Method for bonding substrates in an energy assisted magnetic recording head

A method for performing bonding of a laser substrate to a slider, the laser substrate including a first plurality of solder pads and a first alignment mark set, the slider including a second plurality of solder pads and a second alignment mark set, the method comprising:

• aligning the first alignment mark set on the laser substrate to the second alignment mark set on the slider to within 0.5 micron, the laser substrate including a first plurality of dots, the slider including a second plurality of dots configured to interlock with the first plurality of dots, the first alignment mark set being aligned with the second alignment mark set corresponding to the first plurality of dots being aligned with the second plurality of dots and the first plurality of solder pads being aligned with the second plurality of solder pads, the first alignment mark set including a first cross pattern, the second alignment mark set including a second cross pattern configured to interlock with the first cross pattern;
• locking the first plurality of dots with the second plurality of dots to form an interlocking key such that the laser substrate remains within a 0.5 micron tolerance with respect to the slider during a reflow step and such that the first plurality of dots is bonded with the second plurality of dots;
• and
• reflowing at least one of the first plurality of solder pads and the second plurality of solder pads, the interlocking key remaining substantially solid during the step of reflowing.