JP2012145484A - Solder inspection method, solder inspection machine, and board inspection system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a solder inspection method, a solder inspection machine, and a board inspection system that highly accurately estimate the characteristics of a portion whose condition is hard to determine via images shot during a solder printing inspection, and enhance the inspection accuracy of the solder condition by means of a determination process that takes into account the result of the estimation.SOLUTION: A solder printing inspection machine 10 inspects a cream solder on a land of a board by measuring the volume of the cream solder, and sends information on the inspection result containing a measurement value to an inspection data management device 102. A solder inspection machine 30 detects characteristic data of a soldered portion to be inspected from images of the board as of after a reflow and, through communication with the inspection data management device 102, obtains the volume of the cream solder that has been gained by the measurement of a portion corresponding to the soldered portion to be inspected conducted by the solder printing inspection machine 10. Then, using the obtained volume, the solder inspection machine estimates the characteristics of a portion in the proximity of a part, whose characteristics data are hard to measure, calculates the height of a wet solder as of after the reflow by supplementing the characteristic data with the result of the estimation, and determines whether the height is proper or not.

Description

  The present invention confirms the suitability of the soldering state of various components mounted on the board by visual inspection for the board that has been completed up to the reflow process among a plurality of processes carried out for the production of the component mounting board. The present invention relates to a determination method, and a soldering inspection machine and an inspection system to which the method is applied.

  The component mounting board is generally produced by a cream solder printing process, a component mounting process, and a reflow process. In recent production lines, a board inspection system has been introduced in which inspection machines are provided for each of these processes, and inspection results from each inspection machine are accumulated in an information processing device so that they can be checked against each other. (For example, refer to Patent Document 1).

  Regarding the inspection of the soldered part after the reflow process, using the specular reflectivity of the solder, the substrate to be inspected is illuminated from diagonally above, and the substrate is imaged from directly above, and the reflection in the generated image is reflected. Inspection machines that analyze optical image patterns are widely used. For example, in Patent Document 2, by irradiating a substrate with red, green, and blue color lights from different directions of incident angles, the state of solder inclination is determined by a color distribution pattern corresponding to these illumination lights. Is generated, and the suitability of the shape of the solder fillet is determined based on the color distribution pattern.

  Further, in Patent Document 3, in the soldering inspection machine described in Patent Document 2, it is difficult to guide reflected light from a location where the inclination is steep in the vicinity of the part in the image or a location near the flat to the camera. An improved invention focusing on this point is described. Specifically, in the invention described in Patent Document 3, in addition to the illumination light of each color, the substrate is irradiated with infrared light from the direction along the optical axis of the camera, and an image including a reflected light image with respect to this infrared light Is generated. In the inspection area corresponding to the soldered part in the image, the color area corresponding to each color light and the area corresponding to the infrared light (infrared area) are extracted and reflected to any illumination light at a position near the part. A portion that is a dark region because no optical image is generated is extracted. Then, by extracting the boundary positions between the areas along the direction in which the areas are arranged and applying the boundary angles of the inclination angle range represented by the area corresponding to each illumination light to these boundary positions, the inclination state of the fillet The approximate curve that represents is specified. Further, by integrating this approximate curve, the wetting height of the solder is obtained, and the suitability of this height is determined.

  In the inspection after the solder printing process, similarly, an inspection machine that measures the area of the solder paste, the printing position, etc. in each land on the board by imaging the board from directly above and performing two-dimensional image processing. Is used. There is also an inspection machine that obtains a three-dimensional shape and volume of a region to be inspected by a phase shift method (see, for example, Patent Document 4).

Japanese Patent No. 3966336 Japanese Patent No. 3599023 JP 2010-71844 A JP 2010-91569 A

  The conventional inspection after the reflow process is performed on the assumption that appropriate processing is performed in each process before the reflow process. However, in actuality, there are variations and changes with time in the printing amount and printing position of cream solder, the mounting position of components, etc. in the solder printing process, and the tilted state of the fillet fluctuates due to the variations and changes.

  Hereinafter, the above problem will be described with reference to FIGS. Each figure is a schematic diagram showing that the shape of the solder fillet after the reflow process with respect to the electrode on one side of the chip component 301 varies depending on the state before the reflow process. In each figure, 300 is a land, 301 is a component body, and 302 is a component electrode corresponding to the land 300 (the component electrode on the side not corresponding to the land 300 is not shown). Reference numeral 303 denotes cream solder before reflow, and 304 denotes solder solidified after melting in the reflow process (hereinafter referred to as “post-reflow solder”).

  FIG. 10 shows the relationship between the amount of cream solder 304 printed on the land 300 in the solder printing process and the fillet of the solder after reflow. As shown in FIG. 10, generally, as the amount of cream solder 303 increases, the inclination of the fillet of the post-reflow solder 304 becomes steep, and as the amount of cream solder 303 decreases, the inclination of the fillet of the post-reflow solder 304 gradually decreases. Become.

  Next, FIG. 11 shows the influence of the mounting position of the component 301 on the shape of the solder 304 after reflow. In the three examples shown in this figure, the printing amount of the cream solder 303 is the same, but since the position of the component 301 with respect to the land 300 is different, the portion from the electrode 302 of the component 301 to the outer edge of the land 300 ( Hereinafter, this portion is referred to as “land protruding portion”). As shown in each example, generally, the slope of the fillet of the solder 304 after reflow becomes steeper as the width of the land protrusion becomes narrower, and the inclination of the fillet of the solder 304 after reflow becomes gentler as the width of the land protrusion becomes wider. .

  Next, FIGS. 12 and 13 show the influence of the difference in the printing range of the cream solder 303 on the land 300 on the shape of the fillet. In the example shown in FIG. 12, the volume of the cream solder 303 is the same. However, in the upper example, the cream solder 303 is spread over the entire land 300 and printed, and the amount of the cream solder 303 corresponding to the land protruding portion is increased. Since it is relatively less, a relatively loose fillet is formed. On the other hand, since the cream solder 303 in the lower example is printed in a biased position at the land protruding portion, the inclination of the formed fillet is steeper than in the above example.

  In the example of FIG. 13, the volume of the cream solder 303 is the same, but in the upper example, since the cream solder 303 is spread and printed over almost the entire land 300, the volume is relatively moderate as in the upper example of FIG. 12. A perfect fillet is formed. On the other hand, the cream solder 303 in the lower example is printed in a biased manner in the center of the land 300, and the amount of solder in the land protruding portion and the solder under the component electrode 302 is not changed so much. 301 is also arranged at a higher position than the upper example. As a result, in the reflow process, a phenomenon in which the solder flows into the space between the component 301 and the land 300 occurs, and a part of the solder melted at the land protruding portion is drawn below the component electrode 302. Also, the solder remaining in the solder protruding portion is pulled toward the component 301 to form a short and steep fillet.

  As shown in each of the above examples, the shape of the fillet of the post-reflow solder 304 varies greatly depending on the printing state of the cream solder 303 and the state of the component 301. However, in general visual inspection, the soldering site is illuminated obliquely from above, and the reflected light from the soldering site that enters the camera installed so that the surface of the board is viewed in front is imaged for inspection. In order to generate an image, it is difficult to obtain a reflected light image of a steep solder near the part. For this reason, there exists a possibility that the shape of the fillet of a soldering site | part cannot be recognized correctly.

  Further, as in the example in the lower part of FIG. 11 and the example in the lower part of FIG. 13, the fillet width is short and steep even when there is no particular problem in the connection between the component electrode 302 and the land 300 via the solder 304 after reflow. In such a case, most of the fillets appear in the image as dark areas where no reflected light image is generated, so there is a possibility that the conventional inspection standard may determine that the fillet is defective.

