The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 07, 2003
Filed:
Jun. 04, 2001
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
Because of its composition that is liable to be crystallized and therefore has a low strength, a conventional sealing glass for magnetic head has a problem in that in a manufacturing process for manufacturing a magnetic head having a narrow track width and a short gap length corresponding to the high-density recording in recent years with high accuracy, cracks are liable to be developed in a sealing glass portion by an impact caused in cutting and grinding a head chip. By using glass having a composition of 13 to 17 wt % SiO , 5 to 6.8 wt % B O , 70 to 77 wt % PbO, 0.1 to 5 wt % of at least one of Al O and ZnO, and 0.1 to 3 wt % of at least one of Na O and K O as a front sealing glass and using glass having a composition of 3 to 9 wt % SiO , 11 to 17 wt % B O , 66 to 77 wt % PbO, and 3 to 15 wt % of at least one of Al O and ZnO as a back sealing glass, a high-performance magnetic head having a high strength can be provided in high yields.