Self-adaptive adjustment method for inhibiting PCB electron migration and PCB automatic control system

Abstract

The invention discloses a self-adaptive adjustment method for inhibiting PCB electron migration and a PCB automatic control system, and relates to the field of systems for adjusting electrical variables, and the method comprises the following steps: dynamically adjusting current distribution and converting communication modes according to different conditions and priorities. In the process of dynamically adjusting current distribution, communication mode conversion is carried out by a control strategy which takes current density change monitoring as a main mode and takes temperature change monitoring as an auxiliary mode, so that the problems of hot spots and electron migration caused by current / temperature abnormity are prevented, the reliability and stability of the PCB and electronic equipment thereof can be greatly improved, the maintenance cost and the maintenance frequency are reduced, and the service life of the PCB is prolonged. And the method adapts to variable application environments and load conditions. The method can be applied to intelligent electronic equipment such as intelligent access control, intelligent home, intelligent switches, intelligent locks and the like.

Description

Technical Field

[0001] The invention relates to the field of printed circuits, and in particular to an adaptive adjustment method for suppressing PCB electron migration. Background Art

[0002] Electromigration refers to the phenomenon that metal atoms in metal wires migrate due to the impact of current under high current density. This phenomenon was first discovered by Smooth Studeen in the field of microelectronics in the 1950s. With the continuous increase in current density in integrated circuits and PCB design, the phenomenon of electron migration has become more and more serious, which can cause wire breakage, signal failure and other problems, greatly affecting the reliability and service life of electronic equipment.

[0003] At present, methods such as increasing the wire width and reducing the current density are commonly used in PCB design to mitigate the impact of electromigration. However, these methods have certain limitations in high-density and miniaturized PCB design. For example, increasing the wire width may be limited by space, while reducing the current density may sacrifice the performance of the device. Therefore, it is necessary to provide a new method to effectively prevent the electromigration phenomenon in PCB layout, improve the reliability and life of PCB, and then be used to improve the reliability and life of smart electronic devices such as smart access control, smart home, smart switch, smart lock, etc. Summary of the invention

[0004] The purpose of the present invention is to provide an adaptive adjustment method for suppressing PCB electron migration and a PCB automatic control system, which aims to overcome the above-mentioned problems existing in the prior art.

[0005] To achieve the above object, the present invention provides the following technical solutions: An adaptive adjustment method for suppressing PCB electron migration includes the following steps: Step (1), embedding an adaptive current regulation module in the main circuit path of the PCB and setting a backup circuit path; Step (2), when the master device and the slave device of the PCB exchange data through the first communication mode, the adaptive current regulation module continuously monitors the current density of the main circuit path; if the current density exceeds a preset first threshold value, the adaptive current regulation module dynamically adjusts the current distribution; Step (3): after dynamic adjustment, if the current density does not exceed the first threshold, repeat step (2) to perform the next round of dynamic adjustment of current distribution; if the number of dynamic current adjustments reaches the second threshold and the current density still exceeds the first threshold, execute step (4); Step (4), the autonomous control module automatically switches the main circuit path to the backup circuit path, and at the same time converts the first communication mode into the second communication mode, so that the master device and the slave device of the PCB exchange data through the second communication mode, thereby reducing power loss; until the communication is terminated.

[0006] Furthermore, in the above step (4), before switching the main circuit path to the backup circuit path, the main control module activates the electronic components in the backup path through a small current pulse signal, preheats the backup path, and enables it to enter a stable working state in advance, thereby reducing delays and performance fluctuations during switching.

[0007] Furthermore, the above-mentioned adaptive current regulation module includes a current detection unit, a control unit and an execution unit; in the above-mentioned step (2), the current detection unit is responsible for continuously measuring the current density in the circuit and transmitting the data to the control unit; the control unit analyzes the current data and sends a regulation signal to the execution unit according to a predetermined current regulation strategy; the execution unit adjusts the current distribution in the main circuit path according to the regulation signal, and monitors the change of the current density in the main circuit path at the same time, and feeds back the information to the control unit.

[0008] Furthermore, the first communication mode is IIC communication, and the second communication mode is INT single bus communication.

