Hybrid transformer device

• US 4,103,267 A
• Filed: 06/13/1977
• Issued: 07/25/1978
• Est. Priority Date: 06/13/1977
• Status: Expired due to Term

• Current Assignee: Burr-Brown Corporation (Texas Instruments, Inc.)
• Original Assignee: Burr-Brown Research Corporation
• Inventors: Olschewski, Wilfred W.
• Primary Examiner(s): Kozma, Thomas J.
• Application Number:
  US05/806,053
• Time in Patent Office: 407 Days
• Field of Search: 336/200, 336/229, 336/223, 336/65, 336/228, 361/400, 361/403, 29/606, 29/626
• US Class Current: 336/65
• CPC Class Codes: H01F 2027/2814 with only part of the coil or of the winding in the printed circuit board, e.g. the remaining coil or winding sections can be made of wires or sheets
• CPC Class Codes: H01F 27/2804 Printed windings
• CPC Class Codes: H05K 1/165 incorporating printed inductors
• CPC Class Codes: H05K 1/181 associated with surface mounted components
• CPC Class Codes: H05K 2201/086 for inductive purposes, e.g. printed inductor with ferrite core
• CPC Class Codes: H05K 2203/1476 Same or similar kind of process performed in phases, e.g. coarse patterning followed by fine patterning
• CPC Class Codes: H05K 3/222 Completing of printed circuits by adding non-printed jumper connections printed jumper connections H05K3/4685
• CPC Class Codes: Y10T 29/49073 by assembling coil and core
• CPC Class Codes: Y10T 29/49169 Assembling electrical component directly to terminal or elongated conductor

Abstract

A ceramic substrate is provided with a plurality of planar conductors formed on a surface of the substrate; conductors extend substantially radially from an imaginary point on the surface of the substrate. A layer of dielectric material is formed over the major portion of each of the conductors to form a ring of dielectric material to which a ferrite toroidal core is adhesively secured. The core is precoated with an insulating material prior to adhesively being secured to the dielectric ring. A plurality of wire conductors are wire bonded at each end thereof to the exposed ends of the metal conductors on the substrate.

Claims

1. A hybrid transformer device for use in a hybrid integrated circuit, said hybrid transformer device comprising in combination:

(a) a non-conductive substrate having a planar surface;

(b) a plurality of metalized coating conductors formed on said planar surface, each of said conductors having a predetermined length with first and second ends;

(c) a closed loop magnetic core unit adhesively mounted on said substrate over said metal conductors, said closed loop magnetic core unit being an integral unit formed prior to being adhesively mounted on said substrate, said closed loop magnetic core unit having substantially elevated sides to increase the inductance and power handling capability and lower the losses of said hybrid transformer device;

(d) insulating means electrically insulating said closed loop magnetic core unit from said metal conductors; and

(e) a plurality of metal wire bonding conductors of predetermined length each having first and second ends and looping over said closed loop magnetic core unit to form transformer windings, the first end of each of said metal wire bonding conductors being wire bonded to the first end of a different one of said metal conductors, the second end of each of said metal wire bonding conductors being wire bonded to the second end of a different one of said metal conductors.

2. The hybrid transformer device of claim 1 wherein said closed loop magnetic core unit includes a dielectric coating.

3. The hybrid transformer device of claim 2 wherein said dielectric coating forms said insulating means.

4. The combination set forth in claim 1 wherein said closed loop magnetic core unit is a toroidal ferrite core unit.

5. The combination set forth in claim 1 wherein said adhesive material forms a nonrigid bond between said closed loop magnetic core unit and said substrate.

6. The combination set forth in claim 1 wherein said insulating means is formed of a layer of dielectric material formed of a thick film glass between the substrate and said closed loop magnetic core unit.

7. A hybrid transformer device for use in a hybrid integrated circuit, said hybrid transformer device comprising in combination:

(a) a non-conductive substrate having a planar surface;

(b) a plurality of metalized coating conductors formed on said planar surface, each of said conductors having a predetermined length with first and second ends;

(c) a layer of dielectric material on top of and in contact with the major portion of each of said conductors, the ends of each of said conductors extending beyond said dielectric layer;

(d) a toroidal magnetic core unit coated with dielectric material, said toroidal magnetic core unit having substantially elevated sides to increase the inductance and power handling capability of said hybrid transformer device, said toroidal magnetic core unit being an integral unit formed prior to being adhesively bonded to said layer of dielectric material;

(e) a layer of adhesive material adhesively bonding said toroidal magnetic core unit to said layer of dielectric material; and

(f) a plurality of metal wire bonding conductors of predetermined length each having first and second ends and looping over said torroidal magnetic core unit to form transformer windings, the first end of each of said metal wire bonding conductors being wire bonded to the first end of a different one of said metal conductors, the second end of each of said metal wire bonding conductors being wire bonded to the second end of a different one of said metal conductors.

