JP2009115532A - Pattern inspecting apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pattern inspecting apparatus capable of correcting the curvature of a tape carrier for the mounting of electronic components in the direction of the width, without having to provide a large-scale drive mechanism or imaging wiring patterns by reflected light, as well as, wiring patterns by transmitted light. <P>SOLUTION: The pattern inspecting apparatus for optically acquiring and inspecting the shape of wiring patterns formed in the tape carrier for the mounting of electronic components is provided with a drum body 8 that holds the tape carrier 5 in a curved state and sequentially arranging the wiring patterns formed in the tape carrier 5 in an imaging region of a line sensor. An illumination means 14 is provided for the inside of the drum body 8. The light emitted from the illumination means 14 and transmitted through the tape carrier 5 is imaged by the line sensor arranged outside the drum body 8. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an inspection device for a wiring pattern formed on a tape carrier used in, for example, a TAB (Tape Automated Bonding) method, and more particularly to a pattern inspection device for optically inspecting the shape of a wiring pattern.

  2. Description of the Related Art Conventionally, integrated circuit production methods such as TCP (Tape Carrier Package) and COF (Chip On Film), in which an IC chip is mounted on a long tape based on a resin film and external terminals are provided, have been widely used. Yes. This tape is referred to as a tape carrier, and generally, the following process is performed to manufacture such a tape carrier.

First, after punching, for example, a polyimide film serving as an insulating base material into a desired shape, a copper foil is attached via an adhesive. Next, a photoresist is coated on the copper foil, exposed and developed using a photomask, and a wiring pattern is formed by etching. And in order to protect between wiring and wiring, a soldering resist is printed except for the part used as a connection terminal among wiring patterns. Next, after the solder resist is dried and cured, a desired plating process such as tin plating or gold plating is performed on the exposed connection terminal portion.

  After such a process, the IC chip is mounted on the tape carrier. Whether or not the wiring pattern is formed in a desired shape before the mounting and after the wiring pattern is formed. Must be inspected for all pieces (a piece is a unit of a wiring pattern area used for one final product). There are various forms of wiring pattern defects such as disconnection, short circuit, defect, protrusion, scatter, pinhole, etc. Other narrow pattern width that does not lead to complete disconnection, and wide pattern width that does not result in complete short circuit Therefore, optical inspection means that can comprehensively inspect these conditions are being widely adopted.

  The inspection method using optical means acquires an image of a wiring pattern formed on a tape carrier to be inspected, and this image and a good pattern image stored in advance or CAD data of the wiring pattern. Is generally determined by image processing means. In addition, in order to obtain a high-definition inspection target image, a line sensor in which imaging elements are arranged in a row is used, and the inspection target piece on the tape carrier is transported in the tape carrier or in a direction perpendicular to the transport direction. Many methods of scanning and acquiring images are employed. Then, when the line pattern is imaged by the line sensor, a method of performing imaging while supporting the surface of the tape carrier to be flat, and a method of imaging while supporting the surface of the tape carrier to be curved in the transport direction. There is a way to do it.

  The tape carrier on which the wiring pattern is formed is formed by adhering a resin layer such as a polyimide film as the base material and a metal layer such as copper as the wiring pattern. Therefore, warpage usually occurs in the width direction of the tape carrier. This warpage gives an unintentional change in the distance between the line sensor and the inspection object, and a device that enables the camera incorporating the line sensor and the entire area of the inspection object to be imaged at the same distance as much as possible. Necessary. Therefore, in order to support the surface of the tape carrier to be imaged on a flat surface, Patent Document 1 discloses means for mechanically gripping the perforation areas at both ends of the tape in the width direction and pulling the tape in the width direction. .

  Further, even if the tape carrier is curved in the tape transport direction, warpage in the tape width direction can be suppressed, so in Patent Document 2, as shown in FIG. 6, the upper side of the curved side surface of the inspection drum 51 The tape carrier is conveyed along the line. Here, a conventional technique will be described with reference to FIG. 6A is a front view of a conventional pattern inspection apparatus, and FIG. 6B is a view of the inspection target viewed from the direction of the camera 52 in FIG. 6A. In FIG. 6A, reference numeral 53 denotes an unwinding portion, 54 denotes an inspection portion, and 55 denotes a winding portion. Then, the tape carrier 56 to be inspected is unwound from the unwinding reel 57 attached to the unwinding portion 53 and is stored in the take-up reel 58 attached to the take-up portion 55 after passing through the inspection portion 54.

