TW202104873A - System and method for inspecting objects based on polarization property - Google Patents

Abstract

A system for inspecting an object, the system comprises: a sensing module that comprises multiple collection paths, each collection path comprises a camera and an analyzer that defines a polarization property of the collection path; a controller that is configured to set polarization properties of the multiple collection paths independently from each other; a beam splitter; an objective lens; an illumination module that is configured to (a) direct a bright field beam towards an area of the object at a first angular range; (b) direct a first dark field beam towards the area of the object at a second angular range; (c) direct a second dark field beam towards the area of the object at a third angular range; (d) direct, towards the sensing module, at least one specular reflectance from at least one beam out of the bright field beam, the first dark field beam and the second dark field beam.

Description

System and method for inspecting objects based on polarization characteristics

Related application

This application is a divisional application of the Taiwan patent application with the application number 104142465, and all the above-mentioned patents are incorporated herein by reference.

The present invention relates to enhanced optical inspection using polarization imaging.

Background of the invention

In uneven objects including portions with angled surfaces such as PCB layers whose copper signal lines have a trapezoidal profile, the prior art method is not arranged to collect specular reflections from all surface angles.

In addition, some of the known methods of analyzing the reflection polarization state are only effective when the incident angle is significantly different from the normal angle. Therefore, brightfield or coaxial light parallel to the imaging axis and perpendicular to the flat panel being inspected is not available.

Furthermore, some inspection methods require additional setup procedures to set the optimized polarizer/analyzer orientation. Still further, some of the methods require the capture of multiple images, each with a different polarizer/analyzer orientation.

Therefore, in the context of inspecting uneven objects, there is a need to provide systems and methods that realize the collection of specular reflections from a wide range of surface angles, and make the incident angle not the normal angle, but rather close to the Brewster angle. In addition, these methods will benefit from the ability to capture multiple images in one channel at the same time with different polarization orientations.

Summary of the invention

According to various embodiments of the present invention, systems and methods may be provided.

The system can be used to inspect an object. The system can include a sensing module, which can include multiple collection paths, each collection path can include a camera and an analyzer that defines the polarization characteristics of the collection path; a controller, which can be configured to each other Independently set the polarization characteristics of the multiple collection paths; beam splitter; objective lens; illumination module, which can be configured to (a) direct the bright field light beam to the area of the object in a first angle range; (b) direct the first dark The field beam is directed to the area of the object in the second angular range; (c) the second dark field beam is directed to the area of the object in the third angle range; (d) the light beam from the bright field, the first dark field beam and the second dark field At least one specular reflection of at least one of the light beams is guided to the sensing module.

The lighting module may be configured to direct the specular reflection of the bright field beam to the sensing module when the area of the object may include a region with a first orientation; when the area of the object may include a region with a second orientation, the first The specular reflection of a dark field beam is directed to the sensing module; and when the area of the object may include a region with a third orientation, the specular reflection of the second dark field beam is directed to the sensing module; wherein, the first orientation, The second orientation and the third orientation are different from each other.

The controller may be configured to set the polarization characteristics of the plurality of collection paths so that during a given point in time, the polarization characteristics of the first collection path are different from the polarization characteristics of the second collection path.

The lighting module may not include any polarizers.

The lighting module may include at least one polarizer, which may be associated with at least one of the bright field light beam, the first dark field light beam, and the second dark field light beam.

The lighting module may include a bright field light source, which may be followed by a blocking element, and the blocking element may be configured to block the bright field beam from irradiating the third area of the beam splitter.

The lighting module may also be configured to illuminate the second area of the beam splitter with a second bright field beam; wherein the second area of the beam splitter may be configured to direct the second bright field beam to the second area of the objective lens; wherein The second area of the objective lens may be configured to direct the second bright field light beam to the object so as to irradiate the object with a third angle range different from the first angle range and the second angle range.

The illumination module may also be configured to illuminate the fourth area of the beam splitter with the third bright field beam; wherein the fourth area of the beam splitter may be configured to direct the third bright field beam to the fourth area of the objective lens; wherein The fourth area of the objective lens may be configured to direct the third bright field light beam to the object.

The illumination module may also be configured to illuminate the fifth area of the beam splitter with a fourth bright field beam; wherein the fifth area of the beam splitter may be configured to direct the fourth bright field beam to the fifth area of the objective lens; wherein The fifth area of the objective lens may be configured to direct the fourth bright field light beam to the object.

The system can include a second additional lens that can be positioned between the camera and the beam splitter.

The lighting module may include a blocking element that may be positioned at the focal plane of the bright field light source of the lighting module.

The lighting module may include a dark field light source and a reflector; and wherein the reflector may be configured to receive the dark field light beam from the dark field light source and guide the dark field light beam to the object.

The mirror can be positioned between the objective lens and the object.

The optical axis of the dark field illumination module can be oriented to the optical axis of the illumination module.

The lighting module can also be configured to (a) control the phase and polarization of the second dark field light beam, and (b) illuminate the object with the second dark field light beam.

