A method for checking the hardware improvement of circuit board startup

Abstract

The invention relates to the technical field of circuit lines and electronic circuit hardware, and in particular to an inspection method for improving the startup hardware of a circuit board, comprising the following steps: S1, standardizing the positions of test points: it is necessary to arrange a special area on the circuit board to place power supply test points with equal spacing of 2.54 mm, use magnetic beads to isolate the power supply of multiple loads, extract the test points of the rear-stage power supply, and place them in a unified test point placement area; S2, impedance testing: use a 2.54 mm pin header to make an impedance test probe, and use a self-made probe-type impedance tester to quickly and accurately test all test points; the impedance tester mainly includes an MCU, a resistance measurement module, a power supply module, an OLED display module and a JTAG interface; after the test point positions are standardized, the impedance can be tested more conveniently and automatically or manually, and the time for finding the test points can be reduced; using the self-made impedance tester, the impedance of all test points that need to be tested can be scanned more conveniently and quickly.

Description

Technical Field

[0001] The invention relates to the technical field of circuit lines and electronic circuit hardware, and in particular to an inspection method for improving the startup hardware of a circuit board. Background Art

[0002] 1. Basic situation of traditional technology

[0003] my country is a major manufacturing country, and the number of electronic products produced each year is also increasing year by year, covering all aspects from civilian to military use.

[0004] With the rapid development of electronic technology, the performance requirements of electronic products are getting higher and higher. The more complex the PCB wiring becomes (the larger the area and the more layers), the higher the value. It is particularly necessary to effectively check the hardware of the produced circuit board before starting. Among them, the impedance test and inspection of the related circuits are more important. All problems need to be nipped in the bud.

[0005] 2. Disadvantages of traditional methods

[0006] For circuits that have already been produced, most people just take a quick look at the circuit's appearance, and there will be corresponding impedance testing before leaving the factory. However, when they are transported to the site of use, few people check the impedance of the relevant circuits, or use manual methods to detect the impedance.

[0007] Several methods of traditional circuit board startup hardware inspection methods have the following main disadvantages:

[0008] (1) Manual single impedance detection is cumbersome and the test is inaccurate.

[0009] (2) There are no fixed test points. The search for test points on the entire circuit board is too wide. Dedicated and expensive equipment is required for testing, which is not suitable for on-site use. Summary of the invention

[0010] In view of the deficiencies in the prior art, the present invention provides an inspection method for improving the startup hardware of a circuit board, which standardizes the arrangement of test points in the circuit board design. It is necessary to arrange a special area on the circuit board to place power supply test points with equal spacing of 2.54mm. For the power supply with multiple loads, magnetic beads are used for isolation, and the test points of the subsequent power supply are extracted and placed in a unified test point placement area; an impedance test probe is made using a 2.54mm pin header, and an electronic switch is used to switch different channels, and an impedance test is performed on the single-chip microcomputer, and the value is recorded; an impedance test is performed before each power-on to reduce the risk of damaging the board during power-on.

[0011] The present invention is achieved through the following technical solutions:

[0012] A method for checking circuit board startup hardware improvement, comprising the following steps:

[0013] S1. Standardize the test point location: It is necessary to arrange a special area on the circuit board to place power test points with equal spacing of 2.54mm. For the power supply with multiple loads, use magnetic beads to isolate, and extract the test points of the subsequent power supply and place them in the unified test point placement area;

[0014] S2. Impedance test: Use 2.54mm pin header to make impedance test probe, and use self-made probe impedance tester to test all test points quickly and accurately;

[0015] The impedance tester mainly includes an MCU, a resistance measurement module, a power module, an OLED display module and a JTAG interface.

[0016] The MCU is used to drive the DDS chip, the AD chip, and process the collected data; the MCU uses the STM32F103ZET6 chip;

[0017] The resistance measurement module mainly includes a DA module and an AD module; the DA module controls the output current signal and injects it into the test point to be tested, and the voltage value of the test point to the ground is collected by the AD module to calculate the impedance of each test point;

[0018] The power module is used to convert the external power supply into a low voltage through the power module, so as to provide a stable and reliable power supply for each functional module;

[0019] The OLED display module: the MCU can output relevant parameters to the OLED display screen through the SPI interface;

[0020] The JTAG interface: By upgrading the system software through the JTAG interface, the system functions can be remotely updated without disassembling the machine.

[0021] When the impedance tester using the MCU as the STM32F103ZET6 chip is used, the specific steps are as follows:

[0022] 1) First, configure the reference ground position of the test point, the number of test points and the position of the test end through the device side, and manually set or learn to set the ground resistance of each test point of the normal board;

[0023] 2) Then the MCU drives the DA chip to generate test current, which is injected into different test points through the switching of multi-channel analog electronic switches to form a loop with the reference ground;

[0024] 3) Finally, the voltage signal to ground is sent to the AD terminal through a multi-way analog switch, and the voltage and current ratio is calculated by the STM32F103ZET6 chip. The impedance of each test point is displayed on the OLED display screen, and can be compared with the preset resistance. The abnormal test points that exceed the threshold are specially displayed, and relevant results are tested more quickly.

