Structures and methods for controlling losses in printed circuit boards

• US 9,800,109 B2
• Filed: 09/30/2016
• Issued: 10/24/2017
• Est. Priority Date: 10/02/2015
• Status: Active Grant

• Current Assignee: E-Circuit Motors
• Original Assignee: E-Circuit Motors
• Inventors: Shaw, Steven Robert
• Primary Examiner(s): DESAI, NAISHADH N
• Application Number:
  US15/283,088
• Publication Number:
  US 20170098973A1
• Time in Patent Office: 389 Days
• Field of Search: 310179-210
• CPC Class Codes: H02K 2213/03 Machines characterised by numerical values, ranges, mathematical expressions or similar information
• CPC Class Codes: H02K 3/26 consisting of printed conductors
• CPC Class Codes: H02K 5/225 Terminal boxes or connection arrangements specially adapted for submersible motors H02K5/132
• CPC Class Codes: H02K 9/223 Heat bridges
• CPC Class Codes: H05K 1/0298 Multilayer circuits
• CPC Class Codes: H05K 1/115 Via connections; Lands around holes or via connections H05K1/112 takes precedence
• CPC Class Codes: H05K 1/165 incorporating printed inductors
• CPC Class Codes: H05K 2201/09272 Layout details of angles or corners
• CPC Class Codes: H05K 2201/1009 Electromotor

Abstract

The disclosure relates to printed circuit board motors and specifically to printed circuit boards used in motors and generators. Windings formed from copper on printed circuit boards have been used for purposes of forming antennas, inductors, transformers, and stators that can be incorporated in permanent magnet brushless DC (permanent magnet synchronous) machines. For energy conversion devices using modern permanent magnet materials and PCB stators, the magnetic field is not strongly confined by magnetically susceptible materials. Thus, the interaction between fields from adjacent turns in a winding, and/or windings on adjacent layers (for a multilayer configuration) may be significant. The structures disclosed hereinafter reduce the effective resistance in the windings, and therefore reduce the associated losses to achieve a reduced current density in portions of the rotating energy conversion devices. The effect of the disclosed structures is a measurable reduction in loss mechanisms as a function increasing frequency, compared to the currently available devices. These effects are significant in frequency ranges important to energy conversion processes as well as typical control strategies, for example, pulse-width modulation.

Claims

1. A stator, comprising:

a planar composite structure (PCS) comprising at least one dielectric layer and a conductive pattern on a surface of each said dielectric layer, said conductive pattern comprising;

a plurality of first conductive traces, each extending radially from an inner radius to an outer radius and disposed angularly on one of the dielectric surfaces;

at least one of the first conductive traces connected at its outer radius to at least one other of the first conductive traces at its outer radius by a first interconnect;

wherein at least said first interconnect is bounded by an inner edge and an outer edge, and has a starting region, a transition region, an ending region, and the starting region having a first radiused inner edge section extending from the first conductive trace to the transition region, and the ending region having a second radiused inner edge section extending from the transition region to the other conductive trace; and

wherein at least the first radiused inner edge section and the second radiused inner edge section are each characterized at least in part by the Corner Equation

r(θ

)=r_d+(r_s−

r_d)e<sup>−

(θ

-θ

s)/α</sup>

for a corner starting at θ

_s and r_s and evaluated for θ

>

θ

_s, or the equivalent reflected version with

r(θ

)=r_d+(r_s−

r_d)e<sup>−

(θ

s-θ

)/α</sup>

for a corner evaluated with θ

<

θ

_s and ending at θ

_s and r_s, and

where α

is a parameter adjusted according to the required physical structure of the stator.

2. The stator of claim 1 wherein the Corner Equation for the entire inner edge region of the interconnect is characterized by the single equation

3. The stator of claim 1, wherein the stator is a multi-layer stator, and further including

a connecting structure for interconnecting the starting region of one conductive trace to the ending region of a second conductive trace on a different layer.

4. The stator of claim 1 wherein the angular separation between two adjacent first conductive traces is δ

radians, and

α

ranges between 0.06δ and

0.2δ

radians.

