chuck_poi_stepping.py

from sentio_prober_control.Sentio.ProberSentio import SentioProber
from sentio_prober_control.Sentio.Enumerations import ChuckSite, Stage, PoiReferenceXy, Module, TestSelection, RoutingStartPoint, RoutingPriority

#
# This example will demonstrate how to navigate the chuck with a point of interest list (POI)
#
# This script will set up a list with POI spread across the die. It will then use the chuck to step
# over all POI in the list for all active dies
#

# Required Preconditions to run this script
#    - You need a system with a motorized chuck
#    - a chuck home position must be set
#
def check_preconditions(prober : SentioProber) -> None:
    # 1.) Check whether the machine has a motorized chuck.
    if not prober.has_chuck_xyz():
        raise Exception("This script requires a motorized chuck in order to run!")

    # 2.) Check whether the home position of the chuck wafer site is set
    hasHome, hasContact, overtravelActive, vacuumOn = prober.get_chuck_site_status(ChuckSite.Wafer)
    if not hasHome:
        raise Exception("Home position must be set to execute this script!")

    # 3.) Check whether the die reference position is set.
    # This script requires a valid die reference position. The die reference position is the distance from the corner
    # of the die to the pad. Only when it is set can SENTIO know where the pad is located inside the die.
    if not prober.map.die_reference_is_set():
        raise Exception("The die reference position is not trained! Therefore SENTIO does know where the home position is located inside the die!")

#
# Distribute 9 POI across the die. The POI layout will look like shown here:
#
#      1-------------2-------------3
#      |                           |
#      |                           |
#      |                           |
#      |                           |
#      |                           |
#      4             5             6
#      |                           |
#      |                           |
#      |                           |
#      |                           |
#      |                           |
#      7-------------8-------------9
#
# - Numbers indicate the POI index and their position.
# - POI number 5 is at the center of the die
def set_poi(prober : SentioProber) -> None:
    # 1.) get the die Size
    sx, sy = prober.map.get_index_size()
    print(f"Die size is {sx}, {sy} µm")

    # IMPORTANT:
    # The POI MUST be inside of the Die! If you set up POI at the edge of the wafer you may experience undefined
    # behavior! 
    #   - If you place a poi on a die edge it cannot be assigned to a specific die because its
    #     position is ambiguous.
    #   - The chuck can be positioned with +/- 1..2 microns accuracy. This area should be avoided when setting poi!
    #   - Sentio is using the chuck position to determine the current die. If the chuck is closer than 1 µm to a die edge
    #     SENTIO may incorrectly determine that it is in the neighboring die due to limited chuck accuracy!
    #   - In this example I avoid the trouble by assuming the die is slightly smaller than it really is.
    edge_margin = 4
    sx -= edge_margin  # 2 µm on the sides of the die are the poi "no go" zone
    sy -= edge_margin  # 2 µm on the sides of the die are the poi "no go" zone

    die_center_x = sx / 2
    die_center_y = sy / 2

    # Create this many rows and columns of POI.
    ncols = 3
    nrows = 3

    dx = sx / (ncols-1)
    dy = sy / (nrows-1)

    print(f"Creating {ncols * nrows} points of interest:")

    # Set up a poi map for the chuck which i using the die center as a reference position
    prober.map.poi.reset(Stage.Chuck, PoiReferenceXy.DieCenter)

    ct = 0
    for r in range(-nrows//2, nrows//2):
        for c in range(-ncols//2, ncols//2):
            ct = ct + 1
            poi_x = die_center_x + c * dx
            poi_y = die_center_y + r * dy
            print(f"Poi {ct} at {poi_x}, {poi_y} µm")
            prober.map.poi.add(poi_x, poi_y, f"poi_{ct}")


def main() -> None:
    prober = SentioProber.create_prober("tcpip", "127.0.0.1:35555")

    check_preconditions(prober)
    set_poi(prober)

    prober.select_module(Module.Wafermap)

    # Stepping loop:
    # - Step over all active dies. For each die step over all poi
    # - for this example we will NOT go into contact!
    prober.map.path.select_dies(TestSelection.All)
    prober.map.path.set_routing(RoutingStartPoint.UpperRight, RoutingPriority.ColBiDir)

    num_poi = prober.map.poi.get_num()
    prober.map.step_first_die()

    while True:
        # Variant 1: Step over all POI (comment Variant 2 to us this)
        selected_poi : range | list[str] = range(0, num_poi)

        # Variant 2: Step over a selection of POI
        selected_poi = [ 'poi_1', 'poi_5', 'poi_9']

        # Do the poi stepping
        for i in selected_poi:
            prober.map.poi.step(i)

        # Step to the next die
        prober.map.step_next_die()
        if prober.map.end_of_route():
            break


if __name__ == "__main__":
    main()