Helical microelectronic contact and method for fabricating same
View Patent ↗A microelectronic spring contact for making electrical contact between a device and a mating substrate and method of making the same are disclosed. The spring contact has a compliant pad adhered to a substrate of the device and spaced apart from a terminal of the device. The compliant pad has a base adhered to the substrate, and side surfaces extending away from the substrate and tapering to a smaller end area distal from the substrate. A trace extends from the terminal of the device in a coil pattern over the compliant pad to its end area, forming a helix. At least a portion of the compliant pad end area is covered by the trace, and a portion of the trace that is over the compliant pad is supported by the compliant pad. In an alternative embodiment, the pad is removed to leave a freestanding helical contact.
1. A microelectronic contact structure for making electrical contact to a terminal of a semiconductor device, the contact comprising:
a compliant pad having a base adhered to the semiconductor device and side surfaces extending away from the semiconductor device and tapering to an end area distal from the semiconductor device; and
a trace extending from the terminal of the semiconductor device and over a portion of the side surfaces of the compliant pad to the end area, thereby defining a helix.
2. The microelectronic contact of claim 1 , wherein the compliant pad is spaced apart from the terminal.
3. The microelectronic contact of claim 1 , wherein the compliant pad is essentially non-conductive.
4. The microelectronic contact of claim 1 , wherein the compliant pad is a shape selected from a pyramid, a truncated pyramid, a prism, a cone, a truncated cone, and a hemisphere.
5. A microelectronic contact structure comprising:
a freestanding resilient portion coiled in a shape of a tapered helix extending from a semiconductor device, the resilient portion formed by patterning a conductive material over a tapered sacrificial pad, and removing the pad;
a conductive trace portion attachably extending from a conductive terminal of the semiconductor device and to an end of the resilient portion proximal to the semiconductor device; and
a contact tip portion at an end of the resilient portion distal from the semiconductor device.
6. The microelectronic contact of claim 5 , wherein the resilient portion is tapered in a shape selected from a pyramid, a truncated pyramid, a prism, a truncated prism, a cone, a truncated cone, and a hemisphere.
7. The microelectronic contact of claim 5 , wherein the contact structure is coated with gold or alloy thereof.
8. The microelectronic contact of claim 5 , wherein the resilient portion tampered from the distal end.
9. A microelectronic contact structure for making electrical contact to a terminal of a probe card, the contact comprising:
a compliant pad having a base adhered to the probe card and side surfaces extending away from the probe card and tapering to an end area distal from the probe card; and
a trace extending from the terminal of the probe card and over a portion of the side surfaces of the compliant pad to the end area, thereby defining a helix.
10. The microelectronic contact of claim 9 , wherein the compliant pad is spaced apart from the terminal.
11. The microelectronic contact of claim 9 , wherein the compliant pad is essentially non-conductive.
12. The microelectronic contact of claim 9 , wherein the compliant pad is a shape selected from a pyramid, a truncated pyramid, a prism, a cone, a truncated cone, and a hemisphere.
13. A microelectronic contact structure comprising:
a freestanding resilient portion coiled in a shape of a tapered helix entending from a probe card, the resilient portion formed by patterning a conductive material over a tapered sacrificial pad, and removing the pad;
a conductive trace portion attachably extending from a conductive terminal of the probe card to an end of the resilient portion proximal to the probe card;
a contact tip portion at an end of the resilient portion distal from the probe card.
14. The microelectronic contact of claim 13 , wherein the resilient portion is tapered in a shape selected from a pyramid, a truncated pyramid, a prism, a truncated prism, a cone, a truncated cone, and a hemisphere.
15. The microelectronic contact of claim 13 , wherein the contact structure is coated with gold or alloy thereof.
16. The microelectronic contact of claim 13 , wherein the trace is tapered from the distal end.