TWI807567B - Multifunctional standard calibration piece and detecting method of optical detecting apparatus - Google Patents

Abstract

A multifunctional standard calibration piece includes a carrier and plural defect samples. The carrier has a light test area and a particle test area. The light test area is closer to an edge of the carrier than the particle test area. The defect samples are located on the particle test area of the carrier and are separated from each other.

Description

Multifunctional standard calibration sheet and detection method of optical detection equipment

The present disclosure relates to a multifunctional standard calibration sheet and a detection method of optical detection equipment.

Optical inspection equipment (such as automated optical inspection equipment; AOI) needs to monitor its light source status and system status to ensure proper function. For example, optical inspection equipment can use a light source together with an imaging system (such as a camera) to obtain the surface state of the object under test (such as a wafer chuck), which can be used to detect defects of foreign particles.

Since the light source will have light intensity attenuation after long-term use, it is necessary to monitor the light source intensity. A common monitoring method is to use an object with stable reflectance as a standard film (such as gray card, color brick, reflectance standard film) and use a light source to illuminate and capture images, and judge whether the light source intensity is normal based on the obtained image. In addition, the 3D measurement value of the optical inspection equipment is not only affected by the variation of the system components itself (such as damage to the imaging system), but also affected by the variation of the object to be measured, the environment and other factors. Therefore, a stable standard is required to monitor, such as high-level standard slices and particle (PA) standard slices, and use light sources to illuminate and capture images, and judge whether the imaging system is normal based on the obtained images. However, the traditional standard sheet cannot monitor and calibrate the light source and monitor the 3D measurement values of the system components at the same time. It is difficult to shorten the time of the monitoring process, reduce the cost of the standard sheet sample, and reduce the measurement error during monitoring.

One technical aspect of the present disclosure is a multifunctional standard calibration sheet.

According to some embodiments of the present disclosure, a multifunctional standard calibration sheet includes a carrier and a plurality of defect samples. The carrier has a light source detection area and a particle detection area. The light source detection area is closer to the edge of the carrier than the particle detection area. The defect samples are located on the particle detection zone of the carrier and separated from each other.

In some embodiments, the defect sample includes one portion with the same diameter or a plurality of portions with different diameters.

In some embodiments, the diameters of the flawed samples in the first portion are the same, the diameters of the flawed samples in the second portion are the same, and the diameters of the flawed samples in the first portion are smaller than the diameters of the flawed samples in the second portion.

In some embodiments, the distance between adjacent two of the first part of the flawed samples along the length direction of the particle detection zone is 10 times the diameter of the first part of the flawed sample, and the distance between two adjacent ones of the second part of the flawed samples along the length direction of the particle detection zone is 10 times the diameter of the second part of the flawed sample.

In some embodiments, the distance along the length direction of the particle detection zone between the defect sample of the first part closest to one of the defect samples of the second part and the defect sample of the second part closest to one of the defect samples of the first part is in the range of 9 mm to 11 mm.

In some embodiments, the above-mentioned multifunctional standard calibration sheet further includes colloid. The colloid is configured to immobilize each defect sample on the particle detection area of the carrier.

One technical aspect of the present disclosure is a detection method of an optical detection device.

According to some embodiments of the present disclosure, a detection method of an optical detection device includes placing a multi-functional standard calibration sheet on the platform of the optical detection device, wherein the multi-functional standard calibration sheet has a light source detection area and a particle detection area; using the light source module and the imaging system of the optical detection device to take an image of the light source detection area and the particle detection area to obtain an image, wherein the first part of the image corresponds to the light source detection area, and the second part of the image corresponds to the particle detection area; analyzing the state of the light source module according to the first part of the image; like the state of the system.

In some embodiments, the detection method of the optical detection device further includes correcting the light source module when the state of the light source module is analyzed as abnormal, so that the state of the light source module is analyzed as normal after correction.

In some embodiments, the detection method of the optical detection device further includes generating a report when the status analysis of the imaging system is normal.

In some embodiments, the multifunctional standard calibration sheet is placed on the platform of the optical detection device so that the light source detection area is located between the light source module and the particle detection area.

