JP4013302B2 - Inspection method of carrier tape - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention accommodates a large number of various electronic components, and stores, conveys, and inspects the pitch of the sprocket holes of the carrier tape and the dimensions between the sprocket holes and the recesses, which are useful for smooth operation with a surface mounter. Regarding the method.
[0002]
[Prior art]
Conventional sprocket hole pitch (hereinafter referred to as H dimension, standard = 4.00 ± 0.10 mm) defect inspection method involves winding a product around a cylindrical roll (hereinafter referred to as pin roll) having a large number of pins. This was done by measuring the amount of product lift caused by entwining a pin with a sprocket hole.
[0003]
[Problems to be solved by the invention]
In recent years, with the increase in mounting speed of surface mounters, higher accuracy than ever is required for the H dimension. That is, at present, in the surface mounting machine, the part removal from the carrier tape is stopped by moving the carrier tape whose position is controlled by the rotation of the gear inserted into the sprocket hole every time, moving it to a predetermined position, and stopping it. After that, the component is picked up by the movable arm and transferred (mounted) to the mounting position on the substrate.
[0004]
For this reason, this misalignment at the time of component pick-up causes a component drop due to a pick-up mistake or a position shift at the time of mounting. The positioning accuracy is naturally proportional to the mounting speed, and higher accuracy is required as the speed increases. As a result, the sprocket hole that determines the moving position of the parts is required to have higher accuracy than before.
[0005]
However, in the above conventional defect inspection method, the pin diameter of the pin roll must be designed smaller than the sprocket hole in order to smoothly entangle the sprocket hole of the carrier tape, and the diameter of the sprocket hole (hereinafter referred to as the sprocket hole diameter). That is, it is necessary to have a diameter of 1.30 mm or less with respect to 1.55 mm, resulting in a clearance of 0.25 mm or more, and it is difficult to set the inspection accuracy to the current level ± 0.3 mm or more.
In addition, in this conventional inspection method, the pins of the pin roll are inserted into the sprocket holes as needed, so that dust, burrs, etc. are likely to adhere to the pin part, which causes the amount of product lift to change, resulting in malfunction. Cheap.
[0006]
Furthermore, in the carrier tape manufactured by the press molding method, the concave portion is formed and the sprocket hole and the concave bottom hole are punched in the same mold, so the positional relationship between the sprocket hole and the concave portion is always kept constant. In the H dimension inspection, the dimension between the center of the sprocket hole and the center of the recess (hereinafter referred to as G dimension. Standard: product width 16 mm or less = 2.00 ± 0.05 / product width 16 mm or more = 2.00 ± 0.10) However, the carrier tape manufacturing method (vacuum forming method and pressure forming method) in which the forming of the recesses and the punching of the sprocket holes and the bottom holes of the recesses are performed with different molds is performed due to its mechanism. Since there is no correlation between the H dimension and the G dimension, only the H dimension inspection using a conventional sprocket hole could not be used for the G dimension inspection.
[0007]
In recent years, a method based on image processing has attracted attention as a method for realizing an all-in-line dimension inspection system for high-speed press lines, but there are problems in high-speed followability, required accuracy, and inspection environment.
That is, many image processing apparatuses that are currently available on the market can perform an area detection of about 60 times per second, whereas the position detection is about 30 times per second even with a high-speed position detection. When inspecting all the G dimensions in-line, the processing speed is limited to a maximum of 4 mm x 30 times x 60 seconds = 7.2 m / min, and is compatible with production lines with speeds exceeding 10 m / min. Can not.
[0008]
Further, it is said that the guaranteed value of position detection accuracy of a CCD image sensor as an image sensor is usually less than ± 2 pixels. When detecting 4.00 mm in units of 1/100 mm, at least 800 pixels ( 2 pixels: 1/100 mm), and a general CCD camera (number of inspectable pixels: 512 × 480 pixels) cannot be detected with high accuracy because of its structure. In addition, the shift of the captured image due to the vibration of the press machine is a major cause of erroneous detection when performing position detection.
[0009]
Therefore, the object of the present invention is to simultaneously perform the inspection of the H dimension and the G dimension when forming the concave portion of the carrier tape and punching the sprocket hole and the concave portion bottom hole by the vacuum forming method and the pressure forming method. It is an object of the present invention to provide a carrier tape inspection method that can easily and accurately detect a defect inspection by an image processing apparatus.
[0010]
[Means for Solving the Problems]
In the carrier tape inspection method of the present invention, by inserting a pilot pin having the same shape as the inside of the recessed portion of the positioned carrier tape into the recessed portion, the area of the whitened portion due to the deformation generated in the peripheral portion of the recessed portion is subjected to image processing. By detecting with the apparatus and comparing and determining the value with the specified value, the defect detection of the H dimension and the G dimension is simultaneously performed.
