JP3125551U - Surface light source device for image recognition - Google Patents

Abstract

A surface light source device capable of recognizing an image with parallel rays. In addition, a highly accurate image can be captured.
[Solution]
When manufacturing or inspecting power elements including diodes, power transistors, or elements including printed wiring circuit boards and liquid crystal panels, to project the target image on the surface of the target object, or project the target image onto the inspection apparatus In the light source device used for capturing by the light source, a surface having a size that covers the entire target image and exerting an electroluminescence function in order to project a desired image pattern onto the target by parallel rays It is assumed that the light source has a surface light source 11 and a frame 14, which is a surface light source mounting base material formed in substantially the same shape as the surface light source 11 to support the surface light source 11.
[Selection] Figure 1

Description

  The present invention provides a target image such as a circuit image pattern on the surface of a sample, which is a target, when manufacturing or inspecting power elements such as diodes and power transistors, or printed circuit boards, liquid crystal panels, and other elements. The present invention relates to a light source device used for projecting or capturing an object image into an inspection apparatus.

  For example, in an exposure machine for manufacturing printed wiring circuit boards, an image is captured by a CCD (Charge Coupled Device Image Sensor) when aligning an image pattern, but when a point light source is used as in the past Had the problem of more or less lack of clarity. FIG. 7 shows the relationship between the point light source k, the image pattern l, and the projected image. In the image pattern l, light circulates inward from the edge due to light diffraction, and a ghost (light shadow) l ″ is generated. The ring gap l ′ of the image pattern is thinned, and critically, there arises a problem that the numbers 7 and 1 are difficult to distinguish.

  In many cases, a halogen lamp, an LED (light emitting diode), or the like is used as a light source, and all of these cause the above problems. This is because, since it is a point light source, there are inevitable problems such as light diffraction and irregular reflection. However, the occurrence of the light shadow l ″ around the image pattern causes many pixel losses during image processing by the CCD sensor, and the image is not accurately recognized, and there are many problems.

JP-A-7-239551 Japanese Patent Application Laid-Open No. 7-291662

  The present invention has been made paying attention to the above-mentioned points, and an object thereof is to provide a surface light source device capable of recognizing an image with parallel rays. Another object of the present invention is to capture a highly accurate image.

  In order to solve the above-described problems, the present invention projects a target image on the surface of a target when manufacturing or inspecting a power device including a diode, a power transistor, or a device including a printed wiring circuit board and a liquid crystal panel. In order to project a desired image pattern onto a target object with parallel light beams in a light source device used for capturing the target image on the inspection apparatus or for projecting the target image on the inspection apparatus, The surface light source is composed of a surface light source composed of a surface light-emitting unit that exhibits an electroluminescence function, and a frame that is a surface light source mounting substrate formed in substantially the same shape as the surface light source to support the surface light source. And the means that it is provided as one. The surface light emitting unit is a transmission illumination light source that transmits the target image and projects the target image on the target, or a reflective illumination surface that has an opening in the surface light emitting unit and guides the target image to the target from the opening. Either form of light source can be taken.

  The surface light source device of the present invention is a circuit image pattern or the like on the surface of a target sample or the like when manufacturing or inspecting power elements such as diodes and power transistors, or printed circuit boards, liquid crystal panels, and other elements. It is used for projecting the target image of the target or for capturing the target image into the inspection apparatus. In the present invention, the target is, for the diode, a wafer made of single crystal silicon, an imaging surface of a CCD, or the like. The target image means an image that is a projection target. In addition, in the case of projection, in the present invention, it refers to projecting or capturing a target image on the surface of a target object regardless of whether it is transmitted illumination or reflected illumination.