In the above embodiments of the present disclosure, since the carrier of the multi-functional standard calibration sheet has a light source detection area and a particle detection area, and defect samples with different diameters are located on the particle detection area and separated from each other, an image can be obtained when using the light source module and imaging system of the optical detection device to capture the light source detection area and the particle detection area at once, and the first part of the image corresponds to the light source detection area, and the second part of the image corresponds to the particle detection area. In this way, the state of the light source module can be analyzed according to the first part of the image, and the state of the imaging system can be analyzed according to the second part of the image, so that the monitoring and calibration of the light source module and the monitoring of the 3D measurement value of the imaging system (judging whether the system components are abnormal) can be realized by using a single standard calibration sheet at the same time. The multifunctional standard calibration sheet and the detection method of the optical detection equipment disclosed in this disclosure can effectively shorten the time of the monitoring process, reduce the cost of the standard sheet sample, and reduce the measurement error during monitoring.

The description of the embodiments disclosed below provides many different implementations, or examples, for implementing different features of the provided subject matter. Specific examples of components and arrangements are described below to simplify the present case. Of course, these examples are only examples and are not intended to be limiting. In addition, the present case may repeat element symbols and/or letters in various instances. This repetition is for the purposes of brevity and clarity and does not in itself dictate a relationship between the various implementations and/or configurations discussed.

Spatially relative terms such as "below," "beneath," "lower," "above," "upper," etc. may be used herein for convenience of description to describe the relationship of one element or feature to another as shown in the figures. Spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

FIG. 1 shows a top view of a multifunctional standard calibration sheet 100 according to an embodiment of the present disclosure. FIG. 2 shows an enlarged view of the particle detection region 114 of the carrier 110 in FIG. 1 . Referring to FIG. 1 and FIG. 2 at the same time, the multifunctional standard calibration sheet 100 includes a carrier 110 and a plurality of defective samples 120 . The carrier 110 has a light source detection area 112 and a particle detection area 114 . The light source detection area 112 is closer to the edge 111 of the carrier 110 than the particle detection area 114 . The defect samples 120 are located on the particle detection area 114 of the carrier 110 and are separated from each other, and the diameters of these defect samples 120 may be the same or different.

In this embodiment, the material of the carrier 110 can include ceramics or barium sulfate, and its reflective properties can have a linear relationship with the average gray scale of the image when the intensity of the light source changes (will be described in FIG. 7 ), so as to monitor and correct the intensity of the light source. Due to the material properties of the carrier 110 , a part of its surface can be used as the light source detection area 112 . The shape of the carrier 110 can be a rectangle, a circle or other shapes, depending on the design of the optical inspection equipment (such as AOI) used by the multifunctional standard calibration sheet 100 . In addition, the defective sample 120 may be a solder ball, but not limited thereto.

When monitoring and calibrating the optical inspection equipment, the multifunctional standard calibration sheet 100 can be placed on the wafer chuck (Chuck) of the optical inspection equipment, and then the light source module and imaging system (such as a camera) of the optical inspection equipment can obtain an image when taking an image of the light source inspection area 112 and the particle inspection area 114, and the first part of the image corresponds to the light source inspection area 112, and the second part of the image corresponds to the particle inspection area 114. In this way, the state of the light source module can be analyzed according to the first part of the image, and the state of the imaging system can be analyzed according to the second part of the image, so that the monitoring and calibration of the light source module and the monitoring of the 3D quantity detection value of the imaging system can be performed simultaneously using a single standard calibration sheet.

The flawed sample 120 may include one portion with the same diameter (eg, only the first portion of the flawed sample 122 ) or multiple portions with different diameters (eg, the first portion of the flawed sample 122 and the second portion of the flawed sample 124 ). In this embodiment, the flawed samples 120 include a first portion of flawed samples 122 and a second portion of flawed samples 124, and the first portion of flawed samples 122 both have a diameter d1, and the second portion of flawed samples 124 both have a diameter d2. The diameter d1 of the flawed sample 122 of the first portion is smaller than the diameter d2 of the flawed sample 124 of the second portion. In addition, in this embodiment, the number of the defective samples 122 in the first part and the defective samples 124 in the second part are both five, but this disclosure is not limited thereto.

