JP2009128268A - Pattern inspection device - Google Patents

Abstract

[PROBLEMS] To perform an inspection using both an epi-illumination image and a transmission illumination image at a speed similar to that of an inspection apparatus using only one image, and does not increase the installation area and is inexpensive. Providing equipment.
Cameras 5a and 5b that are arranged on the upper surface side and the lower surface side of a tape 10 (COF tape or the like) that is a film-like belt-like workpiece, and respectively image the upper surface side and the lower surface side of the tape 10; And an illumination device 4 that emits illumination light from the side. The illumination device has the function of the epi-illumination for generating the epi-illumination image representing the reflection state on the tape 10 and the function of the trans-illumination illumination for producing the transmission illumination image representing the distribution of transparency on the tape 10. Therefore, the incident illumination image and the transmitted illumination image related to one inspection pattern can be simultaneously acquired.
[Selection] Figure 1

Description

  The present invention relates to an apparatus for inspecting a circuit pattern provided on a film carrier tape for mounting electronic components.

Film carrier tapes for mounting electronic components include TAB (Tape Automated Bonding) tape, T-BGA (Tape Ball Grid Array) tape, ASIC (application).
Specific integration circuit) tapes, COF (Chip On Film) tapes, and the like are known. The film carrier tape for mounting an electronic component includes a transparent film, an electronic component attached to the film, a conductor pattern printed on the film for connecting the electronic components to each other, and the like. The film material needs to have heat resistance, and a polyimide resin having excellent heat resistance is used. A circuit pattern is constituted by a conductive pattern on the electronic component and the film. As a pattern inspection apparatus for inspecting a circuit pattern on a film carrier tape for mounting an electronic component, for example, a pattern inspection apparatus described in Patent Document 1 (Japanese Patent Application Laid-Open No. 2004-28597) is known.

  This type of pattern inspection device illuminates the tape to be inspected with illumination light, images the circuit pattern with an imaging device, acquires a circuit pattern image, compares the circuit pattern image with a reference pattern, and detects defects in the circuit pattern. Whether the circuit pattern is good or bad is determined by inspecting whether or not the circuit pattern exists. As a defect in the circuit pattern, a defect having a defect on a part of the upper surface side of the circuit pattern wiring (so-called “dish down”), a defect in which a part of the wiring becomes thinner than a specified value (so-called “thinning”), There is a defect (so-called “bottom of the bottom”) in which the width of the contact surface with the film in the wiring is wider than a specified value.

  FIG. 4 shows a main part of a pattern inspection apparatus (A) that acquires an epi-illumination image based on reflected light of a tape and a pattern inspection apparatus (B) that acquires a transmission illumination image based on light transmitted through the tape (transmitted light). FIG. 4A receives the reflected light from the tape 10 with the camera 5a while illuminating the tape 10 on which the conductor patterns D1 and D2 are printed with the illumination device 4, and images the tape 10 based on the reflected light. By doing so, an epi-illumination image of the tape 10 is acquired, and an epi-illumination image signal 501 representing the epi-illumination image is output. 4B, when the illumination device 4 illuminates the tape 10 on which the conductor patterns D1 and D2 are printed, the light (transmitted light) transmitted through the tape 10 is received by the camera 5b and transmitted light. By capturing the tape 10 based on the above, a transmitted illumination image of the tape 10 is acquired, and a transmitted illumination image signal 502 representing the transmitted illumination image is output. The conductor pattern D2 has defects such as bottom thickening R and dishdown S.

  FIG. 5 is a diagram for explaining a method for inspecting a pattern to be inspected by the pattern inspection apparatus of FIG. 4 (A) or FIG. 4 (B). 5A is a plan view showing a portion of the tape 10 on which the conductor patterns D1 and D2 are printed, FIG. 5B is a cross-sectional view taken along the line AA in FIG. 5A, and FIG. FIG. 5D is a diagram showing the illumination image signal 501, and FIG. 5D is a diagram showing the transmitted illumination image signal 502. The standard value of the width of the conductor pattern D1 is W1, the standard value of the width of the conductor pattern D2 is W3, and the standard value of the interval between the conductor patterns D1 and D2 is W2. Since the conductor pattern D2 has a bottom thickness R, the distance between the conductor patterns D1 and D2 on the AA line is reduced to W4. Further, the width from the left side surface of the conductor pattern D2 to the back end of the dishdown S is W5. An arrow 200 indicates the transport direction of the tape 10. In FIG. 5C, r and s indicate disturbances in the waveform of the epi-illumination image signal 501 corresponding to the bottom thickness R and the dishdown S, respectively.

