This standard specifies a test method for evaluating the resistance of small electrical and electronic products, mainly non-airtight parts, to moisture and heat degradation effects in an accelerated manner. This test is not suitable for evaluating external effects such as corrosion and deformation. GB/T 2423.50-1999 Environmental testing for electrical and electronic products Part 2: Test method Test Cy: Steady moisture and heat Mainly used for accelerated testing of components GB/T2423.50-1999 Standard download decompression password: www.bzxz.net

GB/T 2423. 50-- 1999
This standard is equivalent to the International Electrotechnical Commission standard IEC68-2-67: 1995 "Environmental test Cy: Steady damp heat is mainly used for accelerated testing of components". Appendix A and Appendix B of this standard are both indicative appendices. This standard was proposed by the State Machinery Industry Bureau. Part 2: Test methods
This standard is under the jurisdiction of the National Technical Committee for Environmental Conditions and Environmental Testing of Electrical and Electronic Products. The drafting unit of this standard is Guangzhou Electric Science Research Institute. The main drafters of this standard are Zhang Qiangying and Zhang Chi. 504
GB/T2423.50--1999
IEC Foreword
1) IEC (International Electrotechnical Commission) is a world standardization organization composed of all national electrotechnical committees (IEC National Committees). The purpose of IEC is to promote international cooperation on standardization issues in the field of electrical and electronic engineering. To this end, IEC, in addition to other activities, also publishes international standards. International Standards are entrusted to technical committees for preparation. Any national committee interested in the subject of the standard may participate in the drafting of the standard. International organizations, governmental and non-governmental organizations in liaison with the IEC may also participate in this work. The IEC works closely with the International Organization for Standardization (ISO) under the terms of an agreement between the two. 2) Since the technical committees are represented by all interested national committees, the formal decisions or agreements of the IEC on technical issues express, as far as possible, the international consensus on the issues involved. 3) The documents prepared are accepted by the national committees in the form of recommendations for international use and are published in the form of standards, technical reports or guidelines.
4) In order to promote international uniformity, the IEC national committees commit to faithfully adopt IFEC international standards in their national and local standards to the greatest extent possible. Any differences between IEC standards and corresponding national or local standards shall be clearly stated in the latter. 5) The IEC has not established any procedures for the recognition of marks. Therefore, no responsibility is assumed for any equipment claiming to comply with IEC standards. 6) It should be noted that some parts of this international standard may be patented and the IEC is not responsible for identifying any or all of these patented items. The international standard IEC68-2-67 was prepared by Technical Committee 50 (Environmental Testing) of the IEC, Subcommittee 50B (Climatic Testing). bzxZ.net
The text of this standard is based on the following document: Final Draft International Standard (FDIS)
50B/360/FDIS
Full voting information for the approval of this standard can be found in the voting report in the table above. According to IEC Guide 104, this standard has the status of a basic safety publication. Under the general title of environmental testing, IEC68 consists of the following parts: Part 1: General
Part 2: Tests
- Part 3: Background information
Part 4: Information for standard developers-Summary of tests Part 5: Guidelines for the preparation of test methods
Appendix A and Appendix B are for reference only.
Voting report
50B/373/RVD
National Standard of the People's Republic of China
Environmental testing for electric and electronic products
Part 2:Tests--Test Cy:Damp heat ,steady state . acceleratedtest primarily intended for components1Scope
GB/T2423.50---1999
idt IEC 68-2-67: 1995
This standard specifies a test method for evaluating the resistance of small electrical and electronic products, mainly non-hermetic components, to the effects of damp heat degradation in an accelerated manner.