  The present invention pays attention to the above-mentioned problem, accurately estimates the characteristics of a portion where it is difficult to determine the state in the image of the substrate after the reflow process, and determines the soldering state by reflecting this estimation result. It is an object to improve the accuracy of the attached state inspection.

In the present invention, a camera is arranged toward the surface of the board that has been subjected to the reflow process among a plurality of processes performed for the production of the component mounting board, and an image of the board generated by the camera is used. This method is applied to a method for inspecting the soldering state of components on the board.
In the inspection method according to the present invention, on the premise that the configuration added to the substrate in at least one of the plurality of steps performed before the reflow step is measured before the next step is started, Regarding the features of the soldered parts that are difficult to determine in the camera image, the causal relationship between the measured values obtained for the parts corresponding to the soldered parts in the measurement process prior to the reflow process is specified in advance. Thus, the causal relationship information indicating the relationship is registered. And the following 1st-4th steps are performed with respect to the soldering site | part used as the object of the inspection after a reflow process.

In the first step, feature data representing the shape of the solder is acquired by processing a range including the soldered portion to be inspected in the image.
In the second step, the measurement value obtained in the measurement process prior to the reflow process for the location corresponding to the soldering site is acquired.
In the third step, using the causal relationship information registered with respect to the soldering part and the measurement value acquired in the second step, the characteristics of a part of the soldering part that is difficult to determine in the image are estimated. .
In the fourth step, the feature data acquired in the first step is supplemented with the estimation result in the third step, and the quality of the soldered part is determined.

  According to the above method, among the soldered parts to be inspected, the reflected light image with respect to the illumination light could not be generated, so the part that became a dark area in the image or the part that was hidden by the part and could not be recognized was targeted. By registering the causal relationship information and applying the third step to these locations, the characteristics can be estimated. Therefore, in the fourth step, by complementing the result of the above estimation processing to the feature data acquired by the image processing, it is possible to increase the recognition accuracy of the shape of the soldered part, and the accuracy of the inspection is also increased.

  In addition, causal relationship information is created by identifying the relationship between the state of the target part of the measurement process prior to the reflow process and the state of the soldered part to be inspected by statistical processing using a considerable number of samples. Can do. The greater the number of samples, the higher the reliability of the causal information, and the accuracy of estimation in the third step can be increased. The causal relationship information is, for example, a table associating measurement values obtained by measurement processing prior to the reflow process and data indicating the characteristics of the part to be estimated in the third step, or the relationship between the two. Registered as a function to represent. When measurement values of a plurality of parameters are used, a program that defines rules for deriving feature data from combinations of these measurement values may be registered as causal relationship information.

  In a preferred embodiment of the above inspection method, measurement is performed on cream solder printed on each land of the substrate in the solder printing process as the measurement process in the process before the reflow process. According to this embodiment, even when there is a difference in the shape of the solder after reflow depending on the printing amount or printing position of the cream solder, the characteristics of the location where it is difficult to determine the state in the image are estimated with high accuracy, and the soldering site It becomes possible to judge good / bad.

  In another preferred embodiment of the above inspection method, as the measurement process in the process prior to the reflow process, the measurement process for the cream solder printed on each land of the board in the solder printing process and the mounting on the board in the component mounting process. Assuming that measurement processing is performed on the parts, the causal relationship between the combination of the measurement values obtained by these measurement processing and the features of the soldered parts to be inspected that are difficult to determine in the camera image The causal relationship information shown is registered.

  According to this embodiment, it is possible to accurately estimate the feature of a location where it is difficult to determine the state on the image based on the mounting state of the component in addition to the cream solder printing state. For example, even if the measured value of the volume of cream solder is the same, the estimation results can be different if the position, size, height, etc. of the parts are different.

  As the measurement process for cream solder printed on the land of the substrate, for example, at least one of the volume, area, height, print position, and print range of the cream solder can be measured. Moreover, as a measurement process for the component mounted on the board, for example, at least one of the position, size, positional relationship with the land, and height of the component can be measured (measurement of the size of the component). (This is because parts with the same function may vary in size from manufacturer to manufacturer.)

In another preferred embodiment of the inspection method described above, in the first step, in the vicinity of the part of the soldered part in the image, a portion where the feature data should be acquired but cannot be acquired is extracted. Region features are estimated in a third step.
According to this embodiment, by estimating the feature of a part that is in the vicinity of the part and does not appear in the image due to the steep inclination, and complementing this estimation result, The shape of the fillet can be accurately recognized.

  Next, the soldering inspection machine according to the present invention is arranged toward the surface of the board, targeting the board that has finished up to the reflow process among a plurality of processes carried out for the production of the component mounting board. The substrate is imaged by a camera, and the soldering state of a component in the generated image is inspected, and includes the following storage means, image processing means, measurement value input means, estimation means, and determination means.

  The storage means uses a camera among the soldered parts to be inspected on the premise that the configuration added to the substrate in at least one of the processes before the reflow process is measured before the next process is started. Set the feature of the location where it is difficult to determine the state in the image based on the result of processing to identify the causal relationship with the measurement value obtained for the location corresponding to the soldered part in the measurement process before the reflow process The causal relationship information thus registered is registered.

The image processing means processes a range including the soldered portion to be inspected in the image, and acquires feature data representing the shape of the solder. The measured value input means inputs the measured value obtained by the measurement process prior to the reflow process for the location corresponding to the soldering site to be inspected.
The estimation means uses the causal relationship information registered in the storage means for the part to be inspected and the measurement value input by the measurement value input means for the soldering part to be inspected, and the state of the soldering part in the image is indicated. Estimate the features of the parts that are difficult to distinguish.
The determining means complements the estimation result by the estimating means to the feature data acquired by the image processing means to determine whether the soldered part is good or bad.

  According to said structure, it becomes possible to perform a test | inspection with a sufficient precision by performing the above-mentioned test | inspection method. In addition, the measured value by the measurement process before the reflow process is acquired by communication with, for example, an inspection machine installed in the process before the reflow process or an information processing apparatus that holds inspection result information output from the inspection machine. be able to.

  A soldering inspection machine according to an embodiment of the present invention operates a lighting device that irradiates light from a plurality of directions with different incident angles on a substrate to be inspected, and operates the camera under illumination by the lighting device. In this way, it further comprises imaging control means for generating an image for inspection.

Further, in this embodiment, the storage means is a dark region because a reflected light image due to light from the illuminating device cannot be obtained in the image in the vicinity of the component among the soldered parts to be inspected. The causal relationship information indicating the causal relationship between the inclination angle of the location and the measurement value obtained by the measurement process for the cream solder printed on the land in the solder printing process is registered. The image processing means extracts the region where the reflected light image corresponding to the illumination light appears from the range including the soldered part to be inspected in the image for each direction of the illumination light, and is generated in the vicinity of the component in the image. The dark area that is present is extracted. The estimation means estimates the inclination angle of the location corresponding to the dark region using the causal relationship information registered in the storage means regarding the soldered part to be inspected and the measurement value input by the measurement value input means. The determination means complements the inclination angle estimated by the estimation means in the dark region, and calculates the inclination angle of the solder calculated from the incident angle of the illumination light corresponding to the reflected light image corresponding to the illumination light from each direction. Apply and determine the suitability of the fillet wetting of the soldering site using these inclination angles.
Note that the illumination device is configured to irradiate a plurality of color lights simultaneously from directions having different incident angles, for example. Or it can also comprise so that light from each direction may be switched in order and irradiated.

