CN107907817A - The experimental provision and experimental method of test and appraisal board quality under a kind of combinational environment - Google Patents

Abstract

The invention provides an experimental device for evaluating the quality of a circuit board in a composite environment, which includes a test box, a radio frequency system connected to the side wall of the test box to emit electromagnetic waves into the test box, and a radio frequency system for transmitting electromagnetic waves to the circuit board to be tested. A pulse voltage generation system for high-voltage discharge, a bracket for placing the circuit board to be tested, a power sensor for measuring the intensity of electromagnetic waves near the circuit board to be tested, and a data processing system. The present invention also provides an experimental method for evaluating the quality of circuit boards in a composite environment, using the above experimental device. The invention provides an experimental device and an experimental method for evaluating the quality of circuit boards in a composite environment, which can respectively detect the quality of circuit boards under conditions of different temperatures, radio frequency interference and high electric fields.

Description

An experimental device and experimental method for evaluating the quality of circuit boards in a composite environment

technical field

The invention relates to a testing device for circuit boards, in particular to an experimental device capable of evaluating the quality of circuit boards in a composite environment and a corresponding experimental method

Background technique

With the continuous improvement of rail transit capacity, EMUs, with their unique high speed, people choose more and more EMUs for travel. During the driving process of EMUs, the circuit boards of display system, broadcasting circuit and various other purposes are all In a complex electromagnetic environment, and all electronic equipment and control systems in each car of the EMU are installed in a centralized manner, resulting in local high temperature, these factors are the main factors that cause damage to the circuit board and lead to circuit failure.

At present, the research on the influence of electromagnetic interference on the performance of various circuit boards is mainly to complete the test through the authoritative experimental center. The test process is time-consuming and laborious. At the same time, the electromagnetic immunity test and the high-voltage damage test to electronic components are carried out separately, which cannot be effective. The evaluation of product quality is close to the actual working conditions of high-speed trains, so there is an urgent need for an experimental device and corresponding experimental methods that can accurately and quickly measure the quality of various circuit boards of EMUs under working conditions.

Contents of the invention

The main purpose of the present invention is to solve the above-mentioned problems and deficiencies, and provide an experimental device and an experimental method for evaluating the quality of circuit boards in a composite environment, which can test the quality of circuit boards under different temperatures, radio frequency interference, and high electric fields.

In order to achieve the above object, the present invention at first provides an experimental device for evaluating the quality of circuit boards in a composite environment, and its technical scheme is:

An experimental device for evaluating the quality of a circuit board in a composite environment, including a test box, and a radio frequency system connected to the side wall of the test box to emit electromagnetic waves into the test box, and a device for high-voltage discharge to the circuit board to be tested A pulse voltage generating system, a bracket for placing the circuit board to be tested, a power sensor for measuring the intensity of electromagnetic waves near the circuit board to be tested, and a data processing system.

Further, it also includes a temperature adjustment system capable of adjusting and controlling the internal temperature of the test box.

Further, the radio frequency system includes a radio frequency signal source connected to each other through a transmission line, a power control system, and a compound antenna. The power control system receives electromagnetic waves emitted by the radio frequency signal source, amplifies and processes them to a corresponding power, and transmits them to the radio frequency signal via the compound antenna. Electromagnetic waves are emitted in the test box.

Further, the power control system includes a power amplifier and a power control loop, the power amplifier is respectively connected to the radio frequency signal source, the composite antenna and the power control loop, and the power control loop is connected to the power sensor.

Further, the data processing system includes a data acquisition system and a data analysis and display system, and the data acquisition system transmits the collected pulse voltage signal, radio frequency power signal, temperature signal, and discharge information to the data analysis system for data analysis processed and displayed.

The present invention further provides an experimental method for evaluating the quality of circuit boards in a composite environment, which adopts the following technical scheme:

An experimental method for evaluating the quality of circuit boards in a composite environment, using the experimental device as described above, the testing process includes the following steps,

S1, the temperature adjustment device presets different control temperatures, and heats the test box to maintain the corresponding preset control temperature level in the box;

S2, the radio frequency system emits electromagnetic waves into the test box, and adjusts the intensity of electromagnetic waves around the area to be tested within a preset range through the power control system;

S3, when the temperature and electromagnetic waves around the circuit board to be tested are constant, the pulse voltage generation system is turned on, so that the circuit board to be tested is placed in a strong electric field, and the circuit board to be tested is subjected to a high-voltage discharge damage test in a composite environment, and the data collected during the test is collected. related signals;

S4, the data processing system performs corresponding processing on the signal collected in step S3, and calculates the quality grade evaluation coefficient of the circuit board under different composite environments;

S5, comparing the calculated evaluation system with the existing evaluation grading table to obtain the quality grade of the circuit board to be tested.