  In the present invention, a surface light emitting element or a surface light emitting film having a size that covers the entire target image such as an image pattern of a circuit is used as a surface light source. An electroluminescence sheet (EL sheet) can be applied as the surface light emitting element. An electroluminescence sheet has a structure in which, for example, a surface electrode including a light emitting layer and a back electrode are disposed with an insulating layer interposed therebetween, and an AC voltage is applied to both electrodes via an inverter. Since the phosphor is dispersed in the binder, it functions as a sheet-like surface light emitting element that can emit light over the entire surface. In addition, the surface light emitting portion that exhibits the electroluminescence function may be formed by forming a film forming portion in which the phosphor is dispersed in the high dielectric constant binder on the surface light emitting portion by a film forming means such as a sputtering method or a printing method.

  Therefore, a desired image pattern can be reflected on the surface of the target by parallel light rays based on a surface light source that the electroluminescence function has. As shown in FIG. 8A, since the image pattern is projected onto the target surface by parallel rays using an EL sheet as a surface light source J, the target image L is projected onto the surface of the target M as a clear projection image L ′. Is done. Therefore, the figure such as 7 and 1 shown in FIGS. 8B and 8C does not cause a light shadow on the edge, and the image has a clear annulus of the same shape and size. It can be projected.

  The present invention is configured and operates as described above, and can recognize an image by using parallel rays. Therefore, the image can be clearly displayed without causing many pixel losses as in the conventional image recognition using a point light source. Recognition is possible, high-accuracy image capture is realized, and it is advantageous in terms of cost and durability.

  Hereinafter, the present invention will be described in more detail with reference to illustrated embodiments. FIG. 1 relates to Example 1 showing an image recognition surface light source device 10 according to the present invention configured for transmitted illumination, wherein 11 is an electroluminescence sheet which is a surface light source, 12 is an insulating case, and 13 is The electroluminescent sheet 11 is an electric cord, and is formed in a flat shape so as to be stretched around a circular frame 14 that is a surface light source mounting base material, and is provided integrally.

  As shown in FIG. 5, the transmitted light surface light source device 10 is for projecting onto a target 16 composed of a CCD image sensor, for example, using a work target mark 15 as a target image. The work target mark 15 is provided on the work stage 18 operated by the alignment mechanism 17. The light source light in the transmitted illumination surface light source device 10 passes through the phototool target mark 15 ′ and the work target mark 15 to reach the target 16 as a parallel light beam, and forms a clear projection image there. Since the parallel light beams are generated by the surface light source device 10, the conventional point light source light does not cause diffraction, local reflection, or the like, and image recognition errors can be greatly reduced.

  FIG. 2 relates to Example 2 showing an image recognition surface light source device 20 according to the present invention configured for reflected illumination, and 21 is a surface light source formed in a planar shape with an opening 25 in the center. An electroluminescent sheet, 22 is an insulating case, 23 is an electric cord, 24 is a circular frame which is a surface light source mounting base, and the electroluminescent sheet 21 is provided integrally with the frame 24. . FIG. 3 relates to Example 3 showing the surface light source device 30 for reflected illumination, and 31 is an electroluminescent film formed on the inner surface of a frame 34 formed in a truncated cone shape which is a surface light source mounting base material. A surface light emitting unit that is a surface light source that exhibits a sense function, 32 is an insulating case, 33 is an electric cord, and 25 is an opening in the center. Also in Example 3, the surface light emitting unit 31 is integral with the frame 34.

  The surface light source devices 20 and 30 for reflected illumination shown in FIGS. 2 and 3 are used in an arrangement as shown in FIG. That is, the work target mark 15 is provided on the work stage 18 operated by the alignment mechanism 17, while the target 16 made up of a CCD image sensor is arranged outside, and between these, Reflective illumination surface light source devices 20 and 30 are arranged, and a target image such as the work target mark 15 is guided to the target 16 from the openings 25 and 35 in the center of each surface light source device 20 and 30. Therefore, the light source light of the surface light source device 20 illuminates the phototool target mark 15 ′ and the work target mark 15 with parallel rays, and the target image is formed on the target 16. The high-luminance surface light source device 30 can also be used in the same manner as described above. However, since it has higher luminance, it is suitable for a target mark having a semi-transparent resist film, and the gradation width at the time of image recognition can be increased. effective.