[0009] Furthermore, the above step (4) specifically includes: Sub-step (4.1), initializing and configuring the single bus data line and the controller, adjusting the transmission rate, and sending a reset pulse to initialize communication; Sub-step (4.2), confirm whether the slave device responds to the reset pulse. If the slave device does not respond to the reset pulse, error processing is performed and the communication is terminated directly; if the slave device responds to the reset pulse, enter sub-step (4.3); Sub-step (4.3), determine whether it is necessary to send a ROM command to select a specific slave device. If not, directly send a function command; if necessary, send a ROM command to select a slave device.

[0010] Furthermore, the above step (4) specifically includes: Sub-step (4.4), performing data reading and writing operations between the master device and the slave device to complete data exchange; Sub-step (4.5), after completing the data read and write operation, the master device sends an end signal to end the communication; Sub-step (4.6), close the INT single bus communication interface to release resources.

[0011] Furthermore, the execution unit adjusts the current distribution in the circuit by changing the resistance and / or voltage.

[0012] Furthermore, the adaptive current regulation module dynamically adjusts the current distribution, specifically including the following steps: S31. Define a cost function C to represent the unevenness of the current distribution. The cost function C is defined as the variance of the current density of all paths: ; The optimization goal is to minimize the cost function C, that is ; in, ; J i is the current density of the ith path, N is the number of paths; Define the constraints as follows: ; ; ; Among them, J max is the first threshold, I total is the total current, I i is the current of the ith path; S32, randomly initialize the current I of each path i , and calculate the initial current density J i ; S33, calculate the cost function C for each current I i The gradient is: ; in, is the current density J i For current I i The derivative of S34. Update the current of each path according to the gradient descent method: ; where η is the learning rate; S35, ensure the updated current I i new Satisfy the constraints; if not, make corrections; S36, repeat steps S33-S35 until the cost function C converges to a minimum value.

[0013] Furthermore, the above-mentioned adaptive current regulation module further includes a temperature detection unit, and a plurality of main circuit paths equipped with the current detection unit are taken as a monitored area, and the monitored area is equipped with a temperature detection unit; The above step (2) further includes: using a temperature detection unit to monitor the temperature change of the monitored area in real time, and feeding back the temperature change to the control unit; The above step (3) also includes: after the current distribution is dynamically adjusted n times, when the current density does not exceed the first threshold, if the temperature change shows an upward trend in a subsequent period of time, executing step (4); otherwise, executing step (2).

[0014] A PCB automatic control system is used to implement any of the above-mentioned adaptive adjustment methods; the PCB automatic control system includes a main control module, an adaptive current adjustment module and a backup circuit path integrated in the PCB, the above-mentioned adaptive current adjustment module is used to dynamically adjust the current distribution according to a predetermined current adjustment strategy when the current density of the main circuit path is greater than a first threshold value; the above-mentioned main control module is used to use the backup current path to allow the master device and the slave device of the PCB to exchange data through a second communication method when the current density is still greater than the first threshold value after the dynamic adjustment of the current distribution.

[0015] Furthermore, the above-mentioned adaptive current regulation module includes a current detection unit, a control unit and an execution unit; the above-mentioned current detection unit is used to continuously measure the current density in the circuit and transmit the data to the control unit, the control unit analyzes the current data and sends a regulation signal to the execution unit according to a predetermined current regulation strategy; the execution unit is used to adjust the current distribution in the main circuit path according to the regulation signal, while monitoring the change of current density in the main circuit path, and feeding back the information to the control unit.

[0016] Compared with the prior art, the present invention has the following beneficial effects: In the present invention, the adaptive current regulation technology effectively addresses the problem of electron migration by real-time monitoring and dynamic adjustment of current distribution, greatly improving the reliability and stability of electronic equipment, thereby reducing the work and costs of product after-sales maintenance, product recalls or factory repairs.

[0017] First, in the method disclosed in the present invention, according to different situations and priorities, by dynamically adjusting the current distribution and converting the communication mode, the hot spots and electron migration problems caused by abnormal current density can be effectively dealt with, which can greatly improve the reliability and stability of PCB and its electronic equipment, reduce maintenance costs and repair frequency, and adapt to changing application environments and load conditions. The present invention can be applied to smart electronic devices such as smart access control, smart home, smart switch, and smart lock.

