Wafer prober

A wafer prober, comprising:

• a wafer holder for holding a wafer;
• a stage operable to move said wafer holder substantially along an X axis and a Y axis;
• a card holder for holding a probe card having a probe needle which is contactable to a bonding pad of the wafer as it is held by said wafer holder;
• and
• detecting means operable to detect the position, with respect to the directions along the X and Y axes, of the probe needle of the probe card as it is held by said card holder, said detecting means including a needle sensing unit which is movable as a unit with said wafer holder, said needle sensing unit having a source of a laser beam, a photodetector and a detecting optical system which is operable to direct the laser beam from said source in a direction substantially parallel to a plane defined by the X and Y axes and to direct the laser beam to said photodetector.

A wafer prober, comprising:

• a wafer holder for holding a wafer;
• a stage operable to move said wafer holder substantially in each of the directions of X and Y axes and in the direction of a Z axis which is perpendicular to the X and Y axes;
• a card holder for holding a probe card having a probe needle which is contactable to a bonding pad of the wafer as it is held by said wafer holder;
• and
• detecting means operable to detect the position, with respect to each of the X-axis direction and the Y-axis direction, of the probe needle of the probe card as it is held by said card holder, said detecting means including a needle sensing member which is resiliently supported by a spring member movable in the Z-axis direction as a unit with said wafer holder and which is contactable to the probe needle of the probe card as it is held by said card holder, wherein the position of the probe needle is detected on the basis of inclination of said needle sensing member by contact to the probe needle.

A wafer prober, comprising:

• a wafer holder for holding a wafer;
• a stage operable to move said wafer holder substantially in the direction of X and Y axes and in the direction of a Z axis which is perpendicular to the X and Y axes;
• a card holder for holding a probe card having a probe needle which is contactable to a bonding pad of the wafer as it is held by said wafer holder;
• and
• detecting means operable to detect the position of the probe needle of the probe card as it is held by said card holder, said detecting means including a needle sensing unit movable as a unit with said wafer holder at least in each of the X-axis direction and the Y-axis direction, said needle sensing unit having a source of a laser beam, a photodetector and a detecting optical system effective to direct the laser beam from said source substantially in parallel to a plane defined by the X and Y axes and to direct the laser beam to said photodetector, said detecting means further including a deformable plate movable with said wafer holder in the Z-axis direction, wherein the position of the probe needle in the Z-axis direction is detected on the basis of deformation of said plate by contact of the probe needle to said plate.