Noise vibration temperature and humidity comprehensive environment simulation test system

Abstract

According to the noise vibration temperature and humidity comprehensive environment simulation test system provided by the invention, the multi-factor environment reverberation box, the noise loading device and the liquid nitrogen refrigeration system are designed, and the vibration table is adopted to apply vibration excitation, so that the noise vibration temperature and humidity comprehensive environment test capability is realized. According to the composite environment test requirements, a closed multi-factor environment reverberation box is utilized, a multi-environment simulation test space and various interfaces are provided, a strong noise environment is provided by adopting a noise loading device, noise environments of different magnitudes can be simulated, and temperature and humidity environments are applied to the noise environment at the same time; the sound transmission and heat insulation design is adopted, the interference effect of the loading noise of the pneumatic loudspeaker on the temperature and humidity environment is eliminated, and the environment adaptability and reliability assessment test can be carried out on the tested product.

Description

Technical Field

[0001] This invention belongs to the field of composite environmental testing applications, specifically relating to a comprehensive environmental simulation test system for noise, vibration, temperature, and humidity. Background Technology

[0002] Advances in science and technology have propelled the rapid development of electronic equipment towards intelligence, informatization, and intensification. The integrated design technology of mechatronics and information has significantly enhanced my country's information security capabilities. High-reliability components in electronic equipment mainly include carriers, chips, and circuitry. After assembly, critical components such as chips are protected in a fixed atmosphere using hermetically sealed packaging methods to ensure long-term product reliability. Currently, numerous reliability issues exist in the microstructures of current device chips. Mismatches in the thermal expansion coefficients of MEMS chips, bonding materials, and substrates can generate thermal stress, causing deformation of the chip's microstructure. Long-term high-low temperature cycling can lead to mechanical fatigue due to cyclic deformation of the microstructure, ultimately affecting the product's lifespan and long-term reliability. Under high-overload conditions, the internal microstructures of devices may experience fracture or plastic deformation after acoustic and vibration impacts, severely impacting product output and reliability. The wafer-level packaging of chips within devices typically employs a high-vacuum environment. Changes in chip operating temperature affect the vibration frequency and damping characteristics of resonant devices, thus impacting the device's high-temperature reliability. Moisture in the packaging equipment turns into gas at high temperatures, forming saturated water vapor. As the amount of vapor increases, vapor pressure is generated inside the package. When the pressure reaches a certain level, cracks are generated at the stress concentration weak points in order to release the pressure. Cracks start to form in the plastic package from the inside, causing delamination and cracking.

[0003] Currently, the technology for evaluating and verifying the environmental adaptability and reliability of electronic equipment is still imperfect, and most evaluation tests are single-factor tests. Multi-factor comprehensive environmental testing technology, which comprehensively considers environmental characteristics such as noise, vibration, temperature, and humidity, is not yet fully developed. Therefore, researching multi-factor comprehensive environmental testing systems for electronic components and establishing testing devices that closely resemble the working environment to fully evaluate the environmental adaptability and reliability of electronic components throughout their entire life cycle can effectively support the improvement of their environmental adaptability and reliability capabilities. A composite testing system capable of simulating the real working environment of electronic equipment is needed to conduct environmental adaptability and reliability evaluation tests, which is of great significance for improving the overall performance of electronic information equipment. Summary of the Invention

[0004] The purpose of this invention is to solve the problems existing in the prior art and provide a comprehensive environmental simulation test system for noise, vibration, temperature, and humidity. This system integrates vibration and noise-induced environmental simulation equipment with natural environmental simulation equipment for temperature and humidity by employing small-scale reverberation sound field technology, sound transmission and heat insulation technology, and temperature, humidity, and vibration simulation technology. Addressing the environmental adaptability and reliability verification needs of electronic components, it more realistically simulates the environmental loads throughout the entire life cycle of electronic components, improving the effectiveness and convenience of environmental adaptability and reliability testing.

