Wafer probing test apparatus and method of docking the test head and probe card thereof

1. Wafer probing test apparatus, comprising:

a main body;

a test head disposed over said main body, said test head having a lower surface and a plurality of pogo pins extending downwardly at said lower surface;

a probe card to which the test head is to be docked, the probe card being supported on said main body;

a position sensor operative to sense whether the test head is oriented properly relative to the probe card; and

a docking height sensor operative to sense when the test head is disposed at a predetermined height relative to the probe card once the test head is properly oriented with respect to the probe card.

2. The wafer probing test apparatus according to claim 1 , wherein said docking height sensor includes a down limit switch that is turned on when said pogo pins are contacted with the probe card and whether the test head is oriented properly with respect to the probe card or not.

3. The wafer probing test apparatus according to claim 2 , wherein said docking height sensor operates the down limit switch and comprises at least one height sensor protrusion that is contacted with the probe card simultaneously when the pogo pins are contacted with the probe card.

4. The wafer probing test according to claim 3 , wherein said probe card has a plurality of holes therein, and said position sensor comprises a plurality of position sensor protrusions exposed at the bottom of said test head and which protrusions are insertable and penetrated into the holes, respectively.

5. The wafer probing test according to claim 4 , wherein said position sensor further includes at least one position limit switch judging a docking position by lifting said test head and adjusting the orientation of said test head, when said position sensor protrusions are contacted with a point except the holes and turned off.

6. The wafer probing test apparatus according to claim 5 , wherein said position sensor includes at least two said position limit switches.

7. The wafer probing test apparatus according to claim 5 , wherein each of said position sensor protrusions is longer than said height sensor protrusion.

8. The wafer probing test apparatus according to claim 1 , wherein said probe card has a plurality of holes therein, and said position sensor comprises a plurality of position sensor protrusions exposed at the bottom of said test head and which protrusions are insertable and penetrated into the holes, respectively.

9. The wafer probing test apparatus according to claim 8 , wherein said position sensor further includes at least one position limit switch judging a docking position by lifting said test head and adjusting the orientation of said test head, when said position sensor protrusions are contacted with a point except the holes and turned off.

10. The wafer probing test apparatus according to claim 9 , wherein said position sensor includes at least two said position limit switches.

11. The wafer probing test apparatus according to claim 1 , wherein said main body comprises an insert ring which has a plurality of guide holes in an upper surface thereof, and said probe card has a plurality of guide pins inserted in the guide holes.

12. A method of docking a test head of a wafer probing test machine with a probe card, said method comprising:

turning on a position sensor that is operative to sense the orientation of the test head relative to the probe card;

turning off a docking height sensor that senses when the test head is disposed at a predetermined distance relative to the probe card;

subsequently forcing the test head down towards the probe card until the test head reaches a predetermined height;

once said test head arrives at said predetermined height, using said position sensor to determine whether the test head is properly oriented with respect to said probe card;

if the position sensor remains in its on-state and the docking height sensor senses that the test head is disposed at said predetermined distance relative to the probe card, turning on said docking height sensor;

if the position sensor becomes turned-off, lifting said test head, adjusting the orientation of said test head, and then moving the test head back down to the predetermined height;

stopping the test head once the docking height sensor has been turned on; and

locking the test head in place once the test head is stopped and said docking height sensor has been turned on.

13. The method according to claim 12 , wherein the turning off of the position sensor includes turning off at least one position limit switch when a sensing protrusion formed on the bottom of the test head is contacted with a point on the probe card.

14. The method according to claim 12 , wherein the turning on of the docking height sensor includes turning on at least one down limit switch when a height sensing protrusion formed on the test head is contacted with the probe card.