1. Foreword
Based on the rapid development of photovoltaic industry and the continuous increase of photovoltaic power stations, it is inevitable to continuously improve and enhance the product development cycle, cost control and reliability of photovoltaic modules. Therefore, for manufacturers at all levels of the supply chain, their product quality can only meet the requirements of IEC test standards, which is far behind the expectations of the market. Therefore, finding a test method and model that can not only shorten the product development cycle, but also reduce the comprehensive cost and improve the reliability of components has become an unavoidable proposition for manufacturers at all levels.
2. Environmental stresses experienced by components
3. Various important test items
4. Current IEC 61215 and IEC 61646 standard tests
10.13 wet heat test
10.13.1 purpose to determine the ability of components to withstand long-term moisture penetration
10.13.2 steps: the test shall be conducted according to the requirements of iec60068-2-3:
a) Pre preparation place components at room temperature in a climate chamber without pretreatment
b) Conditions apply the following conditions to the assembly: test temperature: 85 ° C ± 2 ° C, relative humidity: 85% ± 5%, test duration: 1000h.
5. Current IEC standard tests
85 ℃ and 85% damp heat aging tests are used in photovoltaic industry
● advantages: industry standard, IEC approval, effective database
● disadvantages: the test time is long, the inaccurate algorithm determines the degradation of the packaging, and the imprecise algorithm is limited by most materials
6. We need to speed up testing
Idea:
(1) Increase the temperature and humidity; Over 85 ℃, 85%rh
(2) Shorten test time
(3) Failure mechanism mode cannot be changed
7. Lessons learned from relevant material industries
In Japan, generally speaking, the semiconductor failure on the market is caused by humidity. (almost 40%)
8. Hast test standard
9. What is the acceleration factor?
Taking semiconductor anti plastic material mould as an example
① It has a life of more than 500 hours under test conditions of 85 ℃ at 85% RH
② It has a test condition of 121 ℃ @100%rh, and the service life is more than tens of hours. If the above conditions are met, it can be considered that the service life can be more than 10 years under the commonly used ambient temperature and relative humidity of 85%@30 ° C.
10. Calculation of fast life test time
It should be noted that:
1. The value of EA (ea=0.8ev) is the recommended value in gr-1221
2. the premise of this conversion is that the failure mechanism of the product in the two aging modes is the same
3. the basic assumption of this conversion is that the characteristics of the product under high stress conditions are consistent with those under normal temperature.
4. generally, we will consider their different aging mechanisms and adopt different test schemes for the products.
