Method and apparatus for coupling a laser diode to a magnetic writer
A write head includes a cavity configured to couple a laser diode to the write head. A bottom of the cavity includes a heat conductive element configured to contact the laser diode, a plurality of thermal studs disposed below the heat conductive element, and a substrate disposed below the thermal studs. The heat conductive element, thermal studs, and substrate are thermally coupled to draw heat from the laser diode.
1. A method comprising:
forming, in order on a substrate, a thermal stud, a shield, an electrical insulation layer, and an electrode;
forming a sacrificial fill feature on the electrode;
depositing a fill layer around the sacrificial fill feature;
removing the sacrificial fill feature to define a cavity in the fill layer;
forming a solder bump on the electrode after removing the sacrificial fill feature; and
filling the cavity with a second sacrificial fill to protect the solder bump during subsequent processing.
2. The method of claim 1 , further comprising forming a mechanical stopper at a location corresponding to a bottom of the cavity before forming the sacrificial fill feature, wherein a first portion of the sacrificial fill feature encompasses the mechanical stopper.
3. The method of claim 2 , further comprising planarizing the fill layer to establish a reference surface that is defined by the mechanical stopper.
4. The method of claim 3 , further comprising forming a second portion of the sacrificial fill feature that covers the mechanical stopper.
5. The method of claim 3 , further comprising depositing optical layers on the reference surface, the optical layers comprising a waveguide core, and wherein a vertical spacing between the mechanical stopper and the waveguide core is defined by a process used to deposit the optical layers.
6. The method of claim 5 , further comprising:
forming a solder bump on the electrode after removing the sacrificial fill feature;
tacking a laser diode into the cavity, the laser diode comprising a solder pad configured to interface with the solder bump; and
performing a reflow operation that reshapes the solder bump so that the laser diode contacts the mechanical stopper and brings an output facet of the laser diode into alignment with the waveguide core.
7. The method of claim 6 , wherein the laser diode comprises an edge firing laser diode.
8. A method comprising:
forming, in order on a substrate, a thermal stud, a shield, an electrical insulation layer, and an electrode;
forming a sacrificial fill feature on the electrode;
depositing a fill layer around the sacrificial fill feature;
removing the sacrificial fill feature to define a cavity in the fill layer;
forming a second insulation layer over the electrode;
forming vias in the second insulation layer; and
forming a plurality of solder bumps on the electrode through the vias.
9. The method of claim 1 , wherein the thermal stud comprises an array of thermal studs, the method further comprising forming electrical pathways between individual ones of the array of thermal studs.
10. The method of claim 1 , wherein the fill layer comprises alumina.
11. A method comprising:
forming, in order on a substrate, a thermal stud, a shield, an electrical insulation layer, an electrode, and a mechanical stopper;
forming a sacrificial fill feature around the mechanical stopper;
depositing a fill layer around the sacrificial fill feature;
planarizing the fill layer to establish a reference surface that is defined by the mechanical stopper; and
removing the sacrificial fill feature to define a cavity in the fill layer.
12. The method of claim 11 , further comprising forming a second portion of the sacrificial fill feature that covers the mechanical stopper.
13. The method of claim 11 , further comprising depositing optical layers on the reference surface, the optical layers comprising a waveguide core, and wherein a vertical spacing between the mechanical stopper and the waveguide core is defined by a process used to deposit the optical layers.
14. The method of claim 13 , further comprising:
forming a solder bump on the electrode after removing the sacrificial fill feature;
tacking a laser diode into the cavity, the laser diode comprising solder pads configured to interface with the solder bump; and
performing a reflow operation that reshapes the solder bump so that the laser diode contacts the mechanical stopper and brings an output facet of the laser diode into alignment with the waveguide core.
15. The method of claim 14 , wherein the laser diode comprises an edge firing laser diode.
16. The method of claim 11 , further comprising:
forming a solder bump on the electrode after removing the sacrificial fill feature; and
filling the cavity with a second sacrificial fill to protect the solder bump during subsequent processing.
17. The method of claim 11 , wherein the thermal stud comprises an array of thermal studs, the method further comprising forming electrical pathways between individual ones of the array of thermal studs.
18. The method of claim 11 , further comprising, after removing the sacrificial fill feature:
forming a second insulation layer over the electrode;
forming vias in the second insulation layer; and
forming a plurality of solder bumps on the electrode through the vias.
19. The method of claim 11 , wherein the fill layer comprises alumina.