Reliability testing, refers to the determination and verification of product reliability through testing. Research in a limited sample, time and cost of use, to identify product weaknesses. Reliability test is a general term for a variety of tests conducted to understand, evaluate, analyze and improve the reliability of the product.
Reliability test can be divided into environmental test, life test, special test and field use test.
Reliability environment test
The test includes more items, mainly: ① climatic conditions, such as temperature, humidity, air pressure, wind, snow, salt spray, corrosive gases, etc., ② mechanical conditions, such as vibration, shock, centrifugal, collision, drop, weightlessness, noise, shock waves, etc., ③ radiation conditions, such as solar radiation, nuclear radiation, etc..
Life test
Life test is an extremely important content of the reliability test, through this test, you can understand the life characteristics of the product work, the failure of the law, and calculate the product failure rate and average life and other reliability indicators. Product life test, according to the length of time can be divided into long-term life test and accelerated life test.
Special test
Special test is to use a special instrument to test and check the relay. This test is not only applied in the reliability test, but also used more in the reliability screening test. Such as x-ray inspection, infrared inspection, helium mass spectrometry leak detection, radioactive tracer leak detection.
On-site use test
The environmental conditions of the field test is the actual conditions of product use. The field test can be more samples, time can be longer. Through this test can obtain practical statistics for improving and enhancing product quality to provide a more accurate basis.
What are the reliability tests?
Reliability test methods and classification of electronic products
One, such as environmental conditions to be divided into a variety of stress conditions, including simulation tests and field tests;
Two, to test the project can be divided into environmental testing, life testing, accelerated testing and a variety of special tests;
Three, if the purpose of the test to be divided, it can be divided into Screening test, identification test and acceptance test;
Four, if the nature of the test to be divided into two categories of destructive test and non-destructive test.
The usual classification is the reliability test is summarized in five categories:
A. Environmental test B. Life test C. Screening test D. Field test E. Identification test
A. Environmental test
Some of the reliability of the monographs placed in the samples in the natural or artificially simulated storage, transportation and working environment test collectively referred to as the environmental test, is the assessment of the product in a variety of environmental conditions, and the test is the test of the environmental test. There are generally the following:
1, stability baking, that is, high-temperature storage test
Test purpose: to assess the impact of high-temperature storage of the product without the application of electrical stress. Serious defects in the product is in a non-equilibrium state, is an unstable state, from non-equilibrium to the equilibrium state of the transition process is both the process of inducing serious defects in the product failure, but also to promote the product from a non-stable state to a stable state of the transition process.
This transition is generally a physicochemical change, the rate of which follows the Arrhenius formula, increasing exponentially with temperature. The purpose of high temperature stress is to shorten the time of this change. So the experiment can also be regarded as a process to stabilize the product properties.
Test conditions: generally selected a constant temperature stress and holding time. Microcircuit temperature stress range of 75 ℃ to 400 ℃, the test time for more than 24h. Before and after the test sample should be in the standard test environment, both the temperature of 25 earth 10 ℃, air pressure of 86kPa ~ 100kPa environment for a certain period of time. In most cases, it is required to complete the endpoint test within a specified time after the test.
2, temperature cycling test
Test purpose: to assess the ability of the product to withstand a certain rate of change in temperature and the ability to withstand extreme high and low temperature environment. Is set for the product thermal and mechanical properties. When the material constituting the various components of the product thermal match is poor, or components of the internal stress is large, the temperature cycle test can trigger the product by the mechanical structure of the defects of the deterioration of the failure. Such as air leakage, internal lead breakage, chip cracks and so on.
Reliability testing includes what
Reliability testing is to assess the product in the specified life period, in the expected use, transportation or storage of all environments, to maintain the functional reliability of the activities carried out.
Reliability testing is generally conducted during the research and development and production phases of a product, and is a means of investigating, analyzing and evaluating the reliability of a product. The test results can provide a basis for failure analysis, study the corrective measures taken, and determine whether the product meets the target requirements.
China Tech Inspection has a professional testing qualification, can provide a number of reliability test program services: environmental reliability testing, electromagnetic compatibility EMC testing, and IP protection level testing. Common reliability testing services include: vibration, shock, drop, high and low temperature, salt spray test, as well as mold, light aging and other experiments, issued by the nationally recognized CMA test report.
