Image-based substrate electrical property measurement system and method thereof

Abstract

The invention discloses an image-based substrate electrical property measurement system and a method thereof. The image-based substrate electrical property measurement system comprises a measurement device and an electrical property analysis device. The measuring device captures and processes a surface image of the substrate to generate line size information of the substrate. The electrical analysis device analyzes the line size information to generate electrical measurement information, and correspondingly establishes substrate electrical distribution information according to the substrate surface image. According to the invention, electrical information such as impedance, resistance and the like of a whole line can be measured, electrical distribution information of the substrate can be generated according to the surface image of the substrate, the electrical distribution state of the substrate is obtained from the image in a visual mode, and the electrical distribution trend of the substrate is analyzed according to the electrical distribution state.

Description

Technical Field

[0001] The present invention relates to a substrate electrical property measurement system and method, and particularly to an image-based substrate electrical property measurement system and method. Background Art

[0002] The impedance of a circuit board encompasses the overall effect of electrical parameters such as resistance, inductance, and capacitance in the signal transmission lines on the circuit board. These factors can directly affect the signal transmission speed, waveform distortion degree, noise generation, and power consumption. Therefore, strict control of the circuit board impedance is crucial for ensuring signal quality.

[0003] In the fields of high-speed data transmission and high-frequency circuit applications, controlling the impedance of a circuit board is particularly critical to ensure that signals can be transmitted with the highest efficiency and signal distortion is minimized. Failure to meet this requirement will result in adverse effects on signal quality and transmission speed.

[0004] Therefore, the process of evaluating the circuit board impedance is to ensure that the design of the circuit board meets the specified specifications and can transmit signals accurately. By precisely measuring the circuit board impedance, it can be verified whether the signal transmission lines on the circuit board meet the design requirements, and then determine whether corresponding adjustments and optimizations are needed.

[0005] The impedance of a circuit board refers to the characteristic impedance of the signal transmission lines on the circuit board, and its value is usually expressed in ohms (Ohm, Ω). This impedance reflects the impedance characteristics of electrical signals in the signal transmission lines on the circuit board, and its value is affected by many factors, such as the geometric shape of the transmission lines, dielectric constant, signal frequency, etc.

[0006] Traditional methods for measuring the impedance of circuit board transmission lines mainly rely on time-domain reflection (TDR, Time-Domain Reflection) measurement methods. During the process, probes are used to contact the lines to be measured and output signals to complete the measurement.

[0007] However, this contact method has many defects that need to be improved. First of all, there are many problems inherent in contact electrical testing. For example, signal interference such as static electricity or reflection loss may occur during the contact process. In addition, the size of the probe itself causes contact electrical testing to be only possible in certain specific areas of the circuit board and cannot achieve full-board arbitrary point measurement. As circuit boards or electronic components gradually trend towards greater precision, the contact area limitation of the probe also makes contact electrical measurement methods such as time-domain reflection measurement technology face many limitations. Summary of the Invention

[0008] The main objective of the present invention is to provide an image-based substrate electrical measurement system, including a measurement device and an electrical analysis device. The measurement device captures and processes the surface image of the substrate to generate line dimension information of the substrate. The electrical analysis device analyzes the line dimension information to generate electrical measurement information, and correspondingly establishes substrate electrical distribution information based on the surface image of the substrate.

[0009] Optionally, the electrical measurement information includes a line impedance information and / or a line resistance information.

[0010] Optionally, the electrical analysis device generates line impedance information based on line width, line height, dielectric layer height, and dielectric constant.

[0011] Optionally, the electrical analysis device generates line resistance information based on line cross-sectional area and line length.

[0012] Optionally, the substrate electrical distribution information includes substrate impedance / resistance distribution information and substrate impedance / resistance abnormal distribution information.

[0013] Optionally, the electrical analysis device compares the electrical measurement information with the expected electrical information at the corresponding position to obtain error value information, and generates all abnormal distribution conditions on the surface image based on the error value information to establish substrate impedance / resistance abnormal distribution information.

[0014] Optionally, the electrical analysis device generates the distribution of electrical measurement information of all measurement targets on the surface image based on a measurement target on the surface image to establish substrate impedance / resistance distribution information.

[0015] Optionally, the electrical analysis device obtains a process capability index based on the maximum value, minimum value, and average value of the electrical measurement information of all measurement targets, and combines the expected electrical information of the measurement targets.

[0016] Optionally, the substrate electrical distribution information is displayed in the form of a heat map or a grayscale map to present the intensity distribution of the electrical information of the substrate.

[0017] Optionally, the line dimension information includes line width, line height, line pitch, line length, line cross-sectional area, line volume, or three-dimensional line shape.

[0018] Optionally, the measurement device includes:

[0019] A sensing unit that captures the substrate with an image to obtain a two-dimensional image and a three-dimensional image of the surface image;

[0020] An image measurement module, connected or coupled to the sensing unit, and generates line dimension information according to the two-dimensional image and the three-dimensional image of the surface image.

[0021] Optionally, the measurement unit includes a surface scanning camera or a line scanning camera.

[0022] Optionally, the image measurement module generates a plurality of measurement point information corresponding to the substrate based on the surface image.

[0023] Another object of the present invention is to provide a method for electrically measuring a substrate, including: capturing an image of the substrate to obtain a surface image of the substrate; processing the surface image to generate line dimension information of the substrate; generating electrical measurement information based on the line dimension information; and performing full-board line electrical measurement according to the surface image and the electrical measurement information to generate substrate electrical distribution information.

[0024] Optionally, the electrical measurement information includes line impedance information and / or line resistance information.

[0025] Optionally, the line impedance information is generated based on the line width, line height, dielectric layer height, and dielectric constant.

[0026] Optionally, the line resistance information is generated based on the line cross-sectional area and line length.

[0027] Optionally, the substrate electrical distribution information includes substrate impedance / resistance distribution information and substrate impedance / resistance abnormal distribution information.

