Microelectronic assembly including columnar interconnections and method for forming same
DCFirst Claim
1. A method for forming a microelectronic assembly including an integrated circuit component attached to a substrate by columnar interconnections, the method comprising:
- depositing metallic columns onto component bond pads disposed on an integrated circuit component, each said metallic column comprising a solder attachment surface remote from the component bond pad and a peripheral surface intermediate the solder attachment surface and the component bond pad, each said metallic column formed of a first metal having a first melting temperature;
depositing a solder plate onto each solder attachment surface, said solder plate being formed of a solder having a second melting temperature lower than the first melting temperature;
oxidizing the peripheral surfaces of the metallic columns to inhibit wetting by solder during reflow;
superposing the integrated circuit component onto a substrate such that each solder plate contacts a corresponding substrate bond pad on the substrate; and
reflowing the solder by heating at a temperature above the second melting temperature and below the first melting temperature to bond the metallic column to the substrate bond pad and thereby attach the integrated circuit component to the substrate.
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Accused Products
Abstract
A microelectronic assembly (10) is formed and includes an integrated circuit component (12) attached to a substrate (14). The integrated circuit component (12) includes metallic columns (24) formed on bond pads (16) on the component (12). A solder plate (30) is formed on each of the metallic columns (24). The integrated circuit component (12) is superposed onto a substrate (14). The substrate (14) includes substrate bond pads (32), and each metallic column (24) registers with a corresponding substrate bond pad (32) such that the solder plate (30) contacts the substrate bond pad (32) to form a preassembly. The preassembly is then heated to reflow the solder plate (30) to form a solder joint (34) between the integrated circuit component (12) and the substrate (14). The solder joint (34) is formed between the solder attachment surface (28) of the metallic column (24) and the substrate bond pad (32).
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Citations
14 Claims
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1. A method for forming a microelectronic assembly including an integrated circuit component attached to a substrate by columnar interconnections, the method comprising:
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depositing metallic columns onto component bond pads disposed on an integrated circuit component, each said metallic column comprising a solder attachment surface remote from the component bond pad and a peripheral surface intermediate the solder attachment surface and the component bond pad, each said metallic column formed of a first metal having a first melting temperature; depositing a solder plate onto each solder attachment surface, said solder plate being formed of a solder having a second melting temperature lower than the first melting temperature; oxidizing the peripheral surfaces of the metallic columns to inhibit wetting by solder during reflow; superposing the integrated circuit component onto a substrate such that each solder plate contacts a corresponding substrate bond pad on the substrate; and reflowing the solder by heating at a temperature above the second melting temperature and below the first melting temperature to bond the metallic column to the substrate bond pad and thereby attach the integrated circuit component to the substrate. - View Dependent Claims (2, 3)
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4. A method for forming a microelectronic assembly including an integrated circuit component attached to a substrate by columnar interconnections, the method comprising:
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fabricating an integrated circuit component comprising a plurality of component bond pads; plating a first metal having a first melting temperature onto the component bond pads to form metallic columns, each said metallic column having a solder attachment surface remote from the face and a peripheral surface intermediate the component bond pad and the solder attachment surface; plating a solder plate onto each solder attachment surface, said solder plate being formed of a solder alloy having a second melting temperature lower than the first melting temperature; oxidizing the peripheral surfaces of the metallic columns, said solder plate protecting the solder attachment surfaces from oxidation; superposing the integrated circuit component onto a substrate including a plurality of substrate bond pads formed of a solder-wettable metal, such that each solder plate contacts a corresponding substrate bond pad; and reflowing the solder plate by heating at a temperature above the second melting temperature and below the first melting temperature to melt the solder alloy and thereafter cooling to resolidify the solder alloy to thereby join the metallic column to the substrate bond pad and attach the integrated circuit component to the substrate. - View Dependent Claims (5, 6, 7, 8, 9, 10)
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11. A method for forming a microelectronic assembly including an integrated circuit component attached to a substrate by a plurality of columnar interconnections, the method comprising:
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fabricating an integrated circuit component, said integrated circuit component having a face and a plurality of component bond pads formed on the face; depositing a polymeric layer onto the face, the polymeric layer comprising a plurality of openings that expose the component bond pads; electroplating copper metal onto the exposed component bond pad within the openings to form metallic columns, each said metallic column having a peripheral surface and a solder attachment surface; electroplating a tin-base solder onto the solder attachment surface within the opening to form a solder plate; removing the polymeric layer on the active face; oxidizing the peripheral surfaces to form a solder-nonwettable oxidized surface, whereby the solder plate protects the solder attachment surface from oxidization; superposing the integrated circuit component onto a substrate including a plurality of substrate bond pads formed of a solder-wettable metal, such that the solder plates contact each of the substrate bond pads; and heating at a temperature effective to melt the solder without melting the copper, whereupon the solder wets the solder attachment surface and the substrate bond pad, and thereafter cooling to resolidify the solder to form a solder joint bonding the metallic column and the substrate bond pad. - View Dependent Claims (12, 13, 14)
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Specification