What is included in the environmental reliability test
Environmental testing as a type of reliability test equipment has developed into a method of predicting how the environment in which a product is used affects its performance and function. That is to say, before a product is put on the market, environmental testing is used to assess the extent to which the environment affects the product; when the product's functionality is affected, environmental testing is used to identify the cause and to take measures to protect the product from environmental influences in order to maintain the product's reliability. These tests have far outlived their original purpose. They are now used in a wide range of applications including material and product development, a variety of different inspections during the manufacturing process, pre-shipment inspections and post-shipment quality control.
Environmental Reliability Test Items
Low Temperature Storage Test, High Temperature Storage Test, Temperature Cycling/Impact Test, Low Temperature Durability Test, High Temperature Durability Test, Moisture and Heat Test, Salt Spray Corrosion Test, Vibration Test, Impact Test, Durability Test, Simulated Packaging and Transportation Test, and more.
Environmental Reliability Test Center
China Tech Inspection
Conducts environmental reliability tests, with a team to test your products, and can carry out high temperature storage tests, temperature cycling tests, thermal shock tests, low air pressure tests, humidity resistance tests, salt spray tests and so on.
Environmental reliability test categories
Climatic environment test, mechanical environment test and comprehensive environment test
Climatic environment test includes temperature, humidity and pressure and other environmental stress test, while the mechanical environment test includes shock and vibration will be uanj stress test, comprehensive environment test is a combination of climatic and mechanical environmental factors, the use of environmental test equipment for the test is not possible. Tests using environmental test equipment can not be completely accurate reproduction of the product environment and simulate all the environmental factors, it is important to understand the limitations of environmental testing. An environmental test consisting of a single factor is called a simple environmental test.
What is a reliability test
The test conducted to evaluate and analyze the reliability of electronic products is called a reliability test. The purpose of the test is usually the following aspects: 1. In the development stage to expose the defects of various aspects of the trial product, evaluation of the reliability of the product to meet the predetermined targets; 2. Production stage to monitor the production process to provide information; 3. Reliability of the final product identification or acceptance; 4. Exposure and analysis of the product in different environments and stress conditions of the failure of the law and the relevant failure modes and failure mechanisms; 5. Improve the reliability of the product, develop and improve the reliability test program for the user to select products to provide a basis. For different products, in order to achieve different purposes, you can choose different reliability test methods. Reliability test has a variety of classification methods. 1. such as environmental conditions to divide, can be divided into a variety of stress conditions, including simulation tests and field tests; 2. to test the division of the project, can be divided into environmental tests, life tests, accelerated tests and a variety of special tests; 3. if the purpose of the test to be divided, can be divided into screening tests, qualification tests and acceptance tests; 4. if the nature of the test to be divided, it can be divided into Destructive test and non-destructive test of two categories. 5. But the usual customary classification, it is summarized in five categories: A. Environmental test B. Life test C. Screening test D. Field test E. Identification test 1. Environmental test is to assess the adaptability of the product in a variety of environmental conditions, is to evaluate the reliability of the product is one of the important test methods. 2. Methods, this method can be simulated in the laboratory to carry out a variety of conditions of use. Life test is one of the most important and basic items in the reliability test, it is the product in a specific test conditions to examine its failure over time change rule. Through the life test, you can understand the product's life characteristics, failure pattern, failure rate, average life and in the life test process may appear in a variety of failure modes. If combined with failure analysis, can further clarify the main failure mechanism leading to product failure, as the basis for reliability design, reliability prediction, improve the quality of new products and determine a reasonable screening, routine test conditions. If in order to shorten the test time can not change the failure mechanism under the conditions of increasing the stress of the test, which is accelerated life test. Through the life test can evaluate the reliability level of the product, and through the quality feedback to improve the reliability level of new products.3. Screening test is a kind of non-destructive test for the full inspection of the product. Its purpose is to select products with certain characteristics or reject the early failure of the product, in order to improve the reliability of the product. Products in the manufacturing process, due to material defects, or due to the process out of control, so that part of the product so-called early defects or failures, these defects or failures if you can be eliminated as early as possible, you can ensure that the actual use of the product reliability level. Reliability screening test is characterized by: A. This test is not