JP2009198182A - Visual examination method of electronic component - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a visual examination method of an electronic component capable of inspecting the joined state of a shielding lid member and a circuit mounted base in the electronic component provided with the shielding lid member. <P>SOLUTION: In the visual examination method of the electronic component composed of the component mounted base 2 and the metal lid member 3 which covers at least one side of the base 2 and is joined and held to the electrode 4 provided to the base 2 through solder 5, halation is produced by throwing light with a definite luminous intensity on the connection part 6 of the lid member 3 and the base 2 from its back to more darkly express the recessed part 20 between the lid member 3 and the base 2 than another part to detect a defective place. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an inspection method for an electronic component, and more particularly to an appearance inspection method for an electronic component including a metal lid for shielding, such as a tuner component.

  A mobile phone having a television receiving function is equipped with a tuner component for receiving and demodulating television radio waves. This tuner component has a structure in which a main circuit portion is covered with a metal lid and grounded in order to prevent radio wave interference due to a telephone call or the like. The lid is to form a latching part by bending a metal thin plate by press processing, and this latching part is inserted into through holes and notch parts provided at the four corners of the substrate on which the tuner circuit is mounted. After the fitting, the electrodes provided adjacent to these through holes and notches are joined and fixed via solder, a conductive adhesive or the like.

  In the final process of tuner component manufacturing, it is necessary to judge whether the lid is securely bonded and fixed to the board based on the appearance, so that surface roughness and waviness such as solder for bonding are not erroneously detected as defects. Normally, a plurality of falling illuminations having different wavelengths and incident angles are used as light sources for inspection, and pass / fail is determined by image processing.

As prior art document information relating to this application, for example, Patent Document 1 is known.
JP 2004-198231 A

  The above method uses illumination of two types of incident angles from directly above and obliquely above the substrate. In order to emphasize the unevenness of the inspection object, it is necessary to adjust the incident angle of illumination according to the unevenness. For this reason, when the unevenness is stable, detection can be performed with high accuracy. However, when the unevenness varies, there is a problem that the detection accuracy decreases.

  Therefore, an object of the present invention is to improve detection accuracy with a simple structure.

  In order to achieve this object, the present invention includes a substrate on which a component is mounted, a metal lid that covers at least one surface of the substrate and is joined and held to an electrode provided on the substrate via solder. A method for inspecting an electronic component comprising: illuminating a connection portion between the lid and the substrate with light having a constant illuminance from the back surface thereof, and forming a recess between the lid and the substrate in another The defective part was detected by making it appear darker than the part.

  In the electronic component appearance inspection method according to the present invention, the halation is illuminated by illuminating the connection portion connecting and fixing the metal lid and the substrate with light of a constant illuminance from the back surface (back surface) side. Is generated. This halation eliminates the shadows caused by unevenness on the solder surface that joins and fixes the lid and the electrode on the board side, and makes only the deep recesses between the lid and the board darker, resulting in high precision. In addition, it is possible to detect a bonding failure between the lid and the substrate.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a perspective view for explaining an example of an electronic component which is an object to be inspected using the inspection method of the present invention, and is a tuner component for television reception mounted on a mobile phone or the like.

  The object to be inspected 1 has electronic parts such as ICs and chip parts mounted on at least one surface of a substrate 2 made of a ceramic or resin multilayer board, and receives and modulates TV radio waves by these electronic parts. A circuit for demodulating is formed. These circuits are covered with a metal lid 3 and grounded in order to prevent interference with radio waves for telephone calls of mobile phones.

  The lid 3 is formed by bending a metal thin plate by press working or the like, and has a casing shape having one surface as an opening and an engaging portion 3a. As shown in FIG. 2, the locking portion 3a is inserted or fitted into a through hole or notch provided in a corner portion or the like of the substrate 2 or locked along the side surface. The connecting portion 6 is formed by joining and fixing the electrode 4 of the substrate 2 provided in the vicinity of the notch portion and the solder 5 or the like.

  When a good fillet is not formed between the engaging portion 3a of the lid 3 and the adjacent electrode 4, the bonding strength of the lid 3 is lowered, and the lid 3 is dropped during mounting or when the mounted mobile phone is dropped. A defect such as coming off from the substrate 2 occurs. Therefore, in the inspection process, it is necessary to inspect the bonded state of the lid 3 and the substrate 2 by their appearance to determine whether they are good or bad.

  FIG. 3 is a side view showing an example of the configuration of the appearance inspection apparatus used in the inspection process.

  The appearance inspection apparatus according to the present embodiment includes an optical unit 12 including a plurality of light sources 7, 8, 9, and 10 and a camera 11, and a determination unit for processing images taken by the camera 11 and the like to determine pass / fail. 13.

