Silver plating

Silver plating, which would be used for decorative purposes, dishes, dental therapy, etc., due to its [1] distinctive luminous white color and [2] antibacterial action and cleanliness, has recently been used for many parts of electrical and electronic devices due to its excellent [3] electrical conductivity, [4] solderability, and [5] bondability. It also plays an active part in the field of machine parts due to its [6] good thermal-resistant baking seal properties, etc.

Type of plating Features (characteristic value) Characteristic value
Alkaline cyanide silver plating
(1) Dull bath
(2) Semigloss/bright bath
(3) Strike bath
- The electrical conductivity of silver is the highest among practical metals.
(Ag > Cu > Au > Al > Ni > Fe > Pt > Pb)

- Hard silver plating for connectors, terminals, and switches.
Soft silver plating for IC lead frames.

- Bondability and solderability are both good.

- Silver is the most human-friendly metal with antibacterial action.

- The only disadvantage is its tendency for discoloration. In particular, it has high sulfur sensitivity. Silver sulfide is generated, resulting in black discoloration.
Hv70 – 90 (soft), Hv110 – 130 (hard)
Electroless plating bath Replacement type electroless silver plating (primary copper plating)
Silver mirror reaction
(Silver nitrate + ammonia solution + reducing agent)
Utilized as a plating method to manufacture glass mirrors and give conductivity to resins.

Adoption examples

Silver plating

Silver-sulfur binary phase diagram

- Silver, which is often treated as being second to gold, is number one in electrical conductivity and thermal conductivity.

- Non-cyanide silver plating baths having excellent film physical properties have not been developed yet.

- Flash rhodium plating is used to prevent discoloration of silver plating.

- Discoloration of silver products is restored by buffing with precipitated calcium carbonate powder.