PCB substrate deformation detection device and method

Abstract

The present invention relates to the field of PCB substrate deformation detection, and specifically discloses a PCB substrate deformation detection device and method. The deformation detection unit includes a strain gauge and a strain acquisition circuit. The strain gauge is disposed at a location to be detected on the PCB substrate. The strain acquisition circuit is connected to the strain gauge, acquires the strain gauge's deformation, and transmits the acquired deformation information to a data processing unit. The data processing unit determines the deformation state of the PCB substrate based on the deformation information, and issues an alarm and / or restricts system power when the deformation state exceeds a threshold. A power supply unit provides power to the deformation detection unit and the data processing unit when the system is online or offline. The present invention can effectively locate and assess the risk of deformation caused by substrates during assembly, testing, transportation, and other processes. It can also report the location information and risk level of the substrate deformation, and decide whether to restrict power to the server based on the collected risk level to avoid subsequent abnormalities.

Description

Technical Field

[0001] The present invention relates to the field of PCB substrate deformation detection, and in particular to a PCB substrate deformation detection device and method. Background Art

[0002] After the PCB substrate is produced, it may cause PCB deformation due to stress in the subsequent steps of patching, sub-boarding, testing, assembly, transportation, etc. Figure 1 As shown in the figure, the substrate is subjected to stress from below, and the substrate appears "convex". Because the components are soldered to the substrate, when the substrate is deformed, the components will also be subjected to tension. When the tension exceeds the maximum force that the components can withstand, cracks will appear inside or on the surface of the components, causing component failure. At the very least, it will cause machine malfunction, and at worst, it will cause the board to burn, bringing unpredictable hazards.

[0003] To address the problem of PCB substrates' prone to deformation, current production processes typically place a jig or tray beneath the PCB during handling or testing to prevent deformation. However, this approach can only minimize the likelihood of deformation and is completely unavoidable during assembly and transport. Currently, there are no effective measures to detect PCB deformation and determine whether it is within the tolerance range of components during all stages of production, testing, assembly, and transportation. Therefore, there is no effective way to detect PCB deformation. Detecting substrate deformation and preventing component damage through the design of the substrate itself is a challenge that needs to be addressed. Summary of the Invention

[0004] To solve the above problems, the present invention provides a PCB substrate deformation detection device and method, which can effectively locate and determine the risk of deformation caused by the substrate during assembly, testing, transportation, etc., and can report the location information and risk level of the substrate deformation. Based on the collected risk level, it is decided whether to restrict the power supply of the server to avoid subsequent abnormal events.

[0005] In a first aspect, the technical solution of the present invention provides a PCB substrate deformation detection device, comprising a deformation detection unit, a data processing unit, and a power supply unit;

[0006] Deformation detection unit: includes a strain gauge and a strain acquisition circuit. The strain gauge is set at the detection location on the PCB substrate. The strain acquisition circuit is connected to the strain gauge to collect the deformation of the strain gauge and send the collected deformation information to the data processing unit.

[0007] Data processing unit: receives deformation information, determines the deformation state of the PCB substrate based on the deformation information, and issues an alarm and / or restricts system power-on when the deformation state exceeds a threshold;

[0008] Power supply unit: connected to the deformation detection unit and the data processing unit respectively, providing power to the deformation detection unit and the data processing unit when the system is online and offline.

[0009] Furthermore, the strain acquisition circuit includes: a second resistor, a third resistor, a first voltage regulator tube, a first capacitor and an analog-to-digital conversion chip;

[0010] The first end of the second resistor is connected to the power supply voltage, the second end is connected to the negative electrode of the first voltage regulator tube, and the positive electrode of the first voltage regulator tube is grounded; the first capacitor is connected in parallel with the first voltage regulator tube; the first end of the third resistor is connected to the negative electrode of the first voltage regulator tube, and the second end is grounded via the strain gauge; and the second end of the third resistor is connected to the input end of the analog-to-digital conversion chip, and the output end of the analog-to-digital conversion chip is connected to the data processing unit.

[0011] Furthermore, the data processing unit includes an MCU and a BMC;

[0012] The MCU is connected to the BMC and determines whether the system is in place based on the BMC signal; the output end of the analog-to-digital conversion chip is connected to the MCU and BMC respectively;

[0013] When the system is online, the analog-to-digital conversion chip transmits the output deformation information to the BMC. The BMC determines the relationship between the deformation and the alarm threshold. If the deformation exceeds the first-level alarm threshold but is less than the second-level alarm threshold, it uploads a normal alarm message. If the deformation exceeds the second-level alarm threshold, it uploads an emergency alarm message and restricts system power supply.

