TWI893836B - Defect detection method and system based on photoelasticity - Google Patents

Abstract

A defect detection method based on photoelasticity including: placing an object to be tested on a base. Providing a laser device. The laser device emits a first laser beam toward a detection portion of the object to be tested. A first photoelastic sensor is provided. The first photoelastic sensor receives a first reflected light reflected by a detection portion of the object to be tested to generate a first reflected light signal, or receives a first transmitted light passes through the detection portion of the object to be tested to generate a first transmitted light signal. An imaging device is provided and electrically connected to the first photoelastic sensor. The imaging device receives the first reflected light signal or the first transmitted light signal and generates a first stress distribution characteristic map. The invention also provides a defect detection system based on photoelasticity.

Description

Photoelasticity-based defect detection method and system

The present invention relates to a method and system for defect detection, and in particular to a method and system for photoelastic defect detection.

As semiconductor manufacturing processes become increasingly sophisticated with technological advancements, defect detection for chips and packages is becoming increasingly important. Due to the precision of the manufacturing process, the chips and packages are small and numerous, making it difficult to detect defects.

Therefore, improving inspection technology to enhance the inspection performance and accuracy of test objects (such as chips, wafers, or dies) and provide feedback to improve the manufacturing process and increase production yield has become one of the key issues that the industry aims to address.

The present invention addresses the shortcomings of existing technologies by providing a photoelasticity-based defect detection method. The method comprises: placing an object under test on a base; providing a laser device comprising a collimator, a polarizer, and a laser light source. The laser device is positioned on a first side of the object under test and emits a first laser beam toward a detection portion of the object under test; providing a first photoelasticity sensor that receives first reflected light from the first laser beam reflected by the detection portion of the object under test to generate a first reflected light signal, or receives first transmitted light from the first laser beam that passes through the detection portion of the object under test to generate a first transmitted light signal; and providing an imaging device electrically connected to the first photoelasticity sensor that receives the first reflected light signal or the first transmitted light signal to generate a first stress distribution characteristic map.

According to one feasible embodiment, the photoelasticity-based defect detection method further includes providing a second photoelastic sensor, located on a second side of the object to be tested. The first photoelastic sensor is located on the first side. When the first photoelastic sensor receives first reflected light to generate a first reflected light signal, the laser device also emits a second laser beam toward the detection portion of the object to be tested. The second photoelastic sensor receives second transmitted light from the second laser beam that passes through the portion of the object to be tested to generate a second transmitted light signal. An imaging device receives the second transmitted light signal and generates a second stress distribution characteristic map.

According to one feasible embodiment, the photoelasticity-based defect detection method further includes providing a second photoelastic sensor electrically connected to an imaging device, the second photoelastic sensor being located on a first side of the object to be tested. The first photoelastic sensor is located on a second side of the object to be tested. When the first photoelastic sensor receives the first transmitted light to generate a first transmitted light signal, the laser device also emits a second laser beam toward a detection portion of the object to be tested. The second photoelastic sensor receives second reflected light from the second laser beam reflected by the detection portion of the object to generate a second reflected light signal. The imaging device receives the second reflected light signal and generates a second stress distribution characteristic map.

According to one feasible embodiment, the photoelasticity-based defect detection method further includes: providing a laser moving device connected to the laser device, the laser moving device being configured to move the laser device in a three-dimensional space; and providing a first moving device connected to the first photoelastic sensor, the first moving device being configured to move the first photoelastic sensor in the three-dimensional space.

According to one feasible embodiment, the photoelasticity-based defect detection method further includes providing a second moving device connected to the second photoelastic sensor, wherein the second moving device is configured to move the second photoelastic sensor in three-dimensional space.

According to one feasible embodiment, the photoelasticity-based defect detection system further includes: an imaging device capturing multiple images of a shadowed portion of the inspection area that is not exposed to the first laser beam and providing them to an analysis module; receiving the multiple images, determining and calculating the defects and probability of the shadowed portion based on the multiple images; or compensating the multiple images to determine and calculate the defects and probability of the shadowed portion.