  According to the above-described embodiment, illumination light is incident under illumination with light from a plurality of directions with different incident angles, and illumination light corresponding to each reflected light image generated at a soldered portion in the generated image is incident. When recognizing the shape of a solder fillet by applying an inclination angle calculated from the angle, even if there is a dark area without any reflected light image in the vicinity of the part in the image, The tilt angle can be estimated with high accuracy. Therefore, by complementing the estimated inclination angle, it is possible to recognize almost the entire shape of the fillet at the soldering site and accurately determine the wetting height.

  A solder printing inspection machine according to another embodiment of the present invention includes a projection device for projecting a striped pattern image onto a substrate to be inspected, and the pattern image is arranged along the stripes on the projection device. The image forming apparatus further includes imaging control means for projecting while periodically moving and operating the camera in accordance with the timing of each projection.

Furthermore, in this embodiment, the storage means prints on the lands in the solder printing process, the height of a portion of the soldered portion to be inspected that is in the vicinity of the part and where the reflected light image of the pattern image cannot be obtained. The causal relationship information indicating the causal relationship with the measurement value obtained by the measurement process for the cream solder that has been performed is registered. The image processing means uses a plurality of images generated by imaging while projection for one cycle of the pattern image is performed, and projects for one cycle for each pixel within the range including the soldered part to be inspected. The height corresponding to the pixel is measured based on the phase of the brightness change that occurred in the pixel during the period. Further, a pixel group representing the height of the solder fillet is extracted based on the measurement result, and a pixel group whose height could not be measured because a change in brightness was not obtained at a position near the component is extracted. The estimation means estimates the height of the pixel group whose height could not be measured using the causal relationship information registered in the storage means with respect to the soldered part to be inspected and the measurement value input by the measurement value input means. To do.
The determination means complements the height estimated by the estimation means to the pixel group whose height could not be measured, and uses the height values in the pixel group representing the height of the pixel group and the solder fillet. The suitability of the wetted fillet at the attachment site is determined.

  The solder printing machine of the above embodiment, based on the phase shift method, projects a striped pattern image on the surface of the soldering site while moving the pattern every time, and performs imaging in accordance with the hourly projection, Height data at each point of the fillet is obtained from the phase of change in brightness in pixel units. With respect to a portion of the fillet where the inclination near the part is steep, it is difficult to generate a reflected light image of the pattern image projected on the portion, so there is a possibility that the height cannot be measured. According to the above, it is possible to estimate the height of the location where the height could not be measured using the measurement value obtained by the measurement process before the reflow process. Therefore, by complementing this estimation result, it is possible to obtain the height data of the entire fillet at the soldering site and accurately determine the wet state of the fillet.

The system according to the present invention includes an inspection machine that is arranged in a reflow process among a plurality of processes performed for production of a component mounting board and inspects a substrate after the reflow process, and at least one process before the reflow process. An inspection machine that is deployed and inspects the substrate after the process, and information management that imports inspection result information from each inspection machine by communication and manages the inspection result information for each inspection machine so that it can be read out by board and by inspection target part Device.
The inspection machine in the reflow process processes a range including a camera arranged toward the surface of the substrate to be inspected and a soldered portion to be inspected in an image generated by the camera to represent the shape of the solder. Image processing means for acquiring feature data.

The information management device corresponds to the soldering part of the inspection machine in the process prior to the reflow process with respect to the characteristics of the soldering part of the inspection target of the reflow process inspection machine that is difficult to determine the state by the camera image. Storage means for registering causal relationship information set based on the result of performing the process of specifying the causal relationship with the measurement value obtained by the measurement process for the location; from the reflow process for the location corresponding to the soldering site to be inspected Measurement value input means for inputting a measurement value obtained by measurement processing by an inspection machine in the previous process; causal relation information and measurement value input means registered in the storage means for the soldered part to be inspected An estimation means for estimating the characteristics of a portion of the soldered portion where it is difficult to determine the state using an input measurement value; and Comprising the means of the transmitting means for transmitting the estimation result by the estimating means to the inspection machine reflow process.
The inspection machine in the reflow process further includes a determination unit that complements the estimation result transmitted from the information management device to the feature data acquired by the image processing unit and determines whether the soldered portion is good or defective.

  According to the system having the above-described configuration, the result of the measurement performed by the inspection machine prior to the reflow process on the soldered part to be inspected in the soldering part to be inspected that is difficult to determine the state from the image. Since the information management apparatus shares the processing that is estimated based on the above, it is possible to reduce the calculation burden of the soldering inspection machine and perform high-precision inspection. In addition, since the estimation process in the information management apparatus can be performed before the inspection with the soldering inspection machine is started, the time required for the soldering inspection can be shortened.

  According to the present invention, among the soldered parts to be inspected, the characteristics of a part where it is difficult to determine the state in the image are estimated based on the state of the cream solder and the part state before the reflow process, and acquired by image processing. Since the feature data estimated by the above estimation process is complemented to the feature data to determine whether the soldered portion is good or bad, the accuracy of the inspection on the soldered portion can be improved.

It is a figure which shows the structure of a board | substrate inspection system corresponding to the whole structure of the production line of a component mounting board | substrate. It is a block diagram which shows the structure of a soldering inspection machine. It is a block diagram which shows the structure of a solder printing inspection machine. It is a figure which shows the flow of the information between the apparatuses in connection with a soldering test | inspection. It is a figure which shows typically the structure of the table for estimation as an example, and the figure which shows the relationship of each group in a table. It is a figure explaining the method to measure the wetting height of the solder after reflow. It is a flowchart which shows the procedure of the test | inspection in a soldering inspection machine. It is a flowchart which shows the procedure of the test | inspection in the case of decompress | restoring the three-dimensional shape of a soldering site | part based on a phase shift method. It is a figure which shows the flow of the information between each apparatus in the case of performing an estimation process in a test | inspection data management apparatus. It is a figure which shows the influence which the difference in the quantity of cream solder has on the shape of a fillet. It is a figure which shows the influence which the difference in the width | variety of the protrusion part of the land accompanying the mounting position of components has on the shape of a fillet. It is a figure which shows the influence which the printing bias of cream solder exerts on the shape of a fillet. It is a figure which shows the influence which the printing bias of cream solder exerts on the shape of a fillet.

FIG. 1 shows the configuration of an embodiment of a board inspection system in association with the overall configuration of a production line for component-mounted boards.
The illustrated production line includes a solder printing process, a component mounting process, and a reflow process. In the solder printing process, a solder printing apparatus 11 for applying cream solder to each land on the substrate and a solder printing inspection machine 10 for inspecting a processing result by the apparatus 11 are provided. In the component mounting process, a mounter 21 that mounts components on a board after solder printing and a component inspection machine 20 that inspects the mounting state of the components are provided. In the reflow process, a reflow furnace 31 for melting the cream solder on the substrate after mounting the components and a soldering inspection machine 30 for inspecting the substrate after reflow are provided. The substrate is sent to each device in order along the flow indicated by the thick arrow in the drawing and processed, thereby completing a component mounting substrate according to a predetermined standard.

  The inspection machines 10, 20, and 30 in each process are connected to each other via the LAN line 100. An inspection program management apparatus 101 and an inspection data management apparatus 102 are further connected to the LAN line 100. In the inspection program management apparatus 101, a database in which an inspection program for executing an inspection based on a predetermined inspection standard is collected as library data for each part type is registered for each of the inspection machines 10, 20, and 30. Yes.

