TW202104877A - Micro particle inspection apparatus - Google Patents

Abstract

A micro particle inspection apparatus adapted to detect a plurality of micro particles of a target object is provided. The micro particle inspection apparatus includes a light source, an optical system and an image capturing device. The light source is adapted to provide an illumination beam. The optical system is disposed on the transmission path of the illumination beam. The optical system includes an optical focusing element having a depth of field value. The optical system provides a detection beam onto the target object to produce an image beam. The image capturing device is disposed on the transmission path of the image beam, wherein the detecting beam is a collimated light beam, and a focal plane of the optical focusing element does not overlap with a surface of the target object having the micro particles.

Description

Microparticle detection device

The present invention relates to a lighting device, and more particularly to a particle detection device.

With the development of science and technology, people have higher and higher demands for the precision and quality of electronic components in electronic products. For example, the quality and appearance inspection of various components on a circuit board in an electronic product is an important step in the manufacturing and inspection process to ensure that the circuit board functions normally. In the current manufacturing process of circuit boards, there is a step of bonding copper foil substrates after applying conductive particle paste. Therefore, in order to have a good manufacturing process for the circuit board, it is necessary to observe the structure of tiny conductive particles with inspection equipment during or after the manufacturing process to calculate the density of conductive particles.

However, in the current practice, a differential interference contrast (DIC) microscope module is often used on the end of the optical inspection device that is closer to the objective lens to observe the conductive particles. However, if this method is used, it will not only need to configure more optical components, but will also further increase the cost. In addition, adding optical elements will also cause the overall brightness of the illumination to be reduced by more than half. Therefore, if a good optical effect is to be achieved, the illumination brightness needs to be further increased. Furthermore, the optical inspection equipment using the differential interference phase contrast microscope module has more complicated operating procedures. Therefore, how to design or improve the existing optical inspection equipment without additional configuration of a differential interference phase contrast microscope module to increase the contrast presented by the microparticles is a joint study by those skilled in the art.

The present invention provides a microparticle detection device, which can improve the contrast of microparticles in an image.

An embodiment of the present invention provides a particle detection device for detecting multiple particles of a target object. The particle detection device includes a light source, an optical system, and an image capture device. The light source is suitable for providing an illumination beam. The optical system is arranged on the transmission path of the illumination beam. The optical system includes an optical focusing element with a depth of field value. The optical system provides a detection beam to the target object to generate an image beam. The image capturing device is arranged on the transmission path of the image beam, and a focal plane of the optical focusing element does not overlap with a surface of the target object with particles.

In an embodiment of the present invention, the above-mentioned particle detection device further includes an adjustment module. The light source is arranged on the adjustment module, and the adjustment module is suitable for moving the light source to change the distance between the light source and the optical system.

In an embodiment of the present invention, the distance between the focal plane of the above-mentioned optical focusing element and the surface of the target object with particles is between a quarter of the depth of field value to twice the depth of field value.

In an embodiment of the present invention, the above-mentioned optical system further includes a defocusing module. The optical focusing element is disposed on the defocusing module, and the defocusing module is suitable for moving the optical focusing element to make the optical focusing element slightly defocus the target object.

In an embodiment of the present invention, the illumination beam provided by the above-mentioned light source is a collimated beam.

In an embodiment of the present invention, the above-mentioned light source is a point light source.

In an embodiment of the present invention, the above-mentioned particle detection device further includes a processing unit, which is electrically connected to the image capture device, and is suitable for analyzing the target object according to the image capture device.

In an embodiment of the present invention, the above-mentioned particle detection device further includes a moving stage adapted to carry the target object, and the moving stage is adapted to move the target object to make the optical focusing element slightly defocus the target object.

In an embodiment of the present invention, the above-mentioned optical system is a reflective optical system.

In an embodiment of the present invention, the above-mentioned fine particles of the target object are charged particles.

In an embodiment of the present invention, the aforementioned detection beam is a collimated beam.

Based on the above, the microparticle detection device of the present invention can project a detection beam with collimation characteristics onto the surface of the target object with microparticles, and generate microparticles by an optical focusing element as an objective lens in the optical system. The out-of-focus state improves the image contrast of the multiple particles on the target object presented by the image capturing device, so that it has a good optical display effect, and then the unit density of the particles on the target object can be detected.

In order to make the above-mentioned features and advantages of the present invention more comprehensible, the following specific embodiments are described in detail in conjunction with the accompanying drawings.

FIG. 1 is a schematic diagram of a fine particle detection device according to an embodiment of the present invention. Please refer to Figure 1. This embodiment provides a fine particle detection device 100 for detecting a plurality of fine particles P of a target object 10. For example, the target object 10 is, for example, a circuit board, and the plurality of particles P are, for example, conductive particles on the circuit board. However, the particle detection device 100 can actually be applied to detect different types of protruding particles, and the present invention is not limited to this.

