Information
-
Patent Grant
-
6587025
-
Patent Number
6,587,025
-
Date Filed
Wednesday, January 31, 200123 years ago
-
Date Issued
Tuesday, July 1, 200320 years ago
-
Inventors
-
Original Assignees
-
Examiners
Agents
- McKee, Voorhees & Sease, P.L.C
-
CPC
-
US Classifications
Field of Search
US
- 336 65
- 336 83
- 336 180
- 336 200
- 336 232
- 336 233
- 336 234
- 029 6021
-
International Classifications
-
Abstract
A side-by-side coil inductor includes a first coil comprising a plurality of conductive first coil segments positioned one above another and connected in series. A second coil includes a plurality of conductive second coil segments positioned above one another and connected together in series. The first and second coil are in side-by-side position relative to one another and are connected together in series. Each of the first and second coil are approximately circular or square in configuration and the total configuration of the two coils is rectangular.
Description
BACKGROUND OF THE INVENTION
This invention relates to a side-by-side coil inductor.
Many electrical components, and electrical inductors in particular, have length and width dimensions which differ by a factor of 1.5 to 2.5 to facilitate component orientation. This is done to avoid mispositioning a square part by automated robotic assembly equipment which utilizes the size for proper orientation. In this process square components can be rotated 90° from the proper orientation. Proper orientation is important for yielding the proper electrical characteristics, and improper orientation can result in electrical defects.
Inductors are elongated conductors which can take many shapes: straight, wound in a shape such as an oval, square, round, or many other configurations. The maximum inductance from a length of wire requires it to be in the shape of a circle.
Many prior art inductors utilize an oval shaped coil pattern.
FIGS. 1 and 2
illustrate these typical prior art inductors.
Referring to
FIG. 1
the numeral
10
generally designates a typical prior art monolithic chip inductor. Inductor
10
comprises a plurality of sub assemblies stacked upon one another. A bottom sub assembly
20
includes a ferrite bottom layer
22
and a bottom coil inductor
24
printed over ferrite layer
22
. Coil conductor
24
has an outer end
26
and an inner end
28
. The bottom ferrite layer
22
includes a front edge
14
, a rear edge
16
and opposite side edges
18
.
Printed over the bottom subassembly
20
is a first intermediate subassembly
30
. Subassembly
30
includes a first intermediate ferrite layer
32
having a via hole
34
extending therethrough. Via hole
34
is registered immediately above the inner coil end
28
of bottom conductor coil
24
.
Printed over the upper surface of first intermediate ferrite layer
32
is a first intermediate coil conductor
36
having an outer end
40
. Via hole
34
is filled with a conductive filler
42
which provides electrical connection between an inner end
38
of the first intermediate coil
36
and an inner end
28
of bottom coil
24
.
Printed above the first intermediate subassembly
30
is a second intermediate subassembly
44
having a second ferrite layer
46
formed with a via hole
48
and having a second intermediate coil conductor
50
printed on the second intermediate ferrite layer
46
. Second intermediate coil conductor
50
has an outer end
52
registered above via hole
48
. Via hole
48
is filled with a conductive filler
56
registered above the outer coil end
40
of first intermediate coil
36
. Conductive filler provides electrical connection between the outer coil end
40
of the first intermediate coil
36
and the outer coil end
52
of second intermediate coil
50
. Second intermediate coil
50
also includes an inner end
54
.
Printed above a second intermediate subassembly
44
is a top subassembly
58
which comprises a top ferrite layer
60
having a via hole
62
extending therethrough and a top coil conductor
64
printed over the upper surface thereof. Top coil conductor
64
includes a first end
66
and a second end
68
. End
68
functions as a terminal and extends to the end edge of top ferrite layer
60
. First terminal
66
is positioned above the via hole
62
. Conductive filler
69
is within via hole
62
and provides electrical connection between the top terminal
66
and the inner coil end
54
of the second intermediate coil conductor
50
.
A ferrite top cap layer
70
is printed over the top subassembly
58
and covers the top subassembly
58
.
FIG. 2
illustrates schematically the typical prior art coil structure provided by the exploded view shown in FIG.
1
. The coil commences at its lower end
26
and proceeds in a helical pattern upwardly until it reaches the upper end
68
. The general configuration of the coil assembly
10
is rectangular or ovular. That is its length is substantially greater than its width. This enables a robotic assembly of the component into a circuit, and the robotic equipment can sense the rectangular shape of the assembly so as to permit it to be properly oriented within the circuitry.
However, the rectangular or ovular shape of the coils within the coil assembly detracts from the maximum inductance which can be obtained. Inductance is maximum with a circle or a square configuration.
The primary object of the present invention is the provision of an improved coil conductor.
