Appearance inspection device and appearance inspection method for semiconductor device

Abstract

To provide an appearance inspection device and appearance inspection method for a semiconductor device capable of inspecting the entire circumferential part of a circular column while being fixed without rotating an inspection object even if the inspection object is the fixed circular column.SOLUTION: An appearance inspection device for a semiconductor device that inspects the surface of an inspection object being the semiconductor device includes: an inspection object being a circular column that is fixed to a carrier tape; a conveyance unit that conveys the inspection object; an illumination unit that irradiates the surface of the inspection object; a reflection unit that reflects the irradiation light from the illumination unit to illuminate the inspection object; a plurality of camera units that continuously capture images; and an image processing unit that processes imaging signals from the camera units.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an appearance inspection of a semiconductor device, and more particularly to an appearance inspection apparatus and method for inspecting the surface condition of a cylindrical inspection target for a semiconductor device. [Background technology]

[0002] It is generally known that an image recognition device is used for visually inspecting the surface condition of a semiconductor device.

[0003] Patent Document 1 discloses a configuration of a linear light source, a reflector, a camera, and an image processing device in a defect inspection device for a cylindrical inspection object, which makes it possible to inspect the outer wall surface defects of the cylindrical inspection object.

[0004] Patent Document 2 discloses a surface inspection device that rotates a cylindrical inspection object placed on two rotating rollers, thereby enabling inspection of the entire surface of the cylindrical inspection object. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2003-4651 A [Patent Document 2] JP 2005-62101 A Summary of the Invention [Problem to be solved by the invention]

[0006] In some cases, a specific semiconductor device is inspected visually when its package is fixed rather than as a single package.

[0007] However, while the conventional technology is effective when the image processing is performed in the cylindrical extension direction of the object to be inspected or when the object to be inspected can be rotated, when the cylindrical object to be inspected is transported in a direction perpendicular to the extension direction and the object to be inspected is fixed, it is difficult to simultaneously image the entire circumference of the cylinder.

[0008] Therefore, the present invention has been made to solve the above-mentioned problems, and aims to provide an appearance inspection apparatus and an appearance inspection method for semiconductor devices that can inspect the entire circumference of a cylindrical object while it remains fixed, without rotating the object, even if the object is fixed and cylindrical. [Means for solving the problem]

[0009] In order to solve the above problems, the present invention has the following configuration. The semiconductor device visual inspection apparatus of the present invention is an visual inspection apparatus for inspecting the surface of an inspection object which is a semiconductor device, and is composed of a cylindrical inspection object fixed to a carrier tape, a transport unit for transporting the inspection object, an illumination unit for illuminating the surface of the inspection object, a reflection unit for reflecting the light emitted by the illumination unit to illuminate the inspection object, a plurality of camera units for continuously capturing images, and an image processing unit for processing the image capture signals from the camera units. Effect of the Invention

[0010] The present invention aims to provide an appearance inspection device and method for semiconductor device that is equipped with multiple cameras and can adjust the amount of light for the cylindrical surface of an inspection object using lighting and a reflector, thereby making it possible to inspect the entire circumference of the cylindrical object while it remains fixed, without rotating the object, even if the object is fixed in place. In particular, it is possible to provide an appearance inspection apparatus capable of inspecting the appearance of a taped axial type semiconductor device in the all-around direction, and it is possible to prevent insufficient adhesion and outflow of resin flash from the lead portion of the semiconductor device. [Brief description of the drawings]

[0011] [Figure 1] 1 is a schematic diagram of a semiconductor device visual inspection apparatus according to a first embodiment of the present invention. [Diagram 2] 1 is a side view of a semiconductor device visual inspection apparatus according to a first embodiment of the present invention. [Diagram 3] FIG. 2 is a diagram showing a state in which the semiconductor device according to the first embodiment of the present invention is transported. [Figure 4] 1 is a schematic diagram showing a configuration of a semiconductor device visual inspection apparatus according to a first embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, the embodiments of the present invention will be described in detail with reference to the drawings. However, the drawings are schematic, and the dimensional ratios and the like are different from the actual ones. Therefore, the specific dimensions and the like should be judged in light of the following explanation. In addition, it goes without saying that the dimensional relationships and ratios of the drawings may differ from one another. EXAMPLES

[0013] Fig. 1 is a schematic diagram of a semiconductor device visual inspection apparatus according to a first embodiment of the present invention. Fig. 2 is a side view of the semiconductor device visual inspection apparatus according to the first embodiment of the present invention. Fig. 3 is a diagram showing a transport state of the semiconductor device according to the first embodiment of the present invention. Fig. 4 is a schematic diagram showing a configuration of the semiconductor device visual inspection apparatus according to the first embodiment of the present invention.

[0014] Axial diodes, which have a cylindrical body and coaxial leads protruding from both ends, are known as semiconductor devices. When the leads are protruding and the device is sealed with resin, resin flash may adhere to the lead surface.

