Light path structure and optical detection equipment with same

Abstract

The utility model discloses a light path structure and optical detection equipment with the same, and the light path structure comprises a first side light source device which emits visible light to an objective table at a first inclination angle; the second side light source device emits ultraviolet light to the objective table at a second inclination angle larger than the first inclination angle; the combined light source device is provided with a white light source, an ultraviolet light source and an optical assembly, and the optical assembly enables optical axes, emitted from the combined light source device, of the white light source and the ultraviolet light source to be parallel or coincide; and the first optical element is arranged on the light emitting path of the combined light source device and is configured to convert the light emitting direction of the first optical element to form a third inclination angle with the plane where the objective table is located, and the third inclination angle is larger than the second inclination angle. The utility model provides an improved multi-band and multi-angle light inlet light source combination, the light inlet angle of ultraviolet light is improved, the problem that the light inlet amount of the ultraviolet light is insufficient is solved, and the image effect of optical detection equipment is improved.

Description

Technical Field

[0001] This utility model relates to the field of optical inspection, and in particular to an optical path structure and an optical inspection device having the same. Background Technology

[0002] Automated optical inspection is a device that uses optical principles to detect common defects encountered during the manufacturing process of PCB circuit boards or IC substrates.

[0003] During the inspection process, a light source is needed to illuminate the object under test (such as a PCB or IC substrate) in order to optimize the imaging results; the design of the light source has a significant impact on the accuracy of AOI inspection.

[0004] Currently, most PCB optical inspection equipment on the market uses a video image acquisition device consisting of a high-definition area scan camera, a zoom light tube, a high-magnification lens, and a multi-angle light source. The light source is usually a single, ordinary white light source. Different magnifications and light source distributions are customized according to the precision of the object being tested (PCB / IC substrate). This device can effectively meet the needs of image acquisition and recognition for PCB circuit boards with low precision and circuit defects mostly larger than 15 micrometers.

[0005] For example, Chinese patent with publication number CN216747477U discloses, for instance, Figure 8 The optical path design shown will cause the PCB's copper foil traces to change from bright field to dark field (black) under UV light mode, while the substrate will change from dark field to fluorescent color. (See attached image.) Figures 9 to 10 The transformation, under this imaging effect, allows for better differentiation of defects in PCB circuitry. However, observation... Figure 10 It can be observed that a third color, between fluorescent and dark black, appears in the gaps between the tiny copper foil lines. This can interfere with optical inspection and affect the accuracy of defect detection.

[0006] The above background information is provided only to aid in understanding the concept and technical solution of this application. It does not necessarily belong to the prior art of this application, nor does it necessarily provide technical guidance. In the absence of clear evidence that the above information was disclosed before the filing date of this application, the above background information should not be used to evaluate the novelty and inventiveness of this application. Utility Model Content

[0007] The purpose of this invention is to provide an improved combination of multi-band, multi-angle light sources to enhance the imaging effect of optical inspection equipment.

[0008] To achieve the above objectives, the technical solution adopted by this utility model is as follows:

[0009] An optical path structure is disposed above a stage, the optical path structure comprising:

[0010] A first side light source device is configured with a plurality of first white light sources, and the first side light source device emits light toward the stage at a first tilt angle;

[0011] The second side light source device is equipped with multiple first ultraviolet light sources. The second side light source device emits light toward the stage at a second tilt angle, which is greater than the first tilt angle.

[0012] A combined light source device is configured with a second white light source, a second ultraviolet light source, and an optical component, wherein the optical component is configured such that the optical axes emitted from the second white light source and the second ultraviolet light source from the combined light source device are parallel or coincident.

[0013] A first optical element is disposed in the light output path of the combined light source device and configured to change its light output direction to form a third tilt angle with the plane of the stage, the third tilt angle being greater than the second tilt angle.

[0014] Furthermore, following any of the aforementioned technical solutions or combinations thereof, the light spots incident on the stage by the first side light source device, the second side light source device, and the combined light source device overlap or are adjacent.

[0015] Furthermore, in accordance with any or a combination of the aforementioned technical solutions, the optical path structure provided in this embodiment of the present invention further includes a third side light source device, which is configured with a plurality of third white light sources. The third side light source device emits light toward the stage at a fourth tilt angle, the fourth tilt angle being between the second tilt angle and the third tilt angle.

[0016] Furthermore, following any one or a combination of the aforementioned technical solutions, the number of the combined light source devices is one, and the light emitted from the combined light source device is reflected by the first optical element and then directed perpendicularly toward the stage.

[0017] Furthermore, following any one or a combination of the aforementioned technical solutions, the number of the combined light source devices is multiple, and the multiple combined light source devices are equally distributed in a circular pattern.