This test is not suitable for evaluating external effects such as corrosion and deformation. 2 Overview
In this test, the sample is subjected to high unsaturated hot and humid vapor pressure for a long time. Usually bias pressure is applied
This test provides several preferred test durations at 85% relative humidity and 85°C. For plastic sealed components, the degradation is caused by the absorption of water vapor by the plastic and the penetration of water vapor along the lead-out terminals. 3 Description of the test apparatus
3.1 Test chamber
The test chamber shall be designed and manufactured as follows:
a) It can produce the temperature and relative humidity conditions given in Table 1 and maintain them for at least 2000 hours without interruption; b) During the test, it shall provide controlled temperature and humidity conditions and be able to increase and decrease the temperature according to the specified slope; c) The temperature and humidity in the test chamber shall be monitored by a sensor device placed in the working space or (and) other areas that can give the same results;
d) The working space shall be continuously drained and cannot be reused; e) Condensation water is not allowed to fall on the test sample; f) The structural material of the chamber wall shall not cause obvious corrosion of the test sample and reduce the quality of the humidification water (see Appendix B1). The temperature tolerance of ±2C takes into account the absolute error of measurement, the change in temperature between any two points in the working space, and the temperature fluctuation at any point.
In order to maintain the relative humidity within the specified tolerance of 5%, the difference (at any moment) between any two points in the working space must be kept within a smaller range.
If such a temperature difference exceeds 1.5, the specified humidity tolerance will be exceeded. Therefore, short-term temperature fluctuations caused by periodic heating of the test chamber heater must also be limited to similar values. State Administration of Quality and Technical Supervision approved 506 on October 10, 1999
2000-05-01 implementation
The test sample should not seriously hinder the air flow. GB/T 2423. 50 -1999
Condensation is not allowed to form on the sample at any time during the test. 3.2 Humidification water
Distilled water or deionized water should be used. The water should have a resistivity of not less than 0.5MQ/cm at 23C. The pH value should be between 6.0 and 7.2.
Before filling the humidifier with water, the internal parts of the test chamber should be cleaned. The cleaning guidelines are given in Appendix B3. After each test, all water in the humidifier and the test chamber should be removed. 4 Severity level
In this standard, the test severity level is determined by the test duration. Unless otherwise specified, the relevant specifications should select the severity level from the duration given in Table 1.
Table 1 Severity level
Relative humidity
1) Temperature tolerance: 2°C in the working space of the test chamber. 2) Relative humidity tolerance: ±5%.
3) Duration tolerance: *5%.
4) Definition of duration: See 7.4.2. 168
Duration 34),h
Note: It is not recommended to restart a test, but if the test sample is required to withstand a test of more than 2000)h, it should be restarted according to the requirements of Chapter 7. The test should be restarted within 96h after the end of the cooling stage of the previous test. Unless otherwise specified in the relevant specifications, the test samples should be kept under the standard atmospheric conditions used for inspection or testing during the interval between tests. 5 Pretreatment
Pretreatment may be required by the relevant specifications.
6 Initial inspection
The test samples must be visually inspected, dimensional measured and functionally tested in accordance with the provisions of the relevant specifications. 7 Conditioning test
7.1 Place the test samples under the test room temperature, air pressure and humidity conditions, and then place the test samples in the working space of the test chamber. 7.2 The test samples should not be subjected to radiant heat from the heater and the walls of the test chamber. If the relevant specification requires the use of special mounting devices, the thermal conductivity and heat capacity of the mounting devices shall be low enough to make the test sample actually insulated.
The mounting devices and the materials of the mounting devices should be carefully selected to minimize the effects of contamination and to minimize deterioration due to corrosion and other causes (see Appendix B1).
7.3 If required by the relevant specification, a bias voltage shall be applied to the test sample during the test. Guidance on the application of bias voltage is given in Appendix B2. The bias voltage (or bias voltage cycle) shall be applied to the test sample when the temperature and relative humidity have reached a stable state and shall be continuously applied until the test sample is in a recovery condition.
7.4 Test cycle
7.4.1 Raise the temperature and relative humidity of the test chamber to the appropriate limits. During the test, no condensation is allowed on the test sample. The temperature and humidity shall be stable within 3 hours.