[0005] The basic structural form of the noise, vibration, temperature, and humidity integrated environmental simulation test system provided by this invention is a box structure, consisting of a noise simulation device, a vibration table, a temperature simulation device, and a humidity simulation device. The vibration table is placed below the box, with its surface flexibly connected to the bottom of the box. The temperature and humidity simulation devices load the temperature and humidity of the convective gas inside the box through interfaces with the box. A high-power electric airflow loudspeaker is used as the sound source, connected to the side wall of the box, and a sound-absorbing exhaust channel is set at the top of the box. The box is divided into two areas by a sound-permeable insulation layer: a noise loading zone and a temperature, humidity, and vibration loading zone. Its functions are: ① to ensure that the noise zone is not affected by the temperature and humidity airflow (protecting the microphone and the electric airflow loudspeaker); ② to ensure that the temperature and humidity zone is not interfered with by the ambient temperature airflow used by the airflow loudspeaker (protecting the uniformity of the temperature and humidity field); ③ to eliminate the dissipation of the temperature and humidity environment inside the box through the loudspeaker.

[0006] The comprehensive environmental testing system for noise, vibration, temperature, and humidity allows for individual testing of each environmental stress or simultaneous loading to apply a comprehensive environmental load to the test specimen. The test chamber is a reverberation chamber, generating a diffuse sound field within. Microphones are arranged inside the chamber for sound field averaging control. The test specimen is mounted on the vibration table's extended platform using fixtures. Vibration control points are installed on both the test specimen and the vibration extended platform for multi-point averaging control. The area inside the chamber, excluding the noise loading zone outside the sound-permeable insulation layer, constitutes the effective comprehensive test zone. During the test, each individual environment is independently controlled in a closed loop, but all are integrated into a single measurement and control platform at the terminal. Loading is coordinated according to the test profile, and environmental parameters are collected until the entire test process is completed.

[0007] The process of simulating the integrated environment is as follows:

[0008] First, the noise controller of the noise simulation device transmits the drive signal of sound spectrum and magnitude to the power amplifier for amplification, which in turn drives the moving coil inside the electric airflow loudspeaker. At this time, high-pressure gas is sent into the electric airflow loudspeaker, and the airflow passes through the slit between the moving and stationary coils, thus generating sound. Subsequently, the sound wave is transmitted through the horn tube to the reverberation chamber, exciting the air inside the reverberation chamber to generate pulsating pressure. A microphone collects the sound pressure signal inside the reverberation chamber and feeds the signal back to the noise controller to correct its drive signal, thereby achieving closed-loop control of the noise system and ultimately ensuring that the sound pressure in the reverberation chamber meets the required magnitude and sound spectrum.

[0009] Since the speaker head requires pressurized gas to produce sound, the continuous inflow of gas into the chamber significantly affects the temperature and humidity. To reduce the interference of the noise subsystem on the temperature and humidity environment of the test space inside the chamber, the sound-generating area and the temperature and humidity area are designed separately. A sound-absorbing exhaust channel and a sound-permeable insulation layer are installed inside the chamber. The gas driving the speaker head is blocked by the sound-permeable insulation layer after entering the chamber and cannot enter the temperature and humidity loading area. Instead, it is directly discharged to the outside through the sound-absorbing exhaust channel. The sound field is connected and the temperature field is isolated through the sound-permeable insulation membrane.

[0010] A vibration table is an actuator that converts electrical energy into mechanical energy. It is mainly used for vibration intensity and shock environment testing of electronic products, environmental stress screening testing, and reliability testing. It can perform vibration testing of specimens in the vertical direction and can meet the requirements of sinusoidal, random, and shock tests with a wide frequency range, large displacement stroke, and high acceleration values.

[0011] The temperature simulation device includes a heating unit and a cooling unit. The heating unit's function is to raise the temperature of the gas inside the reverberation chamber, thus achieving the high-temperature environment required for the experiment. The heating unit uses a high-efficiency electronic heater, which is the heating element. The controller collects temperature data from the temperature sensor inside the reverberation chamber, performs closed-loop control calculations, and adjusts the duty cycle of the solid-state relay (SSR) to regulate the output power of the electronic heater, thereby achieving the closed-loop heating function.

