Browse Prior Art Database

Secure Die Picking of Known Good Die

IP.com Disclosure Number: IPCOM000117765D
Original Publication Date: 1996-May-01
Included in the Prior Art Database: 2005-Mar-31
Document File: 2 page(s) / 34K

Publishing Venue

IBM

Related People

Bourolleau, P: AUTHOR [+4]

Abstract

The purpose of the present disclosure is to secure picking operation of known good dies as a function of test results wafer mapping.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 94% of the total text.

Secure Die Picking of Known Good Die

      The purpose of the present disclosure is to secure picking
operation of known good dies as a function of test results wafer
mapping.

      At wafer test process step, a relation of a known good die (the
referenced die) is established with a physical dimension of the
wafer; i.e., the X and Y positions of some dies relative to the
center of the wafer.  These values are then added as usual to a
result file named test result wafer map that is generated for die
picking purpose.  Next, at die picking, the wafer map give known good
dies to be picked plus the X,Y position of the reference die relative
to wafer center.  At this step the wafer is diced and mounted on a
frame with streched tape (wafer expansion).  The die picker
automatically aligns the wafer as usual and calculates wafer center
position while it performs auto aligning.  Then, wafer map data are
used to go to the reference die.  At this step, picker software will
have to calculate x,y position for that die from wafer center then it
performs a comparison of this x,y with the X,Y position received from
the test file.

There is no mis-picking as long as:
  x,y = X,Y  k Index where
  k < 1/3 depending of die size and wafer expanding and
   Index = die index on picker.

      Note that x,y and X,Y are micron values of die center position
relatively to wafer center within same orthonormal quadrant.  The
values of x and y are calculated on picker prior die pi...