Via for magnetic core of inductive component

Patent metadata

Field	Value
Publication number	US-11404197-B2
Application number	US-201816003621-A
Country	US
Kind code	B2
Filing date	Jun 8, 2018
Priority date	Jun 9, 2017
Publication date	Aug 2, 2022
Grant date	Aug 2, 2022

Abstract

Techniques for fabricating low-loss magnetic vias within a magnetic core are provided. According to some embodiments, vias with small, well-defined sizes may be fabricated without reliance on precise alignment of layers. According to some embodiments, a magnetic core including a low-loss magnetic via can be wrapped around conductive coils of an inductor. The low-loss magnetic vias can improve performance of an inductive component by improving the quality factor relative to higher loss magnetic vias.

First claim

What is claimed is:

1. A transformer for transferring power and providing galvanic isolation, the transformer comprising:
a primary coil and a secondary coil;
a magnetic core comprising a lower layer of the magnetic core, an upper layer of the magnetic core, and a via coupling the lower layer of the magnetic core to the upper layer of the magnetic core;
a first insulation layer formed over the lower layer of the magnetic core; and
a separation layer formed over the lower layer of the magnetic core and arranged alongside the first insulation layer,
wherein at least a portion of the primary coil, at least a portion of the secondary coil, the separation layer, and the first insulation layer are disposed between the lower layer and the upper layer of the magnetic core;
wherein the at least a portion of the primary coil contacts the first insulation layer without contacting the separation layer;
wherein the via passes through the separation layer to provide a pathway for magnetic flux between the lower layer and the upper layer of the magnetic core;
wherein the separation layer is arranged between the lower layer and the upper layer of the magnetic core on opposing sides of the via; and
wherein the separation layer and the first insulation layer are formed from different materials.

2. The transformer of claim 1 , wherein the via has a width that is narrower than a width of a portion of the lower layer of the magnetic core that extends substantially parallel to the upper layer of the magnetic core.

3. The transformer of claim 1 , wherein the lower layer of the magnetic core is coupled to a semiconductor substrate, and wherein a distance from the separation layer to the semiconductor substrate is smaller than a distance from either the primary or secondary coil to the semiconductor substrate.

4. The transformer of claim 1 , further comprising a lamination layer at an interface coupling the lower layer to the via.

5. The transformer of claim 4 , wherein a thickness of the lamination layer is 10 nm or smaller.

6. The transformer of claim 1 , wherein the via passes through the separation layer at a sloped angle.

7. The transformer of claim 1 , further comprising a plurality of vias arranged in at least two rows.

8. The transformer of claim 1 , further comprising additional vias arranged in a row with the via.

9. The transformer of claim 1 , wherein at least one of the primary coil or the secondary coil has a non-uniform turns density configured to compensate for magnetic core saturation non-uniformity of the magnetic core.

10. The transformer of claim 1 , wherein the first insulating layer contacts the separation layer.

11. The transformer of claim 1 , wherein the first insulating layer and the separation layer both contact the lower layer of the magnetic core.

12. The transformer of claim 1 , wherein the separation layer is thinner than a combination of thicknesses of the portion of the primary coil, the portion of the secondary coil, and the first insulating layer.

13. A transformer for transferring power and providing galvanic isolation, the transformer comprising:
an upper layer of a magnetic core;
a lower layer of the magnetic core;
a first conductor coil at least part of which is arranged between the upper layer and the lower layer of the magnetic core;
a second conductor coil at least part of which is arranged between the upper layer and the lower layer;
a via comprising magnetic material, the via providing a pathway for magnetic flux between the upper layer and the lower layer;
a separation layer formed from a first material, at least a portion of the separation layer being arranged on and in contact with the lower layer of the magnetic core and between the upper layer and the lower layer of the magnetic core, wherein the via is formed by a pathway through the separation layer; and
an insulating layer formed from a second material, different from the first material, at least a portion of the insulating layer being arranged on and in contact with the lower layer of the magnetic core and between the upper layer and the lower layer of the magnetic core,
wherein the first conductor coil contacts the insulating layer and does not contact the separation layer.

14. The transformer of claim 13 , wherein the via has substantially the same width along the entirety of the via.

15. The transformer of claim 13 , wherein at least one of the first conductor coil or the second conductor coil has a non-uniform turns density configured to compensate for magnetic core saturation non-uniformity of the magnetic core.

16. The transformer of claim 13 , further comprising a lamination layer at an interface coupling the upper layer to the via.

17. The transformer of claim 13 , wherein the insulating layer contacts the separation layer.

18. A transformer for transferring power and providing galvanic isolation, the transformer comprising:
an upper layer of a magnetic core;
a lower layer of the magnetic core;
a coil, at least part of which is arranged between the upper layer and the lower layer of the magnetic core;
a separation layer formed from a first material, at least a portion of the separation layer being arranged on and in contact with the lower layer of the magnetic core and between the upper layer and the lower layer of the magnetic core, wherein a via providing a pathway for magnetic flux between the upper layer and the lower layer of the magnetic core is formed by an opening in the separation layer; and
an insulating layer formed from a second material, different from the first material, at least a portion of the insulating layer being arranged on and in contact with the lower layer of the magnetic core and between the upper layer and the lower layer of the magnetic core,
wherein the insulating layer is thicker than the separation layer.

19. The transformer of claim 18 , wherein the separation layer comprises a first portion that contacts the insulating layer and a second portion that does not contact the insulating layer, and wherein the first and second portion of the separation layer are arranged on opposing sides of the via.

20. The transformer of claim 18 , wherein a width of the via is less than a thickness of the upper layer of the magnetic core.

Assignees

• Analog Devices Global Unlimited Co

Inventors

• Kubik Jan
• Stenson Bernard Patrick
• Morrissey Michael

Classifications

• H01F2027/348

  Preventing eddy currents · CPC title

• H01F2027/2819

  Planar transformers with printed windings, e.g. surrounded by two cores and to be mounted on printed circuit · CPC title

• H01F27/2804

  Printed windings · CPC title

• H01F2027/2809

  on stacked layers · CPC title

• H01F27/255

  made from particles (H01F27/26 takes precedence) · CPC title