JPS60200218A - Lighting method - Google Patents

Abstract

PURPOSE:To eliminate the thermal influence of a light emission source upon a body to be tested and realize high-illuminance lighting by irradiating a pattern with light from the light emission source successively to high illuminance through plural optical fibers by using a reflecting mirror which rotates around the light source. CONSTITUTION:Optical fibers 91-9n are arranged around the lamp 2 and one- side terminals of them are arranged and fixed in a line so as to illuminate one surface of the body 1 to be tested. Further, the arcuate reflecting mirror 10 is provided and rotates around the lamp 2. Light emitted by the lamp 2 is reflected by reflecting mirror 10 which rotates, and a parallel light beam W illuminates one-side terminals of the optical fibers 91-9n and is transmitted to the other- side terminal to illuminate the body 1 to be tested successively, so that a specific detection part recognizes and tests the pattern. Consequently, the thermal influence of the light emission source upon the objective body 1 is prevented and high-brightness lighting is attained to improve the reliability of the pattern test.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Technical Field of the Invention The present invention relates to an illumination method for optically reading patterns on printed circuit boards, photomasks for printed circuit boards, and the like.

Problems with the Prior Art In recent years, many integrated circuit components and small electrical components have been used in electrical circuits on printed circuit boards, and the electrical performance has been improved and miniaturized. Therefore, patterns on printed circuit boards that form electric circuits are required to have high density and high precision.

Conventionally, such tests on patterns of printed circuit boards and photomasks for printed circuit boards have been carried out using a method as shown in the perspective views of main parts shown in FIGS. 1 and 2 for explaining the test method.

That is, as a method for pattern testing, the lamp 2 is caused to emit light as shown in the perspective view of the main part in FIG. The emitted light becomes highly illuminant by the reflecting mirror 3 and condensing lens 4 provided on the back and front sides of the lamp 2, and is focused on one plane of the test object 1 of a flat printed board or a photomask for printed board. irradiate the position. On the other hand, test object 1
A light detection unit 5 composed of a lens 51 and a photodetector 52 is provided above the other plane of the test object 1, and collects and detects the pattern light projected onto the other plane of the test object 1. It processes signals and recognizes patterns.

We are testing whether or not. In this method, the lamp 2 is sequentially mechanically moved to irradiate the subject 1, and in synchronization with the movement of the lamp 2, the light detection section 5 is also mechanically moved. This moving mechanism must always move corresponding positions on both sides of the test object 1 in synchronization. As a result, the mechanism becomes complicated, and synchronization and tracking accuracy may deteriorate, resulting in a decrease in detection ability and the reliability of the test.

Another method for pattern testing is to use a long lamp 8 as a light emitting source to illuminate the entire surface of the subject l, as shown in the perspective view of the main part of FIG. Although this method does not require the moving mechanism described in FIG.
It is necessary to irradiate the entire surface of the subject 1 with high illuminance, requiring a large amount of power for the lamp, and the subject 1 may be damaged due to heat conduction due to heat generated by the lamp.

(0) Purpose of the invention The present invention has been devised in view of the above-mentioned conventional drawbacks.

The object of this invention is to provide an illumination method that can easily illuminate a predetermined position of a test object with high illuminance without affecting the test object due to the heat generated by the light emitting source.

(cO Structure and object of the invention) According to the present invention, there is provided an illumination method for irradiating a pattern formed on a plane object with light and optically reading the pattern, the illumination method comprising: One end is arranged around the illumination light source, the other end is arranged in a line according to the arrangement order, and an arc shape rotates around the illumination light source between the illumination light source and one end of the optical fiber. This is achieved by an illumination method characterized in that the illumination method is provided with a reflecting mirror consisting of a rotatable reflecting mirror, and the pattern is sequentially irradiated with the illuminance of the light source at high illuminance through the optical fiber.

