A performance detection system and method for a flexible circuit board

Abstract

The present invention relates to the field of flexible circuit board detection technology, and specifically to a performance detection system and method for a flexible circuit board, comprising a deformation performance detection module, a durability performance detection module, an electrical performance detection module, a comprehensive analysis module and a report generation module; the present invention systematically detects and evaluates the flexible circuit board from multiple angles such as anti-bending ability, high temperature adaptability, high humidity adaptability, high frequency vibration adaptability, overall circuit stability performance and local circuit stability performance, thereby improving the reliability and comprehensiveness of the detection means, monitoring the overall anti-bending test of the flexible circuit board through a bending test and an ultrasonic sensor, locating the specific position of microcracks generated in the bending test through a double difference positioning method, not only analyzing and evaluating the deformation performance of the flexible circuit board as a whole, but also locating the weak position; extracting harmonic characteristic values ​​through Fourier transform, thereby improving the data accuracy of the detection system.

Description

Technical Field

[0001] The present invention relates to the technical field of flexible circuit board detection, and in particular to a performance detection system and method for a flexible circuit board. Background Art

[0002] Flexible circuit boards are circuit boards with special properties. They are made of polyimide or polyester film as a substrate and are highly reliable and extremely flexible. They have the characteristics of high wiring density, light weight, thin thickness, and good bendability. Flexible circuit boards are widely used in mobile devices, automotive electronic equipment, industrial control, automation and other fields.

[0003] Flexible circuit board testing technology is an important part of ensuring product quality and reliability. It includes testing of circuit on / off, voltage and current values ​​and fluctuation curves, amplitude, noise, fatigue performance and other parameters. Flexible circuit boards may have defects such as open circuits, short circuits, and line width discrepancies during the production process of processing, loading, and mounting. Therefore, flexible circuit board testing is the key to improving quality. Through strict testing technology, the quality and reliability of flexible circuit boards can be ensured to meet the needs of various application fields.

[0004] However, in practical applications, there are many problems and shortcomings in flexible circuit board detection technology, including the difficulty of detection technology, limitations of detection methods, high detection cost, large detection system operation, and insufficient data interpretability of detection results. Therefore, it is necessary to design a performance detection system and method for flexible circuit boards to overcome the above shortcomings. Summary of the invention

[0005] In order to overcome the problems and shortcomings in the background technology, the embodiments of the present invention provide a performance detection system and method for a flexible circuit board.

[0006] The purpose of the present invention can be achieved through the following technical solutions: a performance detection system for a flexible circuit board, including a deformation performance detection module, a durability performance detection module, an electrical performance detection module, a comprehensive analysis module and a report generation module.

[0007] The deformation performance detection module measures the longitudinal wave velocity V0 of the ultrasonic wave in the flexible circuit board through the sonicator, which is recorded as the initial velocity. The flexible circuit board is bent by the loading device, and the flexible circuit board is repeatedly bent at a preset speed V1 for a preset number of times N1, and the flexible circuit board is repeatedly bent at a preset speed V2 for a preset number of times N2, and then the longitudinal wave velocity V1 of the ultrasonic wave in the flexible circuit board is measured again by the sonicator, which is recorded as the velocity after bending.

[0008] As a preferred embodiment of the present invention, the durability performance detection module takes a number of flexible circuit boards and divides them into a high temperature group, a high humidity group and a vibration group according to a preset ratio k1: k2: k3. The average circuit board areas of the flexible circuit boards in the high temperature group, the high humidity group and the vibration group are obtained, and recorded as S1, S2 and S3 respectively; the flexible circuit board in the high temperature group is placed in an environment with a preset temperature a1 and maintained for a preset time t1; the flexible circuit board in the high humidity group is placed in an environment with a preset air humidity a2 and maintained for a preset time t2; the flexible circuit board in the vibration group is placed in a vibration environment with a preset frequency a3 and a preset amplitude a4 through a vibration device, and maintained for a preset time t3.

[0009] As a preferred method of the present invention, the electrical performance detection module obtains the flexible circuit boards of the high temperature group, the high humidity group and the vibration group, and uses the high current spring microneedle module for connection and conduction tests to obtain the insulation resistances R1, R2 and R3 of the flexible circuit boards of the high temperature group, the high humidity group and the vibration group. The flexible circuit boards of the high temperature group, the high humidity group and the vibration group are placed in an external electric field, and the strength of the external electric field is gradually increased until the insulating material in the flexible circuit board is broken down. The electric field strength at this time is recorded as the dielectric strength, and the dielectric strengths E1, E2 and E3 of the flexible circuit boards of the high temperature group, the high humidity group and the vibration group are obtained through experiments.

