本文將傳統的彈贊-銷針或彈簧-平墊式連接器針對幾項設計規格,也則,(一)接觸壓力,(二)接觸電阻,(三)接觸摩擦及(四)接觸雜訊等,加以更仔細的評估。近年來連接器隨著電子構裝密度之增加和電子訊號傳遞之加速,己經面臨其極限點或徘徊在十字路口而迷惘不知應該將傳統的連接器再加以微細化,或乾脆轉移方向專注於更有潛力的多點微接觸方面的開發。
一般從事研究者多認為應付高頻問題時最簡單的迴避方法乃是增加地線/訊號的比例便能減少交吵(crosstalk)或其他各種電噪音。但經過小心觀察結果認爲:今日的彈簧-銷針連接器己經受限於天生條件很難再超越其功能極限,對將來的高密度與高頻率的應用將失去其競爭能力。
所謂平墊對平墊的多點微接觸方法在機械性方面的優點可以說是顯而易見的。其中最重要的是摩擦方向的改變,從傳統的垂直於接觸力方向變成平行於接觸力方向,因而顯著減少插拔過程所引起的摩擦力和摩擦磨耗。
本文所提出的多點微接觸觀念雖然不是創新,早由電接觸先驅者賀門(R. Holm)於三十多年前就曾預測。美國IBM公司也曾花了二十多年開發了DendriPlate爲商標的平墊對平墊的連接器,唯因價格昂貴而難推廣。本文秉持同一精神試以新而簡單的方法製出比DendriPlate更廉價且更堅固實用的多點微接觸試品,初步實驗數據頗令曆目信將來的高密度與高速度連接器將朝向此目標發展,使連接器工業在新的世紀將有更大發揮空間。
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.