A further object of the present invention is the provision of an improved coil inductor that utilizes the same rectangular space of prior coil inductors, but provides two circular or square coils within that space.
A further object of the present invention is the provision of an improved coil conductor which utilizes two circular or square coils in side-by-side relationship to maximize the inductance for parts of the same size.
A further object of the present invention is the provision of an improved side-by-side coil conductor which is economical to manufacture, durable in use, and efficient in operation.
SUMMARY OF THE INVENTION
A side-by-side coil inductor includes a first coil comprising a plurality of conductive first coil segments positioned one above another. The first coil segments are connected together in series. A second coil includes a plurality of conductive second coil segments positioned one above another. The second coil segments are also connected together in series. The first and second coils are in side-by-side position relative to one another and are connected together in series.
According to one feature of the invention a plurality of ferrite layers alternate between adjacent pairs of the first coil layers and between adjacent pairs of the second coil layers to create an inductor body having an elongated shape with a body length greater than the body width.
According to another feature of the invention the first and second coils have approximately the same width and length to maximize their inductance. Preferably they are square or circular in configuration, but they may have other similar configurations without detracting from the invention.
BRIEF DESCRIPTION OF THE FIGURES OF THE DRAWINGS
FIG. 1
is an exploded perspective view of a prior art inductor coil.
FIG. 2
is a schematic view of the prior art inductor coil of FIG.
1
.
FIG. 3
is an exploded perspective view of the side-by-side coil inductor of the present invention.
FIG. 4
is a schematic view of the side-by-side coil inductor of the present invention.
FIG. 5
is a perspective view of an inductor body showing the coil inductor within.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to
FIGS. 3 and 4
a side-by-side coil inductor
72
includes a bottom ferrite layer
74
. First and second conductive bottom coil segments
76
,
78
are fitted on the upper surface of the bottom ferrite layer
74
. A coil connecting section
80
connects the two bottom segments
76
,
78
in series with one another. Each of the bottom coil segments
76
,
78
include an inner end
82
,
84
respectively.
A second ferrite layer
86
is superimposed over the first ferrite layer
74
and includes first and second coil segments
88
,
90
which are in registered alignment above the bottom coil segments
76
,
78
.
Each of the first and second coil segments
88
,
90
includes an inner end
92
,
94
respectively and an outer end
96
,
98
respectively. Second ferrite layer
86
is provided with a first via hole
100
and a second via hole
102
registered below the inner ends
92
,
94
respectively of the coil segments
88
,
90
. Within the via holes
100
and
102
are a first via fill
104
and a second via fill
106
respectively. Via fill
104
provides electrical connection between the inner end
92
of coil segment
88
and the inner end
82
of coil segment
76
. Similarly the via fill
106
provides electrical connection between the inner end
94
of coil segment
90
and the inner end
84
of the coil segment
78
.
A third ferrite layer
108
includes first and second coil segments
110
,
112
mounted on the upper surface thereof. Coil segments
110
,
112
include inner ends
114
,
116
respectively and outer ends
118
,
120
respectively. The third ferrite layer
108
also includes via holes
122
,
124
which are registered below the outer ends
118
and
120
respectively of the coil segments
110
,
112
. Within the via holes
122
,
124
are a first via fill
126
and a second via fill
128
which provide electrical connection between the outer ends
118
,
120
, of coil segments
110
,
112
and the outer ends
96
,
98
of coil segments
88
,
90
respectively.
A fourth ferrite layer
130
includes first and second coil segments
132
,
134
thereon. Each of the coil segments includes an inner end
136
,
138
respectively and an outer end
142
,
140
respectively. Registered below the inner end
136
is a first via opening
144
and registered beneath the inner end
138
is a second via opening
146
. Via openings
144
,
146
are filled with conductive via fills
148
,
150
respectively. Via fills
148
,
150
provide electrical connection between the inner end
136
of coil segment
132
and the inner end
114
of coil segment
110
and also provide communication between the inner end
138
of coil segment
134
and the inner end
116
of coil segment
112
.
A cap ferrite layer
152
includes a first terminal
154
and a second terminal
156
imprinted thereon. A first cap via opening
158
is registered below first terminal
154
and a second cap via opening
160
is registered below second terminal
156
. Via fills
162
,
164
are mounted within the via holes
158
,
160
and provide electrical communication between terminals
154
,
156
and outer ends
142
,
140
respectively of coil segments
132
,
134
. The number of layers of coil segments may be increased or decreased according to the inductance desired. Also, the terminals
154
,
156
may be located on the top sides, or on combinations of surfaces of inductor body
72
without detracting from the invention.
FIG. 4
illustrates schematically the side-by-side coil configuration which is formed by the structure shown in FIG.
