ETCHED DIELECTRIC FILM IN HARD DISK DRIVES

• US 20070151661A1
• Filed: 03/12/2007
• Published: 07/05/2007
• Est. Priority Date: 07/18/2000
• Status: Abandoned Application

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Yang, Rui, Mao, Guoping
• Application Number:
  US11/685,065
• Publication Number:
  US 20070151661A1
• Time in Patent Office: Days
• US Class Current: 156/250
• CPC Class Codes: B32B 15/08 of synthetic resin
• CPC Class Codes: B32B 2311/00 Metals, their alloys or their compounds
• CPC Class Codes: B32B 2379/08 Polyimides
• CPC Class Codes: B32B 38/10 Removing layers, or parts of layers, mechanically or chemically
• CPC Class Codes: C08J 7/12 Chemical modification
• CPC Class Codes: C09K 13/02 containing an alkali metal hydroxide
• CPC Class Codes: G11B 5/484 Integrated arm assemblies, e.g. formed by material deposition or by etching from single piece of metal or by lamination of materials forming a single arm/suspension/head unit
• CPC Class Codes: G11B 5/486 with provision for mounting or arranging electrical conducting means or circuits on or along the arm assembly
• CPC Class Codes: H05K 1/028 Bending or folding regions of flexible printed circuits H05K1/0283 takes precedence
• CPC Class Codes: H05K 1/0393 Flexible materials H05K1/038 takes precedence; specific organic compositions are classified in H05K1/0313 and subgroups
• CPC Class Codes: H05K 1/056 the metal substrate being covered by an organic insulating layer
• CPC Class Codes: H05K 2201/0141 Liquid crystal polymer [LCP]
• CPC Class Codes: H05K 2201/0154 Polyimide
• CPC Class Codes: H05K 2201/0191 wherein the thickness of the dielectric plays an important role
• CPC Class Codes: H05K 2201/0397 Tab forming integral conductive tabs H05K3/4092
• CPC Class Codes: H05K 2201/09036 Recesses or grooves in insulating substrate recess in metallic substrate H05K2201/09745
• CPC Class Codes: H05K 2203/0353 Making conductive layer thin, e.g. by etching selective thinning for providing different thickness H05K2203/0369
• CPC Class Codes: H05K 2203/0786 Using an aqueous solution, e.g. for cleaning or during drilling of holes
• CPC Class Codes: H05K 2203/0793 Aqueous alkaline solution, e.g. for cleaning or etching
• CPC Class Codes: H05K 3/002 by liquid chemical etching
• CPC Class Codes: H05K 3/381 : by special treatment of the substrate
• CPC Class Codes: Y10T 156/1052 : with cutting, punching, tearing or severing
• CPC Class Codes: Y10T 428/12 : All metal or with adjacent metals

Abstract

An etched dielectric film for use in a hard disk drive. The dielectric film has a thickness of about 25 μm or greater when it is attached to a supporting metal substrate, and is subsequently etched to a thickness of about 20 μm or less.

Claims

1. A method comprising

providing a metal substrate,

attaching a dielectric film to said metal substrate, said dielectric film comprising a polymer selected from the group consisting of polyimides, liquid crystal polymers, and polycarbonates, said film having a thickness of about 25 μ

m or greater,

etching said dielectric film to a thickness of greater than 0 and less than about 20 μ

m.

2. A method according to claim 1 wherein the dielectric film is a polyimide having a carboxylic ester structural unit in the polymer backbone.

3. A method according to claim 1 wherein the dielectric film is attached to the metal substrate by an adhesive layer.

4. A method according to claim 1 wherein the dielectric film is a liquid crystal polymer attached to the metal substrate without an adhesive layer.

5. A method according to claim 3 wherein the dielectric film has been etched to a thickness of greater than 0 and less than about 10 μ

m.

6. A method according to claim 1 wherein the dielectric film is etched with an aqueous solution comprising

about 30 wt. % to about 55 wt. % of an alkali metal salt;

and

about 10wt. % to about 35wt. % of a solubilizer dissolved in said solution.

7. A method according to claim 1 wherein said alkali metal salt is selected from the group consisting of sodium hydroxide and potassium hydroxide.

8. A method according to claim 1 wherein said solubilizer is an amine.

9. A method according to claim 1 wherein said solubilizer is ethanolamine.

10. A method according to claim 1 wherein the etching is carried out at a temperature of about 50°

C. to about 120°

C.