Technical measures to enhance the reliability of PCB equipment: scheme choice, circuit design, PCB design, structural design, component selection, production process and other aspects, specific measures are as follows:
(1) to simplify the design.
Design, in ensuring that equipment meet the technical, under the premise of performance indicators, should try to simplify the design, simplify the circuit and structure design, make each parts are the minimalist design. The world's popular modular design method is an effective measure to improve equipment reliability. Block function relatively single, the system is composed of modules, can reduce the complexity of the design, the design standardization and normalization. A large number of facts have proved that both at home and abroad, product design and modular design method should be adopted.
(2) the module and standard parts.
Modules and standard parts is proved after a large number of trials and widely used for high reliability products, thus can fully eliminate disadvantages of equipment and the hidden danger, also brought problems after replacement and repair. Adopts the module and standardized products can not only effectively improve the reliability of equipment, and can greatly shorten the development period, rapid modification for equipment and column packed with extremely favorable conditions.
(3) improve the level of integration.
With strong functions, high level of integration of a large, very large scale integrated circuit, try to reduce the number of components. The less components, produce less hidden danger point also. In this way, can not only improve the reliability of equipment, but. Can shorten the development, the development cycle.
(4) the derating design.
Derating design refers to the components under the condition of lower than the nominal stress work, is one of the effective methods to reduce the failure rate of components, therefore, is designed on the premise of ensure the technical performance indicators, when the working voltage range, the temperature characteristics of components, the electric characteristic parameters such as adopt derating use method, so as to reduce the failure rate of the components under various stress conditions.
Derating design, different components to consider the factors are not the same, have a plenty of voltage range, have a plenty of current size, have a plenty of temperature, have a plenty of frequency, have a plenty of vibration and so on. In general, high voltage, frequency and temperature characteristics of capacitance and resistance of power, current and frequency characteristic of inductance, diode, triode, SCR, operational amplifier, drives, gate junction current and junction temperature of the device or the fan out coefficient, the switch of power supply and main power source voltage/current resistance and heat resistance performance of cable, signal cable frequency characteristic, and the radiator, connectors, modules, power supply such as the use of the requirements for derating design.
(5) Choose the high quality device.
Components is a basic component unit of equipment, its quality will directly affect the reliability of the equipment. Military communication equipment should be above the industrial-grade products, preferably of military products, and strict in front of the computer screens, aging out early failure device.
(6) make full use of the software resources.
Due to the flexibility of software programming, in the design should make full use of the software resources. Software debugging methods and tools more, easy to locate fault and design problem, solve the cycle is relatively short. Make full use of the software resources is an important way to improve reliability.
(7) structure is reliable, the craft is mature and advanced.
Circuit, the structure design, should try to reduce the number of connectors, metallized hole, chips and circuit devices as far as possible with the method of directly on the PCB welding, choose surface-mount devices, USES surface-mount technology, in order to avoid poor contact, to ensure the reliability of the equipment.
(8) thermal design.
High temperature is one of the important factors that cause equipment performance and reliability to reduce, therefore thermal protection measures should be taken to control and lower the rise of temperature of the device to work, to ensure good heat dissipation, set to improve thermal reliability of the equipment.
Low temperature, can also cause equipment performance and reliability is reduced, some components can not work properly when the environment temperature is too low. So the equipment used in low temperature environment, also must carry on the low temperature test. Must be considered in the design of the temperature of the equipment working conditions and environment.
(9) electromagnetic compatibility design.
Equipment when working by many the interference of electromagnetic field, has someone for as well as natural. Military equipment, modern high-tech electronic fight, is a very important technological means local launch high-energy electromagnetic wave, to destroy the other components of equipment, so that the work equipment failure. Therefore should adopt effective anti interference measures such as shielding, filtering to prevent the interference of noise and interference of electromagnetic field on the equipment, to ensure reliable operation.
(10) seismic design.
Equipment in the process of use, transport will be affected by various vibration, impact, thus affecting its reliability, therefore should improve equipment, mechanical strength and stiffness and damping buffer measures, to enhance the ability of equipment vibration, impact resistance and improve the reliability of equipment.
(11) the fault indicating device.
Circuit design fault detection and fault alarm device, in order to find fault in time, thus shortening the troubleshooting time of equipment.
(12) simple operation and convenient maintenance.
The function of the equipment operation, maintenance is one of the main factors to ensure equipment reliability. Design, should try to use plug-in unit, module, at the same time, adopting modular, standardized structure and rapid disassembly structure, to facilitate operation and maintenance. It's proved that the device adopts modular structure can greatly simplify the operation, convenient maintenance.