  In the inspection data management apparatus 102, inspection result information transmitted from each inspection machine 10, 20, 30 is stored. This inspection result information includes a determination result of pass / fail for each inspection target part and a measurement result performed for the determination. The inspection result information is configured to be able to be read for each inspection machine 10, 20, 30 and for each board and for each individual component on the board. For example, with the identification code of the inspection machine as the highest level, it is possible to assemble the information as a hierarchical structure in the order of the identification code of the board, the identification code of the mounted component, and the identification code of the inspection area.

  Note that the inspection program management apparatus 101 and the inspection data management apparatus 102 are not necessarily separate from each other, and the functions of the management apparatuses 101 and 102 may be provided in one computer. On the contrary, it is possible to configure each management apparatus 101, 102 by a plurality of computers.

  Prior to the inspection, the inspection machines 10, 20, and 30 input data (for example, CAD data) indicating the configuration of the inspection target board, and inspect library data suitable for the component type information of each component indicated by the input data. A process of fetching from the program management apparatus 101 and associating the position information of each component with the library data is performed. As a result, an environment necessary for the inspection of the inspection target substrate is set in each of the inspection machines 10, 20, and 30. Note that the contents of the program based on the library data can be appropriately changed according to the setting operation by the user.

FIG. 2 shows the configuration of the soldering inspection machine 30.
The soldering inspection machine 30 of this embodiment includes a control processing unit 1, a camera 2, an illumination device 3, a substrate stage 4, and the like. The substrate stage 4 moves the substrate S in the direction along each side while supporting the substrate S to be inspected in a horizontal posture. The camera 2 generates a color image, and is disposed above the substrate stage 4 in a state where the optical axis is oriented in a substantially vertical direction (a state where the substrate S on the stage 4 is viewed from the front). The illumination device 3 is arranged between the camera 2 and the substrate stage 4.

  The illumination device 3 includes annular light sources 3R, 3G, and 3B that emit red light, green light, and blue light, respectively. Each of the light sources 3R, 3G, 3B is arranged in a state in which each central portion is aligned with the optical axis of the camera 2. The light sources 3R, 3G, and 3B have different diameters, the red light source 3R having the smallest diameter is disposed at the top, and the blue light source 3B having the largest diameter is disposed at the bottom. A green light source 3G is disposed between them. With this arrangement, the range of the incident angle with respect to the substrate S is different for each color, and the camera 2 represents the inclined state of the inclined surface of the solder after reflow by the distribution pattern of the three colors corresponding to each color light. Image can be generated. Specifically, the red region caused by red light with the smallest incident angle range among the three colors shows a gentle slope, and the blue region caused by blue light with the largest incident angle among the three colors shows a fairly steep slope. Indicates. Moreover, the green area | region produced by the green light irradiated from the range between red light and blue light shows the angle range between the angle ranges which a red area | region and a blue area show.

  The control processing unit 1 includes a computer control unit 110, an image input unit 111, an imaging control unit 112, an illumination control unit 113, a stage control unit 114, a memory 115, a hard disk device 116, a communication interface 117, an input unit 118, a display. Part 119 and the like are included. The control unit 110 controls operations of the camera 2, the illumination device 3, and the substrate stage 4 via the imaging control unit 112, the illumination control unit 113, and the stage control unit 114. An image generated by the camera 2 is digitally converted by the image input unit 111 and then input to the control unit 110.

  The memory 115 stores programs related to the above control, and temporarily stores image data to be processed, calculation results, and the like. The hard disk device 116 stores an inspection program group based on the library data provided from the inspection program management device 101, measurement data and inspection results obtained during the inspection process, images used for the inspection, and the like.

  The communication interface 117 is for communicating with other devices via the LAN line 100 described above. The input unit 118 is used for an operation for designating the start and end of inspection and for inputting various setting data. The display unit 119 is for displaying an inspection result and an image used for the inspection.

Next, FIG. 3 shows a configuration of the solder printing inspection machine 10. In FIG. 3, the configuration corresponding to FIG. 2 is indicated by the same reference numerals as those in FIG.
This solder printing inspection machine 10 measures the height of cream solder printed on the land of the substrate S based on the principle of the phase shift method, and controls the control processing unit 1A, camera 2A, illumination device 3A, and substrate stage 4A. In addition, it has a projector 5 for projecting a striped pattern image onto the substrate. In addition, the illumination device 3A of the inspection machine 10 includes an annular light source 3M that emits white light. In addition to the same configuration as the control processing unit 1 of the soldering inspection machine 30, the control processing unit 1A is provided with a projector control unit 120.

Since the component inspection machine 20 has substantially the same configuration as the soldering inspection machine 30, illustration thereof is omitted. However, in the component inspection machine 10, the light source of the illumination device 3 may be a white light source.
The component inspection machine 20 detects a component on the substrate from the image of the substrate S to be inspected, measures its position, inclination, and the like, and determines whether the mounting state of the component is appropriate based on the measurement result.

  Further, as the component inspection machine 20, an apparatus having the same configuration as that of the solder printing inspection machine 10 shown in FIG. 3 can be used. In this case, in addition to the inspection of the mounting position and orientation of the component, it is possible to inspect the height of the component and the component electrode, the inclination of the component with respect to the vertical direction, and the like.

  Of the above three types of inspection machines 10, 20, and 30, the solder printing inspection machine 10 and the parts inspection machine 20 perform inspections in an intermediate process. In some cases, the quality may be improved by this process. Therefore, in many sites, it is allowed to flow the board determined to be defective by the solder printing inspection machine 10 or the parts inspection machine 20 to the subsequent stage without removing it from the line.

  On the other hand, in the soldering inspection machine 30 placed in the final reflow process, it is necessary to make a strict determination so as not to miss a defect. However, according to the configuration of the optical system of the soldering inspection machine 30 shown in FIG. 2, an inclined surface steeper than the inclination angle range represented by blue light having the largest incident angle is a reflected light image indicating the inclination angle. Therefore, it is difficult to recognize the entire shape of the solder fillet after reflow. Especially in parts where the dark area in the vicinity of the parts is large, or parts where the color distribution is hardly generated in the soldering part because the fillet is short and the inclination is steep, even if the actual soldering state is good, In the determination based only on the result of the image processing, it is necessary to determine that it is defective.

  Therefore, in this embodiment, when the inspection is performed by the soldering inspection machine 30, the result of the measurement processing performed by the other inspection machines 10 and 20 is read with respect to the part corresponding to the soldering part to be inspected. The inclination angle of the dark region of the soldering site is estimated based on the measured value. For this estimation process, an estimation table derived in advance using a considerable number of samples for each component type is registered in the memory 115 or the hard disk device 116 of the solder printing inspection machine 30. This estimation table is included in the library data for each part type described above, and is provided from the inspection program management apparatus 101.

  FIG. 4 shows an example of the case where the above estimation process is performed using the measurement result obtained by the solder printing inspection machine 10, and shows the relationship between the devices related to the soldering inspection together with the information flow. In this example, in addition to the soldering inspection machine 30 and the solder printing inspection machine 10, the inspection program management device 101 and the inspection data management device 102 are involved in the soldering inspection.

  The inspection program management apparatus 101 provides each inspection machine 10, 30 with an inspection program corresponding to each model. These programs are created for each part type based on the inspection criteria for parts belonging to that part type, and are registered in the inspection program management apparatus 101 as library data. Specifically, in this example, the solder printing inspection machine 10 is provided with an inspection program for inspecting the volume of cream solder printed on the land ((a) of FIG. 4). Is provided with a program for inspecting the solder wetting height after reflow of the soldering part (FIG. 4B). Further, the soldering inspection machine 30 is provided with an estimation table used in an estimation process when measuring the wetting height (FIG. 4C).