In this embodiment, the diameter d1 of the defect sample 122 of the first part is in the range of 190 μm to 210 μm, for example 200 μm, and the diameter d2 of the defect sample 124 of the second part is in the range of 580 μm to 620 μm, for example 600 μm. In another embodiment, the diameter d1 can be in the range of 40 μm to 60 μm, and the diameter d2 can be in the range of 90 μm to 110 μm, but it is not limited to the range of the above-mentioned diameters d1 and d2, and there can be various arrangements and combinations, depending on the design requirements. The diameter d1 of the defect sample 122 in the first part is similar to the particle diameter on the wafer chuck of the optical inspection device to be tested, so as to serve as a standard defect sample. The defect sample 124 in the second part has a large diameter d2 and reflects more light, which is beneficial to the sensitivity of detecting the position change of the light source, and can be used as a defect sample for auxiliary judgment.

In addition, the distance P1 between adjacent two of the flawed samples 122 in the first part along the length direction D of the particle detection area 114 is 10 times the diameter of the flawed sample 122 in the first part, and the distance P2 between the two adjacent flawed samples 124 in the second part along the length direction D of the particle detection zone 114 is 10 times the diameter of the flawed sample 124 in the second part. The pitch P1 refers to the distance between corresponding positions of the defective samples 122 of two adjacent first portions, and the aforementioned pitch P2 refers to the distance between corresponding positions of the defective samples 124 of two adjacent second portions. The distance d along the length direction D of the particle detection region 114 between the defect sample 122 of the first part closest to one of the defect samples 124 of the second part and the defect sample 124 of the second part closest to one of the defect samples 122 of the first part is in the range of 9 mm to 11 mm, for example 10 mm. Through the arrangement of the defective sample 120 on the particle detection area 114 , it is possible to prevent the shadow produced by the defective sample 120 from affecting the detection result when the particle detection area 114 is illuminated.

The side view of the defective sample 120 glued on the carrier 110 in FIG. 3 and FIG. 2 . As shown in the figure, the multifunctional standard calibration sheet 100 further includes a colloid 130 . The colloid 130 is configured to fix each defect sample 120 on the particle detection area 114 of the carrier 110 . The glue 130 can be UV glue, thermosetting glue or other curable glue, so as to avoid the use of glue that would affect the detection of defects.

It should be understood that the connection relationship, materials and functions of the components that have been described will not be repeated, and will be described first. In the following description, the detection method of the optical detection equipment and other types of multifunctional standard calibration sheets will be described.

FIG. 4 is a flowchart of a detection method of an optical detection device according to an embodiment of the present disclosure. The detection method of the optical detection device includes the following steps. In step S1, a multifunctional standard calibration sheet is placed on the platform of the optical detection device, wherein the multifunctional standard calibration sheet has a light source detection area and a particle detection area. Then in step S2, use the light source module and imaging system of the optical detection device to take an image of the light source detection area and the particle detection area to obtain an image, wherein the first part of the image corresponds to the light source detection area, and the second part of the image corresponds to the particle detection area. Subsequently, in step S3, the state of the light source module is analyzed according to the first part of the image. In step S4, when the status analysis of the light source module is normal, the status of the imaging system is analyzed according to the second part of the image. The detection method of the optical detection device is not limited to the above steps S1 to S4, for example, other steps may be further included between the two preceding and subsequent steps, and other steps may be further included after step S4.

In the following description, each step of the detection method of the optical detection device will be described in detail.

FIG. 5 shows a top view of the multi-functional standard calibration sheet 100a used in the optical inspection device 200 according to an embodiment of the present disclosure. When using the detection method of the optical detection equipment 200, the multifunctional standard calibration sheet 100a can be placed on the platform (such as a wafer chuck) of the optical detection equipment 200, wherein the multifunctional standard calibration sheet 100a has a light source detection area 112 and a particle detection area 114. In this embodiment, the carrier 110 of the multifunctional standard calibration sheet 100a is circular to simulate the situation of the wafer chuck (Chuck) below it. The multifunctional standard calibration sheet 100 a has four light source detection areas 112 and four particle detection areas 114 , but it is not limited thereto.