[0018] Secondly, in the method disclosed in the present invention, in the process of dynamically adjusting the current distribution, a control strategy that mainly monitors the current change and supplemented by monitoring the temperature change is used to convert the communication mode, so as to prevent hot spots and electron migration problems caused by abnormal temperature after the dynamic adjustment of the current distribution, and further improve the reliability and stability of the PCB and its electronic equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1The flowchart of the method for preventing electron migration in PCB layout in the present invention.

[0020] Figure 2 This is a simplified structural block diagram of the PCB in the present invention. DETAILED DESCRIPTION

[0021] The specific implementation of the present invention is described below with reference to the accompanying drawings. In order to fully understand the present invention, many details are described below, but for those skilled in the art, the present invention can be implemented without these details.

[0022] like Figure 1 and Figure 2 As shown, an adaptive adjustment method for suppressing PCB electron migration includes the following steps: Step (1): embed an adaptive current regulation module in the main circuit path of the PCB and set a backup circuit path.

[0023] During the PCB design phase, multi-layer wiring technology is used to set up independent wiring layers for the main circuit path and the backup circuit path, and ensure that the two have a certain degree of isolation in physical position to reduce mutual interference. At the same time, an adaptive current regulation module is integrated at the key nodes of the main circuit path, and the module adopts a miniaturized package to save PCB space.

[0024] Preferably, the backup circuit path is optimized to have similar electrical characteristics to the main circuit path, including parameters such as impedance and inductance, to ensure that the performance of the circuit does not change significantly when switching to the backup path.

[0025] Step (2), when the master device and the slave device of the PCB exchange data through the first communication method, the adaptive current regulation module continuously monitors the current density of the main circuit path; if the current density exceeds a preset first threshold, the adaptive current regulation module dynamically adjusts the current distribution to achieve dynamic adjustment of the current to ensure that the current is within a safe range.

[0026] Step (3): After dynamic adjustment, if the current density does not exceed the first threshold, repeat step (2) to perform the next round of dynamic adjustment of current distribution; if the number of dynamic current adjustments reaches the second threshold and the current density still exceeds the first threshold, execute step (4).

[0027] Specifically, in a specific embodiment, the adaptive current regulation module dynamically adjusts the current distribution, including the following steps: It is defined that there are N main current paths on the PCB circuit, and the current density of each path is J i(i=1,2,…,N), the goal is to adjust the current distribution so that the current density of all paths is as uniform as possible while not exceeding the preset first threshold J max .

[0028] Specific: S31, define a cost function C to represent the unevenness of the current distribution. The cost function C can be defined as the variance of the current density of all paths: ,in, is the average current density over all paths: , J i is the current density of the ith path, and N is the number of paths.

[0029] The optimization goal is to minimize the cost function C, that is: .

[0030] Define the constraints as follows: The current density J of each path i Must be less than or equal to the first threshold J max : ; Total current I total Keep constant: ; Among them, I i is the current of the ith path; The current I of the path i Greater than zero: .

[0031] S32, randomly initialize the current I of each path i , and calculate the initial current density J i ; S33, calculate the cost function C for each current I i The gradient is: , in, is the current density J i For current I i The derivative of can be calculated through a specific circuit model; S34, update the current of each path according to the gradient descent method: ; Where η is the learning rate, which controls the step size; S35, ensure the updated current I i new Satisfy the constraints, if not, make corrections; S36, repeating steps S33-S35 until the cost function C converges to a minimum value. Through the above mathematical model, the control unit can automatically calculate and adjust the current distribution to ensure that the current is more evenly distributed in the PCB circuit, thereby preventing hot spots and electronic migration problems.

[0032] Here is an example: Assume that there are three main current paths on the PCB, with initial currents I1=2A, I2=3A, I3=5A, and a total current I total =10A. Maximum allowable current density J max =10A / mm 2 .

[0033] Initialization: Calculate the initial current density J i (Assume that the cross-sectional area of ​​the path is A1=1mm 2 , A2=1mm 2 , A3=1mm 2 ): .

[0034] The cost function is calculated as follows: .