  The solder printing inspection machine 10 measures the volume of the cream solder printed on each land of the board S to be inspected based on the provided inspection program, and determines whether the measured value is good or bad. Then, the inspection result information including the measurement value for each land is transmitted to the inspection data management apparatus 102 ((d) in FIG. 4). The inspection data management apparatus 102 accumulates the inspection result information in a format that can be read out for each board and each component.

  The soldering inspection machine 30 also measures the wetting height of the solder after reflow in each land of the board S to be inspected based on the provided inspection program, determines whether the measured value is good or bad, and determines the measured value. The included inspection result information is transmitted to the inspection data management apparatus 102 ((e) in FIG. 4). However, in the measurement process of the soldering inspection machine 30, red, green, and blue color regions and components are detected from the image to be processed, and a dark region located in the vicinity of the component is detected, and this dark region is dealt with. Estimate the inclination angle of the location. Then, the estimation result is complemented to the dark region, and an inclination angle calculated from the incident angle of the corresponding color light is applied to each color region, and the distribution state of each region including the dark region and each region are corresponded. Measure the solder wetting height after reflow from the relationship with the tilt angle.

  In the estimation process for the dark region, the volume of the cream solder obtained when the solder print inspection machine 10 inspects the land corresponding to the soldering site during the processing of the substrate S to be inspected by accessing the inspection data management device 102. Is read ((f) of FIG. 4). Further, the width of the land protruding portion (the distance from the edge of the component to the outer edge of the land; hereinafter referred to as “land protruding width”) is obtained based on the detection result of the part or land by the own device. The inclination angle of the portion corresponding to the dark region is estimated by comparing the estimation table with the land protrusion width and the cream solder volume obtained from the inspection data management device 102.

  FIG. 5 (1) is a schematic diagram showing a configuration of an estimation table registered in the soldering inspection machine 30. This estimation table is created by statistical processing using a considerable number of samples for each component type, and stored in the library data together with the inspection program. In the estimation table in the example of FIG. 5A, for the fillet in which the inclined surface in the vicinity of the part is steeper than the angle range corresponding to the blue region, the inclination angle in the vicinity of each part is set to five groups g1 to g1. The distribution of combinations of values of the volume of cream solder and the land protrusion width in the samples belonging to the group is shown for each group g1 to g5. In other words, by referring to this estimation table by the combination of each value of the cream solder volume and the land protrusion width, which of the groups g1 to g5 includes the inclination angle near the part of the fillet caused by this combination? Can know.

  As shown in FIG. 5 (2), each of the groups g1 to g5 includes an angle range having a predetermined width, and the angle belonging to the group g1 is the largest. Hereinafter, the groups g2, g3, g4, and g5 are sequentially ordered. The angle becomes smaller.

  The sample used for creating the estimation table is based on data obtained from a real substrate, but is not limited to this. For example, it is possible to obtain a large number of samples by obtaining a fillet shape obtained from cream solder having various volumes by a fluid simulation method and measuring an inclination angle in a range that can be a dark region in the image of the fillet.

Hereinafter, the specific contents of the inspection performed in each inspection machine 10 and 30 by the inspection program shown in FIG. 4 will be described.
First, regarding the inspection in the solder printing inspection machine 10, the solder printing inspection machine 10 calculates the volume of cream solder by a process based on three-dimensional measurement based on the principle of the phase shift method. In the three-dimensional measurement, a process of projecting a striped pattern image from the projector 5 onto the substrate S while moving the stripes by a predetermined amount is performed as a plurality of projections as one cycle, and in accordance with the timing of each projection. Imaging is performed by the camera 2A. When projection and imaging for one cycle are completed, a change in luminance in each imaging is performed for each pixel in the inspection area (set for each land) in the image obtained by each imaging. The phase of the sine wave is obtained by detecting this change as a sine wave for one period. Further, by applying triangulation based on the phase calculated for the pixel to be processed, the projection surface of the pattern image, and the relationship between the camera 2A and a predetermined reference surface (for example, a height corresponding to the substrate), The distance from the surface to the point corresponding to the pixel to be processed is calculated. This distance indicates the height of the point corresponding to the pixel to be processed.

  In addition to the above processing, the solder printing inspection machine 10 performs imaging under white illumination of the illumination unit 3 and detects the color of the cream solder from the inspection region in the generated image. Then, the volume of the cream solder is obtained by integrating the height data calculated for the pixel in which the color of the solder is detected.

  When the volume of the cream solder is calculated by the above method, the solder printing inspection machine 10 compares the volume with the standard value registered for each inspection area, thereby determining “appropriate”, “oversolder”, “undersolder” Into one of three groups. However, the board on which the cream solder determined to be “excessive solder” or “excessive solder” is also passed to the subsequent process.

Next, measurement processing for inspection in the soldering inspection machine 30 will be described.
In the soldering inspection machine 30 of this embodiment, each of the red, green, and blue color lights is applied to the substrate S from different directions of incident angles. With the light incident on the camera 2 out of the reflected light, an image can be generated in which the tilted state of the solder after reflow is represented by a distribution pattern of each color of red, green, and blue. Each color region in the image expresses an inclination angle substantially the same as the incident angle of the corresponding illumination light. In this embodiment, the wetting height of the solder after reflow is measured by the method shown in FIG. 6 using the relationship between each color area and the inclination angle range and the inclination angle estimated for the dark area. In this embodiment, the inclination angle range indicated by the red region is 8 to 15 degrees, the inclination angle range indicated by the green region is 15 to 25 degrees, and the inclination angle range indicated by the blue region is 25 to 38 degrees.

  In FIG. 6, taking the chip component 200 as an example, a schematic diagram showing a reflow solder fillet 202 that connects the electrode 201 and the land 203 of the chip component 200, and a schematic diagram of an image obtained by imaging the fillet 202 Are associated with each other vertically. In the schematic diagram of the image, each color region is indicated by a different paint pattern.

  In this embodiment, a part inspection area (not shown) is set in a range including the whole part 200 in the image to detect the part 200, and an inspection area F is set for each land 203. A red area, a green area, and a blue area in the inspection area F are detected. In a fillet image having a shape as shown in FIG. 6, colors are generally distributed in the order of red, green, and blue along the direction from the location near the outer edge of the land 202 to the component electrode 201 in the image. In addition, a dark region representing a steeply inclined surface exceeding the range that can be represented by the blue region may occur near the component 200.

  In this embodiment, by utilizing the characteristics of the above image, a direction in which four color regions including a dark region are distributed in the inspection region F is found, and a measurement line L is set along this direction. In the line L, the points A2, A3, A4 located at the boundary of each color region and the intersection A1 with the outer edge of the red region are extracted. Further, based on the detection result of the component, an intersection A5 (end point of the dark region) between the measurement line L and the edge of the component electrode 201 is extracted.

  Of the extracted points, an inclination angle corresponding to the point is assigned to each point excluding the point A5. The inclination angle indicated by each color area has a certain width, but the boundary position between adjacent color areas is considered to indicate an angle near the boundary value of the inclination angle range indicated by each color area. Therefore, in this embodiment, 8 degrees is applied to the point A1, 15 degrees to the point A2, 25 degrees to the point A3, and 38 degrees to the point A4 based on the tilt angle range exemplified above.

