Low Resistance Interface Metal For Disk Drive Suspension Component Grounding

Patent metadata

Field	Value
Publication number	US-2017298526-A1
Application number	US-201715444000-A
Country	US
Kind code	A1
Filing date	Feb 27, 2017
Priority date	Dec 16, 2009
Publication date	Oct 19, 2017
Grant date	—

Abstract

A stainless steel suspension component such as a mount plate is chemically activated by exposure to an activating solution. Gold is then spot plated onto the mount plate in the activated area using an elastomeric mask that is clamped over the mount plate. A component may then be bonded to the gold bond pads. The component may include a PZT microactuator bonded to the gold bond pads using a conductive adhesive such as silver epoxy. The gold acts as an interface metal that provides to a low resistance and environmentally robust ground path for the microactuator.

First claim

We claim:

1 . A method of forming a ground connection to a stainless steel suspension component, the method comprising:
chemically activating a stainless steel surface of the suspension component to produce a chemically activated surface of the suspension component; pressing a resilient plating mask against the suspension component, the resilient plating mask having an aperture therein that extends to the chemically activated surface of the suspension component, the portion of the suspension within the aperture defining a plating surface; causing a gold containing electrolyte to flow into the aperture of the resilient plating mask and thereby contact the plating surface; electroplating gold onto the plating surface exposed within the aperture of the resilient plating mask to create a spot gold plated portion of the suspension component; and bonding an electrical component to the spot gold plated portion.

2 . The method of claim 1 wherein:
the chemical activation is performed using a chemical activating solution comprising:
(i) 3 to 20% by weight of hydrochloric acid;
(ii) 2 to 30% by weight of sulfuric acid;
(iii) 0.1 to 5% by weight of a nonionic or cationic surface active agent; and
(iv) 0.1 to 20% by weight of 2-pyrrolidone or its N-alkyl derivative, and

the component comprises at least one of a suspension flexure circuit bond pad, a grounding wire, a flying lead, and a piezoelectric microactuator; and the method further comprises:
after the electroplating, heat treating the suspension component.

3 . The method of claim 1 wherein the electrical component is a wire.

4 . The method of claim 1 wherein the electrical component is a piezoelectric microactuator.

5 . The method of claim 1 wherein the bonding step comprises thermosonic bonding.

6 . The method of claim 1 further comprising heat treating the suspension component.

7 . The method of claim 1 wherein the suspension component is a suspension base plate.

8 . The method of claim 1 wherein the suspension component is a load beam.

9 . The method of claim 1 further comprising grounding the suspension component, and causing an electrical current to flow through the spot plated gold portion of the suspension component.

10 . A method of forming an electrical connection to a disk drive suspension body component, the method comprising:
chemically activating a flat surface of the suspension body component to produce a chemically activated flat surface of the suspension body component; isolating a portion of the suspension body component, and causing a gold plating solution to contact the isolated portion; locally spot plating gold onto the chemically activated flat surface, the spot plating producing a locally gold plated flat surface of the suspension body component; and bonding an electrical component to the locally gold plated flat surface.

11 . The method of claim 10 wherein the step of chemically activating comprises exposing the suspension component to an activating solution and subjecting the suspension component to cathode electrolytic activation.

12 . The method of claim 10 wherein:
the bonding step is selected from the group consisting of thermosonic bonding, brazing, soldering, and conductive adhesive adhering; and
the component is selected from the group consisting of a wire, a flexible circuit lead, and a microactuator.

13 . The method of claim 10 wherein the bonding step comprises adhering a microactuator to the suspension body component using a conductive adhesive.

14 . The method of claim 10 wherein the locally spot plating step is performed after the suspension body component has been separated from a sheet of metal from which a plurality of such suspension body components are fabricated.

15 . The method of claim 10 wherein:
the locally spot plating step is performed at a plurality of separate locations on a sheet of metal from which the suspension body component will be formed; and
the method further comprises after the locally spot plating step, stamping the sheet of metal and separating a plurality of suspension body components from the sheet of metal, each suspension body component having at least one location having gold locally spot plated thereon.

16 . The method of claim 10 wherein the step of locally spot plating gold comprises:
pressing a resilient plating mask against the chemically activated flat surface, the resilient plating mask having an aperture therein that extends to the chemically activated flat surface of the suspension body component, the portion of the suspension body component within the aperture defining a plating surface;
causing a gold containing electrolyte to flow into the aperture of the resilient plating mask and thereby contact the plating surface; and
electroplating gold onto the plating surface exposed within the aperture of the resilient plating mask to create a spot gold plated portion of the suspension body component.

17 . The method of claim 10 wherein the suspension body component is a mount plate, and the mount plate includes the locally gold plated flat surface.

18 . The method of claim 10 wherein the suspension body component is a load beam, and the load beam includes the locally gold plated flat surface.

19 . The method of claim 18 wherein the electrical component is a microactuator, whereby the microactuator is grounded through a gold plated surface of the load beam.

20 . A method of forming a ground connection from a stainless steel disk drive suspension body to a microactuator, the method comprising:
chemically activating a surface of the stainless steel disk drive suspension body; using a mask to isolate a portion of the stainless steel disk drive suspension body thereby defining an isolated portion of the stainless steel disk drive suspension body; causing a plating solution to contact the isolated portion; plating a corrosion resistant metal onto the isolated portion of the stainless steel disk drive suspension body, thereby forming a corrosion resistant plated area on the disk drive suspension body; mechanically and electrically bonding an electrode of the microactuator to the corrosion resistant plated area.

Assignees

• Magnecomp Corp

Inventors

• Lazatin Marcos
• Holaway Brett

Classifications

• C25D3/48 Primary

  of gold · CPC title

• C25D5/022

  using masking means · CPC title

• C25D5/50

  by heat-treatment · CPC title

• C25D7/0607

  Wires · CPC title

• C25D5/36

  of iron or steel · CPC title