Thin film head slider fabrication process

Abstract

In an improved process for fabricating thin film head sliders from a wafer on one face of which a plurality of electromagnetic devices are arranged in rows, a single-row is mechanically processed to form sliders while it remains an integral part of the wafer, or after it is bonded to a fixture under a condition which induces no bow on the bar. Alternatively, double-row bar sliced from the wafer is used for fabrication of sliders, wherein each single-row bar is mechanically processed while it remains an integral part of the double-row bar, or after it is bonded to a fixture as an integral part of a double-row bar followed by severance of the bonded double-row bar into two single-row bars. The process eliminates or materially reduces any inducement of bow of the bar, which is a serious cause of throat height control problem associated with the prior fabrication methods.

What is claimed is: 
     
       1. A process for the fabrication of electromagnetic head assemblies from a bar on a first surface of which a plurality of electromagnetic devices are provided as a single row and with like orientation, the bar being integral along a second surface with an adjacent substrate portion, which fabrication process comprises the steps of: anchoring the .[.first surface.]. .Iadd.substrate portion .Iaddend.to a fixture,   while the .[.bar.]. .Iadd.substrate portion .Iaddend.is anchored.[.along the first surface.]. .Iadd., .Iaddend.forming head assemblies along .Iadd.a third surface of .Iaddend.the bar.Iadd., the third surface being opposed to the second surface; .Iaddend.and   separating the individual head assemblies.   
     
     
       2. The process defined in claim 1 wherein the adjacent substrate portion is anchored to a fixture with a side surface of the bar, which is opposed to the second surface, exposed .[.for said.]. .Iadd.to facilitate thereon .Iaddend.mechanical operations .Iadd.that form the head assemblies..Iaddend. 
     
     
       3. The process defined in claim 2 wherein the adjacent substrate is a wafer. 
     
     
       4. The process defined in claim 2 wherein the adjacent substrate is a second bar identical to the first bar. 
     
     
       5. The process defined in claim I further comprising the step of severing the bar from the adjacent substrate portion to expose the second surface of the bar for the mechanical operations. 
     
     
       6. The process defined in claim 5 wherein the adjacent substrate is a wafer. 
     
     
       7. The process defined in claim 5 wherein the adjacent substrate is a second bar identical to the first bar. 
     
     
       8. A process for the fabrication of electromagnetic head assemblies from a wafer comprising rows of electromagnetic devices formed thereon, each row and the underlying portion of the wafer being a bar of head assembly units, which fabrication process comprises the step of:   anchoring .[.the bar.]. at least a portion of the wafer to a fixture with a side surface .Iadd.of a bar.Iaddend.exposed, .Iadd.the water portion being thicker than the bar;.Iaddend.   while the .[.bar.]. .Iadd.wafer .Iaddend.is anchored, forming head assemblies along the side surfaces of the bar; and, severing the individual head assemblies from the wafer.   
     
     
       9. The process defined in claim 8 further comprising the steps of: removing the wafer from the fixture after the severing step,   anchoring the wafer to the fixture with a side surface of another bar exposed,   while the bar is anchored, forming head assemblies along the side surface of the bar,   severing the individual head assemblies from the wafer, and,   repeating the foregoing steps until all bars in the wafer have been processed.   
     
     
       10. The process defined in claim 8 wherein the wafer is anchored to a fixture followed by its severance from the fixture to expose a side surface of the bar for chanical operations. 
     
     
       11. The prooess deemed in claim 10 further comprising the steps of: anchoring the wafer to the fixture with a side surface of another bar exposed, and,   repeating all the steps of claim 9 until all bars in the wafer have been processed.   
     
     
       12. A process for manufacturing electromagnetic head assemblies from a fabricated wafer which contains on one surface electromagnetic devices arranged in rows in identical orientation, said process comprising the steps of: removing a part of the wafer to expose the surface on which the poles of the electromagnetic devices in a first row terminate,   fastening the wafer to a fixture in such a manner so that the exposed surface is susceptible to mechanical processing,   lapping and grinding the exposed surface so that a desired throat height of the poles and a desired contour of the row are attained,   parting the processed row into individual head assemblies, and,   removing the head assemblies from the remainder of the wafer by a slice cut, thereby generating a smaller wafer with an exposed surface on which the poles of the electromagnetic devices on a row adjacent to the first row terminate.   
     
