Method and apparatus for testing batch fabricated magnetic heads during manufacture utilizing a magnetic field generated by a current carrying conductor

Claim 2

A combination for testing a plurality of magnetic head elements, carried on a substrate, during manufacture and before final separation and processing, including: conductive means carried on said substrate; a signal source, connectable to the conductive means, for causing said conductive means to supply a magnetic field to intersect head elements associated with the conductive means; a signal monitor, connectable to each of saiD head elements, to sense as electric current the magnetic field intersecting the connected head element; interpretive means, associated with said signal monitor for comparing the electric current sensed by the signal monitor to an acceptable current; and indicating means, connected to said interpretive means for indicating when the comparison indicates that the monitored electric current bears a predetermined relationship to the acceptable current.

Claim 3

The combination of claim 1 wherein the conductive means are a number of electrically conductive strips carried on said substrate each separate from, and in close proximity to, a number of head elements associated with said strips.

Claim 4

In combination, apparatus for testing during manufacture magnetic read/write recording elements, formed in batches on a substrate, including: a source of electrical test signals; conductive means, on said substrate, connected to said source and operable by said electrical signals, for generating a magnetic field intersecting a plurality of said elements; monitoring apparatus, connected to a selected number of said plurality of elements intersected by said magnetic field, for receiving electrical signals generated by said magnetic field; and sensing apparatus, connected to said monitoring apparatus, for detecting and indicating when the electrical signals received by said monitoring apparatus varies relative to predetermined tolerances.

Claim 5

In combination, apparatus for testing during manufacture magnetic read/write recording elements, formed in batches on a substrate, including: a source of electrical test signals; conductive means, on said substrate, connected to said source and operable by said electrical signals, for generating a magnetic field intersecting a plurality of said elements; monitoring apparatus, connected to a selected number of said plurality of elements intersected by said magnetic field, for receiving electrical signals generated by said magnetic field; and sensing apparatus, connected to said monitoring apparatus, for detecting and indicating when the electrical signals received by said monitoring apparatus varies relative to predetermined tolerances.

Claim 6

The testing apparatus of claim 3 wherein the conductive means comprise material, additional to the recording elements, formed on the substrate by the same techniques as are the elements.

Claim 7

The testing apparatus of claim 4 wherein the conductive means further comprise a number of elongated strips each adjacent to a plurality of elements.

Claim 10

The method of claim 6 wherein the magnetic field is electrically generated.

Claim 11

The method of claim 7 wherein the field is generated from conductive material placed on the surface, in the vicinity of the magnetic material at the same time as conductive portions of the head.

Claim 12

A combination for testing a plurality of magnetic head element areas carried on a substrate, during manufacture and before final separation and processing, including: a conductive strip, carried on said substrate, in the vicinity of a number of head element areas; an input test signal source, connectable to the conductive strip, operable to cause said conductive strip to supply a varying magnetic field to intersect said number of head element areas; a signal monitor, operable when connected to one of said number of head element areas, to sense as electric current the magnetic field intersecting the connected head element area; means for connecting the signal monitor to each of the number of head element areas in turn; a nominal signal source, for supplying nominal reference signals; a comparator, associated with said signal monitor and nominal signal source, for comparing the electric current sensed by the signal monitor to the nominal reference signals; and indicating means, connected to the comparator for indicating when the comparison indicates that the monitored electric current bears a predetermined relationship to the nominal signals.

Claim 13

A combination for testing a plurality of magnetic head element areas carried on a substrate, during manufacture and before final separation and processing, including: a conductive strip, carried on said substrate, in the vicinity of a number of head element areas; an input test signal source, connectable to the conductive strip, operable to cause said conductive strip to supply a varying magnetic field to intersect said number of head element areas; a signal monitor, operable when connected to one of said number of head element areas, to sense as electric current the magnetic field intersecting the connected head element area; means for connecting the signal monitor to each of the number of head element areas in turn; a nominal signal source, for supplying nominal reference signals; a comparator, associated with said signal monitor and nominal signal source, for comparing the electric current sensed by the signal monitor to the nominal reference signals; and indicating means, connected to the comparator for indicating when the comparison indicates that the monitored electric current bears a predetermined relationship to the nominal signals.

Claim 14

In combination: a first set of batch-fabricated magnetic head eLements and a second set of associated conductive means in close proximity on a manufacturing base; a source of electrical signals connected to a selected one of said sets operable to generate a magnetic field for intersecting the other set; and signal monitoring apparatus connected to the other of said sets for monitoring magnetic fields intersecting said set.

Claim 15

In combination: a first set of batch-fabricated magnetic head eLements and a second set of associated conductive means in close proximity on a manufacturing base; a source of electrical signals connected to a selected one of said sets operable to generate a magnetic field for intersecting the other set; and signal monitoring apparatus connected to the other of said sets for monitoring magnetic fields intersecting said set.