[0018] Furthermore, based on any or a combination of the aforementioned technical solutions, the optical component includes a first reflecting mirror and a first beam splitter, wherein the first reflecting mirror is disposed in the light output path of the second white light source;

[0019] The first beam splitter is disposed in the light output path of the second ultraviolet light source and in the light path emitted from the second white light source and reflected by the first reflector.

[0020] The first beam splitter has a transmittance of 75% for visible light and a reflectance of 75% for ultraviolet light.

[0021] Furthermore, in accordance with any or a combination of the aforementioned technical solutions, the optical component further includes a condenser lens and / or a first filter disposed between the second ultraviolet light source and the first beam splitter, wherein the condenser lens is configured as a convex lens or a plano-convex lens, and the filtering wavelength range of the first filter is between 10 nm and 380 nm.

[0022] Furthermore, based on any one or a combination of the aforementioned technical solutions, the light transmission wavelength range of the first beam splitter is between 381 nm and 780 nm.

[0023] According to another aspect of the present invention, the present invention provides an optical inspection device, including a camera module and an optical path structure as described above, wherein the lens of the camera module is configured to receive light reflected from the stage.

[0024] Furthermore, based on any or a combination of the aforementioned technical solutions, the camera module further includes a focus fine-tuning unit, a zoom unit, and an image sensor, wherein the image sensor is a CCD sensor or a CMOS sensor, and the zoom unit includes a zoom drive motor and a zoom light tube.

[0025] The beneficial effects of the technical solution provided by this utility model are as follows:

[0026] a. A new optical path was designed to improve the angle of ultraviolet (UV) light intake, thereby addressing the problem of insufficient UV light intake and enhancing the image quality under UV light when capturing even the smallest line defects on high-end circuit boards.

[0027] b. Improve the direct light source to a visible / ultraviolet combined direct light source with a compact structure. It can use a separate control type to trigger different channels of visible light source and / or ultraviolet light source according to actual detection needs. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 A front view of an optical detection device provided as an exemplary embodiment of the present invention;

[0030] Figure 2 A bottom view of an optical detection device provided as an exemplary embodiment of the present invention;

[0031] Figure 3 for Figure 1 A schematic diagram of the modular light source device;

[0032] Figure 4 for Figure 3 A schematic diagram of the split-type second ultraviolet light source;

[0033] Figure 5 A schematic diagram of the optical path structure of an optical detection device provided as an exemplary embodiment of the present invention;

[0034] Figure 6 This is a generalized optical image of the object being inspected by the optical inspection device in this embodiment of the invention.

[0035] Figure 7 This is an ultraviolet light image of the object being tested formed by the optical detection device in this embodiment of the invention;

[0036] Figure 8 This is a schematic diagram of the optical path structure of the optical inspection equipment before the improvement.

[0037] Figure 9 The general optical image of the object being inspected by the optical inspection equipment before the improvement;

[0038] Figure 10 The image is an ultraviolet light image of the object being inspected obtained by the optical inspection equipment before the improvement.

[0039] The reference numerals in the accompanying drawings include: 110-first white light source, 210-first ultraviolet light source, 310-third white light source, 400-stage, 500-combined light source device, 510-second white light source, 520-second ultraviolet light source, 521-heat sink, 530-optical component, 5301-first reflector, 5302-first beam splitter, 5303-condenser lens, 5304-first filter, 5305-light output adapter, 540-first optical element, 610-lens, 620-focusing fine-tuning unit, 630-image sensor, 640-zoom drive motor, 650-zoom light tube, 660-second filter. Detailed Implementation

[0040] In order to help those skilled in the art better understand the present invention, the following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0041] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this utility model are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the utility model described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, apparatus, product, or device that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or devices.

[0042] In one embodiment of this utility model, an optical path structure is provided, see [link to relevant documentation]. Figure 5 and Figure 1 The optical path structure is positioned above the stage 400. The optical path structure includes a first-side light source device, a second-side light source device, a combined light source device 500, and a first optical element 540. The following is a detailed description of each component:

[0043] The first side light source device is equipped with a plurality of first white light sources 110, and the first side light source device emits light toward the stage 400 at a first tilt angle; such as Figure 1 and Figure 2 As shown, each first side light source device is equipped with a substrate and multiple first white light sources 110 distributed on the substrate. Multiple substrates are distributed on a ring-shaped member, preferably at equal intervals, so that the multiple first side light source devices can provide good uniformity of illumination on the target position on the stage 400.

[0044] The second side light source device is equipped with multiple first ultraviolet light sources 210, including selectable 405nm UV spotlights. The second side light source device emits light onto the stage 400 at a second tilt angle, where the second tilt angle is greater than the first tilt angle; similarly, as Figure 2As shown, the three first ultraviolet light sources 210 are preferably distributed at equal intervals, which ensures good uniformity in illuminating the target position on the stage 400 by the second side light source device. Here, the tilt angle is defined as the angle between the optical axis of the light ray and the plane containing the stage 400. It should be noted that the present invention does not limit the number of first ultraviolet light sources 210 to three. Figure 2 The quantities and locations shown are for illustrative purposes only.

