3 Automatic Needle Alignment
3-7
to the description stated on the next page.
[Notice]
Some of probe cards has multilayered construction as
shown like figure left. As for these type of cards,
please note that data to setup is not only the part where
probe tip is exposed, but include the height of middle
construction part as well.
For example: as for the probe card as shown at left,
enter the full length data measured from the bottom
surface that contacts to card holder to the probe needle
tip as “needle height of the card”. As for this construct
type ,“d2” will be equivalent to the “full length”. Data
for “d1” shall be “0(zero)”
Remark
Needle height (needle length) setting for probe cards is an important process. The Prober
assumes that the needle tip is positioned around the set height at the first needle alignment, and
starts probing. When the needle is found and the needle alignment is completed, the parameter
value is updated with the detected height. The second needle alignment is carried out with the
updated value.
If the needle height value is small (the set needle value, or the needle value of the read device, or
the default needle value is small), and the actual needle of the probe card is long, the damage
described below may occur in the worst case. To avoid such damage, make an alignment with the
actual needle height of the probe card. When the needle height is unknown, set a large value to
avoid damage.
1) When the actual needle value is completely different, the needle alignment camera itself may
contact the probe needle, probe card, or card folder during needle alignment operation.
2) When the thickness and needle length of the probe card are completely different from the cards
with the initial specification that are normally used, the chuck or the cleaning unit may also
interfere with the card folder.
3) The probe card height is set wrong, and it will cause a needle alignment error. The proper
operation to follow is to focus the needle tip using a camera image and make an alignment. If
the camera was moved up with the wrong needle height, the camera may contact the needle.
Exercise care during operation.
If the operator failed to recognize a correct needle tip after the needle alignment error and carried
out Data-In operation, the Prober identifies the set needle height as the default value. Thus, (when
the actual needle length is longer than the set value,) the wafer contact occurs at a wrong height,
possibly damaging the wafer and/or probe card.
Proper setting
Probe card needle height is shorter than the actual needle height.
d2
probe support
Probe tip
board
card holder
Stiffner plate for top surface
d3
