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US 7,604,727 B2Granted
Electroplating method for a semiconductor device
AssigneeRenesas Technology Corp.
InventorsMitsuru Kinoshita, Tsugihiko Hirano, Katsunori Takahashi
Life of this patent
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Abstract
An electroplating method calls for immersing a body to be plated in a plating solution containing tin and bismuth to form a tin-bismuth alloy skin layer on surfaces of the body. The plating is carried out such that a solid tin metal and a solid bismuth metal placed in the plating solution are connected to an anode and the body to be plated is connected to a cathode of a power supply.
Claims6
A method of manufacturing a semiconductor device, comprising steps of:
- (a) providing a plating apparatus having a plating vessel, a plating solution located in the plating vessel and containing both tin and bismuth, at least one metallic case having a first storage compartment, a second storage compartment neighboring the first storage compartment, a shielding plate disposed between the first storage compartment and the second storage compartment, a first opening for supplying a solid tin metal to the first storage compartment formed at a top of the first storage compartment of the metallic case, and a second opening for supplying a solid bismuth metal to the second storage compartment formed at a top of the second storage compartment of the metallic case, the first and second storage compartments have a front surface comprised of a mesh with a plurality of holes, the shielding plate has no holes, and the metallic case is located in the plating solution and connected to an anode of a power supply;
- (b) disposing the solid tin metal in the first storage compartment through the first opening, and disposing the solid bismuth metal in the second storage compartment through the second opening;
- (c) providing a lead frame having a plurality of product forming regions, the plurality of product forming regions each having plural leads;
- (d) mounting a plurality of semiconductor chips over the plurality of product forming regions, respectively;
- (e) forming a resin molding body for sealing the plurality of semiconductor chips such that a part of each of the plural leads is exposed from the resin molding body;
- (f) connecting the lead frame with the resin molding body to a cathode of the power supply, and disposing the lead frame with the resin molded body in the plating solution such that the lead frame opposes the front surface of each of the first and second storage compartments;
- and
- (g) forming a tin-bismuth alloy layer over the plural leads, which are exposed from the resin molding body, by activating the plating apparatus and conducting electrolysis between the anode and the cathode.
5 more elements
Dependencies are inferred from the claim text.