  The inspection carrier 54 transports the tape carrier 56 by guide rollers 59 and 59 ', tension rollers 60 and 60', and an inspection drum 51. The tension rollers 60 and 60 'are supported by a vertically movable shaft, An appropriate tension is applied to the tape carrier 56 on the inspection drum 51 by pressing the tape carrier 56 downward with a load. Reference numeral 50 denotes ring-type illumination, which irradiates diffused light onto the inspection target on the inspection drum, and the camera 52 captures the reflected light to obtain an image of the wiring pattern formed on the inspection target piece.

  FIG. 6B is a view of the inspection target as viewed from above, and shows a state in which the inspection drum 51 is rotatably supported around the shaft 61. Here, 62 and 62 ′ are bearings that rotatably support the shaft 61, and 63 is a motor that applies a rotational force to the shaft 61. Then, the take-up reel 57 and the take-up reel 58 rotate in synchronization with the rotation of the inspection drum 51, and the camera 52 images the inspection target piece on the tape surface in a cycle of a pixel unit in synchronization with the moving distance of the tape carrier. To do. This is a line-shaped region captured by the camera 52 to which the line indicated by reference numeral 64 is fixed.

  6 shows a case where the imaging area (length of the imaging line) of the line sensor provided in one camera 52 can cover the entire width of the inspection target piece as indicated by the line 64. The line length of a line sensor with a large number of image sensors corresponding to fine pixels is limited in terms of distribution to the market. On the other hand, the width of the tape carrier to be inspected is increasingly moving in the expanding direction. is doing. Therefore, a method as shown in FIG. In FIG. 7 (a), two cameras indicated by reference numerals 65 and 65 'and illuminations 66 and 66' corresponding to the cameras are provided in the inspection section with a relative inclination angle. Since the elements are the same as those in FIG. 10A, detailed description with reference numerals is omitted.

  Here, the two cameras are provided with a relatively inclined angle, and at the same time, the two cameras are shifted in the front-rear direction as seen in FIG. In b), the line indicated by reference numeral 67 is the imaging area, and the camera 65 'is the imaging area indicated by reference numeral 67' in the figure, and the inspection area is shared in the width direction of the carrier tape by each camera. I have to. Although this example has been described using two cameras, it is possible to use a larger number of cameras.

Japanese Patent Laying-Open No. 2004-28597 (page 4, FIG. 5) Japanese Patent Laying-Open No. 2005-3645 (page 3, FIG. 1)

  Considering the prior art described so far, as in Patent Document 1, when the tape carrier in the region to be imaged is supported on a flat surface, the scanning direction by the line sensor may be performed in the tape transport direction. It is also possible to perform in the width direction of the tape. A camera and illumination are arranged on one side of the tape to acquire an image by reflected light. A camera is arranged on one side of the tape and the other side is arranged. It is also possible to obtain an image by transmitted light by arranging illumination on the surface side.

  On the other hand, if a method that requires a large drive system in addition to transporting the tape, that is, scanning while accurately moving the camera and illumination in the width direction of the tape, was a conventional problem. In order to correct the warp in the width direction of the carrier tape, the method using the inspection drum according to Patent Document 2 described with reference to FIGS. 6 and 7 is very advantageous in reducing the cost of the inspection apparatus. is there. However, the method using the inspection drum has the above-mentioned merit for imaging using reflected light, but imaging using transmitted light is difficult, and provides an imaging method suitable for various types of inspection objects. There was a problem in that.

As a first aspect of the present invention, in a pattern inspection apparatus for optically acquiring and inspecting the shape of a wiring pattern formed on a tape carrier for mounting electronic components, the tape carrier is held in a curved state, and the tape carrier A drum body is provided for successively arranging the wiring patterns formed in the imaging region of the line sensor, and further provided with illumination means inside the drum body, so that the illumination means emits light transmitted through the tape carrier. Provides a pattern inspection apparatus in which an image is picked up by the line sensor arranged outside the drum body.