[0028] Optionally, by comparing the electrical measurement information with the expected electrical information at the corresponding position, error value information is obtained, and all abnormal distribution situations on the surface image are generated based on the error value information to establish substrate impedance / resistance abnormal distribution information.

[0029] Optionally, taking a measurement target on the surface image as a reference, the distribution of the electrical measurement information of all measurement targets on the surface image is generated to establish substrate impedance / resistance distribution information.

[0030] Optionally, based on the maximum value, minimum value, and average value of the electrical measurement information of all measurement targets, and combined with the expected electrical information of the measurement targets, the process capability index is obtained.

[0031] Optionally, the substrate electrical distribution information is displayed in the form of a heat map or a grayscale map to present the intensity distribution of the electrical information of the substrate.

[0032] Optionally, the line dimension information includes line width, line height, line pitch, line length, line cross-sectional area, line volume, or three-dimensional line shape.

[0033] Therefore, in addition to being able to measure electrical information such as the impedance and resistance of the entire circuit board, the present invention can also generate substrate electrical distribution information based on the substrate surface image, obtain the electrical distribution state of the substrate in a visual manner from the image, and analyze the electrical distribution trend of the substrate from the electrical distribution state. Description of the Drawings

[0034] Figure 1 It is a block diagram of the substrate electrical measurement system in the present invention.

[0035] Figure 2 It is a block diagram of one embodiment of the measurement device in the present invention.

[0036] Figure 3 It is a block diagram of another embodiment of the measurement device in the present invention.

[0037] Figure 4 (a) to (f) are schematic views of the appearances of different circuit types in the present invention.

[0038] Figure 5 It is a cross-sectional view of the substrate circuit in the present invention.

[0039] Figure 6 It is a top view of the substrate circuit in the present invention.

[0040] Figure 7 It is a segmentation diagram of multiple cross-sections of the substrate circuit in the present invention.

[0041] Figure 8 It is a cross-sectional view of the microstrip line circuit on the circuit board in the present invention.

[0042] Figure 9 It is a substrate impedance / resistance distribution information diagram in the present invention.

[0043] Figure 10 It is a substrate impedance / resistance abnormal distribution diagram in the present invention.

[0044] Figure 11 It is an electrical precision distribution diagram in the present invention.

[0045] Figure 12 It is a block diagram of the manual inspection device in the present invention.

[0046] Figure 13 It is a flowchart of the substrate electrical measurement method in the present invention.

[0047] The labels in the figures are as follows:

[0048] 100 Substrate electrical measurement system

[0049] 10 Measurement device

[0050] 11 Sensing unit

[0051] 111 Overhead image capturing device

[0052] 112 Side view image capturing device

[0053] L Optical axis direction

[0054] α Imaging angle

[0055] 12 Image measurement module

[0056] 14 Light source

[0057] 20 Electrical analysis device

[0058] 30 Human-machine operation interface

[0059] 31 Host computer

[0060] 32 Display

[0061] 33 Input device

[0062] 40 Defect marking device

[0063] 41 Processor

[0064] 42 Storage device

[0065] T1 Defect location module

[0066] T2 Image marking module

[0067] W Substrate

[0068] UW Upper width of the line on the substrate

[0069] DW Lower width of the line on the substrate

[0070] H Line thickness

[0071] SW1 Width of the first side sidewall

[0072] SW2 Width of the second side sidewall

[0073] S1 First side line pitch

[0074] S2 Second side line pitch

[0075] LR Path

[0076] SG1 - SGN Section

[0077] L1 - LN Sub - section length

[0078] W Line width

[0079] T Line thickness

[0080] Height of H dielectric layer

[0081] Distribution diagram of I1 line thickness

[0082] Tile Q1

[0083] Tile Q2

[0084] Distribution diagram of abnormal I2 substrate impedance / resistance

[0085] Upper region K1

[0086] Lower region K2

[0087] Marker KA1

[0088] Distribution diagram of I3 electrical accuracy

[0089] Method for electrical quantity measurement of substrate image 200 Detailed implementation manner

[0090] The detailed description and technical content of the present invention will be described below in conjunction with the accompanying drawings. Furthermore, for convenience of illustration, the scale of the drawings in the present invention may not be drawn according to the actual scale and there is an exaggerated situation. These drawings and their scales are not intended to limit the scope of the present invention.

[0091] The various materials and data described in the present invention can be stored in any non-transitory storage device, for example, stored on a local server device or a cloud server device, which is not limited in the present invention; or the various materials and data can be stored in the storage device of an individual device or in the database of a central control system, which is also not limited in the present invention.

[0092] In the present invention, the "module" and its corresponding functions can be executed collaboratively after a single chip or a combination of multiple chips are loaded into the storage device. The number of chips configured is not within the scope of limitation of the present invention. In addition, the chips may be, but are not limited to, a combination of devices such as a processor, a central processing unit (CPU), a microprocessor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a programmable logic device (PLD), etc., which are not limited in the present invention. The "storage device" described in the present invention may be, but is not limited to, a cache memory, a dynamic random access memory (DRAM), a persistent memory, etc., or a combination of devices that can be used for storing and retrieving data, which are not limited in the present invention.

[0093] Please first refer to Figure 1 , which is a block diagram of the substrate electrical measurement system in the present invention. This embodiment discloses a substrate electrical measurement system 100 for measuring the circuits of a substrate W and generating corresponding substrate electrical distribution information based on the measurement results, and analyzing the electrical abnormality trend of the entire board circuits through the substrate electrical distribution information for use as reference materials for improving the manufacturing process of the substrate W, thereby improving the production quality of the substrate W during the manufacturing process. The substrate electrical measurement system 100 mainly includes a measurement device 10 and an electrical analysis device 20 connected or coupled to the measurement device 10.

