DE102015101693B4 - Optical inspection system - Google Patents

Abstract

Optical inspection system (1) for inspecting a measurement object (2) with:
- a first optical module (10) comprising:
a first light source (100) which has a first optical axis (A1) and which emits light towards the measurement object (2), a first image acquisition unit (102) simultaneously acquiring an image of the measurement object (2), the first image acquisition unit (102 ) has a first image acquisition axis (B1) and the first optical axis (A1) and the first image acquisition axis (B1) are symmetrical with respect to a normal line (N) of an inspection plane (P) on the measurement object (2) and a first angle (Φ ) is formed between the first optical axis (A1) and the image capture axis (B); and
- a second optical module (12) comprising:
a second light source (120) which has a second optical axis (A2) and emits light towards the measurement object (2), a second image capturing unit (122) simultaneously capturing an image of the measurement object (2), the second image capturing unit (122) has a second image acquisition axis (B2) and the second optical axis (A2) and the second image acquisition axis (B2) are symmetrical with respect to the normal line (N) and a second angle (Θ) which differs from the first angle (Φ), is formed between the second optical axis (A2) and the second image capturing axis (B2).

Description

BACKGROUND

Technical area

The present disclosure relates to an optical inspection system, and more precisely to a three-dimensional measuring system.

Description of the prior art

In general, methods of measuring the three-dimensional shape of a DUT (measurement object) can be divided into contact method and non-contact method. Contactless methods typically include the projection of a laser point, a laser beam or a structured light (e.g. light stripes) onto a DUT and the subsequent scanning, which is carried out point by point, line by line or stripe by stripe. Based on the triangular constellation of the light source, the DUT and the imaging position, the height values of the three-dimensional shape of the DUT can be calculated.

7th Fig. 3 is a schematic diagram showing a conventional optical inspection system 7th illustrated. As in 7th has the optical inspection system 7th two light sources 70 as well as a camera 72 . The light sources 70 are located on two sides of a DUT 2 and emit light to the DUT 2 down. The camera 72 is located just above the DUT 2 to receive light coming from the DUT 2 is reflected to thereby produce corresponding images of the DUT 2 to generate.

However, the conventional optical inspection system can 7th cannot be applied to certain DUTs, such as objects with mirror surfaces. With such objects with mirror surfaces, a large amount of the emitted light cannot reach the camera 72 because this light is reflected from the objects according to the law of reflection. Hence the intensity of the reflected light coming from the camera 72 is received too low, so that the image contrast is poor, as a result of which the subsequent algorithmic interpretations are impaired. Even if the optical inspection system 7th can be modified in such a way that it conforms to the law of reflection and thereby a better image contrast is achieved, problems with shadowing and image distortion will arise in the captured images. The problem of image distortion can be compensated for using an algorithm, but the problem of shadowing cannot be solved.

Accordingly, the industry seeks to provide an optical inspection system by which the aforementioned problems can be solved.

The US 2014/0168417 A1 discloses an inspection system that includes a source module, an image capture module, and a processor unit. The source module emits two light beams one after the other, which fall on a DUT and are then recorded by the image acquisition module. The light beams can have different configurations, for example they can differ in their polarization, their wavelength or their angle of incidence. The document further discloses an arrangement in which two source modules and two image capture modules are used. A source module and an associated image acquisition module are arranged asymmetrically in relation to the normal to the object plane. In addition, both source modules or both image acquisition modules are each on the same side of the normal. Furthermore, a DUT is described which has two regions that can differ in their optical properties. The processor unit calculates a contrast ratio in order to obtain a high-contrast image with its help.

The DE 10 2005 031 957 A1 comprises an inspection system which comprises two light sources, a camera system and a control unit. The light sources are arranged at a distance from one another so that the emitted light beams have a different angle of incidence on the DUT, but can be detected by the camera at the same time. The control device can control the two light sources independently of one another, in particular with regard to different switch-on times and durations.

The DE 10 2004 034 160 A1 discloses an inspection system which consists of a plurality of radiation devices and a plurality of detectors which are arranged at fixed solid angles to one another. A spatially resolved detection of the radiation reflected back by the DUT can thus be obtained.

SUMMARY

The disclosure provides an optical inspection system for inspecting a DUT (DUT). The optical inspection system comprises a first optical module and a second optical module. The first optical module comprises a first light source and a first image acquisition unit. The first light source has a first optical axis. The first image capturing unit has a first image capturing axis. The first optical axis and the first image capture axis are symmetrical with respect to each other on a normal line of an inspection plane on the DUT. A first angle is formed between the first optical axis and the first image capture axis. The second optical module comprises a second light source and a second image capturing unit. The second light source has a second optical axis. The second image capturing unit has a second image capturing axis. The second optical axis and the second image capturing axis are symmetrical with respect to the normal line. A second angle is formed between the second optical axis and the second image capture axis, and the second angle is different from the first angle.

The first light source emits light towards the measurement object, while at the same time the first image acquisition unit receives an image of the measurement object. The second light source also emits light towards the measurement object, while at the same time the second image acquisition unit receives an image of the measurement object.

In one embodiment of the disclosure, the first light source and the second image capturing unit are located on one side of the normal line, and the second light source and the first image capturing unit are located on another side of the normal line.

In one embodiment of the disclosure, the first and second angles are in a range from 55 to 65 degrees.

In one embodiment of the disclosure, the first and the second light source emit unpolarized light or polarized light.

In one embodiment of the disclosure, the light emitted by the first light source generates a first edge pattern on the DUT. The first edge pattern has a first stripe spacing. Light emitted from the second light source generates a second edge pattern on the DUT. The second edge pattern has a second stripe spacing that is equal to the first stripe spacing.

In one embodiment of the disclosure, light emitted by the first light source generates a first edge pattern on the DUT. The first edge pattern has a first stripe spacing. Light emitted from the second light source generates a second edge pattern on the DUT, and the second edge pattern has a second stripe spacing that is different from the first stripe spacing.