The method may include setting the polarization characteristics of a plurality of collection paths of the inspection system by the controller, wherein each collection path may include a camera and an analyzer that defines the polarization characteristics of the collection path; and the illumination module (a) converts the bright field beam to The first angle range is directed to the object, (b) the first dark field beam is directed to the object in the second angle range, and (c) the second dark field beam is directed to the object in the third angle range; At least one specular reflection of at least one of the first dark field light beam and the second dark field light beam is guided to the sensing module; and the detection signal is generated by the cameras of the multiple collection paths of the sensing module.

The method may include (a) directing the specular reflection of the bright field beam to the sensing module when the area of the object may include a zone with a first orientation; (b) when the area of the object may include a zone with a second orientation The specular reflection of the first dark field light beam is guided to the sensing module; and (c) when the area of the object may include a zone with a third orientation, the specular reflection of the second dark field light beam is directed to the sensing module; The orientation, the second orientation, and the third orientation are different from each other.

The method may include setting the polarization characteristics of the plurality of collection paths such that during a given point in time, the polarization characteristics of the first collection path are different from the polarization characteristics of the second collection path.

The lighting module may or may not include any polarizers.

The lighting module may include at least one polarizer, which may be associated with at least one of the bright field light beam, the first dark field light beam, and the second dark field light beam.

The lighting module may include a bright-field light source, which may be followed by a blocking element; wherein the method may include preventing the bright-field beam from being irradiated on the third area of the beam splitter.

The method may include illuminating the second region of the beam splitter with the second bright field beam by the illumination module; directing the second bright field beam to the second region of the objective lens by the second region of the beam splitter; The second bright field light beam is directed to the object so as to irradiate the object with a third angle range different from the first angle range and the second angle range.

The method may include illuminating the fourth region of the beam splitter with the third bright field beam by the illumination module; directing the third bright field beam to the fourth region of the objective lens by the fourth region of the beam splitter; The area directs the third brightfield beam to the object.

The method may include illuminating the fifth region of the beam splitter with the fourth bright field beam by the illumination module; directing the fourth bright field beam to the fifth region of the objective lens by the fifth region of the beam splitter; The area directs the fourth brightfield beam to the object.

The camera may be behind the second additional lens.

The lighting module may include a blocking element that may be positioned at the focal plane of the bright field light source of the lighting module.

The lighting module may include a dark field light source and a reflector; and wherein the method may include receiving the dark field light beam by the reflector and from the dark field light source and directing the dark field light beam to the object.

The mirror can be positioned between the objective lens and the object.

The optical axis of the dark field illumination module can be oriented to the optical axis of the illumination module.

The method may include controlling the phase and polarization of the second dark field light beam by the illumination module, and illuminating the object with the second dark field light beam.

Detailed description of the preferred embodiment

Because the device for implementing the present invention is largely composed of electronic components and circuits known to those skilled in the art, for the understanding and recognition of the following concepts of the present invention and in order not to obscure or divide the teaching of the present invention Mind, the details of the circuit will not be explained to any degree that is deemed necessary as described above.

In the following specification, the present invention will be described with reference to specific examples of embodiments of the present invention. However, it is obvious that various modifications and changes can be made therein without departing from the broader spirit and scope of the present invention as set forth in the scope of the appended application.

A system that can utilize both dark field illumination and bright field illumination to provide wide-angle coverage is provided. Therefore, a system with the ability to inspect most of the specular reflections from uneven objects (eg, patterned PCB layers) is provided.

A system is provided that can utilize a large objective lens and a tilted aperture brightfield light entering the beam splitter so that one side of the objective lens projects light at an angle, while the opposite side of the mirror collects reflections. Thereby, a system with the ability to use the ellipsometry method is provided, which has the requirement for inspecting the entire article including its angled part and the leveled flat part.

According to an embodiment of the present invention, a system having two collection paths including two independent cameras and two independent polarization elements is provided. The polarization characteristics of each collection path can be set independently of the polarization characteristics of other inspection paths. These polarization characteristics can be set to be different from each other.

According to an embodiment of the present invention, there is provided a system having one or more analyzers having regions with different polarization parameters from each other.

Figures 1-6 show a system according to an embodiment of the present invention and an object being inspected with an uneven surface.

Figure 1 shows a system 81 for inspecting an object (also referred to as an object or an object to be inspected) 2. The system includes: a. Table 1, which is used to support and/or move objects 2. b. Two dark field (DF) light sources 7, which are configured to illuminate the object with two DF beams (one from each side of the object). c. Beam splitter 5. d. Bright field (BF) light source 6, which directs the BF beam onto the beam splitter 5. e. The objective lens 3, which is positioned between the beam splitter 5 and the second beam splitter 14. f. The first camera 15. g. The first analyzer 171, which is positioned between the second beam splitter 14 and the first camera 15. h. The second camera 16. i. The second analyzer 172, which is positioned between the second beam splitter 14 and the second camera 16. j. Image processor 141. k. Controller 142.

