Pre-solder bump preventive overcoating
AssigneeWestern Digital Technologies, Inc.
InventorsIrizo Naniwa, Kenichi Murata, Yuhsuke Matsumoto
Life of this patent
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Abstract
A hard disk drive flexure assembly includes an insulative base layer over a metal substrate, a first conductive layer over the base layer, a plurality of electrical pads each comprising a second conductive layer over the first conductive layer, a pre-formed bump of solder material positioned over each pad, and a conductive cover layer over at least a portion of each pre-solder bump. With the conductive cover layer, e.g., gold, solder material from each pre-solder bump is inhibited from transferring to a probe during electrical check of the flexure, the solder material is inhibited from oxidizing, and solder splash is inhibited. These techniques are especially relevant with narrow, high-density, small pitch electrical pads.
Claims19
A flexure for a suspension assembly for a hard disk drive (HDD), the flexure comprising:
- a metal substrate;
- an insulative base layer over at least a portion of the substrate;
- a first conductive layer over at least a portion of the base layer;
- a plurality of electrical pads, each electrical pad comprising a second conductive layer over the first conductive layer and configured for electrical connectivity with a corresponding electrical pad of a head slider;
- a pre-formed bump of solder material pre-positioned over at least a portion of each electrical pad of the plurality of electrical pads of the flexure;
- and
- a conductive cover layer over and in contact with the entire exposed portion of each pre-formed bump of solder material.
A method for manufacturing a flexure assembly for a hard disk drive, the method comprising:
- forming an insulative base layer over at least a portion of a metal substrate;
- forming a first conductive layer over at least a portion of the base layer;
- forming a plurality of electrical pads, each electrical pad comprising a second conductive layer over the first conductive layer and configured for electrical connectivity with a corresponding electrical pad of a head slider;
- forming a pre-formed bump of solder material pre-positioned over at least a portion of and in contact with each of the electrical pads of the plurality of electrical pads of the flexure assembly;
- and
- forming a conductive cover layer over the entire exposed portion of each pre-formed bump of solder material.
A hard disk drive (HDD) comprising:
- a disk medium rotatably mounted on a spindle;
- a suspension assembly comprising a flexure comprising:
- a metal substrate,
- an insulative base layer over at least a portion of the substrate,
- a copper layer over at least a portion of the base layer,
- a plurality of electrical pads, each electrical pad comprising a nickel layer over the copper layer,
- a pre-formed bump of solder material pre-positioned over at least a portion of each electrical pad of the plurality of electrical pads, and
- a gold cover layer over and in contact with the entire exposed portion of each pre-formed bump of solder material;
- a head slider housing a read-write transducer configured to read from and to write to the disk medium, the head slider mounted on the suspension assembly and electrically connected to the plurality of electrical pads of the flexure via the pre-formed bump of solder material;
- and
- means for moving the head slider to access portions of the disk medium.
Dependencies are inferred from the claim text.