[0045] The combined light source device 500 is equipped with a second white light source 510, a second ultraviolet light source 520, and an optical component 530, such as... Figure 5 As shown, the optical component 530 is configured such that the optical axes of the second white light source 510 and the second ultraviolet light source 520 emitted from the combined light source device 500 are parallel or coincident. The second ultraviolet light source 520 may be a 405nm UV lamp, which is equipped with a heat sink 521. Specifically, as shown... Figure 3 and Figure 5 As shown, the optical component 530 includes a first reflecting mirror 5301 and a first beam splitter 5302. The first reflecting mirror 5301 is disposed in the light-emitting path of the second white light source 510; the first beam splitter 5302 is disposed in the light-emitting path of the second ultraviolet light source 520, and is also disposed in the light path emitted from the second white light source 510 and reflected by the first reflecting mirror 5301. The first beam splitter 5302 needs to be selected within a specific wavelength range to maximize the transmission of visible light and maximize the reflection of ultraviolet light, thus enabling… The light emitted downward from the second white light source 510 is reflected by the first reflecting mirror 5301 and then passes horizontally through the first beam splitter 5302. The light emitted downward from the second ultraviolet light source 520 is reflected by the first beam splitter 5302 and also propagates horizontally. In a specific embodiment, the first beam splitter 5302 has a transmittance of 75% for visible light and a reflectance of 75% for ultraviolet light. In another specific embodiment, the wavelength range of the first beam splitter 5302 is between 381nm and 780nm.

[0046] Furthermore, the optical component 530 also includes a condenser lens 5303 and / or a first filter 5304 disposed between the second ultraviolet light source 520 and the first beam splitter 5302. The condenser lens 5303 is configured as a convex lens or a plano-convex lens, which is used to improve the light concentration of the ultraviolet light. The illuminance of the ultraviolet spot light can typically reach 2500 mw / cm². 2The ultraviolet spot light after passing through the condenser lens 5303 has strong focusing and penetrating properties, which can provide sufficient light for the camera to capture tiny defects; the first filter 5304 has a filtering wavelength range between 10nm and 380nm, which is used to filter stray light to improve the purity of ultraviolet light output, and the first filter 5304 can be a BP405 filter.

[0047] The first optical element 540 is disposed in the light output path of the combined light source device 500 and is configured to change its light output direction to form a third tilt angle with the plane of the stage 400, the third tilt angle being greater than the second tilt angle. In a specific embodiment, the third tilt angle is 90°.

[0048] like Figure 5 As shown, the light spots incident on the stage 400 by the first side light source device, the second side light source device, and the combined light source device 500 overlap or are adjacent.

[0049] In a specific embodiment, such as Figure 1 , Figure 2 and Figure 5 As shown, the optical path structure provided in this embodiment of the present invention further includes a third-side light source device, which is configured with a plurality of third white light sources 310. The third-side light source device emits light towards the stage 400 at a fourth tilt angle, the fourth tilt angle being between the second tilt angle and the third tilt angle. See also Figure 2 Each third-side light source device is equipped with a substrate and multiple third white light sources 310 distributed on the substrate. The multiple substrates are preferably distributed at equal intervals, so that the multiple third-side light source devices can provide good balance in illuminating the target position on the stage 400.

[0050] In this embodiment, the number of the combined light source device 500 is one. The light emitted from the combined light source device 500 is reflected by the first optical element 540 and then directed perpendicularly towards the stage 400, i.e., the third tilt angle is 90°. In this case, the combined light source device 500 is defined as a direct light source, which compensates for the problem of incomplete side ultraviolet light coverage. However, the present invention does not limit the number of combined light source devices. In other embodiments, the number of combined light source devices 500 is multiple, and the multiple combined light source devices 500 are equally distributed in a circular pattern, so that the illumination of the target position on the stage 400 by the multiple combined light source devices 500 has good uniformity.

[0051] In one embodiment of this utility model, an optical detection device is provided, such as... Figure 1 and Figure 2As shown, the device includes a camera module and the optical path structure described above. The lens 610 of the camera module is configured to receive light reflected from the stage 400. The combined light source device 500 is connected to the optical inspection device via a light output adapter 5305. The first side light source device, the second side light source device, and the third side light source device are mounted on the optical inspection device via a ring-shaped bracket.

[0052] Specifically, the camera module further includes a focus fine-tuning unit 620, a zoom unit, a second filter 660, and an image sensor 630. The image sensor 630 is a CCD sensor, a CMOS sensor, or other high-definition dot-matrix or area-matrix camera. The zoom unit includes a zoom drive motor 640 and a zoom light tube 650. To shorten the length of the optical detection equipment, a second beam splitter or a second reflector can be used to form a shape such as... Figure 5 The L-shaped imaging optical path is shown.