Further, the following formula is used to calculate the evaluation coefficient,

Among them, η is the evaluation coefficient, T is a certain preset temperature provided by the temperature control system, Γ board is the reflection coefficient of the circuit board, Γ air is the air reflection coefficient, Q is the discharge capacity of the circuit board obtained by the filter circuit, and P is set For a preset output power provided by the power control system, U is set to a preset pulse voltage provided by the pulse voltage system.

Further, when η>7.5, the quality grade is poor; when η≤7.5, and η>4.5, the quality grade is medium; when η≤4.5, and η>1.5, the quality grade is excellent.

Further, the data acquisition system is connected with the amplification and filtering circuit, and obtains the discharge amount information in the circuit board to be tested through the UHF antenna.

Further, the compound antenna is provided at the central parts of the six side walls of the test box.

In summary, compared with the prior art, the experimental device and method for evaluating the quality of circuit boards in a composite environment provided by the present invention has the following advantages:

1. The temperature in the test box is adjusted and controlled by the temperature adjustment system, and the heating control and monitoring are realized through a loop, so that the preset temperature in the box is maintained and the temperature of the test environment is stable;

2. Through the power control system, the electromagnetic wave signal emitted by the radio frequency signal source is amplified, and the intensity of the electromagnetic wave is adjusted in time according to the feedback of the power probe, so that the test box receives a stable preset electromagnetic wave, and through a loop, the electromagnetic wave signal is amplified, monitored, adjusted function;

3. The device can simulate the compound environment under different working conditions at the same time, and can adjust the working condition coefficient in the environment at any time according to the needs, so as to adapt to different circuit boards for testing.

Description of drawings:

Figure 1: A schematic diagram of a circuit board quality detection device in a composite environment of the present invention;

Figure 2: Schematic diagram of the structure of the test box in the circuit board quality detection device in a composite environment of the present invention;

Among them: transmission line 1, radio frequency system 2, data processing system 3, power control system 4, 220V AC power supply 5, radio frequency signal source 6, power amplifier 7, power control loop 8, UHF antenna 9, pulse voltage generation system 10, DC power supply 11, temperature adjustment system 12, amplification and filtering circuit 13, data acquisition system 14, DC power supply line 15, insulating support plate 16, composite antenna 17, support plate support 18, wave-absorbing material 19, test box 20, electric heating device 21. Temperature adjustment device 22, temperature sensor 25, power probe 26, circuit board 27, data analysis and display system 33, insulating material 36, lower part of pallet support 37, middle part of pallet support 38, upper part of pallet support 39,

Detailed ways

The present invention will be described in further detail below in conjunction with the accompanying drawings and specific embodiments.

The present invention provides an experimental device for evaluating the quality of a circuit board in a composite environment, comprising a test box 20, and also including a radio frequency system 2 connected to the side wall of the test box 20 to emit electromagnetic waves in the test box 20, and to transmit electromagnetic waves to the circuit board to be tested. 27 a pulse voltage generation system 10 for high-voltage discharge, a bracket for placing the circuit board to be tested, a power probe 26 for measuring the intensity of electromagnetic waves near the circuit board 27 to be tested, and a data processing system 3 .

As shown in Figures 1 and 2, the test box 20 is a sealed structure, including six side walls that are mutually connected and fixed, and an insulating material 36 is provided inside, and a circuit board 27 to be tested (hereinafter referred to as a circuit board to be tested) is fixed on the bottom wall. The support of the circuit board 27), the support includes a supporting plate support 18 and an insulating supporting plate 16, the bottom wall of the supporting plate supporting plate 18 is fixed with the test box 20, the top is fixed with the insulating supporting plate 16, and the insulating supporting plate 16 is used to place the circuit board 27. At the same time, one or more temperature sensors 25 and power probes 26 are fixed on the upper surface of the insulating tray to sense the temperature around the circuit board and the intensity of electromagnetic waves. As shown in Figure 2, the pallet support 18 includes a pallet support lower section 37, a pallet support middle section 38, and a pallet support upper section 39 connected vertically in sequence, forming a pallet support 18 generally in a "ㄣ" shape, and a pallet support lower section The bottom of 37 is fixed with the bottom wall of test box 20, and the top of supporting plate support upper section installs insulating supporting plate 16, and three sections are cuboid structure.

