Title (en)

LASER SURFACE TREATMENTS FOR MAGNETIC RECORDING MEDIA

Title (de)

OBERFLÄCHENBEHANDLUNG MITTELS LASERBESTRAHLUNG VON AUFNAHMETRÄGERN

Title (fr)

TRAITEMENTS DE SURFACE AU LASER POUR SUPPORTS D'ENREGISTREMENT MAGNETIQUES

Publication

EP 0853528 A4 20020130 (EN)

Application

EP 95931562 A 19950822

Priority

US 9510697 W 19950822

Abstract (en)

[origin: WO9707931A1] A surface treatment process employing pulsed laser energy enables selective texturizing and polishing of non-magnetizable substrate disks used in fabricating magnetic reading and recording disks (16). Substrate surfaces (44, 92, 100, 119) are texturized over dedicated head contact zones (32, 94, 104, 120, 128) to form multiple nodules (74, 98, 112) that are highly uniform to precisely control surface roughness. Laser polishing of data zones (36, 106, 122) causes localized flow of the substrate material, to remove the residual scratches of mechanical polishing without altering the non-magnetic character of the substrate at large. Between the data zones (36, 106, 122) and contact zones (32, 94, 104, 120, 128), transition zones (34, 108) can be formed by selectively graduating the nodule heights in the radial direction. The rounded structure of the nodules (74, 98, 112) increases surface resistance to intended or incidental transducing head contact. Removal of residual scratches enhances resistance to corrosion and improves signal quality, since subsequent layers, including the thin film recording layer and the protective carbon layer, tend to replicate the substrate surface topography.

IPC 1-7

G11B 5/64; G11B 5/84

IPC 8 full level

B24B 1/00 (2006.01); G11B 5/73 (2006.01); G11B 5/82 (2006.01); G11B 5/84 (2006.01); G02B 6/36 (2006.01)

CPC (source: EP US)

G11B 5/7368 (2019.04 - EP US); G11B 5/73913 (2019.04 - EP US); G11B 5/73919 (2019.04 - EP US); G11B 5/73921 (2019.04 - EP US); G11B 5/8404 (2013.01 - EP)

Citation (search report)

• [E] US 5496606 A 19960305 - MIZUKAMI MAKOTO [JP] & JP H04205916 A 19920728 - VICTOR COMPANY OF JAPAN
• [E] US 5560977 A 19961001 - YAMAMOTO YUZO [JP], et al & JP H076349 A 19950110 - KAO CORP
• [X] US 5388020 A 19950207 - NAKAMURA TAKAO [JP], et al
• [X] US 5202810 A 19930413 - NAKAMURA TAKAO [US], et al
• [X] US 5307593 A 19940503 - LUCKER JAMES A [US], et al
• [X] US 5437779 A 19950801 - SHIGE TOMOO [JP], et al
• [X] GB 2270412 A 19940309 - MITSUBISHI CHEM IND [JP]
• [X] GB 2274839 A 19940810 - KOBE STEEL LTD [JP]
• [X] WO 9101035 A1 19910124 - LEYBOLD AG [DE]
• [X] US 5364655 A 19941115 - NAKAMURA TAKAO [JP], et al
• [X] EP 0652554 A1 19950510 - IBM [US]
• [DA] EP 0447025 A1 19910918 - SEAGATE TECHNOLOGY [KY]
• [E] US 5506017 A 19960409 - RANJAN RAJIV Y [US], et al
• [E] US 5928759 A 19990727 - ARITA YOJI [JP], et al
• [E] US 5981902 A 19991109 - ARITA YOJI [JP], et al
• [E] EP 0779612 A1 19970618 - NGK INSULATORS LTD [JP]
• [E] US 5582878 A 19961210 - OGAWA SHIN-ICHI [JP], et al
• [E] PATENT ABSTRACTS OF JAPAN vol. 1997, no. 05 30 May 1997 (1997-05-30)
• [E] PATENT ABSTRACTS OF JAPAN vol. 1996, no. 10 31 October 1996 (1996-10-31)
• See references of WO 9707931A1

Designated contracting state (EPC)

DE GB

DOCDB simple family (publication)

WO 9707931 A1 19970306; EP 0853528 A1 19980722; EP 0853528 A4 20020130; EP 1271484 A2 20030102; EP 1271484 A3 20030326; JP 3199266 B2 20010813; JP H11500851 A 19990119

DOCDB simple family (application)

US 9510697 W 19950822; EP 02077006 A 19950822; EP 95931562 A 19950822; JP 53283996 A 19950822