Implantable medical device including a molded planar transformer

Patent metadata

Field	Value
Publication number	US-9607759-B2
Application number	US-201313798698-A
Country	US
Kind code	B2
Filing date	Mar 13, 2013
Priority date	Mar 13, 2013
Publication date	Mar 28, 2017
Grant date	Mar 28, 2017

Abstract

The present disclosure provides methods and techniques associated with a planar transformer for an apparatus. The planar transformers include a substrate carrying electronic components, an upper core bonded on a first exterior surface of the substrate, and a lower core bonded on a second exterior surface opposed to the first side of the substrate. The electronic components include primary windings and secondary windings associated with the transformer. In some embodiments, the transformer includes encapsulant material that is dispensed over and between the components of the transformer to seal air gaps.

First claim

What is claimed is:

1. A method of assembling a transformer, comprising:
providing a substrate having a plurality of substrate units, each of the substrate units including electronic components mounted on a top surface of the substrate units;
providing an adhesive material having first and second opposing surfaces;
mounting a bottom surface of the substrate to the first opposing surface of the adhesive material;
mounting a carrier plate to the second opposing surface of the adhesive material;
placing an upper magnetic core over each of the substrate units, wherein each of the substrate units includes an array of depressions formed on the top surface for receiving the upper magnetic core;
encapsulating the substrate units with an encapsulant material, wherein the encapsulant material is dispensed over an exposed exterior surface of each of the substrate units and within gaps formed between the electronic components and the substrate units;
unmounting the substrate from the adhesive material to remove the carrier plate from the bottom surface of the substrate; and
after unmounting the substrate from the adhesive material, attaching a lower magnetic core to the bottom surface of each of the substrate units.

2. The method of claim 1 , further comprising embedding a set of primary windings and a set of secondary windings into each of the substrate units.

3. The method of claim 1 , wherein the array of depressions is configured with three vertical legs that define an inverted “E” shaped gap surface and the upper magnetic core is shaped to correspond to the array of depressions.

4. The method of claim 1 , wherein a fixation mechanism for attaching the lower magnetic core includes a pressure sensitive adhesive.

5. The method of claim 1 , wherein the dispensing of the encapsulant material comprises filling the gaps formed between the electronic components and the substrate to remove air gaps.

6. The method of claim 1 , wherein the encapsulant material comprises an insulating material.

7. The method of claim 1 , further comprising coupling terminal connectors to the bottom surface of the substrate units prior to encapsulating the substrate.

8. The method of claim 7 , wherein the terminal connectors comprise copper spheres coupled to the electronic components.

9. The method of claim 1 , further comprising grinding the encapsulant material to expose the upper and lower magnetic cores and the terminal connectors.

10. The method of claim 1 , wherein the adhesive material is a release tape selected from one of a thermal release tape and a solvent releasable tape.

11. The method of claim 1 , wherein the electronic components included in each of the substrate units comprises a set of primary and secondary windings.

12. The method of claim 1 , wherein the lower magnetic core is shaped as a horizontal strip that defines an inverted “I” shape.

13. The method of claim 1 , further comprising singulating the substrate units from the substrate to separate individual ones of the transformers.

14. The method of claim 1 , further comprising grinding the encapsulant material to expose the upper magnetic core.

15. The method of claim 14 , wherein the grinding is controlled to yield a package having predetermined dimensions.

16. The method of claim 1 , further comprising coupling a surface mount component to the substrate prior to encapsulating the substrate with an encapsulant material.

17. The method of claim 16 , further comprising coupling an electrical connector to the bottom surface of the substrate units prior to encapsulating the substrate, wherein the electrical connector is coupled to the surface mount component.

Assignees

• Medtronic Inc

Inventors

• Boone Mark R
• Askarinya Mohsen
• Ricotta Mark S
• Wang Lejun

Classifications

• H01F41/005 Primary

  Impregnating or encapsulating (insulating of windings H01F41/12) · CPC title

• Y10T29/49075

  including permanent magnet or core · CPC title

• H01F27/266

  Fastening or mounting the core on casing or support (on coil H01F27/30) · CPC title

• B23P17/04

  characterised by the nature of the material involved or the kind of product independently of its shape · CPC title

• H01F2027/2819

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