JP2001249006A - Image recognition method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To avoid difficulty of shortening recognition time and avoid increase in process in the case a ring shape illumination device is used for casting waves in visible light range to a foundation structure of which the image is recognized from an insulation resin layer side. SOLUTION: The image recognition method selectively removes wave length improper for binarizing by transmitting visible light from a light source or the reflection light to a light reception machine into a wave length selection base material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an image recognition method related to positioning processing at the time of manufacturing a printed wiring board.

[0002]

2. Description of the Related Art In a printed wiring board base material comprising at least one layer of insulating resin, for example, polyimide or the like and a copper foil layer, when a mark formed of copper foil is subjected to image recognition by reflected light from the insulating layer side. In a general coaxial epi-illumination type illuminating device, a ring-type illuminating device is mainly used because binarization processing is difficult due to visible light reflection on the outer surface of the insulating resin layer.

[0003]

According to the ring type illumination device, it is possible to recognize the mark by transmitting the light through the insulating resin layer. However, the irradiation light and the reflected light are absorbed by the insulating resin layer, and the brightness of the obtained binarized image is low. As a result, the recognition accuracy may not be very good, or the binarization operation may require a relatively long time, and it is difficult to reduce the positioning processing time. In addition, an expensive recognition device had to be introduced to enable recognition in a short time.

On the other hand, in order to avoid these problems, there is a case where a measure is taken to remove the insulating resin layer covering the mark before performing the positioning recognition. Thereby, the brightness of the binarized image can be increased, and the positioning processing time can be reduced. However, for example, the insulating resin layer on the mark is removed by laser drilling, and the surface of the exposed copper foil needs a surface cleaning treatment such as plasma desmear. Alternatively, there is a disadvantage that the number of steps such as a step of punching the film is required before laminating the film to be the insulating resin layer on the copper foil, which leads to an increase in cost.

Accordingly, the present invention is directed to a positioning process for transmitting an insulating resin layer of a substrate for a printed wiring board, in which a recognition time can be reduced even with a general-purpose recognition device, and an increase in the total number of steps occurs. The purpose is to provide such a recognition method.

[0006]

SUMMARY OF THE INVENTION The present invention relates to an image recognition apparatus utilizing reflected light in the visible light range for an object to be recognized, and more specifically, a printed wiring board comprising a copper foil layer and an insulating resin layer. Visible from the insulating resin layer side of the base material
In the image recognition apparatus utilizing the reflected light of the light region, the wavelength region of the irradiated light or light to be received is characterized in that the image recognition at 400 to 550 nm, an image recognition method which can solve the conventional problems.

In order to position a substrate for a printed wiring board composed of a copper foil layer and an insulating resin layer using an image recognition device utilizing reflected light in the visible region, for example, a positioning copper removal portion is formed on the copper foil layer. Positioning can be performed by applying an alignment mark, irradiating visible light from the insulating resin layer side by ring-type illumination, and capturing a contrast image that is reflected light from the copper blank portion.

The reflected light from the copper foil surface has a wavelength range of 60
It has a strong light amount in the range of 0 to 750 nm, and absorbs light on a relatively short wavelength side in the visible light region. Therefore, when the mark formed on the copper foil is recognized from the insulating resin layer side, light in the wavelength region of 400 to 550 nm is irradiated,
A good contrast image in which the copper foil portion is dark and the copper blank portion is bright may be obtained.

[0009] From the wavelength in the visible light region, a wavelength of 400 to 55
In order to select 0 nm light and use it for image recognition, the light after passing through a wavelength selection base material that selectively gives transmittance in this wavelength region may be incident on the light receiver. A substrate using a film, glass, or the like as the substrate can be used. Further, it can be installed on both the irradiation side and the light receiving side of the recognition device.

In a general visible light irradiation halogen lamp, if the wavelength is selected, a decrease in the amount of light causes adverse effects such as a recognition failure due to insufficient luminance difference or a long recognition time in a binarization process for image recognition. Although there is a possibility, it can be avoided by optimizing the amount of transmitted light in the wavelength region of 400 to 550 nm.

In the case where the reflection of light from the copper foil surface is reduced by the selection of the wavelength and the decrease in the amount of reflected light from the copper blank portion of the mark is slight, recognition from the insulating resin layer side is satisfactory. A high contrast image can be obtained, and the recognition time can be reduced even with a general-purpose recognition device.

