JP2008064631A - Substrate appearance inspecting apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To inexpensively improve the precision for recognizing an identification code of a substrate. <P>SOLUTION: If the processing of reading the two-dimensional code as the encoded identification code of the substrate is failed when the substrate to be inspected is carried, an image used for reading is displayed on a display panel. Three options regarding a method for processing the re-read two-dimensional code are displayed on the same screen, and a user selection is accepted. If the image correction option is selected among the options, an operation for correcting the displayed image is accepted, and an inspecting apparatus uses the corrected image and implements the reading process again. If the image reading option or the real thing reading option is selected, a code entry from a two-dimensional code reader connected to the apparatus is accepted, and the entered code is recognized as identification data of the substrate. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  In the present invention, a substrate that has undergone predetermined processes (solder printing process, component mounting process, reflow process, etc.) relating to the manufacture of a component mounting board is imaged under predetermined illumination, and the generated image is used in the preceding process. The present invention relates to a substrate visual inspection apparatus for inspecting a configuration (cream solder, component, solder fillet, etc.) added to a substrate.

  This type of substrate appearance inspection device (hereinafter sometimes simply referred to as “inspection device”) is generally incorporated into a substrate production line, and sequentially inspects the substrate conveyed by the conveyor from the previous process. Each time the inspection of one substrate is completed, the inspection result is output.

  In particular, when it is necessary to specify a substrate to be inspected, a unique identification code is assigned to each substrate, and the code and the inspection result are associated with each other and managed. In this case, a barcode or two-dimensional code representing the above identification code is marked on each substrate, and the code is imaged by the imaging unit prior to inspection, and the identification code is read using the generated image. (See Patent Document 1, paragraphs 0044, 0045, 0050, and 0095.)

JP 2005-286309 A

  However, since the optical system in the inspection apparatus is optimized for the purpose of detecting the part to be inspected, imaging may not be performed under conditions suitable for reading the optical information code, and thus the code reading may fail. . For example, the optical system of the inspection apparatus after the reflow process is configured to image specularly reflected light from a solder fillet (see Patent Document 2), but the substrate surface is generally low in specular reflectivity. If the specular reflectivity of the information code is low, an image that is difficult to distinguish between the substrate surface and the code is generated, and an error may occur when detecting or decoding the code. In addition, because the entire image of the code is not generated due to the deviation of the marking position of the code or the incomplete conveyance state of the substrate, the reading process may be impossible.

Japanese Patent Publication No.6-1173

  As a method for solving the above problem, firstly, a method for arranging an optical information code reader (generally called “code reader”) in the inspection apparatus or slightly upstream of the apparatus is considered. However, when an inspection apparatus is provided for each process as in the above-mentioned Patent Document 1, if one reading apparatus is provided for each inspection apparatus, the cost increases accordingly. Considering the ratio of failing to read a code with an image generated by an inspection device and the fact that even if reading fails, it can be dealt with by correcting the image, it is uneconomical to introduce a reading device for each inspection device. It is. However, although it is difficult to correct the image, it is also true that the code can be easily read if there is a reader dedicated to the optical information code.

  The present invention has been made in consideration of the above-described circumstances, and an object thereof is to improve the reading accuracy of an identification code on a substrate at a low cost and to enhance the convenience of an inspection apparatus.

  A substrate appearance inspection apparatus according to the present invention displays a substrate stage for supporting a substrate to be inspected, an illumination unit and an imaging unit disposed above the substrate stage, and an image generated by the imaging unit. And an inspection unit that inspects the quality of the inspected part on the substrate using an image generated by the imaging unit, and an optical information code attached to a predetermined position on the substrate prior to the inspection. Comprising a code recognition means for recognizing the identification code of the substrate to be shown, and a result output means for outputting the result of the inspection in association with the identification code recognized by the code recognition means. A connector for connecting the optical information code reader to the processing unit is provided.

  The code recognizing unit executes a process of causing the imaging unit to image the optical information code and a process of reading the optical information code using an image generated by the imaging, and recognizes the read code as an identification code of the substrate . On the other hand, when the reading of the optical information code fails, the code recognition unit displays the image generated by the imaging on the display unit, and inputs the code from the reading device and corrects the image displayed on the display unit. Will be accepted. Further, when a code is input from the reading device in this state, the input code is recognized as a board identification code. When a correction operation is performed on the image, the optical information code is used using the corrected image. The reading process is executed again.

