Method of forming bump
AssigneeAdvanced Semiconductor Engineering, Inc.
InventorsHo-Ming Tong, Chun-Chi Lee, Jen-Kuang Fang, Min-Lung Huang, Jau-Shoung Chen, Ching-Huei Su, Chao-Fu Weng, Yung-Chi Lee
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Abstract
A method of forming a bump on an active surface of a wafer is disclosed. The method of the invention forms an under ball metallurgy (UBM) onto the active surface of the wafer. Then, the UBM is partially removed until a portion of the active surface of the wafer is exposed. At least one conductive stud is bonded onto the non-removed UBM by wire bonding.
Claims38
A method of forming a bump on a wafer, wherein the wafer has an active surface, and the active surface is provided with a passivation layer and a bonding pad exposed by the passivation layer, the method comprising:
- forming an adhesive layer on the active surface of the wafer to cover the bonding pad and the passivation layer;
- forming a barrier layer on the adhesive layer;
- forming a wettable layer on the barrier layer;
- forming a photomask on the wettable layer by a photolithography process,
- wherein the photomask exposes a portion of the wettable layer;
- removing the exposed wettable and sequentially the barrier layer and the adhesive layer thereunder by etching, until the active surface of the wafer is exposed;
- removing the photomask;
- bonding a conductive stud onto the wettable layer, wherein the conductive stud is made of a material selected from tin/lead alloy, leadless alloy and pure tin;
- and
- performing a reflow process to form a ball-shaped bump.
A method of forming a bump on an active surface of a wafer, the method comprising:
- forming an under ball metallurgy (UBM) on the active surface of the wafer;
- forming a photomask on the UBM by photolithography to partially expose the UBM;
- removing the exposed portion of the UBM by etching, until the active surface of the wafer is exposed;
- removing the photomask;
- bonding a conductive stud onto the UBM;
- and
- performing a reflow process to form a ball-shaped bump.
A method of forming a bump on an active surface of a wafer, the method comprising:
- forming a UBM on the active surface of the wafer;
- partially removing the UBM, until the active surface of the wafer is exposed;
- and
- bonding a conductive stud onto the UBM.
A method of forming a bump on a UBM that has been formed on an active surface of a wafer, the method comprising:
- bonding a conductive stud on the UBM by wire bonding.
Dependencies are inferred from the claim text.