Immersion Tin surface treatment

6 layer immersion Tin pcb board. the base Material is FR4 KB6167 (TG170). Copper thickness both inner and outer 1oz finished. Board Thickness is 1.6mm and the Min.Hole Size is 0.2mm. Min.Line Width/Min.Line Spacing is 0.13mm/0.13mm. green solder-resist & with white silkscreen. E-test: 100%.
Immersion Tin is a common surface treatment, relatively cheap.The advantage is that the surface is smooth and easy to do pcb assembly.