[0010] As a preferred embodiment of the present invention, the flexible circuit board is connected to an AC power source, and the current waveform of the flexible circuit board is recorded by an oscilloscope. The fundamental wave amplitude f(1), the third harmonic amplitude f(3), and the fifth harmonic amplitude f(5) are extracted by Fourier transform. The frequency peak areas corresponding to the fundamental wave, the third harmonic, and the fifth harmonic are extracted from the frequency spectrum obtained by Fourier transform and recorded as Sf(1), Sf(3), and Sf(5), respectively. By formula Calculate the overall circuit stability index e5, where β1 and β2 are preset weight factors; , and is the preset harmonic standard amplitude; , and is the preset frequency peak area standard value. The number of test points i is obtained using the formula i=β5 / e5, and i components are selected on the flexible circuit board as local circuit test points.

[0011] As a preferred embodiment of the present invention, a high-speed signal test is performed on the circuit on the flexible circuit board based on a flying probe tester, a test signal is sent to a preset test point i in the flexible circuit board and a response signal of the test point is received, wherein i is the test point number, i=1, 2,…, n; n is the total number of preset test points. The received response signal is amplified and filtered, and the response signal is converted from the time domain to the frequency domain using a fast Fourier transform to obtain a frequency spectrum of the response signal. The frequency peaks in the frequency spectrum of the response signal are numbered according to the number j=1, 2,…, m, wherein m is the total number of frequency peaks. The horizontal coordinate corresponding to the highest point of each frequency peak is obtained and recorded as the peak frequency , obtain the ordinate corresponding to the highest point of each frequency peak, recorded as the peak signal intensity The above high-speed signal test process traverses all preset test points to obtain a set of peak frequencies and peak signal strength .

[0012] As a preferred method of the present invention, the data of the deformation performance detection module, the durability performance detection module and the electrical performance detection module are obtained by comprehensive analysis and calculation, specifically:

[0013] By formula The bending resistance coefficient e1 is calculated, where λ1 is a preset weight factor.

[0014] The location of micro cracks in the flexible circuit board is determined based on the double difference positioning method. Specifically, the coordinates of the geometric centroid of each flexible circuit board are preset as (0, 0, 0), the long side direction of the flexible circuit board is preset as the X axis; the short side direction is the Y axis; the thickness direction is the Z axis, and the inversion model formula is used. Calculate the location (X, Y, Z), time and velocity structure of the crack occurrence, where and It is the difference between the predicted arrival time and the actual arrival time of event n at the station, recorded as the first arrival time residual; is the double difference of event m and event n; and represents the observed arrival time of events m and n at the station; is the position coordinate component where event m occurs, p=1, 2, 3; is the position coordinate component where event n occurs, p=1, 2, 3; and Represent the corrections of the source position disturbances of events m and n, p=1, 2, 3; and are the starting moments of time m and event n respectively; and are the slow disturbances of event m and event n respectively; the crack occurrence position (X, Y, Z) obtained

[0015] By formula The high temperature adaptation index e2, the high humidity adaptation index e3 and the high frequency vibration adaptation index e4 are calculated, wherein α1, α2, α3, α4, α5 and α6 are preset weight factors.

[0016] By formula The local circuit stability index e6 is obtained, where and are the preset frequency peak standard value and peak signal strength standard value, where η and ω are the preset influencing factors.

[0017] The bending resistance coefficient e1, high temperature adaptability index e2, high humidity adaptability index e3, high frequency vibration adaptability index e4, overall circuit stability index e5 and local circuit stability index e6 that exceed their respective thresholds are marked.

[0018] As a preferred embodiment of the present invention, the report generation module displays the values ​​of the bending resistance coefficient e1, high temperature adaptability index e2, high humidity adaptability index e3, high frequency vibration adaptability index e4, overall circuit stability index e5 and local circuit stability index e6, displays the calculation process of the index exceeding the threshold value, and displays the collected parameters to generate a detailed calculation report.

[0019] As a preferred embodiment of the present invention, a method for detecting the performance of a flexible circuit board specifically comprises the following steps:

[0020] Step 1: Collect deformation performance data;

[0021] The longitudinal wave velocity V0 of the ultrasonic wave in the flexible circuit board is measured by the sonicator, recorded as the initial velocity. The flexible circuit board is bent by the loading device, and the flexible circuit board is repeatedly bent at a preset speed V1 for a preset number of times N1, and the flexible circuit board is repeatedly bent at a preset speed V2 for a preset number of times N2, and then the longitudinal wave velocity V1 of the ultrasonic wave in the flexible circuit board is measured again by the sonicator, recorded as the velocity after bending.

