Miniature circuitry and inductive components and methods for manufacturing same

• US 20060152322A1
• Filed: 12/07/2005
• Published: 07/13/2006
• Est. Priority Date: 12/07/2004
• Status: Active Grant

• Current Assignee: M-Flex Multi-Fineline Electronix, Inc., Multi-Fineline Electronix Incorporated (Suzhou Dongshan Precision Manufacturing Company Limited)
• Original Assignee: Multi-Fineline Electronix Incorporated (Suzhou Dongshan Precision Manufacturing Company Limited)
• Inventors: Marcoci, Ciprian, Guerra, Joe D., Whittaker, Ronald W.
• Granted Patent: US 7,271,697 B2
• Time in Patent Office: Days
• US Class Current: 336/200
• CPC Class Codes: H01F 17/0033 with the coil helically wound around a magnetic core
• CPC Class Codes: H01F 17/062 Toroidal core with turns of coil around it
• CPC Class Codes: H01F 19/04 Transformers or mutual inductances suitable for handling frequencies considerably beyond the audio range resonant circuits H03H
• CPC Class Codes: H01F 2017/002 Details of via holes for interconnecting the layers
• 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 41/046 structurally combined with ferromagnetic material
• CPC Class Codes: H05K 1/165 incorporating printed inductors
• CPC Class Codes: H05K 1/189 characterised by the use of a flexible or folded printed circuit H05K3/326 takes precedence
• CPC Class Codes: H05K 2201/0179 Thin film deposited insulating layer, e.g. inorganic layer for printed capacitor
• CPC Class Codes: H05K 2201/086 for inductive purposes, e.g. printed inductor with ferrite core
• CPC Class Codes: H05K 2201/097 Alternating conductors, e.g. alternating different shaped pads, twisted pairs; Alternating components
• CPC Class Codes: H05K 2201/09809 Coaxial layout reduction of cross-talk, noise or interference by printed shielding conductors for shielding around a single via or around a group of vias H05K1/0222
• CPC Class Codes: H05K 2201/10416 Metallic blocks or heatsinks completely inserted in a PCB metallic supports H05K3/0061
• CPC Class Codes: H05K 3/389 by the use of a coupling agent, e.g. silane
• CPC Class Codes: H05K 3/429 Plated through-holes specially for multilayer circuits, e.g. having connections to inner circuit layers
• CPC Class Codes: H05K 3/4644 by building the multilayer layer by layer, i.e. build-up multilayer circuits making via holes in the insulating layers H05K3/0011; special circuit boards as base or core whereon the multilayer is built H05K3/4602
• CPC Class Codes: Y10T 29/49124 On flat or curved insulated base, e.g., printed circuit, etc.
• CPC Class Codes: Y10T 29/49126 Assembling bases
• CPC Class Codes: Y10T 29/49155 Manufacturing circuit on or in base
• CPC Class Codes: Y10T 29/49156 : with selective destruction of conductive paths
• CPC Class Codes: Y10T 29/49165 : by forming conductive walled aperture in base

Abstract

Miniature circuitry and inductor components in which multiple levels of printed circuitry are formed on each side of a support panel, typically a printed circuit board or rigid flex. Electrical connection between the plural levels of circuitry and multiple windings around magnetic members are provided by plural plated through hole conductors. Small through hole openings accommodate a plurality of the plated through hole conductors since each is insulated from the others by a very thin layer of vacuum deposited organic layer such as parylene having a high dielectric strength. Adhesion of this plated copper to the organic layer is provided by first applying an adhesive promotor to the surface of the organic layer followed by the vacuum deposition of the organic layer.

Claims

1. A miniature transformer comprising:

a support member having a toroidal-shaped cavity formed therein,

a ferrite toroid embedded in said cavity such that said toroid is substantially contained within said cavity,

a first and second printed circuit formed on respectively opposite sides of said support member,

a first plurality of plated through holes in said support member around the outside perimeter of said cavity of said toroidal cavity,

a second plurality of plated through holes in said support member around the inside perimeter of said cavity,

said first printed circuit including connecting respective first and second plated through holes,

said second printed circuit including connecting respective first and second plated through holes,

a third plurality of plated through holes in the same holes as said first plurality of plated through holes, said first and third plurality of through holes being electrically insulated from each other by vacuum depositing a thin layer of parylene followed by treating the outside surface of the parylene coated holes with an adhesion promoter.

a fourth plurality of plated through holes in the same holes as said second plurality of plated through holes, said second and fourth plated through holes being electrically insulated from each other by the vacuum deposited thin layer at parylene,

third and fourth printed circuits formed in respective layers over the layers of said first and second printed circuits with an insulated layer therebetween,

said third printed circuit including connecting respective third and fourth plated through holes,

said fourth printed circuit including connecting respective third and fourth through holes,

said plated through holes and printed circuit connections forming primary and secondary windings of said miniature transformer.

2. A miniature transformer comprising:

a support member having a toroid shaped cavity formed therein;

a ferrite toroid embedded in said cavity such that said toroid is substantially contained within said cavity,

first and second printed circuits formed on respectively opposite sides of said support members,

a first plurality of plated through holes in said support member around the outside perimeter of said cavity of toroid cavity,

a second plurality of plated through holes in said support member around the inside perimeter of said cavity,

said first printed circuit including connecting respective first and second plated through holes,

said second printed circuit including connecting respective first and second plated through holes,

a third plurality of plated through holes in the same holes as said first plurality of plated through holes, said first and third plurality of through holes being electrically insulated from each other by a thin vacuum deposited layer of parylene,

a fourth plurality of plated through holes in the same holes as said second plurality of plated through holes, said second and fourth plated through holes being electrically insulated from each other by a thin vacuum deposited layer of parylene,

third and fourth printed circuits formed in respective layers over the layers of said first and second printed circuit with an insulated layer therebetween,

said third printed circuit including connecting respective third and fourth plated through holes,

said fourth printed circuit including connecting respective third and fourth through holes,

said plated through holes and printed circuit connections forming primary and secondary windings of said miniature transfomers.