The present invention also provides a system for defect detection based on photoelasticity, which includes a control device, a base, a laser device, a first photoelastic sensor, and an imaging device. The base supports the object to be tested. The laser device is electrically connected to the control device, and the laser device includes a collimator, a polarizer, and a laser light source. The laser device is located on the first side of the object to be tested and emits a first laser beam toward the detection part of the object to be tested; the first photoelastic sensor is electrically connected to the control device, and the first photoelastic sensor receives the first reflected light reflected by the first laser beam from the detection part of the object to be tested to generate a first reflected light signal, or receives the first transmitted light of the first laser beam passing through the detection part of the object to be tested to generate a first transmitted light signal. The imaging device is electrically connected to the control device and the first photoelastic sensor, and the imaging device receives the first reflected light signal or the first transmitted light signal to generate a first stress distribution characteristic map.

According to one feasible embodiment, the photoelasticity-based defect detection system further includes a second photoelastic sensor electrically connected to a control device and an imaging device. The second photoelastic sensor is located on the second side of the object under test. The first photoelastic sensor is located on the first side. When the first photoelastic sensor receives the first reflected light to generate a first reflected light signal, the laser device also emits a second laser beam toward the inspection portion of the object under test. The second photoelastic sensor receives the second transmitted light from the second laser beam that passes through the portion of the object under test to generate a second transmitted light signal. The imaging device receives the second transmitted light signal and generates a second stress distribution characteristic map.

According to one feasible embodiment, a photoelasticity-based defect detection system further includes a second photoelastic sensor electrically connected to a control device and an imaging device. The second photoelastic sensor is located on a first side of the object under test. When the first photoelastic sensor receives the first transmitted light to generate a first transmitted light signal, a laser device also emits a second laser beam toward a detection portion of the object under test. The second photoelastic sensor receives second reflected light from the detection portion of the object under test to generate a second reflected light signal. The imaging device receives the second reflected light signal and generates a second stress distribution characteristic map.

According to one feasible embodiment, the photoelasticity-based defect detection system further includes a laser moving device and a first moving device. The laser moving device is electrically connected to the control device and the laser device, and is used to move the laser device in three-dimensional space. The first moving device is electrically connected to the control device and the first photoelastic sensor, and is used to move the first photoelastic sensor in three-dimensional space.

According to one feasible embodiment, the photoelasticity-based defect detection system further includes a second moving device electrically connected to the control device and the second photoelastic sensor. The second moving device is configured to move the second photoelastic sensor in three-dimensional space.

According to one possible embodiment, the control device includes an analysis module. The imaging device captures multiple images of the shadowed portion of the inspection area that is not exposed to the first laser beam. The analysis module receives the multiple images and, based on the multiple images, determines and calculates the defects and probability of the shadowed portion. Alternatively, the analysis module compensates for the multiple images and determines and calculates the defects and probability of the shadowed portion.

One of the beneficial effects of the present invention is that the photoelasticity-based defect detection method and system provided by the present invention can improve the accuracy of defect detection results through the technical solutions of "a first photoelastic sensor receiving first reflected light from a first laser beam reflected by a detection portion of the object to be tested to generate a first reflected light signal, or receiving first transmitted light from the first laser beam passing through the detection portion of the object to be tested to generate a first transmitted light signal" and "an imaging device receiving the first reflected light signal or the first transmitted light signal to generate a first stress distribution characteristic map."

Furthermore, by installing a second photoelastic sensor, users can initially detect whether the object under test contains the aforementioned defects using a first stress distribution signature generated by reflected light. The second stress distribution signature generated by transmitted light can then be used to re-detect or confirm the object's condition, thereby improving the accuracy of the test results.

Furthermore, by installing a second photoelastic sensor, users can initially detect whether the object under test contains the aforementioned defects using a first stress distribution signature generated by transmitted light. The second stress distribution signature generated by reflected light can then be used to re-detect or confirm the condition of the object under test, thereby improving the accuracy of the test results.

To further understand the features and technical contents of the present invention, please refer to the following detailed description and drawings of the present invention. However, the drawings provided are for reference and illustration only and are not intended to limit the present invention.