5. A stator, comprising:

a planar composite structure (PCS) comprising at least one dielectric layer and a conductive pattern on a surface of each said dielectric layer, at least one conductive pattern comprising;

a plurality of first conductive traces, each extending radially from an inner radius to an outer radius and disposed angularly on one of the dielectric surfaces;

at least one of the first conductive traces connected at its outer radius to at least one other of the first conductive elements at its outer radius by a first interconnect;

wherein at least said first interconnect is bounded by an inner edge and an outer edge, and has a starting region, a transition region, an ending region, and the starting region has a first radiused inner edge section and a first radiused outer edge section extending from the first conductive trace to the transition region, and a second radiused inner edge section and a second radiused outer edge section extending from the transition region and the other conductive trace; and

wherein at least the first radiused inner and outer edge sections and the second radiused inner and outer edge sections are each characterized at least in part by a Corner Equation

r(θ

)=r_d+(r_s−

r_d)e<sup>−

(θ

-θ

s)/α</sup>

for a corner starting at θ

_s and r_s and evaluated for θ

>

θ

_s, or the equivalent reflected version with

r(θ

)=r_d+(r_s−

r_d)e<sup>−

(θ

s-θ

)/α</sup>

for a corner evaluated with θ

<

θ

_s and ending at θ

_s and r_s, and where α

is a parameter adjusted according to the required physical structure of the stator.

6. A stator, comprising:

a planar composite structure (PCS) comprising at least one dielectric layer and a conductive pattern on a surface of each said dielectric layer, at least one conductive pattern comprising;

a plurality of first conductive traces, each extending radially from an inner radius to an outer radius and disposed angularly on one of the dielectric surfaces;

at least one of the first conductive traces connected at its outer radius to at least one other of the first conductive elements at its outer radius by a first interconnect;

wherein at least said first interconnect is bounded by an inner edge and an outer edge, and has a starting region, a transition region, an ending region, and the starting region has a first radiused inner edge section extending from the first conductive trace at its outer radius to the transition region, and a second radiused inner edge section extending from the transition region to the other conductive trace at its outer radius; and

wherein at least the first radiused inner edge section and the second radiused inner edge section are each characterized by a slope dr/dθ

which is a linear function of r(θ

) from the one conductive trace to the transitional region and where the slope dr/dθ

is a different linear function from the transitional region to the other conductive trace.

7. A stator, comprising:

a planar composite structure (PCS) comprising at least one dielectric layer and a conductive pattern on a surface of each said dielectric layer, at least one conductive pattern comprising;

a plurality of first conductive traces, each extending radially from an inner radius to an outer radius and disposed angularly on one of the dielectric surfaces;

at least one of the first conductive traces connected at its outer radius to a starting region of a first interconnect at its outer radius, said first interconnect being bounded by an inner edge and an outer edge and having said starting region, a transition region, and an ending region, and a first radiused inner edge section extending from the outer radius of the one conductive trace to the transition region, and a second radiused inner edge section extending from the transition region to the other conductive trace at its outer radius; and

at any point between the inner and outer edge, the smallest current density magnitude under direct current excitation is not less than 50% of the largest current density magnitude evaluated along the shortest line between the inner and outer edge passing through that point.

8. A stator, comprising:

a planar composite structure (PCS) comprising at least two dielectric layers and a conductive pattern on a surface of each said dielectric layer, at least one conductive pattern comprising;

a plurality of first conductive traces, each extending radially from an inner radius to an outer radius and disposed angularly on different ones of the dielectric surfaces;

at least one of the first conductive traces connected at its outer radius to at least one other of the first conductive traces on a different surface at its outer radius by a first interlayer interconnect;

wherein at least said first interlayer interconnect has a starting region on a first layer, a transition region, and an ending region on a different layer, and further comprising a first radiused inner edge section extending from a first conductive trace to the transition region, and a second radiused inner edge section extending from the transition region to said other conductive trace at its outer radius; and

wherein at least the first radiused inner edge section and the second radiused inner edge section are each characterized at least in part by a structure designed to reduce parasitic and eddy current effects on axially adjacent conductive surface structures.

9. A stator, comprising:

a planar composite structure (PCS) comprising at least one dielectric layer and a conductive pattern on a surface of each said dielectric layer, at least one conductive pattern comprising;

a plurality of first conductive traces, each extending radially from an inner radius to an outer radius and disposed angularly on one of the dielectric surfaces;

at least one of the first conductive traces connected at its outer radius to at least one other of the first conductive elements at its outer radius by a first interconnect;

wherein at least said first interconnect is bounded by an inner edge and an outer edge and has a starting region, a transition region, an ending region, and a first radiused inner edge section extending from the connected first conductive trace at it outer radius to the transition region, and a second radiused inner edge section connecting the transition region to the outer radius of the one other conductive trace; and

wherein at least the first radiused inner edge section and the second radiused inner edge section are each characterized by a structure for reducing eddy currents in the outer conductive portions of the interconnect.

