Package with mold-embedded inductor and method of fabrication therefor
A semiconductor device package may include a package substrate, mold material formed over the package substrate, and a mold-embedded inductor that is embedded in the mold material. The mold-embedded inductor may be coupled to a die, such as a power management integrated circuit die, which may also be embedded in the mold material. The mold-embedded inductor may be formed by forming conductive traces and an inductor core in the mold material. For example, an active mold packaging (AMP) process and corresponding laser direct structuring (LDS) processes may be performed to form openings in the mold material and to activate surfaces of the mold material to facilitate subsequent plating of conductive material. Activated surfaces of the mold material may have micro-rough texture and may include bulk conductive material formed via the application of laser energy to additives in the mold material during the LDS process(es).
1 . A method of forming a semiconductor device package, the method comprising:
providing a package substrate;
forming first mold material over the package substrate; and
forming an inductor having an inductor core that is embedded in the first mold material and having an inductor winding that is at least partially embedded in the first mold material, wherein the inductor core and at least a portion of the inductor winding are formed after forming the first mold material;
forming winding cavities and a core cavity in the first mold material via laser ablation;
while forming the winding cavities and the core cavity in the first mold material, activating first surfaces of the first mold material to form bulk conductive material via the laser ablation, wherein the first mold material comprises at least one laser-activatable additive configured to form the bulk conductive material in response to the laser ablation;
forming winding traces in the winding cavities, the inductor winding comprising the winding traces, wherein the winding traces are laterally adjacent to the core cavity,
forming conductive sidewalls in the core cavity, wherein forming the winding traces in the winding cavities and forming the conductive sidewalls in the core cavity are performed concurrently via electroless plating of the first surfaces of the first mold material activated via the laser ablation;
forming the inductor core in the core cavity by forming magnetic material on the conductive sidewalls via electroless plating;
forming second mold material over the first mold material, the winding traces, and the inductor core; and
performing additional laser ablation of the second mold material to:
form cavities in the second mold material that expose the winding traces; and
form bulk conductive material in second surfaces of the second mold material via activation of at least one additional laser-activatable additive in the second mold material.
2 . The method of claim 1 , further comprising:
forming topside winding traces via electroless plating of conductive material on the second surfaces of the second mold material, wherein the inductor winding includes the topside winding traces, and wherein the topside winding traces are formed at least partially in the cavities in the second mold material and at least partially overlapping the inductor core.
3 . The method of claim 2 , further comprising:
forming third mold material over the second mold material and over the topside winding traces.
4 . The method of claim 1 , wherein the laser ablation of the first surfaces of the first mold material and the additional laser ablation of the second surfaces of the second mold material respectively cause the first surfaces and the second surfaces to be micro-rough surfaces.
5 . The method of claim 1 , further comprising:
attaching solder balls to a bottom surface of the package substrate, opposite a top surface of the package substrate at which the inductor is formed.
6 . The method of claim 1 , further comprising:
before forming the first mold material over the package substrate, bonding an integrated circuit die to the package substrate, wherein the integrated circuit die is electrically coupled to bottom winding traces of the inductor.