[0025] Preferably, the operating main frequency of the STM32F103ZET6 chip can reach 72MHZ, with up to 3 SPI interfaces, and can drive a DDS chip, an AD chip and a TFT touch color screen.

[0026] Preferably, the power module is a LM1117 power module.

[0027] The beneficial effects of the present invention are:

[0028] (1) After the test point location is standardized, the impedance can be tested automatically or manually more conveniently, reducing the time spent on finding the test point.

[0029] (2) Using a homemade impedance tester, the impedance of all test points can be scanned more conveniently and quickly. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0031] Figure 1 It is the placement form of the test points in the present invention;

[0032] Figure 2 It is the overall technical block diagram of the impedance tester in the present invention;

[0033] Figure 3 The schematic diagram of the impedance tester circuit in the present invention;

[0034] Figure 4 It is the hardware schematic diagram module of LM1117 in the present invention;

[0035] Figure 5 This is the MCU hardware schematic diagram in the present invention;

[0036] Figure 6 This is a schematic diagram of the JTAG interface hardware in the present invention;

[0037] Figure 7 This is a schematic diagram of the OLED display interface in the present invention;

[0038] Figure 8 It is the OLED display interface of the test point results in the present invention.

[0039] In the figure: 1-MCU, 201-DA module, 202-AD module, 3-power module, 4-OLED display module, 5-JTAG interface. DETAILED DESCRIPTION

[0040] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are 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.

[0041] A method for checking circuit board startup hardware improvement, comprising the following steps:

[0042] S1. Standardize the test point location: It is necessary to arrange a special area on the circuit board to place power test points with equal spacing of 2.54mm. For the power supply with multiple loads, use magnetic beads to isolate, and extract the test points of the subsequent power supply and place them in the unified test point placement area;

[0043] S2. Impedance test: Use 2.54mm pin header to make impedance test probe, and use self-made probe impedance tester to test all test points quickly and accurately;

[0044] The impedance tester mainly includes an MCU 1 , a resistance measurement module, a power supply module 3 , an OLED display module 4 and a JTAG interface 5 .

[0045] MCU1: used to drive the DDS chip, drive the AD chip, and process the collected data; MCU1 uses the STM32F103ZET6 chip;

[0046] Resistance measurement module: mainly includes DA module 201 and AD module 202; DA module 201 controls the output current signal and injects it into the test point to be tested, and collects the voltage value of the test point to the ground through AD module 202 to calculate the impedance of each test point;

[0047] Power module 3: used to convert the external power supply into low voltage through the power module 3, so as to provide stable and reliable power supply for each functional module;

[0048] OLED display module 4: MCU1 can output relevant parameters to the OLED display screen through the SPI interface;

[0049] JTAG interface 5: The system software can be upgraded through JTAG interface 5, and the system functions can be remotely updated without disassembling the machine.

[0050] When using an impedance tester with MCU1 as the STM32F103ZET6 chip, the specific steps are as follows:

[0051] 1) First, configure the reference ground position of the test point, the number of test points and the position of the test end through the device side, and manually set or learn to set the ground resistance of each test point of the normal board;

[0052] 2) Then MCU1 drives the DA chip to generate test current, which is injected into different test points through the switching of multi-channel analog electronic switches to form a loop with the reference ground;

[0053] 3) Finally, the voltage signal to ground is sent to the AD terminal through a multi-way analog switch, and the voltage and current ratio is calculated by the STM32F103ZET6 chip. The impedance of each test point is displayed on the OLED display screen, and can be compared with the preset resistance. The abnormal test points that exceed the threshold are specially displayed, and relevant results are tested more quickly.

[0054] Specifically, the STM32F103ZET6 chip can operate at a main frequency of up to 72MHZ, with up to 3 SPI interfaces, and can drive DDS chips, AD chips and TFT touch color screens.

[0055] Specifically, the power module 3 uses the LM1117 power module.

[0056] like Figure 1 The figure shows the test point placement form;

[0057] like Figure 2 The figure shows the overall technical block diagram of the impedance tester based on MCU1 single-chip control. The core control device is the STM32F103ZET6 chip of ST Company. It is an ARM 32-bit Cortex CPU with a maximum operating frequency of 72MHz and features such as ultra-low power consumption, which can meet actual application requirements.

[0058] like Figure 3 Shown is the circuit schematic diagram of the impedance tester;

[0059] like Figure 4 The hardware schematic diagram of LM1117 is shown in the figure. In terms of design, only the corresponding capacitors need to be configured to obtain a stable output voltage.

[0060] The system control acquisition processing chip uses ST's STM32F103ZET6 chip, which can drive DDS chip, drive AD chip, process collected data, etc.; the working main frequency can reach 72MHZ, up to 3 SPI interfaces 18M bits / second, can drive DDS, AD and TFT touch color screen, and its hardware schematic diagram is as follows Figure 5 As shown;

[0061] By upgrading the system software through the JTAG interface 5, the system functions can be remotely updated without disassembling the machine. The schematic diagram of the JTAG interface 5 is as follows: Figure 6 As shown;

[0062] MCU1 can output relevant parameters to the OLED display through the SPI interface. The schematic diagram of the OLED display interface is as follows: Figure 7 shown.

