Method of forming gaps in magnetic heads

Claim 2

A process for forming a gap for a magnetic head comprising the steps of: sputter depositing a layer of nonmagnetic spacer material onto portions of the confronting surfaces of each of at least two substantially rigid magnetic members; sputter depositing a layer of bonding material onto each layer of spacer material and onto the remaining exposed portions of the confronting surfaces of said magnetic members said spacer material not being appreciably reactive with either said bonding material or said magnetic members; positioning the magnetic members so that the layers of spacer material confront each other and said layers of bonding material are contiguous along a first line in the region of said confronting surfaces not including said layers of spacer material and along a second line in the region of said confronting surfaces between said layers of spacer material, said members being disposed at an angle whose sine/tangent is essentially equal to the thicknesses of said layers of spacer material divided by the distance between said first and second lines; pressing said members together while maintaining said bonding material at a predetermined temperature to fuse portions of said layers of bonding material together and to displace bonding material from portions of the regions between the confronting surfaces to bring the confronting surfaces of said magnetic members into contiguous relation at the region of said first line and to bring the layers of spacer material into contiguous relation in the region of said second line; cooling the members to ambient temperature; and removing most of the members and spacer material from the region of the confronting surfaces thereof to form a gap having a predetermined gap height, whereby the gap has a gap length essentially equal to the combined thicknesses of said layers of spacer material, said spacer material being a nonmagnetic material which is not appreciably reactive with the magnetic members.

Claim 3

The process according to claim 1 wherein the thicknesses of each of said layers of spacer material is of the order of about 25 microinches, and the sine/tangent of said angle is of the order of 0.001.

Claim 4

The process according to claim 2 wherein said gap height is of the order of 0-2 mils.

Claim 5

The process according to claim 2 wherein said bonding material is glass and said spacer material is not appreciably reactive with glass.

Claim 6

The process according to claim 4 wherein said members are ferrite cores and said spacer material is selected from the group consisting of zirconium oxide and magnesium aluminate.

Claim 7

The process according to claim 1 wherein said bonding material is glass and said spacer material is not appreciably reactive with glass.

Claim 8

The process according to claim 6 wherein said members are ferrite cores and said spacer material is selected from the group consisting of zirconium oxide and magnesium aluminate.

Claim 9

The process according to claim 1 wherein said members are ferrite cores and said spacer material is selected from the group consisting of zirconium oxide and magnesium aluminate.

Claim 10

A process of forming a gap for a magnetic head comprising the steps of: sputter depositing a first layer of spacer material onto the end surface of a first leg of a substantially rigid C-core ferrite member; sputter depositing a second layer of spacer material onto a portion of a surface of a substantially rigid I-core ferrite member; sputter depositing a first layer of bonding glass onto the first layer of spacer material and onto the end surface of the second leg of said C-core ferrite member; sputter depositing a second layer of bonging glass onto the second layer of spacer material and onto the remaining portion of the surface of said I-core ferrite member, each of said layers being of essentially uniform thickness; positioning said members so that said layers of spacer material are in confronting relation and said first and second layers of bonding glass are contiguous along a first line adjacent one edge of said second leg of said C-core ferrite member and along a second line adjacent tne apex between the window and first leg of said C-core ferrite member whereby an angle is formed between said members whose sine/tangent is essentially equal to the thickness of said first and second layers of spacer material divided by the distance between said first and second lines; pressing the members together while simultaneously heating the layers of bonding glass to at least its softening temperature to fuse portions of the layers of bonding glass together and to extrude bonding glass from portions of the regions between said members; cooling the members to ambient temperature; and removing most of the first leg of said C-core ferrite member and the confronting portion of said I-core member to form a gap having a predetermined gap height, whereby said gap has a gap length determined by the thickness of said first and second layers of spacer material plus the gap height times the sine/tangent of said angle, said spacer material being a nonmagnetic material which is not appreciably reactive with ferrite or with glass and which has thermal expansion characteristics substantially similar to that of ferrite over the temperature range between said ambient temperature and the softening temperature of said glass.

Claim 11

A process of forming a gap for a magnetic head comprising the steps of: sputter depositing a first layer of spacer material onto the end surface of a first leg of a substantially rigid C-core ferrite member; sputter depositing a second layer of spacer material onto a portion of a surface of a substantially rigid I-core ferrite member; sputter depositing a first layer of bonding glass onto the first layer of spacer material and onto the end surface of the second leg of said C-core ferrite member; sputter depositing a second layer of bonging glass onto the second layer of spacer material and onto the remaining portion of the surface of said I-core ferrite member, each of said layers being of essentially uniform thickness; positioning said members so that said layers of spacer material are in confronting relation and said first and second layers of bonding glass are contiguous along a first line adjacent one edge of said second leg of said C-core ferrite member and along a second line adjacent tne apex between the window and first leg of said C-core ferrite member whereby an angle is formed between said members whose sine/tangent is essentially equal to the thickness of said first and second layers of spacer material divided by the distance between said first and second lines; pressing the members together while simultaneously heating the layers of bonding glass to at least its softening temperature to fuse portions of the layers of bonding glass together and to extrude bonding glass from portions of the regions between said members; cooling the members to ambient temperature; and removing most of the first leg of said C-core ferrite member and the confronting portion of said I-core member to form a gap having a predetermined gap height, whereby said gap has a gap length determined by the thickness of said first and second layers of spacer material plus the gap height times the sine/tangent of said angle, said spacer material being a nonmagnetic material which is not appreciably reactive with ferrite or with glass and which has thermal expansion characteristics substantially similar to that of ferrite over the temperature range between said ambient temperature and the softening temperature of said glass.

Claim 12

The process according to claim 9 wherein the thicknesses of each of said layers of spacer material is of the order of about 25 microinches, and the sine/tangent of said angle is of the order of 0.001.

Claim 13

The process according to claim 10 wherein said gap height is of the order of 0-2 mils.

Claim 14

The process according to claim 10 wherein said spacer material is selected from the group consisting of zirconium oxide and magnesium aluminate.

Claim 15

The process according to claim 9, wherein said spacer material is selected from the group consisting of zirconium oxide and magnesium aluminate.