[0035] Optimization: The current is adjusted by gradient descent method so that J i More uniform, while not exceeding J max .

[0036] Step (4), the main control module automatically switches the main circuit path to the backup circuit path, and at the same time converts the first communication mode into the second communication mode, reducing power, so that the master device and the slave device of the PCB exchange data through the second communication mode, thereby reducing power loss; until the communication is terminated.

[0037] Preferably, before switching the main circuit path to the backup circuit path, the main control module activates the electronic components in the backup path through a small current pulse, preheats the backup path, and allows it to enter a stable working state in advance, thereby reducing delays and performance fluctuations during switching.

[0038] like Figure 1 and Figure 2As shown, in one embodiment, the above-mentioned adaptive current regulation module includes a current detection unit, a control unit and an execution unit. In step (2), the current detection unit is responsible for continuously measuring the current density in the circuit and transmitting the data to the control unit; the control unit analyzes the current data and sends a regulation signal to the execution unit according to a predetermined current regulation strategy; the execution unit adjusts the current distribution in the main circuit path according to the regulation signal, monitors the change of the current density in the main circuit path, and feeds back the information to the control unit.

[0039] The current detection unit includes but is not limited to current sensors. High-precision current sensors, such as Hall effect sensors or current detection amplifiers, are deployed in key main circuit paths (such as important signal lines or data lines). Differential measurement technology is used to monitor the current in the main circuit path in real time, measure the change in current, and then calculate the change in current density based on the change in current and the cross-sectional area of ​​the main circuit path. The sampling frequency of the current sensor can be dynamically adjusted according to the operating frequency of the circuit and the signal change rate to ensure accurate current data.

[0040] In addition, the analog signals collected from the current sensor can be converted into digital signals through an analog-to-digital converter (ADC) so that the control unit can perform digital signal processing. Digital signal processing technology can also be used to filter out noise and improve the accuracy and reliability of measurements. Since the adaptive current regulation module constantly monitors the current density, it can respond quickly even when the circuit operating conditions change. This real-time monitoring ensures the timeliness of the current data and provides a basis for dynamic adjustment.

[0041] The intelligent algorithms embedded in the control unit can automatically calculate and adjust the current distribution based on the real-time current density data to make the current distribution more uniform in the PCB circuit, which helps to prevent hot spots and electron migration problems caused by excessive local current. These algorithms include but are not limited to proportional-integral-derivative (PID) control, fuzzy logic control or model-based predictive control to achieve optimal current regulation.

[0042] Once the control unit determines the required adjustment, the execution unit will respond quickly to adjust the current distribution in the circuit by changing the resistance and / or voltage. The execution unit specifically includes but is not limited to achieving precise control of the current by adjusting the variable resistor, switching the power path, or adjusting the working state of the voltage regulator.

[0043] Of course, the adjusted current density will be monitored again by the current detection unit, and the data will be fed back to the control unit to form a closed-loop control. This closed-loop control ensures the effectiveness of the adjustment measures and makes further adjustments when necessary.

[0044] like Figure 1 and Figure 2 As shown, in one embodiment, the above-mentioned adaptive current regulation module includes a temperature detection unit in addition to the current detection unit, the control unit and the execution unit. When designing the PCB, several main circuit paths equipped with current detection units are used as a monitored area, and the monitored area is equipped with a temperature detection unit. Among them, the temperature detection unit includes but is not limited to a temperature sensor, and the analog signal collected from the temperature sensor can be converted into a digital signal through an analog-to-digital converter (ADC) so that the control unit can perform digital signal processing. On this basis, the method for preventing electronic migration in PCB layout also includes: In step (2), the temperature detection unit monitors the temperature change of the monitored area in real time and feeds back the temperature change to the control unit; In step (3), after n times of dynamic adjustment of current distribution, when the current density does not exceed the first threshold, if the temperature change shows an upward trend within a subsequent period of time (such as 1s-2s), step (4) is executed; otherwise, step (2) is executed. Preferably, if the temperature change rises above a third threshold (such as 0.3°C-0.5°C) within a subsequent period of time (such as 1s-2s), step (4) is executed; otherwise, step (2) is executed.