[0014] When the system is offline, the MCU collects the deformation information output by the analog-to-digital conversion chip. The MCU determines the relationship between the deformation and the alarm threshold. If the deformation exceeds the first-level alarm threshold but is less than the second-level alarm threshold, the MCU stores the normal alarm information and the corresponding deformation information. If the deformation is higher than the second-level alarm threshold, the MCU stores the emergency alarm information and the corresponding deformation information.

[0015] Each time the BMC is powered on, it first collects the storage information of the MCU, and then uploads alarm information and powers on the system based on the stored information.

[0016] Furthermore, the ON pin of the MCU is connected to the GPIO1 pin of the BMC, and a pull-down resistor is connected to the line between the ON pin of the MCU and the GPIO1 pin of the BMC;

[0017] When the system is in place, the GPIO1 pin of the BMC sends a high-level signal, and the ON pin of the MCU receives the high-level signal, judging that the system is in place; when the system is offline, the pull-down resistor clamps the ON pin level of the MCU to a low level, and the MCU judges that the system is offline.

[0018] Furthermore, the RST pin of the MCU is connected to the GPIO0 pin of the BMC. When the internal storage data of the MCU exceeds a threshold, the BMC resets the internal storage data of the MCU.

[0019] Furthermore, the BMC is connected to the CPLD, and the CPLD is connected to the enable terminal of the system power supply VR chip. When the BMC detects an emergency alarm, the CPLD triggers the system power supply VR chip to stop working to limit system power-on.

[0020] Furthermore, the power supply unit includes a battery, a switching circuit, a detection power supply VR chip and a charging circuit;

[0021] The control end of the switching circuit is connected to the MCU, the input end is connected to the battery and system power supply respectively, and the output end supplies power to the MCU and analog-to-digital conversion chip; the MCU outputs a control signal to the switching circuit. When the system is online, the system power supply supplies power to the detection power supply VR chip. When the system is offline, the battery supplies power to the detection power supply VR chip.

[0022] The system power supply is also connected to the battery via a charging line.

[0023] Furthermore, the switching circuit includes a first MOS transistor, a second MOS transistor, a third MOS transistor and a first resistor; wherein the first MOS transistor, the second MOS transistor and the third MOS transistor are all N-channel MOS transistors;

[0024] The output end of the MCU is respectively connected to the gates of the first MOS transistor and the third MOS transistor, the drain of the first MOS transistor is connected to the battery, and the source of the first MOS transistor and the drain of the second MOS transistor are voltage output ends; the source of the second MOS transistor is connected to the system power supply, the gate of the second MOS transistor is connected to the second end of the first resistor, the first end of the first resistor is connected to the power supply voltage, and the second end of the first resistor is connected to the drain of the third MOS transistor, and the source of the third MOS transistor is grounded.

[0025] Furthermore, the PSON pin of the battery is grounded via a switch.

[0026] In a second aspect, the technical solution of the present invention provides a method for detecting deformation of a PCB substrate, comprising the following steps:

[0027] Step 1: Place the strain gauge on the part to be detected on the PCB substrate;

[0028] Step 2: Collect the deformation of the strain gauge;

[0029] Step 3: Determine the deformation state of the PCB substrate based on the strain gauge deformation and issue an alarm when the deformation state exceeds a threshold, including:

[0030] 1) When the system is online, the BMC determines the relationship between the deformation and the alarm threshold. If the deformation exceeds the first-level alarm threshold but is less than the second-level alarm threshold, it uploads a normal alarm message. If the deformation exceeds the second-level alarm threshold, it uploads an emergency alarm message and restricts system power on.

[0031] 2) When the system is offline, the MCU determines the relationship between the deformation and the alarm threshold. If the deformation exceeds the first-level alarm threshold but is less than the second-level alarm threshold, it stores the normal alarm information and the corresponding deformation information. If the deformation exceeds the second-level alarm threshold, it stores the emergency alarm information and the corresponding deformation information.

[0032] 3) Each time the BMC is powered on, it first collects the storage information of the MCU, and then uploads the alarm information and powers on the system based on the stored information.

