Miniaturized Spring Contact

Abstract

A method of manufacturing an array of miniaturized spring contacts is disclosed. The invention teaches a symmetric design of the spring contact with two anchoring traces at each side of the spring contact, and teaches a method of forming the spring contact with a continuo us, zero-stress core member throughout the entire body of the spring contact; besides these, the invention enables easy manufacturing of integrated fine pitch spring contact arrays, allows fabrication of such spring contact arrays with extremely uniform spring height and good electrical and mechanical properties.

Description

FIELD OF THE INVENTION[0001]The present invention relates to miniaturized spring contacts manufactured using micro-electronic-mechanical-systems (MEMS) fabrication techniques, and particularly to miniaturized spring contacts in application of bonding and testing of semiconductor integrated circuitry (IC) devices.BACKGROUND OF THE INVENTION[0002]Semiconductor devices, such as integrated circuitry (IC), are massively manufactured by fabricating hundreds or even thousands of identical circuitry on a single semiconductor wafer, and hundreds or thousands of such wafers daily using photolithography in combination with various other material additive and removal processes. After being fabricated, these semiconductor devices are subsequently electrically connected to external electrical testers through electrical contact devices, such as probe cards, so that they can be tested.[0003]An electrical contact device, such as probe card, is an integral part of connecting device to connect IC devi...

AI Technical Summary

Benefits of technology

[0010]In general, it is the object of the present invention to provide a miniaturized spring contact and an array of such miniaturized spring contacts that employ great compliance, great spring integrity, good electrical conductivity, fine dimensions, easy fabrication, and great reliability.

[0015]In above embodiment of the present invention, the aspect of the routing metal layer allows the flexibility of have large number of fine spring contacts in a small area by routing the electrical connection of the spring contacts to a much larger area to connect to the available through substrate electrical connections.

[0016]In a deviation of above embodiment of the present invention, prior to releasing the spring structures, a first plurality of metal layers may be plated by electroplating or electroless plating, then the spring structures are released by dissolving the entire leftover Si material of the wafer A, and a second plurality of metal layers is then plated, either by electroplating or electroless plating. The plating of the first plurality of metal layers increases the mechanical strength of the spring structures so that they withstand the releasing process.

[0018]In another embodiment of the present invention, a particular application of a probe card using the spring contacts is disclosed. The probe card includes a plurality of spring contacts of the present invention. The spring contacts of the probe card may be temporarily electrically connected to at least one testing pad of the external electrical device which is coupled to circuitry thereof The spring contacts may also contact all of the testing pads of the external electrical device to test all of the circuitry of the external electrical device at substantially the same time, thus eliminating the need to test the circuitry in sections.

Problems solved by technology

This poses difficulties for traditional epoxy ring contact and blade contact technologies, and also poses desires for improvement and new designs of the micro-spring contact technology.

However, this type of spring contacts intrinsically suffers from some process deficiencies.

Second, the released springs, prior to the electroplating, are fragile and easy to fracture during the following process.

Third, the large tension force applied on the spring contacts during testing creates large stress on the spring bases anchored on the substrate, therefore causes tendency of de laminations and other failures, and raises concerns of reliability.

The problem of this type of spring contacts is that the spring contacts are too long.

This type of spring contacts also raises concern of mechanical failure as the building blocks are only adhered together through adhesion.

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