A New Approach for Multi-Microcontactsfor High Density and High Speed Connectors and Interconnects

Abstract

Traditional spring-pin or spring-card connectors are put in test under a closer examination in terms of some connecter design criteria, namely, 1. Contact force, 2. Contact resistance, 3 Contact wiping, and 4. Contact noise. The connectors trend of going higher in packaging density and faster in signal transmission speed has reached a crucial point or has come to a cross road--perplexingly wondering whether we should further miniaturize the traditional connectors or shift our effort toward more promissing multi-microcontacts. Mechanical advantages for such pad-on-pad multi-microcontacts over traditional spring-pin connectors are quite obvious. Among them the most significant one is the change of wiping direction from being normal to the contact force to being parallel to the contact force, thus significantly reducing both insertion friction and wiping wear. Electrical consideration of increasing ground pins so as to reduce crosstalk noise and some other electrical noises appears to be the easiest solution for high speed problem. But a careful examination concludes that: Today's spring-pin connector is inherently and practically incapable of exceeding much its performance limits for many of tomorrow’s high density and high speed applications. A new approach for multi-microcontacts is proposed and compared with the existing product called DendriPlate(superscript ®). Comparisons were also made with a traditional spring-pin modular connector with similar signal/ground ratios. Advantages of shifting toward this new type of pad-on-pad connectors of multi-microcontacts are quite convincing. However, more experimental data and process improvements are required before a new connector product of tomorrow can be materialized.