The controller 142 is configured to control the operation of the system. The controller 142 and the camera 4 are coupled to the image processor 141. The controller 142 may also be coupled to various elements (and control their operations) such as the BF light source 6, the dark field light source 7, the analyzers 171 and 172, etc.

The image processor 141 is configured to process detection signals generated by the first and second cameras 15 and 16.

The two DF light sources 7 (the right dark field light source and the left dark field light source) can be positioned relative to the optical axis 11 in a symmetrical manner. It should be noted that there may be only a single DF light source, the DF light source may be positioned in an asymmetric manner, that is, there may be more than two dark field light sources, and so on.

The beam splitter 5 is positioned above the inspected article 2 and is arranged to guide the BF light beam from the BF light source 6 to the inspected article 2 and to guide the light from the inspected article 2 to the objective lens 3.

The light guided to the objective lens 3 may include at least one of specular reflection and/or diffuse reflection of at least one of the BF beam and any beam from the DF source 7. The light directed to the objective lens 3 may depend on the orientation of the area illuminated by the light beam. Different orientations may result in (a) only diffuse reflection toward the direction of the objective lens 3 or (b) specular reflection of one of the BF beams and DF beams toward the direction of the objective lens 3.

The light passing through the objective lens 3 propagates toward the second beam splitter 14, and the second beam splitter 14 directs the light toward the first and second analyzers 171 and 172 and the first camera following the analyzers 171 and 172 And the second cameras 15 and 16 for beam splitting.

The dashed frame in each of the cameras 15 and 16 may represent the sensing element of each camera.

Figure 1 also shows the optical axis 19 of the BF beam.

The analyzers 171 and 172 may have adjustable polarization (such as orientation) such that the orientations of 171 and 172 are different from each other at a certain point in time and may be equal to each other at other points in time.

Figure 1 shows that the two collection paths have a shared part (between the object under inspection 2 and the second beam splitter 14) and an unshared part (after the second beam splitter 14). In FIG. 1, although other separation elements can be used (for example, 3CCD camera-separated to RGB), the separation of the collection path is achieved by the second beam splitter 14.

In Fig. 1, there are no polarization elements in the illumination path (between the BF light source 6 and the beam splitter 5 or between the DF light source 7 and the object or between the beam splitter 5 and the object 2). This is only an option and there may be one or more polarizers in the illumination path.

Many analysis methods can use the polarization properties of materials and specular reflections (by using polarizers and/or phase compensators in the illumination path or the collection path (before the camera and included in the camera) or in both the illumination path and the collection path. Such as quarter-wave retarder)).

Therefore, the system can use adjustable (or non-adjustable) polarization elements such as an adjustable polarizer 9 and/or an adjustable phase compensator and allow them to be rotated.

The analyzer (polarizer on the camera side) function can also be incorporated into the camera sensor, liquid crystal variable polarizer, or other implementations of them.

Each camera may be a line camera such as CCD or CMOS and the illumination may include one line-illuminated bright field light source and two line-dark field light sources.

An area scanning camera with an area illumination system may be provided and may include one or more bright field light sources and a dark field illumination ring surrounding the objective lens. Other arrangements of dark field light sources can be provided.

As described above, the camera-side polarizer (analyzer) can optionally be implemented as part of the camera primitive sensor or in the liquid crystal. Similarly, the illumination side of the polarizing element is optional and can be implemented in various ways.

Fig. 2 shows a system 82 and an object to be inspected having an uneven surface according to an embodiment of the present invention.

The following reference digits are used in Figure 2: a. 1-Table (used to support the object to be inspected). b. 2- The object to be inspected. c. 3-Objective lens. d. 5- Beam splitter. e. 6-Bright field light source. f. 7-Dark field light source. g. 9-Adjustable polarizer. h. 10- Adjustable phase compensator. i. 11-Focusing lens. j. 14-Second beam splitter. k. 15-The first camera. l. 16-Second camera. m. 31, 30 and 32 of the objective lens-left (first) area, central (third) area and right (second) area. n. 51, 50 and 52 of the beam splitter-left (first) area, central (third) area and right (second) area. p. 101-Brightfield beam. q. 102- Specular reflection of bright field beams. r. 111 and 112-dark field beams. s. 114-Diffuse reflection of dark field beams. t. 141-Image processor. u. 142-Controller. v. 171-The first analyzer. w. 172-Second analyzer.

The controller 142 is configured to control the operation of the system. The controller 142, the first camera 15 and the second camera 16 are coupled to the image processor 141. The controller 142 is also coupled to various elements such as the bright field light source 6, the dark field light source 7, the adjustable polarizer 9 and the adjustable phase compensator 10, the first and second analyzers 171 and 172 (and Control their operations).