[0033] The present invention provides a PCB substrate deformation detection device and method, which has the following beneficial effects compared to the prior art: a deformation detection unit, a data processing unit, and a power supply unit are configured, wherein the deformation detection unit detects the deformation amount through a strain gauge, and the data processing unit then determines the deformation state of the PCB substrate based on the deformation amount, and issues an alarm or restricts system power supply, including an alarm when a low threshold is exceeded, an alarm and power supply restriction when a high threshold is exceeded, and the power supply unit supplies power to the device at the same time, and can still supply power when the system is offline, ensuring that the deformation of the substrate can also be detected during the assembly and transportation of the substrate. The present invention can effectively locate and determine the risk of deformation caused by the substrate during assembly, testing, transportation, and other links, and can report the location information and risk level of the substrate deformation. Based on the collected risk level, it is decided whether to restrict the power supply to the server to avoid subsequent abnormalities. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the embodiments of the present application or the technical solutions of the prior art, the following is a brief introduction to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0035] Figure 1 It is a schematic diagram of the deformation structure of the PCB substrate.

[0036] Figure 2 This is a schematic block diagram of the structure of a PCB substrate deformation detection device provided by an embodiment of the present invention.

[0037] Figure 3 The figure is a circuit structure diagram of a specific embodiment of a PCB substrate deformation detection device provided by an embodiment of the present invention.

[0038] Figure 4 This is a schematic diagram of a BMC implementing system power-on restriction in a specific embodiment of a PCB substrate deformation detection device provided by an embodiment of the present invention.

[0039] Figure 5 This is a schematic structural diagram of a power supply unit in a specific embodiment of a PCB substrate deformation detection device provided by an embodiment of the present invention.

[0040] Figure 6 yes Figure 5 Schematic diagram of the switching circuit structure.

[0041] Figure 7 The figure is a flow chart of a PCB substrate deformation detection method provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0042] The following is an explanation of some English terms involved in the present invention.

[0043] VR: Voltage Regulator, voltage inverter.

[0044] CPLD: Complex Programmable Logic Device, complex programmable logic device.

[0045] BMC: Baseboard Management Controller.

[0046] MCU: Microcontroller Unit, microcontroller unit.

[0047] GPIO: General-purpose input / output, general-purpose input and output.

[0048] ADC: analog-to-digital conversion.

[0049] In order to enable those skilled in the art to better understand the present application, the present application is further described in detail below in conjunction with the accompanying drawings and specific embodiments. Obviously, the embodiments described are only a part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without making any creative efforts are within the scope of protection of the present application.

[0050] Figure 2 FIG. 1 is a schematic structural diagram of a PCB substrate deformation detection device provided by an embodiment of the present invention. Figure 2 As shown, the device includes: a deformation detection unit, a data processing unit and a power supply unit.

[0051] Deformation detection unit: includes a strain gauge and a strain acquisition circuit. The strain gauge is set at the detection position on the PCB substrate. The strain acquisition circuit is connected to the strain gauge to collect the deformation of the strain gauge and send the collected deformation information to the data processing unit.

[0052] Data processing unit: receives deformation information, determines the deformation state of the PCB substrate based on the deformation information, and issues an alarm and / or restricts system power-on when the deformation state exceeds a threshold.

[0053] Power supply unit: connected to the deformation detection unit and the data processing unit respectively, providing power to the deformation detection unit and the data processing unit when the system is online and offline.

[0054] The device uses strain gauges to detect the deformation state of the PCB substrate, and the strain acquisition circuit collects the deformation amount. The data processing unit then determines whether the deformation of the PCB substrate exceeds a threshold based on the deformation amount. If the threshold is exceeded, an alarm is issued and / or the system power is restricted. At the same time, the device is powered by a power supply unit. The power supply unit can also power the device when the system is offline. This realizes PCB substrate deformation detection in all links such as assembly, testing, and transportation, and promptly detects deformation anomalies to avoid damage to components. When the deformation amount is large, the system power is promptly cut off to avoid serious faults such as burning the board.

[0055] The operating principle of a strain gauge is that it exhibits different impedances under varying deformations. In this embodiment, a strain acquisition circuit collects information about the impedance changes in the strain gauge to determine the deformation state of the PCB substrate. The strain gauges are placed at the locations to be detected on the PCB substrate. This embodiment does not limit the number or specific locations of detection. Users can place strain gauges at all locations suspected of substrate deformation based on actual needs, expanding the detection range and improving design reliability.

