Embedded magnetic component device

• US 9,887,034 B2
• Filed: 10/15/2015
• Issued: 02/06/2018
• Est. Priority Date: 10/17/2014
• Status: Active Grant

• Current Assignee: Murata Manufacturing Co Limited
• Original Assignee: Murata Manufacturing Co Limited
• Inventors: Francis, Lee
• Primary Examiner(s): Hinson, Ronald
• Application Number:
  US14/883,854
• Publication Number:
  US 20160111196A1
• Time in Patent Office: 845 Days
• Field of Search: 336200
• CPC Class Codes: H01F 2027/2809 on stacked layers
• CPC Class Codes: H01F 27/24 Magnetic cores
• CPC Class Codes: H01F 27/2804 Printed windings
• CPC Class Codes: H01F 27/2895 Windings disposed upon ring cores
• CPC Class Codes: H01F 41/046 structurally combined with ferromagnetic material
• CPC Class Codes: H05K 1/0298 Multilayer circuits
• CPC Class Codes: H05K 1/165 incorporating printed inductors
• CPC Class Codes: H05K 2201/086 for inductive purposes, e.g. printed inductor with ferrite core
• CPC Class Codes: H05K 3/4697 having cavities, e.g. for mounting components H05K3/4691 takes precedence

Abstract

A magnetic core is situated in a cavity routed into an insulating substrate. The cavity and magnetic core are coved with a first insulating layer. Through holes are then formed through the first insulating layer and the insulating substrate, and plated to form conductive vias. Metallic traces are added to the exterior surfaces of the first insulating layer and the insulating substrate to form upper and lower winding layers. The metallic traces and conductive vias define the respective primary and secondary side windings for an embedded transformer. At least a second set of the outer conductive vias, are spaced farther from the cavity than a first set, and have greater via hole diameter than the vias in the first set. This reduces the resistance of the windings for a given substrate size and improves the performance of the device.

Claims

1. An embedded magnetic component device, comprising:

an insulating substrate including a first side and a second side opposite the first side, and including a cavity therein, the cavity including an inner and an outer periphery;

a magnetic core included in the cavity; and

an electrical winding that extends through the insulating substrate and around the magnetic core;

wherein

the electrical winding includes;

upper conductive traces located on the first side of the insulating substrate;

lower conductive traces located on the second side of the insulating substrate;

inner conductive connectors extending through the insulating substrate adjacent to the inner periphery of the magnetic core, the inner conductive connectors respectively defining electrical connections between respective upper conductive traces and respective lower conductive traces; and

outer conductive connectors extending through the insulating substrate adjacent to the outer periphery of the magnetic core, the outer conductive connectors respectively define electrical connections between respective first upper conductive traces and respective first lower conductive traces;

wherein

the outer conductive connectors include a first set of outer conductive connectors and a second set of outer conductive connectors;

the first set of outer conductive connectors are located along the outer periphery of the cavity and are spaced from the outer periphery of the cavity by a first distance;

the second set of the outer conductive connectors are located adjacently without the first set of outer conductive connectors in between and at a greater distance from the outer periphery of the cavity than the first set of outer conductive connectors;

each of the first and second set of outer conductive connectors is electrically connected to one of the inner conductive connectors through one of the upper conductive traces or one of the lower conductive traces;

two outer conductive connectors of the second set of outer conductive connectors are located directly adjacent to respective ones of the first set of outer conductive connectors;

in a thickness direction of the insulating substrate, either;

the upper conductive traces connected to the first set of outer conductive connectors do not overlap with the upper conductive traces connected to the second set of outer conductive connectors;

or

the lower conductive traces connected to the first set of outer conductive connectors do not overlap with the lower conductive traces connected to the second set of outer conductive connectors; and

adjacent inner conductive connectors connected to the second set of the outer conductive connectors are located at different distances from the cavity.

2. The device of claim 1, wherein the first side and the second side of the insulating substrate are quadrilateral planar in shape, and the second set of outer conductive connectors are located in a corner of the quadrilateral planar shape.

3. The device of claim 1, wherein:

the upper conductive traces connected to the first set of outer conductive connectors are provided at a same layer as the upper conductive traces connected to the second set of outer conductive connectors;

or

the lower conductive traces connected to the first set of outer conductive connectors are provided at a same layer as the lower conductive traces connected to the second set of outer conductive connectors.

4. The device of claim 1, wherein outer conductive connectors in the second set of outer conductive connectors have a greater cross-sectional area than the outer conductive connectors in the first set of outer conductive connectors.

5. The device of claim 1, wherein electronic components are mounted on the first side and/or the second side of the insulating substrate.

6. The device of claim 1, wherein:

the magnetic core includes a first section and a second section;

the electrical winding includes a primary electrical winding disposed around the first section and a secondary electrical winding disposed around the second section;

the primary electrical winding and the secondary electrical winding are isolated from one another; and

the primary electrical winding and the secondary electrical winding respectively include the upper conductive traces, the lower conductive traces, the inner conductive connectors, and the outer conductive connectors.

7. The device of claim 1, further comprising:

a first isolation barrier located on the first side of the insulating substrate, covering at least the portion of the first side between the primary electrical winding and the second electrical winding where the primary electrical winding and the second electrical winding are closest, and defining a solid bonded joint with the first side of the insulating substrate; and

a second isolation barrier located on the second side of the insulating substrate, covering at least a portion of the second side between the primary electrical winding and the second electrical winding, where the primary electrical winding and the second electrical winding are closest, and defining a solid bonded joint with the second side of the insulating substrate.

8. The device of claim 7, wherein the first isolation barrier and/or the second isolation barrier include a single layer.

9. The device of claim 7, wherein the first isolation barrier and/or the second isolation barrier include a plurality of layers.

10. The device of claim 7, wherein electronic components are mounted on the first isolation barrier and/or the second isolation barrier.

11. The device of claim 1, wherein the magnetic core is an elongated toroid a circular toroid or a gapped circular or elongate toroid, or has an EE, EI, I, EFD, EP, UI or UR toroidal core shape.

12. The device of claim 1, wherein the inner conductive connectors and the outer conductive connectors are conductive wires, pins, or filaments extending through the insulating substrate.