The disclosure also provides an optical inspection system for inspecting a DUT. The optical inspection system comprises a first optical module and a second optical module. The first optical module comprises a first light source, a first image acquisition unit and a first filter. The first light source has a first optical axis. The first image capturing unit has a first image capturing axis. The first optical axis and the first image capturing axis are symmetrical with respect to a normal line of an inspection plane on the DUT. A first angle is formed between the first optical axis and the first image capture axis. The first filter is on the first image capture axis and has a first transmission spectrum. The second optical module comprises a second light source, a second image acquisition unit and a second filter. The second light source has a second optical axis. The second image capturing unit has a second image capturing axis. The second optical axis and the second image capturing axis are symmetrical with respect to the normal line. A second angle is formed between the second optical axis and the second image capture axis, and the second angle is different from the first angle. The second filter is located on the second image acquisition axis and has a second transmission spectrum which is shifted in relation to the first transmission spectrum. The first filter is set up to transmit most of the light which is emitted by the first light source and to reflect most of the light which is emitted by the second light source. The second filter is set up to reflect most of the light which is emitted by the first light source and to transmit most of the light which is emitted by the second light source.

In one embodiment of the disclosure, the light that is emitted by the first light source has a first triplet that matches the first transmission spectrum. The light emitted from the second light source has a second triplet that matches the second transmission spectrum.

In one embodiment of the disclosure, the first light source, the second filter and the second image capture unit are located on one side of the normal line. The second light source, the first filter and the first image capture unit are located on a different side of the normal line.

The disclosure also provides an optical inspection system for inspecting a DUT. The optical inspection system comprises a first optical module and a second optical module. The first optical module comprises a first image acquisition unit, a first filter and a first light source. The first image capturing unit has a first image capturing axis. The first filter is on the first image capture axis and has a first transmission spectrum. The first light source is used to emit light towards the first filter. The first filter is set up to reflect most of the light which is emitted by the first light source. The reflected light from the first light source has a first optical axis which coincides with the first image acquisition axis. The second optical module comprises a second image acquisition unit, a second filter and a second light source. The second image capturing unit has a second image capturing axis. The second image acquisition axis and the first image acquisition axis are symmetrical with respect to a normal line of an inspection plane on the DUT. The second filter is located on the second image acquisition axis and has a second transmission spectrum which is shifted in relation to the first transmission spectrum. The second light source is used to emit light towards the second filter. The second filter is set up to reflect most of the light that is emitted by the second light source. The reflected light from the second light source has a second optical axis that coincides with the second image capture axis. The first filter is also set up to transmit most of the light that is emitted by the second light source. The second filter is also set up to transmit most of the light that is emitted by the first light source.

In one embodiment of the disclosure, the light which is emitted by the first light source has a first triplet which corresponds to the second transmission spectrum. The light emitted from the second light source has a second triplet that matches the first transmission spectrum.

In one embodiment of the disclosure, the first optical module is on one side of the normal line and the second optical module is on another side of the normal line.

In one embodiment of the disclosure, a first angle is formed between the first image acquisition axis and the second image acquisition axis. The optical inspection system further comprises a third optical module and a fourth optical module. The third optical module comprises a third image acquisition unit, a third filter and a third light source. The third image capturing unit has a third image capturing axis. The third filter is located on the third image acquisition axis and has the first transmission spectrum. The third light source is used to emit light towards the third filter. The third filter is set up to reflect most of the light that is emitted by the third light source. The reflected light from the third light source has a third optical axis that coincides with the third image capture axis. The fourth optical module comprises a fourth image acquisition unit, a fourth filter and a fourth light source. The fourth image capturing unit has a fourth image capturing axis. The fourth image capture axis and the third image capture axis are symmetrical with respect to the normal line. A second angle is formed between the third image capture axis and the fourth image capture axis, and the second angle is different from the first angle. The fourth filter is located on the fourth image acquisition axis and has the second transmission spectrum. The fourth light source is used to emit light towards the fourth filter. The fourth filter is set up to reflect most of the light that is emitted by the fourth light source. The reflected light from the fourth light source has a fourth optical axis that coincides with the fourth image capture axis. The third filter is also set up to transmit most of the light that is emitted by the fourth light source. Furthermore, the fourth filter is set up to transmit most of the light which is emitted by the third light source.

In one embodiment of the disclosure, the light that is emitted by the third light source has a first triplet that matches the second transmission spectrum. The light emitted from the fourth light source has a second triplet that matches the first transmission spectrum.

In one embodiment of the disclosure, the third optical module is on one side of the normal line and the fourth optical module is on another side of the normal line.

In one embodiment of the disclosure, the third and fourth light sources emit unpolarized light or polarized light.

Thus, the inspection optical system of the disclosure arranges the optical axis of each of the light sources and the image capturing axis of the corresponding image capturing unit to be symmetrical with respect to the normal line of the inspection plane so that even in the event that the DUT has a mirror surface at the inspection plane , a large amount of the emitted light from each light source can be reflected to the corresponding image capture unit. The optical inspection system of the disclosure also positions the light sources on two opposite sides of the DUT with respect to the normal line, so that even if the images captured by the image capture units have shadows at different locations, the images are further analyzed and synthesized can to get a synthetic image without shadows, thereby solving the problem of shadowing can be. In addition, the optical inspection system of the disclosure is arranged so that the angle between the optical axis and the corresponding image capturing axis in one optical module is different from that in another optical module, so that the inspection ability of particles and short circuit problems are improved. Furthermore, the measurement range of the optical inspection system can be enlarged by adapting the above-mentioned angles. In addition, by using filters each of which allows only most of the light emitted from the corresponding light source to be transmitted, all of the image capturing units can capture images simultaneously, so that the inspection efficiency of the inspection optical system is improved.

It should be understood that both the foregoing general description and the following detailed description are exemplary in nature and are intended to provide further explanations of the disclosure as claimed.