  When the tape 10 shown in FIGS. 5A and 5B is inspected by the pattern inspection apparatus having the configuration shown in FIG. 4A, the epi-illumination image signal 501 shown in FIG. 5C is obtained from the camera 5a. In an epi-illumination image, a difference between W3 and W5 ′ can be detected relatively easily by setting a threshold value in a slightly bright area of the image signal range representing light and dark (for example, Th1 shown in FIG. 5C). Can do. Therefore, with respect to a defect on the upper surface side of the conductor pattern such as the dishdown S, the defect portion can be detected relatively easily by acquiring the epi-illumination image. On the other hand, the defect existing in the dark part of the image signal representing light and dark, such as the thickness R on the bottom side of the conductor pattern, changes even if the threshold value is set in a dark region (for example, Th2 shown in FIG. 5C). The point r is covered with variations in the reflectance of the film 10a as the base material, and it is difficult to detect the difference between W2 and W4 ′. Therefore, the defect existing on the bottom side tends to be difficult to recognize as a defect only based on the epi-illumination image.

  When the tape 10 shown in FIGS. 5A and 5B is inspected by the pattern inspection apparatus shown in FIG. 4B, the transmitted illumination image signal 502 shown in FIG. 5D is obtained from the camera 5b. Since the conductor pattern is made of metal and is opaque, the transmitted illumination image clearly shows a shadow (silhouette) on the surface where the conductor patterns D1 and D2 are in close contact with the film 10a. Therefore, as shown in FIG. 5D, by comparing the transmitted illumination image signal 502 with the threshold Th3, the interval W2 between the conductor patterns D1 and D2 can be measured, and by comparing W2 and W4, W2> W4 is satisfied. Since it understands, the space | interval of the conductor patterns D1 and D2 reduces, and it can determine easily that the conductor pattern D2 has the thickness R of the bottom.

  As described above, the inspection with the epi-illumination image has a drawback that it is difficult to detect the bottom thickness in the conductor pattern. However, in addition to the inspection with the epi-illumination image, the inspection with the transmission illumination image can be performed. The detection probability of bottom fatness can be improved. As with bottom thickening, the defect “thinning” in which the width of the conductor pattern is narrower than the standard can be easily obtained by acquiring a transmission illumination image of the conductor pattern and inspecting the silhouette of the contact surface between the conductor pattern and the film. Can be detected reliably. In this way, by acquiring both the incident illumination image and the transmitted illumination image and utilizing the characteristics of both, it is possible to improve the detection probability of the defect in the inspection pattern such as dishdown, thinning, and bottom thickening.

  Patent Document 1 includes an epi-illumination device that illuminates a tape from above and a transmitted-light illumination device that illuminates the tape from below in order to inspect one tape. A pattern inspection apparatus using both images is disclosed.

  FIG. 6 is a conceptual diagram showing a configuration of a conventional pattern inspection apparatus shown in FIG. This pattern inspection apparatus includes a control device (21), an imaging device (8) composed of a line sensor camera, an epi-illumination device (6), a tape pulling mechanism (22), a transmission illumination device (7), and a tape transport mechanism (23). And a defective punch mechanism (24). The control device (21) includes an imaging device (8), an epi-illumination device (6), a tape pulling mechanism (22), a transmission illumination device (7), a tape transport mechanism (23), a defective product punch mechanism (24), and the like. On the other hand, a control signal is transmitted at a predetermined timing of the inspection operation, and these are controlled. Master data (25) serving as a reference for pattern inspection is input in advance to the control device (21). The master data (25) includes two types of reference patterns, that is, a reference pattern of an image obtained by epi-illumination (epi-illumination image) and a reference pattern of an image obtained by trans-illumination (transmission illumination image). .

