Under bump metallurgy structural design for high reliability bumped packages
AssigneeMotorola, Inc.
InventorsVijay Sarihan, Owen Fay, Lizabeth Ann Keser
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Abstract
A method for creating an under bump metallization layer (37) is provided. In accordance with the method, a die (33) is provided which has a die pad (35) disposed thereon. A photo-definable polymer (51 or 71) is deposited on the die pad, and an aperture (66) is created in the photo-definable polymer. Finally, an under bump metallization layer (37) is deposited in the aperture. A die package is also provided comprising a die having a die pad (35) disposed thereon, and having an under bump metallization layer (37) disposed on the die pad. The structure has a depression or receptacle (57) therein and has a thickness of at least about 20 microns.
Claims46
A method for creating an under bump metallization, comprising the steps of:
- providing a die having a die pad disposed thereon;
- forming a layer of a first photo-definable polymer over the die pad;
- masking and exposing the first polymer to create an aperture therein which exposes the die pad;
- forming a bus metal layer over the first polymer and within the aperture;
- forming a layer of a second photo-definable polymer over the bus metal layer;
- masking and exposing the second polymer to create a first region in which the bus metal layer is exposed and a second region in which the bus metal layer is covered by the second polymer, the first region including at least a portion of the aperture;
- and
- forming an under bump metallization on the bus metal layer in the first region.
A method for creating an under bump metallization, comprising the steps of:
- providing a die having a die pad disposed thereon;
- forming a bus metallization layer over the die pad;
- forming a photo-definable polymer on the die pad;
- masking and exposing the polymer to create an aperture which exposes at least a portion of the bus metallization layer;
- and
- forming an under bump metallization on the exposed portion of the bus metallization layer.
A die package, comprising:
- a die having a die pad disposed thereon;
- and
- an under bump metallization disposed on said die pad, said under bump metallization having a receptacle therein for receiving a solder composition and having a thickness of at least about 20 microns as measured along a line orthogonal to the bottom of said aperture.
A die package, comprising:
- a die having a die pad disposed thereon;
- and
- an under bump metallization structure disposed on said die pad, said structure comprising monolithic copper and forming a receptacle for receiving a solder ball;
- wherein said structure has a minimum layer thickness of at least about 45 microns.
A die package, comprising:
- a die having a die pad disposed thereon;
- and
- an under bump metallization structure disposed on said die pad for receiving a solder composition, said structure having a thickness of at least about 20 microns.
Dependencies are inferred from the claim text.