[0053] The above-mentioned optical path is the illumination optical path. In the optical inspection equipment, light shines on the object to be inspected on the stage 400. The light reflected from the object to be inspected enters the lens 610 from bottom to top, and then passes through the first optical element 540, and sequentially passes through the focusing fine adjustment unit 620, the zoom unit, the second filter 660, and the image sensor 630 to form the imaging optical path.

[0054] The system employs a distributed control approach, allowing independent control of the first, second, and third side light source devices and the combined light source device 500. It also allows for distributed control of one of the second white light source 510 and the second ultraviolet light source 520 within the combined light source device 500, while the other is turned off. This enables the camera module to obtain an image when the second white light source 510 in the first, third, and combined light source devices 500 is turned on. Figure 6 The image shown is a generalized optical image of the object being inspected; when the second ultraviolet light source 520 in the second side light source device and the combined light source device 500 is turned on, the camera module obtains an image as shown below. Figure 7 The image shown is an ultraviolet image of the object being detected. Figure 7 and Figure 10 As can be seen from the comparison, the optical inspection equipment using the optical path structure of this utility model has significantly improved the PCB circuit image under ultraviolet light. That is, no third color between fluorescent color and dark field black appears in the ultraviolet image, which is particularly beneficial for detecting tiny defects of less than 15 micrometers or even about 5 micrometers on high-end circuit boards.

[0055] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply the existence of any such actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article, or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or device. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of other identical elements in the process, method, article, or device comprising the element.

[0056] The above description is only a specific embodiment of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this application, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. An optical path structure disposed above a stage (400), characterized in that, The optical path structure includes: A first side light source device is provided with a plurality of first white light sources (110), and the first side light source device emits light toward the stage (400) at a first tilt angle; The second side light source device is equipped with a plurality of first ultraviolet light sources (210). The second side light source device emits light toward the stage (400) at a second tilt angle, the second tilt angle being greater than the first tilt angle. A combined light source device (500) is configured with a second white light source (510), a second ultraviolet light source (520), and an optical component (530), wherein the optical component (530) is configured such that the optical axes of the second white light source (510) and the second ultraviolet light source (520) emitted from the combined light source device (500) are parallel or coincident. A first optical element (540) is disposed in the light output path of the combined light source device (500) and configured to change its light output direction to form a third tilt angle with the plane of the stage (400), the third tilt angle being greater than the second tilt angle.

2. The optical path structure according to claim 1, characterized in that, The light spots incident on the stage (400) by the first side light source device, the second side light source device, and the combined light source device (500) overlap or are adjacent.

3. The optical path structure according to claim 1, characterized in that, It also includes a third side light source device, which is equipped with a plurality of third white light sources (310), the third side light source device emitting light toward the stage (400) at a fourth tilt angle, the fourth tilt angle being between the second tilt angle and the third tilt angle.

4. The optical path structure according to claim 1, characterized in that, The number of the combined light source device (500) is one, and the light emitted by the combined light source device (500) is reflected by the first optical element (540) and then directed vertically toward the stage (400).

5. The optical path structure according to claim 1, characterized in that, The number of the combined light source devices (500) is multiple, and the multiple combined light source devices (500) are equally distributed in a circular pattern.

6. The optical path structure according to claim 1, characterized in that, The optical component (530) includes a first reflector (5301) and a first beam splitter (5302), wherein the first reflector (5301) is disposed in the light output path of the second white light source (510); The first beam splitter (5302) is disposed in the light output path of the second ultraviolet light source (520) and in the light path emitted from the second white light source (510) and reflected by the first reflector (5301); The first beam splitter (5302) has a transmittance of 75% for visible light and a reflectance of 75% for ultraviolet light.

7. The optical path structure according to claim 6, characterized in that, The optical component (530) further includes a condenser lens (5303) and / or a first filter (5304) disposed between the second ultraviolet light source (520) and the first beam splitter (5302), wherein the condenser lens (5303) is configured as a convex lens or a plano-convex lens, and the first filter (5304) has a filtering wavelength range between 10 nm and 380 nm.

8. The optical path structure according to claim 6, characterized in that, The light transmission wavelength range of the first beam splitter (5302) is between 381nm and 780nm.

9. An optical inspection device, characterized in that, Includes a camera module and an optical path structure as described in any one of claims 1 to 8, wherein the lens (610) of the camera module is configured to receive light reflected from the stage (400).

10. The optical inspection device according to claim 9, characterized in that, The camera module also includes a focus fine-tuning unit (620), a zoom unit, and an image sensor (630). The image sensor (630) is a CCD sensor or a CMOS sensor. The zoom unit includes a zoom drive motor (640) and a zoom light tube (650).

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