3
. The coil commences at terminal
154
and progresses helically downwardly to coil segment
76
. It then connects by means of connector segment
80
to the bottom coil segment
78
and progresses helically upwardly to the terminal
156
. Preferably coil segments
132
,
110
,
88
,
76
are all rectangular or circular in configuration and are not elongated or ovular or rectangular as in prior art devices. Similarly, the configurations
78
,
90
,
112
,
134
are all circular or square in configuration and are not ovular, elongated or rectangular as in prior art devices. However, other configurations may be used for the coil segments including rectangular configurations. Using square or circular coil segments maximizes inductance.
Each of the coil segments is shown as progressing slightly further then 360° within the segment. However, the particular configuration may vary and the number of degrees in each coil segment can vary without detracting from the invention. The number of degrees in each coil segment can be greater than 360° or less than 360° as desired.
The assembled inductor
72
is shown in FIG.
5
. If desired a dielectric coating may be used to cover the inductor
72
, but leaving terminals
154
,
156
exposed. Inductor
72
is rectangularly shaped. The rectangular shape makes possible the robotic assembly of the inductor assembly
72
into an electrical circuitry because the robotic equipment can sense the rectangular shape of the inductance assembly
72
and orient it properly. Thus a rectangular overall inductance assembly is achieved, while at the same time achieving the maximum inductance obtainable with a square or circular configuration within each coil segment.
The preferred implementation of the present invention may utilize a multilayer ceramic build-up technique such as thick film or low temperature cofired tape. The body is composed of a ferrite material while the conductive coil material is preferably silver or silver/palladium. The same results could be achieved by utilizing other thick film body materials and conductor materials as well as completely different techniques like traditional copper wire coil winding techniques used in molded bodies.
In the drawings and specification there has been set forth a preferred embodiment of the invention, and although specific terms are employed, these are used in a generic and descriptive sense only and not for purposes of limitation. Changes in the form and the proportion of parts as well as in the substitution of equivalents are contemplated as circumstances may suggest or render expedient without departing from the spirit or scope of the invention as further defined in the following claims.
Claims
- 1. A side by side coil inductor comprising:a first coil comprising a plurality of conductive first coil segments positioned one above the other, said first coil segments being connected together in series; a second coil comprising a plurality of conductive second coil segments positioned one above the other, said second coil segments being connected together in series; said first and second coil being in side by side position relative to one another and being connected together in series; a top ferrite layer; a bottom ferrite layer; at least one middle ferrite layer between the top ferrite layer and the bottom ferrite layer; each of the at least one middle ferrite layer having a first via hole for connecting first coil segments in series and a second via hole for connecting second coil segments in series; and each of the at least one middle ferrite layers being separated from adjacent ferrite layers only by first coil segments and second coil segments.
- 2. A side by side coil inductor according to claim 1 wherein said first and second coils in combination have a combined length dimension and a combined width dimension, said combined length dimension being greater than said combined width dimension.
- 3. A side by side coil inductor according to claim 2 wherein a plurality of ferrite layers and said first and second coils form a body member, said body member having a body length dimension and a body width dimension, said body length dimension being greater than said body width dimension.
- 4. A side by side coil inductor according to claim 1 wherein said first coil and said second coil each have a coil width dimension and a coil length dimension which are equal.
- 5. The side-by-side coil inductor of claim 1 wherein the first and second coil segments being formed by a thick film process.
- 6. The side-by-side coil inductor of claim 1 wherein each of the coil segments progresses more than 360 degrees.
- 7. The side-by-side inductor of claim 1 wherein the first and second coil segments being formed by low temperature cofired tape.
- 8. A side by side coil inductor comprising:a first helically shaped conductor coil having a plurality of first coil layers stacked above one another; a second helically shaped conductor coil having a plurality of second coil layers stacked above one another; each of said first and second conductor coils having horizontal length and width which are equal; each of said first and second conductor coils being in side by side relation and being connected in series with one another; a plurality of ferrite layers alternating between adjacent pairs of said first coil layers and between adjacent pairs of said second coil layers to create an inductor body having an elongated shape with a body length greater than a body width; each of said first coil layers connected in series through at least one first coil layer via; each of said second coil layers connected in series through at least one second coil layer via; and each of the plurality of ferrite layers being separated from at least one adjacent ferrite layer only by first coil segments and second coil segments.
- 9. The side-by-side coil inductor of claim 8 wherein the first and second coil segments being formed by a thick film process.
- 10. The side-by-side coil inductor of claim 8 wherein each of the coil segments progresses more than 360 degrees.
- 11. The side-by-side coil inductor of claim 8 wherein the first and second coil segments being formed by low temperature cofired tape.
US Referenced Citations (16)
Foreign Referenced Citations (2)
Number |
Date |
Country |
0310396 |
Apr 1989 |
EP |
5-347213 |
Dec 1993 |
JP |