In FIG. 2, the bright field light source 6 illuminates the left area 51 of the first beam splitter 5 with the first bright field light beam 102. The left area 51 of the first beam splitter 5 reflects the first bright field light beam 101 to the left area 31 of the objective lens 3, which focuses the first bright field light beam 101 and directs the first bright field light beam 101 to the object 2 at an angle. Left to the imaginary y-axis that extends along the optical axis of the camera. The specular reflection 102 of the first brightfield light beam 101 is reflected from the object 2 to the right area 32 of the objective lens 3. The specular reflection 102 may occur from the area of the object being inspected that is oriented in a substantially horizontal manner. The specular reflection 102 passes through the right area 52 of the first beam splitter 5 and is focused by the focusing lens 11. The second beam splitter 14 splits the light toward the first and second analyzers 171 and 172 followed by the first and second cameras 15 and 16.

The detection signals from the first and second cameras 15 and 16 are supplied to the image processor 141.

In FIG. 2, the first dark field beam and the second dark field beams 111 and 112 irradiate the level part of the object 2 and their specular reflections (not shown) are not collected by the objective lens 3.

FIG. 2 shows that the diffuse reflection 114 of the first dark field light beam and/or the second dark field light beam 111 and 112 can be guided to the third area (central area) 30 of the objective lens 3. The diffuse reflection 114 passes through the third area 50 of the first beam splitter 5 and is focused by a focusing lens 11 (not shown), which is followed by a second beam splitter 14 that splits the light.

Figure 3 shows a system 82 according to an embodiment of the invention.

In Fig. 3, the first bright field light beam 101 and the first dark field light beam and the second dark field light beams 111 and 112 irradiate the non-level area of the object 2'with a positive slope.

The specular reflection (not shown) of the first bright field light beam 101 and the specular reflection (not shown) of the second dark field light beam 112 are not collected by the objective lens 3.

The specular reflection 115 of the first dark field light beam 111 propagates toward the third region (central region) 30 of the objective lens 3. The specular reflection 115 passes through the third area 50 of the beam splitter 5 and is focused by the focusing lens 11. The focused light is split by the second beam splitter 14 and directed through the first and second analyzers 171 and 172 to the first and second cameras 15 and 16 respectively.

The detection signals from the first and second cameras 15 and 16 are supplied to the image processor 141.

FIG. 3 shows that the diffuse reflection 104 of the first brightfield light beam 101 can be directed to the right (second) region 32 of the objective lens 3. The diffuse reflection 104 passes through the second area 52 of the beam splitter 5 and is focused on the camera 4 by a focusing lens (not shown).

It should be noted that in any figure, only some of the diffuse reflections may be shown.

Figure 4 shows a system according to an embodiment of the invention.

In FIG. 4, there are two preferred collimated brightfield beams 101 and 121 to replace the single brightfield light in FIG. 1, and there are specular reflection 102 of the first brightfield beam 101 and specular reflection of the second brightfield beam 121 122.

In FIG. 4, the bright field light source 6, the adjustable polarizer 9 and the adjustable phase compensator 10 are followed by the blocking element 11, which is configured to prevent the bright field beam from irradiating the third area of the beam splitter 5. 50 and split a single brightfield beam into two brightfield beams.

The bright field illumination module of FIG. 4 includes a blocking element 11 and is configured to illuminate the second area 52 of the first beam splitter 5 with a second bright field beam 121.

The second area 52 of the first beam splitter 5 is configured to guide the second bright field beam 121 to the second area 32 of the objective lens 3.

The second area 32 of the objective lens 3 is configured to direct the second bright field light beam 121 to the object 2 so as to irradiate the object with a third angle range different from the first angle range and the second angle range.

The first area 51 of the first beam splitter is configured to direct the first brightfield beam 101 to the first area 31 of the objective lens.

The first area 31 of the objective lens is configured to direct the first bright field light beam 101 to the object 2 so as to irradiate the object in a first angular range.

In some cases (when illuminating the area of the first orientation-as shown in FIG. 4)-(a) the second area 32 of the objective lens is configured to receive the specular reflection 102 of the first brightfield beam and The specular reflection 102 of the bright field beam is directed to the second region 52 of the beam splitter; (b) the second region 52 of the first beam splitter is configured to direct the specular reflection 102 of the first bright field beam to the second beam splitter 14 (C) the third area 30 of the objective lens is configured to guide the diffuse reflection 114 of the dark field beams 111 and 112 to the third area 30 of the objective lens; and (d) the third area 30 of the first beam splitter is configured to The diffuse reflection 114 of the dark field beam is directed to the second beam splitter 14.

It should be noted that the camera 15 and the camera 16 may receive one or more regions according to the orientation of the regions illuminated by the first bright field beam 101, the first dark field beam 111, and the second dark field beam 112 at a given time. Diffuse reflection and/or specular reflection of light beams 101, 111, and 112 (or none).

When the area of the object is illuminated, the different areas of the differently oriented area of the object can specularly reflect the light from different light sources. The zone of the area may include one or more points of the area. Non-limiting examples of illuminated areas of different orientations are provided in Figures 2 and 3. Figures 2 and 3 may show different cross-sections of wires that are illuminated at the same time or at different times.