  Furthermore, in this embodiment, the distance from the point A5 to the outer edge of the land is obtained as the land protrusion width. And the measured value of this land protrusion width and the volume of the cream solder read from the inspection data management device 102 in advance (measured by the solder printing inspection machine 10 with respect to the land corresponding to the soldering part currently being processed) The estimation table shown in FIG. 5 (1) is collated with the combination of the above, and the angle θx suitable for this combination is specified (for example, the angle range indicated by the group corresponding to the combination of the cream solder volume and the land protrusion width) The intermediate value of the angle or the lower limit of the angle range is defined as θx.) The angle θx is applied to the point A5.

  Thereafter, as shown in the graph on the right hand side of FIG. 6, the approximate curve representing the change in the inclination angle along the measurement line L from the relationship between the coordinates of the points A1 to A5 and the angles applied to the points A1 to A5. Derive M. Further, the height of the solder corresponding to the point A5 is calculated by integrating each point included in the range from the point A1 to the point A5 of the approximate curve M, and this is the wetting height of the solder after the reflow. .

The inclination angle indicated by each color area has a predetermined width, but with respect to the boundary position between the color areas, a highly reliable inclination angle is obtained, and the coordinates and inclination angles of the points A1 to A4 are obtained. It is considered that the approximate curve obtained from the above relationship appropriately represents the change in inclination along the measurement line. In addition, for dark areas where the tilt state cannot be measured, the approximate tilt angle can be estimated by collating the estimation table created from the sample data with the actual measurement data of the cream solder volume and land protrusion width. By complementing this estimation result, the wetting height of the entire fillet can be obtained.
Therefore, because the cream solder volume and land protrusion width before the reflow process vary, even if the fillet shape varies in the same part of the same type of board, the measurement error for each fillet is made smaller than before. It becomes possible.

  Depending on the part, the solder fillet after reflow is short and steep, so there may be almost no red or green color area in the image. Using the angle range and the inclination angle estimated for the dark region, the same measurement process as described above can be performed.

  In addition, the tilt angle estimated from the estimation table is not limited to a specific value, and a plurality of angles may be derived and the above measurement process may be performed for each angle. For example, by performing the above measurement using the upper limit angle and the lower limit angle of the angle range indicated by the group corresponding to the combination of cream solder volume and land protrusion width, the wetting height of the solder after reflow A numerical range of possible values may be obtained.

  Further, in the soldering inspection machine 30, red, green, and blue color lights are simultaneously irradiated from different directions of incidence angles and imaged, and each color region is extracted from the generated image and shown in FIG. 6. Although the calculation has been performed, the present invention is not limited to this, and an inspection machine of a type in which a light source corresponding to each direction is sequentially turned on and imaging is performed every time it is turned on may be used. In this case, a region having a high luminance is extracted from the soldered portion in the image generated by each imaging, and the same processing as that in FIG. 6 is performed based on the relationship between these regions.

  Moreover, although the example which uses the volume of the cream solder calculated | required with the solder printing test | inspection machine 10 for the estimation process was demonstrated above, the measurement parameter of the front process used for estimation is not limited to this. For example, an estimation process using the relative position or printing range of the cream solder with respect to the land, the average value of the height of the cream solder, or the like can be performed.

  In the above-described embodiment, the land protrusion width is measured by the soldering printing machine 30. However, the land protrusion width may be obtained using the result of the measurement process by the component inspection machine 20. For example, for a component that may cause solder to reach the top of the component electrode, the land protrusion width may be obtained based on the state of the component before the reflow process.

  In addition, if an inspection machine having a three-dimensional measurement function is used as the component inspection machine 20, it is possible to perform an estimation process using the heights of the parts and the component electrodes. For example, the amount of solder that flows between the component electrode and the land in the reflow process is estimated based on the volume of cream solder and the height of the component electrode, and the measured wet height is corrected based on the estimated result. May be.

  FIG. 7 shows a schematic procedure regarding the soldering inspection. Here, for the sake of simplicity of explanation, it is assumed that only processing by one substrate is shown, and the number of times of imaging with respect to this substrate is one, and there is one soldering site processed for each component. In the soldering inspection, the wetting height of the solder after reflow is measured by the method shown in FIG. 6, but the measurement parameter of the other process used for the process of estimating the angle θx corresponding to the dark region is cream solder. It is assumed that any type of measurement parameter is used, not limited to

  First, the board S to be inspected is imaged (step S1), and the following loop LP1 is performed for each component. Hereinafter, processing in the loop LP1 will be described.

  In step S2, based on the registered setting data, a detection area is set in a range including the part to be inspected and the corresponding land in the image, and the land and the part are detected from this area. Land detection is performed by a method of extracting a pixel group having high luminance, and detection of a component is performed by a method of extracting a registered color of the component.

  Next, in step S3, based on the detection result in step S2, the inspection region F shown in FIG. 6 is set in a range including the land and component electrodes, and the land protrusion width is measured. In step S4, each color area and dark area are detected from the inspection area F.

  In step S5, a measurement line L is set based on the detection result of each region, and the coordinates of the end points (points A2, A3, A4) between the regions and the end points (points A1, A5) on both sides on this line are set. measure. When the detected color area is small, the measurement target point is adjusted accordingly.

  In step S6, the inspection data management apparatus 102 is accessed, and the measurement data (measurement values of parameters used in the estimation process) performed by the other inspection machines 10 and 20 are read at the location corresponding to the part being processed. . In step S7, the inclination angle θx corresponding to the dark region is estimated using the measurement data read in step S6.

  In step S8, the corresponding inclination angle is applied to each coordinate measured in step S5 to obtain the curve M shown in FIG. 6, and further integrated to calculate the wetting height of the solder after reflow. To do. In step S9, the quality of the soldered part is determined by comparing the height with a determination reference value.

  Hereinafter, the loop LP1 is performed for each component to be inspected. Actually, since most components have a plurality of soldering portions, the loop LP1 is executed for the number of soldering portions.

  When processing for all components is completed, the determination results for these components are integrated to determine whether the entire board is good or defective, and the inspection result information is output to the inspection data management device 102 or the like. This inspection result information can include determination results and measurement results in the loop LP1 every hour in addition to the overall determination results.

  In the inspection of the above embodiment, the wetting height is obtained in order to determine the wetting state of the solder after reflow. However, the present invention is not limited to this, and the curve M shown in FIG. Analysis may be made to determine if the change in fillet slope is appropriate.

  Next, the configuration of the soldering inspection machine 30 is not limited to that shown above, and an inspection machine having the same configuration as the solder printing inspection machine 10 shown in FIG. 3 may be used. In the soldering inspection in this case, after obtaining the height data of each point of the solder after reflow based on the principle of the phase shift method, the three-dimensional shape of the solder after reflow is obtained by associating the coordinates of each pixel with the height data. Can be restored and its suitability can be determined. However, even with this configuration of the inspection machine, since the striped pattern is projected from an obliquely upward direction of the substrate, the reflected light with respect to the projected pattern can be incident on the camera 2A at a location where the slope of the solder fillet after reflow is steep. There is a problem that height data cannot be calculated.

  In view of the above points, in the embodiment shown in FIG. 8, when a phase shift method inspection machine is used for soldering inspection, the reflection light image of the projection pattern is not obtained because it is in the vicinity of the component. The height is estimated on the basis of measurement data obtained by an inspection machine in another process for a portion where the height could not be measured.

  Hereinafter, the inspection procedure of this embodiment will be described with reference to FIG. In this example as well, as in the previous example of FIG. 7, only the processing procedure for one substrate is shown, and the number of soldering parts of each component is limited to one.

  First, in step S21, an image for three-dimensional measurement is generated by performing projection processing and imaging of a striped pattern a plurality of times. Next, in step S22, an image for appearance measurement is generated by performing imaging under white illumination by the illumination device 2A.

