Testing methods for magnetic heads and magnetic storage devices assembled with the magnetic heads

A manufacturing method for magnetic storage device assembled with one or more magnetic heads, the method comprising:

• preparing a substrate for forming a plurality of magnetic heads thereon;
• forming the plurality of magnetic heads on the substrate;
• assembling the plurality of magnetic heads into magnetic storage devices;
• testing at least some of the plurality of magnetic heads to obtain characteristic values;
• determining estimated characteristic values of non-tested magnetic heads on which testing is not performed using the characteristic values of the tested magnetic heads;
• classifying the non-tested magnetic heads based on the estimated characteristic values;
• assembling the magnetic heads classified as non-tested magnetic heads into the magnetic storage devices according to assembly rules;
• measuring performance of the magnetic storage devices assembled with the non-tested magnetic heads;
• and
• screening the magnetic storage devices assembled with the non-tested magnetic heads,
• wherein the characteristic values comprise at least one of:
• a resistance of a playback element of a magnetic head (MRDCR), an amplitude of a voltage output from terminals of a magnetic head due to a magnetic field received by the playback element (AMP), and an asymmetry of the voltage (ASYM).

A system, comprising:

• a processor adapted for executing logic;
• logic adapted for classifying each of a plurality of magnetic heads into one of:
• a first tested head class, and a non-test-candidate head class, such that at least two magnetic heads in each rowbar are classified into the first tested head class, each rowbar comprising a linear arrangement of a plurality of magnetic heads;
• logic adapted for determining characteristic values of the magnetic heads classified in the first tested head class via magnetic head testing;
• logic adapted for determining estimated characteristic values of the magnetic heads classified in the non-test-candidate head class, wherein the estimated characteristic values are based on the characteristic values of the magnetic heads classified in the first tested head class;
• logic adapted for classifying each of the magnetic heads classified in the non-test-candidate head class into one of:
• a second tested head class, and a non-test head class, wherein the classifying is based on the estimated characteristic values of the magnetic heads classified in the non-test-candidate head class;
• and
• logic adapted for determining characteristic values of the magnetic heads classified in the second tested head class via magnetic head testing.

A computer program product, the computer program product comprising:

• a non-transitory computer readable medium having computer readable code stored thereon, the computer readable medium comprising:
• computer readable code adapted for classifying each of a plurality of magnetic heads into one of:
• a first tested head class, and a non-test-candidate head class, such that at least two magnetic heads in each rowbar are classified into the first tested head class and remaining magnetic heads in each rowbar are classified into the non-test-candidate head class, each rowbar comprising a linear arrangement of a plurality of magnetic heads;
• computer readable code adapted for determining characteristic values of the magnetic heads classified in the first tested head class via magnetic head testing;
• computer readable code adapted for determining estimated characteristic values of the magnetic heads classified in the non-test-candidate head class, wherein the estimated characteristic values is based on the characteristic values of the magnetic heads classified in the first tested head class;
• computer readable code adapted for classifying each of the magnetic heads classified in the non-test-candidate head class into one of:
• a second tested head class, and a non-test head class, wherein the classifying is based on a comparison between the standard characteristic values and the estimated characteristic values of the magnetic heads classified in the non-test-candidate head class, such that any magnetic heads which do not have estimated characteristic values equivalent to or better than the standard values are classified into the second tested head class and remaining magnetic heads are classified into the non-test head class;
• and
• computer readable code adapted for determining characteristic values of the magnetic heads classified in the second tested head class via magnetic head testing.