US4816949A
Expired / Lapsed
US
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Magnetic head containing amorphous alloy and crystallizable glass
Assignee: Proterial Ltd
•
Filing: 1987-09-09
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Granted: 1989-03-28
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Expires: 2007-09-09
Abstract
Abstract The present invention relates to a magnetic head in which a magnetic metal film comprising a Co-containing amorphous alloy and a crystallizable glass of the PbO-B 2 O 3 -ZnO system as a solder glass are used. The magnetic head of the present invention has about 2 times higher recording density than the conventional one as a magnetic head for floppy disks and hard disks because an amorphous alloy is used. Since a crystallizable glass is used as the glass, there can be obtained a magnetic head having a high strength and superior humidity resistance and reliability.
Inventors
- 👤 Seiichi Yamada
- 👤 Takashi Naitoh
- 👤 Takashi Namekawa
- 👤 Akira Ikegami
- 👤 Ryoo Gotoo
- 👤 Toshikazu Nishiyama
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 06:47
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/127; G11B5/187; G11B5/23; G11B5/232; G11B5/147; Y; Y10; Y10T; Y10T428/00; Y10T428/11; Y10T428/1193
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
136 words
A magnetic head for a hard disk drive capable of being fixed to a ceramic slider, the head part being formed by bringing a pair of magnetic cores face to face so that a magnetic gap is provided at a portion of said magnetic head confronting a magnetic recording medium, and a place where the pair of magnetic cores are brought face to face comprises magnetic metal films joined to each other via a solder glass layer, each of said magnetic metal films comprising a Co-containing amorphous alloy, and said solder glass comprising a crystallizable glass of the PbO-B 2 O 3 -ZnO system having the following composition: ______________________________________
PbO 75˜85 wt %,
ZnO 5˜10 wt %,
B.sub.2 O.sub.3
7˜12 wt %,
SiO.sub.2 0.5˜2.0 wt %,
K.sub.2 O 0.5˜1.0 wt %,
CuO 0.5˜2.0 wt %.
______________________________________
Claim 2
Dependent Claim
136 words
A magnetic head for a hard disk drive capable of being fixed to a ceramic slider, the head part being formed by bringing a pair of magnetic cores face to face so that a magnetic gap is provided at a portion of said magnetic head confronting a magnetic recording medium, and a place where the pair of magnetic cores are brought face to face comprises magnetic metal films joined to each other via a solder glass layer, each of said magnetic metal films comprising a Co-containing amorphous alloy, and said solder glass comprising a crystallizable glass of the PbO-B 2 O 3 -ZnO system having the following composition: ______________________________________
PbO 75˜85 wt %,
ZnO 5˜10 wt %,
B.sub.2 O.sub.3
7˜12 wt %,
SiO.sub.2 0.5˜2.0 wt %,
K.sub.2 O 0.5˜1.0 wt %,
CuO 0.5˜2.0 wt %.
______________________________________
Claim 3
Dependent Claim
35 words
A magnetic head according to claim 1, wherein said magnetic head is fixed to said ceramic slider by another crystallizable glass having the same composition range as the solder glass for joining said magnetic metal.
Claim 4
Dependent Claim
27 words
A magnetic head according to claim 2, wherein said crystallizable glass has a thermal expansion coefficient of 90 to 110×10 -7 /°C. after it has been crystallized.
Claim 5
Dependent Claim
27 words
A magnetic head according to claim 1, wherein said crystallizable glass has a thermal expansion coefficient of 90 to 110×10 -7 /°C. after it has been crystallized.
Claim 6
Dependent Claim
25 words
A magnetic head according to claim 1, wherein said crystallizable glass has a crystallization initiating temperature in the range of 450° C. to 470° C.
Claim 7
Dependent Claim
23 words
A magnetic head according to claim 1, wherein said crystallizable glass has a viscosity of 10 4 poise or below at 460° C.
Claim 8
Dependent Claim
24 words
A magnetic head according to claim 1, wherein said crystallizable glass has a softening point in the range of 360° C. to 380° C.
Claim 9
Dependent Claim
39 words
A magnetic head according to claim 1, wherein said place where the pair of magnetic cores are brought face to face comprises magnetic metal films made of a Co-containing amorphous alloy and SiO 2 films laminated one after another.
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