“Rainy season” is a seasonal occurrence that takes place at different times of the spring and summer in different parts of China. Rainy season starts in the south and moves north as the months go by. South Chinawill be rainier earlier in the spring from April-May. The plum rains,梅雨 meiyu, or “may yoo” in Mandarin, nicknamed for the season when the fruit ripens, hit Nanjing, Suzhou, Wuxi and other main cities in Jiangsu Province in eastern China.
Rainy season, as the name implies, is usually several weeks of rainy weather where you can count on the weather being wet. While in some parts of China, rainfall will be higher at certain times of the year, it does not have an official rainy season.
Rainy season can be mild with just overcast skies and light sprinkles or it can feel like it’s raining torrential downpours on a daily basis. There’s no telling how it will be and on your weather app, you’ll just see day after day of cloudy skies and thunderstorm icons.
On rainy days the humidity goes to 90%, many stuffs like IC, semiconductors, precision instruments, electronics, chips, optical films, lens have mold in the air while the air mold spores cannot be detected by the natural eye.
The main parts of LED display screens like LED lights and IC are allergic to humidity. Screens don’t work or IC quality can be influenced when the parts become wet.Electronics have to be stored in a place where humidity is well controlled in wet season to keep their quality.
Tips to remove moisture from LED components
1Moisture-proof keyword: the place to be stored
Moisture proof and anti- static aluminium package are used in LED products. Stress and puncture should be avoid when delivering. If the LED package bags already leaks or breaks, please stop use and take optical-electrical performance tests and high-temperature moisture-removing before use again.
If the humidity-proof bag has not been opened, it is better keep the components in YUNBOSHI electric dehumidifiers where the humidity is under 30℃／60RH.
It’s suitable to store LED electronics in YUNBOSHI dehumidifier. Kunshan Yunboshi Technology Electronics Co.,Ltd. is a leading industrial and household dehumidifier in China.It absorbs moisture by shape memory. Its drying units are made of high polymer materials and fire-safety PBT. The melting point is 300℃, higher than PPS. This core technology of YUNBOSHI has won high reputation in humidity-proof market. The digital humidity and temperature sensor of YUNBOSHI dehumidifier is of SENSIRION, which is famous for its high accuracy from Switzerland. It measures with superb accuracy and no drift with a typical accuracy of ±2 % RH
The LED display screen on the cabinet is large enough to show the humidity and temperature. Its adjustment of the the screen covers the measurement range of ±9%RH. In addition to its convenient maintenance, this drying cabinets can help prevent electronics from mold in wet environment.
2Moisture-proof keyword:Moisture-proof desiccant
After open the LED moisture-proof bag, check that if the desiccant turns red immediately to make sure whether the moisture in the bag is high.
The followings are the measurements taken accroding to the pink shows on the humidity indicator card:
You can use the LED if the the colour of the dots at 10% changes to pink and other dots are blue.
Please bake at low temperature to remove moisture（70℃／24H） if the the colour of the dots at 10% and 20% change to pink and other dots are blue.
If the electronics are applied to reflow or hot bar welding, please send back to our company for the baking at low temperature to remove moisture（70℃／24H） if the the colour of the dots at 10% ,20% and 30% change to pink and other dots are blue.
3Moisture-proof keyword: Reflow Soldering
When LED is taking the method of SMT(surface-mount technology), it means that LED is already expose in the air. It is hard to control the environment under 30℃／60RH and there is water in the solder pastes, so that reflow soldering should be finished in 2 hours after SMT.
Confirm the difference of the actual and theoretic oven temperature before reflow soldering. The highest temperature and time control has to meet the requirements of the products. No matter how LED non leaded reflow soldering temperature curve sets, the maximum 260℃ temperature ranges 5 seconds and 220℃ above ranges 60 seconds, or leads to LED failure. The soldering temperature for big size LED can not be below than the smaller same kinds products.
4Moisture-proof keyword: Moisture-removing Method
The LED products should be kept in sealed and dry environment after use and avoid sealing with transparent taps or staples. High temperature moisture removing has to be done before use again if the products has not been properly stored. The reels and stripes are not resistant to the high temperature so that the products have to been part from the reels. The following methods are for the LED electronics.
Low temperature baking: put the tray into the oven for baking 70℃／24hours before use.
High temperature baking: LED products can be used after 150℃／2hours moisture-removing and the cooling process after baking has to be taken in dry environment for avoid rapid cooling. It is suggested that the material after high temperature moisture-removing not be put in the air immediately. It can be stored in 60℃ oven for gradually cooling and used again in working environment. The trays, carrier tapes and cover tapes are not durable to high temperature. The LED products has to be taken out from the carrier tapes and put in the high temperature oven after the carrier tapes are removed. Mounting should be by hand if high temperature baking moisture-removing is done by users. When the moisture being removed, damp materials should be marked and easy to tell the materials of different voltage, color and luminance.
Are your electronics ready for the rainy season?
Post time: Jun-28-2019