[0056] In order to further understand the present invention, a specific embodiment is provided below to further illustrate the present invention in detail. Figure 3 This is a schematic diagram of the circuit structure of this specific embodiment. Figure 3 The deformation detection unit, data processing unit and power supply unit are described.

[0057] (1) Deformation detection unit

[0058] The deformation detection unit realizes the collection of deformation variables and data conversion, and includes a strain gauge and a strain collection circuit.

[0059] Figure 3 Two strain gauges are shown in the figure, X1 and X2. Under different deformations, the strain gauges will exhibit different impedances. The deformation of each strain gauge is collected by its own strain acquisition circuit.

[0060] Taking X1 as an example, the strain acquisition circuit includes resistors R2 and R3, a voltage regulator diode D1, a capacitor C1, and an analog-to-digital converter chip (ADC). The first end of resistor R2 is connected to the supply voltage, and the second end is connected to the cathode of voltage regulator diode D1. The anode of voltage regulator diode D1 is grounded. Capacitor C1 is connected in parallel with voltage regulator diode D1. The first end of resistor R3 is connected to the cathode of voltage regulator diode D1, and the second end is grounded via strain gauge X1. The second end of resistor R3 is connected to the input of the ADC chip, and the output of the ADC chip is connected to the data processing unit.

[0061] R2 is a pull-up resistor that limits current. D1 is a voltage regulator. VCC, through the action of R2 and D1, forms a stable voltage V1 at the negative terminal of D1. C1 is a filter capacitor that filters out high-frequency interference. After V1 is divided by resistor R3 and strain gauge X1, a voltage V2 is generated between them. V2 varies with the strain gauge impedance, and this voltage flows into the CH1 pin of the ADC chip. V2 = V1 / (R3+X1)*X1, where V1 and R3 are fixed values, and V2 and X2 are variables.

[0062] It should be noted that, in this specific embodiment, the deformation detection unit is provided with an ADC chip, and the detection information of each strain gauge is input to the corresponding pin of the ADC chip. Figure 3 As shown, the ADC chip performs analog-to-digital conversion, converting the voltage values ​​collected by the CH1 and CH2 pins into digital signals and transmitting these digital signals to the data processing unit via the I2C bus. The data processing unit locates the corresponding strain gauge based on the corresponding pin signal of the ADC chip, and then locates the deformation position.

[0063] (2) Data processing unit

[0064] The data processing unit realizes the functions of processing deformation variables, dividing alarm levels and limiting system power-on.

[0065] In this specific embodiment, the data processing unit includes an MCU and a BMC. The MCU is connected to the BMC and determines whether the system is in place based on BMC signals. The output of the ADC chip is connected to the MCU and BMC respectively. In the offline state, the MCU performs deformation data processing, alarm level classification, and data temporary storage. When the system is powered on, the BMC directly performs data processing and alarm level classification, reducing data transmission and conversion.

[0066] Among them, the MCU determines whether the system is in place based on the BMC signal. On the one hand, it controls the reception and processing of the ADC chip output signal, and on the other hand, it controls the power supply switching.

[0067] When the system is offline, the MCU collects the deformation information output by the ADC chip. The MCU determines the relationship between the deformation and the alarm threshold. If the deformation exceeds the first-level alarm threshold but is less than the second-level alarm threshold, the MCU stores the normal alarm information and the corresponding deformation information. If the deformation exceeds the second-level alarm threshold, the MCU stores the emergency alarm information and the corresponding deformation information. Specifically, the ADC chip transmits the collected deformation information to the MCU via the I2C bus. The MCU pre-sets two thresholds: the first-level alarm threshold and the second-level alarm threshold, corresponding to the normal alarm state and the emergency alarm state, respectively. If the collected deformation is less than the first-level alarm threshold or the second-level alarm threshold, the MCU determines that the state is safe and does not need to process the information. When the collected deformation is greater than the alarm threshold and less than the secondary alarm threshold, the MCU determines that the state is a normal alarm state, the substrate deformation exceeds the safety baseline, and the MCU stores this normal alarm state and the corresponding ADC chip CHx information; when the collected deformation is greater than the secondary alarm threshold, the MCU determines that the state is an emergency alarm state, the substrate deformation seriously exceeds the safety baseline, and the MCU stores this emergency alarm state and the corresponding ADC chip CHx information; when the system power is in place, the MCU ON signal receives high-level information from the BMC, and the MCU transmits the internally stored alarm information and location information to the BMC through the I2C bus. At this time, the MCU will no longer collect and process information from the ADC chip, and the BMC will directly collect and process the information.