[0022] Step 2: Collect durability and electrical performance data;

[0023] Take a number of flexible circuit boards and divide them into a high temperature group, a high humidity group and a vibration group according to a preset ratio k1:k2:k3. Obtain the average circuit board areas of the flexible circuit boards in the high temperature group, the high humidity group and the vibration group, and record them as S1, S2 and S3 respectively; place the flexible circuit board in the high temperature group in an environment with a preset temperature a1 and keep it for a preset time t1; place the flexible circuit board in the high humidity group in an environment with a preset air humidity a2 and keep it for a preset time t2; place the flexible circuit board in the vibration group in a vibration environment with a preset frequency a3 and a preset amplitude a4 through a vibration device and keep it for a preset time t3.

[0024] The electrical performance detection module obtains the flexible circuit boards of the high temperature group, high humidity group and vibration group, and uses the high current spring microneedle module for connection and conduction tests to obtain the insulation resistance R1, R2 and R3 of the flexible circuit boards of the high temperature group, high humidity group and vibration group. The flexible circuit boards of the high temperature group, high humidity group and vibration group are placed in an external electric field, and the strength of the external electric field is gradually increased until the insulating material in the flexible circuit board is broken down. The electric field strength at this time is recorded as the dielectric strength. The dielectric strengths E1, E2 and E3 of the flexible circuit boards of the high temperature group, high humidity group and vibration group are obtained through experiments.

[0025] Connect the flexible printed circuit board to an AC power source, record the current waveform of the flexible printed circuit board with an oscilloscope, extract the fundamental wave amplitude f(1), the third harmonic amplitude f(3), and the fifth harmonic amplitude f(5) through Fourier transform, and extract the frequency peak areas corresponding to the fundamental wave, the third harmonic, and the fifth harmonic from the frequency spectrum obtained by Fourier transform, which are recorded as Sf(1), Sf(3), and Sf(5), respectively. Calculate the overall circuit stability index e5, where β1 and β2 are preset weight factors; , and is the preset harmonic standard amplitude; , and is the preset frequency peak area standard value. The number of test points i is obtained using the formula i=β5 / e5, and i components are selected on the flexible circuit board as local circuit test points.

[0026] Based on the flying probe tester, the circuit on the flexible circuit board is tested by high-speed signals. The test signal is sent to the preset test point i in the flexible circuit board and the response signal of the test point is received, where i is the test point number, i=1, 2,…, n; n is the total number of preset test points. The received response signal is amplified and filtered, and the response signal is converted from the time domain to the frequency domain using the fast Fourier transform to obtain the response signal frequency spectrum. The frequency peaks in the response signal frequency spectrum are numbered according to the number j=1, 2,…, m, where m is the total number of frequency peaks. The horizontal coordinate corresponding to the highest point of each frequency peak is obtained and recorded as the peak frequency , obtain the ordinate corresponding to the highest point of each frequency peak, recorded as the peak signal intensity The above high-speed signal test process traverses all preset test points to obtain a set of peak frequencies and peak signal strength .

[0027] Step 3: Data analysis;

[0028] By formula The bending resistance coefficient e1 is calculated, where λ1 is a preset weight factor.

[0029] The location of micro cracks in the flexible circuit board is determined based on the double difference positioning method. Specifically, the coordinates of the geometric centroid of each flexible circuit board are preset as (0, 0, 0), the long side direction of the flexible circuit board is preset as the X axis; the short side direction is the Y axis; the thickness direction is the Z axis, and the inversion model formula is used. Calculate the location (X, Y, Z), time and velocity structure of the crack occurrence, where and It is the difference between the predicted arrival time and the actual arrival time of event n at the station, recorded as the first arrival time residual; is the double difference between event m and event n; and represents the observed arrival time of events m and n at the station; is the position coordinate component where event m occurs, p=1, 2, 3; is the position coordinate component where event n occurs, p=1, 2, 3; and Represent the corrections of the source position disturbances of events m and n, p=1, 2, 3; and are the starting moments of time m and event n respectively; and are the slow disturbances of event m and event n respectively; the crack occurrence position (X, Y, Z) obtained

[0030] By formula The high temperature adaptation index e2, the high humidity adaptation index e3 and the high frequency vibration adaptation index e4 are calculated, wherein α1, α2, α3, α4, α5 and α6 are preset weight factors.