  If the entire image of the optical information code is included in the image generated by the imaging unit, even if reading fails, the brightness of the image can be adjusted and a margin around the code can be secured. Reading may be possible by performing a simple correction operation. According to the above configuration, when the reading of the optical information code fails, the image generated for the reading is displayed on the display unit, so that the user can easily make a readable image on this screen. It can be determined whether or not it can be corrected. If it is determined that the correction can be easily performed, the user performs a correction operation on the image, and causes the inspection apparatus to read the optical information code again. On the other hand, when it is determined that the user cannot easily correct the image, a hand-held reader is connected to the connector, and the optical information code is read using the reader.

  As described above, since the correspondence method can be switched depending on the state of the image generated by the inspection apparatus, the identification code recognition process can be performed more efficiently and reliably. In addition, if it is a hand-held reader, it can be connected appropriately and is easy to carry, so one reader can be shared by multiple inspection devices, and the cost of introducing the reader can be reduced. Can be lowered.

  The reading device is preferably connected to the connection terminal via a cable having a length that allows the code reading surface to reach both the screen of the display unit and the substrate stage. In this way, it is possible not only to cause the reading device to read the actual optical information code but also to read the optical information code displayed on the screen of the display unit. The reading device includes an illumination unit suitable for reading an optical information code, and can generate an image suitable for code reading by processing such as switching of illumination conditions. Even if it is somewhat unclear, it is considered that reading is often possible if the entire image of the code is generated. In general, since the substrate stage is provided inside the inspection apparatus, reading the code on the substrate takes time and effort such as opening the apparatus. It is very simple.

  Further, the substrate appearance inspection apparatus according to a preferred aspect includes an operation unit for manually inputting the identification code into the code recognition means. In this case, when the code recognition unit fails to read the identification code and displays an image on the display unit, the code recognition unit is in a state where it can accept a code input from the operation unit, and identifies the code input from the operation unit. Recognize as a code.

  According to the above aspect, when a character string indicating the content of the identification code is written in the vicinity of the optical information code, such as a barcode, the user displays the character string displayed on the screen of the display unit. After confirmation, the identification code can be manually input from the operation unit.

  According to the substrate appearance inspection apparatus having the above configuration, when reading of the optical information code indicating the identification code fails, the user can modify the image from the display screen of the image used for the reading process or external reading. Since it is possible to determine which method using the apparatus is appropriate and execute the method determined to be appropriate, the process of recognizing the identification code of the substrate can be performed efficiently. In addition, since it is possible to cope with the method of appropriately connecting a hand-held reader without always connecting an optical information code reader, the recognition accuracy of the identification code can be improved at low cost, and the convenience of the inspection device Can be increased.

FIG. 1 shows the external appearance of a substrate visual inspection apparatus to which the present invention is applied.
This board appearance inspection apparatus 1 (hereinafter, simply referred to as “inspection apparatus 1”) is an apparatus for inspecting the mounting state of each part, the solder fillet, etc., on a substrate subjected to a component mounting process or a reflow process. is there. The upper half of the apparatus main body 10 is provided with a space (not shown; hereinafter referred to as “imaging space”) for supporting the substrate and performing imaging. A door portion 17 is provided at a position in front of the imaging space, and a display panel 14 and a plurality of switches 15 are provided on the front surface thereof. A connector 16 for connecting a two-dimensional code reader, which will be described later, is provided below the door portion 17.

  A carry-in port (not shown) for taking a substrate to be inspected into the imaging space is provided on one side surface of the apparatus main body 10, and a carry-out port for carrying out the substrate that has been inspected on the other side surface. (Not shown) is provided. Further, a circuit board constituting the controller 100 described later is incorporated at an appropriate position in the apparatus main body 10.

FIG. 2 shows the configuration and electrical configuration of the optical system of the inspection apparatus 1.
In the imaging space of the inspection apparatus 1, a camera 11, an illumination unit 12, and a substrate stage 13 are provided. The substrate stage 13 includes a table 131 for supporting the substrate S to be inspected, a moving mechanism 132 including an X-axis stage and a Y-axis stage (both not shown).

