JP4526653B2 - Determining the processing timing of strip parts - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a technique for inspecting strip-shaped parts and determining execution timing of predetermined processing.
[0002]
[Prior art]
When soldering leads (terminals) to an IC chip (semiconductor integrated circuit), a component called a strip-shaped lead frame is used. A large number of terminals are periodically and repeatedly formed on the lead frame, and a sprocket hole for conveyance is provided at a side end of the lead frame.
[0003]
Conventionally, when conducting a lead frame inspection, an image of a predetermined inspection target area in the lead frame is taken while the lead frame is transported in the longitudinal direction, and the quality of each inspection target area is determined by examining the image. Was.
[0004]
[Problems to be solved by the invention]
However, when the lead frame is transported, the lead frame is displaced in a direction perpendicular to the longitudinal direction (the width direction of the lead frame), so that it is difficult to properly determine the timing for capturing an image of the inspection target area. It was. Such a problem is a common problem when not only the inspection of the lead frame but also the inspection or predetermined processing is performed on the band-shaped component in which the same planar shape appears periodically.
[0005]
The present invention has been made to solve the above-described conventional problems, and when the strip-shaped component is transported, the timing of inspection and processing can be accurately determined even when the strip-shaped component is blurred in the width direction. It aims at providing the technology which can do.
[0006]
[Means for solving the problems and their functions and effects]
In order to achieve the above object, the present invention has a substantially band-like shape in which the same planar shape periodically repeats, and a specific transmission type at a predetermined position inside a side end portion extending in the longitudinal direction. Provided is an inspection apparatus for inspecting a band-shaped component whose shape is periodically formed along the longitudinal direction. The inspection apparatus is arranged along a direction substantially perpendicular to the longitudinal direction of the band-shaped part in the conveyance path of the band-shaped part, and a photoline sensor that acquires a linear image of the band-shaped part at a predetermined time; and By analyzing a change point of the output signal output from the photoline sensor, a first output signal change point corresponding to the position of the side end is determined, and a predetermined output signal change point is determined from the first output signal change point. It is determined whether or not a second output signal change point corresponding to the specific transmissive shape exists in the range, and a state in which the second output signal change point exists in the predetermined range occurs. A trigger signal generation unit that generates a trigger signal indicating the execution timing of the inspection, and an inspection execution unit that executes the inspection according to the trigger signal.
[0007]
In this inspection device, by analyzing the change point of the output signal of the photoline sensor, an inspection trigger is triggered when a state where a specific transmissive shape exists within a predetermined range from the side edge of the band-shaped part. Since the signal is generated, it is possible to determine the inspection timing with high accuracy even when the belt-shaped component is moved in the direction perpendicular to the longitudinal direction when the belt-shaped component is conveyed.
[0008]
The trigger signal generation unit may stop generating the trigger signal when a state in which the second output signal change point exists in the predetermined range continues.
[0009]
In this way, since the trigger signal is generated only when the output signal changes to a specific state, it is possible to set the trigger signal generation timing to a more preferable one.
[0010]
The inspection apparatus may further include a light source that is provided on the opposite side of the photoline sensor with the band-shaped component interposed therebetween and that emits light toward the photoline sensor.
[0011]
In this way, a clear linear image of the transmissive part and the non-transmissive part of the belt-like component can be acquired by the photoline sensor, and therefore the inspection timing can be determined with higher accuracy.
[0012]
The inspection execution unit may include a camera that acquires a two-dimensional image including a specific inspection target region of the band-shaped part in response to the trigger signal.
[0013]
In such an inspection apparatus, since the inspection timing is determined with high accuracy, it is possible to employ a camera having a relatively narrow field of view.