GB/T 2423.50--1999
7.4.2 The temperature and relative humidity shall be maintained within the specified range for the duration specified in the relevant specifications. The test duration shall be calculated from the moment the test conditions reach stability. 7.4.3 After the specified test time, the temperature and relative humidity of the test chamber shall be restored to the standard atmospheric conditions for inspection and testing within 1h to 4h.
During this period, the temperature and relative humidity shall not exceed the specified values ​​and the bias voltage shall be maintained. 7.4.4 After the cooling stage is over, the sample shall enter the recovery procedure. 8 Intermediate testing
The relevant specifications may require electrical or mechanical performance tests during the test. If intermediate testing is required, the relevant specifications should specify the test items and where these tests are performed, but these tests should not cause any changes in the test conditions
During the test, it is not allowed to move the test sample outside the test chamber for testing after recovery 9 Recovery
After the test, the test sample shall be recovered. Unless otherwise specified in the relevant specifications, the recovery should be carried out for 2h to 24h under the standard atmospheric conditions for inspection and testing.
10 Final inspection
The test samples should be inspected for appearance, measured for dimensions and tested for functions in accordance with the relevant specifications. 11 Information to be given in relevant specifications
When the relevant specifications adopt this test method, the following details should be given, especially the items with (*): Clause number
a) Test severity level (duration)\b) Atmospheric conditions between tests (if not standard atmospheric conditions)c) Pretreatment"
d) Initial test
e) Special installation device
f) Bias
g) Intermediate test
h) Recovery"
1) Final test*
GB/T 2423.50--1999
Appendix A
(Suggestive Appendix)
Physical meaning of the test
A1 The accelerated penetration of water vapor into the test sample is the most important physical factor in the accelerated damp heat test. The acceleration effect is caused by the difference in water vapor partial pressure between the inside of the non-airtight test sample and the test environment. A2 This test is mainly used for accelerated corrosion of aluminum in integrated circuits and other plastic encapsulated semiconductor devices. When considering the use of this test for other products, it is important to determine the failure mode and select the appropriate degradation process and test severity level according to each failure mode. Appendix B
(Indicative Appendix)
Test Equipment and Management
B1 Selection of Materials
Careful selection of materials used in the test chamber will greatly reduce the release of pollutants and degradation caused by corrosion and other causes, which are produced under the temperature and humidity combination conditions specified in this test. Suitable materials are: stainless steel, glass, ceramics and other corrosion-resistant materials.
B2 Bias
Bias is defined as the voltage applied by the test itself to enhance the humidity effect. It is not necessarily related to the normal function of the test sample. The bias should be applied according to the following guidelines and are given in descending order of importance as follows: a) The increase in temperature at each specified point on the surface of the sample should be less than 2°C relative to the nominal temperature of the working space. b) When selecting the bias voltage, care should be taken to promote hydrolysis while limiting the self-heating of the test specimen. This is because self-heating affects the penetration and absorption of water. When it is impossible to prevent significant self-heating by applying a continuous bias voltage, it is recommended to apply the bias voltage intermittently. Unless otherwise specified, the order of applying the bias voltage is to stop the bias voltage for 3 hours and then apply the bias voltage for 1 hour. c) Precautions should be taken to limit the energy loss caused by fault conditions. Note: Applying a bias voltage to the test specimen under conditions of constant relative humidity can enhance various effects induced by water vapor. However, the bias voltage causes power dissipation, which has the opposite effect to the purpose of the test. This is because the increase in local temperature will reduce the relative humidity at critical locations. B3 Cleaning
The test chamber and all mounting equipment installed in the chamber (test specimen rack, etc.) must be cleaned. The test chamber and internal fixtures can be cleaned with a soft brush dipped in a diluted laboratory detergent and then rinsed with distilled or deionized water. It is recommended that the test chamber be cleaned before each test.
It is recommended that gloves and masks should be worn during cleaning to prevent contamination of the test chamber and internal fixtures, and that the test equipment be used in a clean location. Unless otherwise specified, the test samples should be tested in the received state and under normal operation. Testing of test samples that have been specially cleaned before testing may not show the effects produced during use. 509
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