EMBEDDED MAGNETIC COMPONENT DEVICE

• US 20160254089A1
• Filed: 02/26/2016
• Published: 09/01/2016
• Est. Priority Date: 02/26/2015
• Status: Active Grant

• Current Assignee: Murata Manufacturing Co Limited
• Original Assignee: Murata Manufacturing Co Limited
• Inventors: FEATHERSTONE, Christopher, PARISH, Scott Andrew
• Granted Patent: US 10,811,181 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H01F 2027/2819 Planar transformers with printed windings, e.g. surrounded by two cores and to be mounted on printed circuit
• CPC Class Codes: H01F 27/266 Fastening or mounting the core on casing or support on coil H01F27/30
• 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

Abstract

In a method of manufacturing a plurality of embedded magnetic component devices, a row of cavities for respective magnetic cores is formed in an insulating substrate. Neighboring cavities are connected to each other by channels formed in the substrate. Adhesive is applied to a cavity floor throughout the row of cavities, and magnetic cores are inserted into the cavities. The cavities and magnetic cores are covered with a first insulating layer. Through holes are formed through the first insulating layer and the insulating substrate, and plated up 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 form the windings for an embedded magnetic component, such as transformer or inductor.

Claims

1. A method of manufacturing a plurality of embedded magnetic component devices each including a magnetic core embedded in a cavity formed in an insulating substrate and one or more electrical windings formed around the core, the method comprising:

a) preparing a mother base substrate including a row of cavities for respective magnetic cores, each of the cavities including a cavity floor and side walls connected by the cavity floor, and channels formed between the neighboring cavities in the mother base substrate so as to connect the cavities, each of the channels including a channel floor connected to the cavity floor;

b) applying adhesive to the cavity floor and to one or more of the channels throughout the row of cavities;

c) installing magnetic cores into the respective cavities so that the magnetic cores are secured in the cavities by the adhesive;

d) applying an insulating layer to the mother base substrate to cover the magnetic cores and the cavities so as to obtain an insulated mother substrate; and

e) forming electrical windings, passing through the mother substrate and respectively disposed around each of the magnetic cores;

wherein

the magnetic cores are secured in the cavities by the adhesive on the cavity floor.

2. The method of claim 1, further comprising dividing the insulated mother substrate into individual devices each including one of the magnetic cores embedded in the cavity formed in the insulating substrate and one or more of the electrical windings formed around the core.

3. The method of claim 2, wherein the dividing step includes dividing the mother insulated substrate at an intersection of the channels between the neighboring cavities, the individual devices including two or more of the channels connecting the cavity of the device to an exterior of the device.

4. The method of claim 1, wherein applying the layer of adhesive includes applying one or more spots of the adhesive to discrete locations inside the row of cavities, and causing the adhesive to flow between the neighboring cavities via the channels.

5. The method of claim 4, further comprising applying the one or more spots of the adhesive to one or more discrete locations in only the first cavity in the row of cavities.

6. The method of claim 5, wherein the one or more spots of the adhesive are applied only to selected ones of the cavities in the row of cavities, so that some of the cavities do not initially receive the adhesive.

7. The method of claim 5, further comprising inclining the row of cavities to assist with the flow of the adhesive between the cavities after step b).

8. The method of claim 5, further comprising agitating the row of cavities to assist with the flow of the adhesive between the cavities after step b).

9. The method of claim 1, further comprising, before applying the adhesive, forming end channels between the end most cavities in the row and an exterior of the insulating substrate, the end channels including a channel floor and at least one obstruction portion where the channel floor is raised in comparison to the cavity floor which is deeper, the obstruction portion at least partially blocking egress of the adhesive applied during step b).

10. The method of claim 9, further comprising forming the obstruction portion at the end of the end channel remote from the cavity, adjacent the exterior of the substrate.

11. The method of claim 9, further comprising forming the obstruction portion as an entire length of the end channel floor which is raised in comparison to the deeper cavity floor.

12. The method of claim 1, wherein forming the electrical windings includes forming isolated primary and secondary electrical windings, passing through at least the insulating substrate and the insulating layer and disposed around first and second sections of the magnetic core.

13. An embedded magnetic component device comprising:

a base substrate including opposing first and second sides, and a cavity therein, the cavity including a cavity floor, side walls connected by the cavity floor;

a magnetic core housed in the cavity;

an insulating layer located on the base substrate to cover the cavity and the magnetic core and to define an insulated substrate;

one or more electrical windings passing through the insulated substrate and disposed around the magnetic core;

a layer of adhesive located on the cavity floor, securing the magnetic core in the cavity; and

two or more channels located in the insulating substrate and connecting the cavity to two or more portions of an exterior of the insulated substrate, each of the two or more channels including a channel floor connecting to the cavity floor;

wherein

the layer of adhesive extends into the channel floor of at least one of the channels and an edge of the adhesive layer in the at least one channel extends to the exterior of the insulated substrate.

14. The device of claim 13, wherein the insulating substrate includes four side surfaces, and the channels emerge on opposed ones of the four side surfaces.

15. A method of manufacturing a plurality of embedded magnetic component devices each including a magnetic core embedded in a cavity formed in an insulating substrate and one or more electrical windings formed around the core, the method comprising:

a) preparing a mother base substrate including a row of cavities for respective magnetic cores, each of the cavities including a cavity floor and side walls connected by the cavity floor, and channels formed between the neighboring cavities in the mother base substrate so as to connect the cavities, each of the channels including a channel floor connected to the cavity floor;

b) installing magnetic cores into the respective cavities so that the magnetic cores are secured in the cavities by the adhesive;

c) applying an insulating layer to the mother base substrate to cover the magnetic cores and the cavities so as to obtain an insulated mother substrate, the insulating layer including holes for receiving adhesive, the holes communicating with the channels between the magnetic cores;

d) dispensing adhesive into the channels through the holes so that the adhesive contacts the magnetic core and secures the magnetic core to the cavity floor throughout the row of cavities; and

e) after completion of the individual devices, separating the components to form individual devices.

16. The method of claim 15, wherein the mother base substrate includes connection portions and device portions, the connection portions located intermediate of neighboring device portions, the device portions each including a respective cavity for receiving a magnetic core, and the connection portions including at least a portion of the channel connecting neighboring device portions and at least one hole for receiving adhesive, wherein separating the components to form individual devices includes removing the connection portions between the device portions.

17. The method of claim 15, wherein completing the individual devices includes a step of forming the electrical windings, passing through the mother substrate and respectively disposed around each of the magnetic cores, the step of forming the electrical windings occurring before or after the step of dispensing the adhesive.

18. The method of claim 15 further comprising forming the channels with a groove, leading from below the hole to the cavity.

19. The method of claim 15, wherein the channel floor slopes away from the hole towards the cavities.