JPH11233569A - Opening hole inspection device of base film tape for film carrier - Google Patents

Abstract

PROBLEM TO BE SOLVED: To readily carry out visual defect-inspection of an opening hole of a base film tape at a velocity corresponding to a processing speed by collecting an image signal of a tape having a hole opened in a base film tape and carrying out binarizing processing and labeling treatment. SOLUTION: An image signal of a hole opened in a base film tape 1 is collected, and in binarizing process, it is first converted to two kinds of values exceeding a threshold value and not exceeding a threshold value by a threshold value within an inspection frame which is set arbitrarily within image data picked by an image sensing device 5. In labeling treatment, continuous point within an inspection frame which is set in advance as for an arbitrarily preset value of either a value exceeding a threshold value or a value not exceeding a threshold value converted by binarizing process in one or a plurality of image data within inspection frame set arbitrarily in a collected image are regarded as one kind and made one count. Calculated hole area and the position of center of gravity of a hole, and the number of holes, etc., are compared to a specified set value and are judged acceptable or defective.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for inspecting an opening of a base film tape for a film carrier in a process of manufacturing a film carrier tape for a semiconductor IC. The present invention relates to an apparatus for inspecting a state of a laser hole. In addition, in addition to the holes formed in the entire TAB tape for LCD drivers and ASIC memories, the state of the holes formed in the flexible printed circuit board using materials and processes similar to those described above can be obtained. It is also used to inspect

[0002]

2. Description of the Related Art A tape for T-BGA (Tape-Ball Grid Array) is a film carrier tape for mounting semiconductor ICs, LSIs, and the like on a substrate. The wiring is made of a conductive material. The use of T-BGA is increasing because it can cope with more pins and narrower lead pitches than conventionally used TAB (Tape Automated Bonding) tape. T-BGA tape manufacturing process and materials can be converted to conventional TAB tape processes and materials, but the connection to the printed circuit board does not use OLB (outer lead bonding) like conventional TAB tape. The difference is that the connection using solder balls arranged in an array is used. For this reason, it can be assembled together with general parts and can be manufactured at low cost.
Further, since the connection portions are arranged two-dimensionally, the connection pitch can be increased as compared with the conventional connection method using OLB. That is, if the number of connections is the same, there is an advantage that a cheaper printed circuit board can be adopted. Conversely, when connections are made at the same pitch, it can be applied to LSIs with more pins, resulting in high value-added products.

[0003] Solder balls, which are a feature of the T-BGA, are arranged in a two-dimensional matrix at a pitch of 0.5 to 2.0 mm. The number of solder balls per BGA package needs to be a number corresponding to the number of leads (the number of pins) of the semiconductor IC to be mounted.

[0004] As a method of attaching the solder ball,
The mainstream method is to open holes corresponding to the number of solder balls in a solder resist (cover resist) film for insulating and protecting a conductive pattern such as a copper foil on a base film tape, and to attach the solder balls to the holes. in this way,
Although a hole pattern is formed in a necessary portion using a photosensitive resin such as an epoxy resin, there is a disadvantage that the process is complicated.

On the other hand, a method of forming an opening in the base film tape itself using a mold has been studied, and it is expected that the cost can be reduced by simplifying the process. When an opening is formed in a base film tape using a mold, a sheet-like adhesive (epoxy resin or the like) is laminated on one side of a resin film tape such as polyimide as a starting material, and PET (polyethylene terephthalate) is further formed. ) Use a protected base film such as a film. Holes for solder balls are opened in the base film tape by punching using a mold. The size of the holes is 100 to 800 μmΦ. These holes are formed in an area array per unit of base film tape (one piece).
Several tens to several hundreds are arranged.