In Figure 2, the illuminated area is shown as including a level zone and the specular reflection is the specular reflection of the bright field beam. In Figure 3, the illuminated area is shown as including an oblique area and the specular reflection is the specular reflection of the first dark field beam. It should be noted that the illuminated area may include a first oriented area and a second oriented area, so that the specular reflection of the bright field beam and the specular reflection of the dark field beam can be collected.

Figures 5 and 6 show options for a telecentric setting with coaxial illumination. The coaxial illumination may include an illumination barrier that covers the central ray of the illumination and realizes a "donut" projection of light on the object under inspection.

Figures 5 and 6 show two parts of a system according to an embodiment of the invention. Figure 6 is taken along the first virtual plane and Figure 5 is taken along the second virtual plane-the second virtual plane is oriented (eg-orthogonal) to the first virtual plane. For example-the first virtual plane can be a Z-Y plane and the second virtual plane can be a Z-X plane.

In FIG. 5, the bright field illumination module includes a bright field light source 6, an adjustable polarizer 9 and an adjustable phase compensator 10. The bright field illumination module is followed by a first additional objective lens 61, and the first additional objective lens 61 is followed by a beam splitter 5. In FIG. 3, the beam splitter 5 is positioned to the right of the first additional objective lens 61. The second additional objective lens 62 is positioned above the beam splitter 5 and below the camera 4. The objective lens 3 is positioned above the object 2 and below the beam splitter 5.

The first additional objective lens 61 and the second additional objective lens 62 are parallel to each other and are formed in a telecentric arrangement.

In FIG. 5, there are a first brightfield beam 201, a second brightfield beam 202, a third brightfield beam 203, a fourth brightfield beam 204, a specular reflection 211 of the first brightfield beam 201, and a second brightfield beam The specular reflection 212 of 202, the specular reflection 213 of the third bright field beam 203, the specular reflection 214 of the fourth bright field beam 204, the diffuse reflection 303 of the two dark field beams 301 and 302, and the two dark field beams 301 and 302.

In FIG. 5, the blocking element is positioned at the focal plane of the bright field light source 6. FIG. 5 shows two bright field beams, which are separated by the blocking element into a first bright field beam to a fourth bright field beam 201, 202, 203, 204.

The first to fourth bright field beams 201, 202, 203, 204 pass through the first additional objective lens 61 and irradiate the first area, second area, third area, and fourth area of the beam splitter. The first area, the second area, the third area, and the fourth area of the objective lens 3 are guided.

The objective lens 3 directs the first bright field beam and the second bright field beams 201 and 202 to the first position of the object.

The objective lens 3 directs the third bright field beam and the fourth bright field beams 203 and 204 to a second position of the object, which is separated from the first position.

In some cases (when illuminating the area of the first orientation-as shown in Figure 5)-(a) the specular reflection 211 of the first brightfield beam 201 and the specular reflection 212 of the second brightfield beam 202 It travels through the second area and the first area of the objective lens 3, passes through the second area and the first area of the beam splitter, and is guided to the fourth area of the camera by the second additional objective lens 62; (b) the third light The specular reflection 213 of the field beam 203 and the specular reflection 214 of the fourth bright field beam 204 pass through the fourth area and the third area of the objective lens 3, pass through the fourth area and the third area of the beam splitter, and are propagated by the second additional The objective lens 62 is guided to the first area of the camera.

There can be more than two pairs of brightfield beams.

FIG. 6 shows that the dark field light beams 301 and 302 are generated by the dark field light source 6, pass through the adjustable polarizer 9 and the adjustable phase compensator 10 and are reflected by the mirrors 71 and 72 to illuminate the object 2.

The diffuse reflection 303 passes through the objective lens 3 and the second additional objective lens to illuminate the second beam splitter 14, which directs the diffuse reflection 303 to the first and second analyzers 171 and 172 and to the first camera And the second cameras 15 and 16 are on.

Figure 7 shows two analyzers according to various embodiments of the invention.

These analyzers can be used in systems such as the systems of FIGS. 1-7, but can be used in systems such as those shown in FIG. 4 having a single camera 15, a single analyzer 171, and excluding the second beam splitter 14. In the system.

The system of FIG. 4 has a single camera but has a polarizer with different zones whose polarization characteristics are different from each other (for example-the polarization orientations may be different from each other).

Different regions of the same analyzer may have the same shape and size, but may differ from each other in shape and/or size.

FIG. 7 shows an analyzer 250 having elongated strips 251, 252, 253, and 254 whose polarization parameters are different from each other. The analyzer can be adapted to line illumination, where the object under inspection is scanned by a beam of light, and therefore (assuming there are 4 different areas of the analyzer)-a single scan results in the capture of four different images of the object under inspection- Each has its own polarization parameter.

Figure 7 also shows an analyzer 260 with four different types (261, 262, 263, and 264) of rectangular regions, which are arranged in a repeating (mosaic) pattern, which can resemble the Bayer pattern of an RGB primitive array. This arrangement can be adapted to area lighting.