[0031] By formula The local circuit stability index e6 is obtained, where and are the preset frequency peak standard value and peak signal strength standard value, where η and ω are the preset influencing factors.

[0032] Step 4: Report generation;

[0033] The values ​​of the bending resistance coefficient e1, high temperature adaptability index e2, high humidity adaptability index e3, high frequency vibration adaptability index e4, overall circuit stability index e5 and local circuit stability index e6 are displayed. The calculation process of the index exceeding the threshold value and the collected parameters are displayed to generate a detailed calculation book.

[0034] Compared with the prior art, the present invention has the following beneficial effects:

[0035] 1. The present invention extracts the fundamental wave, the third harmonic and the fifth harmonic in the flexible circuit board through Fourier transform, identifies and extracts the higher harmonics, extracts the characteristic values ​​in the response signal through amplification, filtering and Fourier transform, reduces the interference caused by data noise errors in the detection process, and improves the data accuracy of the detection system;

[0036] 2. The present invention monitors the overall anti-bending test of the flexible circuit board through bending tests and ultrasonic sensors, and locates the specific positions of microcracks generated in the bending test through the double difference positioning method. It not only analyzes and evaluates the deformation performance of the flexible circuit board as a whole, but also locates the weak positions, thereby providing detailed data support for the optimization direction of the flexible circuit board, which is conducive to timely discovering potential safety hazards and ensuring the safety of the flexible circuit board during use.

[0037] 3. The present invention systematically detects and evaluates the flexible circuit board from multiple angles such as bending resistance, high temperature adaptability, high humidity adaptability, high frequency vibration adaptability, overall circuit stability and local circuit stability, thereby improving the reliability and comprehensiveness of the detection means, and providing specific calculation processes and parameters, thereby improving the interpretability of the data, which is conducive to making targeted optimization adjustments to products with unqualified test results. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to facilitate understanding by those skilled in the art, the present invention is further described below with reference to the accompanying drawings:

[0039] Figure 1 is a system block diagram of the present invention;

[0040] Figure 2 It is a schematic diagram of the method flow of the present invention; DETAILED DESCRIPTION

[0041] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0042] See also Figure 1 As shown, a performance detection system for a flexible circuit board includes a deformation performance detection module, a durability performance detection module, an electrical performance detection module, a comprehensive analysis module and a report generation module.

[0043] The deformation performance detection module measures the longitudinal wave velocity V0 of the ultrasonic wave in the flexible circuit board through the sonicator, which is recorded as the initial velocity. The flexible circuit board is bent by the loading device, and the flexible circuit board is repeatedly bent at a preset speed V1 for a preset number of times N1, and the flexible circuit board is repeatedly bent at a preset speed V2 for a preset number of times N2, and then the longitudinal wave velocity V1 of the ultrasonic wave in the flexible circuit board is measured again by the sonicator, which is recorded as the velocity after bending.

[0044] The durability performance detection module takes a number of flexible circuit boards and divides them into a high temperature group, a high humidity group and a vibration group according to a preset ratio k1: k2: k3. The average circuit board area of ​​the flexible circuit boards in the high temperature group, the high humidity group and the vibration group is obtained, and recorded as S1, S2 and S3 respectively; the flexible circuit board in the high temperature group is placed in an environment with a preset temperature a1 and maintained for a preset time t1; the flexible circuit board in the high humidity group is placed in an environment with a preset air humidity a2 and maintained for a preset time t2; the flexible circuit board in the vibration group is placed in a vibration environment with a preset frequency a3 and an amplitude a4 through a vibration device, and maintained for a preset time t3.

[0045] The electrical performance detection module obtains the flexible circuit boards of the high temperature group, high humidity group and vibration group, and uses the high current spring microneedle module for connection and conduction tests to obtain the insulation resistance R1, R2 and R3 of the flexible circuit boards of the high temperature group, high humidity group and vibration group. The flexible circuit boards of the high temperature group, high humidity group and vibration group are placed in an external electric field, and the strength of the external electric field is gradually increased until the insulating material in the flexible circuit board is broken down. The electric field strength at this time is recorded as the dielectric strength. The dielectric strengths E1, E2 and E3 of the flexible circuit boards of the high temperature group, high humidity group and vibration group are obtained through experiments.