The particle detection device 100 includes a light source 110, an optical system 120, and an image capturing device 130. Specifically, in this embodiment, the fine particle detection device 100 further includes a processing unit 140. The light source 110 is suitable for providing an illumination beam L1 to the optical system 120. The light source 110 is, for example, a halogen lamp, a visible light laser device, an infrared laser device, or a light-emitting diode light source. The illuminating light beam L1 can be white light, single-wavelength visible light, near-infrared light, short-wavelength infrared light, or other wavelength light. It is not limited to this.

The optical system 120 is, for example, an optical lens or an optical device having a combination of components such as a focusing lens, a reflecting mirror, a beam splitter, or other optical elements. In this embodiment, the optical system 120 is a reflective optical system. The optical system 120 is adapted to receive the illumination light beam L1 provided by the light source 110, and through the optical action of the optical elements inside the optical system 120 to provide a detection light beam L2 to the target object 10 to generate an image light beam L3 and transmit it to the optics In the system 120, the detection beam L2 transmitted to the target object 10 is a collimated beam or a beam with collimating characteristics. In this embodiment, the illumination light beam L1 provided by the light source 110 is a collimated light beam. However, in different embodiments, the detection beam L2 can be substantially the same as or different from the illumination beam L1, for example, the non-collimated illumination beam L1 is converted into a detection beam with collimation characteristics by the optical effect of the optical system 120 L2, the present invention does not stop there.

In detail, the optical system 120 includes an optical focusing element 122, such as an objective lens, and the optical focusing element 122 has a depth of field value. In this embodiment, a focal plane of the optical focusing element 122 does not overlap with a surface of the target object 10 having the particles P. In other words, the optical focusing element 122 is in a slightly defocused state with respect to the surface of the target object 10 with the particles P. In this embodiment, the distance between the focal plane of the optical focusing element 122 and the surface of the target object 10 with the particles P is between a quarter of the depth of field value of the optical focusing element 122 to twice the depth of field value of the optical focusing element 122 between.

The image capturing device 130 is disposed on the transmission path of the image beam LI, and is adapted to receive the image beam LI, and convert the optical image of the image beam LI into an electronic signal. Specifically, the infrared image capturing device 130 includes a photosensitive element 132, which is adapted to receive the image beam LI to convert it into an image information. The photosensitive element 132 is, for example, a charge-coupled device (CCD). In this embodiment, the image capturing device 130 is, for example, a line scan camera or an area scan camera. In some embodiments, the image capture device 130 can be configured with one or more optical lens combinations with diopters according to requirements, such as non-planar lenses including biconcave lenses, biconvex lenses, meniscus lenses, convex-concave lenses, plano-convex lenses, and plano-concave lenses. Various combinations are used to help guide the image beam LI, but the invention is not limited to this. The processing unit 140 is electrically connected to the image capturing device 130, and is adapted to analyze the target object 10 according to the image information converted by the photosensitive element 132.

Therefore, during detection, the microparticle detection device 100 can project the detection beam L2 with collimation characteristics onto the surface of the target object 10 with the microparticles P, and use an optical focusing element in the optical system 120 as an objective lens. 122 generates a slight defocus to increase the image contrast of the particles P on the target object 10 presented by the image capturing device 130, so that it has a good optical display effect, and then the unit density of the particles P on the target object 10 can be detected.

Fig. 2 is a schematic diagram of a fine particle detection device according to another embodiment of the present invention. Please refer to Figure 2. The fine particle detection device 100A of this embodiment is similar to the fine particle detection device 100 shown in FIG. 1. The difference between the two is that, in this embodiment, the particle detection device 100A further includes an adjustment module 150, which is suitable for disposing the light source 110 therein, so that the adjustment module 150 moves the light source 110 to change the light source 110 and the optical system 120 distance. In detail, in this embodiment, the adjustment module 150 has, for example, a structure for accommodating and fixing the light source 110 and a track or other mechanism suitable for moving the structure back and forth along the direction D1. In this way, by moving the light source 110 farther (for example, moving to a farther position 110'), the contrast can be further improved to obtain a clearer image of the particles P. In addition, since the distance between the light source 110 and the optical system 120 can be adjusted, the light source 110 of this embodiment can be a point light source.