[0012] The function of the refrigeration device is to cool the temperature of the gas inside the reverberation chamber, thereby achieving the required low-temperature environment for the experiment. This invention employs compressor refrigeration and liquid nitrogen-assisted refrigeration to cool the gas inside the reverberation chamber. The compressor refrigeration compresses the gaseous refrigerant into a high-temperature, high-pressure liquid refrigerant, which is then sent to the condenser for heat dissipation, becoming a medium-temperature, medium-pressure liquid refrigerant. The liquid refrigerant passes through an expansion valve and enters the evaporator. The sudden increase in space and decrease in pressure causes the liquid refrigerant to vaporize, absorbing a large amount of heat. The evaporator cools down, and the circulating gas inside the reverberation chamber flows through the evaporator, exchanging heat with it via convection. The evaporator absorbs the heat from the gas inside the reverberation chamber, thus cooling the gas. The gaseous refrigerant then returns to the compressor for further compression and circulation. Liquid nitrogen-assisted refrigeration utilizes the latent heat of vaporization of liquid nitrogen. Liquid nitrogen is piped to the reverberation chamber's duct, where it vaporizes and absorbs heat from the gas inside the reverberation chamber, lowering its temperature. The latent heat of liquid nitrogen vaporization directly exchanges heat with the gas in the reverberation chamber, which is highly efficient and can reach high temperature and cryogenic low temperature ranges.

[0013] The humidity simulation device uses a pressure-controlled electrically heated steam generator to provide steam. A heater is inserted into the water; as the heater temperature rises, it heats the water in the steam generator, producing saturated steam under pressure. This method directly converts electrical energy into heat energy with almost no energy loss, making it much more efficient than traditional steam generators. An electric steam regulating valve opens when humidification is needed. When it's necessary to reduce humidity inside the reverberation chamber, the humidity simulation device introduces some refrigerant from the refrigeration unit into the dehumidifying evaporator. As the refrigerant evaporates in the evaporator, it absorbs a large amount of heat, lowering the evaporator surface temperature below the condensation point of the humid air inside the chamber. This causes water vapor to condense into water, reducing the humidity level inside the chamber. The condensate is discharged through the reverberation chamber drain pipe. Humidity control is achieved through the combined action of a humidifying solenoid valve and a dehumidifying expansion valve, based on the target humidity and the actual humidity value inside the chamber, to achieve precise humidity control.

[0014] This invention is the first to realize the design of a comprehensive test system for multiple environmental factors such as noise, vibration, temperature and humidity. It can realistically simulate the working environment of electronic components in aerodynamic noise, vibration, temperature and humidity, and provides a test solution for the reliability and environmental adaptability of electronic components.

[0015] The beneficial effects of this invention are as follows:

[0016] 1. This invention adopts a modular design method to form a comprehensive test system for multiple environmental factors, realizing comprehensive environmental simulation of noise, vibration, temperature and humidity, and realistically simulating the working environment of electronic components, which can meet the environmental adaptability and reliability verification of electronic components;

[0017] 2. This invention uses small reverberation chamber sound field control technology to construct a small reverberation test chamber, which is the first comprehensive noise environment test system in China. It meets the laboratory standard requirements for environmental factors such as noise, temperature, and humidity.

[0018] 3. This invention adopts a sound-permeable and heat-insulating design to eliminate the interference effect of pneumatic loudspeaker loading noise on temperature and humidity environment, and solves the key problem of comprehensive testing technology for noise, vibration, temperature and humidity. Attached Figure Description

[0019] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0020] Figure 1 This is a schematic diagram of the overall structure of the noise, vibration, temperature and humidity integrated test system of the present invention;

[0021] Figure 2 This is a schematic diagram of the comprehensive test process for noise, vibration, temperature, and humidity of the present invention.

[0022] The components include: 1. Compressed air container; 2. Shut-off valve; 3.1 Electric regulating valve one; 3.2 Electric regulating valve two; 4.1 Pressure sensor one; 4.2 Pressure sensor two; 5.1 Pneumatic loudspeaker one; 5.2 Pneumatic loudspeaker two; 6.1 Nozzle one; 6.2 Nozzle two; 7. Small reverberation chamber; 8. Sound-permeable heat insulation device; 9. Silencing device; 10. Motor; 11. Fan; 12. Low-temperature shut-off valve; 13. Low-temperature solenoid valve; 14. Liquid nitrogen storage tank; 15. Refrigeration compressor; 16. Condenser; 17. Refrigeration expansion valve; 18. Evaporator; 19. Duct heater; 20. Dehumidification expansion valve; 21. Dehumidification evaporator; 22. Steam generator; 23. Steam electric regulating valve; 24. Temperature sensor; 25. Humidity sensor; 26. Electric vibration table; 27. Chamber seal; 28. Guide rail; 29. ​​Vibration sensor; 30. Transition head; 31. Microphone. Detailed Implementation