[0014]
Note that the present invention can be realized in various modes, for example, a method and apparatus for inspecting strip-shaped parts, a method and apparatus for determining processing timing of strip-shaped parts, and a function of those methods or apparatuses. The present invention can be realized in the form of a computer program, a recording medium storing the computer program, a data signal including the computer program and embodied in a carrier wave, and the like.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be described based on examples. FIG. 1 is a conceptual diagram showing an outline of inspection in one embodiment of the present invention. The lead frame 10, which is a band-shaped component, is transported at a substantially constant speed in the direction of the arrow on a predetermined transport path. The inspection device performs an inspection of the lead frame 10 in this conveyance path. The inspection apparatus includes a photoline sensor 20 provided below the lead frame 10, an LED 22 that is a point light source provided on the opposite side of the photo frame sensor 20 across the lead frame 10, and a predetermined lead frame 10. The camera 24 for acquiring the two-dimensional image of the inspection target area SA and the control device 30 are provided.
[0016]
The control device 30 is constituted by a personal computer on which an interface board for the photoline sensor 20 and the camera 24 is mounted. The control device 30
A trigger generation unit 32 and an image processing unit 34 are provided. The trigger generator 32 generates a trigger signal TG according to the output signal Sph from the photoline sensor 20 and supplies it to the camera 24. The image processing unit 34 determines the quality of the lead frame by processing the image signal IM of the image captured by the camera 24. For example, the image processing unit 34 can determine the quality of the lead frame by processing the image of the inspection target area SA and inspecting whether or not the lead pin is bent more than an allowable value. It is. Note that the functions of the trigger generation unit 32 and the image processing unit 34 are realized by a CPU (not shown) in the control device 30 executing a computer program.
[0017]
The photoline sensor 20 is arranged along a direction (width direction of the lead frame 10) substantially perpendicular to the longitudinal direction (conveyance direction) of the lead frame 10. The LED 22 is disposed immediately above the photoline sensor 20 and radiates radial light toward the photoline sensor 20. As the light source, a linear or planar light source may be used instead of the LED 22 that is a point light source. Further, when there is sufficient ambient light, the light source for the photoline sensor 20 may be omitted.
[0018]
The lead frame 10 is periodically provided with sprocket holes 14 at predetermined positions inside one side end portion 12 extending in the longitudinal direction. The sprocket hole 14 is a hole into which the sprocket teeth of the transport device are inserted when the transport device (not shown) transports the lead frame 10 using the sprocket. The LED 22 irradiates light toward a position where the sprocket hole 14 is provided. The light transmitted through the transmission part of the lead frame 10 is received by the photoline sensor 20. The photoline sensor 20 acquires a linear image of the lead frame 10 at regular intervals, and supplies an output signal Sph representing the linear image to the trigger generator 32. The trigger generator 32 generates a trigger signal TG when the sprocket hole 14 of the lead frame 10 is detected.
[0019]
FIG. 2 is an explanatory diagram showing how the trigger generator 32 determines the timing for generating the trigger signal TG. FIG. 2A shows the positional relationship between the lead frame 10 and the photoline sensor 20 and the level change of the output signal Sph from the photoline sensor 20 at a certain time t1. FIG. 2B shows a state at time t2 when a predetermined time interval Δt has elapsed from time t1. During this time interval Δt, the lead frame 10 has moved a predetermined distance in the direction of the arrow (upward in the figure).
[0020]
At time t <b> 1, the position of the photoline sensor 20 is at a position immediately before it is suspended in one sprocket hole 14. A graph of the output signal Sph of the photoline sensor 20 at this time is shown in the lower part of FIG. The horizontal axis x of this graph is a position coordinate measured from one end portion 21 of the photoline sensor 20, and the value of the output signal Sph changes according to the coordinate x. The value of the output signal Sph indicates a predetermined L level (light shielding level) at a position shielded by the lead frame 10, and the value of the output signal Sph has a predetermined H level (non-light shielding level) at a position not shielded by the lead frame 10. Show. Actually, the output signal Sph of the photoline sensor 20 can take a multi-value level, but for the sake of simplicity, it is assumed here that the output signal Sph takes only two levels, an L level and an H level.
[0021]
At time t1, the output signal Sph of the photoline sensor 20 takes the H level in the range from the end 21 of the photoline sensor 20 to the coordinate x1. Further, the L level is taken in the range from the coordinate x1 to the coordinate x2, and it becomes the H level again after the coordinate x2. In this specification, the point at which the level of the output signal Sph is switched, such as the coordinates x1 and x2, is referred to as “output signal change point” or simply “change point”.