Z1-Z4: Photoelasticity-based defect detection system

11: Control device

12: Base

13: Laser device

131: Collimator

132: Laser Light Source

133: Polarizer

14: First photoelastic sensor

15: Imaging Device

16: Object to be tested

17: Second photoelastic sensor

R1: First reflected light

R2: Second reflected light

L1: First penetrating light

L2: Second penetrating light

S1: First side

S2: Second side

100-300: Photoelasticity-based defect detection method

S10-S15: Steps

S20-S26: Steps

S30-S36: Steps

Figures 1 to 3 are schematic flow charts of a photoelasticity-based defect detection method according to an embodiment of the present invention.

Figures 4 to 7 are schematic diagrams of the system architecture of photoelasticity-based defect detection according to an embodiment of the present invention.

The following describes the implementation of the "Photoelasticity-Based Defect Detection Method and System" disclosed herein through specific embodiments. Those skilled in the art will appreciate the advantages and benefits of this invention from the disclosure herein. This invention may be implemented or applied through various other specific embodiments, and the details herein may be modified and altered based on different perspectives and applications without departing from the spirit of this invention. The accompanying figures are for schematic illustration only and are not intended to be drawn to actual size. This is to be noted. The following embodiments further illustrate the relevant technical aspects of this invention, but the disclosure is not intended to limit the scope of protection of this invention.

Please refer to Figure 1, which is a schematic flow diagram of a photoelasticity-based defect detection method 100 according to an embodiment of the present invention, which includes steps S10 to S13.

Step S10: Place the object to be tested on the base.

Step S11: Providing a laser device comprising a collimator, a polarizer, and a laser light source. The laser device is positioned on a first side of the object to be tested and emits a first laser beam toward a detection portion of the object to be tested. According to some embodiments, the laser device scans the detection portion with the first laser beam.

Step S12: Providing a first photoelastic sensor. The first photoelastic sensor receives first reflected light from the first laser beam reflected from the detection portion of the object to be tested to generate a first reflected light signal, or receives first transmitted light from the first laser beam passing through the detection portion of the object to be tested to generate a first transmitted light signal.

Step S13: Providing an imaging device electrically connected to the first photoelastic sensor. The imaging device receives the first reflected light signal or the first transmitted light signal and generates a first stress distribution characteristic map. The imaging device can be a camera or any device capable of capturing images.

According to some embodiments, the base can be a transparent plate such as glass or sapphire. According to some embodiments, the base is a movable base having a drive motor. According to some other embodiments, the base includes a conveyor belt carrying a plurality of objects to be tested.

According to some embodiments, the object to be tested is, for example, a wafer, chip, or die. According to other embodiments, the object to be tested may be a package (finished or semi-finished product). According to other embodiments, the object to be tested is located on a substrate (such as a circuit board) supported by a base. The inspection location may be, for example, a surface, a hole, a via, or a solder structure (solder area), but the present invention is not limited thereto. Using the first stress distribution characteristic map, the user can view the stress distribution at the inspection location to determine whether the object to be tested is a good product. For example, the stress distribution can be divided into a good area, a stress-generating area, and a good-quality area. The good-quality area may have defects such as cracks, uneven surfaces, or detached solder structures. Based on the stress distribution, the user can identify and resolve the problem at the defective location.

Taking through-hole vias (TGV or TSV) as an example, common defects include burrs and unevenness on the inner wall, through-hole channel deviation, incorrect angle between the through-hole and the substrate, through-hole failure to penetrate the substrate, and incorrect size or shape. Stress distribution can be used to identify which of these defects may be present and identify process-specific solutions.