[0094] The "substrate" described in the present invention may include, for example, but is not limited to, a printed circuit board (PCB), a flexible printed circuit (FPC), a ceramic substrate, a multilayer circuit board, or an integrated circuit board such as a wafer or chip, which is not limited in the present invention. The "circuit" described in the present invention may include, for example, but is not limited to, a metal circuit or an etched circuit on the substrate, which is not limited in the present invention. The substrate in the present invention may be a single board including only a set of circuit features or a composite board composed of multiple substrate sub-regions, and these embodiments are not limited in the present invention. In the embodiment of the composite board, the shape and size of each substrate sub-region may be the same or different. Generally, in a large-scale process, multiple substrate sub-regions are usually integrated on a single board, and the substrate sub-regions are cut in the backend process to obtain multiple independent substrate modules.

[0095] To provide personnel with observation and operation, the substrate electrical measurement system 100 further includes a human-machine operation interface 30 for displaying the surface image of the substrate W or the substrate electrical distribution information for personnel reference. The human-machine operation interface 30 may include a computer device, which includes a host 31, a display 32 connected to the host 31 and displaying the substrate electrical distribution information, and an input device 33 (such as a mouse, a keyboard, etc.) connected to the host 31 for personnel to operate. In addition to allowing personnel to perform visual inspection, the human-machine operation interface 30 also allows personnel to perform appropriate operations, such as further generating various reference images or quantification charts based on the established substrate electrical distribution information, so as to facilitate subsequent use as a basis for correcting and compensating various variables in the substrate manufacturing process. In another embodiment, the human-machine operation interface 30 may also be replaced by an external device connected to the network (such as, but not limited to, a local area network or the Internet, etc.). The external device may include, for example, but is not limited to, a computer, a laptop, a mobile device, a server, or a network attached storage device (NAS), etc. The variations of these embodiments are not limited in the present invention.

[0096] Next, please refer to Figure 2 , which is a block diagram of an embodiment of the measurement device in the present invention. The measurement device 10 is used to capture and process the surface image of the substrate W to generate the circuit size information of the substrate W. The measurement device 10 mainly includes a sensing unit 11 and an image measurement module 12.

[0097] The described sensing unit 11 is used for the image capture substrate W to obtain a two-dimensional image and a three-dimensional image of the surface image. The image measurement module 12 is connected or coupled to the sensing unit 11 and generates line dimension information based on the two-dimensional image and the three-dimensional image of the surface image. Herein, the "three-dimensional image" can be three-dimensional information obtained from two or more sets of two-dimensional images, and these three-dimensional information are used to form a three-dimensional image; or it can be obtained by a three-dimensional image capture device, such as a depth camera (time-of-flight camera) or a binocular camera, etc., which is not limited in the present invention. In an embodiment, three-dimensional information can also be obtained through two types of two-dimensional images, and line dimension information can be generated using this three-dimensional information (such as height), which is not limited in the present invention.

[0098] In an embodiment, a large number of high-precision measurements can be performed on the surface of the substrate W by establishing multiple control points in the image; the "large number of high-precision measurements" refers to a measurement technique, which is characterized by using a large number of control points to improve the overall accuracy and details of the measurement. Specifically, for example, multiple sampling control points can be set, a large number of control points or measurement points can be set, or all points can be set (for all measurement points of the object to be measured, such as the point cloud for constructing a three-dimensional image). The above-mentioned control points refer to multiple points selected on the substrate before the measurement work, and the coordinate positions of the points are determined by a precision measuring instrument; the measurement points are control points with arbitrary measurement data attached.

[0099] The described sensing unit 11 is, for example but not limited to, an area scan camera, a line scan camera, or other devices or equipment providing a shooting function, for shooting the surface image of the entire substrate W. In an embodiment, using a line scan camera is more efficient than an area scan camera and can achieve the effect of high-speed measurement. To enable the sensing unit 11 to capture a clear surface image of the substrate W, the measuring device 10 further includes a light source 14. The light source 14 is, for example but not limited to, a ring light, a dome light, a parallel light, a diffused light, or other types of lights providing a lighting function, for providing appropriate illumination to the substrate W.

[0100] The described image measurement module 12 generates line dimension information mainly based on the two-dimensional and three-dimensional images of the surface image captured by the sensing unit 11. To execute the above program, the image measurement module 12 can have corresponding image processing programs for performing image processing functions. The image processing programs include, for example but not limited to, image pre-processing programs, image segmentation and positioning, defect detection (gradientation, region growing, growth compensation, etc.), machine learning systems, deep learning systems, etc. The described image measurement module 12, including but not limited to, can perform image pre-processing procedures (such as image enhancement, noise removal, contrast enhancement, edge enhancement, feature capture, image compression, image conversion, etc.), and segment or capture the boundaries of the image after the image pre-processing procedure to divide the region of interest (ROI). It should be noted that the surface image described in the present invention is not necessarily a single image, and may also be two or more surface images. Specifically, when the processor loads and executes the program of the image measurement module 12, it analyzes the surface image to generate the first region image features (the upper width and the lower width of the line) and the second region image features (the sidewall width of the line) in the surface image. After the image measurement module 12 obtains the first region image features and the second region image features, it analyzes the first region image features and the second region image features to obtain the line dimension information of the substrate W. In one embodiment, the "line dimension information" described in the present invention may include, for example but not limited to, line width, line height, line pitch, line length, line arc or line cross-sectional area, line volume or three-dimensional line shape.

[0101] The described electrical analysis device 20 is used to analyze the line dimension information to generate electrical measurement information, and correspondingly establish the substrate electrical distribution information based on the substrate surface image. Specifically, the electrical analysis device 20 generates electrical measurement information according to the line dimension information. For example, when the processor loads and executes the program, the electrical analysis device 20 calculates the electrical measurement information of the target line on the substrate according to the above line dimension information, thereby achieving the effect of non-contact electrical measurement by optical means. In one embodiment, the "electrical measurement information" described in the present invention may include, for example but not limited to, electrical information with similar properties such as line resistance information and / or line impedance information, which is not limited in the present invention. In one embodiment, the electrical analysis device 20 generates line impedance information based on the line width, line height, dielectric layer height and dielectric constant, and generates line resistance information based on the line cross-sectional area and line length, which is not limited in the present invention.

