Method of attaching a leadframe to singulated semiconductor dice
AssigneeMicron Technology, Inc.
InventorsTongbi Jiang, Syed S. Ahmad, Walter L. Moden
Life of this patent
Estimating the term…
Abstract
The present invention is directed to a method of attaching a leadframe to a singulated good die using a wet film adhesive applied in a predetermined pattern on the active surface of the good die, the lead finger of a leadframe, or both. By applying the adhesive only to identified good dice, time and material are saved over a process that applies adhesive to the entire wafer. By attaching the leadframe to the good die with a wet film, it is possible to remove the leadframe from the good die for rework if the good die subsequently tests unacceptable.
Claims44
A method of attaching at least one semiconductor die having an active surface thereon to at least one lead of a leadframe having a plurality of leads, comprising:
- providing a semiconductor wafer having a plurality of semiconductor die formed thereon;
- separating the plurality of semiconductor die formed on said semiconductor wafer, each semiconductor die of said plurality of semiconductor die having an active surface;
- identifying criteria for an acceptable semiconductor die of said plurality of semiconductor die;
- identifying an acceptable semiconductor die having said identifying criteria;
- applying an adhesive in a wet film state in the form of one of a liquid and a paste in a predetermined pattern to portions of the active surface of said acceptable semiconductor die;
- partially curing the adhesive from the wet film state to an intermediate tacky and flowable state while on portions of the active surface of said acceptable semiconductor die;
- removably attaching a portion of said at least one lead of the plurality of leads of the leadframe to a portion of the active surface of said acceptable semiconductor die using the intermediate partially cured tacky and flowable state of said adhesive;
- identifying additional criteria of said acceptable semiconductor die attached to the leadframe;
- testing said semiconductor die attached to said at least one lead of said plurality of leads of said leadframe to determine if the additional criteria are present in said semiconductor die;
- removing the at least one lead of said plurality of leads of said leadframe attached to said semiconductor die from said semiconductor die determined to be an unacceptable semiconductor die based on said testing;
- and
- reworking the unacceptable semiconductor die.
A method of attaching a semiconductor die having an active surface thereon to at least one lead of a leadframe having a plurality of leads, comprising:
- providing a semiconductor wafer having a plurality of semiconductor die thereon, each semiconductor die of said plurality of semiconductor die having an active surface;
- separating a semiconductor device from the semiconductor wafer;
- identifying criteria for an acceptable semiconductor die of said plurality of semiconductor die;
- testing said semiconductor die to determine if the criteria for an acceptable semiconductor die are included in said semiconductor die;
- applying an adhesive in a wet film state in the form of one of a liquid and a paste in a predetermined pattern to at least a portion of the active surface of more than one acceptable semiconductor die after the acceptable semiconductor die has been identified using said criteria;
- partially curing the adhesive from the wet film state to an intermediate tacky and flowable state;
- and
- removably attaching portions of the at least one lead of said plurality of leads of the leadframe to said acceptable semiconductor die using the intermediate tacky and flowable state partially cured adhesive.
A method of attaching a semiconductor die to a leadframe, comprising:
- providing a semiconductor wafer having a plurality of semiconductor die thereon, each semiconductor die of the plurality of semiconductor die having an active surface;
- separating the semiconductor die from a semiconductor wafer;
- identifying acceptable criteria of a semiconductor die;
- identifying an acceptable semiconductor die;
- applying a wet film adhesive in one of a liquid and a paste to portions of at least two lead fingers of the leadframe in a predetermined pattern;
- applying an adhesive in a wet film state in one of a liquid and a paste to portions of the active surface of the acceptable semiconductor die in a predetermined pattern;
- curing the adhesive on said at least two lead fingers of said leadframe and said acceptable semiconductor die active surface from the wet film state to an intermediate tacky and flowable state;
- and
- removably attaching the at least two lead fingers of said leadframe to the acceptable semiconductor die.
Dependencies are inferred from the claim text.