Figure list

• 1 ist ein schematisches Diagramm, das ein optisches Inspektionssystem gemäß einer Ausführungsform der Offenlegung illustriert;
• 2 ist ein schematisches Diagramm, das das Messprinzip eines ersten Randmusters und eines zweiten Randmusters illustriert;
• 3 ist ein schematisches Diagramm, das ein optisches Inspektionssystem gemäß einer anderen Ausführungsform der Offenlegung illustriert;
• 4A ist ein Diagramm des relativen Transmissionsgrades gegenüber der Wellenlänge in Bezug auf einen ersten Filter aus 3;
• 4B ist ein Diagramm des relativen Transmissionsgrades gegenüber der Wellenlänge in Bezug auf einen zweiten Filter aus 3;
• 5A ist ein Diagramm der relativen Strahlungsleistung gegenüber der Wellenlänge in Bezug auf eine erste Lichtquelle aus 3;
• 5B ist ein Diagramm der relativen Strahlungsleistung gegenüber der Wellenlänge in Bezug auf eine zweite Lichtquelle aus 3;
• 6 ist ein schematisches Diagramm, das ein optisches Inspektionssystem gemäß einer anderen Ausführungsform der Offenlegung illustriert; und
• 7 ist ein schematisches Diagramm, das ein konventionelles optisches Inspektionssystem illustriert.

The disclosure can be better understood by reading the following detailed description of the embodiments, reference being made to the accompanying drawings as follows:

• 1 Figure 3 is a schematic diagram illustrating an optical inspection system according to an embodiment of the disclosure;
• 2 Fig. 13 is a schematic diagram illustrating the principle of measurement of a first edge pattern and a second edge pattern;
• 3 Figure 3 is a schematic diagram illustrating an optical inspection system according to another embodiment of the disclosure;
• 4A FIG. 14 is a graph of relative transmittance versus wavelength for a first filter from FIG 3 ;
• 4B Figure 12 is a graph of relative transmittance versus wavelength for a second filter from 3 ;
• 5A FIG. 14 is a diagram of the relative radiant power versus wavelength in relation to a first light source from FIG 3 ;
• 5B FIG. 12 is a diagram of the relative radiant power versus wavelength in relation to a second light source from FIG 3 ;
• 6th Figure 3 is a schematic diagram illustrating an optical inspection system according to another embodiment of the disclosure; and
• 7th Fig. 3 is a schematic diagram illustrating a conventional optical inspection system.

DETAILED DESCRIPTION

Reference will now be made in detail to the present embodiments of the disclosure, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used in the drawings and the description to refer to the same or like parts.

1 Fig. 3 is a schematic diagram showing an optical inspection system 1 illustrated in accordance with one embodiment of the disclosure. What 1 as far as is concerned, it will be the optical inspection system 1 for inspection of a DUT (DUT) 2 used. The optical inspection system 1 comprises a first optical module 10 and a second optical module 12th . The first optical module 10 includes a first light source 100 and a first image capture unit 102 . The first light source 100 has a first optical axis A1 attached to the DUT 2 is aligned. This means that the light exit surface of the first light source 100 the DUT 2 opposite. The first image capture unit 102 has a first image capture axis B1 attached to the DUT 2 is aligned. This means that the light receiving surface of the first image capture unit 102 the DUT 2 opposite. The first optical axis A1 and the first image capturing axis B1 are symmetrical with respect to a normal line N of an inspection plane P on the DUT 2 . A first angle Φ is formed between the first optical axis A1 and the first image capturing axis B1.

The second optical module 12th includes a second light source 120 and a second image capture unit 122 . The second light source 120 has a second optical axis A2 attached to the DUT 2 is aligned. This means that the light exit surface of the second light source 120 the DUT 2 opposite. The second image capture unit 122 has a second image capture axis B2 attached to the DUT 2 is aligned. This means that the light receiving surface of the second image capture unit 122 the DUT 2 opposite. The second optical axis A2 and the second image capturing axis B2 are symmetrical with respect to the normal line N. A second angle Θ is formed between the second optical axis A2 and the second image capturing axis B2, and the second angle Θ is different from the first angle Φ.

In the embodiment of the disclosure, even if the DUT 2 at the Inspection plane P has a mirror surface, a large amount of the emitted light of the first light source 100 to the first image capture unit 102 because the arrangement of the first optical axis A1 and the first image capturing axis B1 conforms to the law of reflection, and also a large amount of the emitted light of the second light source 120 to the second image capture unit 122 are reflected because the arrangement of the second optical axis A2 and the second image acquisition axis B2 also conforms to the law of reflection.

Besides, the optical inspection system is 1 This embodiment is set up in such a way that the first angle ersten between the first optical axis A1 and the first image capturing axis B1 of the first optical module 10 from the second angle Θ between the second optical axis A2 and the second image capturing axis B2 of the second optical module 12th differs so that the inspection ability of particles and short circuit problems on the DUT 2 be improved.

In one embodiment of the disclosure, the first and second angles Φ, Θ are in the range from 55 to 65 degrees, although the disclosure is not restricted in this regard.

In the embodiment of the disclosure, the first light source is located 100 and the second image capture unit 122 on one side of the normal line N (ie, on the right side of the normal line N), and the second light source 120 and the first image capture unit 102 are on another side of normal line N (ie, on the left side of normal line N). That means the first light source 100 and the second light source 120 with respect to the normal line N on two opposite sides of the DUT 2 are located. The first image capture unit 102 and the second image capture unit 122 capture images in a sequential manner. The first light source 100 emits light to the DUT 2 down, and the first image capture unit 102 simultaneously captures an image of the DUT 2 , and then the second light source emits 120 Light to the DUT 2 and the second image acquisition unit 122 simultaneously captures another image of the DUT 2 . By such an operation, even in the case that the left part of the image which is from the first image capturing unit 102 is captured, and the right part of the image which is captured by the second image capture unit 122 is detected, have shadows, the captured images are analyzed and synthesized to obtain a synthetic image without shadows. The three-dimensional shape of the DUT 2 can then be calculated from the synthetic image using an algorithm. As a result, the problem of shadowing by the inspection optical system 1 this embodiment can be solved.

In one embodiment of the disclosure, both the first and the second light source emit 100 , 120 unpolarized light. Although the first source of light 100 and the second light source 120 unpolarized light at different angles of incidence to the DUT 2 emit towards, better uniformity can be achieved.