[0022]
The trigger generation unit 32 first detects a change point x1 at which the signal level switches from the H level to the L level, and recognizes this change point x1 as the position of the side end portion 12 of the lead frame 10. Further, after this first change point x1, a change point x2 at which the signal level switches from the L level to the H level is detected, and a difference Δx (= x2-x1) between the coordinate values of these change points x1 and x2 is calculated. . Further, it is checked whether or not the difference Δx is less than a preset threshold value D. This threshold value D is a value associated with the distance from the lead frame 10 to the sprocket hole 14 in a state where the photoline sensor 20 has passed through the sprocket hole 14, and is preset for each lead frame 10. Value. In the example of FIG. 2, the threshold value D is set to a value from the side end 12 to the center of the sprocket hole 14.
[0023]
At time t1, since the sprocket hole 14 does not exist at the imaging position of the photoline sensor 20, the change point coordinate difference Δx is equal to or greater than the threshold value D. In this case, the trigger generator 32 does not generate the trigger signal TG. On the other hand, at time t2, the sprocket hole 14 is present at the imaging position of the photoline sensor 20, and as a result, the change point coordinate difference Δx becomes a value less than the threshold value D. At this time, the trigger generator 32 generates a trigger signal TG, and causes the camera 24 to capture a two-dimensional image.
[0024]
In addition, after time t2, the state of Δx <D continues for a while. In such a case, generation of the trigger signal TG is stopped. That is, the trigger generation unit 32 is in a state where the difference Δx is equal to or greater than the threshold value D at the time immediately before (time t1) as in the case of time t2, and the state is then switched to a state of Δx <D. Only when the trigger signal TG is generated. In other words, the trigger signal TG is generated only when the front end portion of the sprocket hole 14 is detected. In this way, it is possible to generate the trigger signal TG only once for one sprocket hole 14.
[0025]
FIG. 3 is a flowchart showing a processing procedure by the trigger generating unit 32. In step S <b> 1, the photoline sensor 20 captures a linear image, and the output signal Sph is supplied to the trigger generator 32. In step S2, the coordinates of the first two change points x1 and x2 of the output signal Sph are detected, and the difference Δx is calculated. In step S3, whether or not the magnitude relationship between the difference Δx and the threshold value D is switched from the first state (the difference Δx is equal to or less than the threshold value D) to the second state (the difference Δx is less than the threshold value D). Determined. If the magnitude relationship has not been switched, the process returns to step S1, and a linear image is captured again by the photoline sensor 20 after a predetermined time interval. On the other hand, when the magnitude relationship is switched, the trigger signal TG is generated in step S4.
[0026]
In addition, as a judgment criterion in step S3, instead of “whether or not it is switched to Δx <D”, a judgment criterion “whether or not it is switched to D1 <Δx <D2” (D1 and D2 are predetermined values other than 0). May be used. That is, in step S3, it may be determined whether or not the difference Δx is within a predetermined range.
[0027]
Further, instead of the procedure of FIG. 3, the trigger signal TG may be generated whenever Δx <D. At this time, since the trigger signal TG is continuously generated when the state of Δx <D is continued, the camera 24 outputs the trigger signal TG for the second and subsequent times among the continuously generated trigger signals TG. Ignore it.
[0028]
FIG. 4A is a front view showing a mechanical configuration of the inspection apparatus of the present embodiment, and FIG. 4B is a plan view of the base 100. The lead frame is conveyed in the direction indicated by the arrow (to the right in the figure). At both ends of the base 100, guide plates 110 and 112 for guiding the side end portions of the lead frame are provided. The guide plates 110 and 112 can arbitrarily change the distance between the opposing guide surfaces. In addition, on the base 100, transport tables 120, 122, and 124 are provided. The central carrier 122 is located below the camera 24, and the surface is covered with a material having light absorption characteristics (for example, black paper) in order to improve the contrast of an image captured by the camera 24. .
