LED SMD 3535/5050 outdoor application analysis
SMD 3535/5050 outdoor application analysis
More and more SMD led screens were applied in outdoor led display market because the SMD led screen has better lighting mixing,color mixture than DIP(Dual In-line Package) screen.Whether outdoor SMD 3535/5050 is safe enough for outdoor application?Let us see followed analysis.
Firstly,please let us check the SMD structure.
1,Thermal Expansivity,
1.1,PPA Thermal Expansivity is 1.6*10-4M/℃
1.2,Epoxy Thermal Expansivity is 0.671*10-4/℃
1.3,Metal Thermal Expansivity is 0.167*10-4/℃
The dimension and volume of different material would change differently and inner stress came from different direction after temperature changed.So,that’s better to choose same or similar Thermal Expansivity material for the outdoor SMD lamp.Meanwhile,the inner stress should linear change in certain range.So,the designer and end user can know how to use the outdoor SMD in certain condition.
2,Environmental influence
2.1.Temperature
2.1.1.Electro-Themic
The electro-themic is inner to outer process instead of heat completely at same tiem.That’s safe if the stress changed under certain range.So,the key point is how to control the stress change.
2.1.2.Ambient temperature
SMD lamp temperature change from surface to inner when no power on.Same situation as Electro-themic.
2.2.Humidity
That’s similar as let SMD lamp work in atomized water and liquid if the environmental is rainy or moist.The thermal expansivity is different when the intermediary is water.The process is surface to inner and part to overall.The stress would different at time,direction.So,the tightness is the most important point
2.3.PH value
The thermal expansivity would be different when the intermediary is atomization acid-base substances.
2.4.Ultraviolet rays(UV)
The UV is inevitable if outdoor application. UV would be more when summer. Accelerated ageing of materials.The ageing ratio is different for the PPA and Epoxy.So,all products apply outdoor should be UV-proof.
2.5.Dust
Dust can permeate into SMD lamp after long term wind and rain.The thermal expansivity would be changed if the dust is too much.
2.1.Temperature
2.1.1.Electro-Themic
The electro-themic is inner to outer process instead of heat completely at same tiem.That’s safe if the stress changed under certain range.So,the key point is how to control the stress change.
2.1.2.Ambient temperature
SMD lamp temperature change from surface to inner when no power on.Same situation as Electro-themic.
2.2.Humidity
That’s similar as let SMD lamp work in atomized water and liquid if the environmental is rainy or moist.The thermal expansivity is different when the intermediary is water.The process is surface to inner and part to overall.The stress would different at time,direction.So,the tightness is the most important point
2.3.PH value
The thermal expansivity would be different when the intermediary is atomization acid-base substances.
2.4.Ultraviolet rays(UV)
The UV is inevitable if outdoor application. UV would be more when summer. Accelerated ageing of materials.The ageing ratio is different for the PPA and Epoxy.So,all products apply outdoor should be UV-proof.
2.5.Dust
Dust can permeate into SMD lamp after long term wind and rain.The thermal expansivity would be changed if the dust is too much.
So,the SMD lamp manufacturer must choose same or silimar thermal expansivity,UV-Proof material for the lamp and improve the lamp sealing process if they want to apply 3535/5050 lamp for outdoor led display products.
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