[0102] Next, please refer to Figure 3, which is a block diagram of another embodiment of the measurement device in the present invention. The difference between this embodiment and the previous embodiment lies only in one specific implementation of the sensing unit 11. Therefore, the parts with the same content will not be described repeatedly here, and are described in advance.

[0103] The sensing unit 11 includes an overhead image capturing device 111 and one or more side view image capturing devices 112. The overhead image capturing device 111 is disposed on the overhead direction side of the substrate W to obtain an overhead image of the substrate W. One or more side view image capturing devices 112 are disposed on one or more side view direction sides of the substrate W to obtain one or more side view images of the substrate W. The line size information can be obtained from the overhead image of the substrate W and one or more side view images. The above images are collectively referred to as surface images.

[0104] The optical axis direction L of the side view image capturing device 112 has an imaging angle α with the surface of the substrate W, and the imaging angle α is between 0 degrees and 90 degrees. The number of the side view image capturing devices 112 is, for example but not limited to, one or more. Among them, the plurality of side view image capturing devices 112 can have the same or different imaging angles α. The above settings can be designed and implemented according to actual detection requirements.

[0105] Through the configuration of the above optical devices, the overhead image and the side view image of the substrate W can be obtained by the overhead image capturing device 111 and the side view image capturing device 112 respectively. Through the above surface images, the image measurement module 12 can generate the line size information of the substrate W, and further, the electrical analysis device 20 can generate electrical measurement information according to the line size information. The acquisition methods of the line size information and the electrical measurement information will be described in the following paragraphs, and are described in advance here.

[0106] In addition to the above embodiments, in another embodiment, the sensing unit 11 can, for example, include a three-dimensional image capturing device, and generate a three-dimensional image by means of three-dimensional measurement. The three-dimensional image capturing device can obtain the three-dimensional information of the substrate by, for example, chromatic confocal measurement, time-of-flight (TOF), triangulation, stereovision method, etc.

[0107] Next, please refer to Figure 4 , (a) to (f) are schematic external views of different line types in the present invention.

[0108] Taking the embodiment of shooting with a single lens as an example, an overhead image including the substrate W can be obtained through the overhead image capturing device 111. Among them, the partially enlarged overhead image can present, for example but not limited to, a straight line as shown in Figure 4 (a), a straight line as shown inFigure 4 The arc bent between the straight lines shown in (b), such as Figure 4 The round hole shown in (c), such as Figure 4 The rectangular area shown in (d), such as Figure 4 The circular area shown in (e), such as Figure 4 The irregular area shown in (f) or any other form of circuit structure is not limited in the present invention.

[0109] The image measurement module 12 can obtain various circuit dimension information including, but not limited to, line width, line height, line pitch, line length, circuit cross-sectional area, circuit volume or three-dimensional circuit shape, etc. through the surface image of the substrate W; it can also obtain hole information, such as hole diameter, hole depth, hole wall area; or other regular or irregular two-dimensional or three-dimensional surface information; it can also measure the appearance information of the entire substrate in a full range and establish the data information of all two-dimensional or three-dimensional measurement points of the entire substrate.

[0110] The method for obtaining the circuit dimension information will be described in the following paragraphs, and it is stated here in advance.

[0111] Next, please refer to Figures 5 to 6 , which is the cross-sectional schematic diagram and the top view schematic diagram of the substrate circuit in the present invention, and please also refer to Figure 3 .

[0112] The circuit of the substrate W mainly includes the following structural information: the upper width UW of the circuit, the lower width DW of the circuit, the circuit thickness H, the width SW1 of the first side sidewall, and the width SW2 of the second side sidewall.

[0113] The following also takes Figure 3Taking the embodiment of using a dual-lens for shooting (the top-view image capture device 111 and the side-view image capture device 112) as an example, through the above-described optical device configuration, the image measurement module 12 can obtain the upper width UW of the line, the lower width DW of the line, the first side wall width SW1, the second side wall width SW2, and the line thickness H that can be further obtained through trigonometric operations from two sets of surface images (top-view image and side-view image) taken from different orientations, and the cross-sectional area of the line can be obtained through calculation using the above data; wherein when the optical axis direction of the camera is orthogonal to the line side wall area of the line (the side wall projection length of the side wall entering the camera is equal to the actual length of the side wall), the side wall width can be directly obtained through distance and ratio calculation, and the line thickness H can be obtained from the side wall width; when the optical axis direction of the camera is non-orthogonal to the line side wall area of the line, the shooting angle of the camera can be considered for correction to obtain the actual side wall width, and the line thickness H can be obtained from the side wall width, or the line thickness H can be obtained through substitution calculation using the width of the side wall in the top-view direction, the shooting angle, and the side wall projection length taken at the corresponding viewing angle. The present invention does not limit this.

[0114] In one embodiment, the line pitch can be calculated from the top-view image. For example, the pitch between adjacent lines can be calculated from the adjacent boundaries between adjacent lines in the top-view image; the line volume can be calculated from the cross-sectional area of the line and the line length. For example, the path LR of the line (see Figure 6 ) can be calculated from the top-view image, and then the line volume can be calculated from the cross-sectional area of each sampled line and the length of each sampled line; the three-dimensional line shape can be calculated from the cross-sectional area of the line and the line shape. For example, the shape of the path LR of the line (see Figure 6 ) can be calculated from the top-view image, and then the three-dimensional line shape of the line can be further generated from the obtained cross-sectional area of the line, the line length, and its shape.

[0115] The described electrical analysis device 20 generates electrical measurement information based on the line dimension information. The electrical measurement information can be, for example, but not limited to, the line thickness, line resistance information, and / or line impedance information, etc. For the method of obtaining the line resistance information, please also refer to Figure 7 , which is a schematic diagram of the segmentation of multiple cross-sections of the substrate line in the present invention. The electrical analysis device 20 can generate line resistance value information based on the cross-sectional area of the line and the line length. Specifically, the line resistance information can be obtained, for example, through the following equation:

[0116]

[0117] wherein, R is the resistance value, ρ is the resistivity, L is the line length, and A is the cross-sectional area of the line. Please refer to Figure 7Based on the cross-sectional area obtained from the previous line dimension information, the cross-sectional area data of each section SG1 - SGn of the line in the maximum resolution can be obtained. After summing up the resistance values corresponding to the cross-sectional areas of each small section length L1 - LN through the previous equation, the line resistance value information of the entire line can be finally obtained.