In FIG. 7, frames including wires of different orientations are different from each other in their polarization parameters. For example, boxes 251 and 261 may represent linear polarization oriented at 45 degrees, boxes 252 and 262 may represent linear polarization oriented at 90 degrees, boxes 253 and 263 may represent linear polarization oriented at 0 degrees, and boxes 254 and 264 may represent no polarization. It should be noted that the polarization orientation may be different from this example and different lines may indicate the difference between other polarization parameters.

The number of different zone types can be different from four.

It is possible to provide a method for inspecting the item being inspected using any of the systems shown above.

Figure 8 shows a method 400 according to an embodiment of the invention.

The method 400 starts with a preparation step 410 of a controller setting the polarization characteristics of a plurality of collection paths of the inspection system, wherein each collection path includes a camera and an analyzer that defines the polarization characteristics of the collection path.

The polarization characteristics of one or more collection paths may be different from those of another collection path during at least one point in time.

Step 410 may be repeated (and the settings may be changed) in each or more of steps 420, 430, 440, 450, and 460.

Step 410 can be followed by step 420. In step 420, the illumination module (a) directs the bright field beam to the object in a first angular range, (b) directs the first dark field beam to the object in a second angular range, and (c ) Direct the second dark field beam to the object in the third angular range.

Step 420 can be followed by step 430, which guides at least one specular reflection of at least one of the bright field light beam, the first dark field light beam, and the second dark field light beam to the sensing module.

Step 430 can be followed by step 440. In step 440, detection signals are generated by the cameras of the multiple collection paths of the sensing module.

Step 430 may include when the area of the object includes a region having a first orientation (for example, between -10 degrees and +10 degrees), directing the specular reflection of the bright field beam to the sensing module; (b) when the object The area of includes the area with the second orientation (for example, between 35 degrees and 55 degrees) when the specular reflection of the first dark field beam is directed to the sensing module; and (c) when the area of the object includes the area with the third orientation (For example, between -35 degrees and -55 degrees), the specular reflection of the second dark field beam is directed to the sensing module; wherein the first orientation, the second orientation, and the third orientation are different from each other.

Step 440 can be followed by step 420. Step 420 can be followed by step 410 (when the setting of the collection path needs to be changed).

Step 440 can be followed by step 450, which stores the detection signal and/or transmits the detection signal and/or generates an image based on the detection signal and/or processes the image to provide a result, and so on.

The method may further include repeating at least some of steps 410, 420, 430, 440, and 450 while scanning the object. This can include introducing relative movement between the lighting module and the object. For each scan or multiple scans, step 410 may be performed one or more times.

Furthermore, those skilled in the art will recognize that the boundaries between the functions of the operations described above are merely illustrative. The functions of multiple operations may be combined into a single operation, and/or the functions of a single operation may be dispersed in additional operations. In addition, alternative embodiments may include multiple instances of specific operations, and the order of operations may be changed in various other embodiments.

Therefore, it will be understood that the architecture described herein is only exemplary, and in fact many other architectures that achieve the same function can be implemented. Abstractly, but still has a clear meaning, any arrangement of components to obtain the same function is effectively "associated" so that the desired function is obtained. Therefore, any two components herein that are combined to obtain a specific function can be regarded as "associated" with each other, so that the desired function is obtained regardless of the architecture or intermediate components. Likewise, any two components so associated may also be regarded as being "operably connected" or "operably coupled" to each other to obtain the desired function.

However, other modifications, changes and alternatives are also possible. Therefore, the description and the drawings are regarded as illustrative rather than restrictive.

The word "comprising" does not exclude the presence of other elements or steps other than those listed in the scope of the patent application. It should be understood that the terms so used are interchangeable under appropriate circumstances such that the embodiments of the invention described herein are, for example, capable of operating in other orientations than those shown or otherwise described herein. Any reference to the terms "comprising" and "comprises" shall also be interpreted as referring to the term "composition" (excluding the presence of other elements) and/or referring to the term "essentially consisting" (excluding other materials or The existence of important components) references.

In addition, the term "a" or "an" as used herein is defined as one or more than one. In addition, the use of introductory phrases such as "at least one" and "one or more" in the scope of the patent application should not be construed as implying another claim introduced by the indefinite article "a" or "an" The element will include any particular patented scope of the claimed element so introduced to the invention that includes only one such element (even when the same patentable scope includes the introductory phrase "one or more" or "at least one "And indefinite articles such as "a" or "an"). The same applies to the use of definite articles. Unless otherwise stated, terms such as "first" and "second" are used to arbitrarily distinguish between elements described by such terms.

Therefore, these terms are not necessarily intended to indicate the chronological order or other priorities of such elements. The mere fact that certain measures are specified in mutually different patent applications does not indicate that the combination of these measures cannot be used to advantage.

