D-subminiature - Wire-contact Attachment Types

Wire-contact Attachment Types

There are at least seven different methods used to attach wires to the contacts in D-sub connectors.

• Solder-bucket (or solder-cup) contacts have a cavity into which the stripped wire is inserted and hand-soldered.
• Insulation displacement contacts (IDCs) allow a ribbon cable to be forced onto sharp tines on the back of the contacts; this action pierces the insulation of all the wires simultaneously. This is a very quick means of assembly whether done by hand or automatically.
• Crimp contacts are assembled by inserting a stripped wire end into a cavity in the rear of the contact, then crushing the cavity using a crimp tool, causing the cavity to grip the wire tightly at many points. The crimped contact is then inserted into the connector where it locks into place. Individual crimped pins can be removed later by inserting a special tool into the rear of the connector.
• PCB pins are soldered directly to a printed circuit board and not to a wire. Traditionally through hole plated (THP) board style pins were used but increasingly gull wing surface mount (SMD) connections are used. These connectors are frequently mounted at a right angle to the PCB, allowing a cable to be plugged into the edge of the PCB assembly. Electrical/mechanical anchor points (often soldered) for the connector shell and locking screws are also provided.
• Wire wrap connections are made by wrapping solid wire around a square post with a wire wrap tool. This type of connection was traditionally used in prototyping.

The wire wrap and IDC connections styles had to contend with the issues of incompatible pin spacing to the 0.1 inch ribbon or proto board grid especially for larger pin counts.