According to a second aspect of the present invention, the drum body is in contact with the vicinity of both ends in the width direction of the tape carrier and rotates with the conveyance of the tape carrier, and the inside of the pair of rotation disks. A pair of fixed plates having a disk shape within at least an arcuate angular range in which the pair of rotating disks contact the tape carrier, and a pair of fixed plates that are rotatably supported and conveyed. A plurality of rotary rollers that are in rolling contact with the back surface of the inspection area of the tape carrier and a gap between the pair of fixed plates, and emit light from the gap between the plurality of rotary rollers toward the outside of the drum body. The pattern inspection apparatus according to the first aspect, characterized in that the pattern inspection apparatus is configured with illumination means.

Furthermore, as a third aspect of the present invention, the pair of fixing plates provided on the drum body includes:
The partition wall is erected in a portion other than the arcuate angular range, and the partition wall separates the space on the gap side of the pair of fixing plates and the space outside thereof, and the pair of fixed plates The pattern inspection apparatus according to the second aspect is provided with an ejection port for ejecting a gas drawn from the outside of the drum body in the space of the gap.

  According to the first aspect of the present invention, since the tape carrier located in the imaging range of the line sensor is curved in the transport direction using the drum body, the tape width direction can be obtained without providing a large drive mechanism. Warp can be corrected. Further, the illumination means is provided inside the drum body, and the transmitted light that has passed through the tape carrier can be imaged by the line sensor. Moreover, in addition to the line sensor provided outside the drum body, the illumination means is provided outside the drum body as in the past, so that imaging by reflected light and transmission light are performed according to the type of inspection object and the inspection method. It becomes possible to select imaging. Furthermore, by reciprocating the tape carrier, it is possible to acquire both imaging results of reflected light and transmitted light for the same inspection object.

  Further, according to the second aspect of the present invention, the vicinity of both ends in the width direction of the tape carrier is supported in an arc shape in the tape transport direction by using a pair of rotating disks, and the other portion (the central portion in the width direction of the tape) The vicinity) can be supported in a substantially arc shape in the tape transport direction using a plurality of rotating rollers. Therefore, the tape carrier can be held curved as a whole in the tape transport direction. Further, with such a structure, the light emitted from the illumination means provided inside can be emitted to the outside of the drum body through the gap between the rotating rollers.

  Further, according to the third aspect of the present invention, even if the tape carrier is thin and wide in the width direction, the gas drawn from the outside of the drum body is blown out in the space between the pair of fixed plates, and the internal pressure is reduced. Therefore, pressure can be applied from the inside of the curve to the tape carrier located in the gap between the plurality of rotating rollers supported between the pair of fixed plates. Therefore, the tape carrier positioned in the gap between the rotating rollers including the imaging position by the line sensor can be held as a whole curved in the tape transport direction without being dented inwardly of the curve.

  Next, an embodiment of a pattern inspection apparatus according to the present invention will be described in detail with reference to the accompanying drawings.

  First, the overall configuration of the pattern inspection apparatus according to the present invention will be described with reference to FIG. In FIG. 1, reference numeral 1 denotes an unwinding part, 2 denotes an inspection part, and 3 denotes a winding part. The overall configuration includes a control unit that controls the operation of the entire apparatus, an image processing unit that derives an inspection result from the acquired image, an inspection operation unit, and a display unit that displays the inspection result, but the illustration is omitted here. . Further, FIG. 1 shows a minimum necessary configuration. In an actual inspection line, a piece that is a defect candidate in the inspection unit 2 is enlarged by a microscope between the inspection unit 2 and the winding unit 3 and re-used. There may be a case where a microscope verifying section to be confirmed, a marking section for performing marking indicating a defect on a piece determined to be a defective piece, or the like is provided.

  First, from the left of the figure, the unwinding reel 4 is mounted on the unwinding portion 1, and the unexamined tape carrier 5 is stored in the unwinding reel 4. The tape carrier 5 is conveyed to the inspection unit 2 with the wiring pattern surface facing upward as seen in the figure. The tape carrier 5 conveyed to the inspection unit 2 passes through the upper part of the guide roller 6 that is rotatably supported, and then passes through the lower part of the tension roller 7. The tension roller 7 is supported by a vertically movable shaft, and presses the tape carrier 5 downward with a predetermined load, so that the tension roller 7 is moderately applied to the tape carrier 5 passing through the upper portion of the drum body 8 together with another tension roller 7 ′. Tension is applied. The tape carrier 5 passing through the upper part of the drum body 8 and passing through the lower part of the tension roller 7 ′ is taken up and stored on the take-up reel 9 mounted on the take-up unit 3.