     
       13. The process defined in claim 12 wherein the last three steps are repeated. 
     
     
       14. The process defined in claim 12 wherein the partial wafer is fastened to the future by bonding. 
     
     
       15. The process defined in claim 12 wherein the partial wafer is fastened to the fixture by clamping. 
     
     
       16. The process defined in claim 12 wherein the wafer is bonded to a lava substrate before it is fastened to the fixture via the lava substrate. and the lava substrate is debonded from the head assemblies formed as the last step of the process. 
     
     
       17. A process for manufacturing electromagnetic head assemblies from a fabricated wafer which contains on one surface electromagnetic devices arranged in rows in identical orientation. said process comprising the steps of: removing a part of the wafer to expose the surface of one row, which surface being distal from the poles of the electromagnetic devices on the row;   fastening the wafer to a future via the exposed surface of the row,   separating the remainder of the wafer from the row, thereby leaving exposed the surface of the row on which the poles terminate and generating a smaller wafer;   lapping and grinding the newly exposed surface of the row so that a desired throat height of the poles and a desired contour of the row are attained,   parting the processed row into head assemblies, and, removing the head assemblies from the fixture.   
     
     
       18. The process defined in claim 17 wherein the fastening step and all steps subsequent thereto are repeated. 
     
     
       19. A process for manufacturing electromagnetic head assemblies from a fabricated wafer which contains on one surface electromagnetic devices arranged in rows, the electromagnetic devices on a given row being in one orientation while those on the adjacent row being in an opposite orientation, said process comprising the steps of: slicing the wafer in such a manner to produce a plurality of identical double-row bars each having the poles of the electromagnetic devices on one row face those on the other row and further having two slice surfaces created by the slice, fastening one double-row bar onto a first fixture via a first slice surface and onto a second fixture via a second slice surface,   separating the fastened double-row bar into two identical fastened single-row bars by a slice cut to expose the surfaces of the two single-row bars on which the poles exterminate,   lapping and gnnding the exposed surface of the two single-row bar so that a desired throat height of the poles and a desired contour of the two single-row bars are attained,   parting the two processed single-row bars into head assemblies, and,   removing the head assemblies thus formed from the first and the second fixtures.   
     
     
       20. The process defined in claim 19 wherein there is a street between any two given adjacent rows of electromagnetic devices. 
     
     
       21. A process for manufactunng electromagnetic head assemblies from a fabricated wafer which contains on one surface electromagnetic devices arranged in rows, the electromagnetic devices on a given row being in one orientation while those on the adjacent row being in an opposite orientation, said process comprising the steps of: slicing the wafer in such a manner to produce a plurality of identical double-row bars each comprising a first and a second single-row bars, the first singlerow bar having the poles of the electromagnetic devices thereon distal from those on the second single-row bar and each single-row bar having a slice surface created by the slice;   fastening one double-row bar onto a first fixture via the slice surface of the first single-row bar with the slice surface of the second single-row bar remaining exposed,   lapping and grinding the exposed slice surface of the second single-row bar so that a desired throat height of the poles and a desired contour of the second single-row bar are attained,   fastening the double-row bar onto a second fixture via the processed slice surface of the second singlerow bar,   removing the first fixture from the processed second single-row bar, thereby exposing the slice surface of the first single-row bar;   lapping and grinding the newly exposed slice surface of the first single-row bar so that a desired throat height of the poles and a desired contour of the first single-row bar are attained.   transversely parting and longitudinally slicing the processed double-row bar into head assemblies, and,   removing the head assemblies from the second fixture.   
     
     
       22. The process defined in claim 21 wherein there is a street between any two given adjacent rows of electromagnetic devices.