Silver-tin alloy solder bumps
AssigneeSamsung Electronics Co., Ltd.
InventorsNam-jung Hur, Yong-hwan Kwon, Jong-han Park
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Abstract
Silver-tin alloy solder bumps are fabricated by forming a masked underbump metallurgy layer on a microelectronic substrate, to define exposed portions of the underbump metallurgy layer, plating silver on the exposed portions of the underbump metallurgy, plating tin on the silver and reflowing to form silver-tin alloy solder bumps. Accordingly, silver-tin alloy is not plated. Rather, individual layers of silver and tin are plated, and then reflowed to form silver-tin alloy solder bumps.
Claims11
A solder bump structure for a microelectronic substrate, comprising:
- an underbump metallurgy layer on the microelectronic substrate;
- a first layer comprising silver on the underbump metallurgy layer, opposite the microelectronic substrate, wherein the first layer is between 9 μm and 11 μm thick;
- and
- a second layer comprising tin on the first layer, opposite the underbump metallurgy layer, wherein the second layer is between 38 μm and 42 μm thick.
A solder bump structure for a microelectronic substrate, comprising:
- an underbump metallurgy layer on the microelectronic substrate;
- a first layer consisting essentially of silver on the underbump metallurgy layer, opposite the microelectronic substrate, wherein the first layer is between 9 μm and 11 μm thick;
- and
- a second layer consisting essentially of tin on the first layer, opposite the underbump metallurgy layer, wherein the second layer is between 38 μm and 42 μm thick.
Dependencies are inferred from the claim text.