[0015] In the visual inspection process for semiconductor devices, workers visually inspect taped axial diodes (semiconductor devices). However, because the leads are round and connected with taping, it is difficult to see the entire circumference in a two-dimensional visual inspection, and there was a concern that defective products with flash adhesion would be shipped out.

[0016] In addition, when performing image inspection using an imaging device, since the object to be inspected is cylindrical, it can be identified if the resin flash adhesion is directly above. However, if the resin flash adhesion is in a position such as to the side, image inspection can be difficult due to the arrangement of lighting and camera position.

[0017] As shown in FIG. 1, the visual inspection device 1 of the present invention is composed of a transport unit 7 that transports an inspection object which is a semiconductor device 10, an illumination unit 3 that irradiates the surface of the inspection object, a reflection unit 4 that reflects the light emitted by the illumination device to illuminate the inspection object, a plurality of camera units 2 that continuously capture images, and an image processing unit 8 that processes the image capture signals from the camera units 2.

[0018] The inspection object, which is the semiconductor device 10, is an axial type diode with a cylindrical resin-sealed package body and thin lead wires protruding coaxially from both ends. In addition, both ends of the leads are taped with carrier tape 11, and the semiconductor device 10 is fixed and connected in a ladder shape (see FIG. 3). At this time, the semiconductor device 10 cannot rotate.

[0019] In the conveying section 7, at the conveying section 7a on the loader side, the taped semiconductor device 10 wound on a reel (not shown) having an H-shaped cross section is pulled out and continuously conveyed horizontally, passing through the camera section 2, the lighting section 3, and the reflecting section 4, and then at the conveying section 7b, which is the unloader, the semiconductor device 10 is wound onto the other reel also having an H-shaped cross section.

[0020] The lighting unit 3 uses ring lights 3a and 3b, which are made up of many LED elements arranged in a circular pattern. The two ring lights are arranged with their light-emitting surfaces facing each other on both sides of the tape-wrapped semiconductor device 10 along which it is transported, to illuminate the surface of the semiconductor device 10. However, when arranged on both sides, it is difficult to shine light directly on the cylindrical surface, as they face each other in the same axial direction. For this reason, it was decided to use a reflector 4 to adjust the light from the lights 3a and 3b so that it can also illuminate in a perpendicular direction (see Figure 2).

[0021] The reflecting section 4 is a semi-cylindrical plate on which the semiconductor device 10 is placed from above and below with the curved surface facing inward. The cylindrical shape matches the circular shape of the ring illumination, surrounding the entire circumference of the semiconductor device 10 and reflecting the light emitted by the illumination section 2 to illuminate the semiconductor device 10. Furthermore, a minimum reflecting section opening 5 is provided at a position facing the passageway along which the semiconductor device 10 is transported and each camera section 3.

[0022] For the details of the illumination unit 3, it is advisable to use a ring-shaped illumination device with an adjustable light intensity. This can be easily prepared as it can be a commercially available product. It is also advisable to arrange them so that the light-emitting surfaces face each other across the semiconductor device 10. This does not interfere with the transportation of the semiconductor device 10 taped to the carrier tape 11 or with the arrangement of the camera unit 2. In addition, since the direction of the illumination light is parallel to the surface of the semiconductor device 10, it is possible to adjust the light so that the resin flash adhering to the leads of the semiconductor device 10 appears black and the rest of the resin flash appears white. This makes it possible to clearly distinguish the contrast of defective parts when imaging.

[0023] In detail, the reflecting section 4 is fitted to the ring-shaped outer circumference of the illumination section 3, and surrounds the entire circumference of the illumination section 3. However, since the semiconductor device 10, whose inside is fixed to the carrier tape 11, is transported, the reflecting section 4 is a combination of semicircular reflecting sections 4a and 4b. It is arranged parallel to the direction of the light emitted by the illumination section 3, and has an arc shape that reflects the light emitted from the illumination section 3 toward the semiconductor device 10. Here, the center point of the arc shape coincides with the semiconductor device 10 to be inspected. For example, the reflecting section 4 may be a white plate made of Teflon (registered trademark) with a thickness of 3 mm.

[0024] In detail, the camera unit 2 is installed in a direction perpendicular to the axis of the leads protruding from both ends of the package of the semiconductor device 10. It is attached to a mounting stay so that the imaging direction and distance can be changed. Here, three general commercially available image recognition cameras are prepared and used as camera units 2a, 2b, and 2c to capture images continuously. The number of pixels and resolution of the cameras can be appropriately selected depending on the imaging.