[0029]
Two photoline sensors 20 a and 20 b are provided near the right end of the base 100. As shown in FIG. 4B, these two photoline sensors 20a and 20b are arranged at positions shifted from each other along a direction perpendicular to the transport direction. The reason why the two photoline sensors 20a and 20b are provided is that the inspection timing can be well determined when the sprocket hole is present on either side of the two side ends of the lead frame. It is. Some lead frames are provided with sprocket holes in both of the two side end portions. In this case, the inspection timing can be determined using only the sprocket holes existing in the vicinity of one of the side end portions.
[0030]
A columnar arm 200 is vertically provided at one end of the base 100 on the side where the photoline sensor 20 exists. Note that the lower portion of the columnar arm 200 is shown in a partially cutaway state. On the top of the columnar arm 200, two LEDs 22a and 22b are provided at positions directly above the two photoline sensors 20a and 20b. The upper end portion of the columnar arm 200 is bent at a substantially right angle, and constitutes a horizontal arm 202 extending horizontally.
[0031]
A vertical movement plate 210 is provided at the tip of the horizontal arm 202, and a horizontal movement plate 220 is provided at the tip of the vertical movement plate 210. A camera 24 is attached to the left / right moving plate 220. The vertical movement plate 210 moves up and down according to the rotation of the vertical movement adjustment screw 212. Further, the left / right moving plate 220 moves to the left / right according to the rotation of the left / right movement adjusting screw 222. Using these adjusting screws 212 and 222, the vertical and horizontal positions of the camera 24 can be set to desired imaging positions.
[0032]
As described above, in this embodiment, the position x1 of the side end 12 of the lead frame 10 is detected from the output signal Sph of the photoline sensor 20, and within a predetermined distance D from the side end. Since it is detected whether or not the sprocket hole 14 is present, the sprocket hole 14 is also present even when the lead frame 10 is slightly displaced in the direction perpendicular to the longitudinal direction (conveying direction) (the width direction of the lead frame). Whether or not to perform (that is, inspection timing) can be determined with high accuracy. In addition, since the inspection timing can be determined with high accuracy, it is possible to set the inspection target area SA (FIG. 1) imaged by the camera 24 to be smaller than the conventional one. When the inspection target area SA is reduced, the amount of processing by the image processing unit 34 is reduced, which has the advantage that the time required for the inspection can be shortened.
[0033]
The present invention is not limited to the above-described examples and embodiments, and can be implemented in various modes without departing from the gist thereof. For example, the following modifications are possible.
[0034]
(1) In the above embodiment, a part of the configuration realized by hardware may be replaced with software, and conversely, a part of the configuration realized by software may be replaced with hardware. Also good. For example, a part of the function of each unit of the control device 30 (FIG. 1) can be executed by a dedicated hardware circuit.
[0035]
(2) In the above embodiment, the trigger signal TG is generated immediately when the front end of the sprocket hole 14 is detected. However, the trigger signal TG may be generated after a predetermined time delay.
[0036]
(3) Although the trigger signal TG is generated at the front end portion of the sprocket hole 14 in the above embodiment, the trigger signal TG may be generated at the rear end portion instead.
[0037]
Instead of generating the trigger signal TG for each sprocket hole 14, the trigger signal TG may be generated once for each of the plurality of sprocket holes 14. Therefore, in general, the trigger signal TG may be generated once every N sprocket holes 14 (N is a predetermined integer equal to or greater than 1).
[0038]
In the above embodiment, the sprocket hole 14 is used as a specific shape that defines the timing for generating the trigger signal TG. However, the trigger signal TG is generated using a specific shape other than the sprocket hole 14. It may be. However, as the specific shape used for generating the trigger signal TG, it is preferable to use a shape having a portion that transmits light and a portion that does not transmit light (referred to as a “transmissive shape”).
