The WWF Wafer Map Format

This format was defined by Texas Instruments almost 20 years ago and is widely used not only by TI but by a number of manufacturers of test and assembly equipment.

Orientation

WWF wafer maps are always oriented with the FLAT or NOTCH down. Hence no parameter for the wafer flat location is needed. However if converting from a wafer map that has a flat on top, left or right, the data positions should be rotated as needed to produce output with the flat/notch down.

Reference Die

The reference die used to align the wafer on equipment is always assigned to the array position 0,0. You can see this in the sample below:

There are rules as to the location of the reference die. It is usually located in the lower right of the wafer; immediately to the right of the reference die there must be a "mirror" die -- essentially reflective metal that an automatic alignment camera can detect and use to then find the reference die.

Summary of WWF Keywords

Below you will find a summary of the keywords used in the WWF format:

Keyword	Required?	Notes
FACILITY	Yes	Fab Facility ID; up to 8 characters.
LOT	Yes	Lot ID - 7 numerals
DEVICE	Yes	FAB type device - 1-14 characters
WAFERS	NO	Number of Wafers
USER	NO	User string - up to 20 characters
PROBE_FACILITY	No	probe facility ID - up to 14 characters
X_SIZE	Yes	Die X dimension.
Y_SIZE	Yes	Die Y size
UOM	No	Units of Measure 2 to 4 characters
PIN_ONE	No	Pin One Orientation 3 numerals
BIN_NAME.bb	Yes	Bin bb type and Name. Alpha Numerical 1-16
STATUS	Yes	Status of Map; Alpha Numerical 1-4 chars
SCRIBE	Yes	wafer ID info - alpha numerical 1-8 chars
DIE_DESIGNATOR	No	Die Designator; alphanumeric 1-20 chars
WAFER_SIZE	Yes	Wafer Size in MM; Numeric 3 digits
LAYOUT	No	Wafer Layout Name; alphanumeric 1-14 chars
SHOT_MAP	No	Shot map coordinates. Alpha Numeric String. No limit
PLUG_MAP	No	Plug map coordinates. Alpha Numeric String. No limit
PARTIAL_MAP	No	partial (die) map coordinates. Alpha Numeric String. No limit
WAFER_ID.xx	Yes	Wafer ID. Must follow specific naming rules
FAB_ID.xx	No	Optional ID.
NUM_BINS.xx	Yes	Number of bins for wafer.xx. Numeric 2 digits.
BIN_COUNT.xx.bb	Yes	for wafer.xx number of die in bin.bb; Numeric, 2 digits.
MAP_XY.xx.bb	Yes	Wafer.xx map for bin.bb. AlphaNumeric String. No limit
END.	Yes	End of the Wafer Map File

Bin Classes

There are a number of different die types and these are placed into bins. The rules for which die types are assigned to which bins are summarized in the table below:

Bin Number	Category	Notes
01	GED (good electrical die)	A whole patterned die and probed. Inward of the EEZ (edge exclusion zone).
02-06	Multi-Bin or Outlier GED	A whole patterned die probed and located inside of the EEZ (edge exclusion zone).
07	Reserved	Do not create bin 07.
08	Plug Die	Whole Die used for Alignment or Test. Not in the EEZ.
09	Reject Die	Whole Die probed inward of the EEZ.
10	Edge Die	Whole or Partial Die. Touching or lying in the EEZ. Could also be a mirror die, alignment marker, test die, or Ghost die.
11-15	SWR Die	Whole patterned die; inward of EEZ and probed. May be a reference die.
16-17	Reserved	Do not generate any bin codes in this range.
18	Mirror Die	Mirror surfaced die positioned either completely or partially in the EEZ. Cannot be a reference die.
19	Ghost Die	located either completely or partially in the EEZ. Cannot be a reference die. Unpatterned.
19	Unbuildable Die	whole patterned die located inside of the EEZ. Can be a reference die. G required.

Header

FACILITY=OEMNAME               Facility ID
LOT=99XXX.1                    Lot ID
DEVICE=CMD252EUBMB4            Device ID
WAFERS=01                      Number of Wafers in this file
X_SIZE=123.228                 Die Size in X (units appear to be mils
Y_SIZE=123.228                 Die Size in Y (units appear to be mils
SCRIBE="BOTTOM,15,NTRL,FAB"    Location of scribed data?
WAFER_SIZE=150                 Wafer diameter in mm
STATUS="PROD"                  Status
USER="NOINK"                   User or user defined info
BIN_NAME.01="G,WQLPASS"        Bin category
BIN_NAME.09="WQLFAIL"         Bin category

This is followed by a section called a shot map. This appears to be a listing of all die - perhaps those present from the reticle shots. Notice that for each Y row (ranging from -21 to 20) there is a "list" of X locations.

