Method for forming photo-defined micro electrical contacts
A method of manufacturing a probe test head for testing of semiconductor integrated circuits includes: defining shapes of a plurality of probes as one or more masks; a step for fabricating the plurality of probes using the mask; and disposing the plurality of probes through corresponding holes in a first die and a second die. The step for fabricating the plurality of probes may include one of photo-etching and photo-defined electroforming.
1. A method of fabricating a plurality of micro probes comprising the steps of:
providing one or more masks, each of said one or more masks including a plurality of probe shapes, each of said plurality of probe shapes including a probe base, a probe shaft connected to said probe base, a probe end connected to said probe shaft, and one or more raised surfaces on at least one of said probe base, said probe end and said probe shaft;
applying a photoresist to a side of a first metal material;
overlaying said mask on said side of said first metal material;
exposing said photoresist to light passed through said mask;
developing said photoresist;
removing a portion of said photoresist to expose a portion of said first metal material,
electroforming a second metal material on said exposed portions of said first metal material; and
removing said second metal material to produce a plurality of probes, each of said plurality of probes including a probe base, a probe shaft connected to said probe base, a probe end connected to said probe shaft, and one or more raised surfaces on at least one of said probe base, said probe end, and said probe shaft.
2. The method of claim 1 wherein said first material is stainless steel.
3. The method of claim 1 wherein said second material is selected from one of Nickel and Nickel-Cobalt alloy.
4. A micro probe comprising:
a probe base having a generally uniform thickness bounded by a plurality of edges and extending for a substantially straight length in a plane;
a probe shaft connected to said probe base said probe shaft of said generally uniform thickness, bounded by a plurality of edges, and extending along a curved expanse within said plane;
a probe end connected to said probe shaft said probe end of said generally uniform thickness, bounded by a plurality of edges, and extending for a substantially straight distance within said plane said straight distance being approximately parallel to said straight length; and
one or more raised surfaces positioned on at least one of said probe base, said probe shaft and said probe end, wherein said one or more raised surfaces are formed from a mechanical process.
5. The micro probe of claim 4 wherein said uniform thickness is between 2 mils and 5 mils.
6. The micro probe of claim 5 wherein said uniform thickness is between 3 mils and 4 mils.
7. The micro probe of claim 4 wherein said mechanical process is an electroforming process.