Using Solder-Cups for Wire Termination Purposes
In electronic systems, using wires and cables to make connections between devices, PCB’s and discrete instruments is widespread, however, this process can often be challenging as the mating components may not share a common termination style. Attaching those wires and cables to pins, receptacles and connectors designed for this purpose will make these connections more functional and reliable. The two main methods used to make these connections are crimping or soldering the wires to terminals.
Here we are focusing on soldered connections and how a solder-cup feature simplifies and enhances this process. A solder-cup feature has two key attributes; a drilled hole and a portion of the hole exposed, by cutting away material (think of a tube that has the top half removed for a portion of its length). This terminal style is the most efficient and reliable type for soldering wires, it is widely used in connectors such as XLR, D-sub, Mil-Spec and many others.
The solder-cup is designed so the user can easily place the wire in the hole where it will remain stable during the soldering operation. The cut-away portion, or cup shape, allows for a quality solder fillet to form and, depending on the soldering style used, enables a soldering iron easy access to the wire and soldering area. In some soldering processes the iron is placed on the back of the cup while in others the iron is placed right on the exposed wire in the cup. The solder-cup design also allows for easy inspection of the solder joint due to the excellent visibility provided.
For additional help on how to correctly solder these type of terminals watch this video, Basic Soldering For Electronics Lesson 3 - "Cup Terminals", produced by PACE, Inc.
Mill-Max manufactures a wide range of products with solder-cup features including male terminals, receptacles, spring-loaded pins and connectors assembled with these discrete components. There are solder-cup products to choose from which can accept wire sizes from 32 AWG to 14 AWG including: receptacles designed to accept mating pins from .015” to .082” (.38 – 2.08 mm); male terminals with pin diameters of .016: to .078” (.41 – 1.98 mm); spring-loaded pins with .055” to .090” (1.4 – 2.3 mm) stroke. Connectors are offered in vertical mount styles in single and double row while right angle versions are available in single row only. All solder-cup connector products have the cups uniformly aligned to facilitate efficient soldering. Right angle connectors are optimal for applications requiring parallel connections to the board or for minimizing the above-board height of components. Some recently released solder-cup connectors, particularly right-angle versions, incorporate new features and assembly techniques developed by Mill-Max to limit pin rotation in the insulator. This keeps the solder-cups oriented properly during handling and processing.
The following examples showcase some of the products Mill-Max offers to address a variety of wire termination applications.