U.S. patent number 3,874,075 [Application Number 05/410,237] was granted by the patent office on 1975-04-01 for method for the production of an inductive component element.
This patent grant is currently assigned to Siemens Aktiengesellschaft. Invention is credited to Hartwig Lohse.
United States Patent |
3,874,075 |
Lohse |
April 1, 1975 |
Method for the production of an inductive component element
Abstract
A method for producing an inductive component element in which a
magnetic core is covered at least partially with a non-magnetic,
metallic layer which is thereafter impacted with a laser beam to
partially sever selected portions of the metallic layer from other
portions thereof to the finally generally helically shaped
inductive coil, a layer of insulating material being interposed
between the metallic layer and the magnetic core if the latter is
constructed of a magnetic material having insufficient insulating
properties.
Inventors: |
Lohse; Hartwig (Regensburg,
DT) |
Assignee: |
Siemens Aktiengesellschaft
(Berlin and Munich, DT)
|
Family
ID: |
5860541 |
Appl.
No.: |
05/410,237 |
Filed: |
October 26, 1973 |
Foreign Application Priority Data
|
|
|
|
|
Oct 31, 1972 [DT] |
|
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2253412 |
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Current U.S.
Class: |
29/602.1;
336/200; 427/127; 219/121.85; 336/229; 427/287 |
Current CPC
Class: |
H01F
17/04 (20130101); B23K 26/40 (20130101); H01F
41/046 (20130101); B23K 2103/50 (20180801); Y10T
29/4902 (20150115) |
Current International
Class: |
H01F
41/04 (20060101); H01F 17/04 (20060101); B23K
26/00 (20060101); B23K 26/40 (20060101); H01f
007/06 () |
Field of
Search: |
;29/602,625,605
;336/200,221,223,233,229 ;219/121L,121LM ;117/45,212,234 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Hall; Carl E.
Attorney, Agent or Firm: Hill, Gross, Simpson, Van Santen,
Steadman, Chiara & Simpson
Claims
I claim as my invention:
1. A method for the production of an inductive component element,
comprising the steps of applying a non-magnetic layer to and at
least partially covering a magnetic core of rectangular,
ring-shaped configuration having generally oppositely disposed
faces connected by respective edge portions, and impacting the
layer with a laser beam, incident at an angle of less than
90.degree., to partially sever selected portions of the layer from
other portions thereof on both the faces and adjoining edge
portions, and thereby define a generally helically shaped inductive
coil.
2. A method according to claim 1, comprising the further step of
applying an insulating intermediate layer directly upon the
magnetic core prior to the application of said metallic layer.
3. A method according to claim 1, wherein a selected base and edge
portions are initially impacted, the core rotated through
180.degree. about an axis operative to correspondingly dispose the
other face of the core and corresponding edge portions for beam
impact, and thereafter impacting the last-mentioned face and edge
portions with said laser beam.
4. A method for the production of an inductive component element,
comprising the steps of applying a non-magnetic metallic layer to
and at least partially covering a magnetic core of ring-like
configuration, comprising a pair of spaced longitudinally extending
side portions connected at their ends by respective transversely
extending side portions, impacting the layer with a laser beam to
partially sever selected portions of the layer from other portions
thereof, while advancing the core in the direction of the
longitudinal side portions (Y-direction) by an amount to provide a
desired spiral pitch, and reciprocating back and forth in the
direction of its transverse side portions (X-direction) by an
amount which is greater than the width of the longitudinal side
portions, subsequently rotating the ring core 180.degree. about an
axis in the X-Y plane, and repeating such advancing and
reciprocating steps while impacting the core, whereby the metallic
layer is divided into a generally helically shaped inductive coil
by the action of said laser beam.
5. A method according to claim 4, comprising impacting the metallic
layer with such laser beam at an angle of approximately 45.degree.
with respect to the XY-plane and at an angle with respect to the X-
or Y-axis, respectively, at an angle determined by the ring core
thickness and the desired spiral pitch.
6. A method according to claim 5, comprising the further step of
applying an insulating intermediate layer directly upon the
magnetic core piror to the application of said metallic layer.
Description
BACKGROUND OF THE INVENTION
The invention is directed to a method of producing an inductive
component element, particularly a miniature coil, electrical choke,
or transformer.
With the continual demands for reduction in size of electronic
components, and miniaturization of equipment, a strong need arises
for the production of extremely small inductive elements. It will
be apparent that with the greater and greater reduction in size of
such components physical winding of such components becomes wholly
impractical and the present invention is therefore directed to the
problem of achieving a method by means of which inductive component
elements of even extremely small dimensions can be produced with
relatively simple procedures without the necessity of effecting one
or more physical windings on a ring core or similar structure.
SUMMARY OF THE INVENTION
The present invention achieves the desired results by the
utilization of a magnetic core of suitable size and shape, at least
partially covered with a non-magnetic metallic layer, which, for
example, may be readily formed by chemical precipitation, vapor
deposition or similar method, with such metallic layer being
impacted by a laser beam to partially sever selected portions of
the layer from other portions thereof and thereby define a
generally helically shaped inductive coil.
If the magnetic material employed for the core structure possess
adequate insulating characteristics, the metallic layer may be
directly applied to such core structure. However, if the insulating
characteristics of a magnetic material employed are unsuitable for
direct application of the metallic layer thereto, the core
structure may be provided with a suitable layer of organic or
inorganic insulating material upon which the metallic layer is
subsequently applied.