  Reference numeral 10 denotes a camera, which includes a line sensor in which image pickup elements are arranged in a line in the width direction of the tape carrier 5. The imaging lens is directed to the tape carrier 5 that is curved and held at the upper part of the drum body, and is focused on the wiring pattern that is the imaging target. Here, a ring-shaped illuminating means drawn with a one-dot chain line and attached with a reference numeral 11 is not only used for photographing transmitted light but also reflected by using the illuminating means housed in the drum body 8 according to the present invention. It is provided in consideration of the case where light is also taken. Although only one camera 10 is depicted in FIG. 1, as described in the prior art based on FIG. 7, in order to accommodate a wide tape carrier, the imaging lens is directed toward the rotation axis of the drum body. Multiple cameras can be provided.

  Next, the structure of the drum body 8 will be described with reference to FIG. FIG. 2 is a front view of the drum body 8 shown in FIG. 1 as viewed from the same direction, and shows a state where the tape carrier 5 is in contact with the upper part of the drum body 8 and is curved. In the case of the present embodiment, the tape carrier 5 is in contact with the arc portion having a central angle of 180 degrees, which is the upper half of the drum body 8, but this is not limited to 180 degrees and may be increased or decreased. Further, the front rotating disk 12 seen in the front is paired with a rotating disk on the back side (not shown), and six rotating rollers 13 drawn by dotted lines hidden behind the rotating disk 12 are inspected of the tape carrier 5. It is supported to rotate freely while rolling on the back of the range. In addition, the illumination means 14 which is also drawn with a dotted line emits diffused light upward from the inside of the drum body 8.

  A bearing 16 is erected on the base 15, and a driving shaft 17 is rotatably supported on the bearing 16 and a cylindrical projection 18 </ b> A of a fixed plate is fixed. A timing belt 21 is suspended between a first timing pulley 19 fixed to the front rotating disk 12 and a second timing pulley 20 fixed to the drive shaft 17.

  Next, the structure of the drum body 8 will be described with reference to FIG. FIG. 3 is a side view illustrating the right side surface of the drum body 8, and the left side is the front side and the right side is the back side. Paired with the above-described rotating disk 12 is another rotating disk 12 'disposed on the back side, and ring-shaped projections 12A and 12A' are erected with a slight step on the outer periphery. Has been. Further, a pair of fixing plates 18 and 18 'are provided so as to be hidden inside the projections 12A and 12A'. The cylindrical projection 18A provided on one fixing plate 18 is provided on the bearing 16 and the other fixing plate 18 '. The cylindrical protrusions 18A 'provided on the are fixed to the bearings 16'.

  The pair of rotating disks 12 and 12 'are rotatably mounted on the cylindrical projections 18 and 18' provided on the pair of fixed plates, respectively, and are connected to the first timing pulley 19 'and the rear side of the first timing pulley 19'. A timing belt 21 'is also suspended from the second timing pulley 20'. Accordingly, when the motor 22 is driven and the drive shaft 17 rotates, the pair of rotating disks 12 and 12 'rotate at the same angle in the same direction. The pair of fixed plates 18 and 18 ′ that remain stationary even when the pair of rotating disks 12 and 12 ′ are rotated support the six rotating rollers 13 rotatably at the upper part of the mutual gaps. In the other lower part, partition walls 18B and 18B 'standing in the direction of each other are provided on the outer periphery, and the tips of both outer walls are in contact with each other.

  Next, the structure of the drum body 8 will be further described with reference to FIG. FIG. 4A is a diagram in which illustration of the rotating disk 12, the fixed plate 18, and the drive system member on the front side is omitted so that the inside of the drum body 8 can be easily seen when viewed from the front. In FIG. 4 (a), a ring-shaped protrusion 12A 'is erected on the rotating disk 12' on the back side, and its outer peripheral surface coincides with the surface of the rotating roller 13 at the portion indicated by reference numeral (a). Yes. Accordingly, the outer peripheral surface of the ring-shaped protrusion 12A ′ contacts and rotates in the perforation areas at both ends in the width direction of the tape carrier 5 to be transported, and the portion other than the vicinity of both ends in the width direction of the tape carrier 5, that is, the inspection target region The rotating roller 13 is in rolling contact with the back surface of the roller.