In the embodiment provided by the present invention, the test box 20 is a cube with a side length of 2400mm, and the inside of the test box 20 is surrounded by an insulating material with a thickness of 3mm to form a cube space with a side length of 2350mm; the lower section 37 of the pallet support is a The length and width are 40mm, and the height is a cuboid of 1025mm. The middle section 38 of the supporting plate support is a cuboid with a length of 280mm, a width and a height of 40mm. Install a length and a width of 200mm in the supporting plate support upper section 39, and the thickness is the insulating supporting plate 16 of 10mm. The above is an example of the test box suitable for the circuit of the on-board display system provided by the present invention. In practical application, the specific dimensions of the test box 20 and the internal insulating support plate 16 and support plate support 18 can be determined according to the size of the circuit board to be tested.

As shown in Figure 1, the radio frequency system 2 is connected with the composite antenna 17 fixed on the inner wall of the test box 20 through the transmission line 1, including the 220V AC power supply 5, the RF signal source 6 and the power control system 4 connected in sequence, and the 220V AC power supply is The radio frequency signal source provides power, the radio frequency signal source 6 emits a certain power radio frequency signal, i.e. electromagnetic waves, the power control system 4 regulates and controls the electromagnetic wave signal emitted by the radio frequency signal source 6, the transmission line 1 is connected with the composite antenna 17, and sends to the test box 20 Electromagnetic waves of predetermined power are supplied internally. The power control system 4 includes a power amplifier 7, a power control circuit 8 and a power probe 26 fixed on the insulating support plate 16. The power amplifier 7 has three functional interfaces, which are respectively connected to the radio frequency signal source 6, the power control circuit 8 and the test box 20. The compound antenna 17 on the inner wall is connected, one end of the power control loop 8 is connected to the power amplifier 7 , and the other end is connected to the power sensor 26 on the insulating support plate 16 through the transmission line 1 .

Because what show in accompanying drawing 1 is the schematic diagram of test box 20, from the direction shown in Fig. 1, the compound antenna 17 that is installed on the front and back of inner wall is invisible, therefore, in Fig. 1, two shorter dotted lines Represent the transmission line 1 connected to the compound antenna 17 fixed on the front and back of the inner wall, and another longer dashed line represents the transmission line 1 bypassing the back of the test box 20 and connected to the compound antenna 17 on the right side.

220V AC power supply 5 supplies power for radio frequency signal source 6, and radio frequency signal source 6 inputs the high-frequency electromagnetic wave of output into power amplifier 7 to amplify and process, and uses high temperature resistant tape to fix composite antenna 17 on the inner wall of test box 20, provided in the present invention In the embodiment, there are 6 composite antennas 17, which are respectively fixed in the center of the six faces of the inner wall of the test box 20, so that the electromagnetic wave signal inside the test box 20 is balanced, and each composite antenna 17 is communicated with the power amplifier 7 through the transmission line 1 respectively, The electromagnetic wave signal transmitted by the power amplifier 7 is received, and the electromagnetic wave is emitted into the test box 20 . A wave-absorbing material 19 is pasted on the inner wall of the test box 20 to absorb residual electromagnetic waves and prevent electromagnetic waves from radiating outside the device. Fix the power probe 26 on the insulating support plate 16 with a heat-resistant adhesive tape to detect the electromagnetic wave power near the circuit board 27, and control and adjust the electromagnetic wave environment around the circuit board 27 by controlling the detected electromagnetic wave power through the power amplifier 7 .

In order to achieve a composite environment in the test box 20, the experimental device is also provided with a temperature adjustment system 12 that can adjust and control the temperature inside the test box, including an electric heating device 21, a temperature sensor 25 and a temperature adjustment device 22. The heating device 21 is fixed on the inner wall of the test box 20 to prevent the electric heating device 21 from falling off on the inner wall under high temperature conditions, and the temperature sensor 25 is also fixed on the insulating support plate 16 by using high temperature resistant tape to accurately sense the heating temperature around the circuit board 27 , to avoid distortion of the detected temperature signal, or internal temperature imbalance, the temperature sensor 25 can be multiple, and the position is balanced on the periphery of the circuit board 27. Similarly, there are multiple power probes 26, and the position is balanced on the circuit board 27. Peripheral, the arrangement of the temperature sensor 25 and the power sensor 26 needs not to affect the balance of the circuit board 27 and be placed horizontally. The DC power supply 11 supplies power to the electric heating device 11 through the DC power supply line 15, so that the electric heating device 11 works, and the temperature of the test box 20 is raised to a predetermined temperature. The device 22, the temperature regulating device 22 controls the temperature near the circuit board 27 by controlling the power of the DC power supply 11. In the embodiment provided by the present invention, the electric heating device 21 can be an electric heating wire, and in practical applications, any other device that can realize electric heating can also be used.

