Tin plating

In order to meet the high demands of the automotive, electrical, and electronics industries for connectors and stamped grids – such as low insertion forces, good corrosion resistance, and good solderability – the strip used is required to have surface treatments.

Three main processes are used for coating: hot-dip tinning, electroplating, and electroplating with a subsequent reflow treatment. The hot-dip tinning process is carried out at the Stolberg site itself, while electroplating is performed by external companies.

Accordingly, copper and copper alloy strip can be coated with a variety of metals. Pure tin coatings are particularly important due to their cost efficiency.

Hot-dip tinning

Hot-dip tinning
Strip thickness in mm		Tin layer thickness incl. tolerances (standard tin-plating 99.9 %)	Main properties
0.10 – 1.50	Air level mechanical wipe	0.8 – 1.5 μm	Low insertion force
		1.0 – 3.0 μm	Low insertion force, corrosion protection
		2.0 – 4.0 μm 3.0 – 6.0 μm	Good corrosion protection
		4.0 – 8.0 μm 5.0 – 10.0 μm	Good solderability
		10.0 – 16.0 μm	Special applications

In-house production.

Electroplating

Electroplating
Strip thickness in mm		Main properties
0.20 – 0.80	Tin matte / bright / brushed	Good electrical contact, low insertion force, and / or corrosion protection
	Tin reflowed	Mitigates whiskers
	Nickel	Special applications and diffusion barrier (underlayer)
	TN (available in US)	Very low insertion force
	TQ (available in US)	Long-term solderabiltiy
0.10 – 4.0	Tin matte / bright / brushed	Good electrical contact, low insertion force, and / or corrosion protection
0.10 – 2.0	Tin reflowed	Mitigates tin whiskers
	Advanced reflow tin	Long-term solderability
	Super thin advanced reflow tin (STAR)	Very low insertion force
	Nickel	Special applications and diffusion barrier (underlayer)
	Silver	High corrosion protection, higher temperature resistance

Copper underlayer and selective plating on request.