Flexure of disk drive suspension, and method of manufacturing conductive circuit portion of flexure

Patent metadata

Field	Value
Publication number	US-9679592-B2
Application number	US-201615215337-A
Country	US
Kind code	B2
Filing date	Jul 20, 2016
Priority date	Sep 10, 2015
Publication date	Jun 13, 2017
Grant date	Jun 13, 2017

Abstract

A suspension includes a load beam and a flexure. The flexure has a metal base and a conductive circuit portion. The conductive circuit portion has an insulating layer formed on the metal base, and a conductor formed on the insulating layer. The conductive circuit portion includes a first region which constitutes a part of the conductive circuit portion in the longitudinal direction, and a second region which constitutes another part of the same in the longitudinal direction. The conductor includes a thin conductor portion having a first thickness arranged in the first region, and a thick conductor portion having a second thickness arranged in the second region. The second thickness is greater than the first thickness.

First claim

What is claimed is:

1. A flexure mounted on a load beam of a disk drive suspension, the flexure comprising:
a metal base formed of a stainless-steel plate; and
a conductive circuit portion arranged along the metal base,
the conductive circuit portion comprising:
an insulating layer formed of an electrically insulating material and formed on the metal base; and
a conductor formed on the insulating layer,

the conductor comprising:
a thin conductor portion formed in a first region which constitutes a part of the conductive circuit portion in a longitudinal direction; and
a thick conductor portion formed in a second region which constitutes another part of the conductive circuit portion in the longitudinal direction, a thickness of the thick conductor portion being greater than that of the thin conductor portion,

wherein:
the flexure comprises a gimbal portion comprising a tongue; and
the conductive circuit portion includes an unsupported conductive circuit portion without a metal base which is arranged along the tongue, the unsupported conductive circuit portion comprising the thin conductor portion.

2. The flexure of claim 1 , wherein:
the flexure comprises a flexure tail portion;
the flexure tail portion comprises:
an opening formed in the metal base;
a bent portion of the metal base which is bent in a thickness direction at the opening; and
a trace curved portion which is curved in the thickness direction at a position facing the opening; and

the trace curved portion comprises the thick conductor portion.

3. The flexure of claim 1 , wherein:
the conductor comprises a terminal portion which is connected to a terminal of an electronic circuit; and
the terminal portion comprises the thick conductor portion.

4. The flexure of claim 1 , wherein:
the conductive circuit portion comprises a plurality of conductors formed on the insulating layer and arranged to be spaced apart from each other in a width direction of the conductive circuit portion; and
the plurality of conductors comprise:
thin conductor portions formed in a part of the conductors, the thin conductor portions being formed in a region which constitutes the part of the conductive circuit portion in the longitudinal direction; and
thick conductor portions formed in a remainder of the conductors, the thick conductor portions being formed in a region which constitutes the another part of the conductive circuit portion in the longitudinal direction, a thickness of each of the thick conductor portions being greater than that of each of the thin conductor portions.

5. A method of manufacturing a conductive circuit portion of a flexure, the flexure comprising a metal base, the conductive circuit portion comprising an insulating layer formed on the metal base, and a conductor formed on the insulating layer, the conductor comprising a thin conductor portion formed in a part of the conductor in a longitudinal direction, and a thick conductor portion formed in another part of the conductor in the longitudinal direction, the method of manufacturing the conductive circuit portion comprising:
a first masking process of forming a first resist, a height of the first resist corresponding to a thickness of the thick conductor portion, on the insulating layer, thereby forming a masking portion which is covered by the first resist, and a thin conductor formation space and a thick conductor formation space which are not covered by the first resist;
a first plating process of plating each of the thin conductor formation space and the thick conductor formation space with copper up to a thickness of the thin conductor portion, thereby forming a plated layer having a first thickness, which is shorter than the first resist, within the thin conductor formation space and the thick conductor formation space;
a second masking process of filling an opening of the thin conductor formation space with a second resist, thereby covering the plated layer within the thin conductor formation space;
a second plating process of forming an additional plated layer having a second thickness for the thick conductor portion on the plated layer within the thick conductor formation space, after the second masking process; and
a process of removing the first resist and the second resist after the second plating process.

6. A flexure mounted on a load beam of a disk drive suspension, the flexure comprising:
a metal base formed of a stainless-steel plate; and
a conductive circuit portion arranged along the metal base,
the conductive circuit portion comprising:
an insulating layer formed of an electrically insulating material and formed on the metal base; and
a conductor formed on the insulating layer,

the conductor comprising:
a thin conductor portion formed in a first region which constitutes a part of the conductive circuit portion in a longitudinal direction; and
a thick conductor portion formed in a second region which constitutes another part of the conductive circuit portion in the longitudinal direction, a thickness of the thick conductor portion being greater than that of the thin conductor portion,

wherein:
the load beam comprises a pair of hinge portions; and
the conductive circuit portion includes a flexible conductive circuit portion arranged between the hinge portions, the flexible conductive circuit portion comprising the thin conductor portion.

Assignees

• Nhk Spring Co Ltd

Inventors

• Kawao Sei

Classifications

• H05K1/056

  the metal substrate being covered by an organic insulating layer · CPC title

• H05K3/18

  using precipitation techniques to apply the conductive material · CPC title

• G11B5/486 Primary

  with provision for mounting or arranging electrical conducting means or circuits on or along the arm assembly · CPC title

• G11B5/4826 Primary

  Mounting, aligning or attachment of the transducer head relative to the arm assembly, e.g. slider holding members, gimbals, adhesive (G11B5/484 takes precedence; details of head housings or structures G11B5/10, G11B5/127; adjustment relative to the record carrier G11B5/56) · CPC title

• H05K1/028

  Bending or folding regions of flexible printed circuits (H05K1/0283 takes precedence) · CPC title