[0068] When the system is online, the analog-to-digital converter chip transmits the output deformation information to the BMC. The BMC determines the relationship between the deformation and the alarm threshold. If the deformation exceeds the first-level alarm threshold but is less than the second-level alarm threshold, it uploads a normal alarm message. If the deformation exceeds the second-level alarm threshold, it uploads an emergency alarm message and simultaneously restricts system power. When the system power is in place, the BMC can operate normally. The BMC directly collects substrate deformation information collected by the ADC chip via the I2C bus. The BMC internally sets the same two-level alarm threshold as the MCU, corresponding to the two-level alarm status. The data processing method is the same as the MCU. The difference is that when the substrate deformation is determined to trigger the normal alarm state, the BMC uploads this alarm information, triggering server maintenance personnel to collect this information immediately. When the substrate deformation is determined to trigger the emergency alarm state, the BMC simultaneously uploads this information and controls the CPLD to restrict system power.

[0069] To ensure system security, the BMC first collects information stored in the MCU each time it powers on. Based on this information, it uploads alarms and powers on the system. Specifically, the BMC immediately collects the MCU's stored alarm information after each power-on and determines whether to continue powering on the system. If no alarms are present, the system continues powering on. If a common alarm is present, the BMC uploads it and the system continues powering on. If an emergency alarm is present, the BMC uploads it and controls the CPLD to limit system powering on.

[0070] In this specific embodiment, the MCU determines whether the system is in place based on BMC signals, specifically by determining the high and low levels of the pins. The MCU's ON pin is connected to the BMC's GPIO1 pin, and a pull-down resistor R6 is connected to the line between the MCU's ON pin and the BMC's GPIO1 pin. When the system is in place, the system power supply and the BMC are functioning normally. The BMC's GPIO1 pin sends a high-level signal, and the MCU's ON pin receives a high-level signal, indicating that the system is in place. When the system is offline, the BMC is unable to operate, and the pull-down resistor R6 clamps the MCU's ON pin to a low level, causing the MCU to determine that the system is offline.

[0071] In addition, in this specific embodiment, the RST pin of the MCU is connected to the GPIO0 pin of the BMC. When the amount of data stored in the MCU is too large, the BMC can actively reset the internal data of the MCU to avoid the risk of data confusion or data loss caused by overload of the MCU data temporary storage.

[0072] When the BMC determines that there is an emergency alarm, it is necessary to restrict system power-on. Figure 4 This is a schematic diagram of how BMC limits system power-on. The BMC is connected to the CPLD, which is in turn connected to the enable terminal of the system power supply VR chip. When the BMC detects an emergency alarm, the CPLD triggers the system power supply VR chip to stop working to limit system power-on. Specifically, the BMC's GPIO2 pin is connected to the CPLD's GPIO0 pin, and the CPLD's GPIO1 pin is connected to the enable signal EN of the system power supply VR chip. When no emergency alarm occurs, the BMC's GPIO2 pin is low. After receiving the low-level information, the CPLD's GPIO0 pin will not operate the GPIO1 pin, and the power supply VR chip can normally supply power to the load. When an emergency alarm occurs, the BMC controls the GPIO2 pin to send a high-level information. After receiving the high-level information, the CPLD's GPIO0 pin will actively pull down the CPLD's GPIO1 pin level, triggering the enable EN of the system power supply VR chip to be low. The system power supply VR chip will not work and cannot output load power.

[0073] This specific embodiment provides two levels of alarm status: normal alarm and emergency alarm, corresponding to the level of substrate deformation. When a normal alarm occurs, the BMC only uploads the alarm to the system to inform backend maintenance personnel. When an emergency alarm occurs, the BMC not only uploads the alarm to the system but also further restricts the system power supply, preventing the system from powering on and avoiding risks. Furthermore, after an emergency alarm occurs, the BMC controls the CPLD to cut off the enable signal of the power supply chip, preventing the VR chip from properly outputting load power, thus implementing power restriction.