The pulse voltage generating system 10 is connected with the circuit board 27, and is used to generate pulse voltage, generate high voltage, and generate electric fields of different strengths, and conduct high-voltage discharge tests on the circuit board 27. The discharge signal generated on the circuit board 27 is passed through the ground amplification filter circuit 13 for preliminary signal processing, and then the data processing system 3 collects the discharge amount information and performs data analysis and processing.

The data processing system 3 includes a data acquisition system 14 and a data analysis and display system 33. The data acquisition system 14 transmits the collected pulse voltage signal, radio frequency power signal, temperature signal, and discharge information to the data analysis and display system 33 for data analysis and processing , and display.

The present invention simultaneously provides an experimental method for evaluating the quality of a circuit board in a composite environment, comprising the following steps:

S1, connect the DC power supply 11, heat the inner wall of the test box 20, preset different control temperatures for the temperature adjustment device 22, and heat the test box 20, and adjust the DC power supply in time through the temperature signal detected by the temperature sensor 25 11 output power, so that the box is maintained at the corresponding preset control temperature level;

S2, connect the 220V AC power supply 5, the radio frequency system 2 emits electromagnetic waves into the test box 20, and adjust the electromagnetic wave intensity around the circuit board 27 to be tested through the power control system within a preset range;

S3, the temperature and electromagnetic waves around the circuit board to be tested 27 are constant, and the pulse voltage generating system 10 is turned on, so that the circuit board to be tested is placed in a strong electric field, and the circuit board to be tested is subjected to a high-voltage discharge damage test in a composite environment, and the amplification and filtering circuit is turned on 13 and data acquisition system 14, collecting relevant signals in the testing process;

S4, the data acquisition system 14 performs corresponding processing on the signals collected in step S3, and calculates the quality grade evaluation coefficients of the circuit boards in different composite environments.

Wherein, in the embodiment provided by the present invention, the following formula is used to calculate the evaluation coefficient:

Among them, η is the evaluation coefficient, T is a certain preset temperature provided by the temperature control system, Γ board is the reflection coefficient of the circuit board, Γ air is the air reflection coefficient, Q is the discharge capacity of the circuit board obtained by the filter circuit, and P is set A preset output power of electromagnetic waves provided by the power control system, U is set to a preset pulse voltage provided by the pulse voltage system.

In practical applications, the electromagnetic wave power, temperature and pulse voltage values in the complex environment in steps S1 to S4 can be repeated infinitely, and the evaluation coefficients under different conditions can be calculated respectively. At the same time, the high-voltage discharge test can be performed only according to the electromagnetic wave power and temperature in the most common compound environment during use of the circuit board 27, and the evaluation coefficient can be further calculated to evaluate the quality of the circuit board 27.

S5, comparing the calculated evaluation system with the existing evaluation grading table to obtain the quality grade of the circuit board to be tested.

In the embodiment provided by the present invention, taking the circuit board of the vehicle-mounted display system as an example, the relevant data is collected by the aforementioned method, and the evaluation coefficient is calculated by the above formula. When η>7.5, the quality level is poor; when η≤7.5, and When η>4.5, the quality level is medium; when η≤4.5, and η>1.5, the quality level is excellent. In practical applications, circuit boards with similar purposes or use environments can be classified according to the above-mentioned data range in the quality level of the circuit board composite environment, or only refer to the above-mentioned data, or in practical applications, the test device provided by the present invention can be used As well as the test method, conduct a large number of experiments on the circuit board, summarize the experimental data and the quality of the corresponding circuit board, and summarize the data range of the quality level of the circuit board.

In summary, compared with the prior art, the experimental device and method for evaluating the quality of circuit boards in a composite environment provided by the present invention has the following advantages:

1. The temperature in the test box is adjusted and controlled by the temperature adjustment system, and the heating control and monitoring are realized through a loop, so that the preset temperature in the box is maintained and the temperature of the test environment is stable;

2. Through the power control system, the electromagnetic wave signal emitted by the radio frequency signal source is amplified, and the intensity of the electromagnetic wave is adjusted in time according to the feedback of the power probe, so that the test box receives a stable preset electromagnetic wave, and through a loop, the electromagnetic wave signal is amplified, monitored, adjusted function;

3. The device can simulate the compound environment under different working conditions at the same time, and can adjust the working condition coefficient in the environment at any time according to the needs, so as to adapt to different circuit boards for testing.

