Probe Head Including a Guide Plate with Angled Holes to Determine Probe Flexure Direction
Vertical probe arrays having angled guide plates are provided. With this configuration, the probes can be straight conductors (when mechanically undeformed) and the mechanical bias provided by the angled guide plates can ensure the probes have a well-defined deformation when the probe array make contact to the device under test. This allows the use of straight conductors as probes without suffering from probe shorting and mechanical interference caused by straight probes buckling in unpredictable directions when vertically compressed.
1 . A vertical probe array comprising:
an upper guide plate;
a lower guide plate;
an array of vertical probes, wherein each of the vertical probes passes though corresponding holes in the upper and lower guide plates, wherein each of the vertical probes is mechanically elastic and electrically conductive;
wherein each of the probes is a straight conductor when not subjected to a mechanical force;
wherein the holes of at least one of the upper and lower guide plates are angled at a bias angle configured to provide a mechanical bias to the probes sufficient to define a buckling direction of each probe when the array of vertical probes is vertically compressed.
2 . The vertical probe array of claim 1 , wherein the holes of the upper guide plate are angled.
3 . The vertical probe array of claim 1 , wherein the holes of the lower guide plate are angled.
4 . The vertical probe array of claim 1 , wherein the holes of the upper guide plate are angled and wherein the holes of the lower guide plate are angled.
5 . The vertical probe array of claim 1 , wherein the bias angle is 1 degree or larger.
6 . The vertical probe array of claim 1 , wherein the bias angle is above a critical angle that is determined by a ratio of guide plate offset to guide plate spacing.