[0045] like Figure 1 and Figure 2 As shown, in one embodiment, the first communication mode is IIC communication; the second communication mode is INT single bus communication, which has low power consumption. Step (4) specifically includes: Sub-step (4.1), initialization configuration of the single bus data line and the controller, adjustment of the transmission rate, and sending of a reset pulse to initialize communication.

[0046] Sub-step (4.2), confirm whether the slave device responds to the reset pulse. If the slave device does not respond to the reset pulse, error processing is performed and the communication is terminated directly; if the slave device responds to the reset pulse, enter sub-step (4.3).

[0047] Sub-step (4.3), determine whether it is necessary to send a ROM command to select a specific slave device. If not, directly send a function command; if necessary, send a ROM command to select a slave device.

[0048] Sub-step (4.4), performing data reading and writing operations between the master device and the slave device to complete data exchange; Sub-step (4.5), after completing the data read and write operation, the master device sends an end signal to end the communication; Sub-step (4.6), close the INT single bus communication interface to release resources.

[0049] INT single bus communication usually has lower power consumption in low-speed, low-power application scenarios. Converting to low-power INT single bus communication can further prevent hot spots and electronic migration problems.

[0050] like Figure 1 and Figure 2 As shown, the present invention also discloses a PCB automatic control system for implementing the above-mentioned adaptive adjustment method, which can be applied to intelligent electronic devices such as smart access control, smart home, smart switch, smart lock, etc. The PCB automatic control system includes a main control module, an adaptive current adjustment module and a backup circuit path integrated in the PCB, and the above-mentioned method for preventing electron migration in the PCB layout is executed through the main control module, the adaptive current adjustment module and the backup circuit path. Among them, the above-mentioned adaptive current adjustment module is used to dynamically adjust the current distribution according to a predetermined current adjustment strategy when the current density of the main circuit path is greater than the first threshold; the above-mentioned main control module is used to use the backup current path to allow the master device and the slave device of the PCB to exchange data through the second communication method when the current density is still greater than the first threshold after the dynamic adjustment of the current distribution.

[0051] Furthermore, the above-mentioned adaptive current regulation module includes a current detection unit, a control unit and an execution unit; the above-mentioned current detection unit is used to continuously measure the current density in the circuit and transmit the data to the control unit, the control unit analyzes the current data and sends a regulation signal to the execution unit according to a predetermined current regulation strategy; the execution unit is used to adjust the current distribution in the main circuit path according to the regulation signal, while monitoring the change of current density in the main circuit path, and feeding back the information to the control unit.

[0052] The above is only a specific implementation of the present invention, but the design concept of the present invention is not limited thereto. Any non-substantial changes to the present invention using this concept shall be deemed as an infringement of the protection scope of the present invention.

Claims

1. An adaptive adjustment method for suppressing PCB electron migration, characterized in that: The following steps are involved: Step (1), embedding an adaptive current regulation module in the main circuit path of the PCB and setting a backup circuit path; Step (2), when the master device and the slave device of the PCB exchange data through the first communication mode, the adaptive current regulation module continuously monitors the current density of the main circuit path; If the current density exceeds a preset first threshold, the adaptive current regulation module dynamically adjusts the current distribution; Step (3): after dynamic adjustment, if the current density does not exceed the first threshold, repeat step (2) to perform the next round of dynamic adjustment of current distribution; if the number of dynamic current adjustments reaches the second threshold and the current density still exceeds the first threshold, execute step (4); Step (4), the main control module automatically switches the main circuit path to the backup circuit path, and at the same time converts the first communication mode into the second communication mode, so that the master device and the slave device of the PCB exchange data through the second communication mode, thereby reducing power loss; until the communication is terminated.

2. The method for adaptively adjusting PCB electron migration according to claim 1, characterized in that: The adaptive current regulation module comprises a current detection unit, a control unit and an execution unit; in the step (2), the current detection unit is responsible for continuously measuring the current density in the circuit and transmitting the data to the control unit; the control unit analyzes the current data and sends a regulation signal to the execution unit according to a predetermined current regulation strategy; the execution unit adjusts the current distribution in the main circuit path according to the regulation signal, monitors the change of the current density in the main circuit path, and feeds back the information to the control unit.