[0006] These opening holes are defective in that the holes are not opened due to broken pins of the mold or the pins are deteriorated, the hole area is reduced due to the generation of burrs, and furthermore, a protective film remains inside the holes. May cause Such poor opening causes poor connection with solder balls,
Also, once degraded pins have a high probability of continuing failure in continuous processing of the base film tape. Therefore, it is necessary to accurately inspect all of these openings, and to promptly feed back to the machining process when a defect exceeding a certain limit occurs. Although the above description is directed to holes for solder balls, the same applies to holes of various shapes formed in TAB tape and FPC.

[0007]

Conventionally, the only means for inspecting these holes is visual inspection with the naked eye or visual inspection with a microscope. However, in the visual inspection with the naked eye, as the hole diameter becomes smaller, it becomes difficult to confirm the presence or absence of the opening relatively easily. It is more difficult to confirm the residual in the hole of the protective film because the target is transparent. In many cases, burrs have a size of the order of 10 μm, which is completely impossible. In the visual inspection using a microscope, the above-mentioned problem with the naked eye can be solved by increasing the magnification. However, the speed of the visual inspection using a microscope is much slower than the speed of opening a mold. Therefore, in order to apply mass inspection using a microscope to mass production, it is necessary to secure many visual inspection personnel, which is against price reduction. Further, the arrangement of the holes is not always regular. In the case of a motif in which holes are irregularly arranged and there is a base without holes, recognition may occur even if some holes are not opened. Further, it is a serious problem that visual inspections cannot avoid failures due to fatigue or misunderstanding.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an appearance inspection apparatus which can easily and automatically inspect appearance defects of opening holes of a base film tape at a speed corresponding to a processing speed in a process of manufacturing a film carrier tape for a semiconductor IC. To provide.

[0009]

Means for Solving the Problems The present inventors have conducted various studies to solve the above-mentioned problems, and as a result, the conventional visual inspection by the naked eye has been carried out on a base film tape for a film carrier using a base film tape inspection apparatus. By providing means for sampling the image signal of the tape including the opened holes and performing binarization processing and labeling processing, the appearance defect inspection of the opening holes of the base film tape can be easily performed at a speed corresponding to the processing speed. Has completed this visual inspection system.

That is, the present invention provides an apparatus for inspecting an opening of a base film tape for a film carrier, comprising means for collecting an image signal of a tape including an opening formed in the base film tape, and performing binarization processing and labeling processing. The above-described opening hole inspection apparatus is characterized in that:

[0011]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. FIG. 1 is a block diagram showing the overall configuration of an embodiment of the inspection apparatus of the present invention. In FIG. 1, reference numeral 1 denotes a base film tape to be inspected. Reference numeral 2 denotes a delivery device in which the tape is wound on a reel. Numeral 3 detects and counts perforation holes (sprocket holes) formed at the end in the width direction of the tape for positioning the reference hole of the apparatus and the opening hole pattern of the base film tape, and positions the base film tape. This is a position information generation device that generates information. Reference numeral 4 denotes an illuminating device for irradiating parallel light having a uniform surface luminance to an opening hole pattern portion of a base film tape to be inspected and collecting an image by the transmitted light. Reference numeral 5 denotes an imaging device for collecting an image using the transmitted light. 6 is 2 for the collected image data
This is an image processing device that performs a binarization process and a labeling process.
Reference numeral 7 denotes a control device for collecting a signal from the perforation hole detection device 3 and collecting an image when the opening hole pattern is conveyed to a predetermined position. Reference numeral 8 denotes a marking device for marking an identification mark in one unit of the base film tape determined to have an opening defect by the image processing device 6. Reference numeral 9 denotes a winding device for winding the base film tape.