Thereafter, the loop LP2 is executed for each part to be inspected.
First, in the first step S23 of the loop LP2, lands and parts are detected using the appearance measurement image obtained in step S2. Since the detection method is substantially the same as step S2 in FIG. 7, detailed description thereof is omitted.

  Next, in step S24, an inspection area is set in a range including a part of the land and parts detected in step S23. Since the camera 2A is common, this inspection region can also be applied to a three-dimensional measurement image.

  Therefore, in the next step S25, the above inspection region is applied to the three-dimensional measurement image, and for each pixel in the region, three-dimensional measurement based on the phase shift method is performed to calculate height data. Since this process is the same as that for obtaining the solder cream height of the soldering inspection machine 10, detailed description thereof is omitted.

  Next, in step S26, by comparing the land or part range detected in step S23 with the three-dimensional measurement result, the pixel group having the height data corresponding to the part and the height data corresponding to the solder after reflow are obtained. And having a pixel group.

  In step S27, a pixel group that is in the vicinity of the component and for which height data could not be calculated because a change in brightness phase was not detected is extracted, and a range including these pixel groups is specified as an unmeasured region. . Then, from the inspection data management device 102, the measurement data obtained by the measurement processing of another inspection machine for the inspection target part is read (step S28), and the estimation table is collated with the read measurement data to determine the unmeasured area. Height data is estimated (step S29). Thereby, the height data of the steeply inclined surface in the vicinity of the part can be acquired. In this estimation process, estimation may be performed by adding the measurement result of the own apparatus to the measurement data obtained by the inspection machine in another process. For example, by using the pixel group having the height data corresponding to the post-reflow solder specified in step S26, a curve approximating the solder volume and fillet inclination corresponding to these pixel groups is obtained, and these results and You may perform the estimation process using the measurement data by the inspection machine of another process.

In step S30, the three-dimensional shape of the fillet of the post-reflow solder is restored using the height data in each pixel of the pixel group having the height data corresponding to the solder after reflow and the pixel group in the unmeasured area. In step S31, various measurement processes are performed on the restored three-dimensional shape. For example, the volume, the angle change of the inclined surface of the fillet, the length and width of the fillet, the peripheral length of the solder after reflow, and the like can be calculated.
In step S32, good / bad of the soldering part is determined using each measured value.

  Thereafter, similarly, the processing of the loop LP2 is sequentially performed on the parts to be inspected. Finally, in step S33, whether the whole substrate is good or bad is determined, and the determination result is output.

  According to the above processing, the height data of the steep slope that cannot be obtained only by ordinary three-dimensional measurement can be acquired, and the three-dimensional shape of the entire fillet can be accurately restored. Can greatly increase.

  In the example of FIGS. 7 and 8 described above, the measurement data obtained by the inspection machines 10 and 20 in other processes is read from the inspection data management apparatus 102. However, the present invention is not limited to this. , 20 may receive measurement data directly.

  In each embodiment, information in a table format is registered as information indicating the causal relationship between the feature of the part that cannot be directly measured by image processing and the measurement data in another process. A function indicating the relationship may be derived and registered. Even when the estimation table is registered, the estimation table is not limited to the one that directly derives the feature of the part that is difficult to measure in the vicinity of the part, and the estimation table that is configured to derive the feature of the entire fillet may be registered. In this case, in the estimation process, for example, a plurality of fillet shape data candidates are extracted from the estimation table based on the result of the measurement process in another process for the part corresponding to the soldered part to be inspected. Of these, the one closest to the shape indicated by the actual measurement data in the soldering inspection machine 30 may be selected.

  Next, the apparatus that performs the estimation process is not limited to the soldering inspection machine 30. For example, the inspection data management apparatus 102 executes the estimation process using the measurement data received from the inspection machines 10 and 20, and the estimation result. May be provided to the soldering inspection machine 30. In this way, the calculation load in the soldering inspection machine 30 can be reduced. Further, if the estimation process is performed prior to the soldering inspection, the inspection efficiency can be increased and the tact time can be reduced.

  FIG. 9 shows the flow of information between the devices, taking as an example a case where the estimation process is performed by the inspection data management device 102. In this example, it is assumed that the soldering inspection machine 10 may apply any of the configurations shown in FIGS. 2 and 3 and will be described without specifying the content of the soldering inspection and the measurement data used for the estimation process. .

  The inspection program management apparatus 101 provides an inspection program to each of the inspection machines 10, 20, and 30 in accordance with each model ((a) (b) (c) in FIG. 9). These programs are created for each part type based on the inspection criteria for parts belonging to that part type, and are registered in the inspection program management apparatus 101 as library data. Each inspection machine 10, 20, 30 reads library data of necessary component types from the inspection program management device 101 based on the design data of the board to be inspected, and edits them in a state linked to the position information of the components. To use.

  Based on the provided inspection programs, the solder printing inspection machine 10 and the component inspection machine 20 set an inspection area for each inspection target part and perform a measurement process for a predetermined parameter. Defect is judged. Then, the inspection result information including the measurement data for each inspection area is transmitted to the inspection data management apparatus 102 ((d) in FIG. 9).

  The inspection data management apparatus 102 stores these pieces of transmission information in a format that can be read out for each inspection machine, each board, and each part. The inspection data management apparatus 102 is provided with an estimation table for each part type and an estimation processing program in advance from the inspection program management apparatus 101 ((e) in FIG. 9). The inspection data management apparatus 102 targets a board that has been inspected by these inspection machines 10 and 20 based on these tables and programs and inspection result information from the solder printing inspection machine 10 and the parts inspection machine 20. For each component on the board, feature data (such as an inclination angle and height data in the vicinity of the component) necessary for measurement processing for soldering inspection is estimated.

  On the other hand, the soldering inspection machine 30 processes the image of the soldering part to be inspected based on the inspection program provided from the inspection program management apparatus 101, acquires characteristic data necessary for the inspection, and manages the inspection data. The apparatus 102 is accessed, and the feature data estimated by the inspection data management apparatus 102 regarding the soldering site being processed is provided ((f) in FIG. 9). Then, final measurement processing is executed based on the feature data and the feature data acquired by the device itself, and the good / bad of the soldered portion is determined by comparing the measured value with the determination reference value. Then, inspection result information in which the determination result and the measurement data used for the determination are collected is transmitted to the inspection data management apparatus 102 ((G) in FIG. 9).

  In each of the above-described embodiments, the part that is in the vicinity of the part of the soldering part and does not show the characteristic necessary for measurement is the target of the estimation process. The estimation process may be performed including a portion that appears but is unclear. In addition, a portion that has no possibility of appearing in the image of the substrate after the reflow process, such as solder between the component and the land, may be the target of estimation. For example, based on the relationship between the volume of cream solder measured by the soldering inspection machine 10 and the volume of solder after reflow measured by the soldering inspection machine 30, the amount of solder after reflow under the component can be estimated. As an example.

