5 Key Design Considerations for Plating Connector Parts and Contacts
When plating parts for mission or safety critical applications such military, aerospace, medical and other sensitive uses, there is very little room, if any, for error. Since plating is often the last step when producing various components such as connector parts and contacts, it’s important to consider this phase throughout the product’s lifecycle – starting from design, through production and use. The part must be designed for optimal “platability”. Here are five key considerations that must be made when designing and plating such parts:
Will the parts nest together?
Complete exposure to the plating chemistry is critical to the overall performance and longevity of the finished product. Nesting of parts will prohibit partial or full exposure to cleaning, activating and plating chemistries which will result in poor adhesion or incomplete coverage on the finished part’s surface. If there is a nesting concern, barrel plating should be avoided.
Are there threads or other critical dimensions?
During the electroplating process, the material will follow the electrical current which will have a higher density at the ends of the parts when compared to the middle or ID of the parts. The pitch diameter of a thread will build up four times what a diameter would build up.
Where will the parts be used and how many insertions are expected in cycle testing?
Many electroplated parts are used in harsh environments or are repeatedly inserted and extracted many times during their life cycle. Over time, the resulting friction will slowly wear down the surfaces. Harsh environments could promote corrosion, pitting and other challenges. To minimize these issues, there needs to be sufficient plating thickness to protect the base metal from becoming exposed. The exact thickness depends on the environment and usage, and of course, any applicable standards.
If there is an ID, will there be sufficient solution exchange?
The plater needs to be able to get cleaning, activating and plating solutions into deep holes and properly rinse the holes between steps. The addition, size and position of weep holes is critical to success. The hole needs to be as big as possible without impacting the strength of the part. This sometimes can be achieved with a weep hole the goes all the way through the part essentially doubling its beneficial effect. It should also be located as close to the bottom of the ID as possible.
What is the size of the part and the expected production volumes?
Large brass parts will dent and ding during normal barrel plating. Rack plating must be considered to avoid these issues, but can be expensive.
Small flat parts, parts that nest or micro miniature parts are ideal for Spouted Bed Electrode Plating (SBE) but this specialty process handles only small volumes of parts in each plated lot.
Smaller parts that have deep internal diameters are fragile or susceptible to bending should be vibratory plated. This process is good for all volumes of parts.