[0074] (3) Power supply unit

[0075] Figure 5 This is a schematic diagram of the power supply unit structure of this specific embodiment, including a battery, switching circuit, detection power supply VR chip, and charging circuit. This enables offline power supply. The purpose of offline power supply is to power the substrate deformation detection and alarm system during assembly and transportation of the substrate, even when the server is unpowered. Because the vast majority of substrate deformation occurs during assembly and transportation, adding an offline power supply system effectively covers all assembly and transportation stages, ensuring the effectiveness and feasibility of the invention.

[0076] The detection power supply (VR) chip is primarily responsible for voltage conversion. Its input power is VCC, which is the battery or system power after passing through the conversion circuit. Its output is VOUT, the power supply required for the ADC and MCU. The VR chip converts VCC to VOUT, providing the ADC and MCU with a voltage level that allows them to operate normally, ensuring stable system operation. C3 and C4 are filter capacitors.

[0077] The control end of the switching circuit is connected to the MCU, the input end is connected to the battery and system power supply respectively, and the output end outputs power to the MCU and analog-to-digital conversion chip; the MCU outputs a control signal to the switching circuit. When the system is online, the system power supply supplies power to the detection power supply VR chip. When the system is offline, the battery supplies power to the detection power supply VR chip; the system power supply is also connected to the battery via a charging circuit.

[0078] The MCU outputs a control signal to the switching circuit according to the detected system on-site and off-line status, controlling the connection switching between the switching circuit input terminal and the battery and system power supply.

[0079] Figure 6 : is a schematic diagram of the switching circuit structure of this specific embodiment, including a first MOS transistor MOSFET1, a second MOS transistor, a third MOS transistor MOSFET3 and a first resistor R1; wherein the first MOS transistor MOSFET1, the second MOS transistor MOSFET2 and the third MOS transistor MOSFET3 are all N-channel MOS transistors.

[0080] The output end of the MCU is respectively connected to the gates of the first MOS transistor MOSFET1 and the third MOS transistor MOSFET3. The drain of the first MOS transistor MOSFET1 is connected to the battery. The source of the first MOS transistor MOSFET1 and the drain of the second MOS transistor MOSFET2 are voltage output ends. The source of the second MOS transistor MOSFET2 is connected to the system power supply. The gate of the second MOS transistor MOSFET2 is connected to the second end of the first resistor R1. The first end of the first resistor R1 is connected to the power supply voltage. At the same time, the second end of the first resistor R1 is connected to the drain of the third MOS transistor MOSFET3. The source of the third MOS transistor MOSFET3 is grounded.

[0081] R1 is a pull-up resistor that acts as a current limiter. The MCU sends a control signal to control the conduction of each MOSFET. When the control signal from the MCU is high, MOSFET1 and MOSFET3 are turned on, and MOSFET2 is turned off. At this time, VCC is provided by the battery power supply. When the control signal from the MCU is low, MOSFET1 and MOSFET3 are turned off, and MOSFET2 is turned on. At this time, VCC is provided by the system power supply.

[0082] Among them, when the system power is in place, the BMC cannot work and is in a low-level state; when the system power is not in place, the BMC cannot work and is in a high-level state.

[0083] The battery's PSON pin determines whether the battery can output power. When the PSON signal is low, the battery can output power normally. When the PSON signal is floating or high, the battery cannot output power. This specific embodiment utilizes this principle by directly connecting a switch SW1 between the battery's PSON and GND pins to enable manual intervention. When SW1 is closed, PSON is grounded, allowing the battery to output power normally. When SW1 is open, PSON is floating, preventing the battery from outputting power.

[0084] During specific implementation, in order to prevent charged components such as batteries, switching circuits, VR chips, MCUs and ADC chips from being affected by foreign objects or assembly, an isolation protective cover can be set up, and the charged components of the device of this embodiment can be placed in the protective cover to ensure that the substrate deformation detection and alarm system can work normally during the substrate assembly and transportation.

[0085] An embodiment of a PCB substrate deformation detection device has been described in detail above. Based on the PCB substrate deformation detection device described in the above embodiment, an embodiment of the present invention further provides a PCB substrate deformation detection method corresponding to the device.

[0086] Figure 7This is a flow chart of a PCB substrate deformation detection method provided by an embodiment of the present invention. Figure 7 As shown, the method includes the following steps.

[0087] S1, place the strain gauge at the location to be detected on the PCB substrate.

[0088] S2, collects the deformation of the strain gauge.