1: table 2, 2’: Object 3: Objective lens 4: camera 5: beam splitter 6: Bright field (BF) light source 7: Dark field (DF) light source 9: Adjustable polarizer 10: Adjustable phase compensator 11: Optical axis; focusing lens; blocking element 14: Second beam splitter 15: The first camera 16: second camera 19: Optical axis of BF beam 30: The central (third) area of the objective lens 31: The left (first) area of the objective lens 32: The right (second) area of the objective lens 50: The central (third) area of the beam splitter 51: Left (first) area of the beam splitter 52: The right (second) area of the beam splitter 61: The first additional objective 62: The second additional objective lens 71, 72: mirror 81, 82: System 101, 201: first brightfield beam 102: The second brightfield beam; the specular reflection of the first brightfield beam 104: diffuse reflection 111: first dark field beam 112: second dark field beam 114: Diffuse reflection of dark field beams 115: Specular reflection of the first dark field beam 121, 202: second brightfield beam 122, 212: Specular reflection of the second brightfield beam 141: image processor 142: Controller 171: The first analyzer 172: second analyzer 203: third brightfield beam 204: The fourth brightfield beam 211: Specular reflection of the first brightfield beam 213: Specular reflection of the third brightfield beam 214: Specular reflection of the fourth brightfield beam 250, 260: Analyzer 251, 252, 253, 254: strips; frame 261, 262, 263, 264: frame 301, 302: dark field beam 303: Diffuse reflection of dark field beams 400: method 410, 420, 430, 440, 450, 460: steps

From the following detailed description in conjunction with the accompanying drawings, the present invention will be more fully understood and understood. In the accompanying drawings: Figure 1 shows an inspection system according to an embodiment of the present invention; Figure 2 shows an inspection system according to an embodiment of the present invention; Figure 3 shows an inspection system according to an embodiment of the present invention; Figure 4 shows an inspection system according to an embodiment of the present invention; Figure 5 shows an inspection system according to an embodiment of the present invention; Figure 6 shows an inspection system according to an embodiment of the present invention; Figure 7 shows an analyzer according to an embodiment of the present invention; and Figure 8 shows a method according to an embodiment of the invention.

1: table

2: Object

3: Objective lens

5: beam splitter

6: Bright field (BF) light source

7: Dark field (DF) light source

14: Second beam splitter

15: The first camera

16: second camera

19: Optical axis of BF beam

81: System

141: image processor

142: Controller

171: The first analyzer

172: second analyzer

Claims (28)

