Flip chip bonding method and chip used therein
AssigneeChipbond Technology Corporation
InventorsFei-Jain Wu, Sheng-Jen Wu, Hsueh-Shun Yeh
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Abstract
In a bonding process of a flip chip bonding method, a chip is bonded to contact pads of a substrate by composite bumps which each includes a raiser, a UBM layer and a bonding layer. Before the bonding process, the surface of the bonding layer facing toward the substrate is referred to as a surface to be bonded. During the bonding process, the surface to be bonded is boned to the contact pad and become a bonding surface on the contact pad. The bonding surface has an area greater than that of the surface to be bonded so as to reduce electrical impedance between the chip and the substrate.
Claims5
A flip chip bonding method comprising the steps of:
- providing a substrate including a plurality of contact pads;
- providing a chip including a body, a plurality of bond pads, a protective layer and a plurality of composite bumps, the plurality of bond pads are disposed on the body, the protective layer is configured to cover a surface of the body and includes a plurality of openings, each of the plurality of openings is configured to expose one of the plurality of bond pads, each of the plurality of composite bumps is electrically connected to one of the plurality of bond pads and includes a raiser, a under bump metallization (UBM) layer and a bonding layer, the raiser is non-conductive and covered by the UBM layer, the UBM layer is electrically connected to the plurality of bond pads and covered by the bonding layer, the bonding layer is electrically connected to the UBM layer, the bonding layer located above the raiser has a surface to be bonded which faces toward the substrate, wherein the raiser of each of the plurality of composite bumps is disposed on one of the plurality of bond pads, is a rib extended in a direction parallel to the surface of the body and is across one of the plurality of openings;
- and
- performing a bonding process, the plurality of composite bumps of the chip are bonded to the plurality of contact pads of the substrate, the substrate and the chip are configured to be pressed to allow the surface to be bonded of the bonding layer of each of the plurality of composite bumps to contact one of the plurality of contact pads such that the bonding layer has a bonding surface on each of the plurality of contact pads, and an area of the bonding surface is greater than an area of the surface to be bonded.
Dependencies are inferred from the claim text.