DB22/T 3121-2020 English PDF (DB22T3121-2020)

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DB22/T 3121-2020: Eenvironmental test specifications for COB small pitch LED displays
DB22/T 3121-2020
DB22
LOCAL STANDARD OF JILIN PROVINCE
ICS 31.120
L 47
Environmental Test Specifications for COB Small Pitch LED
Displays
ISSUED ON. MAY 28, 2020
IMPLEMENTED ON. JUNE 16, 2020
Issued by. Jilin Provincial Market Supervision and Administration Office
Table of Contents
Foreword... 3
1 Scope... 4
2 Normative References... 4
3 Terms and Definitions... 4
4 General Requirements... 5
5 Test Method... 5
Environmental Test Specifications for COB Small Pitch LED
Displays
1 Scope
This Standard specifies the general requirements and test methods for the test environment of
COB small pitch LED displays.
This Standard is applicable to the reliability test of COB small pitch LED displays under
different environmental conditions.
2 Normative References
The following documents are essential to the application of this Document. For the dated
documents, only the versions with the dates indicated are applicable to this Document; for the
undated documents, only the latest version (including all the amendments) is applicable to this
Document.
GB/T 2423.55 Environmental testing for electric and electronic products - Part 2.Test
methods - Test Eh. hammer tests
SJ/T 11141-2017 Generic specification for LED displays
SJ/T 11281-2017 Measure methods of light emitting diode (LED) displays
3 Terms and Definitions
For the purposes of this Document, the terms and definitions given in SJ/T 11141-2017 and
SJ/T 11281-2017 and the following apply.
3.1 COB chip on board
An integrated packaging method that directly packages an LED light-emitting chip onto a
module carrier board.
3.2 Display module
An integrated packaging unit that consists of an LED light-emitting chip pixel array with a
resolution of no less than 32×32, a module carrier board, surface packaging materials and a
driving circuit.
5.1.1.2 When the sample is not packaged, the temperature in the test chamber is -10 ℃, and the
storage time is 48 h.
5.1.1.3 When the sample is packaged, the temperature in the test chamber is -30 ℃, and the
storage time is 48 h.
5.1.2 Test method
5.1.2.1 Place the sample in the test chamber; and cool the test chamber at a rate of ≤1 ℃/min
(average value of 5 min time). When the temperature stabilizes at ±2 ℃ of the test temperature,
start recording the time and store for 48 h.
5.1.2.2 At the end of the test, the sample is restored to 25 ℃ at a rate of ≤1 ℃/min (average
value of 5 min) in the test chamber and the temperature is kept constant for 30 min.
5.1.2.3 Take out the sample; check the changes on the outer surface of the sample; and power
on to check whether the working state of the sample control card, the display of each primary
color, the video playback are abnormal or not, and whether the pixel points are out of control.
5.2 Low temperature operation
5.2.1 Test requirements
5.2.1.1 The temperature in the sample test chamber is -10 ℃. After the temperature is reached,
power on and work for 48 h.
5.2.1.2 The sample and the test chamber shall be kept dry, the test chamber shall be kept sealed,
and the initial working temperature shall be room temperature.
5.2.2 Test method
5.2.2.1 Place the sample in the test chamber and power on to reach maximum brightness. The
test chamber is cooled at a rate of ≤1 ℃/min (average value of 5 min time). When the
temperature stabilizes at ±2 ℃ of the test temperature, the time is recorded and the power is
turned on for 48 h.
5.2.2.2 During the test, the sample is observed twice every 24 h; with an interval of ≥4 hours.
Each time the sample is observed, 20 hot start tests within 3 min shall be completed.
5.2.2.3 At the end of the test, the sample is restored to 25 ℃ in the test chamber at a rate of
≤1 ℃/min (average value of 5 min time) and the temperature is kept constant for 30 min, and
the sample is taken out.
5.3 Constant temperature and humidity
5.3.1 Test requirements
5.3.1.1 Temperature 60 ℃ ± 2 ℃, relative humidity 87% ~ 93%, storage for 48 h.
5.3.1.2 The test chamber is kept sealed; the initial working temperature is room temperature;
and the volume of the test chamber is at least 5 times the test sample.
5.3.1.3 During the test, condensed water on the top and side walls of the test chamber shall not
drip onto the sample; and the sample shall be free of condensation.
5.3.2 Test method
5.3.2.1 Place the sample in the test chamber; support the sample and make sure there is no
contact between the sample and the test chamber. The test chamber is heated at a rate of
≤1 ℃/min (average value of 5 min). When the temperature stabilizes at the test temperature,
adjust the humidity to the specified value within 1 h; start recording the time, and store for 48
h.
5.3.2.2 At the end of the test, first reduce the relative humidity and adjust it to less than 60%
within 2 h; then reduce the temperature again. The sample is restored to 25 ℃ in the test
chamber at a rate of ≤1 ℃/min (average value of 5 min) and the temperature is kept constant
for 30 min.
5.3.2.3 Take out the sample and check the changes on the outer surface of the sample. After the
room temperature is restored for 2 h, power on to check whether the working status of the
sample control card, the display of each primary color, the video playback is abnormal or not,
and whether the pixel is out of control.
5.4 Wet heat load
5.4.1 Test conditions
5.4.1.1 Temperature at 40 ℃±2 ℃, relative humidity 87%~93%, power on to operate for 48 h.
5.4.1.2 The test chamber is kept sealed; the initial working temperature is room temperature;
and the volume of the test chamber is at least 5 times that of the test sample.
5.4.1.3 During the test, condensed water on the top and side walls of the test chamber shall not
drip onto the sample; and the sample shall be free of condensation.
5.4.2 Test method
5.4.2.1 Place the sample in the test chamber; support the sample and make sure there is no
contact between the sample and the test chamber. Heat the test chamber at a rate of ≤1 ℃/min
(average value of 5 min). When the temperature stabilizes at ±2 ℃ of the test temperature,
adjust the humidity to the specified value within 1 h; power on to reach the maximum brightness;
and start recording the time when the temperature and humidity are both stable at the severe
level. Power on and run for 48 h. During the test, observe the working status of the sample at
least twice.