  The inspection by the pattern inspection apparatus of FIG. 6 is performed according to the following procedure. First, the tape transport mechanism (23) is driven by the controller (21), the tape (1) is transported, and the pattern to be inspected on the tape (1) stops at the imaging position. Next, tension is applied in the width direction of the tape (1) in a state where the peripheral portion of the tape (1) is sandwiched between the grip upper member (16) and the grip lower member (17) of the tape tension mechanism (22). It is done.

  Next, illumination light is irradiated to the inspection pattern on the tape (1) by the epi-illumination device (6). The reflected light from the pattern to be inspected is received by the CCD line sensor 81 of the imaging device (8). Next, the frame on which the epi-illumination device (6) and the imaging device (8) are fixed moves in the width direction of the tape (1) while the epi-illumination device (6) is illuminated. As a result, both the epi-illumination device (6) and the imaging device (8) move in the width direction of the tape (1), scan from one edge A to the other edge B of the tape (1), and the imaging device. In (8), an inspection pattern between the edge A and the edge B of the tape (1) is imaged. Information of the imaged pattern to be inspected is stored in the control unit (21) corresponding to the position in the width direction of the tape.

  When the imaging by the imaging device (8) reaches the edge B of the tape (1), the illumination by the epi-illumination device 6 is stopped, and the pattern to be inspected on the tape (1) is illuminated by the transmission illumination device (7). The transmitted light that has been irradiated with light and transmitted through the pattern to be inspected is received by the CCD line sensor (81) of the imaging device (8). Next, the frame is moved in the width direction of the tape (1) while being illuminated by the transmission illumination device (7). As a result, both the transmitted illumination device (7) and the imaging device (8) move in the width direction of the tape (1), scan from the other edge B of the tape (1) toward the one edge A, and the imaging device. In (8), the pattern to be inspected between the edge B and the edge A of the tape (1) is imaged. The information of the imaged pattern to be inspected is stored in the control unit (21) corresponding to the position in the tape width direction, as before. When the imaging by the imaging device (8) reaches the edge A of the tape (1), the illumination by the transmission illumination device (7) is stopped, the tape transport mechanism (23) is driven again, and the tape (1) is transported. The new pattern to be inspected is controlled to stop at a predetermined imaging position.

  As described above, two types of information obtained by the reciprocating movement of the imaging device (8), that is, information by reflected light (epi-illumination image) and information by transmitted light (transmission illumination image) on the inspection pattern on the tape (1). Is compared with each stored master data (25) in the control device (21) to determine pass / fail.

  The conventional pattern inspection apparatus described in Patent Document 1 described with reference to FIG. 6 includes an epi-illumination imaging step for obtaining an epi-illumination image by illuminating the tape (1) with the epi-illumination apparatus (6), and transmitted illumination. One pattern to be inspected is inspected by two processes including a transmitted light imaging process for obtaining a transmitted illumination image by illuminating the tape (1) with the apparatus (7). In the conventional pattern inspection apparatus described in Patent Document 1, when both the epi-illumination apparatus (6) and the transillumination apparatus (7) are turned on, the epi-illumination light and the transmitted light interfere with each other, and the epi-illumination image and the transmission are transmitted. Since both illumination images are unclear and defects in the pattern to be inspected cannot be found, the incident illumination device (6) and the transmission illumination device (7) are lit up alternately, and the incident light imaging step and the transmitted light imaging step are performed. One inspection pattern is inspected in two steps. As described above, the conventional pattern inspection apparatus described in Patent Document 1 has a problem to be solved that it is difficult to increase the speed of pattern inspection.

