High frequency integrated point-of-load power converter with embedded inductor substrate
A low profile power converter structure is provide wherein volume is reduced and power density is increased to approach 1 KW/in 3 by at least one of forming an inductor as a body of magnetic material embedded in a substrate formed by a plurality of printed circuit board (PCB) lamina and forming inductor windings of PCB cladding and vias which may be of any desired number of turns and may include inversely coupled windings and which provide a lateral flux path, forming the body of magnetic material from high aspect ratio flakes of magnetic material which are aligned with the inductor magnetic field in an insulating organic binder and hot-pressed and providing a four-layer architecture comprising two layers of PCB lamina including the embedded body of magnetic material, a shield layer and an additional layer of PCB lamina, including cladding for supporting and connecting a switching circuit, a capacitor and the inductor.
1. A power converter comprising
a switching circuit,
a capacitor, and
an inductor formed of a body of magnetic material embedded in a laminated printed circuit board structure and windings formed by vias connected to areas of cladding on surfaces of said laminated printed circuit board structure, wherein said body of magnetic material is formed of flakes of magnetic material in an insulating binder.
2. A power converter as recited in claim 1 , wherein said flakes are oriented in alignment with a magnetic field in said inductor.
3. A power converter as recited in claim 1 , wherein said inductor is of the lateral flux type.
4. A power converter as recited in claim 1 , wherein windings of said inductor are formed by cladding on lamina of said laminated printed circuit board structure and vias in said laminated printed circuit board structure.
5. A power converter as recited in claim 1 , further including a shield layer and a further layer of laminated printed circuit board structure including cladding for supporting and connecting said switching circuit and said capacitor and forming input and output connections.
6. A power converter comprising
a switching circuit,
a capacitor, and
an inductor including a body of magnetic material comprised of a composite formed of flaked magnetic material that has been coated with SiO 2 and hot pressed with an organic binder, wherein said body of magnetic material is embedded in a substrate.
7. A power converter as recited in claim 6 , wherein a thickness of said flakes of magnetic material is approximately 1 μm and a lateral dimension of said flakes of magnetic material is approximately 100 μm.
8. A power converter as recited in claim 6 , wherein said substrate comprises lamina of a laminated printed circuit board structure.
9. A power converter as recited in claim 6 , wherein windings of said inductor are formed of cladding on said substrate and vias in said substrate.
10. A power converter as recited in claim 6 , wherein windings of said inductor are inversely coupled.
11. A power converter as recited in claim 6 , further including a shield layer and a further layer laminated to said substrate, said further layer including cladding for forming input and output connections to said power converter and connections to and between said switching circuit and said capacitor.
12. A power converter as recited in claim 6 , wherein said switching circuit comprises two transistors connected as a half-bridge.
13. A power converter as recited in claim 6 , wherein said capacitor is comprised of a plurality of capacitors connected in parallel.
14. A power converter having a multi-layer architecture, said multi-layer architecture comprising
one or more lower layers comprising an inductor core laminated between two printed circuit board layers, wherein said inductor core is formed of flakes of magnetic material in an insulating binder,
a shielding layer extending over said one or more lower layers, and
one or more upper layers comprising a further printed circuit board lamina with patterned cladding and supporting switching transistors and at least one capacitor.
15. A power converter as recited in claim 14 , further including windings magnetically coupled to said inductor core.
16. A power converter as recited in claim 15 , wherein said windings are formed of cladding on said one or more lower layers and vias in said one or more lower layers.
17. A power converter as recited in claim 16 , wherein said windings are inversely coupled.
18. A power converter as recited in claim 16 , wherein said windings comprise a plurality of turns.
19. A power converter as recited in claim 14 , further including connections formed by vias through said one or more upper layers and said shielding layer.
20. A power converter as recited in claim 14 , wherein said number of layers of said multi-layer architecture is four.