Please refer to Figure 2, which is a schematic flow chart of a photoelasticity-based defect detection method 200 according to one embodiment of the present invention. The photoelasticity-based defect detection method 200 includes steps S20 through S26. In this embodiment, the photoelasticity-based defect detection method further includes steps S24 and S26. Step S24 includes providing a second photoelastic sensor, which is positioned on the second side of the object under test. The first photoelastic sensor is located on the first side. When the first photoelastic sensor receives the first reflected light and generates a first reflected light signal, step S25 is executed: the laser device also emits a second laser beam toward the inspection portion of the object to be inspected. The second photoelastic sensor receives the second transmitted light from the second laser beam that passes through the inspection portion of the object to generate a second transmitted light signal. Then, step S26 is executed: the imaging device receives the second transmitted light signal and generates a second stress distribution signature. In this embodiment, the user can first perform a preliminary inspection to determine whether the object to be inspected contains the aforementioned defects using the first stress distribution signature generated by the reflected light, and then re-inspect or confirm the inspection status of the object to be inspected based on the second stress distribution signature generated by the transmitted light, thereby improving inspection process efficiency.

Please refer to Figure 3, which is a flow chart of a photoelasticity-based defect detection method 300 according to one embodiment of the present invention. The photoelasticity-based defect detection method 300 includes steps S30 to S36. In this embodiment, step S34 includes providing a second photoelasticity sensor electrically connected to an imaging device, and the second photoelasticity sensor is located on a first side of the object to be tested. The first photoelasticity sensor is located on the second side of the object to be tested. When the first photoelasticity sensor receives the first transmitted light to generate a first transmitted light signal, step S35 is executed: the laser device also emits a second laser beam toward the detection portion of the object to be tested, and the second photoelasticity sensor receives the second reflected light reflected by the second laser beam from the detection portion of the object to be tested to generate a second reflected light signal. Next, step S36 is executed: the imaging device receives the second reflected light signal and generates a second stress distribution characteristic map. In this embodiment, the user can first use the first stress distribution characteristic map generated by the transmitted light to preliminarily detect whether the object under test contains the aforementioned defects. The second stress distribution characteristic map generated by the reflected light can then be used to re-inspect or confirm the inspection status of the object under test, thereby improving inspection process efficiency.

According to some embodiments, the photoelasticity-based defect detection method further includes providing a laser moving device connected to the laser device, the laser moving device being configured to move the laser device in three-dimensional space. Furthermore, providing a first moving device connected to the first photoelasticity sensor being configured to move the first photoelasticity sensor in three-dimensional space. In this manner, the laser device can be moved to emit a laser beam directed at a specific inspection location on the object to be inspected. Conversely, the first photoelasticity sensor can also be moved relative to the laser beam to a position where it can receive the first reflected light or the first transmitted light.

According to some embodiments, the photoelasticity-based defect detection method also includes providing a second moving device connected to the second photoelastic sensor, the second moving device being configured to move the second photoelastic sensor in three-dimensional space. By connecting to the second moving device, the second photoelastic sensor can be moved to a position for receiving the second reflected light or the second transmitted light.

According to some embodiments, the wavelength of the first laser beam and the second laser beam ranges from 300 nm to 2000 nm. The pulse width of the first laser beam and the second laser beam ranges from 50 fs to 50 ns.

However, the present invention is not limited to this. The projection angles of the first and second laser beams can be adjusted based on the location of the inspection area or the material being inspected. Furthermore, in some embodiments, the wavelengths of the first and second laser beams can be adjusted to suit different materials being inspected, thereby improving inspection accuracy.

Referring again to Figure 1, this embodiment also includes steps S14 and S15. In step S14, the imaging device captures multiple images of the shadowed portion of the inspection area that is not receiving the first laser beam. In step S15, the analysis module receives the multiple images and determines and calculates the defects and probabilities of the shadowed portion based on the multiple images; or alternatively, the analysis module compensates for the multiple images and determines and calculates the defects and probabilities of the shadowed portion. The imaging device captures the shadowed portion (inspection area) of the object to be inspected, specifically the portion that is not receiving the first laser beam (or second laser beam). The analysis module, such as a computer, can determine the potential defects and the probability of the defects in the shadowed portion through deep learning. The analysis module can further determine and calculate the defects and probabilities in the shadow area by compensating the image.

