Correcting current crowding in row bar and vias for single pad bonding

A method, comprising:

• positioning a wafer in a lapping system with a lapping controller, the wafer comprising:
• a plurality of sliders;
• a magnetoresistive (MR) element deposited at an air bearing surface (ABS) of each slider;
• one or more electronic lapping guides (ELGs) positioned at the ABS and electrically connected to the wafer, wherein the ELGs correspond to at least one of the plurality of sliders;
• a bonding pad electrically connected to each of the one or more ELGs;
• and
• one or more peripheral grounding vias electrically connected to the wafer;
• connecting the lapping controller with the wafer at the bonding pad and the peripheral grounding vias;
• delivering a current to at least one of the ELGs through the bonding pad, wherein no more than 20% of the one or more ELGs in the wafer receive a current at one time, and wherein the bonding pads and the peripheral grounding vias are electrically connected through the wafer;
• detecting a resistance at the ELGs which receive a current;
• adjusting lapping based on the resistance detected at the ELGs which receive a current, wherein the lapping is adjusted based on the resistance of the corresponding ELGs;
• lapping the ELGs based on the resistance detected to achieve a specific stripe height;
• and
• repeating the steps of delivering the current, detecting the resistance, adjusting the lapping and lapping the ELGs until each of the ELGs is lapped to a specific stripe height.

A system for lapping a wafer, the wafer comprising:

• a plurality of sliders, each slider comprising:
• a magnetoresistive (MR) element deposited at an air bearing surface (ABS) of the slider;
• an electronic lapping guide (ELG) positioned at the ABS and electrically connected to the wafer;
• and
• a bonding pad electrically connected to the ELG, wherein the wafer has one or more peripheral grounding vias formed therein;
• and
• the system comprising:
• a lapping system comprising a lapping controller and configured to simultaneously lap an air bearing surface on the plurality of sliders, wherein the wafer is configured to be mounted on the lapping system;
• and
• the lapping controller electrically coupled to the bonding pads and the peripheral grounding vias, the lapping controller configured to sequentially provide a current to the ELGs in groups of no more than 20% of the attached ELGs, measure the resistance of the ELGs using the current path, and provide instructions to the lapping system based on the measured resistance, wherein the lapping controller is also configured to provide current, measure resistance and provide instructions to the lapping system until each slider is lapped by the lapping system to a desired stripe height.