Next, the light source module 210 and the image capturing system 220 of the optical detection device 200 can be used to capture an image of the light source detection area 112 and the particle detection area 114 of the multifunctional standard calibration sheet 100a to obtain an image, wherein the first part of the image corresponds to the light source detection area 112, and the second part of the image corresponds to the particle detection area 114. The light source 212 of the light source module 210 is configured to provide light. The imaging system 220 includes a lens configured to capture images. In this embodiment, the number of light source modules 210 is four and is arc-shaped, but this disclosure is not limited thereto. The light source module 210 is located around the multifunctional standard calibration sheet 100a for dark-field detection of particles on wafer chucks. For example, the light source module 210 illuminates the light source detection area 112 of the multifunctional standard calibration sheet 100a with an oblique light less than 30 degrees. In addition, when the multifunctional standard calibration sheet 100a is placed on the platform of the optical detection device 200, the light source detection area 112 can be located between the light source module 210 and the particle detection area 114, because the light source detection area 112 is closer to the edge 111 of the carrier 110 than the particle detection area 114, such a configuration can make the detection result of gray scale average - light source intensity (see FIG. 7 ) more linear.

After the image is captured, the state of the light source module 210 can be analyzed according to the first part of the image. In some embodiments, when the status analysis of the light source module 210 is normal, the status of the imaging system 220 is analyzed according to the second part of the image (eg, the 3D volume detection value thereof). When the status analysis of the imaging system 220 is normal, a report is generated. Subsequently, the multifunctional standard calibration sheet 100 a can be taken out from the optical detection device 200 . However, when the status analysis of the imaging system 220 is abnormal, personnel may be notified for maintenance.

In some implementations, when the state of the light source module 210 is analyzed as abnormal, the light source module 210 is corrected so that the state of the light source module 210 is analyzed as normal after correction. For example, since the status of the light source module 210 is abnormal after analysis, it generally indicates that the light source intensity is relatively weak (for example, due to long-term use). To improve this abnormality, the light source module 210 needs to be corrected, that is, the light source intensity of the light source module 210 is increased. Since the light source intensity is proportional to the driving current, the aforementioned correction can increase the light source intensity by increasing the driving current.

Specifically, the detection method of the multifunctional standard calibration sheet 100a and the optical detection device 200 has the following advantages: 1. The monitoring and calibration of the light source module 210 and the monitoring of the 3D quantity detection value of the particle detection area 114 by the imaging system 220 can be performed simultaneously. 2. Since the above two kinds of monitoring can be carried out simultaneously (one-shot imaging), the time of the monitoring process can be shortened. 3. Since the above two kinds of monitoring use the same multifunctional standard calibration sheet 100a, the cost of sample production can be reduced. 4. Since the above two kinds of monitoring are carried out at the same time, it can avoid the deviation introduced by the components or the environment due to the time difference, and can reduce the measurement error during monitoring.

FIG. 6 shows a top view of a multifunctional standard calibration sheet 100b used in an optical detection device 200a according to another embodiment of the present disclosure. The difference from the embodiment shown in FIG. 5 is that the optical detection device 200 a has a single light source module 210 a, and the multifunctional standard calibration sheet 100 a has a single light source detection area 112 and a single particle detection area 114 . In addition, the light source module 210a is strip-shaped, such as a light bar with a plurality of light sources 212a.

FIG. 7 shows the relationship between grayscale average and light source intensity obtained after the light source module irradiates the light source detection area of the carrier according to an embodiment of the present disclosure. The light source module may include more than one light source, and the characteristics of each light source may be slightly different, so a key region (Region of interest; ROI) is selected for each light source. For example, the line L1 and the line L2 can respectively represent the relationship between the grayscale average of the two light sources 212a in FIG. 6 and the intensity of the light source. If the light source 212a of the line L1 is within the standard range, the light source 212a of the line L2 can be judged to be degraded. Therefore, the intensity of the degraded light source 212a can be corrected from the image obtained from the multifunctional standard calibration sheet 100b in FIG. 6 , for example, by increasing the current.

The foregoing outlines features of several embodiments so that those skilled in the art may better understand aspects of the present disclosure. It should be appreciated by those skilled in the art that they may readily use the present disclosure as a basis for designing or modifying other processes and structures, so as to achieve the same purposes and/or achieve the same advantages as the embodiments described herein. Those skilled in the art should also realize that such equivalent constructions do not depart from the spirit and scope of the present disclosure, and that they can make various changes, substitutions and alterations herein without departing from the spirit and scope of the present disclosure.

