Method for forming wafer level package having serpentine-shaped electrode along scribe line and package formed
AssigneeIndustrial Technology Research Institute
InventorsMing Lu, Szu-Wei Lu
Life of this patent
Estimating the term…
Abstract
A method for forming wafer level package that has a serpentine-shaped electrode formed along a scribe line in-between two adjacent IC dies and the package formed are disclosed. In the method, each of the I/O redistribution lines connecting from an I/O redistribution pad is connected to a serpentine-shaped electrode for providing electrical communication during a subsequent electro-deposition process for forming a solder bump on the corresponding I/O redistribution pad. During a dicing operation of the wafer level package, a single cut through the center of the serpentine-shaped electrode can effect severance of all IC dies without possibility of any inter-die shorting or intra-die shorting.
Claims16
A method for forming wafer level package having serpentine-shaped electrode formed along a scribe line comprising the steps of:
- providing a wafer that is preprocessed with a plurality of IC dies formed on a top surface, each of said plurality of IC dies having a plurality of input/output (I/O) pads formed on top, each of said plurality of IC dies being spaced-apart from its immediate adjacent IC dies by a border that has at least a width of a scribe line;
- depositing a first metal layer on said top surface of the wafer and patterning into an I/O redistribution line with a first end in electrical communication with one of said plurality of I/O pads and a second end extending toward said border between said immediate adjacent IC dies, said patterning step further forms a serpentine-shaped electrode for a subsequent plating step on said border in electrical communication with said second end of the I/O redistribution line;
- depositing an insulating layer on said top surface of the wafer and forming an opening over an I/O redistribution pad exposing said first metal layer;
- depositing a photoresist layer to a thickness sufficient for forming a solder bump and forming an opening to expose said I/O redistribution pad;
- depositing a solder paste by a plating technique filling said opening to form a solder bump;
- and
- removing said photoresist layer and reflowing said solder bump into a solder ball.
A wafer level package having a serpentine-shaped electrode formed between each two of a plurality of IC dies comprising:
- a wafer that is preprocessed with a plurality of IC dies formed on a top surface, each of said plurality of IC dies having a plurality of input/output pads formed on top, each of said plurality of IC dies being spaced-apart from its immediate adjacent IC dies by a border that has at least a width of a scribe line;
- a plurality of I/O redistribution lines each having a first end in electrical communication with one of said plurality of I/O pads and a second end extending toward said border between the immediate adjacent IC dies;
- a serpentine-shaped electrode for use in a plating step positioned on said border having a multiplicity of leads each in electrical communication with one of said second end of the plurality of I/O redistribution lines;
- an insulating layer overlying the top surface of the wafer having openings over said I/O redistribution pads exposing said first metal layer;
- and
- a solder ball formed on each of said plurality of I/O redistribution pads.
Dependencies are inferred from the claim text.