  If the conventional method of FIG. 6 is improved to increase the speed of pattern inspection, for example, the pattern inspection apparatus shown in the block diagram of FIG. 7 is used. 7 is equivalent to the control unit 11 (corresponding to the control device (21) in FIG. 6), the incident light inspection unit 31, the transmitted light inspection unit 32, and the puncher unit 80 (defective product punch mechanism (24 in FIG. 6). ), An unwinding portion 21, a winding portion 23, and air dancers 221, 222. The epi-illumination inspection unit 31 corresponds to the epi-illumination device (6) and the imaging device (8) in FIG. The transmitted light inspection unit 32 corresponds to the transmitted illumination device (7) and the imaging device (8) in FIG. The pattern inspection apparatus of FIG. 6 includes one inspection unit including the epi-illumination device (6), the transmission illumination device (7), and the imaging device (8), whereas the pattern inspection device of FIG. And the transmitted light inspection unit 32 are provided. The unwinding unit 21, the winding unit 23, and the air dancers 221, 222 correspond to the tape transport mechanism (23) in FIG.

  The control unit 11 includes a control unit main body 11a that is a server, a display 11b, and a keyboard 11c. The display 11b is controlled by the control unit main body 11a. The keyboard 11c is a terminal device that inputs commands and data to the control unit body 11a. For example, selection of data to be displayed on the display 11b is commanded to the control unit body 11a by operating the keyboard 11c.

  The unwinding unit 21 includes an unwinding reel 10a and a tension roller 25a mounted on a shaft 21a. The incident light inspection unit 31 includes a camera 5a, an incident illumination device 6, a stage 31a, and free sprockets 25b and 25c. The transmitted light inspection unit 32 includes a camera 5b, a transmitted illumination device 7, a stage 32a, and a free sprocket 25g. The puncher unit 80 includes three punchers 80a and a free sprocket 25e. The take-up unit 23 includes a take-up reel 10b and a tension roller 25f attached to a shaft 23a. The air dancer 221 includes eight sensors 22a, detects the position of the lower end of the tape 10 with the sensor 22a, and uses the tape transport mechanism of the incident light inspection unit 31 so that the tape 10 always maintains an appropriate length. I have control. The air dancer 222 includes eight sensors 22a, the position of the lower end of the tape 10 is detected by the sensor 22a, and the tape transport mechanism of the transmitted light inspection unit 32 is provided so that the tape 10 always maintains an appropriate length margin. I have control. In the figure, the tape 10 represents a tape while being unwound from the unwinding reel 10a and being wound on the take-up reel 10b.

  In the pattern inspection apparatus of FIG. 7, since the incident light inspection unit 31 and the transmitted light inspection unit 32 are arranged in cascade in the transport direction of the tape 10, one pattern to be inspected is irradiated with the incident light, and an incident illumination image is obtained. During acquisition, another pattern to be inspected can be simultaneously illuminated by the transmission illumination device 7 to obtain a transmission illumination image. Therefore, the pattern to be inspected can be inspected at a speed twice as high as that of the pattern inspection apparatus of Patent Document 1 shown in FIG. However, since the pattern inspection apparatus of FIG. 7 includes the incident light inspection part 31 and the transmitted light inspection part 32, as illustrated in FIG. And the length of one air dancer (1690 mm in the example of FIG. 7) becomes longer in the transport direction of the tape 10. The pattern inspection apparatus shown in FIG. 7 in which two inspection units are arranged in cascade so as to be simultaneously inspected by incident light and transmitted light requires a long installation place and a wide installation area. Further, since the incident light inspection unit 31 and the transmitted light inspection unit 32 each need a mechanism for controlling the tape conveyance with high accuracy, the manufacturing cost of the pattern inspection apparatus of FIG. 7 becomes expensive. Therefore, the apparatus of FIG. 7 has problems to be solved regarding the installation area and the manufacturing cost.

Therefore, an object of the present invention is to use both the epi-illumination image and the transmission illumination image related to the pattern to be inspected, and to inspect the pattern to be inspected at high speed. An object of the present invention is to provide a pattern inspection apparatus that can be installed in the same area as a pattern inspection apparatus that inspects a pattern to be inspected based on only one of the images, and that is low in manufacturing cost.
JP 2004-28597 A JP-A-11-296657

  In order to solve the above-described problems, the present invention provides the following means.

(1) In a pattern inspection apparatus that images a pattern formed on a film-like strip-shaped workpiece and inspects the appearance of the pattern,
A first imaging means arranged on one surface side of the belt-like workpiece and imaging the belt-like workpiece;
A second imaging means disposed on the other surface side of the belt-like workpiece and imaging the belt-like workpiece;
A pattern inspection apparatus comprising: illumination means for irradiating from one side of the belt-like workpiece.