SHOT_MAP="Y-21 12/31 Y-20 10/33 Y-19 9/34 Y-18 8/35 Y-17 7/36
Y-16 6/37 Y-15 5/38 Y-14 4/39 Y-13 3/40 Y-12 3/40 Y-11 2/41 Y-10 2/41 Y-9 1/42
Y-8 1/42 Y-7 1/42 Y-6 0/43 Y-5 0/43 Y-4 0/43 Y-3 0/19 24/43 Y-2 0/19 24/43
Y-1 1/19 24/42 Y0 1/19 24/42 Y1 1/42 Y2 1/42 Y3 1/42 Y4 1/42 Y5 1/42 Y6 1/42
Y7 2/41 Y8 2/41 Y9 3/40 Y10 3/40 Y11 4/39 Y12 5/38 Y13 5/38 Y14 6/37 Y15 7/36
Y16 8/35 Y17 10/33 Y18 11/32 Y19 13/30 Y20 16/27"

Now the wafer is identified, the number of bins is declared and a BIN (previously defined) referred to. That is followed by all the die positions belonging to this bin.

WAFERID.01=LG991-01-E4
NUM_BINS.01=02
BIN_COUNT.01.01=01313
MAP_XY.01.01="Y-21 12/18 20/28 30/31 Y-20 10/12 15/33 Y-19 9/34
Y-18 8/13 16/35 Y-17 7/13 16/22 24/27 29/35 Y-16 6/13 15/37 Y-15 5/8 10/13
16/31 33/37 Y-14 4/13 16/39 Y-13 4/13 16/26 28/40 Y-12 4/12 16/40 Y-11 2/5 7
9/12 16/41 Y-10 2/8 10/13 16 18/24 26/37 39/41 Y-9 1/13 16/42 Y-8 1/13 17/42
Y-7 2/13 17/25 27/42 Y-6 0/13 17/43 Y-5 0/13 18/43 Y-4 0/14 17/43 Y-3 0/7 9/14
17/19 24/43 Y-2 0/14 17 19 24/41 43 Y-1 1 3/5 7/11 13/17 19 26/29 31/42 Y0 2/10
17 36/42 Y1 1/11 23 27/31 38/42 Y2 1/2 4/10 14 19 21/22 24 26/42 Y3 1/2 4/10
12/21 23/32 35/42 Y4 1/2 4/14 16/19 21/29 31 33/42 Y5 1/2 4/42 Y6 1/2 4/17
19/23 25 27/42 Y7 2 4/25 27/41 Y8 2/17 19/41 Y9 4/40 Y10 4/13 15/18 20/23 25/29
31/36 38/40 Y11 4/31 33/39 Y12 5/12 14/38 Y13 5/25 27/38 Y14 6/16 18/37 Y15 7/9
11/29 31/34 36 Y16 8/16 18 20/27 29/35 Y17 10/33 Y18 11 13/29 31/32 Y19 13
15/21 23 25/30 Y20 16/19 21/24 26/27"

The next bin is enumerated followed by all the die positions belonging to this bin.

BIN_COUNT.01.09=00165
MAP_XY.01.09="Y-21 19 29 Y-20 13/14 Y-18 14/15 Y-17 14/15 23 28 36
Y-16 14 Y-15 9 14/15 32 38 Y-14 14/15 Y-13 3 14/15 27 Y-12 3 13/15 Y-11 6 8
13/15 Y-10 9 14/15 17 25 38 Y-9 14/15 Y-8 14/16 Y-7 1 14/16 26 Y-6 14/16
Y-5 14/17 Y-4 15/16 Y-3 8 15/16 Y-2 15/16 18 42 Y-1 2 6 12 18 24/25 30 Y0 1
11/16 18/19 24/35 Y1 12/22 24/26 32/37 Y2 3 11/13 15/18 20 23 25 Y3 3 11 22
33/34 Y4 3 15 20 30 32 Y5 3 Y6 3 18 24 26 Y7 3 26 Y8 18 Y9 3 Y10 3 14 19 24 30
37 Y11 32 Y12 13 Y13 26 Y14 17 Y15 10 30 35 Y16 17 19 28 Y18 12 30 Y19 14 22 24
Y20 20 25"

The file is closed with an END.

END.