Process of fabricating flip chip interconnection structure
AssigneeNational Central University
InventorsCheng-Yi Liu, Shen-Jie Wang, Cheng-Heng Kao
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Abstract
In a process of fabricating flip chip interconnection, a UBM layer is deposited on an I/O pad of a chip. The UBM layer includes a nickel layer. On the UBM layer is formed a tin-containing solder material. The chip is mounted on a carrier substrate by alignment of the bonding pad with a contact pad of the carrier substrate. A reflow process is performed to respectively turn the tin-containing solder material to a tin-containing solder bump and form a composite intermetallic compound on the nickel layer of the UBM to prevent its spalling.
Claims6
A process of fabricating an interconnection structure suitable for flip chip bonding of an electronic chip to a carrier substrate, the chip including at least a bonding pad and the carrier substrate including at least a copper contact pad, the method comprising:
- forming an under bump metallization (UBM) layer on the bonding pad, wherein the UBM layer includes an adhesion layer and a first nickel layer;
- forming a tin-containing solder material on the UBM layer;
- bringing the copper contact pad of tile carrier substrate in proximity of the tin-containing solder material by aligning the bonding pad of the chip with the contact pad of the carrier substrate;
- and
- performing a reflow process to respectively turn the tin-containing solder material to a tin-containing solder bump and diffuse a part of the copper atoms from the copper contact pad of the carrier substrate, and form a composite intermetallic compound between the tin-containing solder bump and the first nickel layer by reaction between nickel, tin and copper.
Dependencies are inferred from the claim text.