(2) The illumination unit includes an observation window that is disposed between the light incident opening of the first imaging unit and the strip-shaped workpiece, and transmits light reflected by the strip-shaped workpiece.
The pattern inspection apparatus according to (1), wherein the first imaging unit images the strip-shaped workpiece through the observation window.

  (3) The pattern according to (1) or (2), wherein the illumination unit performs illumination for the first imaging unit and illumination for the second imaging unit at the same time. Inspection device.

  According to the present invention having the above-described configuration, it is possible to simultaneously obtain an epi-illumination image and a transmission illumination image relating to one inspection pattern by illuminating one inspection pattern in the strip-shaped workpiece with one illumination unit. Therefore, the inspection pattern can be inspected at high speed by using both the epi-illumination image and the transmission illumination image related to the pattern to be inspected, and the epi-illumination image or the transmission illumination image is one inspection unit. Therefore, it is possible to provide a pattern inspection apparatus that can be installed in the same area as a pattern inspection apparatus that inspects a pattern to be inspected based on only one of these two images and that is low in manufacturing cost.

  Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a conceptual diagram showing the configuration of an embodiment of a pattern inspection apparatus according to the present invention. This pattern inspection apparatus includes a control device 1, cameras 5a and 5b using a CCD line sensor as light sensing means, an illumination device 4, a tape pulling mechanism 3, a tape transport mechanism 2, and a defective product punch mechanism 8. The tape 10 is a film carrier tape for mounting an electronic component such as a COF tape, and is a kind of the above-described band-shaped workpiece. The cameras 5a and 5b correspond to the first and second imaging means described above, respectively.

  The control device 1 transmits a control signal to the cameras 5a and 5b, the illumination device 4, the tape pulling mechanism 3, the illumination device 4, the tape transport mechanism 2, the defective product punch mechanism 8 and the like at a predetermined timing of the inspection operation. Control these. Master data 9 serving as a reference for pattern inspection is input to the control device 1 in advance. The master data 9 includes two types of reference patterns, that is, a reference pattern a of an image obtained by epi-illumination (epi-illumination image) and a reference pattern b of an image obtained by trans-illumination (transmission illumination image). .

  The tape pulling mechanism 3 sandwiches the peripheral portion of the tape 10 by the grip upper member 31 and the grip lower member 32, applies a tension in the width direction to the tape 10, and improves the flatness of the tape 10. The illumination device 4 irradiates the pattern to be inspected on the tape 10 with illumination light. The illuminating device 4 is disposed between the light incident opening of the camera 5a and the tape 10, and includes an observation window through which light reflected by the tape 10 passes. The camera 5a images the tape 10 through the observation window. As an example of an illuminating device that includes an observation window and can illuminate an illumination target area with a uniform illuminance, there is an “imaging optical system of an image processing device” disclosed in Japanese Patent Laid-Open No. 11-296657. The camera 5 a receives reflected light from the pattern to be inspected by the CCD line sensor 51. Further, the camera 5 b receives the transmitted light from the pattern to be inspected by the CCD line sensor 52.

  The CCD line sensors 51 and 52 are formed by arranging a number of CCDs in a line. The CCD array direction in the CCD line sensors 51 and 52 is a direction orthogonal to the direction in which the tape 10 is conveyed (that is, the length direction of the tape 10). The tape transport mechanism 2 transports the tape 10 in the length direction intermittently at a constant time interval by a minute distance, which is a unit of the width of a pixel constituted by a CCD. The cameras 5a and 5b image the tape 10 at a timing synchronized with the intermittent conveyance.

  The inspection by the pattern inspection apparatus of FIG. 1 is performed according to the following procedure. First, when the tape transport mechanism 2 is driven under the control of the control device 1 to transport the tape 10 and the starting end of the pattern to be inspected on the tape 10 reaches the imaging position, the cameras 5a and 5b start imaging.