  The camera 11 and the illumination unit 12 constitute an optical system called “color highlight method”. The camera 11 generates a color still image, and is arranged above the substrate stage 13 with the imaging surface facing downward and the optical axis aligned with the vertical direction. The illumination unit 12 includes three annular light sources 12R, 12G, and 12B disposed between the substrate stage 13 and the camera 11. These light sources 12R, 12G, and 12B emit red, green, and blue chromatic light, respectively, and are arranged in a state in which each central portion is aligned with the optical axis of the camera 11. In addition, the light sources 12R, 12G, and 12B are set to have different diameters so that the substrate S can be irradiated with light from different directions.

  The controller 100 that controls the camera 11, the illumination unit 12, and the substrate stage 13 includes a computer-based control unit 101, an image input unit 102, an imaging control unit 103, an illumination control unit 104, an XY stage control unit 105, and a memory 106. A CD-ROM drive 107, a communication interface 108, a code input unit 109, and the like are provided.

  In addition, the display panel 14 and the input unit 16 shown in FIG. In addition to the switch 15 shown in FIG. 1, the input unit 16 includes a keyboard and a mouse (not shown).

  The image input unit 102 includes an interface circuit for the camera 11 and the like. The imaging control unit 103 is for outputting a timing signal instructing imaging to the camera 11.

  The illumination control unit 104 controls the turning on / off operation of each of the light sources 12R, 12G, and 12B of the lighting unit 12 and adjusts the amount of light. The XY stage control unit 105 controls the movement timing and movement amount of the substrate stage 13.

  The memory 106 stores a program used for inspection of each part to be inspected, inspection reference data, and the like. The control unit 101 executes a series of processes related to inspection using these programs and inspection reference data. Roughly described, the movement of the substrate stage 13 is controlled, so that the camera 11 takes an image while sequentially adjusting the visual field of the camera 11 to a plurality of positions on the substrate S. Further, an inspection region is set in each generated image, and processing such as detection of a region to be inspected, measurement of a position and an area, and determination of suitability of a measurement value is executed.

  Further, a two-dimensional code in which an identification code of the substrate S is encoded is attached to a predetermined position of the substrate S to be inspected by the inspection apparatus 1 (for example, direct marking on the substrate S by a laser or a marking process). .) When the substrate S is carried into the substrate stage 13, the control unit 101 first performs imaging by aligning the camera 11 with the marking position of the two-dimensional code, and executes a two-dimensional code reading process using the generated image. The read code is recognized as an identification code. When a series of inspections is completed, a data file in which the inspection results are collected (hereinafter referred to as “inspection result data file”) is created. The file name including the identification code read from the two-dimensional code is created in this file. Give.

  A connector 16 provided on the front surface of the apparatus main body 10 is for connecting a hand-held two-dimensional code reader. The code input unit 109 is an interface circuit for taking in a code read and output by the two-dimensional code reader and inputting the code to the control unit 101.

  FIG. 3 shows the appearance of the two-dimensional code reader 2 connected to the inspection apparatus 1 described above. The two-dimensional code reader 2 has a configuration in which a code reading surface 21 is provided in the upper half of the front surface and a grip 22 is provided below the code reading surface 21. An operation button 23 for instructing the start of reading is provided on the side surface of the two-dimensional code reader 2.

  Although the internal structure of the two-dimensional code reader 2 is not shown, known structures such as a light source for illumination, an image sensor, and a control board are incorporated. A cable 24 including an output signal line from the control board is drawn out from the bottom surface of the apparatus main body. Further, a connector (not shown) that fits the connector on the inspection apparatus side is attached to the distal end portion of the cable 24. The cable 24 is set to a length that allows the reading surface 21 to reach the substrate stage 13 inside the inspection apparatus 1 sufficiently.

  In the inspection apparatus 1 of this embodiment, when the reading of the two-dimensional code in the apparatus fails, the two-dimensional code is read again. This rereading process is performed by using the above-described two-dimensional code reader 2 or by correcting the image used in the failed reading process and processing the corrected image again on the inspection apparatus side. it can. In this embodiment, an image used for reading is displayed on the display panel 14 and an operation for selecting a rereading method is accepted on the display screen.

  FIGS. 4A to 4C show examples of screens displayed on the display panel 14. An image display window 31 is set on the left side of the screen 30, and an image of the two-dimensional code used for reading is displayed therein. This image is cut out from an image generated by the camera 11 for reading a two-dimensional code. The area to be cut out is predetermined.

