Multilayer transformer structure comprising multiple rectification elements

Patent metadata

Field	Value
Publication number	US-11004591-B2
Application number	US-201916387301-A
Country	US
Kind code	B2
Filing date	Apr 17, 2019
Priority date	Apr 17, 2019
Publication date	May 11, 2021
Grant date	May 11, 2021

Abstract

A power conversion circuit has a multilayer transformer and a plurality of rectifying transistors coupled to the secondary windings of the multilayer transformer. The multilayer transformer is formed as multiple layers within a PCB stack, where primary winding conductors and secondary winding conductors are vertically aligned and stacked. The secondary winding conductors are constructed to have one or more secondary winding arms that provide area to which the plurality of rectifying transistors are physically connected. The primary winding conductors are constructed to have a primary winding arm. A footprint of each primary winding conductor is configured to substantially overlap an entire footprint of each of the secondary winding conductors. As such, an entirety of the secondary current flowing through the secondary winding conductors is vertically aligned with the primary winding conductors, and therefore with the primary current flowing through the secondary winding conductors.

First claim

What is claimed is:

1. A power conversion circuit comprising:
a. a printed circuit board stack comprising a plurality of layers stacked together;
b. a multilayer transformer formed within the printed circuit board stack, wherein the multilayer transformer comprises a plurality of primary winding conductors and a plurality of secondary winding conductors, each primary winding conductor formed as a corresponding one layer of the printed circuit board stack and each secondary winding conductor formed as a corresponding one layer of the printed circuit board stack, further wherein a footprint of each primary winding conductor is configured to substantially vertically overlap an entire footprint of each of the secondary winding conductors; and
c. a plurality of rectifying transistors, each rectifying transistor is connected to one of the plurality of secondary winding conductors.

2. The power conversion circuit of claim 1 wherein the plurality of rectifying transistors are physically located relative to the plurality of primary winding conductors to be vertically aligned with the AC current path through the multilayer transformer.

3. The power conversion circuit of claim 2 wherein the AC current path comprises a primary current path through each of the primary winding conductors.

4. The power conversion circuit of claim 1 wherein a structure of the multilayer transformer enables the injection and removal of DC current into and out of a transformer block defined as a vertical space formed by the vertically aligned and stacked plurality of primary winding conductors and plurality of secondary winding conductors.

5. The power conversion circuit of claim 1 wherein the plurality of rectifying transistors are each vertically aligned with the footprint of each primary winding conductor.

6. The power conversion circuit of claim 1 wherein each secondary winding conductor comprises a plurality of secondary winding conductor arms.

7. The power conversion circuit of claim 6 wherein each secondary winding conductor comprises a first secondary winding conductor arm and a second secondary winding conductor arm separated by a discontinuous break in the secondary winding conductor.

8. The power conversion circuit of claim 7 wherein each layer in the printed circuit board stack that includes the secondary winding conductor connected to the rectifying transistor further includes a DC node conductor, further wherein the DC node conductor includes a DC node protrusion that extends into the discontinuous break between the first secondary winding conductor arm and the second secondary winding conductor arm.

9. The power conversion circuit of claim 8 wherein the DC node protrusion is vertically aligned with each of the primary winding conductors.

10. The power conversion circuit of claim 8 wherein one or more connection points on each rectifying transistor is connected to one of the secondary winding conductors, and one or more other connection points on each rectifying transistor is connected to the DC node conductor on the same layer as the connected secondary winding conductor.

11. The power conversion circuit of claim 10 wherein the one or more other connection points on each rectifying transistor connected to the DC node conductor on the same layer as the connected secondary winding conductor are connected to the DC node protrusion.

12. The power conversion circuit of claim 8 wherein each rectifying transistor physically straddles a discontinuous break between the DC node protrusion and one of the first secondary winding conductor arm and the second secondary winding conductor arm.

13. A power conversion circuit comprising:
a. a printed circuit board stack comprising a plurality of layers stacked together;
b. a multilayer transformer formed within the printed circuit board stack, wherein the multilayer transformer comprises a plurality of primary winding conductors and a plurality of secondary winding conductors vertically aligned with the plurality of primary winding conductors; and
c. a plurality of rectifying transistors, each rectifying transistor is connected to one of the plurality of secondary winding conductors,
wherein a structure of the multilayer transformer enables the injection and removal of DC current into and out of a transformer block defined as a vertical space formed by the vertically aligned and stacked plurality of primary winding conductors and plurality of secondary winding conductors.

Assignees

• Flex Ltd

Inventors

• Appelberg Mikael
• Persson Oscar
• Karlsson Magnus
• Wang Qiuhong

Classifications

• H05K2201/10166

  Transistor · CPC title

• H05K2201/09609

  Via grid, i.e. two-dimensional array of vias or holes in a single plane · CPC title

• H01F27/40

  Structural association with built-in electric component, e.g. fuse · CPC title

• H05K1/115

  Via connections; Lands around holes or via connections (H05K1/112 takes precedence) · CPC title

• H05K2201/1003

  Non-printed inductor · CPC title