US 6,664,883 B2Granted

Apparatus and method for PCB winding planar magnetic devices

AssigneeHewlett-Packard Development Company, L.P.

InventorsRaoji A. Patel, James E. Drew, Raymond A. Pelletier, Brian R. McQuain

Life of this patent

Estimating the term…

Loading patent…

Abstract

A method and apparatus to layout planar magnetic coils on a PCB consists of maximizing the layer to layer overlap, and consequently maximizing total inductance for the given layout area, by spiraling alternating layers inward and outward. A further benefit of the matching opposite spirals is the ability to make the layer to layer electrical contacts within the magnetic field area, thus reducing leakage inductance, and minimizing the wasted extra conductor line length needed to make the connections outside the magnetic field. The reduced conductor line length results in reduced conductor line resistance. The method is applicable to voltage transformers and isolation transformers as well as simple inductors and other magnetic devices. In the transformer case the odd numbered layers are typically connected together in series to provide a larger turn ratio, and the even numbered layers are typically single turns (i.e., no spiral) connected together in parallel to provide more current capability.

Claims3

Dependent claims

A method for winding conductors for providing magnetic fields on a PCB having a plurality of conductive layers, comprising the steps of:

winding a first coil having an inward clockwise spiral with a specified number of turns toward a central core on a first conductive layer of the PCB, terminating the inward spiral at an electrical via connection passing through a second conductive layer without making electrical contact, and making electrical contact to a third conductive layer;
winding a second coil having a single turn on the second conductive layer of the PCB, and terminating the winding at an electrical via passing through the third layer without making electrical contact, and making electrical contact to a fourth conductive layer of the PCB;
winding a third coil having an outward clockwise spiral with a specified number of turns away from the central core on an area of the third conductive layer of the PCB which is disposed to be directly underneath the location of the first coil;
and
winding a fourth coil having a single turn on the fourth conductive layer of the PCB on an area of the fourth conductive layer that is disposed to be directly underneath the second coil.

2 more elements

Dependencies are inferred from the claim text.

Facts

Application: 10/167,944Filed 11 Jun 2002 · division
Priority: 1 Feb 2000
Published: US 2002/0057171 A117 Oct 2002
Granted: 16 Dec 2003
Term ends: Not estimatedThe source records don’t support an estimate.

Classification8 codes

H01F 27/2804
Coils; Windings; Conductive connections: printed windings
H01F 38/50
Adaptations of transformers or inductances for specific applications or functions: transformers for galvanic isolation
H01F 41/041
For manufacturing coils: printed circuit coils
H05K 1/165
Incorporating printed electric components, e.g. printed resistors, capacitors or inductors: incorporating printed inductors

Family

Application09/496,150Parent of this division · filed 1 Feb 2000
US 2002/0149461 A1Pre-grant publication · published 17 Oct 2002
US 6,429,763 B1Parent of this division
US 2002/0057171 A1Published application
US 6,664,883 B2This patent

From the US filing history. Foreign family members aren’t listed.