In one embodiment of the disclosure, both the first and the second light source emit 100 , 120 polarized light To get better image contrast when analyzing certain defects or sloping surfaces, polarized light can be used.

In one embodiment of the disclosure, the light generated by the first light source 100 is emitted, a first edge pattern made up of numerous stripes on the DUT 2 and the light emitted from the second light source 120 is emitted, generates a second edge pattern made up of numerous stripes on the DUT 2 consists. Both the first edge pattern and the second edge pattern are patterns composed of a plurality of equally spaced lines. Viewed from different perspectives (ie from the first image capture unit 102 and the second image capture unit 122 off) the first edge pattern and the second edge pattern appear due to the surface shape of the DUT 2 geometrically distorted. The observed stripe patterns contain several depth information. The shifting of the stripes enables the three-dimensional coordinates of all details on the surface of the DUT to be retrieved precisely 2 . For this purpose, the individual stripes must be identified, which can be achieved, for example, by tracing or counting the stripes (pattern recognition method).

2 Fig. 13 is a schematic diagram illustrating the principle of measurement of the first edge pattern and the second edge pattern. As in 2 is shown, both the projection of the first edge pattern with a first stripe spacing P1 as well as the projection of the second edge pattern with a second stripe spacing P2 can be used individually as the smallest measuring unit, and by using the smallest measuring unit and a phase shifting method, the room height (ie the three-dimensional shape of the DUT 2 ) can be resolved in an effective manner. Currently, the three-dimensional shape of the DUT 2 are reconstructed from its reflection images based on the phase shift method. In the phase shift method, a number of at least 3, typically around 10, reflection images with slightly shifted strips recorded. The first theoretical derivations of this method were based on strips with a sinusoidal intensity modulation, but the methods also work with "rectangular" modulated strips, such as those provided by LCD or DLP displays. For example, a surface detail of 1/10 of the strip spacing can be resolved by phase shifting. These reflection images can take into account the shapes of the structured light emitted by the first light source 100 and the second light source 120 is emitted, and the height of the inspection plane P can be analyzed to determine the three-dimensional shape of the DUT 2 to reconstruct.

In the embodiment of the disclosure, the second stripe spacing differs P2 from the first strip spacing P1 . In another embodiment of the disclosure, the second is stripe spacing P2 equal to the first strip spacing P1 . By collocating the emitted light with different angles of incidence (ie the angles Φ / 2, Θ / 2 from 2 ) can be the measuring range of the optical inspection system 1 be enlarged.

3 Fig. 3 is a schematic diagram showing an optical inspection system 3 illustrated in accordance with another embodiment of the disclosure. As in 3 is shown is the optical inspection system 3 also used to be a DUT 2 to inspect. The optical inspection system 3 comprises a first optical module 30th and a second optical module 32 . The first optical module 30th includes a first light source 300 , a first image capture unit 302 and a first filter 304 . The first light source 300 has a first optical axis A1 attached to the DUT 2 is aligned. The first image capture unit 302 has a first image capture axis B1 attached to the DUT 2 is aligned. The first optical axis A1 and the first image capturing axis B1 are symmetrical with respect to a normal line N of an inspection plane P on the DUT 2 . A first angle Φ is formed between the first optical axis A1 and the first image capturing axis B1. The first filter 304 is located on the first image acquisition axis B1 and has a first transmission spectrum.

The second optical module 32 includes a second light source 320 , a second image capture unit 322 and a second filter 324 . The second light source 320 has a second optical axis A2 attached to the DUT 2 is aligned. The second image capture unit 322 has a second image capture axis B2 attached to the DUT 2 is aligned. The second optical axis A2 and the second image capturing axis B2 are symmetrical with respect to the normal line N of the inspection plane P on the DUT 2 . A second angle Θ is formed between the second optical axis A2 and the second image capturing axis B2. The second filter 324 is located on the second image acquisition axis B2 and has a second transmission spectrum which is shifted with respect to the first transmission spectrum.

The first filter 304 is set up most of the light coming from the first light source 300 is emitted to transmit, and most of the light that is from the second light source 320 is emitted to reflect, and the second filter 324 is set up most of the light coming from the first light source 300 is emitted to reflect, and most of the light emitted by the second light source 320 is emitted, transmitted. In other words, it is the transmittance of the light emitted by the first light source 300 through the first filter 304 is emitted, much higher than the transmittance of the light emitted from the second light source 320 through the first filter 304 is emitted, and the transmittance of light emitted from the first light source 300 through the second filter 324 is emitted is much lower than the transmittance of the light which is emitted from the second light source 320 through the second filter 324 is emitted.

4A Figure 13 is a graph of relative transmittance versus wavelength for the first filter 304 out 3 . 4B Figure 13 is a graph of relative transmittance versus wavelength for the second filter 324 out 3 . As in 4A and 4B is shown, it is clear that the second transmission spectrum is shifted compared to the first transmission spectrum. For example, both the first filter 304 as well as the second filter 324 39 Film layers (not shown). Each film has a specific transmission spectrum due to its specific material and thickness. The first transmission spectrum can therefore be achieved by adapting the materials or the thickness of the films of the first filter 304 can be controlled, and the second transmission spectrum can be adjusted by adjusting the materials or the thickness of the films of the second filter 324 being controlled.

5A Fig. 3 is a diagram of the relative radiant power versus wavelength with respect to the first light source 300 out 3 . 5B Figure 3 is a diagram of the relative radiant power versus wavelength with respect to the second light source 320 out 3 . As in 5A and 5B is shown has the light emitted from the first light source 300 is emitted, a first triplet R1 , G1 , B1, the one with the first transmission spectrum of the first filter 304 matches, and the light emitted from the second light source 320 is emitted, has a second triplet R2 , G2 , B2, the one with the second transmission spectrum of the second filter 324 matches. Hence, the purpose of configuring the first and second filters 304 , 324 so the first filter 304 most of the light coming from the first light source 300 is emitted, transmits and most of the light emitted by the second light source 320 is emitted, reflected, and that the second filter 324 most of the light coming from the first light source 300 is emitted, reflected and most of the light that is from the second light source 320 is emitted, transmitted, fulfilled.

