Surfaces
The PCB surface serves to prepare the connecting faces for the intended packaging method and to make them storable. Today, the packaging method often goes far beyond soldering. The following technologies are used:
- soldering, often several times and lead-free
- TS-bonding (thermosonic, with aluminium wire, thick wire or tapes)
- US bonding (ultrasonic bonding, with gold wire)
- conductible adhesives
- press-fitting
- ZIF socket (zero insertion force socket)
- direct connector/edge connector/multipoint connector
- push contacts, sliding contacts
- crimping
The following surfaces are available:
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immersion tin | |||||||||||
| HAL SnPb | ||||||||||||
| HAL SnCuNi | ||||||||||||
| solder depot | ||||||||||||
| galv. Ni/SnPb | ||||||||||||
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ENIG | |||||||||||
| EN/imm. thick gold | ||||||||||||
| galv. Ni/fine gold | ||||||||||||
| galv. Ni/hard gold | ||||||||||||
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imm. silver | |||||||||||
| galv. Silber | ||||||||||||
| bare Cu | ||||||||||||
| OSP | ||||||||||||
| carbon print |
In spite of the wide range of surfaces available today, most PCBs are made with the universal surfaces chemical zinc and chemical Ni/Au.