[0063] The improvement of the circuit board startup hardware method is mainly improved from two aspects. First, by standardizing the design of test points, the search for test points during testing is effectively reduced; second, by using a homemade probe-type impedance tester, all test points are tested quickly and accurately. The working principle of the new impedance tester circuit based on STM32 is as follows:

[0064] First, the position of the reference ground in the test point, the number of test points and the position of the test end are configured on the device side. The resistance to ground of each test point of the normal board can be set manually or by learning. Then MCU1 drives the DA chip to generate a test current, which is injected into different test points through the switching of multi-channel analog electronic switches to form a loop with the reference ground. Finally, the voltage signal to the ground is sent to the AD end through the multi-channel analog switch. The relationship between voltage and current is calculated by STM32, and the impedance of each test point is displayed on the OLED. It can be compared with the preset resistance, and the abnormal test points that exceed the threshold are specially displayed to test the relevant results more quickly. OLED display screen such as Figure 8 The OLED display interface shown.

[0065] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for checking the hardware improvement of a circuit board startup, characterized in that: The steps include: S1. Standardize the test point location: It is necessary to arrange a special area on the circuit board to place power test points with equal spacing of 2.54mm. For the power supply with multiple loads, use magnetic beads to isolate, and extract the test points of the subsequent power supply and place them in the unified test point placement area; S2. Impedance test: Use 2.54mm pin header to make impedance test probe, and use self-made probe impedance tester to test all test points quickly and accurately; The impedance tester mainly comprises an MCU (1), a resistance measurement module, a power supply module (3), an OLED display module (4) and a JTAG interface (5); The MCU (1) is used to drive the DDS chip, drive the AD chip, and process the collected data; the MCU (1) is a STM32F103ZET6 chip; The resistance measurement module mainly comprises a DA module (201) and an AD module (202); the DA module (201) controls the output current signal and injects it into the test point to be tested, and the voltage value of the test point to the ground is collected through the AD module (202), and the impedance of each test point is calculated; The power supply module (3) is used to convert externally provided power into a low voltage through the power supply module (3), thereby providing a stable and reliable power supply for each functional module; The OLED display module (4): the MCU (1) can output relevant parameters to the OLED display module (4) via an SPI interface; The JTAG interface (5): by upgrading the system software through the JTAG interface (5), it is possible to remotely update the system functions without disassembling the machine; When the impedance tester using the MCU (1) as an STM32F103ZET6 chip is used, the specific steps are as follows: First, the position of the reference ground in the test point, the number of test points and the position of the test end are configured on the device side, and the resistance to ground of each test point of the normal board can be set manually or by learning; Then the MCU (1) drives the DA chip to generate a test current, which is injected into different test points through the switching of a multi-channel analog electronic switch to form a loop with the reference ground; Finally, the voltage signal to the ground is sent to the AD terminal through a multi-channel analog switch, and the relationship between the voltage and the current is calculated through the STM32F103ZET6 chip. The impedance of each test point is displayed on the OLED display module (4), and can be compared with the preset resistance. The abnormal test point that exceeds the threshold is specially displayed, and the relevant results are tested more quickly; The impedance tester circuit comprises: a DA module (201), an AD module (202), a sampling resistor Rx, a PTC thermistor Rt, resistors R1 to R5, a transistor, a voltage-stabilizing diode and a multi-channel analog electronic switch; the input signal IN+ of the AD module (202) is respectively connected to the lower end of the PTC thermistor Rt and the upper end of the sampling resistor Rx, the lower end of the sampling resistor Rx is connected to the input signal IN- of the AD module (202) and the emitter and base of the transistor, and the input signal IN- of the AD module (202) is grounded, the upper end of the PTC thermistor Rt is sequentially connected in series with the resistors R1 to R5, and the upper end of the PTC thermistor Rt, the collector of the transistor and the reference voltage V of the AD module (202) are connected. REF - connected to the reference voltage V of the AD module (202) REF + are respectively connected to the input end of the multi-channel analog electronic switch, the upper end of the voltage-stabilizing diode and the power supply +V, the lower end of the voltage-stabilizing diode is grounded, the upper ends of the resistors R1 to R5 are all connected to multiple output ends of the multi-channel analog electronic switch and multiple test probes, and then output to a corresponding output end according to the switching of the multi-channel analog electronic switch; the MCU (1) drives the DA module (201) to generate a test current, which is injected into different test points through the switching of the multi-channel analog electronic switch to form a loop with the reference ground.

2. The inspection method for circuit board startup hardware improvement according to claim 1, characterized in that: The STM32F103ZET6 chip can operate at a main frequency of 72 MHZ, has up to 3 SPI interfaces, and can drive a DDS chip, an AD chip, and a TFT touch color screen.

3. The inspection method for circuit board startup hardware improvement according to claim 1, characterized in that: The power module (3) is a LM1117 power module.

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