, a notification may be received from an external device (for example, a host system that manages a production line).

  Next, the exposure dose update unit 116 acquires the inspection history corresponding to the ID of the inspection object from the inspection history storage unit 115 (step S131). In this embodiment, the inspection history is acquired from the inspection history storage unit 115 provided in the apparatus, but the inspection history may be acquired from an external database, an X-ray inspection apparatus, a host system, or the like.

Next, the exposure dose update unit 116 updates the exposure dose for each of the front and back surfaces calculated in steps S61 and S62 based on the inspection history of the inspection object (step S132). For example, when the past number of examinations is obtained as the examination history, the cumulative exposure amount is obtained by using the current exposure amount (the exposure amount calculated in steps S61 and S62) and the past examination number.

Cumulative dose = current dose x (number of past examinations + 1)

It can be calculated as follows. Alternatively, if the past exposure dose is obtained as the inspection history, the cumulative exposure dose is

Cumulative dose = Current dose + Past dose

It can be calculated as follows. In addition, the update method mentioned here is an example, and the accumulated exposure dose may be obtained by another calculation method.

  Through the above processing, cumulative exposure maps for the front and back surfaces are obtained. The subsequent processing (steps S63 to S67) is the same as that of the first embodiment except that the cumulative exposure dose map is used instead of the exposure dose map.

(Advantages of this embodiment)
According to the configuration of the present embodiment described above, in addition to the same advantages as those of the first embodiment, when the inspection target has undergone multiple X-ray inspections, There is an advantage that the cumulative exposure amount for each part can be grasped and managed.

<Other embodiments>
The configuration of the embodiment described above is merely a specific example of the present invention. The scope of the present invention is not limited to the above embodiment, and various modifications can be made within the scope of the technical idea.

  For example, in the above-described embodiment, an example of a double-sided mounting board is given as an inspection object, but the present invention can also be applied to an inspection of a group of components stacked on a component tray (tray inspection). In the above embodiment, an example in which X-rays are irradiated only on the upper surface has been described. However, the present invention can also be applied to an inspection in which X-rays are irradiated from both the upper and lower surfaces. In that case, the exposure dose calculation process described above may be performed for each of irradiation from the upper surface and irradiation from the lower surface, and these may be summed to calculate the cumulative exposure dose.

1: X-ray inspection system, 10: X-ray inspection apparatus, 11: X-ray exposure management apparatus, 12: Inspection object, 31-37: Parts, 100: X-ray source, 101: X-ray detector, 102: Stage , 103: control unit, 104: inspection unit, 105: storage unit, 110: data input unit, 111: exposure dose calculation unit, 112: determination unit, 113: information output unit, 114: display device, 115: inspection history storage Unit, 116: exposure dose update unit

Claims (23)