[0011]
The pilot pin used in the inspection method of the present invention is used by changing the shape and size according to the material of the raw material of the carrier tape, the thickness, the shape of the recess, the H dimension and the G dimension standard, It is preferably the same shape as the inside of the concave portion of the carrier tape to be applied, 0.00mm to 0.05mm smaller than the actual dimension inside the concave portion, and the tip portion subjected to R processing of R0.3mm to R0.8mm.
[0012]
In the inspection method of the present invention, the pilot pin is provided at a position corresponding to the concave portion of the carrier tape to be applied, and is inserted into the concave portion of the sufficiently positioned carrier tape. As positioning means, a plurality of pilot pins may be inserted into the recesses at intervals, and positioning and inspection may be performed at the same time. A positioning pin having the same diameter as the sprocket hole is inserted into the sprocket hole for positioning. You may make it insert a pin in a recessed part.
[0013]
In the image processing apparatus used in the inspection method of the present invention, a CCD camera is used, and a pilot pin is inserted into the recess to binarize the area of the whitened portion generated in the region around the recess due to deformation. This value is detected and compared with a prescribed value, and the H and G dimensions are inspected at the same time. In addition, the area | region of a recessed part here means the area | region of the periphery including a recessed part.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic view showing an example in which a pilot pin 3 used in an inspection method of the present invention is provided in a punch press die 11 of a carrier tape 1, and FIG. 1 (a) shows a pilot pin 3 at the top dead center of the die. Is a schematic side view before insertion into the recess 2 of the carrier tape 1, and (b) is a schematic side view after the pilot pin 3 is inserted into the recess 2 of the carrier tape 1 at the bottom dead center of the mold. is there.
FIG. 2A is a partial perspective view of the tip portion of the pilot pin 3 in the present invention, and FIG. 2B is a partial perspective view of the concave portion 2 of the carrier tape 1 into which the pilot pin is inserted. FIG. 3A is a partial perspective view of an example of the carrier tape 1 applied to the inspection method of the present invention, and FIG. 3B is a partial plan view of the carrier tape 1 showing the measurement positions of the H dimension and the G dimension. FIG. FIG. 4 is a schematic side view of an image processing apparatus used in the inspection method of the present invention.
[0015]
The carrier tape 1 illustrated in FIG. 3 is formed by slitting a transparent thermoplastic resin sheet (hereinafter simply abbreviated as “sheet”) to a certain width, and by using a vacuum forming method or a pressure forming method, a concave portion 2 for housing components. Is processed.
As shown in FIG. 1, the sheet subjected to the recess processing is introduced into the press punch die 11, and a plurality of pilot pins 3 are inserted into the recess 2 to perform positioning between the pilot pins 3 and 3. 3, the sprocket hole 4 and the recess bottom hole 5 shown in FIG. 3 are punched.
[0016]
The pilot pin 3 used in the present invention shown in FIG. 2A is selected to have an optimum shape and size according to the material, thickness and product specifications (G dimension and H dimension accuracy) of the sheet. The graph of FIG. 6 shows the change conditions of the pin specifications corresponding to each factor.
The graphs (a) to (c) in FIG. 6 show the relationship between the pilot pin clearance (difference between the actually measured dimension of the recess and the pilot pin dimension: mm) and the detection accuracy of the dimensional defect. Polystyrene having a thickness of 0.25 mm is used for the sheet, and (b) is a case where vinyl chloride having a thickness of 0.25 mm is used for the sheet. The solid lines in the graph each represent the H dimension, and the dotted lines are G dimension is represented.
Further, (c) is a graph showing the relationship between the pilot pin clearance and the detection accuracy of a dimensional defect when polystyrene having a thickness of 0.25 mm to 0.45 mm is used for the sheet.
The tip of the pilot pin used in the above (a) to (c) has the same shape as the concave inner shape of the carrier tape to be applied, and the size is 0.03 mm to 0.05 mm smaller than the inner dimension of the concave, Moreover, what gave R0.2mm R process to the front-end | tip part was used.
[0017]
As shown in FIG. 4, the image processing apparatus used in the inspection method of the present invention includes a CCD camera 20 for capturing an image and an illuminating device 21, and pilot pins of the carrier tape 1 fed onto the illuminating device 21. The peripheral part of the recess 2 in which is inserted is photographed by the CCD camera 20, and the whitened area is measured by binarized image processing of the part.
FIG. 5 is a partial plan view of a detection screen obtained by performing image processing on the periphery of the concave portion of the carrier tape photographed by the CCD camera. In the figure, reference numerals 30 and 31 denote a whitening detection window, and a black portion 32 indicates the pilot pin 3. A portion changed (whitened) by insertion is shown.