With the above configuration, the first light source 300 and the second light source 320 at the same time light towards the DUT 2 emit, and the first image capture unit 302 and the second image capture unit 322 can simultaneously take pictures of the DUT 2 grasp the inspection efficiency of the optical inspection system 3 to improve.

In the embodiment of the disclosure, even in the event that the DUT 2 has a mirror surface on the inspection plane P, a large amount of the emitted light of the first light source 300 to the first image capture unit 302 because the arrangement of the first optical axis A1 and the first image capturing axis B1 conforms to the law of reflection, and also a large amount of the emitted light of the second light source 320 to the second image capture unit 322 are reflected because the arrangement of the second optical axis A2 and the second image acquisition axis B2 also conforms to the law of reflection.

Besides, the optical inspection system is 3 This embodiment is set up in such a way that the first angle ersten between the first optical axis A1 and the first image capturing axis B1 of the first optical module 30th from the second angle Θ between the second optical axis A2 and the second image capturing axis B2 of the second optical module 32 differs so that the inspection ability of particles and short circuit problems on the DUT 2 be improved.

In one embodiment of the disclosure, the first and the second angle Φ, O are in the range from 55 to 65 degrees, although the disclosure is not restricted in this regard.

In the embodiment of the disclosure, the first light source is located 300 , the second filter 324 and the second image capture unit 322 on one side of the normal line N (ie, on the right side of the normal line N), and the second light source 320 , the first filter 304 and the first image capture unit 302 are on another side of normal line N (ie, on the left side of normal line N). That means that the first light source 300 and the second light source 320 with respect to the normal line N on two opposite sides of the DUT 2 are located. As mentioned above, the first image capture unit 302 and the second image capture unit 322 capture images at the same time. With such a configuration, even in the event that the left part of the image, which from the first image capturing unit 302 is captured, and the right part of the image which is captured by the second image capture unit 322 is detected, have shadows (because the first filter 304 and the second filter 324 only allow the transmission of light, whichever is from the first light source 300 and the second light source 320 is emitted), the captured images are analyzed and synthesized to obtain a synthetic image without shadows. The three-dimensional shape of the DUT 2 can then be calculated from the synthetic image using an algorithm. Consequently, the problem of shadowing by the inspection optical system can also be raised 3 this embodiment can be solved.

In one embodiment of the disclosure, both the first and the second light source emit 300 , 320 unpolarized light. Although the first source of light 300 and the second light source 320 the unpolarized light at different angles of incidence to the DUT 2 emit, better uniformity can be achieved.

In one embodiment of the disclosure, both the first and the second light source emit 300 , 320 polarized light. Polarized light can be used to achieve better image contrast when analyzing certain defects or inclined surfaces.

In one embodiment of the disclosure, the light generated by the first light source 300 is emitted, a first edge pattern consisting of numerous stripes on the DUT 2 and the light emitted from the second light source 320 is emitted, generates a second edge pattern, which consists of numerous stripes on the DUT 2 consists. The three-dimensional shape of the DUT 2 can be reconstructed from its reflection images on the basis of the pattern recognition method and the phase shift method presented above, and so these methods are not discussed again here.

6th Fig. 3 is a schematic diagram showing an optical inspection system 5 illustrated in accordance with another embodiment of the disclosure. As in 6th is shown is the optical inspection system 5 also used to be a DUT 2 to inspect. The optical inspection system 5 comprises a first optical module 50 and a second optical module 52 . The first optical module 50 comprises a first image capture unit 500 , one first filter 502 and a first light source 504 . The first image capture unit 500 has a first image capture axis B1 attached to the DUT 2 is aligned. The first filter 502 is located on the first image acquisition axis B1 and has a first transmission spectrum. The first light source 504 is used to pass light to the first filter 502 to emit. The first filter 502 is set up most of the light coming from the first light source 504 is emitted to reflect. The reflected light from the first light source 504 has a first optical axis A1 that coincides with the first image capturing axis B1.

The second optical module 52 comprises a second image capture unit 520 , a second filter 522 and a second light source 524 . The second image capture unit 520 has a second image capture axis B2 attached to the DUT 2 is aligned. The second image capturing axis B2 and the first image capturing axis B1 are symmetrical with respect to a normal line N of an inspection plane P on the DUT 2 . The second filter 522 is located on the second image acquisition axis B2 and has a second transmission spectrum which is shifted with respect to the first transmission spectrum. The second light source 524 is used to bring light to the second filter 522 to emit. The second filter 522 is set up most of the light coming from the second light source 524 is emitted to reflect. The reflected light from the second light source 524 has a second optical axis A2 which coincides with the second image capturing axis B2.

The first filter 502 is also set up most of the light emitted from the second light source 524 is emitted to transmit, and the second filter 522 is also set up most of the light emitted from the first light source 504 emitted is transmitted. In other words, it is the transmittance of the light emitted by the first light source 504 through the second filter 522 is emitted, much higher than the transmittance of the light emitted from the second light source 524 through the second filter 522 is emitted, and the transmittance of light emitted from the first light source 504 through the first filter 502 is emitted is much lower than the transmittance of the light which is emitted from the second light source 524 through the first filter 502 is emitted.

As in 4A and 4B is shown, it is clear that the second transmission spectrum is shifted compared to the first transmission spectrum. As in 5A and 5B shows the light emitted from the first light source 504 is emitted, the first triplet R1 , G1 , B1, which coincides with the second transmission spectrum, and the light emitted by the second light source 524 is emitted, has the second triplet R2 , G2 , B2, which coincides with the first transmission spectrum. Hence, the purpose of configuring the first and second filters 502 , 522 so the first filter 502 most of the light coming from the second light source 524 is emitted, transmits and most of the light emitted by the first light source 504 is emitted, reflected, and that the second filter 522 most of the light coming from the second light source 524 is emitted, reflected and most of the light that is from the first light source 504 is emitted, transmitted, fulfilled.