An exposure dose calculation unit for calculating an exposure dose to be received by the X-ray inspection of the inspection object;
In an exposure dose management apparatus having an information output unit that outputs information on the exposure dose of the inspection object,
The inspection object includes a plurality of parts,
The exposure dose calculation unit
Based on the positional relationship between the radiation source and the inspection object in the X-ray inspection, and the intensity of X-rays emitted from the radiation source, the first surface that is the radiation source side surface of the inspection object Calculate the exposure dose distribution on the surface ,
Subtract the X-ray absorption of the object existing between the radiation source and the individual parts of the plurality of parts from the exposure amount on the first surface, and the opposite side of the inspection object from the radiation source calculating a distribution of exposure amount in the second surface which is a surface,
An exposure dose management apparatus that calculates an exposure dose for each component based on a distribution of the exposure dose on each of the first surface and the second surface and an arrangement of each of the plurality of components. The inspection object includes a double-sided mounting board having a printed circuit board, a component disposed on the first surface of the printed circuit board, and a component disposed on the second surface of the printed circuit board. The exposure dose management apparatus according to claim 1. The exposure dose management apparatus according to claim 2, wherein the exposure dose calculation unit calculates an exposure dose distribution on the second surface in consideration of X-ray absorption by the printed circuit board. The exposure dose calculation unit calculates the distribution of the exposure dose on the second surface in consideration of X-ray absorption by components arranged on the first surface. Dose management device. When a plurality of times of X-ray irradiation are performed in one X-ray examination, the exposure dose calculation unit calculates the exposure dose due to each X-ray irradiation, and cumulatively adds them to obtain one X-ray exposure. The exposure dose management apparatus according to any one of claims 1 to 4, wherein a dose distribution by line inspection is calculated. 6. The method according to claim 1, further comprising: a determination unit that determines, for each component, whether the amount is within an allowable amount based on the exposure amount for each component calculated by the exposure amount calculation unit. The exposure dose management apparatus according to claim 1. An inspection history storage unit for storing a history of X-ray inspections performed on the inspection object in the past;
Based on the history, an exposure dose update unit that accumulates an exposure dose obtained by an X-ray examination performed in the past on the distribution of the exposure dose calculated by the exposure dose calculation unit and / or the exposure dose for each component; The exposure dose management apparatus according to any one of claims 1 to 6, further comprising: The said information output part outputs the exposure dose map which shows distribution of exposure dose to a display apparatus, The exposure dose management apparatus of any one of Claims 1-7 characterized by the above-mentioned. The said information output part outputs the information which shows the exposure amount for every component to a display apparatus, The exposure amount management apparatus of any one of Claims 1-8 characterized by the above-mentioned. The exposure information management according to any one of claims 1 to 9, wherein the information output unit outputs information indicating whether or not the exposure dose for each component is an allowable dose to the display device. apparatus. An X-ray inspection apparatus for performing an X-ray inspection of an inspection object;
The exposure management apparatus according to any one of claims 1 to 10, wherein the information on the exposure received by the X-ray inspection of the inspection object is output.
X-ray inspection system. An exposure dose calculating step for calculating an exposure dose received by the X-ray inspection of the inspection object;
An information output step for outputting information on the exposure dose of the inspection object, and an exposure dose management method comprising:
The inspection object includes a plurality of parts,
The exposure dose calculating step includes:
Based on the positional relationship between the radiation source and the inspection object in the X-ray inspection, and the intensity of X-rays emitted from the radiation source, the first surface that is the radiation source side surface of the inspection object Calculating a distribution of exposure on the surface;
Subtract the X-ray absorption of the object existing between the radiation source and the individual parts of the plurality of parts from the exposure amount on the first surface, and the opposite side of the inspection object from the radiation source calculating a distribution of exposure amount in the second surface which is a surface,
Calculating the exposure dose for each component based on the distribution of the exposure dose on each of the first surface and the second surface and the arrangement of each of the plurality of components. The inspection object includes a double-sided mounting board having a printed circuit board, a component disposed on the first surface of the printed circuit board, and a component disposed on the second surface of the printed circuit board.
The exposure dose management method according to claim 12. In the exposure dose calculating step, the distribution of the exposure dose on the second surface is calculated in consideration of X-ray absorption by the printed circuit board.
The exposure dose management method according to claim 13. In the exposure dose calculating step, the distribution of the exposure dose on the second surface is calculated in consideration of X-ray absorption by the components arranged on the first surface.
15. The exposure dose management method according to claim 13 or 14, When a plurality of X-ray irradiations are performed in one X-ray examination, in the exposure dose calculation step, the exposure doses of the respective X-ray irradiations are calculated and cumulatively added to calculate one exposure X Calculate the distribution of exposure by line inspection
The exposure dose management method according to any one of claims 12 to 15. Based on the exposure dose for each component calculated in the exposure dose calculation step, the method further includes a determination step for determining, for each component, whether or not it is within an allowable amount.
The exposure dose management method according to any one of claims 12 to 16. An inspection history storage step for storing a history of X-ray inspections performed on the inspection object in the past;
Based on the history, an exposure dose update step of accumulating the exposure dose calculated in the exposure dose distribution step and / or the exposure dose for each component to the exposure dose by the X-ray examination performed in the past, Further have
The exposure dose management method according to any one of claims 12 to 17, characterized in that: In the information output step, an exposure dose map showing a distribution of the exposure dose is output to the display device.
The exposure dose management method according to any one of claims 12 to 18, wherein the exposure dose is controlled. In the information output step, information indicating the exposure dose for each component is output to the display device.
The exposure dose management method according to any one of claims 12 to 19. In the information output step, information indicating whether the exposure dose for each component is an allowable dose is output to the display device.
21. The exposure dose management method according to any one of claims 12 to 20. An X-ray inspection method for performing an X-ray inspection of an inspection object;
The exposure dose management method according to any one of claims 12 to 21, wherein the information on the exposure dose received by the X-ray inspection of the inspection object is output.
X-ray inspection system to perform. The program for making a computer perform each step of the exposure management method of any one of Claims 12-21 .

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