According to the opening hole inspection apparatus of the present invention, the opening hole inspection apparatus for the base film tape for a film carrier has means for collecting an image signal of the hole opened in the base film tape, and performing binarization processing and labeling processing. The opening hole inspection apparatus includes a driving unit for driving and driving the base film tape wound on a reel, and detecting a perforation hole of the base film tape conveyed by the driving unit. Position information generating means for counting and counting, and generating relative position information with respect to a reference position of the opening hole pattern, and an image for collecting an image of the opening hole pattern of the base film tape at a predetermined interval from the position information generating means. Collection means, uniform in the opening hole of the base film tape from the surface opposite to the image collection. Illuminating means for illuminating line light; discriminating processing means for processing the image data to determine an opening defect; and the base disposed along a transport path of the base film at a predetermined distance from the image capturing position. Marking means for making an identification mark on the film tape, and winding means for winding the base film tape around a reel are provided.

In the inspection apparatus of the present invention, the base film tape transport driving means and the base film tape winding means may use the conventional transport driving means and tape winding means used in a continuous processing apparatus for TAB tape or the like. it can. Tape unwinding and take-up reel
The rotation speed of the base film tape is controlled by the control device so that the transport speed of the base film tape is always constant as set. As a result, the base film tape moves at a constant speed set in the right direction in the figure.

As the base film tape, in addition to predetermined perforation holes (sprocket holes), holes having a hole diameter of 50 to 5000 microns are provided.
10 to 1500 pieces per unit, pitch 0.5 to 3.0 m
It is possible to inspect what is open at m. Position information generating means for detecting this perforation hole,
A light beam is applied to the end of the base film tape in the width direction using an illuminating device, and light transmitted through the perforation hole of the light beam is detected by a light receiving element, and the signal is sent to the control device. The control device counts the number of times of the transmitted light, and collects an image of the opening hole pattern for each of the predetermined number of perforation holes corresponding to the predetermined number of perforation holes corresponding to one unit of the base film tape. As the illuminating device, a flat light source such as a cold cathode tube can be used.

As the image taking device, a CCD camera or the like is used. The image processing apparatus calculates the hole area, the center of gravity of the holes, and the number of holes after binarizing and labeling the collected image signals. In the binarization process, first, a value (for example, white on a display image) that is equal to or larger than a threshold value within an arbitrarily set detection frame in image data collected from a CCD camera is set according to an arbitrarily set threshold value. The value is converted into two values below a threshold value (for example, black on a display image).

In the labeling process, of the image data in one or a plurality of detection frames arbitrarily set in the sampled image, a value equal to or greater than the threshold value converted by the above-described binarization process or equal to or less than the threshold value. Regarding one of the values arbitrarily selected, a continuous point within the previously set detection frame is regarded as one type and is regarded as one count. The calculated hole area, the center of gravity of the hole, the number of holes, and the like are compared with predetermined set values, or compared with a reference image input in advance to determine good or bad. If the fragments of the protective film remain in the openings, the light from the illumination device is transmitted, but the light intensity, which is the reference when binarizing the image signal collected by the image processing device, is set appropriately. By doing so, it becomes possible to detect.

The above inspection result by the image processing apparatus is C
At the same time as being sent to an output device such as an RT, it is recorded in an external storage device such as a floppy disk.

The marking device is installed along the transport path of the base film tape and at a position separated by a predetermined distance from the position information generating means, within a unit of the base film tape determined to have an opening defect by the image processing device 6. For example, an identification mark which can be visually read by a marking means such as stamping, punching, printing, laser marking, or the like or quickly read by an image recognition device is provided. After the end of the series of inspection operations, the next unit of the base film tape being conveyed at a constant speed is repeated according to the above flow to continue the inspection.

Further, the aperture inspection apparatus of the present invention may further include a signal generating means for generating a corresponding signal when it is determined necessary by the determination processing. For example,
When the number of defectives continuously exceeds the predetermined value, a signal is sent to the control device, and the control device sends a signal to the base film tape transport driving device and the winding device to stop, or a warning. It emits a buzzer or the like.

According to the opening hole inspection apparatus of the present invention, it is possible to cope with base film tapes having various widths.
The inspection speed varies depending on the width of the base film tape, the number of perforations, and the number of openings per unit of the base film tape. In the case of a product having a base film tape width of 35 mm and five perforations, the number of holes is more than ten to several hundreds. It can be inspected individually at a speed of about 300 to 330 msec / piece.