With the above configuration, the first light source 504 and the second light source 524 Light at the same time to the DUT 2 emit, and the first image capture unit 500 and the second image capture unit 520 can take pictures of the DUT 2 capture at the same time, so that the inspection efficiency of the optical inspection system 5 is improved.

In the embodiment of the disclosure, even in the event that the DUT 2 has a mirror surface on the inspection plane P, a large amount of the emitted light of the first light source 504 to the second image capture unit 520 are reflected because the arrangement of the first optical axis A1 and the second image capturing axis B2 conforms to the law of reflection, and also a large amount of the emitted light of the second light source 524 to the first image capture unit 500 are reflected because the arrangement of the second optical axis A2 and the first image capturing axis B1 also conforms to the law of reflection.

In one embodiment of the disclosure, the first optical module is located 50 on one side of the normal line N (ie, on the left side of the normal line N) and the second optical module 52 is on another side of normal line N (that is, on the right side of normal line N). That means that the first light source 504 and the second light source 524 with respect to the normal line N on two opposite sides of the DUT 2 are located. As mentioned above, the first image capture unit 500 and the second image capture unit 520 capture images at the same time. With such a configuration, even in the event that the left part of the image, which from the first image capturing unit 500 was captured, and the right part of the image, which was captured by the second image capture unit 520 was captured, have shadows (because the first filter 502 and the second filter 522 allow only the transmission of light, whichever is from the second light source 524 and the first light source 504 is emitted), the captured images can be analyzed and synthesized to form a synthetic image without To get shade. The three-dimensional shape of the DUT 2 can then be calculated from the synthetic image using an algorithm. Consequently, the problem of shadowing by the inspection optical system can also be raised 5 this embodiment can be solved.

In one embodiment of the disclosure, both the first and the second light source emit 504 , 524 unpolarized light. Although the first source of light 504 and the second light source 524 the unpolarized light at different angles of incidence to the DUT 2 emit towards, better uniformity can be achieved.

In one embodiment of the disclosure, both the first and the second light source emit 504 , 524 polarized light. Polarized light can be used to obtain better image contrast when analyzing certain defects or inclined surfaces.

As in 6th is shown includes the optical inspection system 5 also a third optical module 54 and a fourth optical module 56 . The third optical module 54 comprises a third image capture unit 540 , a third filter 542 and a third light source 544 . The third image capture unit 540 has a third axis of image capture B3 who work on the DUT 2 is aligned. The third filter 542 is on the third axis of image capture B3 and has the first transmission spectrum. The third light source 544 is used to pass light to the third filter 542 to emit. The third filter 542 is furnished with most of the light coming from the third light source 544 is emitted to reflect. The reflected light from the third light source 544 has a third optical axis A3 that is with the third axis of image capture B3 matches. The fourth optical module 56 comprises a fourth image capture unit 560 , a fourth filter 562 and a fourth light source 564 . The fourth image capture unit 560 has a fourth axis of image capture B4 who work on the DUT 2 is aligned. The fourth axis of image capture B4 and the third image capture axis B3 are symmetrical with respect to the normal line N. The fourth filter 562 is on the fourth axis of image capture B4 and has the second transmission spectrum. The fourth light source 564 is used to pass light to the fourth filter 562 to emit. The fourth filter 562 is set up to reflect most of the light coming from the fourth light source 564 is emitted. The reflected light from the fourth light source 564 has a fourth optical axis A4 that is with the fourth axis of image capture B4 matches.

It should be noted that the third filter 542 it is set up to transmit most of the light coming from the fourth light source 564 is emitted, and also the fourth filter 562 it is set up to transmit most of the light coming from the third light source 544 is emitted. In other words, it is the transmittance of the light emitted by the third light source 544 through the fourth filter 562 is emitted, much higher than the transmittance of the light emitted from the fourth light source 564 through the fourth filter 562 is emitted, and the transmittance of light emitted from the third light source 544 through the third filter 542 is emitted is much lower than the transmittance of the light which is emitted from the fourth light source 564 through the third filter 542 is emitted.

As in 4A and 4B is shown, it is clear that the second transmission spectrum is shifted compared to the first transmission spectrum. What 5A and 5B as far as that is concerned, the light emitted by the third light source 544 is emitted, the first triplet R1 , G1 , B1, which coincides with the second transmission spectrum, and the light emitted from the fourth light source 564 is emitted, has the second triplet R2 , G2 , B2, which coincides with the first transmission spectrum. Hence, the purpose of configuring the third filter 542 so that the third filter 542 most of the light coming from the fourth light source 564 is emitted, transmits, and most of the light that is emitted from the third light source 544 is emitted, reflected, and the configuration of the fourth filter 562 so the fourth filter 562 most of the light coming from the fourth light source 564 is emitted, reflected and most of the light that is from the third light source 544 is emitted, transmitted, fulfilled.

With the above configuration, the third light source 544 and the fourth light source 564 at the same time light to the DUT 2 emit out, and the third image capture unit 540 and the fourth image capture unit 560 can simultaneously take pictures of the DUT 2 grasp, so that the inspection efficiency of the optical inspection system 5 is improved.

In the embodiment of the disclosure, even in the event that the DUT 2 has a mirror surface on the inspection plane P, a large amount of the emitted light of the third light source 544 to the fourth image acquisition unit 560 be reflected because the arrangement of the third optical axis A3 and the fourth axis of image capture B4 with the law of reflection, and also a large amount of the emitted light of the fourth light source 564 to the third image capture unit 540 be reflected because the arrangement of the fourth optical axis A4 and the third image capture axis B3 also agrees with the law of reflection.