  FIG. 4 relates to Example 4 showing an image recognition surface light source device 40 used for a large area exposure table, 41 is an electroluminescent sheet which is a large area surface light source, 42 is an insulating case, and 43 is an electric cord. , 44 indicates a rectangular frame which is a surface light source mounting base material. Example 4 is used for large image recognition such as a printed circuit board inspection device, and projects a target image that is not covered by the surface light source devices 10, 20, and 30 of Examples 1 to 3 onto a target. Suitable for doing. The surface light source device 40 of Example 4 can be formed by using an electroluminescence sheet, and an electroluminescent material in which a phosphor is dispersed in a high dielectric constant binder as in Example 3 is used for sputtering. A method of forming a film on the substrate surface by a film forming means may be used.

  In the present invention, a target image such as a desired image pattern can be projected onto a target 16 by parallel light rays based on the surface light source devices 10, 20, 30, and 40 as illustrated, and image recognition can be performed. The specific forms of the surface light source devices 10, 20, 30, 40 themselves can be arbitrarily determined, and the electroluminescent sheet is used not only in terms of shape but also in structure, or a film forming component that exhibits an electroluminescent function Thus, it is possible to freely select whether to form a film.

(A) The front view of Example 1 which shows embodiment of the surface light source device for image recognition which concerns on this invention. (B) Similarly side view. (A) The front view of Example 2 similarly. (B) Similarly side view. (A) The front view of Example 3 similarly. (B) The perspective view similarly seen from the side. (A) The front view of Example 4 similarly. (B) Similarly side view. Explanatory drawing of the exposure apparatus of the transmission illumination system to which this invention is applied. Explanatory drawing of the exposure apparatus of the reflective illumination system to which this invention is applied. (A) The schematic diagram which shows the example of the image formation by a point light source. (B) The figure which shows the example 1 of image formation by a point light source. (C) The figure which shows the example 2 of the image formation by a point light source. (A) The schematic diagram which shows the example of the image formation by this invention. (B) The figure which shows Example 1 of the image formation by this invention. (C) The figure which shows the example 2 of the image formation by this invention.

Explanation of symbols

10, 20, 30, 40 Surface light source device 11, 21, 41 Electroluminescent sheet as surface light source 12, 22, 32, 42 Insulating case 13, 23, 33, 43 Electric cord 14, 24, 34, 44 Mounting base Frame 15 or 15 'as a material Work target mark as a target image 16 CCD as a target object
25, 35 Opening 31 Surface light source that exhibits electroluminescence function

Claims (3)

When manufacturing or inspecting power elements including diodes, power transistors, or elements including printed wiring circuit boards and liquid crystal panels, to project the target image on the surface of the target or project the target image onto the inspection device In the light source device used for capturing by the light source, a surface having a size that covers the entire target image and exerting an electroluminescence function in order to project a desired image pattern onto the target by parallel rays It is composed of a surface light source composed of a light emitting part and a frame which is a surface light source mounting base formed substantially in the same shape as the surface light source to support the surface light source, and the surface light source is provided integrally with the frame. A characteristic surface light source device for image recognition. The surface light emitting unit that exhibits the electroluminescence function has a structure in which a surface electrode including a light emitting layer and a back electrode are arranged with an insulating layer interposed therebetween, and an AC voltage is applied to both the electrodes via an inverter, 2. The surface light source device for image recognition according to claim 1, wherein the light emitting layer is an electroluminescent sheet in which a phosphor is dispersed in a high dielectric constant binder. The surface light emitting portion that exhibits the electroluminescence function is formed in a film shape by a film forming means such as a sputtering method or a printing method on the surface light emitting portion in which the phosphor is dispersed in the high dielectric constant binder. Item 2. A surface light source device for image recognition according to Item 1.

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