Please refer to Figure 4, which shows the architecture of a photoelasticity-based defect detection system Z1 according to one embodiment of the present invention. The photoelasticity-based defect detection system Z1 includes a control device 11, a base 12, a laser device 13, a first photoelasticity sensor 14, and an imaging device 15. The base 12 supports an object 16 to be tested. The laser device 13 is electrically connected to the control device 11 and includes a collimator 131, a laser light source 132, and a polarizer 133. The laser device 13 is positioned on a first side S1 of the object 16 to be tested and emits a first laser beam toward the detection portion of the object 16 to be tested. The first photoelastic sensor 14 is electrically connected to the control device 11. The first photoelastic sensor 14 receives the first reflected light R1 from the first laser beam reflected by the detection portion of the object 16 to generate a first reflected light signal. The imaging device 15 is electrically connected to the control device 11 and the first photoelastic sensor 14. The imaging device 15 receives the first reflected light signal and generates a first stress distribution characteristic map.

For details about the base 12, the object under test 16, the testing location, and the first stress distribution characteristic diagram, please refer to the above description.

Please refer to Figure 5, which shows a photoelasticity-based defect detection system Z2 according to one embodiment of the present invention. This system differs from the embodiment shown in Figure 4 in that a first photoelastic sensor 14 receives first transmitted light L1 from a first laser beam that passes through the detection area of an object under test 16, generating a first transmitted light signal. An imaging device 15 receives the first transmitted light signal and generates a first stress distribution characteristic map.

Please refer to Figure 6, which illustrates a photoelasticity-based defect detection system Z3 according to one embodiment of the present invention. In this embodiment, the photoelasticity-based defect detection system Z4 further includes a second photoelastic sensor 17, electrically connected to the control device 11 and the imaging device 15. The second photoelastic sensor 17 is located on the second side S2 of the object under test 16. The first photoelastic sensor 14 is located on the first side S1. While the first photoelastic sensor 14 receives the first reflected light R1 to generate a first reflected light signal, the laser device 13 also emits a second laser beam toward the detection portion of the object under test 16. The second photoelastic sensor 17 receives the second transmitted light L2 from the second laser beam that passes through the portion of the object under test 16 to generate a second transmitted light signal. The imaging device 15 receives the second transmitted light signal and generates a second stress distribution characteristic map. In this embodiment, the user can first perform a preliminary inspection of the object under test 16 to determine whether it contains the aforementioned defects using a first stress distribution characteristic map formed by reflected light. The user can then re-inspect or confirm the inspection status of the object under test 16 based on a second stress distribution characteristic map formed by transmitted light, thereby improving the accuracy of the inspection results.

Please refer to Figure 7, which shows a photoelasticity-based defect detection system Z4 according to one embodiment of the present invention. According to this embodiment, the photoelasticity-based defect detection system further includes a second photoelasticity sensor 17, which is electrically connected to the control device 11 and the imaging device 15. The second photoelasticity sensor 17 is located on the first side S1 of the object to be tested 16. The first photoelastic sensor 14 is located on the second side S2 of the object under test 16. While the first photoelastic sensor 14 receives the first transmitted light L1 and generates a first transmitted light signal, the laser device 13 also emits a second laser beam toward the detection portion of the object under test 16. The second photoelastic sensor 17 receives the second reflected light R2 reflected by the detection portion of the object under test 16 and generates a second reflected light signal. The imaging device 15 receives the second reflected light signal and generates a second stress distribution signature. In this embodiment, the user can first perform a preliminary inspection of the object under test 16 to determine whether it contains the aforementioned defects using the first stress distribution signature generated by the transmitted light. The user can then re-inspect or confirm the inspection status of the object under test 16 based on the second stress distribution signature generated by the reflected light, thereby improving the accuracy of the inspection results.

According to some embodiments, the photoelasticity-based defect detection system further includes a laser moving device and a first moving device (not shown). The laser moving device is electrically connected to the control device 11 and the laser device 13, and is used to move the laser device 13 in three-dimensional space. The first moving device is electrically connected to the control device 11 and the first photoelasticity sensor 14, and is used to move the first photoelasticity sensor 14 in three-dimensional space. In this way, the laser device 13 can be moved in three-dimensional space to emit a laser beam at a specific inspection location on the object 16 to be inspected. Conversely, the first photoelasticity sensor 14 can also be moved relative to the laser beam to a position where it can receive the first reflected light R1 or the first transmitted light L1.