sampling, but 100% test; B. The test can improve the total reliability level of qualified products, but can not improve the inherent reliability of the product, that is, can not improve the life of each product; C. Can not simply screen the elimination rate of the screening effect of the evaluation. Elimination rate is high, it may be the product itself, design, components, technology and other aspects of the existence of serious defects, but it may also be screening stress intensity is too high. Elimination rate is low, there may be fewer defects in the product, but it may also be the intensity of the screening stress and test time is not enough to cause. Usually screen the elimination rate Q and screening effect β value to evaluate the advantages and disadvantages of the screening method: a reasonable screening method should be β value is large, while the Q value is moderate. The above tests are conducted by simulating the field conditions. Simulation test due to the limitations of the equipment conditions, often only a single stress on the product, sometimes can also be applied to the double stress, which is very different from the actual use of environmental conditions, and thus failed to truthfully and comprehensively expose the quality of the product. Field use test is different, because it is carried out in the use of the scene, so it can most truly reflect the reliability of the product, the data obtained for the reliability of the product prediction, design and guarantee has a high value. For the development of reliability test program, verification of reliability test methods and evaluation of test accuracy, the role of the field test is even greater. The qualification test is a test done to evaluate the reliability level of a product. It is based on sampling theory to develop a sampling program.
What are the common categories of reliability tests
What are the types of reliability tests?
It is slightly different for each industry.
For heating equipment, similar to the following:
There are six major types of reliability tests. Laboratory thermostats and other equipment reliability test types, according to the test location can be divided into on-site reliability test and laboratory simulation reliability test. According to the purpose of the test can be divided into reliability determination test, reliability identification test, reliability acceptance test, success rate test, full reliability test and reliability growth test. Among them, the identification test, acceptance test, success rate test, the whole number of tests can be collectively referred to as reliability verification test. The so-called verification test, is to determine whether the product reliability characteristics of the amount of the required level of test.
1. Reliability test
The test is called reliability test in order to determine the value of the reliability characteristics of the equipment. This is a kind of equipment in the absence of quantitative provisions of the reliability requirements, the need to estimate the level of reliability of a piece of equipment when the test is carried out.
2. Reliability qualification test
In order to verify the design of the equipment can be in the specified environmental conditions, to meet the specified performance and reliability requirements of the test is called the reliability qualification test. The test should be conducted on a representative product. The results of the test as a judgment on whether the equipment can meet the requirements of the reliability indicators, can be one of the basis for stereotypes. Reliability identification test is applicable to the design of finalization, production finalization, the main design or process changes after the identification.
3. Reliability acceptance test
In order to determine the finalization of the mass production of equipment can meet the specified conditions in the specified performance and reliability requirements of the test is called reliability acceptance test. Acceptance test is not necessarily carried out in each batch, generally in the production and use of the party **** with the agreed time and batch.
4. Success rate test
When the reliability of the equipment is characterized by the success rate, in order to verify the equipment in the specified conditions, the number of tests or the probability of success of the number of equipment to meet the specified reliability characteristics of the test is called the success rate test.
5. Full reliability acceptance test
When it is specified that each piece of equipment to carry out reliability acceptance test is used. This test can replace the sampling acceptance test.
6. Reliability growth test
By taking corrective measures to systematically and permanently eliminate the failure mechanism, so that the reliability of the equipment to obtain a real increase in the test, called reliability growth test. It is not to verify that a test program can be passed, but through the test to expose the problems that exist in the equipment, failure analysis, to take improvement measures and retesting, so that the reliability of the equipment has grown to meet or exceed the intended reliability requirements of the equipment. Reliability growth test in the equipment development stage.
------------------------------
Electronic industry:
Reliability test definition, purpose, classification
Author:unknown;Published:2015-12-910:38:54;Source:Internet Click:1896
Reliability test Refers to: the ability of the product to fulfill the specified function under the specified conditions and within the specified time. Products in the design, application process, constantly subjected to their own and external climatic environment and mechanical environment, and still need to be able to work properly, which requires test equipment to verify its verification, this verification is basically divided into R & D test, trial production test, mass production sampling three parts.