FIG. 3 is a schematic diagram of a fine particle detection device according to another embodiment of the present invention. Please refer to Figure 3. The particle detection device 100B of this embodiment is similar to the particle detection device 100A shown in FIG. 2. The difference between the two is that in this embodiment, the optical system 120 of the particle detection device 100B further includes a defocusing module 124. The optical focusing element 122 is disposed on the defocusing module 124, and the defocusing module 124 is adapted to move the optical focusing element 122 to cause the optical focusing element 122 to slightly defocus the target object 10. In other words, compared with the above-mentioned embodiment, this embodiment can achieve a slightly defocused state by changing the position of the optical focusing element 122. In addition, in the case of non-detecting microparticles P, the microparticle detection device 100B can also move the optical focusing element 122 to the focused state by operating the defocus module 124, thereby making the microparticle detection device 100B operability in different applications .

FIG. 4 is a schematic diagram of a fine particle detection device according to another embodiment of the present invention. Please refer to Figure 4. The particle detection device 100C of this embodiment is similar to the particle detection device 100A shown in FIG. 2. The difference between the two is that, in this embodiment, the particle detection device 100C further includes a movable stage 160 suitable for carrying the target object 10. The moving stage 160 is adapted to move the target object 10 so that the optical focusing element 122 slightly defocuss the target object 10. In other words, compared with the above-mentioned embodiment, this embodiment can achieve a slightly defocused state by changing the position of the target object 10. In addition, in the case of non-detecting microparticles P, the microparticle detection device 100B can also move the target object 10 to the focused state by operating the stage 160, so that the microparticle detection device 100B has operability in different applications.

In summary, the microparticle detection device of the present invention can be used to project a detection beam with collimation characteristics onto the surface of the target object with microparticles, and by an optical focusing element as the objective lens in the optical system. Produces a slightly defocused state, improves the image contrast of the multiple particles on the target object presented by the image capturing device, so that it has a good optical display effect, and can detect the unit density of the particles on the target object.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the present invention. Anyone with ordinary knowledge in the relevant technical field can make some changes and modifications without departing from the spirit and scope of the present invention. The scope of protection of the present invention shall be determined by the scope of the attached patent application.

10: Target object 100, 100A, 100B, 100C: fine particle detection device 110: light source 110’: Location 120: optical system 122: Optical focusing element 124: Defocus module 130: Image capture device 132: photosensitive element 140: processing unit 150: adjustment module 160: mobile carrier D1: direction L1: Illuminating beam L2: Detection beam L3: image beam P: fine particles

FIG. 1 is a schematic diagram of a fine particle detection device according to an embodiment of the present invention. Fig. 2 is a schematic diagram of a fine particle detection device according to another embodiment of the present invention. FIG. 3 is a schematic diagram of a fine particle detection device according to another embodiment of the present invention. FIG. 4 is a schematic diagram of a fine particle detection device according to another embodiment of the present invention.

10: Target object

100: Microparticle detection device

110: light source

120: optical system

122: Optical focusing element

130: Image capture device

132: photosensitive element

140: processing unit

L1: Illuminating beam

L2: Detection beam

L3: image beam

P: fine particles

Claims (11)

A fine particle detection device, used for detecting a plurality of fine particles of a target object, includes: A light source, suitable for providing an illumination beam; An optical system configured on the transmission path of the illumination beam, the optical system including an optical focusing element having a depth of field value, the optical system providing a detection beam to the target object to generate an image beam; and An image capturing device is arranged on the transmission path of the image beam, and a focal plane of the optical focusing element does not overlap with a surface of the target object with the particles. The fine particle detection device described in item 1 of the scope of patent application also includes: An adjustment module, the light source is arranged on the adjustment module, and the adjustment module is adapted to move the light source to change the distance between the light source and the optical system. The fine particle detection device according to claim 1, wherein the distance between the focal plane of the optical focusing element and the surface of the target object with the fine particles is within a quarter of the depth of field value to two Times the depth of field value. The fine particle detection device according to claim 1, wherein the optical system further includes a defocusing module, the optical focusing element is disposed on the defocusing module, and the defocusing module is suitable for moving the optical focus Element to make the optical focusing element slightly defocus the target object. As described in the first item of the scope of patent application, the illuminating light beam provided by the light source is a collimated light beam. In the fine particle detection device described in item 1 of the scope of patent application, the light source is a point light source. The fine particle detection device described in item 1 of the scope of patent application also includes: A processing unit is electrically connected to the image capture device, and is suitable for analyzing the target object according to the image capture device. The fine particle detection device described in item 1 of the scope of patent application also includes: A moving stage is suitable for carrying the target object, and the moving stage is suitable for moving the target object to make the optical focusing element slightly defocus the target object. In the fine particle detection device described in item 1 of the scope of patent application, the optical system is a reflective optical system. According to the fine particle detection device described in item 1 of the scope of patent application, the fine particles of the target object are charged particles. As described in the first item of the scope of patent application, the detection device for particles, wherein the detection beam is a collimated beam.

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