A system for inspecting objects based on polarization characteristics, the system comprising: A sensing module, which includes a plurality of collection paths, each collection path includes a camera and an analyzer that defines the polarization characteristics of the collection path; A controller configured to set the polarization characteristics of the plurality of collection paths independently of each other; Beam splitter Objective lens An illumination module, which is configured to (a) direct a bright field light beam to the area of the object in a first angle range; (b) direct the first dark field light beam to the area of the object in a second angle range; (c) Direct the second dark field light beam to the area of the object in a third angular range; (d) Direct the light from the bright field light beam, the first dark field light beam, and the second dark field light beam At least one specular reflection of at least one light beam of at least one guides the sensing module; The lighting module is configured as: a. When the region of the object includes a region with a first orientation, direct the specular reflection of the bright field beam to the sensing module; b. When the area of the object includes a region with a second orientation, directing the specular reflection of the first dark field beam to the sensing module; and c. When the area of the object includes a zone with a third orientation, the specular reflection of the second dark field beam is directed to the sensing module; wherein, the first orientation, the first orientation The second orientation and the third orientation are different from each other. The system for inspecting objects based on polarization characteristics according to claim 1, wherein the controller is configured to set the polarization characteristics of the plurality of collection paths so that during a given point in time, the first collection The polarization characteristics of the path are different from the polarization characteristics of the second collection path. The system for inspecting an object based on polarization characteristics according to claim 1, wherein the illumination module does not include any polarizer. The system for inspecting objects based on polarization characteristics according to claim 1, wherein the illumination module includes at least one polarizer, and the at least one polarizer is connected to the bright field light beam and the first dark field. The light beam is associated with at least one light beam in the second dark field light beam. The system for inspecting objects based on polarization characteristics according to claim 1, wherein the illumination module includes a bright field light source, followed by the bright field light source is a blocking element, and the blocking element is configured to block the The bright field beam irradiates the third area of the beam splitter. The system for inspecting an object based on polarization characteristics according to claim 1, wherein the illumination module is further configured to illuminate the second area of the beam splitter with a second bright field light beam; Wherein, the second area of the beam splitter is configured to guide the second bright field light beam to the second area of the objective lens; Wherein, the second area of the objective lens is configured to direct the second bright field light beam to the object so as to irradiate the object with a third angle range that is different from the first angle range and the second angle range. Object. The system for inspecting objects based on polarization characteristics according to claim 6, wherein the illumination module is further configured to illuminate the fourth area of the beam splitter with a third bright field light beam; Wherein, the fourth area of the beam splitter is configured to guide the third bright field light beam to the fourth area of the objective lens; Wherein, the fourth area of the objective lens is configured to guide the third bright field light beam to the object. The system for inspecting an object based on polarization characteristics according to claim 7, wherein the illumination module is further configured to illuminate the fifth area of the beam splitter with a fourth bright field light beam; Wherein, the fifth area of the beam splitter is configured to guide the fourth bright field light beam to the fifth area of the objective lens; Wherein, the fifth area of the objective lens is configured to guide the fourth bright field light beam to the object. The system for inspecting an object based on polarization characteristics according to claim 8, wherein the system includes a second additional lens positioned between the camera and the beam splitter. The system for inspecting an object based on polarization characteristics according to claim 1, wherein the illumination module includes a blocking element positioned at a focal plane of a bright field light source of the illumination module. The system for inspecting objects based on polarization characteristics according to claim 1, wherein the illumination module includes a dark field light source and a reflector; and wherein the reflector is configured to receive from the dark field light source The dark field light beam and the dark field light beam are directed to the object. The system for inspecting an object based on polarization characteristics according to claim 11, wherein the mirror is positioned between the objective lens and the object. The system for inspecting an object based on polarization characteristics according to claim 1, wherein the optical axis of the dark field illumination module is oriented to the optical axis of the illumination module. The system for inspecting an object based on polarization characteristics according to claim 1, wherein the illumination module is further configured to (a) control the phase and polarization of the second dark field beam, and (b) use the The second dark field beam illuminates the object. A method for inspecting objects based on polarization characteristics, including: Setting the polarization characteristics of a plurality of collection paths of an inspection system by a controller, wherein each collection path includes a camera and an analyzer that defines the polarization characteristics of the collection path; With an illumination module, (a) direct a bright field beam to an object in a first angle range; (b) direct a first dark field beam to the object in a second angle range; (c) direct a second dark field The light beam is directed to the object in the third angular range; Guiding at least one specular reflection of at least one of the bright field light beam, the first dark field light beam and the second dark field light beam to a sensing module; Generating sensing signals by cameras of multiple collection paths of the sensing module; Containing (a) when the area of the object includes a zone with a first orientation, directing the specular reflection of the bright field beam to the sensing module; (b) when the area of the object When it includes a region with a second orientation, direct the specular reflection of the first dark field beam to the sensing module; and (c) when the region of the object includes a region with a third orientation, The specular reflection of the second dark field beam is guided to the sensing module; wherein the first orientation, the second orientation, and the third orientation are different from each other. The method for inspecting an object based on polarization characteristics according to claim 15, including setting the polarization characteristics of the plurality of collection paths so that during a given point in time, the polarization characteristics of the first collection path are the same as the first collection path. The polarization characteristics of the second collection path are different. The method for inspecting an object based on polarization characteristics according to claim 15, wherein the illumination module does not include any polarizer. The method for inspecting an object based on polarization characteristics according to claim 15, wherein the illumination module includes at least one polarizer, and the at least one polarizer is related to the bright field light beam and the first dark field. The light beam is associated with at least one light beam in the second dark field light beam. The method for inspecting an object based on polarization characteristics according to claim 15, wherein the illumination module includes a bright field light source, and the bright field light source is followed by a blocking element; wherein the method includes blocking the bright field light beam Irradiate on the third area of the beam splitter. The method for inspecting an object based on polarization characteristics according to claim 15, comprising illuminating a second area of the beam splitter by the illumination module with a second bright field beam; The second area of the device directs the second bright field beam to the second area of the objective lens; and the second area of the objective lens directs the second bright field beam to the object so as to be different from the The first angle range and the third angle range of the second angle range are irradiated on the object. The method for inspecting an object based on polarization characteristics according to claim 20, comprising illuminating a fourth area of the beam splitter by the illumination module with a third bright field beam; The fourth area of the device directs the third bright field light beam to the fourth area of the objective lens; and the fourth area of the objective lens directs the third bright field light beam to the object. The method for inspecting an object based on polarization characteristics according to claim 21, comprising illuminating the fifth area of the beam splitter by the illumination module with a fourth bright field beam; The fifth area of the device directs the fourth bright field light beam to the fifth area of the objective lens; the fifth area of the objective lens directs the fourth bright field light beam to the object. The method for inspecting an object based on polarization characteristics according to claim 22, wherein the camera has a second additional lens before it. The method for inspecting an object based on polarization characteristics according to claim 15, wherein the illumination module includes a blocking element positioned at a focal plane of a bright field light source of the illumination module. The method for inspecting an object based on polarization characteristics according to claim 15, wherein the illumination module includes a dark field light source and a reflector; and wherein the method includes using the reflector and from the dark The field light source receives the dark field light beam and directs the dark field light beam to the object. The method for inspecting an object based on polarization characteristics according to claim 25, wherein the mirror is positioned between the objective lens and the object. The method for inspecting an object based on polarization characteristics according to claim 15, wherein the optical axis of the dark field illumination module is oriented to the optical axis of the illumination module. The method for inspecting an object based on polarization characteristics according to claim 15, including controlling the phase and polarization of a second dark field light beam by the illumination module, and illuminating the second dark field light beam object.

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