In one embodiment of the disclosure, the third optical module is located 54 on one side of the normal line N (ie, on the right side of the normal line N), and the fourth optical module 56 is on another side of normal line N (ie, on the left side of normal line N). That means the third light source 544 and the fourth light source 564 with respect to the normal line N on two opposite sides of the DUT 2 are located. As mentioned above, the third image capture unit 540 and the fourth image capture unit 560 capture images at the same time. With such a configuration, even in the event that the right part of the image which is from the third image capturing unit 540 was captured, and the left part of the image, which was captured by the fourth image capture unit 560 was captured, have shadows (because the third filter 542 and the fourth filter 562 Allow only the transmission of light from each of the fourth light sources 564 and the third light source 544 is emitted), the captured images are analyzed and synthesized to obtain a synthetic image without shadows. The three-dimensional shape of the DUT 2 can then be calculated from the synthetic image using an algorithm. Consequently, the problem of shadowing by the inspection optical system can also be raised 5 this embodiment can be solved.

In one embodiment of the disclosure, a first angle Φ is formed between the first image capturing axis B1 and the second image capturing axis B2. A second angle Θ is made between the third image capture axis B3 and the fourth axis of image capture B4 is formed, and the second angle Θ is different from the first angle Φ. The optical inspection system 5 This embodiment is set up in such a way that the first angle Φ between the first image capturing axis B1 of the first optical module 50 and the second image capturing axis B2 of the second optical module 52 from the second angle Θ between the third image capture axis B3 of the third optical module 54 and the fourth axis of image capture B4 of the fourth optical module 56 differs so that the inspection ability of particles and short circuit problems on the DUT 2 is improved.

In one embodiment of the disclosure, the first and the second angles Φ, Θ are in the range from 55 to 65 degrees, although the disclosure is not restricted in this regard.

In one embodiment of the disclosure, both the third and the fourth light source emit 544 , 564 unpolarized light. Although the third source of light 544 and the fourth light source 564 unpolarized light at different angles of incidence to the DUT 2 emit towards, better uniformity can be achieved.

In one embodiment of the disclosure, both the third and the fourth light source emit 544 , 564 polarized light. Polarized light can be used to obtain better image contrast when analyzing certain defects and inclined surfaces.

It should be noted that in the optical inspection system 5 In this embodiment, four sets of optical modules can be used, so that more information can be obtained in this embodiment than in the embodiment from FIG 3 .

According to the foregoing of the embodiments of the disclosure, it can be seen that the inspection optical system of the disclosure arranges the optical axis of each of the light sources and the image capturing axis of the corresponding image capturing unit so that they are symmetrical with respect to the normal line of the inspection plane so that even if the DUT has a mirror surface at the inspection plane, a large amount of the emitted light from each light source can be reflected to the corresponding image acquisition unit. Furthermore, in the optical inspection system of the disclosure, the light sources are each positioned on two opposite sides of the DUT with respect to the normal line, so that even in the event that the images captured by the image capture units have shadows at different locations, the Images can be further analyzed and synthesized to obtain a synthetic image without shadows, and so the problem of shadows can be solved. In addition, the optical inspection system of the disclosure is arranged so that the angle between the optical axis and the associated image capturing unit in one optical module is different from that in another optical module, so that the inspection ability of particles and short circuit problems are improved. Furthermore, the measuring range of the optical inspection system can be enlarged by adapting the above-mentioned angles. In addition, by using filters each of which allows only most of the light emitted from the corresponding light source to be transmitted, all of the image capturing units can capture images simultaneously, so that the inspection efficiency of the optical inspection system is improved.

Although the present disclosure has been described in detail with reference to certain embodiments thereof, other embodiments are possible. Therefore, the spirit and scope of the appended claims should not be limited to the description of the embodiments contained herein.

One skilled in the art will be aware that various modifications and variations can be made to the structure of the present disclosure without departing from the scope or spirit of the disclosure. In view of the foregoing, it is intended that the present disclosure cover modifications and variations of this disclosure insofar as they fall within the scope of the following claims.

Claims (20)

