Methods of lapping a substrate while heating at least a portion of the substrate, and related substrates and systems

A method of lapping a row bar having a plurality of sliders, wherein the method comprises:

• a) providing the row bar having a plurality of sliders, wherein at least one slider comprises a transducer region comprising:
• at least a first transducer device, a second transducer device, and one or more heat-generating devices;
• b) applying a current to the one or more heat-generating devices in the transducer region to generate heat and cause at least the first transducer device and the second transducer device to expand in the lapping direction toward a lapping plate, wherein the current is controlled to cause the first transducer device to expand in the lapping direction toward the lapping plate by an amount greater than the second transducer device expands in the lapping direction toward the lapping plate;
• c) lapping the row bar while applying the current to the one or more heat-generating devices;
• d) reducing the current applied to the one or more heat-generating devices while lapping the row bar so that the first transducer device cools and recedes to a first receded distance in the lapping direction away from the lapping plate and the second transducer device cools and recedes to a second receded distance in the lapping direction away from the lapping plate, wherein the first transducer device recedes by an amount greater than the second transducer device;
• and
• e) lapping the row bar while the current is reduced at least until the first transducer device is at a third receded distance in the lapping direction away from the lapping plate and the second transducer device is at a fourth receded distance in the lapping direction away from the lapping plate, wherein the fourth receded distance is less than the second receded distance.

A lapping system comprising:

• a) a mounting structure that can removably couple a row bar, wherein the row bar comprises a plurality sliders, wherein at least one slider to be lapped comprises a transducer region comprising:
• at least a first transducer device, a second transducer device, and one or more heat-generating devices;
• b) a lapping plate having a lapping surface that is operable to rotate and contact the row bar to remove material from the row bar while the lapping plate rotates and contacts the row bar;
• and
• c) a controller comprising program instructions comprising:
• i) apply a current to the one or more heat-generating devices in the transducer region to generate heat and cause at least the first transducer device and the second transducer device to expand in the lapping direction toward the lapping plate, wherein the current is controlled to cause the first transducer device to expand in the lapping direction toward the lapping plate by an amount greater than the second transducer device expands in the lapping direction toward the lapping plate;
• ii) lap the row bar while applying the current to the one or more heat-generating devices;
• iii) reduce the current applied to the one or more heat-generating devices so that the first transducer device cools and recedes to a first receded distance in the lapping direction away from the lapping plate and the second transducer device cools and recedes to a second receded distance in the lapping direction away from the lapping plate, wherein the first transducer device recedes by an amount greater than the second transducer device;
• and
• iv) lap the row bar while the current is reduced at least until the first transducer device is at a third receded distance in the lapping direction away from the lapping plate and the second transducer device is at a fourth receded distance in the lapping direction away from the lapping plate, wherein the fourth receded distance is less than the second receded distance;
• and
• d) a source of electrical current, where the source is electrically coupled to the row bar and the controller.