[0118] Regarding the method for obtaining the line impedance information, please refer to Figure 8 , which is a schematic cross-sectional view of the microstrip line on the circuit board in the present invention. The electrical analysis device 20 can generate line impedance information based on the line width, line thickness, dielectric layer height, and dielectric constant of the target area. Specifically, the electrical analysis device 20 includes but is not limited to, for example, the following equation can be used to obtain the line impedance value information:

[0119]

[0120] where Z0 is the single-ended impedance value, ε r is the relative dielectric constant, W is the line width, T is the line thickness, and H is the dielectric layer height. The relative dielectric constant ε r is a known value; the line width W and the line thickness T can be obtained through image analysis by the aforementioned image measurement module 12. In one embodiment, when the dielectric layer is not obscured in the line image, the dielectric layer height H can be obtained through image analysis by the aforementioned image measurement module 12; in another embodiment, when the dimensional accuracy of the substrate W is relatively stable, the dielectric layer height H can be preset to a fixed value or obtained during pre-measurement, which is not limited in the present invention.

[0121] In the above embodiments, the shape of the line cross-sectional area is exemplified by a rectangle or a trapezoid, but it can also be any other polygon shape. The shape of the line is not used to limit the present invention, which is described herein in advance. The above formula calculation can also be other calculation methods that can be referenced and comply with relevant standards such as IPC issued by the International Electronics Industries Association, including but not limited to, for example, IPC-2221, IPC-2222, IPC-2223, IPC-2224, IPC-2225, IPC-2226, IPC-2227, etc. In another feasible embodiment, the electrical analysis device 20 can also find the corresponding impedance value through methods such as a Look-up Table, a HashTable, a Search Tree, or a Database Index. In the embodiment of using a look-up table, the values not appearing in the look-up table can be calculated by the K-Nearest Neighbor method or the Insertion Method, which depends on the design requirements and is not limited in the present invention.

[0122] The described electrical analysis device 20 performs electrical measurement of the circuit based on the surface image and circuit size information mentioned above to generate a substrate electrical distribution information map. In an embodiment, the substrate electrical distribution information map is displayed in the form of a heat map or a grayscale map. A heat map is a data visualization technique that displays the absolute quantity of a phenomenon in the form of colors in a two-dimensional space. The color form of the heat map is, for example but not limited to, using rainbow color mapping, colors of different shades, intensities, or hues, or any other way that enables a person to intuitively see the circuit information distribution of the substrate W from the image. The concept of the present invention uses continuous changes in colors or grayscale to present the electrical information of the circuits on the substrate W, including but not limited to, such as circuit impedance and / or circuit resistance, their numerical ranges and / or their abnormal change amounts and distributions. The definition of the selection or reference of individual colors is only for illustration and is not limited in the present invention. According to the difference in the detection target and function, the substrate electrical distribution map of the present invention may include, for example but not limited to, a substrate impedance / resistance distribution map and a substrate impedance / resistance abnormal distribution map.

[0123] The substrate electrical distribution map established by the electrical analysis device 20 in the present invention may include, for example, a substrate impedance / resistance distribution map and a substrate impedance / resistance abnormal distribution map.

[0124] After obtaining the electrical measurement information, the image analysis device 20 can generate the distribution of the electrical measurement information of all measurement targets on the surface image based on the measurement targets (such as circuit thickness, impedance, resistance) on the surface image to establish substrate impedance / resistance distribution information.

[0125] Please first refer to Figure 9 , which is the substrate impedance / resistance distribution information map in the present invention, and please also refer to Figure 1 .

[0126] The following will first explain the circuit thickness distribution map: The described electrical analysis device 20 can present the distribution of all substrate impedance / resistance in the image based on the electrical measurement information to establish substrate impedance / resistance distribution information (as shown in Figure I1).

[0127] Such as Figure 9As shown, based on any standard value (which can be set by the user), when the color approaches red more closely (close to cyan in the diagram, such as tile Q1), it indicates that the substrate impedance / resistance value of the corresponding line segment is higher; while when the color approaches blue more closely (such as tile Q2), it indicates that the substrate impedance / resistance value of the corresponding line segment is lower; the intermediate colors between red and blue are set according to the standard value, that is, the closer it is to cyan-blue, the closer it is to the standard value set by the user. In this way, the line thickness distribution of the overall substrate can be seen. Although blue, red, and their intermediate colors are used as the visual basic colors in this embodiment, the selection of these colors is not used to limit the scope of the present invention. In addition to the resistance and impedance values, the line thickness can also be used as a measurement target.

[0128] In order to establish standard data for substrate impedance and resistance, in one embodiment, before the product goes on the production line, the standard wafer can be sent to the device of the present invention for full-panel line electrical measurement via the measuring device 10, thereby obtaining various line measurement information of the standard wafer first (equivalent to line size information and further electrical measurement information), and storing the obtained line measurement information in the database indexed by the line position (such as coordinates) as the expected electrical information of each line coordinate. When the device enters the production line, the electrical analysis device 20 compares the electrical measurement information with the expected electrical information at the corresponding position to obtain the error value information, and generates all abnormal distribution situations on the surface image based on the error value information to establish a substrate impedance / resistance abnormal distribution map. In one embodiment, the error value information can be indexed by coordinates, and it is judged whether there is an electrical abnormality problem with the line according to whether the error value information exceeds a reasonable threshold. In one embodiment, the expected electrical information can be, for example but not limited to, the standard wafer image, the original Computer-Aided Manufacturing (CAM) file, or other similar data stored in the database in advance; the standard wafer can be, for example, a master wafer or a good wafer, which is not limited in the present invention. In another embodiment, the expected electrical information can be, for example but not limited to, including line position, standard line size, standard line resistance, standard line impedance, and / or reasonable threshold (Threshold). In one embodiment, the error value information can be expressed not only by the pure difference value, but also by percentage error, step distance, or other ways, which is not limited in the present invention.