According to some embodiments, the photoelasticity-based defect detection system further includes a second moving device (not shown) electrically connected to the control device 11 and the second photoelasticity sensor 17. The second moving device is configured to move the second photoelasticity sensor 17 in three-dimensional space. By connecting to the second moving device, the second photoelasticity sensor 17 can be moved to a position for receiving the second reflected light R2 or the second transmitted light L2.

According to some embodiments, the control device includes an analysis module (not shown). The imaging device captures multiple images of the shadow portion of the detection part that does not receive the first laser beam. The analysis module receives the multiple images and judges and calculates the defects and probabilities of the shadow portion based on the multiple images. The analysis module may compensate for the multiple images and judge and calculate the defects and probabilities of the shadow portion. The imaging device captures the shadow portion of the detection part of the object to be tested, especially the portion that cannot receive the first laser beam (or the second laser beam). The analysis module, such as a computer, can judge the possible defects of the shadow portion and the probability of the occurrence of the defect through deep learning. The analysis module may further judge and calculate the defects and probabilities of the shadow portion by compensating the image. With this arrangement, the accuracy of defect detection can be improved.

It should be noted that the wavelength of the laser beam emitted by the laser device 13 of the present invention can be adjusted based on the detection distance (the distance between the laser device 13 and the object 16 to be detected) and the characteristics of the desired detection area (such as the aforementioned cracks, holes, perforations, bonds, uneven surfaces, etc.). This invention is not limited to this.

It should also be noted that, according to some embodiments, the base 12 is a transmissive platform. Thus, the first penetrating light L1 and the second penetrating light L2 are not affected by the base 12 and pass through.

It should also be noted that in some embodiments, the first laser beam and the second laser beam can be distinguished as the same laser beam or different laser beams, depending on the material of the object 16 to be tested or the location of the detection area.

[Beneficial Effects of the Embodiment]

One of the benefits of the present invention is that the photoelasticity-based defect detection method and system provided by the present invention utilize the technical solutions of "a first photoelastic sensor receiving first reflected light from a first laser beam reflected from a detection portion of the object to be tested to generate a first reflected light signal, or receiving first transmitted light from the first laser beam passing through the detection portion of the object to be tested to generate a first transmitted light signal," and "an imaging device receiving the first reflected light signal or the first transmitted light signal to generate a first stress distribution characteristic map." This method can distinguish defects based on stress distribution, thereby improving the accuracy of defect detection results. Furthermore, it can also identify solutions to defects in the manufacturing process.

Furthermore, by installing a second photoelastic sensor, users can initially detect whether the object under test contains the aforementioned defects using a first stress distribution signature generated by reflected light. They can then re-detect or confirm the object's condition based on a second stress distribution signature generated by transmitted light, thereby improving the accuracy of the test results.

Furthermore, by installing a second photoelastic sensor, users can initially detect whether the object under test contains the aforementioned defects using a first stress distribution signature generated by transmitted light. The second stress distribution signature generated by reflected light can then be used to re-detect or confirm the condition of the object under test, thereby improving the accuracy of the test results.

The contents disclosed above are merely preferred feasible embodiments of the present invention and do not limit the scope of the patent application of the present invention. Therefore, any equivalent technical variations made by applying the contents of the description and drawings of the present invention are included in the scope of the patent application of the present invention.

100: Defect detection method based on photoelasticity

S10-S15: Steps

Claims (8)