  First of all, the optical unit 12 includes first, second, and third falling light sources 8, 9 for irradiating diffused light on a stage 14 for mounting and fixing the inspection object 1. 10 and an imaging camera 11 are arranged on the same axis. Further, the stage 14 has a transmissive light source 7 therein, and illuminates the inspected object 1 on the stage with a constant illuminance from the back surface through a translucent acrylic plate 15 as a light source for transmissive illumination. Is.

  The falling light sources 8, 9, 10 and the transmissive light source 7 and the camera 11 are all connected to a determination unit 13 including a monitor, a personal computer and the like via a control unit. The appearance inspection apparatus according to the present embodiment includes a plurality of light sources 7, 8, 9, and 10. The light source 7, 8, 9, and 10 are appropriately switched according to the inspection item, or a combination of a plurality of light sources is optimally selected. This is because a plurality of inspection items such as chipping, scratches, and solder shortage can be carried out by one unit. Table 1 shows an example of inspection items and a light source to be selected.

  The above inspection items are all performed by placing the inspection object 1 on the stage 14 with the bottom surface side (external connection terminal 16 side) of the substrate 2 shown in FIG.

  The contents of the inspection shown in Table 1 will be described below.

  First, the inspection object 1 having an electronic component mounted on one surface of the substrate 2 is transported and placed on the stage 14 with the external connection terminal 16 side as an upper surface. Next, the transmitted light source 7 in the stage 14 is turned on to illuminate the inspected object 1 from the back side, and the contour is extracted from the image. Then, the accuracy of the outer shape, that is, the dimensions of each part is measured from the extracted contour, and the quality is determined from the measurement result and the presence or absence of cracks, chips, and the like. Thus, at the time of contour extraction, the transmission light source 7 is selected to use the difference in contrast and lightness between the object 1 and the background consisting of the stage 14, and the determination unit 13 uses binarization processing or the like. To detect the contour.

  Since the acrylic plate 15 can increase the contrast between the DUT 1 and the background by selecting a color complementary to the DUT 1, the contour can be detected more easily and with high accuracy. It becomes possible to do. In addition, the acrylic plate 15 is selected because it is inexpensive this time, but the same effect can be obtained with colored translucent glass.

  Next, in order to prevent connection failure, the external connection terminal 16 is inspected for contamination due to foreign matter adhesion or the like. Since at least the outermost surface of the external connection terminal 16 is formed of gold, nickel, tin, or the like, sufficient contrast can be obtained with respect to other portions, that is, resin or ceramic portions. Therefore, it is sufficient to select an illumination that is just above the object to be measured 1 and close to the coaxial illumination. In the present embodiment, the third falling light source 10 disposed at the highest position from the object to be inspected 1 is used. select.

  Next, inspection of the chip on the surface of the substrate 2 on the external connection terminal 16 side is performed. In this case, since the chipping is not the entire chip but an inspection of a part of chipping or cracking on the surface of the inspection object 1, in order to emphasize the shadow, not the coaxial illumination but the inspection object 1 as much as possible. Lighting from a shallow angle. For this reason, the first falling light source 8 disposed at the lowest position on the inspection object 1 is selected.

  At this time, the transmission light source 7 is turned off, and the inspection accuracy can be improved by lowering the reflectance of the surface of the acrylic plate 15 such as that which is complementary to the object 1 to be inspected or embossing.

  Next, it is inspection of the surface flaw. Unlike cracks and chips, scratches are narrow and shallow. For this reason, the scratches are emphasized by scattered light by turning on the first falling light source 8 and illuminating the inspection object 1 from a shallow angle. Further, the inspection accuracy can be increased by turning on the transmissive light source 7 at this time. This is because the brightness of the object under test 1 is lowered by increasing the brightness of the background. By doing in this way, the to-be-inspected object 1 is displayed darkly, and the scattered light by a damage | wound is further emphasized.

  Finally, the inspection of the connecting portion between the lid 3 and the substrate 2 which is the point of the present invention will be described.

  The lid 3 for preventing the interference between the radio wave for communication and the radio wave for TV is once locked in a notch provided in the side surface of the substrate 2 on which the circuit is formed or a through hole in the final process. The electrode 4 provided on the external connection terminal 16 side is connected and held using solder 5 or a conductive paste.

  The state at this time is shown in FIG. 4 is a cross-sectional view taken along the line A-AA in FIG. 2, and is a cross-sectional view illustrating a connection state of the lid body 3, particularly a connection state between the lid body 3 and the electrode 4.