  Further, three options indicating a re-reading method are displayed on the lower right of the screen 30. In addition, the currently selected option is surrounded by a frame 33, and a mouse cursor 32 indicating the selection position is displayed. The user can confirm selection of an option by performing a click operation with the mouse cursor 32 in alignment with the frame 33.

  “Image correction” of the three options is for the user to select a method of correcting the image used for reading and performing the reading process again on the inspection apparatus side using the corrected image. It is. “Read image” and “read actual object” are for selecting a method for performing a reading process by the two-dimensional code reader 2, but the objects to be read are different.

  In “read image”, the image of the two-dimensional code in the window 31 is set as a reading target. On the other hand, “read actual object” uses an actual two-dimensional code marked on the substrate S as a reading target.

  FIG. 4A shows an example in which “image correction” is selected. In the image of this example, the two-dimensional code itself is clear, but a shadow is generated in a part of the periphery. In order to recognize a two-dimensional code in an image, a margin of a predetermined width is required around the code. Therefore, if there is a shadow as described above, the margin cannot be secured and the code cannot be recognized. However, it is considered that if the correction for deleting the shadow is performed, the code can be recognized and the reading process can be executed without any problem.

  FIG. 4B shows an example in which “read image” is selected. The image of this example includes the entire image of the two-dimensional code, but the two-dimensional code is unclear due to reasons such as the illumination not being suitable for the code. However, since the two-dimensional code reader 2 has advanced functions for reading the two-dimensional code such as adjusting the illumination conditions until an image suitable for reading the code is generated, even the above-described image can be read. It is possible to generate a suitable image and read the code.

  For the image in FIG. 4B, it is possible to select “image correction” and perform processing for adjusting the brightness of the image, but this type of adjustment may be performed by trial and error. In many cases, it is difficult to obtain an image suitable for reading with a single adjustment. Therefore, in this case, it is considered more efficient to select “read image”, and there is a high possibility that the examination can be promptly shifted. However, since it may be better to adjust the brightness of the image after the image correction before reading with the two-dimensional code reader 2, in this embodiment, after selecting “image correction”, A method of re-reading with an image and a method of reading a corrected image with the two-dimensional code reader 2 can be selected.

  FIG. 4 (3) shows an example in which “Read Real” is selected. In this example, since the whole image of the two-dimensional code is not generated, “image correction” or “read image” cannot be handled, and it is necessary to image the two-dimensional code again.

  In the above example, when the selection of “read real” is confirmed, the door portion 17 is unlocked and can be opened. Therefore, the user can open the door 17 and move the two-dimensional code reader 2 to the substrate S on the substrate stage 13 to execute a two-dimensional code reading operation.

  However, only the image in the predetermined area is displayed in the window 31 of the screen 30, and the entire image generated by the camera 11 may include the entire image of the two-dimensional code. . In such a case, “image correction” may be selected and the entire image generated by the camera 11 may be displayed so that the region to be cut out can be changed.

  According to the screen displays shown in FIGS. 4 (1) to 4 (3), the user can check the image used for the reading process and select an optimum method from the three methods. Therefore, the code re-reading process can be executed efficiently and accurately, and the process can be quickly shifted to the inspection.

  In the example of FIG. 4, the option is displayed on the screen 30 and the method is selected. However, for “read image”, the selection operation is not performed and the code is input from the two-dimensional code. The input code may be recognized as an identification code. As for “reading the actual object”, if the unlocking of the door portion 17 can be manually performed, the selection operation may be omitted.

FIG. 5 shows a flow of processing executed by the inspection apparatus 1.
In the first ST1 (ST is an abbreviation of “step”. The same applies to the following), when the loading of the substrate S to the substrate stage 13 is accepted, in ST2, the marking position of the two-dimensional code is preliminarily taught. The field of view of the camera 11 is matched and imaging is performed. In ST3, a two-dimensional code reading process is executed using the image generated by the imaging in ST2. If this reading is successful, ST4 becomes “YES” and the process proceeds to ST11, where the read code is recognized as the identification code of the substrate S.

  On the other hand, if reading fails, the process proceeds to ST5, and the image of the two-dimensional code used for reading is displayed on the display panel 14 together with options. If “image correction” is selected on this display screen, ST6 becomes “YES” and the process proceeds to ST9.

