JPH06100449B2 - Coating film inspection device for resistors - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention is an inspection for determining the quality of a coating film applied to the outer periphery of a body of a resistor formed by joining cap-shaped terminals to both ends of the body. It relates to the device.

[Conventional technology]

The so-called leadless resistor 1, as shown in FIG.
A resistance coating C is formed on the outer peripheral surface of a circular pouring bobbin B made of porcelain having insulating properties, and cap-shaped terminals D, at both ends of the bobbin B,
After the D is fitted and fixed, the outer peripheral surface of the resistive film C in the body F excluding both terminals D, D is coated with a coating E by applying an insulation resistant or non-conductive paint. But,
When the coating film E is formed on the body F, unevenness may occur, such as a part where no coating film is formed or a part where the thickness of the coating film is extremely thin, or a part where the coating film is extremely thick. is there.

Conventionally, as a device for inspecting the quality (appearance) of such a coating film, in the inspection with the naked eye, there are large variations due to individual differences of the inspector, and there is inefficiency due to eye fatigue. JP-A-58-167407 discloses that the diameter of a cylindrical body is measured at three or more points along the central axis of the cylindrical body in FIG. However, the measuring device used for this measurement is 3
Since it is a contactor that makes point contact, it has a mechanical structure and a width dimension above a certain level, so if the diameter and length of the body part are small, such as a cylindrical resistor, the contact surface of the contactor Since it simultaneously contacts multiple locations in the longitudinal direction (axial direction) of the body of the resistor, it is not possible to detect the difference in the diameter of the body between the center of the body in the longitudinal direction and the location near the terminals. there were.

Therefore, as shown in FIG. 5 (a), the outer peripheral shape of the body F of the resistor 1 is such that the outer diameter of the midway portion along the axial direction of the body F is larger than the outer diameter of the cap-shaped terminals D at both ends. The outer diameter of the midway portion along the axial direction of the body F becomes smaller than the outer diameter of the cap-shaped terminals D at both ends, as shown in FIG. 5 (b). Alternatively, as shown in FIG. 5 (c), it is not possible to measure various defective shapes, such as the outer diameter of one of which is large along the longitudinal direction of the body F and becomes smaller toward the other. there were.

Moreover, since the coating film of the resistor is scraped by the contactor, the coating film at the contact point is peeled off or the thickness of the coating film is reduced due to the inspection work. A fatal defect could occur during inspection.

As means for solving this inconvenience, Japanese Patent Laid-Open No. 60-76134 discloses that a cylindrical member such as a resistor is advanced and transferred in a direction orthogonal to its axis, and the cylindrical member being transferred is used as a light source and an image sensor. A configuration is disclosed in which an image is sandwiched between (line sensors) and an image is inspected to inspect the external appearance of the cylindrical member.

[Problems to be solved by the invention]

According to this device, the axial lead portions on both the left and right sides of the columnar member are supported by the grooved support provided on the pair of left and right chain conveyors, but the columnar member itself does not rotate. With this configuration, the diameter of the cylindrical member such as the resistor in the direction parallel to the optical axis from the light source cannot be measured, and the cylindrical member is rotated around the axis by a separate means ( It had to be rotated.

The present invention has been made to solve the above-mentioned conventional problems, and uses an optical non-contact image sensor,
In addition, it is an object of the present invention to provide a device capable of accurately and quickly inspecting the outer diameter (appearance) of a plurality of portions of a body of a microminiature resistor, which has been impossible in the past, by devising a transfer means. is there.

[Means for solving problems]

Therefore, the device for inspecting a coating film in the resistor of the present invention includes a resistor having cap-shaped terminals at both ends of a body whose outer periphery is coated, while rotating the resistor about the horizontal axis of the body and the terminal while rotating the horizontal axis line. And a light source and an image sensor, which are arranged so as to face each other with the resistor being transferred therebetween, and a belt conveyor that moves the transfer means along the table surface. The belt conveyor is provided with engaging holes at which the resistors are fitted at appropriate intervals so that the resistors can rotate, and the image sensor is arranged so that the horizontal axis direction of the body of the resistors in the resistors is within the engaging holes. The size of the outer diameter is compared and detected at at least three locations with appropriate separation.