  The illumination means 14 is disposed on the front side of the fixed plate 18 'on the back side, that is, in the gap between the pair of fixed plates 18 and 18'. Here, reference numeral 14A denotes a cylindrical light source lamp, 14B denotes a reflector, and 14C denotes a diffusing lens that returns light having strong directivity emitted from the light source lamp 14A to diffused light. In this embodiment, the power cable 14D for light emission of the lamp is drawn from the hole of the cylindrical projection 18A 'provided on the fixed plate 18'. The light guide, which is a bundle of optical fibers, is drawn from this hole to the drum. If a light emitting part is provided inside the body 8, the light source device can be provided outside the drum body 8.

  FIG. 4B is a view of the cross section Ei shown in FIG. However, in this cross-sectional view, the rotating disc 12 and the fixed plate 18 on the front side, which are not shown in FIG. Here, reference numeral 23 denotes a nozzle that is continuously provided in a hole of a cylindrical protrusion 18A provided on the front-side fixing plate 18, one end facing the continuous portion is closed, and a plurality of jets 23A are provided on a side surface. . And gas is inject | poured from the opening part of the said cylindrical protrusion 18A, and it makes it eject from 23A of jet nozzles. Since the lower portion of the drum body 8 is covered with partition walls 18B and 18B 'standing on a pair of fixing plates 18 and 18', when the internal pressure increases, pressure is applied to the inner surface of the curved tape carrier 5.

  Even if the tape carrier 5 is thin and wide, the above-described action is exerted. Therefore, the tape carrier 5 is not locally deformed, and a state of being straightly bent in the tape transport direction can be created. In the present embodiment, the pair of fixed plates have a perfect disc shape, and the partition walls 18B and 18B 'have an arc shape along the outer periphery thereof, but an arc-shaped angular range in which the rotating roller 13 is disposed. The other portions do not need to have a disk shape, and the same effect can be obtained with the shape as shown in FIG. 5 drawn corresponding to FIG. Furthermore, in the present embodiment, it has been described that gas is injected from the front side of the drum body 8 and a power source or light guide for illumination means is introduced from the back side. 18B and 18B ′ may be provided with introduction ports, which may be drawn into the drum body 8.

Front view showing an embodiment of the present invention The principal part front view which shows embodiment of this invention The principal part side view which shows embodiment of this invention Front view and sectional view showing an embodiment of the present invention Front view showing an embodiment of the present invention Front view and detailed view showing conventional technology Front view and detailed view showing conventional technology

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Unwinding part 2 Inspection | inspection part 3 Winding part 4 Unwinding reel 5 Tape carrier 6, 6 'Guide roller 7, 7' Tension roller 8 Drum body 9 Take-up reel 10 Camera 11 Ring-shaped illumination means 12, 12 'Rotating circle Plate 13 Rotating roller 14 Illuminating means 15 Base 16, 16 ′ Bearing 17 Drive shaft 18, 18 ′ Fixed plate 19, 19 ′ First timing pulley 20, 20 ′ Second timing pulley 21, 21 ′ Timing belt 22 Motor 23 nozzle

Claims (3)

In a pattern inspection device that optically acquires and inspects the shape of a wiring pattern formed on a tape carrier for mounting electronic components, the tape carrier is held in a curved state, and the wiring pattern formed on the tape carrier is line sensor The drum body arranged one after another is provided in the imaging region, and further provided with illumination means inside the drum body, the light emitted from the illumination means and transmitted through the tape carrier is arranged outside the drum body. The pattern inspection apparatus is picked up by the line sensor. The drum body is provided inside a pair of rotating disks that are in contact with the vicinity of both ends in the width direction of the tape carrier and rotates with the conveyance of the tape carrier, and at least the pair of rotating disks. A pair of fixed plates having a disk shape within an arcuate angular range where the plate contacts the tape carrier, and the back surface of the inspection area of the tape carrier that is rotatably supported and conveyed between the pair of fixed plates A plurality of rotating rollers that are in rolling contact with each other, and an illumination unit that is provided in a gap between the pair of fixed plates and emits light toward the outside of the drum body from the gap between the plurality of rotating rollers. The pattern inspection apparatus according to claim 1. The pair of fixing plates provided on the drum body has a partition wall erected at a portion other than the arc-shaped angular range, and the partition wall is formed between the space on the gap side of the pair of fixing plates and the outside thereof. The pattern inspection according to claim 2, wherein the space is separated from the space, and the space between the pair of fixed plates includes a spout for ejecting a gas drawn from the outside of the drum body. apparatus.

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