10. A stator, comprising:

a planar composite structure (PCS) comprising at least one dielectric layer and a conductive pattern on a surface of each said dielectric layer, at least one conductive pattern comprising;

a plurality of first conductive traces, each extending radially from an inner radius to an outer radius and disposed angularly on one of the dielectric surfaces;

at least one of the first conductive traces connected at its outer radius to at least one other of the first conductive traces at its outer radius by a first interconnect;

wherein at least said first interconnect is bounded by an inner edge and an outer edge, and has a starting region, a transition region, an ending region, and first radiused inner and outer edge sections extending from the first conductive trace to the transition region, and second radiused inner and outer edge sections extending from the transition region to the one other conductive trace at its outer radius; and

wherein at least the respective slope of the first radiused inner edge section and outer edge section and the second radiused inner edge section and outer edge section are each characterized by a monotonically changing value of slope as a function of the rotational angle from the one conductive trace to the other conductive trace.

11. A stator, comprising:

a planar composite structure (PCS) comprising at least one dielectric layer and a conductive pattern on a surface of each said dielectric layer, at least one conductive pattern comprising;

a plurality of first conductive traces, each extending radially from an inner radius to an outer radius and disposed angularly on one of the dielectric surfaces;

at least one of the first conductive traces connected at its outer radius to at least one other of the first conductive traces at its outer radius by a first interconnect;

wherein at least said first interconnect is bounded by an inner edge and an outer edge, and has a starting region, a transition region, an ending region, and a first radiused inner edge section and a first radiused outer edge section extending from the first conductive trace to the transition region, and a second radiused inner edge section and a second radiused outer edge section extending from the transition region to the one other conductive trace at the outer radius of the other conductive trace; and

wherein at least between the inner edge and the outer edge of the interconnect in its transition region, the interconnect has at least one slit-like elongated region that does not substantially reduce electrical conductivity from one end of the interconnect to the other end of the interconnect, and extending substantially parallel to the inner edge in the transition region of the interconnect.

12. A stator, comprising:

a planar composite structure (PCS) comprising at least one dielectric layer and a conductive pattern on a surface of each said dielectric layer, at least one conductive pattern comprising;

a plurality of first conductive traces, each extending radially from an inner radius to an outer radius and disposed angularly on one of the dielectric surfaces;

at least one of the first conductive traces connected at its outer radius to at least one other of the first conductive traces at its outer radius by a first interconnect;

wherein at least said first interconnect is bounded by an inner edge and an outer edge, and has a starting region, a transition region, and an ending region, and a first radiused inner edge section extending from the first conductive trace to the transition region, and a second radiused inner edge section extending from the transition region to the one other conductive trace at the outer radius of the other conductive trace; and

wherein the inner edge of the interconnect from the connection between the first conductive trace and the starting region to the beginning of the transition region is designated the “

CT inner edge”

distance, and achieves at least 90% of the maximum current density value, as determined by FEA/FEM calculations, within the first 20% of the CT inner edge measured along the inner edge of the interconnect from the first conductive trace toward the transition region.

13. A printed circuit board, comprising:

a planar composite structure (PCS) comprising at least one dielectric layer and a conductive pattern on a surface of each said dielectric layer, said conductive pattern comprising;

a plurality of first conductive traces;

at least one of the first conductive traces connected at a first end to at least one other conductive trace by a first interconnect the connected ends of the conductive traces being angularly offset from each other;

wherein at least said first interconnect is bounded by an inner edge and an outer edge, and has a starting region, a transition region, an ending region, and the starting region has a first radiused inner edge section extending from the first conductive trace to the transition region, and the ending region having a second radiused inner edge section extending from the transition region to the other conductive trace; and

wherein at least the first radiused inner edge section and the second radiused inner edge section are each characterized at least in part by the Corner Equation

r(θ

)=r_d+(r_s−

r_d)e<sup>−

(θ

-θ

s)/α</sup>

for a corner starting at θ

_s and r_s and evaluated for θ

>

θ

_s, or the equivalent reflected version with

r(θ

)=r_d+(r_s−

r_d)e<sup>−

(θ

s-θ

)/α</sup>

for a corner evaluated with θ

<

θ

_s and ending at θ

_s and r_s, and

where α

is a parameter adjusted according to the required physical structure of the connected traces.

14. The printed circuit board of claim 13 wherein the board has a multilayered structure and the interconnect connects one trace on a first board layer and a second trace on a second board layer.