[0129] Please also refer to Figure 10 , which is the substrate impedance / resistance abnormal distribution map in the present invention, and please also refer to Figure 1 .

[0130] In one embodiment, the electrical analysis device 20 can compare the electrical measurement information with the expected electrical information at the corresponding position to obtain error value information, and generate all abnormal distribution conditions on the surface image based on the error value information to establish substrate impedance / resistance abnormal distribution information.

[0131] For example, Figure 1 the human-machine operation interface 30 can present the impedance / resistance distribution of the substrate W for personnel to intuitively view the substrate impedance / resistance distribution of the substrate W. In an alternative embodiment, Figure 10 as shown, color marks are indicated on the substrate impedance / resistance abnormal distribution diagram I2 (revealed as red in the figure or can also be represented by gray scale, and its color is not limited in the present invention), so as to highlight the circuit segments or regions recognized as electrically abnormal on the image. When performing a full-board inspection of the substrate W, these color marks can show the overall abnormal distribution of the substrate W, thereby presenting the full-board substrate impedance / resistance abnormal distribution trend.

[0132] It can be seen from the substrate impedance / resistance abnormal distribution diagram I2 that the number of abnormal points in the upper region K1 of the substrate W is much larger than that in the lower region K2 of the substrate W, and the abnormal points in the lower region K2 of the substrate W are concentrated in the lower positions. In addition, the change of impedance / resistance can be seen from the distribution of the above abnormal points, so as to facilitate subsequent judgment and adjustment of various variables of the substrate manufacturing process. In an alternative embodiment, the substrate impedance / resistance abnormal distribution diagram I2 can not only present the distribution of electrically abnormal points on the entire substrate W, but also present the distribution of abnormal points in a selected local area to obtain the statistical quantity of the number of abnormal points in the local area of the substrate W. The statistical and quantified results are, for example but not limited to, presented in the form of bar charts, pie charts, histograms or other forms of charts or tables, which are not limited in the present invention.

[0133] In an embodiment of the present invention, Figure 10 as shown, the color marks are used to show the circuits where the error values of resistance or impedance exceed the threshold.

[0134] In one embodiment, the relative error magnitude between the measured electrical measurement information and the expected electrical information can be mapped to a heat map, and the corresponding mapped colors of the heat map are used to color the corresponding circuits to establish a substrate sub-region abnormal distribution diagram.

[0135] For example, the human-machine operation interface 30 (refer to Figure 1 ) can present the substrate sub-region electrical abnormal distribution diagram of a single substrate sub-region of the substrate W for personnel to confirm the abnormal distribution trend of all circuits in a single substrate sub-region of the substrate W. In an alternative embodiment, the human-machine operation interface 30 can, through personnel operation, select the substrate impedance / resistance abnormal distribution diagram I2 (such as Figure 10any substrate sub-region shown in the figure), and after clicking, it will be enlarged and independently display the distribution map of electrical anomalies in the substrate sub-region. Specifically, the error value information is determined based on the difference between the electrical measurement information and the expected electrical information at the corresponding position. Through the heat map display, the error magnitude between the electrical measurement information and the expected electrical information can be represented by colors. For example, when the color approaches blue, it indicates that the error between the electrical measurement information and the expected electrical information of the corresponding line segment is lower; while when the color approaches red, it indicates that the error between the electrical measurement information and the expected electrical information of the corresponding line segment is higher; these errors are mapped to the colors within the blue and red intervals to represent the level of the error degree, and the color is used to display the distribution trend of electrical anomalies in a single substrate sub-region. Based on this, the distribution state of electrical anomalies is detected and the process parameters are adjusted.

[0136] Please also refer to Figure 11 , which is the electrical precision distribution map in the present invention, and please also refer to Figure 1 .

[0137] In an embodiment, the electrical analysis device 20 can generate the distribution of the electrical measurement information of all the lines on the surface image based on the electrical measurement information corresponding to the specific lines on the substrate, so as to establish the electrical precision distribution map.

[0138] For example, through Figure 1 the human-machine operation interface 30 can present the distribution map of the electrical measurement information of the substrate W, so that the personnel can intuitively understand the precision distribution trend of the electrical measurement information of the lines in each area of the substrate W. Specifically, taking the expected electrical information of each line segment as the measurement reference, the relative values of the corresponding line segments at the positions corresponding to the selected line segment on other substrate sub-regions are quantified, and then the differences are presented in colors, thereby analyzing the overall electrical precision distribution trend and gradient of the selected line segment and all the corresponding line segments at all positions on the entire substrate W through the image.

[0139] For example, the area where the color approaches white indicates that the electrical measurement information of the corresponding line segment is closer to the preset electrical measurement information, the area where the color approaches dark green indicates that the electrical measurement information of the corresponding line segment is greater than the preset electrical measurement information, and the area where the color approaches dark blue indicates that the electrical measurement information of the corresponding line segment is less than the preset electrical measurement information. The personnel can intuitively understand the electrical precision distribution trend of all the lines on the entire substrate W at the specific line segment from the different color blocks presented by the electrical precision distribution map I3. In a selected embodiment, Figure 11 the colors in the electrical precision distribution map I3 can be converted into a grayscale image. Since different colors have different brightness levels, the differences in the heat zone distribution can be presented by the different shades of the grayscale, for example, the change trend of the electrical precision can be represented by the change in the depth of the grayscale.