[Operation and effect of the invention]

As described above, according to the present invention, since the outer diameter of the body of the resistor is detected by the image sensor of the non-contact optical system, there is nothing that contacts the outer periphery of the body of the resistor as the inspection object. No more accidents such as peeling of the coating film by inspection.
Since the width of the light beam to be applied can also be made extremely small, even if the length of the body of the resistor is extremely short, it is possible to detect an arbitrary point separately over a plurality of points.

Further, in the present invention, since the size of the outer diameter of at least three locations in the horizontal axis direction (longitudinal direction) of the body is detected by comparison, by changing the outer diameter of the body of the resistor along the longitudinal direction, It is possible to easily discriminate various defects in the outer shape of the body as shown in FIG.

Further, the transfer means is a belt conveyor that moves along the surface of the table, and the belt conveyor is provided with engaging holes that allow the resistors to be fitted at appropriate intervals so as to rotate. , The lower surface of the resistor fitted in each engaging hole contacts the table, and the movement of the belt conveyor causes
Since the resistors can be continuously inspected while rotating around the horizontal axis of the body without being displaced in the engagement hole, the entire outer circumference of the body can be inspected and even if only one side has a defect. Can be detected.

Therefore, it is possible to eliminate the variation and inefficiency of the inspection with the naked eye, and to perform the accurate and accurate inspection of the outer diameter and the appearance of the microminiature resistor continuously and quickly.

〔Example〕

An embodiment of the present invention will be described below. In the inspection device 2 shown in the drawing, a belt conveyor 5 having an engaging hole 4 that moves in the direction of the arrow (a) is arranged on the upper surface of a table 3 so as to face each other. It comprises three pairs of light sources 6 and an image sensor 7.

The table 3 is formed with a concave groove 8 having a longitudinal direction in which the resistor 1 supports the lower surfaces of the cap-shaped terminals D, D at both left and right ends thereof. On the other hand, the belt conveyor 5 has a concave groove 8 above the concave groove 8. An engaging hole 4 into which the resistor 1 as a whole can be fitted is formed substantially in conformity with. A light source 6 is provided at a substantially central portion of the engaging hole 4.
Is formed in the large-sized portion 4a so that the irradiation light from the can be improvedly penetrated. Therefore, as the belt conveyor 5 advances, the resistors 1 fitted in the respective engagement holes 4 are connected to the terminals D, D.
While being rotated around the axis of, it is transferred in the direction of arrow (a).

The pair of the three pairs of light sources 6a, 6b, 6c and the image sensors 7a, 7b, 7c is a predetermined (I) line, which is separated by an appropriate interval dimension (h) in the longitudinal direction of the body F of the resistor 1, ( II) line,
(III) The line is arranged so that the outside diameter of the line can be detected by each person.

Each of the light sources 6a, 6b, 6c uses a light emitting diode or the like that emits an irradiation light such as visible light or infrared light, and is provided at the bottom of the groove 8 of the table 3 at appropriate intervals in the traveling direction of the belt conveyor 5.

On the other hand, each of the image sensors 7a, 7b, 7c arranged facing each other corresponding to each of the light sources has a large number of pixels in which a large number of photodiodes are arranged along each line at a minute interval of 14 μm or the like. One-dimensional CCD (Charge
Coupled Device) and the like, and by electrically detecting a change in the position of the light beam blocked by the body F of the resistor 1 between the light source and the image sensor, the outer diameter of the body F is made non-contact type. Each image sensor 7a, 7b, 7c is connected to a controller 10 via a link unit 9 so that it can be measured.

Reference numeral 11 is a vacuum suction device disposed behind the inspection device 2 and above the belt conveyor 5 for sucking and removing the resistor 1 which is determined to be defective by the inspection device 2.