3. A miniature transformer comprising:

a support member having a toroid shaped cavity found therein,

a ferrite toroid embedded in said cavity such that said toroid is substantially contained within said cavity,

first and second printed circuits formed on respectively opposite sides of said support member,

a first plurality of plated through holes in said support member around the outside perimeter of said cavity of toroidal cavity,

a second plurality of plated through holes in said support member around the inside perimeter of said cavity,

said first printed circuit including connecting respective first and second plated through holes,

said second printed circuit including connecting respective first and second plated through holes,

a third plurality of plated through holes in the same holes as said first plurality of plated through holes, said first and third plurality of through holes being electrically insulated from each other by having a substantially pin-hole free insulating layer having a thickness in the range of about 0.5 mil to 3 mil and having a voltage breakdown guard band in the range of about 5600 to 15,000 volts per mil per unit of thickness,

a fourth plurality of plated through holes in the same holes as said second plurality of plated through holes, said second and fourth plated through holes being electrically insulated from each other by substantially said pin-hole free insulating layer,

third and fourth printed circuit formed in respective layers over the layers of said first and second printed circuits with an insulated layer therebetween,

said third printed circuit including connecting respective third and fourth plated through holes,

said fourth printed circuit including connecting respective third and fourth through holes,

said plated through holes and printed circuit connections forming primary and secondary windings of said miniature transformers.

4. A miniature transformer having a base member,

a cavity formed in said base,

an inductive member located in said cavity, said member providing a magnetic core of said transformer,

a plurality of openings in said base,

a plurality of plated through hole conductors formed in said through hole openings, each of said conductors being respectively electrically insulated from another plated through hole conductor in the same hole by a thin vacuum deposited polymer film,

said plated through hole conductor providing respective electrical primary and secondary transformer windings of said transformer.

5. The transformer of claim 4, wherein said cavity has a substantially toroidal configuration.

6. The transformer of claim 5, wherein said inductive member has a substantially toroidal configuration similar to said cavity.

7. The transformer of claim 4, wherein said cavity has a substantially rectangular configuration.

8. The transformer of claim 7, wherein said conductor member has a substantially rectangular configuration similar to said cavity.

9. The transformer of claim 4, wherein said openings in said base are in said support member proximate to a wall of said inductor member.

10. The transformer of claim 9, having through holes extending through the body of said inductive member.

11. The transformer of claim 4, wherein said base member is formed from a printed circuit board.

12. The transformer of claim 11, wherein said base member is formed of flex circuit.

13. The transformer of claim 4, wherein said cavity is an opening substantially entirely through said base member.

14. The transformer of claim 4, wherein said cavity is formed partially through the wall of said base member to leave a seat of the bottom of the cavity.

15. The transformer of claim 4 wherein said thin vacuum deposited film is parylene.

16. A multiple layered printed circuit comprising

first and second printed circuits on opposite sides of an insulating support member,

insulation layers respectively covering said first and second printed circuits,

third and fourth printed circuits over said insulated first and second layers,

at least one opening through said support member,

at least two plated through conductors in at least one opening, said conductors insulated from each other by a thin vacuum deposited film, and

one of said plated through conductors electrically connected to printed circuits on opposite sides of said support member and another of said plated through hole.

17. The circuit of claim 16, wherein said support member is formed from a printed circuit board.

18. The circuit of claim 16, wherein said support member is formed of flex circuit.

19. The circuit of claim 16, wherein said thin vacuum deposited film is parylene.

20. A circuit composing

a plurality of plated through holes in a support member, and

a thin vacuum deposited insulating member between each of said plated through holes.

21. The circuit of claim 20, wherein said support member is formed from a printed circuit board.

22. The circuit of claim 20, wherein said support member is formed from flex circuit.

23. The circuit of claim 20, wherein said thin vacuum deposited film is parylene.

24. A method for making plural plated through holes in a single circuit board via comprising

plating copper in the walls of said circuit board via to form a first plated through hole,

applying a thin layer of first adhesive promotor to the surface of said plated via,

vacuum deposit an organic layer having a high dielectric strength unto said layer of first adhesive promoter,

applying a second layer of adhesive promoter over said layer of polymer, and

plating copper over said second layer of adhesive promoter to form a second plated through hole in said circuit board via.

25. The method of claim 24 wherein said first adhesive promoter is applied by a PECVD process (Plasma Enhanced Chemical Vapor Deposition).

26. The method of claim 24 wherein said first adhesive promoter is Silane, Carboxyl or Silane and Carboxyl.

27. The method of claim 24 wherein said first adhesive promoter is applied by dipping the through holes in the adhesive promoter.

28. The method of claim 24 wherein said second adhesive promoter is applied by a PECVD process.

29. The method of claim 28 wherein said second adhesive promoter is a Carboxl or Silane gas phase chemical reaction.

30. The method of claim 24 wherein said organic layer is a vacuum deposited.

31. The method of claim 30 wherein said organic layer is a parylene coating.

32. A method for making plural insulated conductor through holes in a single circuit board via comprising:

applying a first conductive layer on the walls of said circuit board via to form a first conductor through hole,

applying a layer of first adhesive promoter to the surface said first conductor layer,

depositing a thin organic layer having a high dielectric strength onto said layer of first adhesive promoter.

applying a second layer of adhesive promoter on said organic layer, and

applying a second conductor layer over said second layer of adhesive promoter.