[0023] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0024] This embodiment provides a comprehensive environmental simulation test system for noise, vibration, temperature, and humidity, the schematic diagram of which is shown below. Figure 1As shown, it includes: compressed air container 1, shut-off valve 2, electric regulating valve 1 3-1, electric regulating valve 2 3-2, pressure sensor 1 4-1, pressure sensor 2 4-2, pneumatic loudspeaker 1 5-1, pneumatic loudspeaker 2 5-2, horn 1 6-1, horn 2 6-2, small reverberation chamber 7, sound-permeable heat insulation device 8, silencer 9, motor 10, fan 11, low-temperature shut-off valve 12, low-temperature solenoid valve 13, liquid nitrogen storage tank 14, refrigeration compressor 15, condenser 16, refrigeration expansion valve 17, evaporator 18, duct heater 19, dehumidification expansion valve 20, dehumidification evaporator 21, steam generator 22, steam electric regulating valve 23, temperature sensor 24, humidity sensor 25, electric vibration table 26, chamber seal 27, guide rail 28, vibration sensor 29, transition head 30, and microphone 31.

[0025] When the integrated environmental simulation test system provided by this invention is working, the compressed air container 1 stores high-pressure air. The shut-off valve 2 is opened to connect the air supply pipeline. Electric regulating valves 3-1 and 3-2, pressure sensors 4-1 and 4-2 are installed on the air supply branch pipelines respectively. The air supply pressure is fed back through pressure sensors 4-1 and 4-2, adjusting the opening of electric regulating valves 3-1 and 3-2 to control the air supply pressure to pneumatic speakers 5-1 and 5-2. Pneumatic speakers 5-1 and 5-2 generate sound, which is then transmitted to the reverberation chamber via horn tubes 6-1 and 6-2, exciting the air inside the reverberation chamber to generate pulsating pressure. Microphone 31 obtains the noise sound pressure level inside the small reverberation chamber and feeds it back to the noise controller, adjusting the drive signals of pneumatic speakers 5-1 and 5-2 to adjust the noise level inside the small reverberation chamber until the target value is reached. The sound-insulating and heat-insulating device 8 isolates the compressed air introduced by the horn type cylinder 6-1 and the horn type cylinder 6-2, and after the noise is reduced by the silencer device 9, it is discharged through the exhaust port.

[0026] During heating, motor 10 drives fan 11 to rotate, circulating the gas inside the mini reverberation chamber 7. Duct heater 19, evaporator 18, and dehumidifying evaporator 21 are placed inside the duct of the mini reverberation chamber 7. Duct heater 19 begins heating after being powered on. The circulating gas in the duct flows through duct heater 19, and after convective heat exchange, it heats the air inside the mini reverberation chamber 7. Temperature sensor 24 feeds back the temperature inside the mini reverberation chamber 7 to the controller to adjust the heating power of duct heater 19, thus achieving closed-loop temperature control of the mini reverberation chamber 7.

[0027] During cooling, the refrigeration compressor 15 is started first. The compressor compresses the gaseous refrigerant into a high-temperature, high-pressure liquid refrigerant, which is then sent to the condenser 16 for heat dissipation, becoming a medium-temperature, medium-pressure liquid refrigerant. The liquid refrigerant is throttled by the expansion valve 17 and enters the evaporator 18. The sudden increase in space and decrease in pressure causes the liquid refrigerant to vaporize, absorbing a large amount of heat. The evaporator cools down, and the circulating gas in the reverberation chamber flows through the evaporator, exchanging heat with it via convection. The evaporator absorbs the heat from the gas in the reverberation chamber, thus cooling the gas. When the temperature inside the small reverberation chamber reaches below zero degrees Celsius, the low-temperature shut-off valve 12 and the low-temperature solenoid valve 13 are opened, allowing liquid nitrogen from the liquid nitrogen storage tank 14 to be transported into the air duct of the small reverberation chamber 7. The vaporization of the liquid nitrogen absorbs the heat from the gas in the small reverberation chamber 7, further cooling the gas.

[0028] When humidity is applied, the steam electric regulating valve 23 is opened, sending saturated steam from the steam generator 22 into the air duct of the small reverberation chamber 7, increasing the humidity of the gas inside the chamber. The amount of humidification can be controlled by the steam electric regulating valve 23 to maintain a constant humidity level. When dehumidification is required, the dehumidification expansion valve 20 is opened, sending refrigerant into the dehumidification evaporator 21. The surface temperature of the dehumidification evaporator is lower than the condensation point of the humid air inside the chamber, causing water vapor to condense into water upon contact with the cold air, thus reducing the humidity level inside the chamber. The condensate is discharged through the reverberation chamber drain pipe.

