Integrated circuit package including wire bonds
AssigneeAgere Systems Inc.
InventorsJoze Eura Antol, John William Osenbach, Ronald James Weachock
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Abstract
It has been found that integrated packages having dies with at least 10 bonding pads separated by a pitch of 65 μm or less are susceptible to corrosion upon wire bonding to these pads and subsequent encapsulation in a passivating material. In particular, crevices are potentially formed between the bonding wire and bonding pad that are not passivated and that promote corrosion. Avoidance of crevice formation through, for example, appropriately choosing the bonding pad and wire configuration substantially avoids such corrosion.
Claims15
A process for fabricating an integrated circuit package, said package comprising:
- 1) an integrated circuit die including a bonding pad array,
- 2) a substrate comprising electrical contact pads, and
- 3) electrical communication structures with pitch of 65 μm or less, said structures comprising an electrically conducting wire compression bonded to a bonding pad of said array and bonded to at least one of said contact pads;
- said process comprising:
- contacting said wire to said bonding pad,
- then applying a force such that said wire is compression bonded to said bonding pad, and
- then covering said die with a passivating material wherein:
- said bonding pad comprises aluminum deposited at least partially over a passivation structure,
- said bonding pad is surrounded by a partially overlaying passivation region, and
- the configuration of said bonding pad before applying said force is such that, after applying said force, crevice formation between said bonding pad and said wire is substantially avoided.
A method for fabricating a bond pad on an integrated circuit, the method comprising:
- providing a semiconductor substrate;
- forming a first passivation layer on the substrate, the first passivation layer having a bond-pad opening having a first width and a passivation structure located within the bond-pad opening such that the passivation structure has a second width smaller than the first width;
- overlaying the bond-pad opening, including the passivation structure, with a metal layer such that the top of the metal layer substantially follows the contours of the underlying bond-pad opening so as to form a depression in the metal layer;
- forming a second passivation layer on the substrate, the second passivation layer having a passivation region surrounding and partially overlaying the metal layer;
- and
- then bonding a wire terminated with a wire ball to the metal layer of the bond pad by placing the wire ball over the passivation structure and applying a force such that the wire is compression bonded to the metal layer of the bond pad, wherein the metal layer over the passivation structure distorts into the depression.
Dependencies are inferred from the claim text.