[0046] Connect the flexible printed circuit board to an AC power source, record the current waveform of the flexible printed circuit board with an oscilloscope, extract the fundamental wave amplitude f(1), the third harmonic amplitude f(3), and the fifth harmonic amplitude f(5) through Fourier transform, and extract the frequency peak areas corresponding to the fundamental wave, the third harmonic, and the fifth harmonic from the frequency spectrum obtained by Fourier transform, which are recorded as Sf(1), Sf(3), and Sf(5), respectively. Calculate the overall circuit stability index e5, where β1 and β2 are preset weight factors; , and is the preset harmonic standard amplitude; , and is the preset frequency peak area standard value. The number of test points i is obtained using the formula i=β5 / e5, and i components are selected on the flexible circuit board as local circuit test points.

[0047] Based on the flying probe tester, the circuit on the flexible circuit board is tested by high-speed signals. The test signal is sent to the preset test point i in the flexible circuit board and the response signal of the test point is received, where i is the test point number, i=1, 2,…, n; n is the total number of preset test points. The received response signal is amplified and filtered, and the response signal is converted from the time domain to the frequency domain using the fast Fourier transform to obtain the response signal frequency spectrum. The frequency peaks in the response signal frequency spectrum are numbered according to the number j=1, 2,…, m, where m is the total number of frequency peaks. The horizontal coordinate corresponding to the highest point of each frequency peak is obtained and recorded as the peak frequency , obtain the ordinate corresponding to the highest point of each frequency peak, recorded as the peak signal intensity The above high-speed signal test process traverses all preset test points to obtain a set of peak frequencies and peak signal strength .

[0048] Comprehensively analyze the data to obtain the data of the deformation performance detection module, durability performance detection module and electrical performance detection module and carry out analysis and calculation, specifically:

[0049] By formula The bending resistance coefficient e1 is calculated, where λ1 is a preset weight factor.

[0050] Based on the double-difference positioning method, the location of microcracks in the flexible circuit board is determined. The cracks and damage in the flexible circuit board are accompanied by local stress concentration. The sound wave signal emitted by the ultrasonic flaw detection instrument will quickly release energy and generate transient elastic waves when passing through these local stress concentration areas. The generation of each transient elastic wave is recorded as an acoustic emission event, hereinafter referred to as an event. By comparing the actual arrival time difference observed at the same measuring station for the transient elastic waves generated by two adjacent events i and j with the arrival time difference obtained by theoretical calculation, the coordinates of the crack location can be inverted. Specifically, the coordinates of the geometric centroid points of each flexible circuit board are preset to (0, 0, 0), the long side direction of the flexible circuit board is preset to be the X-axis; the short side direction is the Y-axis; the thickness direction is the Z-axis, and the inversion model formula is used. Calculate the location (X, Y, Z), time and velocity structure of the crack occurrence, where and It is the difference between the predicted arrival time and the actual arrival time of event n at the station, recorded as the first arrival time residual; is the double difference of event m and event n; and represents the observed arrival time of events m and n at the station; is the position coordinate component where event m occurs, p=1, 2, 3; is the position coordinate component where event n occurs, p=1, 2, 3; and Represent the corrections of the source position disturbances of events m and n, p=1, 2, 3; and are the starting moments of time m and event n respectively; and are the slow disturbances of event m and event n respectively; the crack occurrence position (X, Y, Z) obtained

[0051] By formula The high temperature adaptation index e2, the high humidity adaptation index e3 and the high frequency vibration adaptation index e4 are calculated, wherein α1, α2, α3, α4, α5 and α6 are preset weight factors.

[0052] By formula The local circuit stability index e6 is obtained, where and are the preset frequency peak standard value and peak signal strength standard value, where η and ω are the preset influencing factors.

[0053] The bending resistance coefficient e1, high temperature adaptability index e2, high humidity adaptability index e3, high frequency vibration adaptability index e4, overall circuit stability index e5 and local circuit stability index e6 that exceed their respective thresholds are marked.

[0054] The report generation module displays the values ​​of the bending resistance coefficient e1, high temperature adaptability index e2, high humidity adaptability index e3, high frequency vibration adaptability index e4, overall circuit stability index e5 and local circuit stability index e6, displays the calculation process of the index exceeding the threshold value, and displays the collected parameters to generate a detailed calculation report.

[0055] See also Figure 2 As shown, a performance detection method for a flexible circuit board specifically includes the following steps:

[0056] Step 1: Collect deformation performance data;

[0057] The longitudinal wave velocity V0 of the ultrasonic wave in the flexible circuit board is measured by the sonicator, recorded as the initial velocity. The flexible circuit board is bent by the loading device, and the flexible circuit board is repeatedly bent for a preset number of times N1 at a preset speed V1, and the flexible circuit board is repeatedly bent for a preset number of times N2 at a preset speed V2, and then the longitudinal wave velocity V1 of the ultrasonic wave in the flexible circuit board is measured again by the sonicator, recorded as the velocity after bending.

