Selective wire coating during wire bonding
AssigneeWestern Digital Technologies, Inc.
InventorsDarryl Wong Jun Chen, Jiun Dong Loeh, Muhammad Farhan Taufiq Mohamad Helmi
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Abstract
A semiconductor device wherein a selected subset of bond wires is coated with an electrically insulating polymer to reduce occurrences of electrical shorts caused by wire sweep in the flow of a molding compound during an encapsulation stage of the manufacturing process. In some examples, the bond wires to be coated are selected based on a set of criteria that flag the bond wires exhibiting a relatively high tendency towards forming such electrical shorts. A specialized wire-bonding tool that can be operated to produce both polymer-coated bond wires and bare bond wires is also provided.
Claims20
A wire-bonding tool, comprising:
- a capillary portion including an approximately cylindrical body having a longitudinal center channel configured to deliver a bond wire to a first end of the approximately cylindrical body from an opposite second end thereof and further having a circumferential channel configured to deliver a fluid polymer from an inlet port thereof to the first end of the approximately cylindrical body;
- and
- a polymer-dispensing device connected to the inlet port and operable to controllably dispense volumes of the fluid polymer into the inlet port,
- wherein the circumferential channel includes a cylindrical-sheet channel configured to coat a segment of a selected bond wire exiting the first end of the approximately cylindrical body with a layer of the fluid polymer.
A method for assembling a semiconductor device, the method comprising:
- bonding segments of a bond wire between a vertical stack of semiconductor dies and a first main surface of a substrate, the segments of the bond wire providing electrical connections between the semiconductor dies and the substrate, the vertical stack being supported on the first main surface of the substrate and having the semiconductor dies thereof horizontally offset with respect to one another;
- coating a selected subset of the segments of the bond wire with an electrically insulating polymer;
- and
- encapsulating, with a molding compound, the vertical stack of semiconductor dies, the segments of the bond wire attached between the vertical stack of semiconductor dies and the first main surface of the substrate, and at least a portion of the first main surface of the substrate.
A semiconductor device, comprising:
- a substrate having a first main surface and an opposing second main surface;
- one or more semiconductor dies attached to the first main surface;
- a plurality of bond wires electrically connecting at least one of the one or more semiconductor dies to the first main surface of the substrate, wherein one or more of the plurality of bond wires have been selectively coated with a polymer;
- and
- a molding compound encapsulating the one or more semiconductor dies, the plurality of bond wires, and at least a portion of the first main surface of the substrate.
Dependencies are inferred from the claim text.