8. The combination set forth in claim 7 wherein said non-conductive substrate is a ceramic material.

9. The combination set forth in claim 7 wherein said layer of adhesive material forms a nonrigid bond between said toroidal magnetic core unit and said layer of dielectric material.

10. The combination set forth in claim 7 wherein said layer of dielectric material is formed of a thick film glass layer.

11. The combination set forth in claim 7 wherein said metal conductors are fire-formed in precious metal on said planar surface.

12. A hybrid transformer device for incorporation into a hybrid integrated circuit, said hybrid transformer device comprising in combination:

(a) a non-conductive substrate having a planar surface;

(b) a plurality of metalized coating conductors formed on said planar surface, each of said conductors having a predetermined length with first and second ends;

(c) a layer of dielectric material on top of and in contact with the major portion of each of said conductors, the ends of each of said conductors extending beyond said dielectric layer;

(d) a toroidal magnetic core unit coated with dielectric material, said toroidal magnetic core unit having substantially elevated sides to increase the inductance and power handling capability of said hybrid transformer device, said toroidal magnetic core unit being an integral unit separately formed prior to use in said hybrid transformer device;

(e) a layer of adhesive material adhesively bonding said toroidal magnetic core unit to said layer of dielectric material; and

(f) a plurality of metal wire bonding conductors of predetermined length each having first and second ends and extending over said toroidal magnetic core unit to form transformer windings, the first end of each of said metal wire bonding conductors being wire bonded to the first end of a different one of said metal conductors, the second end of each of said metal wire bonding conductors being wire bonded to the second end of a metal conductor adjacent said one of said metal conductors.

13. a hybrid transformer device comprising:

(a) a ceramic substrate having a planar surface;

(b) a plurality of metalized coating conductors formed on said planar surface, each of said conductors having a predetermined length with first and second ends and arranged in a pattern whereby each conductor extends substantially radially from an imaginary point on said planar surface;

(c) a ring shaped layer of dielectric material on top of and in contact with said metal conductors with the ends of each of said conductors extending from beneath said dielectric layer;

(d) a toroidal ferrite core unit having substantially elevated sides to increase the inductance and power handling efficiency of said hybrid transformer device;

(e) a layer of nonrigid adhesive material adhesively bonding said toroidal ferrite core unit to said layer of dielectric material with said toroidal ferrite core unit lying flat over said layer of dielectric material; and

(f) a plurality of metal wire bonding conductors of predetermined length each having first and second ends and extending over said toroidal ferrite core unit to form transformer windings, the first end of each of said metal wire bonding conductors being wire bonded to the first end of a different one of said metal conductors, the second end of each of said metal wire bonding conductors being wire bonded to the second end of a metal conductor adjacent said one of said metal conductors.

14. A method of making a hybrid transformer device comprising the steps of:

(a) forming a plurality of metalized coating conductors on a non-conductive substrate, each of the metal conductors having a first end and a second end;

(b) adhesively mounting a closed loop magnetic core unit, having substantially elevated sides to increase the inductance and power handling capability of said hybrid transformer device on the non-conductive substrate by means of a non-rigid adhesive material, such that the first and second ends of said metal conductors remain exposed; and

(c) wire bonding a plurality of metal wire bonding conductors of predetermined length to form transformer windings of said hybrid transformer device by wire bonding one end of each of said metal wire bonding conductors to the first end of a respective one of said metal conductors and looping that wire bonding conductor over a portion of said closed loop magnetic core unit and wire bonding the other end of that metal wire bonding conductor to the second end of an adjacent one of said metal conductors.

15. The method of claim 14 including the step of performing an insulating layer on said substrate, said insulating layer covering a major portion of each of said metal conductors but leaving said first and second ends of each of said metal conductors exposed.

16. The method of claim 14 wherein said wire bonding steps are preprogrammed and are performed utilizing automatic wire bonding techniques.

17. The method of claim 14 wherein said wire bonding is thermal compression wire bonding.

18. The method of claim 14 wherein said wire bonding is ultrasonic wire bonding.