The inspection speed depends on the ability of the apparatus to perform image signal sampling, image data processing, pass / fail judgment processing, and the like. Thus, by changing to a device with improved throughput, the speed of the inspection according to the invention will automatically be improved.

FIG. 2 is a flowchart for explaining the operation of the embodiment of the present invention. First, in the opening inspection apparatus of the present invention, the number of perforations of the base film tape is set. Next, the transport speed of the base film tape is set, and the transport of the base film tape is started.
The perforation holes in the conveyed base film tape are detected and counted, and the position information is sent to the control unit. Next, the illumination device and the imaging device are activated based on the signal from the control unit, and an image is collected by the transmitted light from the aperture pattern portion. 2 in the obtained image data
A value process and a labeling process are performed, and the quality of the opening is inspected.

If it is determined that there is a predetermined opening defect, a marker positioning counter is activated, the result is output and the result is displayed on a CRT, and a marking device is activated to place the marker in one unit of the base film tape. Attach an identification mark.

On the other hand, if it is determined that the aperture is good, the result is output and the result is displayed on a CRT. Since then
The inspection is continued by repeating these series of operations for the next transported base film tape.

Using the above-described opening hole inspection apparatus of the present invention, the results of repeatedly inspecting three types of base film opening holes for solder balls having different numbers and arrangements of opening holes at a conveying speed of 5 m / min. Are shown in Table 1. Table 1 also shows the results of visual inspection using a microscope. The numbers in the table are the number of detected defects. The results of the aperture inspection apparatus of the present invention are stable in any of the three types of motifs.

On the other hand, in the visual inspection using a microscope, although the learning effect by repetition is recognized as compared with the opening inspection apparatus of the present invention, the number of detections is small and it is not stable. That is, the visual inspection indicates that there is an oversight of a defect. The time required for the inspection of the motif 1 is about 20 hours or more for the visual inspection, and the opening inspection apparatus of the present invention is greatly reduced to about 32 minutes.

[0027]

[Table 1]

[0028]

As described above, according to the present invention, a visual inspection apparatus capable of easily and automatically detecting various opening defects generated in an opening formed by a mold or a laser at a speed corresponding to a processing speed. Can be provided. Therefore, the present apparatus can be incorporated into a production line of a film carrier tape for a semiconductor IC such as a T-BGA to reduce the cost of a film carrier having a large number of opening hole patterns.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an overall configuration of an embodiment of a visual inspection apparatus according to the present invention.

FIG. 2 is a flowchart illustrating the operation of an embodiment of the present invention.

[Explanation of symbols]

1: base film tape, 2: sending device, 3: position information generating device, 4: lighting device, 5: imaging device, 6: image processing unit, 7: control unit, 8: marking device,
9: Winding device.

Claims (3)

[Claims] 1. An apparatus for inspecting an opening of a base film tape for a film carrier, comprising: means for collecting an image signal of a tape including an opening formed in the base film tape, and performing binarization processing and labeling processing. The opening hole inspection apparatus described above. 2. A driving means for conveying and driving the base film tape wound on a reel; detecting and counting perforation holes of the base film tape conveyed by the driving means; Position information generating means for generating relative position information with respect to a position; image collecting means for collecting an image of the opening hole pattern of the base film tape at a predetermined interval from the position information generating means; and opening of the base film tape Illuminating means for irradiating uniform parallel light to the hole from the side opposite to the image capturing; determining processing means for processing the image data to determine an aperture defect; and Marking means disposed along the transport path of the base film tape, and marking means for making an identification mark on the base film tape, 2. The apparatus according to claim 1, further comprising a winding unit configured to wind the base film tape around a reel. 3. The aperture inspection apparatus according to claim 1, further comprising a signal generation unit that generates a corresponding signal when it is determined that the signal is necessary by the determination process.