Due to the differing processes, what is acceptable tolerance in穿孔式 connectors is often not permissible in board-to-board connectors. To ensure high-quality solder joints, the wire design of the connectors must have adequate welding surfaces while also exerting the tensile strength of the material to resist external pulling forces. This is particularly critical in micro-space connectors.
The commonly used contact materials are phosphor bronze and beryllium copper, as the metal contacts of connector outlets must be forged into shape on high-precision forging beds, maintaining a reasonable ratio of insertion force to pull-off force. Due to the unique toughness of the outlet contacts after welding, the reliability of signal transmission is ensured even after multiple insertions and withdrawals of the outlet from the terminal.
When selecting contact materials, the focus should be on the fatigue resistance and toughness of the metal. In fact, phosphor bronze is superior to beryllium copper. The electroplating of contacts still employs tin plating over nickel, gold plating, or a multi-layer electroplating process. It should be noted that contacts should generally be electroplated in a multi-layer manner, meaning gold plating on the contact portion with the terminal to ensure a high-quality connection and signal transmission, and tin plating on the lead portion for easy soldering.
The increasing use of micro pitch connectors requires manufacturers to employ high-reliability phosphor bronze materials. Heat-treated phosphor bronze particularly showcases its excellent fatigue resistance and toughness. Therefore, phosphor bronze is commonly used for small pitch connectors. For connectors with larger pitch, beryllium copper contacts are sufficient.