[0039]
(4) In the above-described embodiment, the inspection apparatus that acquires and inspects an image of a predetermined inspection target area in the strip-shaped lead frame 10 has been described. However, the present invention can inspect strip-shaped components other than the lead frame. It is also applicable to the device. Further, the present invention can be applied to a processing apparatus for performing a specific process for a band-shaped part, instead of a belt-shaped part inspection apparatus. As a specific process related to the band-shaped part, for example, there is a process of applying a chemical to a part of the band-shaped part.
[Brief description of the drawings]
FIG. 1 is a conceptual diagram showing an outline of inspection in one embodiment of the present invention.
FIG. 2 is an explanatory diagram showing how the trigger generator 32 determines the timing for generating a trigger signal TG.
FIG. 3 is a flowchart showing a processing procedure by a trigger generation unit 32;
FIG. 4 is a diagram illustrating a mechanical configuration of the inspection apparatus according to the present embodiment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Lead frame 12 ... Side edge part 14 ... Sprocket hole 20, 20a, 20b ... Photo line sensor 21 ... End part 22, 22a, 22b ... LED
24 ... Camera 30 ... Control device 32 ... Trigger generating unit 34 ... Image processing unit 40 ... Control circuit 88 ... Host computer 100 ... Base 110, 112 ... Guide plate 120, 122, 124 ... Conveying table 200 ... Columnar arm 202 ... Horizontal Arm 210 ... Vertical movement plate 212 ... Vertical movement adjustment screw 220 ... Left / right movement plate 222 ... Left / right movement adjustment screw

Claims (5)

It has a substantially band-like shape in which the same planar shape periodically repeats, and a specific transmissive shape is periodically formed along the longitudinal direction at a predetermined position inside a side end portion extending in the longitudinal direction. An inspection device for inspecting a strip-shaped part,
A photoline sensor that is arranged along a direction substantially perpendicular to the longitudinal direction of the belt-like component in the transport path of the belt-like component, and obtains a linear image of the belt-like component every predetermined time;
By analyzing a change point of the output signal output from the photoline sensor, a first output signal change point corresponding to the position of the side end is determined, and a predetermined value is determined from the first output signal change point. It is determined whether or not there is a second output signal change point corresponding to the specific transmissive shape within the range, and there is a state where the second output signal change point exists within the predetermined range. A trigger signal generator that generates a trigger signal indicating the execution timing of the inspection when it occurs,
An inspection execution unit that executes the inspection in response to the trigger signal;
A device for inspecting strip-shaped parts, comprising: The apparatus of claim 1, comprising:
The apparatus for inspecting a strip-shaped component, wherein the trigger signal generation unit stops generating the trigger signal when a state in which the second output signal change point exists in the predetermined range continues. The apparatus according to claim 1 or 2, further comprising:
An apparatus for inspecting a band-shaped part, comprising a light source that is provided on the opposite side of the photoline sensor with the band-shaped part interposed therebetween and that emits light toward the photoline sensor. An apparatus according to any one of claims 1 to 3,
The said inspection execution part is an inspection apparatus of a strip | belt-shaped component containing the camera which acquires the two-dimensional image containing the specific test | inspection area | region of the said strip | belt-shaped component in response to the said trigger signal. It has a substantially band-like shape in which the same planar shape periodically repeats, and a specific transmissive shape is periodically formed along the longitudinal direction at a predetermined position inside a side end portion extending in the longitudinal direction. An apparatus for determining a processing timing for executing a predetermined process with respect to a belt-shaped part that is provided,
A photoline sensor that is arranged along a direction substantially perpendicular to the longitudinal direction of the strip-shaped component in the transport path of the strip-shaped component, and acquires a linear image of the strip-shaped component every predetermined time;
By analyzing a change point of the output signal output from the photoline sensor, a first output signal change point corresponding to the position of the side end is determined, and a predetermined value is determined from the first output signal change point. It is determined whether or not there is a second output signal change point corresponding to the specific transmissive shape within the range, and there is a state where the second output signal change point exists within the predetermined range. A trigger signal generating unit that generates a trigger signal indicating the execution timing of the predetermined process when it occurs,
A processing timing determination device comprising:

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