Sealing glass for magnetic head and magnetic head using the same

THIS APPLICATION IS A U.S. NATIONAL PHASE APPLICATION OF PCT INTERNATIONAL APPLICATION PCT/JP00/04268. The present invention relates to a magnetic head suitable for recording/reproducing of great amounts of magnetic information on a magnetic recording medium, and further relates to a sealing glass for joining a pair of magnetic core halves configuring such a magnetic head. 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 % BO, 70 to 77 wt % PbO, 0.1 to 5 wt % of at least one of AlOand ZnO, and 0.1 to 3 wt % of at least one of NaO and KO as a front sealing glass and using glass having a composition of 3 to 9 wt % SiO, 11 to 17 wt % BO, 66 to 77 wt % PbO, and 3 to 15 wt % of at least one of AlOand ZnO as a back sealing glass, a high-performance magnetic head having a high strength can be provided in high yields.