Definition
reliabilitytest
To understand, evaluate, analyze, and improve the reliability of the product and the general term for a variety of tests.
Folding Editorial Purpose
The purpose of the reliability test is: to discover the various defects of the product in design, material and process, etc., after analysis and improvement, so that the product reliability gradually grows, and ultimately reach a predetermined level of reliability; to improve the product's operational readiness, improve mission success, reduce maintenance and security costs to provide information; to confirm whether it is in line with the specified quantitative reliability requirements. Reliability quantitative requirements.
Folding Editorial Classification
Reliability test can be a test in the laboratory, or on-site test. According to the purpose of the test can be divided into two categories: engineering tests and statistical tests.
The purpose of the engineering test is to expose the reliability weaknesses of the product and take corrective measures to eliminate them. This test is carried out by the contractor to develop the prototype as a test product.
The purpose of statistical tests is to verify that the reliability of the product meets the specified quantitative requirements at a certain level of confidence. Statistical tests are generally recognized by the third-party laboratory responsible for the completion of the test unit must be approved by the ordering party in advance. Reliability tests should be combined with product performance tests, environmental adaptability tests, etc. to carry out as far as possible.
The current application of highly accelerated life test, highly accelerated stress screening and reliability enhancement test also belongs to the category of reliability test.
Reliability Classification
Reliability Classification
Folding Editorial Test Purpose
To evaluate and analyze the reliability of electronic products and the test is called reliability test. The purpose of the test is usually the following:
1. In the development stage to expose the defects of the trial product in various aspects, to evaluate the reliability of the product to meet the predetermined targets;
2. The production stage to provide information for the monitoring of the production process;
3. Reliability appraisal of finalized products or acceptance;
4. Exposure and analysis of product failure under different environmental and stress conditions Exposure and analysis of product failure in different environments and stress conditions and related failure modes and failure mechanisms;
5. For the improvement of product reliability, development and improvement of reliability test program, to provide the basis for the user selection of products.
For different products, in order to achieve different purposes, you can choose different reliability test methods.
Folding editorial classification method
1. such as environmental conditions to divide, can be divided into including a variety of stress conditions under the simulation test and the field test;
2. to test the division of the project can be divided into environmental testing, life test, accelerated test and a variety of special tests;
3. if the purpose of the test to be divided into the screening test, the qualification test and acceptance test;
4. the test is divided into a number of different tests, Identification test and acceptance test;
4. According to the nature of the test to be divided into two categories of destructive tests and non-destructive tests.
5. But usually the usual classification, it is summarized into five categories:
A. Environmental tests
B. Life tests
C. Screening tests
D. Field use tests
E. Accreditation tests
Folding Edit this section of the test items
Reliability tests are to ensure that the product within a specified period of life. The product maintains functional reliability over a specified life span in all environments such as intended use, transportation, or storage. It is to expose the product to natural or artificial environmental conditions to withstand its role, in order to evaluate the performance of the product in the actual use, transportation and storage of environmental conditions, and analyze and study the extent of the impact of environmental factors and their role in the mechanism. Through the use of a variety of environmental testing equipment to simulate the climate environment of high temperature, low temperature, high temperature and high humidity and temperature changes, accelerate the reaction of the product in the use of the environment, to verify whether it reaches the quality objectives expected in the research and development, design, manufacturing, so as to assess the product as a whole, in order to determine the reliability of the product life. One pass testing laboratory will reliability test can be divided into mechanical and environmental two blocks. Reliability test items are as follows:
No.