100, 100a, 100b: multi-function calibration standard 110: carrier 111: edge 112: Light source detection area 114: Particle detection area 120: Blemish samples 122: Blemish samples from part one 124: Blemish samples from part 2 130: colloid 200,200a: Optical detection equipment 210,210a: Light source module 212, 212a: light source 220: Imaging system D: length direction d: distance d1, d2: diameter P1, P2: Pitch L1, L2: line S1, S2, S3, S4: steps

Aspects of the present disclosure are best understood from the following embodiments when read with the accompanying figures. It is noted that, in accordance with the standard practice in the industry, various features are not drawn to scale. In fact, the dimensions of the various features may be arbitrarily increased or decreased for clarity of discussion. FIG. 1 shows a top view of a multifunctional standard calibration sheet according to an embodiment of the present disclosure. FIG. 2 shows an enlarged view of the particle detection area of the carrier in FIG. 1 . The side view of the defective sample glued to the carrier in Fig. 3 and Fig. 2. FIG. 4 is a flowchart of a detection method of an optical detection device according to an embodiment of the present disclosure. FIG. 5 shows a top view of a multifunctional standard calibration sheet used in an optical inspection device according to an embodiment of the present disclosure. FIG. 6 shows a top view of a multifunctional standard calibration sheet used in an optical inspection device according to another embodiment of the present disclosure. FIG. 7 shows the relationship between grayscale average and light source intensity obtained after the light source module irradiates the light source detection area of the carrier according to an embodiment of the present disclosure.

Domestic deposit information (please note in order of depositor, date, and number) none Overseas storage information (please note in order of storage country, institution, date, and number) none

100: Multi-function Standard Calibration Sheet 110: carrier 111: edge 112: Light source detection area 114: Particle detection area 120: Blemish samples 122: Blemish samples from part one 124: Blemish samples from part 2

Claims (10)

A multifunctional standard calibration sheet includes: a carrier with a light source detection area and a particle detection area, wherein the light source detection area is closer to the edge of the carrier than the particle detection area, and the light source detection area and the particle detection area are arranged for an optical detection device to take an image to analyze the state of the light source module and the imaging system of the optical detection device; and a plurality of defect samples are located on the particle detection area of the carrier and separated from each other. The multifunctional standard calibration sheet as claimed in claim 1, wherein the defective samples include a part with the same diameter or a plurality of parts with different diameters. The multifunctional standard calibration sheet as described in claim 1, wherein the diameters of the defective samples of a first part are the same, the diameters of the defective samples of a second part are the same, and the diameters of the defective samples of the first part are smaller than the diameters of the defective samples of the second part. The multifunctional standard calibration sheet as described in claim 3, wherein the distance between adjacent two of the defective samples in the first part along the length direction of the particle detection area is 10 times the diameter of the defective samples in the first part, and the distance between two adjacent two of the defective samples in the second part along the length direction of the particle detection area is 10 times the diameter of the defective samples in the second part. The multifunctional standard calibration sheet as described in claim 3, wherein the distance between the defective samples of the first part closest to one of the defective samples of the second part and the defective samples of the second part closest to one of the defective samples of the first part along the length direction of the particle detection area is in the range of 9 mm to 11 mm. The multifunctional standard calibration sheet as claimed in claim 1 further includes: a colloid configured to fix each of the defective samples on the particle detection area of the carrier. A detection method for optical detection equipment, comprising: placing a multifunctional standard calibration sheet on a platform of the optical detection equipment, wherein the multifunctional standard calibration sheet has a light source detection area and a particle detection area; using a light source module and an imaging system of the optical detection device to take an image of the light source detection area and the particle detection area to obtain an image, wherein a first part of the image corresponds to the light source detection area, and a second part of the image corresponds to the particle detection area; analyzing the state of the light source module according to the first part of the image; When the status analysis of the group is normal, the status of the imaging system is analyzed according to the second part of the image. The detection method of optical detection equipment as described in Claim 7 further includes: when the state of the light source module is analyzed as abnormal, correcting the light source module so that the state of the light source module is analyzed as normal after correction. The detection method of the optical detection device as described in Claim 7 further includes: when the status analysis of the imaging system is normal, generating a report. The inspection method of optical inspection equipment as claimed in item 7, wherein the multifunctional standard calibration sheet is placed on the platform of the optical inspection equipment so that the light source detection area is located between the light source module and the particle detection area.