[0058] Step 2: Collect durability and electrical performance data;

[0059] Take a number of flexible circuit boards and divide them into a high temperature group, a high humidity group and a vibration group according to a preset ratio k1:k2:k3. Obtain the average circuit board areas of the flexible circuit boards in the high temperature group, the high humidity group and the vibration group, and record them as S1, S2 and S3 respectively; place the flexible circuit board in the high temperature group in an environment with a preset temperature a1 and keep it for a preset time t1; place the flexible circuit board in the high humidity group in an environment with a preset air humidity a2 and keep it for a preset time t2; place the flexible circuit board in the vibration group in a vibration environment with a preset frequency a3 and a preset amplitude a4 through a vibration device and keep it for a preset time t3.

[0060] The electrical performance detection module obtains the flexible circuit boards of the high temperature group, high humidity group and vibration group, and uses the high current spring microneedle module for connection and conduction tests to obtain the insulation resistance R1, R2 and R3 of the flexible circuit boards of the high temperature group, high humidity group and vibration group. The flexible circuit boards of the high temperature group, high humidity group and vibration group are placed in an external electric field, and the strength of the external electric field is gradually increased until the insulating material in the flexible circuit board is broken down. The electric field strength at this time is recorded as the dielectric strength. The dielectric strengths E1, E2 and E3 of the flexible circuit boards of the high temperature group, high humidity group and vibration group are obtained through experiments.

[0061] Connect the flexible printed circuit board to an AC power source, record the current waveform of the flexible printed circuit board with an oscilloscope, extract the fundamental wave amplitude f(1), the third harmonic amplitude f(3), and the fifth harmonic amplitude f(5) through Fourier transform, and extract the frequency peak areas corresponding to the fundamental wave, the third harmonic, and the fifth harmonic from the frequency spectrum obtained by Fourier transform, which are recorded as Sf(1), Sf(3), and Sf(5), respectively. Calculate the overall circuit stability index e5, where β1 and β2 are preset weight factors; , and is the preset harmonic standard amplitude; , and is the preset frequency peak area standard value. The number of test points i is obtained using the formula i=β5 / e5, and i components are selected on the flexible circuit board as local circuit test points.

[0062] Based on the flying probe tester, the circuit on the flexible circuit board is tested by high-speed signals. The test signal is sent to the preset test point i in the flexible circuit board and the response signal of the test point is received, where i is the test point number, i=1, 2,…, n; n is the total number of preset test points. The received response signal is amplified and filtered, and the response signal is converted from the time domain to the frequency domain using the fast Fourier transform to obtain the response signal frequency spectrum. The frequency peaks in the response signal frequency spectrum are numbered according to the number j=1, 2,…, m, where m is the total number of frequency peaks. The horizontal coordinate corresponding to the highest point of each frequency peak is obtained and recorded as the peak frequency , obtain the ordinate corresponding to the highest point of each frequency peak, recorded as the peak signal intensity The above high-speed signal test process traverses all preset test points to obtain a set of peak frequencies and peak signal strength .

[0063] Step 3: Data analysis;

[0064] By formula The bending resistance coefficient e1 is calculated, where λ1 is a preset weight factor.

[0065] The location of micro cracks in the flexible circuit board is determined based on the double difference positioning method. Specifically, the coordinates of the geometric centroid of each flexible circuit board are preset as (0, 0, 0), the long side direction of the flexible circuit board is preset as the X axis; the short side direction is the Y axis; the thickness direction is the Z axis, and the inversion model formula is used. Calculate the location (X, Y, Z), time and velocity structure of the crack occurrence, where and It is the difference between the predicted arrival time and the actual arrival time of event n at the station, recorded as the first arrival time residual; is the double difference of event m and event n; and represents the observed arrival time of events m and n at the station; is the position coordinate component where event m occurs, p=1, 2, 3; is the position coordinate component where event n occurs, p=1, 2, 3; and Represent the corrections of the source position disturbances of events m and n, p=1, 2, 3; and are the starting moments of time m and event n respectively; and are the slow perturbations of event m and event n respectively; the crack occurrence position (X, Y, Z) will be obtained.

[0066] By formula The high temperature adaptation index e2, the high humidity adaptation index e3 and the high frequency vibration adaptation index e4 are calculated, wherein α1, α2, α3, α4, α5 and α6 are preset weight factors.

[0067] By formula The local circuit stability index e6 is obtained, where and are the preset frequency peak standard value and peak signal strength standard value, where η and ω are the preset influencing factors.

