度金，我是不知道，度SN我是知道！

下一个USB的规范,里面有接头镀层厚度的要求

沒有吧

6.5.4.3 Plug (Male) Contact Materials
Substrate Material: 0.30 + 0.05 mm half-hard phosphor bronze.
Plating: Contacts are to be selectively plated.
A. Option I
1. Underplate: Minimum 1.25 micrometers (50 microinches) nickel. Copper over base material
is optional.
2. Mating Area: Minimum 0.05 micrometers (2 microinches) gold over a minimum of
0.70 micrometers (28 microinches) palladium.
3. Solder Tails: Minimum 3.8 micrometers (150 microinches) bright tin-lead over the
underplate.
B. Option II
1. Underplate: Minimum 1.25 micrometers (50 microinches) nickel. Copper over base material
is optional.
2. Mating Area: Minimum 0.05 micrometers (2 microinches) gold over a minimum of
0.75 micrometers (30 microinches) palladium-nickel.
3. Wire Crimp/Solder Tails: Minimum 3.8 micrometers (150 microinches) bright tin-lead over
the underplate.
C. Option III
1. Underplate: Minimum 1.25 micrometers (50 microinches) nickel. Copper over base material
is optional.
2. Mating Area: Minimum 0.75 micrometers (30 microinches) gold.
3. Solder Tails: Minimum 3.8 micrometers (150 microinches) bright tin-lead over the
underplate.

是指这一条吗，那应该是0.75um

USB1.1----插头端子镀金15U"

USB2.0----插头端子镀金30U"