[0089] S3, determines the deformation state of the PCB substrate based on the deformation amount of the strain gauge, and issues an alarm when the deformation state exceeds a threshold.

[0090] Wherein, step S3 specifically includes:

[0091] 1) When the system is online, the BMC determines the relationship between the deformation and the alarm threshold. If the deformation exceeds the first-level alarm threshold but is less than the second-level alarm threshold, it uploads a normal alarm message. If the deformation exceeds the second-level alarm threshold, it uploads an emergency alarm message and restricts system power on.

[0092] 2) When the system is offline, the MCU determines the relationship between the deformation and the alarm threshold. If the deformation exceeds the first-level alarm threshold but is less than the second-level alarm threshold, it stores the normal alarm information and the corresponding deformation information. If the deformation exceeds the second-level alarm threshold, it stores the emergency alarm information and the corresponding deformation information.

[0093] 3) Each time the BMC is powered on, it first collects the storage information of the MCU, and then uploads the alarm information and powers on the system based on the stored information.

[0094] Specifically, when the system is offline, the ADC chip converts the voltage analog signals collected by CH1~CHn into digital signals and transmits them to the MCU through the I2C bus. The MCU compares the digital signals obtained through I2C with the two-level alarm thresholds set internally. When the obtained digital signal is less than the internally set threshold, it proves that the deformation of the substrate has not exceeded the safety baseline. When the obtained digital signal is greater than the first-level alarm threshold and less than the second-level alarm threshold, it proves that the bending deformation of the substrate exceeds the safety baseline and triggers the general alarm mechanism. When the obtained digital signal is greater than the second-level alarm threshold, it proves that the bending deformation of the substrate exceeds the safety baseline extremely and triggers the fatal alarm mechanism. The MCU temporarily stores the alarm level and alarm position. After the system power is connected, the alarm level and alarm position information are transmitted to the BMC through I2C. The BMC uploads the alarm information and powers on the system according to the alarm level.

[0095] The PCB substrate deformation detection method of this embodiment is implemented based on the aforementioned PCB substrate deformation detection device. Therefore, the specific implementation of this method can be found in the embodiment section of the PCB substrate deformation detection device in the previous text. Therefore, its specific implementation can refer to the description of the corresponding embodiments of each part and will not be elaborated here.

[0096] In addition, since the PCB substrate deformation detection method of this embodiment is implemented based on the aforementioned PCB substrate deformation detection device, its function corresponds to that of the aforementioned device and will not be described in detail here.

[0097] The above disclosure is only a preferred embodiment of the present invention, but the present invention is not limited thereto. Any non-creative changes that can be thought of by those skilled in the art, as well as several improvements and modifications made without departing from the principles of the present invention, should fall within the scope of protection of the present invention.

Claims

1. A PCB substrate deformation detection device, characterized in that: It includes a deformation detection unit, a data processing unit and a power supply unit; Deformation detection unit: includes a strain gauge and a strain acquisition circuit. The strain gauge is set at the detection location on the PCB substrate. The strain acquisition circuit is connected to the strain gauge to collect the deformation of the strain gauge and send the collected deformation information to the data processing unit. Data processing unit: receives deformation information, determines the deformation state of the PCB substrate based on the deformation information, and issues an alarm and / or restricts system power-on when the deformation state exceeds a threshold; Power supply unit: connected to the deformation detection unit and data processing unit respectively, providing power to the deformation detection unit and data processing unit when the system is online or offline; The data processing unit includes MCU and BMC; The MCU is connected to the BMC and determines whether the system is in place based on the BMC signal; the output end of the analog-to-digital conversion chip is connected to the MCU and BMC respectively; When the system is online, the analog-to-digital conversion chip transmits the output deformation information to the BMC. The BMC determines the relationship between the deformation and the alarm threshold. If the deformation exceeds the first-level alarm threshold but is less than the second-level alarm threshold, it uploads a normal alarm message. If the deformation exceeds the second-level alarm threshold, it uploads an emergency alarm message and restricts system power supply. When the system is offline, the MCU collects the deformation information output by the analog-to-digital conversion chip. The MCU determines the relationship between the deformation and the alarm threshold. If the deformation exceeds the first-level alarm threshold but is less than the second-level alarm threshold, the MCU stores the normal alarm information and the corresponding deformation information. If the deformation is higher than the second-level alarm threshold, the emergency alarm information and the corresponding deformation information are stored; Each time the BMC is powered on, it first collects the stored information of the MCU, and then uploads alarm information and powers on the system based on the stored information. The BMC is connected to the CPLD, which is connected to the enable pin of the system power supply VR chip. When the BMC detects an emergency alarm, the CPLD triggers the system power supply VR chip to stop working, thereby limiting system power supply. The power supply unit includes a battery, a switching circuit, a detection power supply VR chip and a charging circuit; The control end of the switching circuit is connected to the MCU, the input end is connected to the battery and system power supply respectively, and the output end supplies power to the MCU and analog-to-digital conversion chip; the MCU outputs a control signal to the switching circuit. When the system is online, the system power supply supplies power to the detection power supply VR chip. When the system is offline, the battery supplies power to the detection power supply VR chip. The system power supply is also connected to the battery via a charging line.