3. The adaptive adjustment method for suppressing PCB electron migration according to claim 1, characterized in that: In step (4), before switching the main circuit path to the backup circuit path, the main control module activates the electronic components in the backup path through a small current pulse signal, preheats the backup path, and enables it to enter a stable working state in advance, thereby reducing delays and performance fluctuations during switching.

4. The method for adaptively adjusting PCB electron migration according to claim 3, characterized in that: The step (4) specifically includes: Sub-step (4.1), initializing and configuring the single bus data line and the controller, adjusting the transmission rate, and sending a reset pulse to initialize communication; Sub-step (4.2), confirm whether the slave device responds to the reset pulse. If the slave device does not respond to the reset pulse, error processing is performed and the communication is terminated directly; if the slave device responds to the reset pulse, enter sub-step (4.3); Sub-step (4.3), determine whether it is necessary to send a ROM command to select a specific slave device. If not, directly send a function command; if necessary, send a ROM command to select a slave device.

5. The method for adaptively adjusting PCB electron migration according to claim 4, characterized in that: The step (4) specifically further includes: Sub-step (4.4), performing data reading and writing operations between the master device and the slave device to complete data exchange; Sub-step (4.5), after completing the data read and write operation, the master device sends an end signal to end the communication; Sub-step (4.6), close the INT single bus communication interface to release resources.

6. The adaptive adjustment method for suppressing PCB electron migration according to claim 2, characterized in that: The execution unit adjusts the current distribution in the circuit by changing the resistance and / or the voltage.

7. The adaptive adjustment method for suppressing PCB electron migration according to claim 1, characterized in that: The adaptive current regulation module dynamically adjusts the current distribution, specifically including the following steps: S31. Define a cost function C to represent the unevenness of the current distribution. The cost function C is defined as the variance of the current density of all paths: ； The optimization goal is to minimize the cost function C, that is ; in, ; J i is the current density of the ith path, N is the number of paths; Define the constraints as follows: ； ； ； Among them, J max is the first threshold, I total is the total current, I i is the current of the ith path; S32, randomly initialize the current I of each path i , and calculate the initial current density J i ; S33, calculate the cost function C for each current I i The gradient is: ； in, is the current density J i For current I i The derivative of S34. Update the current of each path according to the gradient descent method: ; where η is the learning rate; S35, ensure the updated current I i new If the constraints are met, make corrections; S36, repeat steps S33-S35 until the cost function C converges to a minimum value.

8. The method for adaptively adjusting PCB electron migration suppression according to claim 2, characterized in that: The adaptive current regulation module further includes a temperature detection unit, wherein a plurality of main circuit paths equipped with the current detection unit are used as a monitored area, and the monitored area is equipped with a temperature detection unit; The step (2) further comprises: using a temperature detection unit to monitor the temperature change of the monitored area in real time, and feeding back the temperature change to the control unit; The step (3) further includes: after the current distribution is dynamically adjusted n times, when the current density does not exceed the first threshold, if the temperature change shows an upward trend in a subsequent period of time, executing step (4); otherwise, executing step (2).

9. A PCB automatic control system, characterized in that: Used to implement the adaptive adjustment method as described in any one of claims 1 to 8; the PCB automatic control system includes a main control module integrated in the PCB, an adaptive current adjustment module and a backup circuit path, wherein the adaptive current adjustment module is used to dynamically adjust the current distribution according to a predetermined current adjustment strategy when the current density of the main circuit path is greater than a first threshold; The main control module is used to use the backup current path to allow the master device and the slave device of the PCB to exchange data through the second communication method when the current density is still greater than the first threshold after the current distribution is dynamically adjusted.

10. A PCB automatic control system according to claim 9, characterized in that: The adaptive current regulation module includes a current detection unit, a control unit and an execution unit; the current detection unit is used to continuously measure the current density in the circuit and transmit the data to the control unit, the control unit analyzes the current data and sends a regulation signal to the execution unit according to a predetermined current regulation strategy; the execution unit is used to adjust the current distribution in the main circuit path according to the regulation signal, while monitoring the change of current density in the main circuit path, and feeding back the information to the control unit.

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