Test Items
Test Scope
1
VibrationTest
Horizontal and vertical vertical vibration vibration, Sine, Random, Sine + Random Sine + Random. Sine+Random
2
MechanicalShockTest
5000m/s2
3
CollisionTest
250kg, 50m/s2~300m/s2
3
CrashTest
The test is conducted by the Vibration Test Center of the University of California, Berkeley, which is the first of its kind in the world to be conducted by a company that is a member of the Vibration Test Center. s2
4
PackingDrop
DropGesture:Angle,Corner,Surface
5
SimulationTransportation
Tertiary HighwayTertiaryHignway:35km/hMaxLoad:1500kg
6
CompressiveStrength
MaximumPressure:5ton
7
IPRange
Dustproof
IP1Y~IP6Y
Waterproof
IPX1~IPX8
8
StackTest
MaxLoad:5 ton
9
Temperature/Humidity/Vibration Temp./Humidity/VibrationComprehensiveTest
Temperature:-70℃~150℃,Humidity:25~98%RH,TemperatureChangeRate:15℃/minMax.Frequency:1~2000Hz,Acceleration. Acceleration:0~60gn, Displacementmax:50.8mm
10
Salt-fogTest
Neutral Salt Spray NSS, Acetate Spray AASS, Copper Accelerated Acetate Spray CASS
11
GasCorrosion
Gas CorrosionGasCorrosion
SO2/H2S/CO2
12
Constant Temperature and HumidityConstant Temp Hum.
20℃~95℃, 5~98%RH
13
Cold and Hot ShockThermalShock
- 65℃~150℃
14
UV Aging UVAging
UVA340,UVA351,UVB313
15
Fast Temperature Change ThermalCycling
70℃~150℃,25~98%RH,_20℃/min< /p>
Expand
Collapse Edit Specifics
The test to evaluate and analyze the life characteristics of a product is called a life test. For most electronic products, life is the single most important reliability characteristic quantity. Therefore, the reliability test often refers to the life test. Life test can be divided into non-working state of the storage life test and working state of the working life test two categories. In order to shorten the test cycle, reduce the number of samples and test costs, accelerated life tests are often used. Under the premise of not changing the failure mechanism of the product and adding new failure factors, the test stress is increased to accelerate the failure process of the product. According to the different ways of applying stress in the test can be divided into: ① in the test process stress remains constant constant stress accelerated life test; ② test process stress step-by-step step-by-step increase in the accelerated life test; ③ test process stress continuous increase in the accelerated life of the sequential stress test.
Since the life test is more time-consuming, usually do not wait for all the samples to be subjected to the end of the failure, that is, most of the life test is a truncated test. According to the test cut off the end of the test sample failure and replacement, life test can be divided into four kinds: ① no replacement timed cut off test; ② replacement timed cut off test; ③ no replacement of the fixed number of cut off test; ④ replacement of the fixed number of cut off test. In the life test of electronic products, the most commonly used life distribution for the exponential distribution, Weibull distribution and lognormal distribution. The most commonly used methods of statistical analysis of life test data are probabilistic paper graphical method, maximum likelihood estimation method, optimal linear unbiased estimation method, optimal linear invariant estimation method and so on.
The so-called screening, is to try to remove in the materials, components, devices, equipment, systems and other aspects of the potential adverse factors and defects, and the excellent product selection. The use of applied stress or other means to the finished product in the potential early failure of the product removed from the test is called reliability screening. Applied stress can be thermal stress, electrical stress, mechanical stress or a combination of several stresses, screening the size of the stress and the time of action of the selection principle is: ① the main failure mechanism for the product; ② the stress used for good products should not be destructive, and for defective products should be able to defects are quickly exposed; ③ according to the use of the cost of the product batch sizes and test equipment, etc., and other conditions, and strive for the best economic results; ③ according to the use of the cost of product batch sizes and test equipment, and other conditions, and unity of opinion The best economic results; ④ full investigation, data collection, grasp the distribution of product failure and failure mechanism, in order to determine a reasonable screening program. The most common screening methods are: ① visual inspection; ② electrical performance testing; ③ seal leakage detection; ④ environmental stress screening; ⑤ life screening.
Folding editorial hardware test
Also known as the product reliability assessment, the product in the specified conditions, in the specified time to complete the specified function of the ability. Products in the design, application process, constantly subjected to their own and external climatic environment and mechanical environment, and still need to be able to work properly, which requires test equipment to verify its verification, this verification is basically divided into R & D tests, pilot production tests, mass production sampling three parts. Reliability tests include: aging test, temperature and humidity test, gas corrosion test, mechanical vibration test, mechanical impact test, collision test and drop test, dust and waterproof test and packaging pressure test and many other environmental reliability tests.