2. The PCB substrate deformation detection device according to claim 1, characterized in that: The strain acquisition circuit includes: a second resistor, a third resistor, a first voltage regulator tube, a first capacitor and an analog-to-digital conversion chip; The first end of the second resistor is connected to the power supply voltage, the second end is connected to the negative electrode of the first voltage regulator tube, and the positive electrode of the first voltage regulator tube is grounded; the first capacitor is connected in parallel with the first voltage regulator tube; the first end of the third resistor is connected to the negative electrode of the first voltage regulator tube, and the second end is grounded via the strain gauge; and the second end of the third resistor is connected to the input end of the analog-to-digital conversion chip, and the output end of the analog-to-digital conversion chip is connected to the data processing unit.

3. The PCB substrate deformation detection device according to claim 1, wherein: Connect the MCU's ON pin to the BMC's GPIO1 pin, and connect a pull-down resistor to the line between the MCU's ON pin and the BMC's GPIO1 pin. When the system is in place, the GPIO1 pin of the BMC sends a high-level signal, and the ON pin of the MCU receives the high-level signal, judging that the system is in place; when the system is offline, the pull-down resistor clamps the ON pin level of the MCU to a low level, and the MCU judges that the system is offline.

4. The PCB substrate deformation detection device according to claim 3, characterized in that: The RST pin of the MCU is connected to the GPIO0 pin of the BMC. When the internal storage data of the MCU exceeds the threshold, the BMC resets the internal storage data of the MCU.

5. The PCB substrate deformation detection device according to claim 1, wherein: The switching circuit includes a first MOS transistor, a second MOS transistor, a third MOS transistor and a first resistor; wherein the first MOS transistor, the second MOS transistor and the third MOS transistor are all N-channel MOS transistors; The output end of the MCU is respectively connected to the gates of the first MOS transistor and the third MOS transistor, the drain of the first MOS transistor is connected to the battery, and the source of the first MOS transistor and the drain of the second MOS transistor are voltage output ends; the source of the second MOS transistor is connected to the system power supply, the gate of the second MOS transistor is connected to the second end of the first resistor, the first end of the first resistor is connected to the power supply voltage, and the second end of the first resistor is connected to the drain of the third MOS transistor, and the source of the third MOS transistor is grounded.

6. The PCB substrate deformation detection device according to claim 5, characterized in that: The PSON pin of the battery is grounded via a switch.

7. A PCB substrate deformation detection method, characterized in that: The method is implemented based on the device according to any one of claims 1 to 6, and comprises the following steps: Step 1: Place the strain gauge on the part to be detected on the PCB substrate; Step 2: Collect the deformation of the strain gauge; Step 3: Determine the deformation state of the PCB substrate based on the strain gauge deformation and issue an alarm when the deformation state exceeds a threshold, including: When the system is online, the BMC determines the relationship between the deformation and the alarm threshold. If the deformation exceeds the first-level alarm threshold but is less than the second-level alarm threshold, it uploads a normal alarm message. If the deformation exceeds the second-level alarm threshold, it uploads an emergency alarm message and restricts system power on. When the system is offline, the MCU determines the relationship between the deformation and the alarm threshold. If the deformation exceeds the first-level alarm threshold but is less than the second-level alarm threshold, the MCU stores the normal alarm information and the corresponding deformation information. If the deformation exceeds the second-level alarm threshold, the MCU stores the emergency alarm information and the corresponding deformation information. Each time the BMC is powered on, it first collects the storage information of the MCU, and then uploads alarm information and powers on the system based on the stored information.

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