[0068] Step 4: Report generation;

[0069] The values ​​of the bending resistance coefficient e1, high temperature adaptability index e2, high humidity adaptability index e3, high frequency vibration adaptability index e4, overall circuit stability index e5 and local circuit stability index e6 are displayed. The calculation process of the index exceeding the threshold value and the collected parameters are displayed to generate a detailed calculation book.

[0070] It should be understood that the terms "include" and "comprising" used in the specification and claims of the present disclosure indicate the presence of described features, integers, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or collections thereof.

[0071] It should also be understood that the terms used in this disclosure are only for the purpose of describing specific embodiments and are not intended to limit the disclosure. As used in this disclosure and claims, the singular forms "a", "an", and "the" are intended to include plural forms unless the context clearly indicates otherwise. It should also be further understood that the term "and / or" used in this disclosure and claims refers to any combination of one or more of the associated listed items and all possible combinations, and includes these combinations;

[0072] The preferred embodiments of the present invention disclosed above are only used to help explain the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to only specific implementation methods. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A performance detection system for a flexible circuit board, comprising an electrical performance detection module and a comprehensive analysis module, characterized in that: The electrical performance detection module uses a large current spring microneedle module to perform a conduction test on the flexible circuit boards of the high temperature group, high humidity group and vibration group to obtain the insulation resistance and dielectric strength of the flexible circuit boards of the high temperature group, high humidity group and vibration group when the materials are broken down; the flexible circuit board is connected to an AC power supply, and the current waveform of the flexible circuit board is recorded by a recorder. The fundamental wave amplitude f(1), the third harmonic amplitude f(3) and the fifth harmonic amplitude f(5) are extracted by Fourier transform. The frequency peak areas corresponding to the fundamental wave, the third harmonic and the fifth harmonic are extracted from the frequency spectrum obtained by Fourier transform, and are recorded as Sf(1), Sf(3) and Sf(5) respectively; the formula is used to calculate the current waveform of the flexible circuit board. Calculate the overall circuit stability index e5, where β1 and β2 are preset weight factors; and is the preset harmonic standard amplitude; and It is the preset frequency peak area standard value; The number of test points i is obtained by using the formula i=β5 / e5, and i components are selected on the flexible circuit board as local circuit test points, where β5 is a preset influencing factor and e5 is an overall circuit stability index; components equal to the number of test points are selected on the flexible circuit board as local circuit test points; The comprehensive analysis module obtains the data of the deformation performance detection module, the durability performance detection module and the electrical performance detection module and performs analysis and calculation. Calculate the anti-bending coefficient e1, where λ1 is a preset weight factor, where V0 is the longitudinal wave velocity V0 of the ultrasonic wave in the flexible circuit board; where V1 is the preset velocity one; V2 is the preset velocity two; N1 is the preset bending number one; N2 is the preset bending number two; Based on the double difference positioning method, the occurrence position of micro cracks in the flexible circuit board is determined. The coordinates of the geometric centroid of each flexible circuit board are preset as (0, 0, 0), the long side direction of the flexible circuit board is preset as the X axis; the short side direction is the Y axis; the thickness direction is the Z axis, and the inversion model formula is used. Calculate the location, time and velocity structure of crack occurrence, where and It is the difference between the predicted arrival time and the actual arrival time of event m and event n at the station, recorded as the first arrival time residual; is the double difference between event m and event n; and represents the observed arrival time of events m and n at the station; is the position coordinate component where event m occurs, p=1, 2, 3; is the position coordinate component where event n occurs; and represent the corrections of the source position disturbances of events m and n respectively; and are the starting times of event m and event n respectively; and are the slow disturbances of event m and event n respectively; By formula Calculate the high temperature adaptation index e2, the high humidity adaptation index e3 and the high frequency vibration adaptation index e4, where α1, α2, α3, α4, α5 and α6 are preset weight factors; By formula The local circuit stability index e6 is obtained, where and are the preset frequency peak standard values ​​and peak signal strength standard values, where η and ω are preset influencing factors; the anti-bending coefficient, high temperature adaptation index, high humidity adaptation index, high frequency vibration adaptation index, overall circuit stability index and local circuit stability index that exceed their respective thresholds are marked.