[0018]
The image processing apparatus according to the present invention uses the screen detected as described above, and compares the measured values of the peripheral portion 30 of the concave portion where the pilot pin is inserted with the specified value or the region of the peripheral portion of the same concave portion where the pilot pin is not inserted. The determination is made by comparing the whitening area around the recess. The detection screen of FIG. 5 shows a case in which the determination is made by comparing the whitening area between the peripheral portion 30 of the recess where the pilot pin is inserted and the peripheral portion 31 of the recess where the adjacent pilot pin is not inserted. According to the determination method as described above, it is possible to simultaneously detect dirt, foreign matter, scratches, breakage, and the like attached to the product.
In the inspection method according to the present invention, since the inspection is performed using the image processing apparatus as described above, it is preferable to target a carrier tape using a transparent or translucent sheet.
[0019]
【Example】
Examples of the present invention will be described below, but the present invention is not limited thereto. Based on the inspection method of the present invention, an attempt was made for the case where six rows of carrier tapes having a width of 8 mm and a recess pitch of 4 mm were taken.
Using a molding drum mold on a transparent polystyrene sheet having a width of 60 mm and a thickness of 0.25 mm, a concave portion for storing components having a length and width of 1.45 mm × 2.2 mm and a depth of 1.4 mm was continuously formed by vacuum forming. .
[0020]
Next, it was led into a press punch die having 20 shots per shot, and the sprocket holes and the recess bottom holes were punched out. Here, an air feeder was used as the sheet conveying device, and the sheet was intermittently fed every 80 mm in length, and a total of 240 holes were simultaneously punched out in a single shot, 20 × 6 rows = 120 holes each for the sprocket holes and the recess bottom holes.
At this time, the positioning of the sheet was performed by placing a pilot pin having the same shape as the inside of the recess (0.02 mm smaller than the actually measured dimension value inside the recess and R processing of 0.2 mm on the tip) into the mold. Two places per line, a total of 12 places, were provided by inserting them into the recesses simultaneously with the lowering of the stripper.
As a result, the H dimension standard is 4.00 mm ± 0.10, both 3.90 or less and 4.10 or more, and the peripheral portion of the recess where the pilot pin for positioning is inserted is selectively selected by the image processing apparatus. Detectable whitening occurred. Similarly, the G dimension was detectable at both 1.95 mm or less and 2.05 mm or more with respect to the standard of 2.00 mm ± 0.05.
[0021]
【The invention's effect】
According to the inspection method of the present invention, it is possible to solve the conventional problems in detecting defects of the H dimension and G dimension of the carrier tape. That is, various changes are made to the shape and size of the pilot pins for positioning the sheet in the press punch mold, and the concave portion used as a pilot is changed (whitened) when a positioning failure occurs, so that the image processing apparatus (binarization processing) ), It is possible to simultaneously detect the H dimension and G dimension defects of the carrier tape at high speed and with high accuracy. Furthermore, adhesion of dirt, dust, foreign matter, etc. can be detected simultaneously.
[Brief description of the drawings]
FIG. 1 is a schematic view showing an example in which pilot pins used in an inspection method of the present invention are provided in a punch press mold of a carrier tape, (a) is a schematic side view of the top dead center of the mold; b) is a schematic side view of the bottom dead center.
2A is a partial perspective view of a carrier tape used in the inspection method of the present invention, and FIG. 2B is a partial perspective view of a concave portion of the carrier tape into which a pilot pin is inserted.
3A is a partial perspective view of a carrier tape applied to the inspection method of the present invention, and FIG. 3B is a schematic plan view.
FIG. 4 is a schematic side view of an image processing apparatus applied to the inspection method of the present invention.
FIG. 5 is a schematic plan view showing a state in which the concave portion of the carrier tape is determined by the image processing apparatus.
FIGS. 6A, 6B, and 6C are graphs showing pilot pin changing conditions according to sheet materials.
[Explanation of symbols]
1. ・ Carrier tape 2 ・ ・ Recess 3 ・ ・ Pilot pin 4 ・ ・ Sprocket hole 5 ・ ・ Recess bottom hole 20 ・ ・ CCD camera 21 ・ ・ Lighting device 30, 31 ・ ・ Whitening detection window 32 ・ Black part G ・・ G dimension H ・ ・ H dimension

Claims (1)

When inspecting a carrier tape in which a recess for storing electronic components and a sprocket hole for transfer are connected, a pilot pin having the same shape as the inside of the recess of the positioned carrier tape is inserted into the recess so that The image processing device detects the area of the whitened portion due to the deformation generated in the above, compares the value with a specified value, and simultaneously determines the pitch of the sprocket hole and the dimensions of the sprocket hole center and the recess center. Carrier tape inspection method.

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