A photoelasticity-based defect detection method comprises: Placing an object to be tested on a base; Providing a laser device comprising a collimator, a polarizer, and a laser light source, the laser device being located on a first side of the object to be tested and emitting a first laser beam toward a detection portion of the object to be tested; Providing a first photoelasticity sensor, the first photoelasticity sensor receiving a first reflected light reflected by the first laser beam from the detection portion of the object to be tested to generate a first reflected light signal, or receiving a first transmitted light transmitted by the first laser beam through the detection portion of the object to generate a first transmitted light signal; Providing an imaging device electrically connected to the first photoelasticity sensor, the imaging device receiving the first reflected light signal or the first transmitted light signal to generate a first stress distribution characteristic map; A laser moving device is provided, connected to the laser device, and configured to move the laser device in a three-dimensional space. A first moving device is provided, connected to the first photoelastic sensor, and configured to move the first photoelastic sensor in the three-dimensional space. The photoelasticity-based defect detection method of claim 1 further includes providing a second photoelastic sensor, the second photoelastic sensor being located on a second side of the object to be tested; the first photoelastic sensor being located on the first side; and when the first photoelastic sensor receives the first reflected light to generate the first reflected light signal, the laser device also emits a second laser beam toward the detection portion of the object to be tested. The second photoelastic sensor receives a second transmitted light of the second laser beam that passes through the portion of the object to be tested to generate a second transmitted light signal. The imaging device receives the second transmitted light signal and generates a second stress distribution characteristic map. The photoelasticity-based defect detection method of claim 1 further includes providing a second photoelastic sensor electrically connected to the imaging device, the second photoelastic sensor being located on the first side of the object to be tested; the first photoelastic sensor being located on a second side of the object to be tested, and when the first photoelastic sensor receives the first transmitted light to generate the first transmitted light signal, the laser device also emits a second laser beam toward the detection portion of the object to be tested, and the second photoelastic sensor receives a second reflected light reflected by the second laser beam from the detection portion of the object to be tested to generate a second reflected light signal, wherein the imaging device receives the second reflected light signal to generate a second stress distribution characteristic map. The photoelasticity-based defect detection method as described in claim 2 or 3 further includes providing a second moving device connected to the second photoelastic sensor, wherein the second moving device is used to move the second photoelastic sensor in a three-dimensional space. A photoelasticity-based defect detection system comprises: A control device; A base supporting an object to be tested; A laser device electrically connected to the control device, the laser device comprising a collimator, a polarizer, and a laser light source, the laser device being positioned on a first side of the object to be tested and emitting a first laser beam toward a detection portion of the object to be tested; A first photoelasticity sensor electrically connected to the control device, the first photoelasticity sensor receiving a first reflected light reflected by the first laser beam from the detection portion of the object to be tested to generate a first reflected light signal, or receiving a first transmitted light transmitted by the first laser beam from the detection portion of the object to be tested to generate a first transmitted light signal; An imaging device electrically connected to the control device and the first photoelastic sensor, the imaging device receiving the first reflected light signal or the first transmitted light signal to generate a first stress distribution characteristic map; A laser moving device electrically connected to the control device and the laser device, the laser moving device being configured to move the laser device in a three-dimensional space; and A first moving device electrically connected to the control device and the first photoelastic sensor, the first moving device being configured to move the first photoelastic sensor in the three-dimensional space. The photoelasticity-based defect detection system of claim 5 further includes a second photoelastic sensor electrically connected to the control device and the imaging device, the second photoelastic sensor being located on a second side of the object to be tested. The first photoelastic sensor is located on the first side, and when the first photoelastic sensor receives the first reflected light to generate the first reflected light signal, the laser device also emits a second laser beam toward the detection portion of the object to be tested. The second photoelastic sensor receives a second transmitted light from the second laser beam that passes through the portion of the object to be tested to generate a second transmitted light signal. The imaging device receives the second transmitted light signal and generates a second stress distribution characteristic map. The photoelasticity-based defect detection system as described in claim 5 further includes a second photoelastic sensor electrically connected to the control device and the imaging device, the second photoelastic sensor being located on the first side of the object to be tested; the first photoelastic sensor being located on a second side of the object to be tested, and when the first photoelastic sensor receives the first transmitted light to generate the first transmitted light signal, the laser device also emits a second laser beam toward the detection portion of the object to be tested, and the second photoelastic sensor receives a second reflected light reflected by the second laser beam from the detection portion of the object to be tested to generate a second reflected light signal, wherein the imaging device receives the second reflected light signal and generates a second stress distribution characteristic map. The photoelasticity-based defect detection system as described in claim 6 or 7 further includes a second moving device electrically connected to the control device and connected to the second photoelastic sensor, wherein the second moving device is used to move the second photoelastic sensor in a three-dimensional space.