  The connecting portion 17 is in a non-defective state, and the connecting portion 18 is an example when defective. In the connection part 17 which is a non-defective product, the solder 5 is sufficiently supplied to the gap part 19 as well as the electrode 3 on the cover 3 and the inspection object 1. On the other hand, sufficient solder 5 is not supplied to the defective connection portion 18. Therefore, the connection portion 18 is in a state where the gap between the lid 3 and the inspection object 1 is exposed as a deep recess 20 on the surface. This indicates that sufficient solder 5 is not supplied into the gap 19 and the bonding strength between the device under test 1 and the lid 3 is low. The concave portion 20 exposed on the surface of the connecting portion 18 is detected, and the quality of the connection state between the lid 3 and the inspection object 1 is judged.

  In order to detect the deep recess 20 in the connecting portion 18, the following inspection method is used. First, as illumination, the second and third falling light sources 9 and 10 are simultaneously turned on together with the transmissive light source 7. Further, the transmissive light source 7 illuminates the camera 11 with high illuminance that causes halation, not low illuminance.

  FIG. 5 shows an example of an inspection image when halation is caused in the camera 11. As shown in FIG. 5, in the connecting portion indicated by the arrow B, the solder 5 is also displayed in white together with the locking portion 3a, and only the defective deep concave portion 20 is highlighted in black. What is important here is that not only the halation by the transmissive light source 7 but also the second and third falling light sources 9 and 10 are turned on simultaneously. Although minute irregularities are formed on the surface of the solder 5, in order to detect only the deep depressions 20 as defects without detecting these minute irregularities as defects, 10 is turned on at the same time, and these fine irregularities are erased white together with the background.

  By using halation as described above, it is possible to detect the irregular shape stably and accurately even with a material having high reflectance, and to shorten the detection time using image processing.

  FIG. 6 is an enlarged view of the connecting portion 6 of FIG. In the conventional inspection method, the determination area 21 must be set inside the electrode 4 because the contrast between the defective portion and the surrounding area is used. This is because the outside of the electrode 4 is made of resin or ceramic, so that it is prevented from being erroneously determined to be defective due to the difference in brightness.

  In the above-described embodiment, the transmission light source 7, the first, second, and third falling light sources 8, 9, and 10 have been described as having the same wavelength, but each may have a different wavelength. . By using light sources of different wavelengths, the reflectance of the surface of the object to be inspected 1 can be further increased and the defective portion can be detected with higher accuracy. Further, when the color of the inspection object 1 is different due to product type switching, such as resin or ceramic, the illumination color can be changed and adjusted by appropriately illuminating a plurality of light sources having different wavelengths. As a result, particularly when the camera 11 capable of color photographing is used, the accuracy of detection of contours and the like can be increased by the complementary color relationship with the inspection object 1. Furthermore, by mixing the illumination light of the transmissive light source 7 through the acrylic plate 15, the color of the acrylic plate 15, that is, the background color of the inspection object 1 can be changed and adjusted. It is possible to increase the accuracy of inspection by increasing the difference in contrast and brightness, and to deal with various colors of the inspection object 1 without changing the light source, so that the productivity of the inspection process can be increased.

  As described above, in the present embodiment, the periphery of the electrode 4 and its periphery are erased white by halation. Therefore, even if the determination area is shifted, the brightness is the same and no erroneous determination occurs. Therefore, by measuring the position of the DUT 1 in advance during the above-described inspection of the external accuracy, the inspection area 22 can be easily determined, and the inspection area 22 can be set appropriately wide. Even if a slight misalignment occurs between the inspection items, it is possible to detect a defect.

  The electronic component appearance inspection method according to the present invention generates halation by irradiating light with a constant illuminance from the back surface (back surface) side of the connecting portion that connects and fixes the metal lid and the substrate. Is. This halation eliminates the irregularities on the solder surface that joins and fixes the lid and the electrode provided on the board side, and at the same time raises the concave part with the board, which is poorly joined to the lid, and darkly rises, resulting in high accuracy. In particular, the present invention is useful for a method for inspecting the appearance of an electronic component having a shielding metal lid.

The perspective view explaining an example of the inspection object using the inspection method of the present invention Bottom view of the object to be inspected in FIG. The figure explaining an example of a structure of the test | inspection apparatus in this Embodiment A-AA sectional view of FIG. The figure which shows an example of the test | inspection image using the test | inspection method in this Embodiment The figure explaining an example of the test | inspection area | region of the test | inspection method in this Embodiment

Explanation of symbols

2 Substrate 3 Lid 4 Electrode 5 Solder 6 Connection 20 Recess

Claims (2)

A method for inspecting the appearance of an electronic component comprising a substrate on which a component is mounted, and a metal lid that covers and holds at least one surface of the substrate, and is joined to and held by an electrode on the substrate via solder, Illuminate the connection between the lid and the substrate with light of constant illuminance from the back side, and generate halation, and detect the defective part by raising the recess between the lid and the substrate darker than other parts. Appearance inspection method for electronic parts. The electronic component visual inspection method according to claim 1, wherein the joint between the lid and the substrate is illuminated with a plurality of lights having different wavelengths.