2. A performance detection system for a flexible circuit board according to claim 1, characterized in that: It also includes a deformation performance detection module, a durability performance detection module and a report generation module; The deformation performance detection module measures the initial longitudinal wave velocity of the ultrasonic wave in the flexible circuit board through the sonicator, which is recorded as the initial velocity; the flexible circuit board is bent through the loading device, the flexible circuit board is repeatedly bent at a preset speed one for a preset number of times, the flexible circuit board is repeatedly bent at a preset speed two for a preset number of times, and then the longitudinal wave velocity of the ultrasonic wave in the flexible circuit board is measured again through the sonicator, which is recorded as the velocity after bending; The durability performance detection module takes a number of flexible circuit boards and divides them into a high temperature group, a high humidity group and a vibration group according to a preset ratio; obtains the average circuit board area of ​​the flexible circuit boards in the high temperature group, the high humidity group and the vibration group respectively; places the flexible circuit boards in the high temperature group in an environment with a preset temperature and keeps them for a preset time of one; places the flexible circuit boards in the high humidity group in an environment with a preset air humidity and keeps them for a preset time of two; places the flexible circuit boards in the vibration group in a vibration environment with a preset frequency and a preset amplitude through a vibration device and keeps them for a preset time of three; The report generation module displays the values ​​of the bending resistance coefficient e1, high temperature adaptability index e2, high humidity adaptability index e3, high frequency vibration adaptability index e4, overall circuit stability index e5 and local circuit stability index e6, displays the calculation process of the index exceeding the threshold value, and displays the collected parameters to generate a detailed calculation report.

3. A method for testing the performance of a flexible circuit board, characterized in that: A performance detection system for a flexible circuit board according to any one of claims 1 to 2 is applied to implement the system, comprising the following steps: Step 1: Collect deformation performance data; The initial longitudinal wave velocity of the ultrasonic wave in the flexible circuit board is measured by the sonicator, which is recorded as the initial velocity; the flexible circuit board is bent by the loading device, the flexible circuit board is repeatedly bent at a preset speed one for a preset number of times, the flexible circuit board is repeatedly bent at a preset speed two for a preset number of times, and then the longitudinal wave velocity of the ultrasonic wave in the flexible circuit board is measured again by the sonicator, which is recorded as the velocity after bending; Step 2: Collect durability and electrical performance data; Take a number of flexible circuit boards and divide them into a high temperature group, a high humidity group and a vibration group according to a preset ratio; obtain the average circuit board areas of the flexible circuit boards in the high temperature group, the high humidity group and the vibration group respectively; place the flexible circuit board in the high temperature group in an environment with a preset temperature and keep it for a preset time of one; place the flexible circuit board in the high humidity group in an environment with a preset air humidity and keep it for a preset time of two; place the flexible circuit board in the vibration group in a vibration environment with a preset frequency and a preset amplitude through a vibration device and keep it for a preset time of three; A high-current spring microneedle module is used to conduct a conduction test on the flexible circuit boards of the high-temperature group, the high-humidity group and the vibration group, and the insulation resistance and dielectric strength of the flexible circuit boards of the high-temperature group, the high-humidity group and the vibration group are obtained; the flexible circuit board is connected to an AC power supply and the current waveform of the flexible circuit board is recorded by an oscilloscope, and the fundamental wave amplitude, the third harmonic amplitude and the fifth harmonic amplitude are extracted by Fourier transform, and the frequency peak area corresponding to the fundamental wave, the third harmonic and the fifth harmonic is extracted; the overall circuit stability index is obtained by calculating the harmonic amplitude and the frequency peak area; the number of test points is obtained by calculating the overall circuit stability index, and components whose number is equal to the number of test points are selected on the flexible circuit board as local circuit test points; Step 3, data analysis; obtain the data of the deformation performance detection module, the durability performance detection module and the electrical performance detection module and carry out analysis and calculation, and obtain the anti-bending coefficient by calculating the initial longitudinal wave velocity, preset speed one, bending number one, preset speed two, bending number two and the speed after bending; determine the occurrence location of microcracks in the flexible circuit board based on the double difference positioning method, and obtain the high temperature adaptation index, high humidity adaptation index and high frequency vibration adaptation index by calculating the preset time, average circuit board area, preset temperature, preset air humidity, preset frequency and amplitude of the high temperature group, high humidity group and vibration group; obtain the local circuit stability index by calculating the frequency peak and peak signal strength; mark the anti-bending coefficient, high temperature adaptation index, high humidity adaptation index, high frequency vibration adaptation index, overall circuit stability index and local circuit stability index that exceed their respective thresholds; Step 4: Report generation; display the values ​​of the bending resistance coefficient, high temperature adaptability index, high humidity adaptability index, high frequency vibration adaptability index, overall circuit stability index and local circuit stability index, display the calculation process of the index exceeding the threshold value, and display the collected parameters to generate a detailed calculation report.

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