In some cases, the amount of light transmission may decrease depending on the thickness of the insulating resin layer through which the light in the above-mentioned wavelength range is transmitted. Can be obtained enough.

According to the recognition from the insulating resin layer side using the reflected light, when the material of the conductor layer is not copper but another metal material (for example, gold, silver, nickel, aluminum, iron, eutectic solder, etc.), the same applies. Such a problem can occur, but can be avoided by selecting light that does not include the wavelength region of the reflected light from the conductor surface.

[0014]

EXAMPLES Hereinafter, the present invention will be described in detail with reference to evaluation examples in which the present invention is implemented, but the present invention is not limited thereto.

Example 1 Rolled copper foil layer 1 (made by Mitsui Metals, FX-BSH, Rz on M-plane)
= 3.0 μm, thickness 18 μm) Polyimide resin insulation layer 2
An adhesive layer 3 is formed by casting and coating a thermoplastic silicone-modified polyimide on a polyimide resin of a flexible printed wiring board (A1 flexible manufactured by Sumitomo Bakelite) having a thickness of 25 μm (thickness: 25 μm). An adhesive-attached flexible printed wiring board 4 comprising an adhesive layer (10 μm) was obtained. A circular independent land having a diameter of 200 μm is formed by etching as a pattern for evaluation on a copper foil layer at a laser opening position, and a copper removal circle 5 having a diameter of 100 μm is simultaneously formed as an alignment mark. Obtained.

The processing position evaluation substrate was sucked onto the suction table 12 of the ultraviolet laser processing apparatus such that the adhesive layer faced upward, and the recognition environment at the time of actual processing of the semiconductor mounting substrate was reproduced. As a light source for recognition, a DC lighting method (12
V, 100 W). 1 between a halogen lamp 7 and an optical fiber guide 10 for a ring-shaped illumination 9 mounted on an objective lens 8 of a recognition camera
A wavelength selection substrate A (made of glass) 11 having visible light transmission characteristics as shown in the spectral transmittance curve shown in FIG. The image recognition device is M
USIC (ED-7810) 13 was used.

Comparative Example 1 In Example 1, when there was no wavelength selection substrate, and when the insulating resin layer on the mark had been removed in advance, the wavelength selection substrate B (made of film) having a relatively low light transmittance. In addition, the spectral transmittance curve, the recognition result, and the processing position measurement result in the case of are shown. It is clear that there is no recognition error and that the recognition, processing accuracy, and recognition time can be reduced to a level equal to or greater than that in the case of removing the insulating resin layer by selecting the irradiation wavelength and the irradiation light amount. In the case of the wavelength selection substrate B, since the light transmission amount of the selected wavelength is low, the brightness is not sufficiently obtained at the time of the binarization process, and the recognition accuracy and the speed are not significantly improved. Not zero. However, if a light source lamp having a relatively high output is used, it is considered that the recognizability is improved. In the case of the wavelength-selective substrate A, the light transmittance of the selected wavelength was relatively high, so that both the brightness and the contrast of the binarized image were good.

[0018]

[Table 1]

[0019]

According to the recognition method of the present invention, when performing positioning recognition using reflected light from the insulating resin layer side at the time of manufacturing a printed wiring board, an expensive device and a new process are not required, and a short time is required. High-precision recognition and manufacturing cost reduction can be achieved in a short time.

[Brief description of the drawings]

FIG. 1 Spectral transmittance curves of wavelength-selective substrates A and B

FIG. 2 shows the distribution of laser aperture positions for wavelength-selective substrate A.

FIG. 3 shows the distribution of laser aperture positions for wavelength-selective substrate B

FIG. 4 shows the distribution of laser aperture positions without a wavelength selection substrate.

FIG. 5 shows the distribution of laser aperture positions when the insulating resin layer is removed.

FIG. 6 is a schematic diagram of an evaluation board and a recognition device optical path system used in the embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Copper foil 2 Insulating layer 3 Adhesive layer 4 Flexible printed wiring board with adhesive 5 Alignment mark 6 Processing position evaluation board 7 Halogen lamp 8 Objective lens 9 Ring illumination 10 Optical fiber guide 11 Wavelength selection substrate A 12 Suction table 13 Image recognition apparatus

Claims (1)

[Claims] An image recognition apparatus that uses reflected light in a visible light range for an object to be recognized, and uses a wavelength selection substrate to perform image recognition in a wavelength range of 400 to 550 nm by irradiating light wavelength or receiving light wavelength. Image recognition method.