In this configuration, as shown in FIGS. 1 and 2, the body F of each resistor 1 fitted in each engagement hole of the belt conveyor 5 and transported while rotating is the (I) line at the left end thereof. The outer diameter is detected by the pair of the light source 6a and the image sensor 7a at the point, the outer diameter at the line (II) is detected by the pair of the light source 6b and the image sensor 7b, and the outer diameter at the line (III) is the light source 6c. And the image sensor 7c.

Therefore, the controller 10 is connected via the link unit 9.
By comparing the results of measuring the outer diameter of each line, it is determined that the measured value of the outer diameter of the (II) line is larger than the measured values of the (I) and (III) lines on the left and right sides thereof. This corresponds to the case where the outer diameter shape of the body F of the container 1 is a drum shape in which the outer diameter of the central portion is large as shown in Fig. 5 (a). In such a shape, the outer diameter at the line (II) is the cap. If the diameter of the terminal D is larger than the diameter of the terminal D, the defective adhesion is likely to occur when the resistor 1 is mounted on the substrate of the integrated circuit. Further, in the above case, when the measured value of the outer diameter in the lines (I) and (III) does not reach the reference value, it is judged that there is a possibility of defective insulation or defective moisture resistance, and Even if the measured values on both lines reach the standard (II)
The outer diameter at the base of the terminal D can be predicted from the calculation of the taper angle based on the size comparison with the line, and when they exceed or fall below the specified value, it can be judged as defective.

Similarly, if it is determined that the measured value of the outer diameter on the line (II) is smaller than the measured values on the left and right sides of the lines (I) and (III), the outer diameter shape of the body F of the resistor 1 becomes This corresponds to the case where the outer diameter of the central portion has a constricted drum shape as shown in FIG. 5B, and in that case, if the diameter of the central portion is smaller than the specified value, there is a possibility of poor insulation or poor moisture resistance. Is judged as defective, and (I) on both left and right sides,
(III) If the outside diameter of the line is too large, the resistor 1
Since the performance of adhering to the substrate becomes poor, it is judged to be defective.

Furthermore, if the outer diameter decreases in the order of (I), (II), and (III) of the line, it is judged that the conical shape shown in (c) of FIG. The outer diameter of the root of the body F and the terminal D can be calculated from the taper angle to determine whether or not it is within the range of the specified value.

In any case, when it is determined that the defect is the same as described above, the vacuum suction device 11 on the rear side may suction and remove it.

In the above embodiment, the plurality of pairs of light sources and the image sensor are arranged at the right and left sides of the body of the resistor at appropriate intervals in the traveling direction, thereby preventing the interference of the arrangement of the plurality of image sensors. Although it is possible to measure a plurality of locations of the outer diameter of the body of the microminiature resistor, they may be arranged in parallel to the left and right when the dimensions of the image sensor or the like allow.

Further, it goes without saying that the present invention can also be applied to a resistor in which lead wires project outside the terminals D on both the left and right sides.

[Brief description of drawings]

1 to 3 show an apparatus according to an embodiment of the present invention, FIG. 1 is a schematic side view, FIG. 2 is an enlarged sectional view taken along line II-II of FIG. 1, and FIG. III-III line top view of the figure, 4th
FIG. 5 and FIG. 5 are explanatory views each showing the shape of the resistor. 1 ... resistor, 2 ... inspection device, 3,20 ... table, 22
...... Contacts, 4 …… Engagement holes, 5 …… Belt conveyors, 6,
6a, 6b, 6c …… Light source, 7,7a, 7b, 7c …… Image sensor, 8
...... Concave groove, 9 ...... Link unit 9, 10 ...... Controller.

Claims (1)

[Claims] 1. A transfer in which a resistor having cap-shaped terminals at both ends of a body having a coated outer periphery is rotated about a horizontal axis of the body and the terminal while advancing in a lateral direction perpendicular to the horizontal axis. Means, a light source and an image sensor, which are arranged to face each other with the resistor being transferred therebetween, and a belt conveyor for moving the transfer means along the surface of the table. In the image sensor, at least three outer portions are appropriately separated in the horizontal axis direction of the body of the resistor in the engaging hole by the image sensor. An apparatus for inspecting a coating film in a resistor, which is capable of comparing and detecting the size of a diameter.