  Next, while the illumination device 4 is illuminating, the tape transport mechanism 2 transports the tape 10 in the length direction by the predetermined minute distance from the position of the start end mark of the pattern to be inspected. During this conveyance, the cameras 5a and 5b image the pattern to be inspected at the above timing. When the cameras 5a and 5b finish capturing the end mark of the pattern to be inspected, the tape transport mechanism 2 quickly transports the tape 10 until the position of the start end mark of the next pattern to be inspected is imaged by the cameras 5a and 5b. The tape 10 is conveyed by a minute distance at the timing of the previous period from when the position of the start mark is imaged. Hereinafter, similarly, the pattern to be inspected on the tape 10 is sequentially imaged by the cameras 5a and 5b.

  As described above, according to the conveyance of the tape 10, image data by reflected light of the inspection pattern on the tape 10 and image data by transmission light of the inspection pattern are obtained, and these image data signals are incident illumination image signals, respectively. 501 and the transmitted illumination image signal 502 are output from the camera 5a and the camera 5b. The epi-illumination image and the transmitted illumination image are respectively compared with the reference pattern a and the reference pattern b stored in the control device 1. The control device 1 determines pass / fail of the pattern to be inspected by this comparison.

  FIG. 2 is a diagram showing a method for determining pass / fail of the pattern to be inspected by the control device 1 in FIG. Since the main parts of the tape transport mechanism 2 in the pattern inspection apparatus of FIG. 1 are the unwinding unit 21 and the winding unit 23, FIG. 2 shows how the tape 10 is transported by the unwinding unit 21 and the winding unit 23. Is conceptually shown. Further, the control device 1 compares the epi-illumination image and the transmitted illumination image with the reference pattern a and the reference pattern b, respectively, and determines the quality of the pattern to be inspected as well as the entire pattern inspection device as described above. In FIG. 2, only the determination function is extracted and shown.

  The determination function includes determination units 1c and 1d, a combining unit 1e, and a final determination unit 1f. The reference patterns a and b are data stored in the determination units 1c and 1d, respectively. As described above, the pattern inspection apparatus that determines the quality of the pattern to be inspected using only the epi-illumination image has a weak point in detecting the thickness of the bottom. Therefore, the pattern inspection apparatus according to the present embodiment includes the epi-illumination image generation camera 5a and the transmission illumination image generation camera 5b. It has gained.

  With reference to FIGS. 1 and 2, a determination function for determining pass / fail of the pattern to be inspected in the embodiment of FIG. 1 will be described. Now, it is assumed that the pattern inspection apparatus in FIG. 1 is inspecting a region including the conductor patterns D1 and D2 shown in FIGS. The determination units 1c and 1d obtain data indicating that the conductor patterns D1 and D2 are present in predetermined regions from the reference patterns a and b, respectively. The determination unit 1c compares the epi-illumination image signal 501 with the first threshold, detects the widths of the conductor patterns D1 and D2, and the interval between the two conductor patterns, and determines the width and interval as the width and interval in the reference pattern a. Each is compared, a defect such as dishdown S is detected, and a determination signal 103 indicating a determination result (the presence or absence of a defect) is output. The determination unit 1d compares the transmitted illumination image signal 502 with the second threshold, detects the widths of the conductor patterns D1 and D2, and the interval between the two conductor patterns, and determines the width and interval as the width and interval in the reference pattern b. Each of these is compared, a defect such as a bottom thick R is detected, and a determination signal 104 representing the determination result is output.

  The synthesizing unit 1e receives the determination signals 103 and 104 output from the determination units 1c and 1d, respectively, and synthesizes the determination results represented by the determination signals 103 and 104 for each predetermined range in the pattern to be inspected. The degree is determined, and a composite determination signal 105 representing the determination is generated. The final determination unit 1f comprehensively evaluates the pattern to be inspected based on the degree of defects related to a certain range of the pattern to be inspected represented by the composite determination signal 105, and determines whether or not the pattern to be inspected is defective. As a result, the defective punch mechanism 8 determines whether or not a hole should be formed in the pattern to be inspected.

