背板表面或内部不允许存在明显的污垢、斑点、杂质（大于1mm*1mm 面

背板表面或内部不允许存在明显的污垢、斑点、杂质（大于1mm*1mm 面积的杂物不允许小于1mm*1mm 面积的杂物允许每个平方米2 个）等现象

ผลลัพธ์ (อังกฤษ) 1:

Back plate surface or obvious stains, spots, impurities is not allowed (more than 1mm*1mm area of debris is not less than 1mm*1mm debris allowed per square meter of area 2)

ผลลัพธ์ (อังกฤษ) 2:

Backplane surface or inside allowed obvious dirt, spots, impurities (greater than 1mm * 1mm area of ​​debris less than 1mm * 1mm area does not allow the debris to allow each square meter 2) and other phenomena

ผลลัพธ์ (อังกฤษ) 3:

The back surface or interior does not allow the existence of obvious dirt, spots, impurities (greater than the size of the 1mm*1mm area of the debris is not allowed to be less than the size of the 1mm*1mm 2 per square meter), and so on.