As mentioned above, a similar technical solution can be derived in combination with the content of the given solution. However, any simple modifications, equivalent changes and modifications made to the above embodiments according to the technical essence of the present invention are still within the scope of the technical solutions of the present invention.

Claims (10)

1. a kind of experimental provision for board quality of testing and assessing under combinational environment, including test box, it is characterised in that：Further include and institute State test box wall box and connect and launch the radio frequency system of electromagnetic wave into the test box, put to circuit board under test into horizontal high voltage The pulse voltage generating system of electricity, the stent for placing circuit board under test, the power for measuring electromagnetic intensity near circuit board under test Probe and data handling system.

2. the experimental provision for board quality of testing and assessing under a kind of combinational environment as claimed in claim 1, it is characterised in that：Also wrap Include humidity control system that is adjustable and controlling the test box internal temperature.

3. the experimental provision for board quality of testing and assessing under a kind of combinational environment as claimed in claim 1, it is characterised in that：It is described Radio frequency system includes radio-frequency signal source, power control system and the combined antenna being connected with each other by transmission line, the power control System processed receives the electromagnetic wave of radio-frequency signal source transmitting, through combined antenna to the test box after enhanced processing to corresponding power Transmitting electromagnetic wave in vivo.

4. the experimental provision for board quality of testing and assessing under a kind of combinational environment as claimed in claim 3, it is characterised in that：It is described Power control system includes power amplifier and power control circuit, the power amplifier respectively with the radio-frequency signal source, Combined antenna and power control circuit connection, the power control circuit are connected with the power probe.

5. such as the experimental provision for board quality of testing and assessing under a kind of combinational environment of Claims 1-4 any one of them, its feature It is：The data handling system includes data collecting system, processing and display system, and the data collecting system is by collection Pulse voltage signal, rf power signal, temperature signal, discharge capacity information are transferred to the data analysis system and carry out data point Analysis is handled, and is shown.

A kind of 6. experimental method for board quality of testing and assessing under combinational environment, it is characterised in that：Use such as claim 1 to 5 times Experimental provision described in one, test process include the following steps,

S1, temperature-adjusting device presets different control temperature, and test box is heated, and makes to maintain corresponding default control in case Temperature levels processed；

S2, radio frequency system launches electromagnetic wave into test box, and the electromagnetic wave adjusted by power control system around to be measured is strong Degree is within a preset range；

S3, the temperature and electromagnetic wave enclosed around circuit board under test reach constant, and unbalanced pulse electric voltage generating system, makes circuit under test Plate is under highfield, electrion damage measure is carried out to circuit board under test in combinational environment, during collecting test Coherent signal；

S4, data handling system do corresponding processing to the signal gathered in step S3, are calculated under different composite environment electric The credit rating metewand of road plate；

S5, the assessment system being calculated are compareed with existing Assessment for classification table, draw the credit rating of circuit board under test.

7. the experimental method for board quality of testing and assessing under a kind of combinational environment as claimed in claim 6, it is characterised in that：Using Equation below calculates metewand,

Wherein, η is metewand, and T is a certain preset temperature that temperature control system provides, Γ_PlateFor circuit board reflectance factor, Γ_AirFor air reflection coefficient, Q_SurveyThe discharge capacity of the circuit board obtained for filter circuit, P_IfCertain provided for power control system One default output power, U_IfThe a certain predetermined pulse voltage provided for pulse voltage system.

8. the experimental method for board quality of testing and assessing under a kind of combinational environment as claimed in claim 6, it is characterised in that：Work as η> When 7.5, credit rating is poor, when η≤7.5, and η>When 4.5, during credit rating is, when η≤4.5, and η>When 1.5, quality etc. Level is excellent.

9. the experimental method for board quality of testing and assessing under a kind of combinational environment as claimed in claim 6, it is characterised in that：It is described Data collecting system is connected with amplification filter circuit, and the discharge capacity information in circuit board under test is obtained by UHF antenna.

10. the experimental provision for board quality of testing and assessing under a kind of combinational environment as claimed in claim 3, it is characterised in that：Institute The central part for stating six side walls of test box is both provided with the combined antenna.