  FIG. 3 is a block diagram conceptually drawn for explaining the external dimensions of the pattern inspection apparatus of FIG. 3 includes a control unit 11 (corresponding to the control device 1 in FIG. 1), an inspection unit 30, a puncher unit 80 (corresponding to the defective product punch mechanism 8 in FIG. 1), an unwinding unit 21, and a winding unit. It consists of a take-out part 23 and an air dancer 22. The inspection unit 30 corresponds to a portion including the illumination device 4 and the cameras 5a and 5b in FIG. The unwinding unit 21, the winding unit 23, and the air dancer 22 correspond to the tape transport mechanism 2 in FIG. The tape pulling mechanism 3 in FIG. 1 is not shown in FIG.

  The pattern inspection apparatus of FIG. 7 described previously includes two inspection units, an incident light inspection unit 31 and a transmitted light inspection unit 32, in order to obtain an incident illumination image and a transmitted illumination image of the tape 10. On the other hand, the pattern inspection apparatus of FIG. 3 acquires both images at the same time as the conventional apparatus. However, since both the images are acquired with respect to one common inspection pattern, the detection unit is 1 There is only one. As described above, the pattern inspection apparatus of FIG. 3 generates the incident illumination image and the transmitted illumination image at the same time and performs the inspection using both images in the same manner as the pattern inspection apparatus of FIG. The inspection speed by is not inferior to the inspection speed by the pattern inspection apparatus of FIG.

  Further, the pattern inspection apparatus of FIG. 7 has an air dancer corresponding to each of the incident light inspection unit 31 and the transmitted light inspection unit 32 in order to give the tape 10 a slack and provide a function of smoothly transporting the tape 10. In contrast to the provision of 221 and 222, the pattern inspection apparatus of FIG. 3 has only one inspection section, and therefore only one air dancer is sufficient. As described above, the pattern inspection apparatus of FIG. 3 provides the functions of the incident light inspection unit 31, the transmitted light inspection unit 32, and the air dancers 221 and 222 in the pattern inspection apparatus of FIG. Therefore, the overall width is as small as 1690 mm. Therefore, the installation area of the apparatus of FIG. 5 is significantly reduced compared with the installation area of the apparatus of FIG. Furthermore, since the pattern inspection apparatus of FIG. 3 with one inspection section needs only one high-accuracy conveyance mechanism that intermittently conveys the tape 10 by a minute distance (a distance corresponding to the resolution of the cameras 5a and 5b). Compared with the conventional pattern inspection apparatus of FIG. 7 which requires two similar transport mechanisms, it can be manufactured at a much lower cost.

  In the pattern inspection apparatus of Patent Document 1, an epi-illumination device and a transmission illumination device are provided, and each of these illumination devices is assigned exclusively for epi-illumination image acquisition and transmission illumination image acquisition. When lit, both lights interfere with each other, and both images become completely unclear. Therefore, the lights are turned on alternately, and both images must be acquired alternately, and an improvement in inspection speed cannot be expected. On the other hand, the embodiment of the present invention described above illuminates one inspection pattern on the tape 10 with only one illumination device 4, so that an epi-illumination image and a transmission illumination image related to the inspection pattern are obtained. At the same time, it is possible to perform inspection using both the epi-illumination image and the transmission-illumination image on the pattern to be inspected at high speed, and based on only one of the epi-illumination image and the trans-illumination image. It can be installed in the same area as a pattern inspection apparatus for inspecting a pattern to be inspected, and the manufacturing cost is low.

  Although the embodiments have been described in detail above as specific examples of the present invention, the present invention is of course not limited to these embodiments. For example, in the embodiment of FIG. 1, there is only one incident light illumination image acquisition camera 1a, but in the pattern inspection apparatus of the present invention, a tape having a width wider than the visual field width of one camera is used. When inspecting, a configuration is adopted in which a plurality of epi-illumination image acquisition cameras are arranged side by side in the tape width direction so that an epi-illumination image is obtained for the entire tape width with the plurality of cameras. The same applies to the transmitted illumination image acquisition camera.