[0029] The connection between the electric vibration table 26 and the small reverberation box 7 is sealed by the box seal 27. The transition head 30 is installed on the moving coil of the electric vibration table 26 and placed inside the small reverberation box 7. The vibration sensor 29 is installed on the surface of the transition head 30 to measure the vibration acceleration of the vibration table and transmit the vibration acceleration signal to the vibration controller. The vibration controller controls the output of the vibration power amplifier and adjusts the vibration level of the electric vibration table so that the vibration table completes the vibration test according to the vibration spectrum.

[0030] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A comprehensive environmental simulation test system for noise, vibration, temperature, and humidity, characterized in that, The system comprises: a test chamber, a vibration table, a noise simulation device, a temperature simulation device, and a humidity simulation device; The vibration table is placed below the test chamber. The temperature simulation device and humidity simulation device apply temperature and humidity loads to the convective gas inside the test chamber. The test piece is mounted on the extended table surface of the vibration table using clamps. The noise simulation device uses a high-power electric airflow loudspeaker as the sound source, which is connected to the side wall of the enclosure, and a sound-absorbing exhaust channel is set on the top of the enclosure. The test chamber is equipped with a sound-permeable insulation layer that divides the chamber into two areas: a noise loading zone and a temperature, humidity, and vibration loading zone. The area inside the test chamber, excluding the noise loading zone outside the sound-permeable insulation layer, is an effective comprehensive test zone. Various environmental stresses in the system can be applied individually or simultaneously.

2. The noise, vibration, temperature, and humidity integrated environmental simulation test system according to claim 1, characterized in that, The sound-permeable insulation layer enables the connection of the sound field and the isolation of the temperature field.

3. The noise, vibration, temperature, and humidity integrated environmental simulation test system according to claim 1, characterized in that, The test chamber is a reverberation chamber, which generates a diffuse sound field inside the chamber.

4. The noise, vibration, temperature, and humidity integrated environmental simulation test system according to claim 1, characterized in that, Microphones are placed inside the test chamber to control the sound field averaging.

5. The noise, vibration, temperature, and humidity integrated environmental simulation test system according to claim 4, characterized in that, The noise simulation device operates as follows: The noise controller transmits the required sound spectrum and magnitude drive signal to the power amplifier for amplification, driving the moving coil inside the electric airflow loudspeaker. At this time, high-pressure gas is sent into the electric airflow loudspeaker, and the airflow passes through the slit between the moving and stationary coils of the electric airflow loudspeaker, generating sound. Subsequently, the sound wave is transmitted to the test chamber through the horn tube, exciting the air inside the test chamber to generate pulsating pressure. The microphone collects the sound pressure signal inside the test chamber and feeds the signal back to the noise controller to correct the drive signal it sends, thereby realizing the closed-loop control of the noise simulation device, and ultimately ensuring that the sound pressure inside the test chamber meets the requirements.

6. The noise, vibration, temperature, and humidity integrated environmental simulation test system according to claim 5, characterized in that, After the gas driving the microphone enters the chamber, it is blocked by the sound-permeable insulation layer and cannot enter the temperature and humidity loading zone. It is then discharged to the outside of the chamber through the silencer exhaust channel.

7. The noise, vibration, temperature, and humidity integrated environmental simulation test system according to claim 1, characterized in that, The temperature simulation device includes a heating device and a cooling device, and can achieve closed-loop temperature control by feeding back to the controller through sensors.

8. The noise, vibration, temperature, and humidity integrated environmental simulation test system according to claim 7, characterized in that, The refrigeration device achieves gas cooling inside the test chamber through compressor refrigeration and liquid nitrogen-assisted refrigeration.

9. The noise, vibration, temperature, and humidity integrated environmental simulation test system according to claim 1, characterized in that, The humidity simulation device uses an electrically heated steam generator with pressure control to provide steam.

10. The noise, vibration, temperature, and humidity integrated environmental simulation test system according to claim 9, characterized in that, Precise humidity control is achieved through the humidification solenoid valve and dehumidification expansion valve in the humidity simulation device.

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