(e) Embodiment of the Invention Hereinafter, one embodiment of the present invention will be explained in detail. Fig. 3 is a configuration diagram of the light irradiation system for explaining the light irradiation system of the embodiment, Fig. 4 is a side view of the irradiation system of Fig. 3, and Fig. 5 is a diagram for explaining the irradiation system of the light emitting source of the embodiment. The same reference numerals as in FIGS. 1 and 2 indicate the same parts.

That is, as shown in the irradiation system configuration diagram in FIG. 3, one end of each of the optical fibers 91 to 9n is arranged at equal intervals around the lamp 2, and the other end is arranged in the above arrangement order. They are arranged in a line according to the following. The other end of the array is fixedly installed so as to irradiate one surface of the test object 1. Further, an arc-shaped reflecting mirror 10 is provided between one end of the disposed optical fibers 91 to 9n and the lamp 2. Further, this reflecting mirror 10 has a structure that allows it to rotate around the lamp 2.

The optical system of the irradiation light will be explained with reference to the configuration diagram of the light emitting source shown in FIG. That is, as shown in the figure, an arc-shaped reflecting mirror 10 receives the light emitted from the lamp 2, and is arranged around the lamp 2 as a parallel light beam W having a predetermined width corresponding to the arc shape. reflected at one end of the optical fiber. Further, the reflecting mirror 10 has a structure that rotates while maintaining an equal distance from the filament 21 of the lamp 2, and by rotating this reflecting mirror 10 in a fixed direction with a motor, the parallel light beam W is synchronized with the rotation. moves and sequentially illuminates one end of the optical fiber.

Next, each of the optical fibers 91 to 9n transmits the reflected light sequentially irradiated onto one end thereof to the other end.

As shown in A of FIG. 3, this transmitted light is linearly and sequentially emitted from the other ends of the optical fibers 91 to 9n arranged in a row, and linearly and sequentially irradiates one surface of the test object 1. do.

Therefore, as shown in FIG. 4, by moving the test object 1 in the direction (X-Y direction) perpendicular to this linearly irradiated irradiation light B, the entire surface of one side of the test object l is Sequential irradiation and selective irradiation to necessary areas can be performed. By this irradiation, a pattern is recognized by the light detection unit 5 fixedly installed in correspondence with the optical fibers 91 to 9n with the object under test 1 in between, and a pattern test of the object under test 1 is performed.

Note that the illumination range varies depending on the size, shape, and mounting position of the rotating reflector, so the optimal illumination can be selected by changing these.

(fl Effects of the Invention As is clear from the above explanation, in short, light from a light emitting source that is sequentially reflected by a rotating reflecting mirror is transmitted through an optical fiber, and the light is linearly and sequentially irradiated onto the test object. As a result, the distance between the light source and the test object can be maintained, which eliminates the effect of the heat from the light source on the test object, and the necessary parts can be illuminated with high brightness using a simple movement mechanism for the test object. The reliability of pattern testing can be improved.

[Brief explanation of the drawing]

1 and 2 are perspective views of main parts for explaining the conventional pattern testing method, FIG. 3 is a configuration diagram of the light irradiation system for explaining the light irradiation system of the embodiment, and FIG. FIG. 5 is a side view of the irradiation system shown in the figure, and FIG. 5 shows a configuration diagram of the light emitting source for explaining the irradiation system of the light emitting source of the embodiment. In the figure, l is the test object, 2.8 is a lamp, 3 is a reflecting mirror, 4 is a condensing lens, 5 is a light detection section, 51 is a lens, 5
2 is a photodetector, 7 is a signal processing circuit, 91 to 9n are optical fibers, 10 is a reflecting mirror, and 21 is a filament. Figure 1 Figure 3 Figure 4 Figure 5

Claims (1)

[Claims] An illumination method for illuminating a pattern formed on a planar object with light and optically reading the pattern, the method comprising: disposing one end of each of a plurality of optical fibers around an illumination light source; A reflecting mirror arranged in a line according to the arrangement order and having an arc shape rotating around the illumination light source is provided between the illumination light source and one end of the optical fiber, and the rotating reflection mirror rotates the light source. An illumination method characterized in that the pattern is sequentially irradiated with high illuminance through the optical fiber.