  On the other hand, when “read image” or “read actual object” is selected on the display screen of the two-dimensional code, ST6 becomes “NO” and the apparatus waits for the code input from the two-dimensional code reader 2. Here, the user performs a reading operation with the reading surface 21 of the two-dimensional code reader 2 directed toward the two-dimensional code on the image or the substrate S, and reading processing executed by the two-dimensional code reader 2 in response to the operation. If successful, the read code is input to the control unit 101. As a result, ST7 becomes “YES” and the process proceeds to ST8, where the input code is recognized as the identification code of the substrate S.

  When “image correction” is selected and the process proceeds to ST9, for example, an edit screen on which an image in the window 31 is enlarged is displayed on the display panel 14 to accept a user's correction operation. When the correction operation is completed and the editing screen is closed, the display panel 14 displays two options of “use corrected image” and “read image” together with the corrected image. . Here, when the user selects “use corrected image”, ST10 becomes “YES” and the process returns to ST3 to execute a reading process using the corrected image. If this reading is successful, the process proceeds from ST4 to ST11 in the same manner as described above, and the identification code of the substrate S is recognized. On the other hand, when the user selects “read image” and performs the reading operation with the reading surface 21 of the two-dimensional code reader 2 facing the corrected image, the process proceeds to ST8 and input from the two-dimensional code reader 2. The obtained code is recognized as the identification code of the substrate S.

  As described above, after the identification code of the substrate S is recognized in ST8 or ST11, the process proceeds to ST12, and a series of processing for inspection is executed. When all inspections are completed, an inspection result data file having the recognized identification code as a file name is created and stored in the memory 106. This inspection result data file is also output to an external device (not shown) as necessary. When a defective part is detected in the inspection, data obtained by combining the data related to the defect and the identification code is output to the external device.

  After this, if there is a substrate to be inspected, ST13 becomes “YES”, the process returns to ST1, and the above procedure is repeated.

  In the above embodiment, the identification code of the substrate S is encoded into a two-dimensional code, but it may be encoded into a barcode instead. Since a character string indicating the contents is often appended to the barcode, when such a character string is written, when an image is displayed in response to reading failure, the above-mentioned 3 In addition to the method of one option, a method of receiving code input from the keyboard may be executed.

It is a front view which shows the external appearance of the board | substrate external appearance inspection apparatus concerning one Example of this invention. It is a block diagram which shows the structure and electrical structure of the optical system of a board | substrate external appearance inspection apparatus. It is a perspective view which shows the external appearance of a two-dimensional code reader. It is explanatory drawing which shows the example of the screen displayed at the time of reading failure. It is a flowchart which shows the flow of the process in a board | substrate external appearance inspection.

Explanation of symbols

S Substrate 1 Substrate visual inspection device 2 Two-dimensional code reader 11 Camera 12 Illumination unit 13 Substrate stage 14 Display panel 16 Connector 100 Controller 101 Control unit

Claims (3)

A substrate stage for supporting a substrate to be inspected, an illumination unit and an imaging unit disposed above the substrate stage, and a display unit for displaying an image generated by the imaging unit; An inspection means for inspecting the quality of a part to be inspected on the substrate using an image generated by the method, and a code for recognizing an identification code of the substrate indicated by an optical information code attached to a predetermined position of the substrate prior to the inspection In a board appearance inspection apparatus comprising: a recognition unit; and a result output unit that outputs a result of the inspection in association with an identification code recognized by the code recognition unit.
On the outer peripheral surface of the apparatus main body, a connector for connecting a hand-held optical information code reader to the processing unit is provided,
The code recognition means includes
A process of causing the imaging unit to image the optical information code and a process of reading the optical information code using an image generated by the imaging are performed, and the read code is recognized as a substrate identification code. When reading of the information code fails, the image generated by the imaging is displayed on the display unit, and the code input from the reading device and the correction operation on the image displayed on the display unit can be received. When the code is input from the reading device below, the input code is recognized as the identification code of the board, and when the correction operation is performed on the image, the identification code is read using the corrected image. Substrate visual inspection apparatus to be executed again.   2. The board appearance inspection apparatus according to claim 1, wherein the reading device is connected to the connection terminal via a cable having a length in which a code reading surface reaches both the screen of the display unit and the substrate stage. A substrate visual inspection apparatus according to claim 1 or 2,
An operation unit for manually inputting the identification code in the code recognition means;
When the code recognizing unit fails to read the identification code and displays an image on the display unit, the code recognizing unit further receives a code input from the operation unit. Recognizing board appearance inspection device.