Method of making a magnetic head

Claim 1

A method of manufacturing a bonded head assembly having an operative gap of predetermined depth comprising the steps of machining a first piece of magnetic material to form at least first and second channels therein, said channels being bounded by first, second and third raised areas with first, second and third planar surfaces, respectively, placing first and second shims onto said first and third surfaces, placing a mating piece of magnetic material across said first, second and third areas, said shims having a thickness such that said second surface is spaced from said mating piece by the desired gap depth, bonding said shims to said first piece and said mating piece, then filling said spacing between said second surface and said mating piece with a non-magnetic material, bonding said non-magnetic material to said second surface and said mating piece, and removing from said assembly said second channel portion.

Claim 2

A method of manufacturing a bonded head assembly having an operative gap of predetermined depth comprising the steps of machining a first piece of magnetic material to form at least first and second channels therein, said channels being bounded by first, second and third raised areas with first, second and third planar surfaces, respectively, placing first and second shims onto said first and third surfaces, placing a mating piece of magnetic material across said first, second and third areas, said shims having a thickness such that said second surface is spaced from said mating piece by the desired gap depth, bonding said shims to said first piece and said mating piece, then filling said spacing between said second surface and said mating piece with a non-magnetic material, bonding said non-magnetic material to said second surface and said mating piece, and removing from said assembly said second channel portion.

Claim 10

A method of manufacturing a pole piece pair for a bonded head assembly, said bonded pole piece pair having an operative gap of predetermined depth, comprising the steps of machining a first piece of ferrite to form a plurality of channels bounded by raised areas with planar surfaces, placing shims of the same composition as said first piece on the surfaces of at least two alternate raised areas, placing a mating piece of the same composition as said first piece across said channels upon said shims, sintering the assembly to form a unitary structure, said mating piece separated from each raised non-shimmed area by a depth of said shim equal to said predetermined depth to form the ultimately desired operative gap, then placing a glass rod adjacent each operative gap in an adjacent channel, heating said assembly until said glass rod softens and is drawn into said gap by capillary action, cooling said assembly until said glass hardens in position, cutting said unitary structure along each gap to form a plurality of glass bonded face assemblies, and cutting each glass bonded face assembly laterally to form a plurality of bonded pole piece pairs.

Claim 11

A method of manufacturing a pole piece pair for a bonded head assembly, said bonded pole piece pair having an operative gap of predetermined depth, comprising the steps of machining a first piece of ferrite to form a plurality of channels bounded by raised areas with planar surfaces, placing shims of the same composition as said first piece on the surfaces of at least two alternate raised areas, placing a mating piece of the same composition as said first piece across said channels upon said shims, sintering the assembly to form a unitary structure, said mating piece separated from each raised non-shimmed area by a depth of said shim equal to said predetermined depth to form the ultimately desired operative gap, then placing a glass rod adjacent each operative gap in an adjacent channel, heating said assembly until said glass rod softens and is drawn into said gap by capillary action, cooling said assembly until said glass hardens in position, cutting said unitary structure along each gap to form a plurality of glass bonded face assemblies, and cutting each glass bonded face assembly laterally to form a plurality of bonded pole piece pairs.