  Further, in the embodiment shown in FIGS. 1 to 3, there is only one illumination means (corresponding to the illumination device 4), but the present invention is not necessarily limited to one illumination means. For example, a first illumination unit for epi-illumination and a second illumination unit for transmission illumination are provided on the first imaging device (corresponding to the camera 5a) for epi-illumination image acquisition, and the first imaging device is The second imaging device (corresponding to the camera 5b) captures the strip-shaped workpiece with the illumination (transmission illumination) of the second illumination device, and images the strip-shaped workpiece with the illumination (epi-illumination) of the first illumination device. The present invention can also be implemented by adopting a configuration in which the optical axes of the first and second imaging devices are different, that is, the optical axes of the first and second imaging devices are offset.

  In such a configuration in which the first and second illumination units are provided and the optical axes of the first and second imaging devices are offset, the first and second imaging devices are each illuminated by only one illumination unit. Since the strip-shaped workpiece is imaged based on the above, the incident light and the transmitted light do not interfere with each other even if the incident illumination and the transmitted illumination are performed simultaneously. Therefore, the clear incident illumination image and the transmitted illumination image are captured in the first and second images. Since each of the first and second imaging devices can obtain images of the belt-like workpiece at the same time, the pattern to be inspected can be inspected at a high speed as in the case of the configuration having one illumination means. Further, in the pattern inspection apparatus having the first and second illumination units and having the optical axes of the first and second imaging devices offset, the pattern to be inspected in the strip-shaped workpiece is the first and second patterns. Although the first and second illuminating means and the first and second imaging devices can be installed in one inspection device, the belt-like workpiece conveyance mechanism is provided. Compared to the conventional pattern inspection apparatus of FIG. 7 which requires only one and two similar transport mechanisms, it can be manufactured at a much lower cost.

It is a conceptual diagram which shows the structure of one Embodiment of the pattern inspection apparatus which becomes this invention. It is a figure which shows the determination method of the quality of the to-be-inspected pattern by the control apparatus 1 in FIG. It is a block diagram for demonstrating the external dimension of the pattern inspection apparatus of FIG. It is a conceptual diagram which shows the principal part (A) of the pattern inspection apparatus which acquires only an epi-illumination image, and the principal part (B) of the pattern inspection apparatus which acquires only a transmitted illumination image. It is a figure explaining the epi-illumination image signal and transmitted illumination image signal by the pattern inspection apparatus of FIG. 4 (A) and (B). It is a conceptual diagram which shows the structure of the conventional pattern inspection apparatus. It is a block diagram which shows the conventional pattern inspection apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Control apparatus 1c, 1d Determination part 1e Compositing part 1f Final determination part 2 Tape conveyance mechanism 3 Tape pulling mechanism 4 Illumination apparatus 5a, 5b Camera 8 which uses CCD line sensor as light sensing means 8 Defective product punch mechanism 9
Master data 9a, 9b Reference pattern 10 Film carrier tape 10a for mounting electronic parts such as COF tape Unwinding reel 10b Rewinding reel 11 Control unit 11a Control unit main body 11b Display 11c Keyboard 21 Unwinding unit 21a, 23a Shafts 22,221 222 Air dancer 23 Winding part 25a, 25f Tension roller 25b, 25c, 25e, 25g Free sprocket 25d, 25h Sprocket 30 Inspection part 31 Incident light inspection part 32 Transmitted light inspection part 80 Puncher part 103, 104 Determination signal 105 Composite determination signal 200 Tape transport direction 501 Epi-illumination image signal 502 Transmission illumination image signal

Claims (3)

In a pattern inspection apparatus that images a pattern formed on a film-like strip workpiece and inspects the appearance of the pattern,
A first imaging means arranged on one surface side of the belt-like workpiece and imaging the belt-like workpiece;
A second imaging means disposed on the other surface side of the belt-like workpiece and imaging the belt-like workpiece;
A pattern inspection apparatus comprising: illumination means for irradiating from one surface side of the belt-like workpiece. The illumination unit includes an observation window that is disposed between the light incident opening of the first imaging unit and the strip-shaped workpiece, and transmits light reflected by the strip-shaped workpiece.
The pattern inspection apparatus according to claim 1, wherein the first imaging unit images the strip-shaped workpiece through the observation window.   The pattern inspection apparatus according to claim 1, wherein the illumination unit simultaneously performs illumination for the first imaging unit and illumination for the second imaging unit.

Images