[0025] In addition, it was verified that the camera unit 5 can capture images of a cylindrical object up to a range of 160 degrees with one camera, so it was decided to place three cameras at 120 degrees. This is the best arrangement because it can capture images of the entire circumference. Here, the shooting direction of the camera units 2a, 2b, and 2c is perpendicular to the object to be inspected, and they are placed on the outside of the reflecting units 4a and 4b, respectively, and capture images from the reflecting unit openings 5a, 5b, and 5c opened in the reflecting plates 4a and 4b.

[0026] The image processing unit 8 processes the image (imaging signal) captured by the camera unit 2. It also adjusts the lighting unit 3. It also transmits an apparatus operation signal to the transport unit 7. It also transmits the imaging data of the image inspection and necessary data such as pass / fail judgment data to a control unit 9 such as a server (see FIG. 4).

[0027] Next, the appearance inspection method will be described in detail. Continuously transporting the inspection object (semiconductor device 10) The light emitted from the illumination unit 3 is reflected by the reflection unit 4 and directed at the object to be inspected. -A product presence / absence sensor is placed on the conveyor line to detect the object to be inspected (leads, etc.) The sensor signal is input to the image processing unit 8, and the three camera units 2 simultaneously capture images. The captured image information is output to the image processing unit 8. The image processing unit 8 judges whether or not there is an abnormality on the entire outer surface of the inspection object based on the captured image information, using a preset appearance judgment standard. - When a good product is detected, the visual inspection device operates continuously, and when a defect is detected, a signal is sent to the visual inspection device.

[0028] For example, an area for image inspection is set on the lead portion of the semiconductor device 10, and if any resin flash is found within the area, it is judged as defective and the visual inspection device is stopped. After that, the defective product is dealt with (removing the resin flash or replacing the defective product with a good product), the visual inspection device is restarted, and if the product is judged as good after the reinspection of the image inspection, the next inspection begins.

[0029] Next, the effects of the visual inspection apparatus 1 for the semiconductor device 10 according to the first embodiment will be described.

[0030] The present invention is an appearance inspection device for semiconductor devices that is equipped with multiple cameras and can adjust the amount of light for the cylindrical surface of an inspection object using illumination and a reflector. This allows the appearance inspection of the entire circumference of the cylindrical object while it is fixed, even if the inspection object is a fixed cylindrical object, without rotating the object. In other words, it is possible to inspect the appearance of taped cylindrical products (axial type semiconductor devices), and it is possible to prevent defective outflow of resin flash adhesion.

[0031] As described above, the embodiment of the present invention has been described, but the description and drawings forming a part of this disclosure should not be understood as limiting this invention. Various alternative embodiments, examples and operating techniques will become apparent to those skilled in the art from this disclosure.

[0032] In the above example, the reflective section 4 is made of two semicircular arcs joined together in cross section, but it may be a cylindrical reflective section provided with an opening through which the semiconductor device can be transported. The effect of this is to simplify the structure of the reflective section. [Explanation of symbols]

[0033] 1. Visual inspection equipment 2. Camera section (2a, 2b, 2c) 3. Lighting section (3a, 3b) 4, Reflective part (4a, 4b) 5. Reflector opening (5a, 5b, 5c) 7, Transport section (7a, 7b) 8. Image processing unit 9. Control unit 10. Semiconductor device 11. Carrier tape

Claims

1. An appearance inspection device for inspecting the surface of an inspection object which is a semiconductor device, comprising: the inspection object having a cylindrical shape fixed to a carrier tape; a transport unit for transporting the inspection object; an illumination unit for illuminating the surface of the inspection object; a reflection unit for reflecting the light emitted by the illumination unit to illuminate the inspection object; a plurality of camera units for continuously capturing images; and an image processing unit for processing the image capture signals from the camera units.

2. 2. The semiconductor device appearance inspection apparatus according to claim 1, wherein the illumination unit is a ring-shaped illumination device with adjustable light intensity, and is arranged so that the light-emitting surfaces face each other across the object to be inspected, and the direction of the illumination light is parallel to the surface of the object to be inspected.

3. 3. The semiconductor device visual inspection device according to claim 1, wherein the reflecting portion is a white plate, is arranged to surround the entire illumination portion in accordance with the ring-shaped outer periphery of the illumination portion, is arranged parallel to the direction of the light emitted by the illumination portion, has an arc shape that reflects the light emitted from the illumination portion toward the object to be inspected, and the center point of the arc in the cross section of the reflecting portion coincides with the object to be inspected.

4. 4. The semiconductor device appearance inspection device according to claim 1, wherein the imaging direction of the camera unit is perpendicular to the object to be inspected, and the camera units are arranged outside the reflector and capture images through an opening in the reflector.

5. A method for visual inspection of semiconductor devices, characterized in that light from an illumination unit is reflected by a reflection unit and directed at the object to be inspected, the object to be inspected which is continuously transported is simultaneously imaged by multiple cameras, a pass / fail judgment is made by an image processing device, and an external signal is output when a defect is detected.

Images