[0140] In a selected embodiment, the image analysis device 20 can obtain the Process Capability Index (CPK) based on the maximum value, minimum value, and average value of the electrical measurement information of all measurement targets, in combination with the expected electrical information of the measurement targets. The process capability index is a statistical indicator used to measure the stability and performance of the production process, mainly used to evaluate whether the production process can stably produce qualified products within the specified specification limits. For example, through the expected electrical information obtained by using the standard wafer as described above, plus the standard deviation (σ) allowed in the process, the upper specification limit (USL) and lower specification limit (LSL) of the selected line segment can be obtained, that is, the maximum and minimum values allowed by the process, and the average value (μ) of the electrical measurement information of the entire substrate W for a specific line segment can be obtained through the electrical accuracy distribution diagram I3. Substituting the above values into the following calculation formula can calculate the process capability index (CPK):

[0141]

[0142] Through the above formula, a dimensionless CPK value can be obtained to evaluate the process capability. When the CPK value is greater than or equal to 1.33, it indicates that the process capability is good. If the CPK value is less than 1.33, it indicates that the process needs to be improved.

[0143] In addition, the present invention can also be used for defect marking of circuits. Please refer to Figure 12 together, which is a block diagram of the human inspection device in the present invention, and please refer to it again Figure 1 .

[0144] The substrate electrical measurement system 100 may further include a defect marking device 40, which is connected or coupled to the human-machine operation interface 30. The defect marking device 40 includes a defect location module T1 and an image marking module T2 that are executed by a processor 41 connected to a storage device 42.

[0145] The detection of the defect location module T1 can be for specific points in the circuit, the entire line segment, or specific sections, or selected line areas, or full-board detection, and this part can be carried out according to actual needs. The defect location module T1 can confirm whether the corresponding line has defects by setting a threshold (when the line resistance data or line impedance data is lower or higher than the reasonable threshold range, for example, ±10% of the expected resistance value or expected impedance value), and store the defect location corresponding to the defect in the storage device 42. The defect location can be the coordinates of all pixels within the connected block range, and can also be stored in the form of anchor point coordinates and pixel ranges, which is not limited in the present invention.

[0146] In a selected embodiment, when the defect location module T1 performs a selected line area or full-board inspection, to avoid excessive computational load, the line size of the substrate W can be set as a threshold, and the parts with abnormal sizes can be found according to the threshold, and then the electrical characteristics of the abnormal parts can be detected. In this way, the computational burden can be reduced. In another selected embodiment, after completing the selected line area or full-board inspection, the target object in the image can be directly set, so that the defect location module T1 starts to obtain the electrical measurement information of the target object based on the known line size information of the substrate W at the position of the target object. This method can reduce the computational burden.

[0147] After the defect location module T1 locates the defect position, the image marking module T2 can color the position of the defect, and set an index based on the defect information (such as line resistance information or line impedance information) and the corresponding colored position, and transmit this data to the human-machine operation interface 30 for human inspection of the defect. In a selected embodiment, the display 32 of the human-machine operation interface 30 (see Figure 1 ) can be used to display the surface image of the substrate W and the original computer-aided manufacturing file corresponding to the selected line to facilitate visual inspection by personnel. And through the colored defect position, when the cursor on the display 32 is moved to it by the input device 33 (such as a mouse), various information of the line segment (such as electrical measurement information or other relevant information, etc.) can be displayed to confirm the defect of the corresponding line. For example, personnel can view the corresponding surface image and the original computer-aided manufacturing file on the display 32 at the same time, and can intuitively identify different line defects.

[0148] Next, please refer to Figure 13 together, which is a schematic flowchart of the substrate electrical measurement method in the present invention. According to the above substrate electrical measurement system 100, the present invention further discloses a substrate electrical measurement method 200, which includes the following steps:

[0149] First, an image captures a substrate to obtain a surface image of the substrate (step S01). In terms of the hardware configuration, please refer to Figure 3 again. Taking the embodiment with a dual-lens as an example, in actual operation, a top-view image capture device 111 can be provided on the top-view direction side of the substrate W to obtain a top-view image of the substrate W, and at least one side-view image capture device 112 can be provided on at least one side-view direction side of the substrate W to obtain at least one side-view image of the substrate W, thereby photographing the substrate W from different directions. The above top-view image and side-view image are collectively referred to as the surface image. In another embodiment, a three-dimensional image capture device can be used to directly obtain a three-dimensional image of the substrate W, which is not limited in the present invention.

[0150] Next, the surface image is processed to generate line dimension information of the substrate (step S02). In the present invention, from the surface images of the substrate W taken from different orientations (top view image and side view image) as described above, line dimension information such as but not limited to line width, line height, line pitch, line length, line cross-sectional area, line volume, or three-dimensional line shape can be measured and obtained. For example, from the top view image and the side view image, the upper width UW of the line, the lower width DW of the line, and the first side wall width SW1 and the first side wall width SW2 on both sides of the line can be obtained. Substituting the above dimensions into the trigonometric operation formula can further obtain the line thickness H (see Figure 5 ), and based on the above dimensions, the line cross-sectional area can be further calculated; and the line pitch between adjacent line boundaries can be measured from the top view image; and the line length L and its shape can be measured and obtained from the top view image, and then the line volume and its three-dimensional line shape can be further calculated from the line cross-sectional area.

[0151] Next, the line dimension information is analyzed to generate electrical measurement information (step S03). The electrical measurement information described in the present invention can be, for example, but not limited to, line thickness, line resistance information, and / or line impedance information, etc., which are not limited in the present invention. In one embodiment, the line resistance information is determined according to the line cross-sectional area and the line length, and the line impedance information can be determined according to the line width, the line height, and the dielectric layer height and the dielectric constant.

[0152] Finally, correspondingly according to the surface image of the substrate, substrate electrical distribution information is established (step S04). In an alternative embodiment, the substrate electrical distribution information includes substrate impedance / resistance distribution information and substrate impedance / resistance abnormal distribution information. Among them, the substrate impedance / resistance abnormal distribution information can be obtained by comparing the electrical measurement information with the expected electrical information at the corresponding position to obtain error value information, and based on the error value information, all abnormal distribution situations on the surface image are generated. By the above steps, a substrate impedance / resistance abnormal distribution information map is established; the substrate impedance / resistance distribution information can be based on a measurement target on the surface image to generate the distribution situation of the electrical measurement information of all measurement targets on the surface image, thereby establishing a substrate impedance / resistance distribution information map.

