Updated: September 12th, 2016

A good connector design requires attention to the separable interface front end, the permanent interface back end, and the contact retention area. Bill Garver of APEX Electrical Interconnection Consultants provides a checklist of these design considerations.



circle-check-300x300There are fundamentally three specific elements of an electrical contact that are used within a multiple-position connector. A multiple-position connector, for this discussion, is defined as one which contains a molded plastic housing and a series of contacts that are attached to wires or printed circuit boards and installed into the molded housing. The contacts may be installed either before (insulation displacement) or after (crimp-snap) the wires have been attached. The contact elements are:

  • Separable interface front end
  • Permanent interface back end
  • Contact retention area

Here we detail several of the important design considerations for each of the three elements.

The following are a few of the critical design attributes, which should be considered for the separable interface front end:

  • Contact base material
  • Contact plating
  • Allowable mating force
  • Contact lubricant
  • Surface finish (roughness)
  • Geometry of contact surfaces
  • Closed entry of contacts
  • Lead-in condition
  • Insertion depth
  • Anti-overstress design
  • Contact compliance
  • Mechanical support of contact beams
  • Contact mating sequence
  • Contact bifurcation

Let’s look at each of the above design attributes and the selection criteria.

Contact Base Metals

    • Steel – used in high-temp