The advantages of spring finger contacts

Spring finger contacts offer a set of practical advantages that make them attractive for high-current connector design.

Compact and economical

The spring finger has a simple structure, small size and low material content, which keeps cost down. It meets the space and size requirements of compact equipment designs, and the small number of parts simplifies the design of the connector.

Multi-point contact for high current

The multi-point contact structure provides a high degree of contact concentration and almost lossless contact. This ensures a large current-carrying capacity, good electrical conductivity, and high electrical and thermal stability.

Wear resistance and wide working range

The contact pressure at each point is modest, which gives the spring good wear resistance. Its unique structure also provides a wide working range, allows generous tolerances on the contact surfaces, and adapts well to machining and assembly error, making it well suited to large-scale production.

Development and products

Dongguan SISE (Spring-in-Spring) Electronics Co., Ltd. was founded in October 2011 to design, test and manufacture elastic conductive electronic components, and moved to Chang'an Town, Dongguan in May 2018. The facility includes a CNC lathe workshop, a spring finger workshop, an assembly workshop and a laboratory.

Responding to the connector industry's demand for higher current ratings, SISE developed the two-way coil spring finger (SiS®) and the single-turn spring finger, forming multiple columnar deformation contact points — up to more than 300 — with a service life exceeding 100,000 cycles. Current density and temperature rise are close to those of the connecting cable, and the insertion force is about 10 N.

Applications

The product family covers board-to-board and board-to-wire PCB connectors, cylindrical quick-plug self-locking connectors (plastic and metal shells), male and female connectors with balanced loading, electric-vehicle chargers, and series connectors for high-voltage power battery packs. These are used in advanced high-current energy collection, energy storage and electrical equipment such as electric vehicles, charging stations, wind generators, power supplies, high-speed rail and heavy trucks. The company holds a number of national patents, and its products have passed international standard testing.