[0153] The above substrate electrical distribution information can be displayed in the form of a heat map or a grayscale map to present the intensity distribution of the electrical information of the substrate W.

[0154] In an alternative embodiment, after obtaining the electrical measurement information, the process capability index (CPK) can be further obtained according to the maximum value, minimum value, and average value of the electrical measurement information of all measurement targets, in combination with the expected electrical information of the measurement targets. If the process capability index is greater than or equal to 1.33, it indicates that the process capability is good; if the CPK value is less than 1.33, it indicates that the process needs improvement.

[0155] In summary, in addition to being able to measure electrical information such as impedance and resistance of the entire circuit board, the present invention can also generate substrate electrical distribution information based on the substrate surface image, obtain the electrical distribution state of the substrate in a visual manner from the image, and analyze the electrical distribution trend of the substrate from the electrical distribution state.

[0156] The present invention has been described in detail above. The above description is only one preferred embodiment of the present invention, and the scope of implementation of the present invention cannot be limited thereby. That is, all equivalent changes and modifications made according to the scope of the patent application of the present invention should still fall within the scope covered by the patent of the present invention.

Claims

1. An image-based substrate electrical property measurement system, characterized in that: include: a measurement device, capturing and processing a surface image of a substrate to generate line dimension information of the substrate; as well as An electrical property analysis device analyzes the circuit dimension information to generate electrical property measurement information, and correspondingly establishes substrate electrical property distribution information according to the surface image.

2. The substrate electrical property measurement system according to claim 1, characterized in that: The electrical property measurement information includes line impedance information and / or line resistance information.

3. The substrate electrical property measurement system according to claim 2, characterized in that: The electrical property analysis device generates the line impedance information based on line width, line height, dielectric layer height and dielectric layer coefficient.

4. The substrate electrical property measurement system according to claim 2, characterized in that: The electrical property analysis device generates the line resistance information based on the line cross-sectional area and the line length.

5. The substrate electrical property measurement system according to claim 2, wherein: The substrate electrical property distribution information includes substrate impedance / resistance distribution information and substrate impedance / resistance abnormal distribution information.

6. The substrate electrical property measurement system according to claim 5, characterized in that: The electrical property analysis device compares the electrical property measurement information with the expected electrical property information of the corresponding position to obtain error value information, and generates all abnormal distribution conditions on the surface image based on the error value information to establish the substrate impedance / resistance abnormal distribution information.

7. The substrate electrical property measurement system according to claim 5, characterized in that: The electrical property analysis device uses a measurement target on the surface image as a reference to generate the distribution of the electrical property measurement information of all the measurement targets on the surface image to establish the substrate impedance / resistance distribution information.

8. The substrate electrical property measurement system according to claim 7, characterized in that: The electrical property analysis device obtains a process capability index according to the maximum value, the minimum value and the average value of the electrical property measurement information of all the measurement targets and combines the expected electrical property information of the measurement targets.

9. The substrate electrical property measurement system according to claim 1, characterized in that: The electrical property distribution information of the substrate is displayed in the form of a heat map or a grayscale map to present the intensity distribution of the electrical property information of the substrate.

10. The substrate electrical property measurement system according to claim 1, wherein: The line dimension information includes line width, line height, line spacing, line length, line cross-sectional area, line volume or three-dimensional line shape.

11. The substrate electrical property measurement system according to claim 1, wherein: The measuring device comprises: a sensing unit that captures the substrate to obtain a two-dimensional image and a three-dimensional image of the surface image; An image measurement module is connected or coupled to the sensing unit and generates the line size information according to the two-dimensional image and the three-dimensional image of the surface image.

12. The substrate electrical property measurement system according to claim 11, characterized in that: The measuring unit includes an area scanning camera or a line scanning camera.

13. The substrate electrical property measurement system according to claim 11, wherein: The image measurement module generates a plurality of measurement point information corresponding to the substrate according to the surface image.

14. A method for measuring electrical properties of a substrate based on an image, characterized in that: include: image capturing a substrate to obtain a substrate surface image of the substrate; Image processing the surface image to generate line size information of the substrate; Analyzing the circuit dimension information to generate electrical property measurement information; as well as Correspondingly, substrate electrical distribution information is established according to the substrate surface image.

15. The method for measuring electrical properties of a substrate according to claim 14, wherein: The electrical property measurement information includes line impedance information and / or line resistance information.

16. The method for measuring electrical properties of a substrate according to claim 15, wherein: The line impedance information is generated based on line width, line height, dielectric layer height and dielectric layer coefficient.

17. The method for measuring electrical properties of a substrate according to claim 15, wherein: The line resistance information is generated based on the line cross-sectional area and the line length.

18. The method for measuring electrical properties of a substrate according to claim 14, wherein: The substrate electrical property distribution information includes substrate impedance / resistance distribution information and substrate impedance / resistance abnormal distribution information.

19. The method for measuring electrical properties of a substrate according to claim 18, wherein: The electrical property measurement information is compared with the expected electrical property information of the corresponding position to obtain error value information, and all abnormal distribution conditions on the surface image are generated based on the error value information to establish the substrate impedance / resistance abnormal distribution information.

20. The method for measuring electrical properties of a substrate according to claim 18, wherein: Taking a measurement target on the surface image as a reference, the distribution of the electrical property measurement information of all the measurement targets on the surface image is generated to establish the substrate impedance / resistance distribution information.

21. The method for measuring electrical properties of a substrate according to claim 20, wherein: A process capability index is obtained according to the maximum value, the minimum value and the average value of the electrical property measurement information of all the measurement targets and combined with the expected electrical property information of the measurement targets.

22. The method for measuring electrical properties of a substrate according to claim 14, wherein: The electrical property distribution information of the substrate is displayed in the form of a heat map or a grayscale map to present the intensity distribution of the electrical property information of the substrate.

23. The method for measuring electrical properties of a substrate according to claim 14, wherein: The line dimension information includes line width, line height, line spacing, line length, line cross-sectional area, line volume or three-dimensional line shape.

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