Objectives of environmental stress analysis
The purpose of environmental stress testing is to find and eliminate early product failure, bring them into the process of random failure when they leave the factory, and hand them over to users with a level of confidence.
Principles of Environmental Stress Assessment
Environmental stress testing is a process that makes internal faults quickly and errors by applying reasonable environmental stress and electrical stress to electronic equipment, so that people can find and eliminate them.
Analysis for environmental protection is a technical way of creating and creating infrastructure. The protective effect depends on the applied environmental stress, the level of electrical stress and the capacity of the detection device. The amount of pressure applied determines whether the potential faults can be increased and the faults can be increased within a given period of time. The detection power determines whether the updated faults and faults can be found quickly through the pressure for troubleshooting. Therefore, environmental stress analysis can be seen as an extension of the product management process and analysis process. 2 arrangements of dots
General description
The loss of the specific function of the product is called failure. Remedial products are often referred to as stains. For this reason, any quality feature that does not meet the specified technical standards is a defect.
Damage to many electronic devices is called damage. Accidental failure is believed to be an unplanned failure, which results in severe failure of equipment and parts; while failure-type failure is caused by equipment defects, equipment damage, assembly process errors, and design defects, the equipment damage itself is caused by defects such as design, process and materials, and design errors are includes circuit design errors, design defects, system design errors, etc.
Classification of optical defects of electronic components
In terms of effects and consequences, faults are divided into lethal damage, heavy faults and light faults: from a visual point of view, the main types of fault systems include: solder, unsoldered connections, excess wires and cables, prevention of short-circuit opportunities. , contacts, circuit boards, manufacturing and installation of parts, components, winding, marking, etc., many of them can create fatal faults or heavy faults, electrical faults are common.
Fatal defects refer to defects that can cause injury or insecurity to users, such as the use, maintenance, transportation and storage of equipment or that can impair the performance of some important equipment. (E.g. ships, tanks, artillery) Aircraft, missiles, etc.).
Major faults refer to faults that can cause failure or significantly reduce the functionality of the equipment, but are not fatal faults.
Defects refer to defects that do not cause serious defects, but will reduce the performance of the equipment or do not meet the specified technical standards, and have little effect on the use or operation of the equipment.
Visual defects refer to defects that can be seen directly from the human body or judged by simple tools and characteristics of the equipment.
The quality inspector of the factory can find the visible defects and submit them to the relevant departments for elimination. Only invisible defects can be found through environmental stress testing or other methods, otherwise the reliability of the product will be affected.
Environmental Concerns Monitoring System Design Principles
The design principle of the environmental monitoring plan is to allow the pressure test to detect possible design errors, manufacturing errors, and equipment errors: the applied pressure does not modify the life profile, the activity profile, and the environmental profile that are specified. Products during the test, different types of work specific to the design will be simulated.
Decide on regular inspections or quantitative inspections according to the situation and need: design the inspection system according to the different levels and characteristics of the product.
Review during development
During the development stage, the first research is done as a research process based on experience. Its main functions are as follows: on the one hand, it is used to collect information such as the type and amount of possible product damage and the impact of the inspection method; On the other hand, regular testing is done before reliability growth and technology development research, which can save time and money. At the same time, it helps to create a mature test system and rapid development.
Continuous research at the development stage should collect data for quantitative analysis at the production level, prepare quantitative analysis, and design a list for quantitative analysis.
Check during production
Monitoring during production is key to implementing quantitative research strategies designed at the development stage. By analysing the recorded failure rate and the cost of the plan, a process is proposed for reorganizing the research and planning process. Update or modify the quantitative selection strategy in reference to qualitative quantitative selection experience data from products with design and maturity. This knowledge includes:
Types of equipment and materials with high failure rates: suppliers with high failure rates.
Receipt of equipment analysis, analysis and data analysis: records of previous analysis and tests.
Confidence growth records: other test records.
The effect of environmental stress on defects
Environmental and regional concerns are the main factors influencing the development of defects in defects. Any defect that turns into a defect must have a certain pressure resistance. After some time, it is only when the product is under environmental pressure equal to or greater than the threshold that some defects can become defects: in some light and environment, most defects will not become defects. Therefore, the purpose of the research can only be achieved by choosing a restriction that can reveal some defects such as research conditions.
Conclusion
Environmental pressure analysis is the technical development and production process of the whole machine. Each product must be completed. In order to save resources and time, we should try to choose pressure conditions with high performance and assembly quality at low cost. Random vibration equipment and thermal cycling equipment are important, and should be installed by the manufacturer as soon as possible. Before it is fixed, it can be applied to areas close to these conditions. At this point, it is important to select and review the assembly level.
Developing an environmental stress assessment system is a major undertaking. It is important to know the history and information of the current situation of the production of products, processes and materials, and collect the necessary data: when choosing the analysis of environmental pressure or quantity of materials environmental hazards, and from the level of the research assembly that will be chosen, some risks will be considered. Therefore, systems engineering techniques must be applied to achieve comprehensive agreement around product reliability requirements.
Environmental stress analysis and reliability growth testing are typical of reliability engineering testing. They have a common goal and their own identity. They can complement each other but they cannot replace each other. Environmental testing can be used to grow more reliable, to get full access to the results of environmental testing and improve test performance.
