4 Wafer Mapping & Die Sampling
4-7
11
12
13
14
15
16
17
18 10
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
X coordinate
increasing direction
Y coordinate
increasing direction
Wafer center reference
die (13, 18)
Teaching die (16, 18)
Corner reference die (11, 11)
Coordinate values of dice on the map must be –511 - 511 in both of X/Y directions. The
coordinate increasing directions are determined by the settings of “X/Y Coordinate Increment
To The” of Basic Operational parameters. The above figure shows an example where X
coordinate increases to “Left” and Y coordinate to “Back”.
The wafer central die is a die containing the wafer center determined by the wafer profile
measurement in its die pattern. If the wafer center may come on a street, use a corner die of
the test area as the reference die.
The corner reference die means to give the reference coordinates to die column and row in the
test area edges; so the corner die is a virtual die located on a crossing point of the extended die
column and row. Among those 4 possible corner dice, the one nearest to the origin of the X/Y
coordinate increasing directions is taken as the reference die, which means that all the dice in
the test area have coordinates not less than the coordinates of the reference die.
The reference die teaching is done once for the Device by Data-in on its initial wafer; the
Data-in location is stored in the Device data as the distances from the wafer center. On the
second and succeeding wafers, the die at the location is taken as the reference die and
coordinate values given to the surrounding dice over the map.
When the teaching or target sensing is chosen for a Device in the Device parameters, the
coordinate mapping in reference to the wafer center or edge die under Basic Operational
parameters looses the effect for the Device.