DESCRIPTION OF SYMBOLS S Board | substrate 1 Control processing part 2 Camera 3 Illumination part 4 Board | substrate stage 10 Solder printing inspection machine 11 Solder printing apparatus 20 Component inspection machine 21 Mounter 30 Soldering inspection machine 31 Reflow furnace 102 Inspection data management apparatus

Claims (10)

A camera is disposed on the surface of the board that has been subjected to the reflow process among a plurality of processes carried out for the production of the component mounting board, and the board image is generated on the board using the image of the board generated by the camera. A method for inspecting the soldering state of the parts of
Assuming that the configuration added to the substrate in at least one of the plurality of steps performed before the reflow step is measured before starting the next step, the soldering portion to be inspected Regarding the characteristics of the location where it is difficult to determine the state in the image by the camera, the causal relationship with the measurement value obtained for the location corresponding to the soldering site in the measurement process prior to the reflow process is specified in advance, and the relationship Registered causal information indicating
A first step of processing the range including the soldering site in the image and obtaining feature data representing the shape of the solder for the soldering site to be inspected after the reflow process; and the soldering site The second step of acquiring the measurement value obtained in the measurement process prior to the reflow process for the location corresponding to, the causal relationship information registered for the soldering site and the measurement value acquired in the second step Using the third step of estimating the feature of the soldering site where it is difficult to determine the state in the image, and complementing the estimation result in the third step to the feature data acquired in the first step, A soldering inspection method characterized in that the fourth step of determining whether the soldering part is good or bad is executed.   The soldering inspection method according to claim 1, wherein as a measurement process in the process before the reflow process, measurement is performed on cream solder printed on each land of the substrate in the solder printing process.   As the measurement process in the process before the reflow process, the measurement process for the cream solder printed on each land of the board in the solder printing process and the measurement process for the component mounted on the board in the component mounting process are performed. As a premise, the causal relationship information indicating the causal relationship between the combination of the measurement values obtained by these measurement processes and the feature of the portion of the soldering portion to be inspected that is difficult to determine the state in the image by the camera is registered. Item 2. The soldering inspection method according to Item 1.   The measurement process for the cream solder printed on the land of the substrate is performed by measuring at least one of the volume, area, height, printing position, and printing range of the cream solder. Soldering inspection method.   The soldering inspection method according to claim 3, wherein at least one of a position, a size, a positional relationship with a land, and a height of the component is measured as a measurement process for the component mounted on the substrate.   In the first step, a region where the feature data should be acquired but not acquired is extracted at a position near the part of the soldering site in the image, and the feature of this region is extracted in the third step. The soldering inspection method according to claim 1, wherein the soldering inspection method is estimated. For a board that has completed up to the reflow process among a plurality of processes that are carried out for the production of a component mounting board, the board is imaged by a camera arranged toward the surface of the board, and the generated image An inspection machine for inspecting the soldering state of the components inside
Assuming that the configuration added to the substrate in at least one of the plurality of steps performed before the reflow step is measured before starting the next step, the soldering portion to be inspected As a result of performing the process of identifying the causal relationship with the measurement value obtained for the part corresponding to the soldered part in the measurement process prior to the reflow process with respect to the feature of the part whose state is difficult to discriminate in the image by the camera Storage means in which the causal relationship information set based on
An image processing unit that processes a range including a soldered portion to be inspected in the image, and acquires feature data representing a shape of the solder;
A measurement value input means for inputting a measurement value obtained in a measurement process prior to a reflow process for a portion corresponding to the soldering portion to be inspected;
With respect to the soldering part to be inspected, the state of the soldering part is determined in the image using the causal relationship information registered in the storage unit and the measurement value input by the measurement value input unit. An estimation means for estimating the characteristics of the difficult part,
A determination unit that complements the estimation result by the estimation unit to the feature data acquired by the image processing unit, and determines whether the soldering part is good or bad.
Soldering inspection machine provided. In the soldering inspection machine according to claim 7,
An illuminating device that irradiates light from a plurality of directions with different incident angles on a substrate to be inspected, and an imaging control unit that generates an image for inspection by operating the camera under illumination by the illuminating device; Further comprising
In the storage means, among the soldering parts to be inspected, an inclination angle of a part that is a dark region because a reflected light image by light from the illumination device is not obtained in the image in the vicinity of the component. The causal relationship information indicating the causal relationship with the measurement value obtained by the measurement process for the cream solder printed on the land in the solder printing process is registered,
The image processing means extracts a region where a reflected light image corresponding to the illumination light appears from a range including the soldered portion to be inspected in the image for each direction of the illumination light, and in the vicinity of the component in the image. Extract the dark areas that occur,
The estimation means uses the causal relationship information registered in the storage means with respect to the soldered part to be inspected and the measurement value input by the measurement value input means to determine the inclination angle of the location corresponding to the dark region. Estimate
The determination means supplements the inclination angle estimated by the estimation means to the dark region, and also determines the amount of solder calculated from the incident angle of the illumination light corresponding to the reflected light image corresponding to the illumination light from each direction. A soldering inspection machine that applies inclination angles and uses these inclination angles to determine whether or not the wettability of the fillet at the soldering site is appropriate. In the soldering inspection machine according to claim 7,
A projection device for projecting a striped pattern image onto a substrate to be inspected, and causing the projection device to project the pattern image while periodically moving the pattern along the arrangement of the stripes, and the timing of each projection Imaging control means for operating the camera in accordance with
The storage means includes a height of a portion of the soldering portion to be inspected that is in the vicinity of a part and from which a reflected light image of the pattern image cannot be obtained, and a cream printed on the land in the solder printing process. Causal relationship information indicating the causal relationship with the measurement value obtained by the measurement process for solder is registered,
The image processing means uses the plurality of images generated by imaging while projection of one cycle of the pattern image is performed, for each pixel within a range including a soldered portion to be inspected, for the one cycle. The height corresponding to the pixel is measured based on the phase of the brightness change that occurred during the projection of the pixel, and a pixel group that represents the height of the solder fillet is extracted based on the measurement result. Extract a pixel group whose height could not be measured because the change in brightness was not obtained in the vicinity of
The estimation unit uses the causal relationship information registered in the storage unit with respect to the soldered part to be inspected and the measurement value input by the measurement value input unit, and the pixel group whose height could not be measured. Estimate the height,
The determination means supplements the height estimated by the estimation means to the pixel group whose height could not be measured, and the height of each height in the pixel group and the pixel group representing the height of the solder fillet. A soldering inspection machine that uses values to determine the suitability of the fillet at the soldering site. An inspection machine deployed in a reflow process among a plurality of processes carried out for the production of a component mounting board and inspecting the board after the reflow process, and after the process deployed in at least one process before the reflow process An inspection machine that inspects the board of the apparatus, and an information management apparatus that takes in the inspection result information from each inspection machine by communication and manages the inspection result information for each inspection machine in a readable manner for each board and for each inspection target part,
The inspection machine in the reflow process processes a range including a camera arranged toward the surface of a substrate to be inspected and a soldered portion to be inspected in an image generated by the camera, and forms a solder shape. Image processing means for acquiring feature data to represent,
The information management device includes:
Regarding the feature of the location where it is difficult to determine the state in the image by the camera among the soldering sites to be inspected by the inspection machine in the reflow process, with respect to the location corresponding to the soldering site in the inspection machine in the process prior to the reflow process Storage means for registering the causal relationship information set based on the result of performing the process of specifying the causal relationship with the measurement value obtained by the measurement process,
A measurement value input means for inputting a measurement value obtained by a measurement process by an inspection machine in a process prior to a reflow process for a location corresponding to the soldering part to be inspected;
With respect to the soldering part to be inspected, the state of the soldering part is determined in the image using the causal relationship information registered in the storage unit and the measurement value input by the measurement value input unit. An estimation means for estimating the characteristics of the difficult part,
Transmission means for transmitting the estimation result by the estimation means to the inspection machine in the reflow process,
The inspection machine in the reflow process further includes a determination unit that complements the estimation result transmitted from the information management device to the feature data acquired by the image processing unit, and determines whether the soldered portion is good or defective. Board inspection system.

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