Method of determining the tip angle of a probe card needle
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorShu Min Chen
Life of this patent
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Abstract
A method is provided for determining the tip angle of a probe needle used to measure electrical characteristics of a circuit device, such as an IC. The spatial coordinates (X1, Y1, Z1), (X2, Y1, Z2), (X3, Y1, Z3), of three spaced apart locations A, B, C along the outer free end of the needle tip are measured. The slopes m1, m2 of two longitudinal sections of the needle determined, and the tip angle is then calculated using the slopes m1, m2.
Claims6
A method of determining the angle of a probe needle tip used in a probe assembly for contacting and measuring electrical characteristics of a circuit device, wherein said needle tip includes first and second non-coaxial sections along the outer free end thereof, said method comprising the steps of:
- (A) determining the spatial coordinates (X1, Y1, Z1), (X2, Y1, Z2), (X3, Y1, Z3), respectively of three points A, B, C along the outer free end of said needle tip;
- (B) determining the slopes m1, m2 of said first and second sections using the spatial coordinates (X1, Y1, Z1), (X2, Y1, Z2), (X3, Y1, Z3), determined in step (A), according to the formulas:
- m 1 = Z 2 - Z 1 X 2 - X 1
- and m 2 = Z 3 - Z 1 X 3 - X 1 , and ;
- (C) determining said angle using the formula:
- tip angle = tan - 1 m 2 - m 1 1 + m 1 m 2 .
Dependencies are inferred from the claim text.