Optical inspection system (1) for inspecting a measurement object (2) with: - a first optical module (10) comprising: a first light source (100) which has a first optical axis (A1) and which emits light towards the measurement object (2), a first image acquisition unit (102) simultaneously acquiring an image of the measurement object (2), the first image acquisition unit (102 ) has a first image acquisition axis (B1) and the first optical axis (A1) and the first image acquisition axis (B1) are symmetrical with respect to a normal line (N) of an inspection plane (P) on the measurement object (2) and a first angle (Φ ) is formed between the first optical axis (A1) and the image capture axis (B); and - a second optical module (12) comprising: a second light source (120) which has a second optical axis (A2) and emits light towards the measurement object (2), a second image capturing unit (122) simultaneously capturing an image of the measurement object (2), the second image capturing unit (122) has a second image acquisition axis (B2) and the second optical axis (A2) and the second image acquisition axis (B2) are symmetrical with respect to the normal line (N) and a second angle (Θ) which differs from the first angle (Φ), is formed between the second optical axis (A2) and the second image capturing axis (B2). Optical inspection system (1) according to Claim 1 wherein the first light source (100) and the second image capturing unit (122) are on one side of the normal line (N), and the second light source (120) and the first image capturing unit (102) are on another side of the normal line (N) are located. Optical inspection system (1) according to Claim 1 , wherein the first and second angles (Φ, Θ) are in the range of 55 to 65 degrees. Optical inspection system (1) according to Claim 1 wherein the first and second light sources (100, 120) emit unpolarized light or polarized light. Optical inspection system (1) according to Claim 1 , wherein light that is emitted by the first light source (100) generates a first edge pattern on the measurement object (2), the first edge pattern has a first stripe spacing (P1), light that is emitted by the second light source (120), a second edge pattern is generated on the measurement object (2), and the second edge pattern has a second stripe spacing (P2) which is equal to the first stripe spacing (P1). Optical inspection system (1) according to Claim 1 , wherein light that is emitted by the first light source (100) generates a first edge pattern on the measurement object (2), the first edge pattern has a first stripe spacing (P1), light that is emitted by the second light source (120), a second edge pattern is generated on the measurement object (2), and the second edge pattern has a second stripe spacing (P2) which differs from the first stripe spacing (P1). An optical inspection system (3) for inspecting a measurement object (2), the optical inspection system (3) comprising: a first optical module (30) comprising: a first light source (300) having a first optical axis (A1); a first image acquisition unit (302) having a first image acquisition axis (B1), the first optical axis (A1) and the first image acquisition axis (B1) in relation to a normal line (N) of an inspection plane (P) on the measurement object (2) are symmetrical, and a first angle (Φ) is formed between the first optical axis (A1) and the first image capturing axis (B1); and a first filter (304) located on the first image capture axis (B1) and having a first transmission spectrum; and a second optical module (32) comprising: a second light source (320) having a second optical axis (A2); a second image capturing unit (322) having a second image capturing axis (B2), the second optical axis (A2) and the second image capturing axis (B2) being symmetrical with respect to the normal line N), a second angle (Θ) between the second optical axis (A2) and the second image acquisition axis (B2) is formed, and the second angle (Θ) is different from the first angle (Φ); and a second filter (324) which is located on the second image acquisition axis (B2) and has a second transmission spectrum which is shifted compared to the first transmission spectrum, the first filter (304) being set up to transmit most of the light emitted by the first light source (300) and to reflect most of the light emitted by the second light source (320) and the second filter (324) is set up to reflect most of the light which is emitted by the first light source (300) and to transmit most of the light which is emitted by the second light source (320). Optical inspection system (3) according to Claim 7 , wherein the light which is emitted by the first light source (300) has a first triplet (R1, G1, B1) which corresponds to the first transmission spectrum, and the light which is emitted by the second light source (320), a second triplet (R2, G2, B2) which corresponds to the second transmission spectrum. Optical inspection system (3) according to Claim 7 , wherein the first light source (300), the second filter (324) and the second image capturing unit (322) are on one side of the normal line (N), and the second light source (320), the first filter (304) and the first image acquisition unit (302) are on another side of the normal line (N). Optical inspection system (3) according to Claim 7 , wherein the first and second angles (Φ, Θ) are in the range of 55 to 65 degrees. Optical inspection system according to Claim 7 wherein the first and second light sources (300, 320) emit unpolarized light or polarized light. Optical inspection system (5) for inspecting a measurement object (2), the optical inspection system (5) comprising: a first optical module (50) comprising: a first image capturing unit (50) having a first image capturing axis (B1); a first filter (502) which is located on the first image acquisition axis (B1) and has a first transmission spectrum; and a first light source (504) for emitting light to the first filter (502), wherein the first filter (502) is arranged to reflect most of the light emitted by the first light source (504), and wherein the reflected light the first light source (504) has a first optical axis (A1) which coincides with the first image capturing axis (B1); a second optical module (52) comprising: a second image acquisition unit (520) having a second image acquisition axis (B2), the second image acquisition axis (B2) and the first image acquisition axis (B1) being symmetrical with respect to a normal line (N) of an inspection plane (P) on the measurement object (2) are; a second filter (522) which is located on the second image acquisition axis (B2) and has a second transmission spectrum which is shifted with respect to the first transmission spectrum; and a second light source (524) for emitting light to the second filter (522), wherein the second filter (522) is set up to reflect most of the light emitted by the second light source (524), and the reflected light of the second light source (524) has a second optical axis (A2) which coincides with the second image capture axis (B2); wherein the first filter (502) is further configured to transmit most of the light emitted by the second light source (524), and the second filter (522) is further configured to transmit most of the light emitted by the first light source (504). is emitted, is established. Optical inspection system (5) according to Claim 12 , wherein the light which is emitted from the first light source (504) has a first triplet (R1, G1, B1) which corresponds to the second transmission spectrum, and the light which is emitted from the second light source (524), a second triplet (R2, G2, B2) which corresponds to the first transmission spectrum. Optical inspection system (5) according to Claim 12 wherein the first optical module (50) is on one side of the normal line (N) and the second optical module (52) is on another side of the normal line (N). Optical inspection system (5) according to Claim 12 wherein the first and second light sources (504, 524) emit unpolarized light or polarized light. Optical inspection system (5) according to Claim 12 , wherein a first angle (Φ) is formed between the first image capturing axis (B1) and the second image capturing axis (B2), and the optical inspection system (5) further comprises: a third optical module (54) comprising: a third image capturing unit (540 ) having a third image capture axis (B3); a third filter (542) located on the third image capture axis (B3) and having the first transmission spectrum; and a third light source (544) for emitting light to the third filter (542), wherein the third filter (542) is adapted to reflect most of the light emitted by the third light source (544), and the reflected light of the the third light source (544) has a third optical axis (A3) which coincides with the third image capture axis (B3); a fourth optical module (56) comprising: a fourth image capturing unit (560) having a fourth image capturing axis (B4), the fourth image capturing axis (B4) and the third image capturing axis (B3) being symmetrical with respect to the normal line (N) , a second angle (Θ) is formed between the third image acquisition axis (B3) and the fourth image acquisition axis (B4), and the second angle (Θ) differs from the first angle (Φ); a fourth filter (562) located on the fourth image capture axis (B4) and having the second transmission spectrum; and a fourth light source (564) for emitting light to the fourth filter (562), the fourth filter (562) being arranged to reflect most of the light emitted by the fourth light source (564) and the reflected light the fourth light source (564) has a fourth optical axis (A4) which coincides with the fourth image capture axis (B4); wherein the third filter (542) is further configured to transmit most of the light emitted by the fourth light source (564), and wherein the fourth filter (562) is further configured to transmit most of the light emitted by the third light source (544 ) is issued. Optical inspection system (5) according to Claim 16 , wherein the light which is emitted by the third light source (544) has a first triplet (R1, G1, B1) which corresponds to the second transmission spectrum, and the light which is emitted by the fourth light source (564), a second triplet (R2, G2, B2) which corresponds to the first transmission spectrum. Optical inspection system (5) according to Claim 16 wherein the third optical module (54) is on one side of the normal line (N) and the fourth optical module (56) is on another side of the normal line (N). Optical inspection system (5) according to Claim 16 , wherein the first and second angles (Φ, Θ) are in the range of 55 to 65 degrees. Optical inspection system according to Claim 16 wherein the third and fourth light sources (544, 564) emit unpolarized light or polarized light.

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