If desired, in the production of transformers, following the
formation of a first coil or winding by means of a metallic layer,
such coil may have super-imposed thereon an insulating layer upon
which a subsequent metallic layer is applied and by means of a
laser beam partially divided or severed into one or more additional
coils or windings. A suitable magnetic core for this purpose may,
for example, be in the form of a magnetic ring core, advantageously
of rectangular configuration which is covered with a non-magnetic
metallic layer and is severed into a coil or winding by means of
laser beam incident at an inclination, i.e., an angle less than
90.degree..
The metallically covered ring core, comprising longitudinally and
transversely extending connecting side portions or sections, can,
for example, be impacted by a laser beam, while relative advancing
movement is effected therebetween in the direction of the
longitudinal portions (y-direction) by an amount equal to a single
spiral pitch and can be advanced in a direction of its transverse
portions (x-direction) by an amount which is somewhat greater than
the width of the longitudinal portions, following which the ring
core may be rotated through 180.degree., and the advancing
operations repeated, whereby the metallic layer is severed or
divided into a helical or coil formation.
Advantageously, the laser beam may impact upon the metallic layer
at an angle of about 45.degree. with respect to the xy-plane and at
an angle with respect to the x and y axes in dependence upon the
ring core thickness and the desired spiral pitch.
The method of the invention is also suitable for the simultaneous
production of a plurality of ring cores, each of which is provided
with a helically shaped metallic layer and by means of the method a
miniature inductance of extremely small dimensions can be produced,
which can be processed either in the form of chips, or, by means of
stacking, formed into an assembly of cores to form a unit with
relatively high inductivity. Advantageously, the beginning and end
portions of the helical winding of the ring core may be so
positioned that a desired series connection of the individual
inductances will automatically occur as a result of such stacking
or arranging in layers of the individual inductive components.
The invention is also applicable to the production of inductances
employing rod-shaped magnetic cores which can be rotationally
symmetrical or non-symmetrical, and which can be covered with a
non-magnetic layer and severed or divided into helical-shaped coil
by the impact of the laser beam which may be incident at an
inclination. The magnetic core and the laser beam may be
advantageously rotated relatively to one another and longitudinal
advancement effected in longitudinal direction of the core, to
provide a coil of desired configuration.
In the event the coils or windings of either the rod-shaped
magnetic cores or the ring cores are to be traversed by greater
current intensities, for example, during interference elimination,
the metallic layer applied upon the core can be built-up or
reinforced galvanically, i.e., by an electro-plating operation
which can take place either prior to or subsequent to the severance
or division of the metallic layer into a helically shaped coil. Any
necessary balancing or adjustment of the inductance or a component
so formed may be readily achieved by the use of generally known
soldered areas or sections, by means of which one or more turns of
a coil may be short-circuited or left free of solder until the
desired inductivity is achieved. Likewise, assemblies of several
rectangularly shaped flat ring cores may be suitably balanced as to
inductivity by means of short-circuiting of desired turns by a
suitable contact piece or member disposed, for example, in the
rectangular opening or perforation of the ring core.
A balancing or desire shifting of the inductivity of the magnetic
flow in the ring core can also be achieved by the formation of a
groove or a notch in a section or portion of a core which does not
carry a winding. In this case, it is unimportant whether the groove
is created by means of a laser beam, electronic beam, sandblasting,
grinding or other suitable method. The groove can extend on one
side or on several sides and can reach a defined depth which may
even lead to a complete separation thereat.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings, wherein like reference characters indicate like or
corresponding parts:
FIG. 1 is a simplified perspective view of an inductive component
element constructed in accordance with the present invention, and
illustrating in simplified schematic manner the method of
production; and
FIG. 2 is a similar figure illustrating in schematic form the
manner in which the method of the invention is applicable to mass
production.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Referring to FIG. 1, there is illustrated a small rectangular
plate-like magnetic ring core 1 which is covered with a metallic
layer 2 and includes contact areas 3 and 4. The core 1 is suitably
advanced by a reciprocating movement in the direction of the arrow
B in Y direction by an amount corresponding to the desired spiral
pitch, and is suitably advanced by reciprocation in the direction
of arrow A, i.e., X direction, by an amount which is somewhat
greater than the width of the longitudinal sections or longer leg
portions of the ring core. The metallic layer 2 is suitably severed
or divided into winding turns 5 under the action of a sharply
focused beam 7 of a laser device 8, only schematically represented
in these FIGS. The laser beam 7 is preferably inclined to the XY
plane at an angle of 45.degree. with the component of the laser
beam 7 projected on the XY plane being inclined to the X or Y axes
respectively at an angle which is determined by the thickness of
the ring core 1 and the desired spiral pitch. After completion of
the separating operation of the lateral areas of the metallic layer
2, as illustrated in FIG. 1, the ring core may be rotated
180.degree. and the advancing and severing operations repeated. As
illustrated in FIG. 1, one or more winding turns of the coil can be
short-circuited by a soldered section or area 6, illustrated as
disposed on an edge portion of the core, to enable balance or
adjustment of the inductivity. Such balancing or adjustment may
also be achieved by the utilization of a suitable contact piece or
member which bridges portions one or more winding turns of the
coil.
As illustrated in FIG. 2, the invention is applicable to the mass
production of inductances. In this case a plurality of ring cores
may be fabricated as an integral structure with adjacent cores
being separated from one another by respective grooves or notches
10 at which the cores may be broken or separated from one another.
The severing or division of the respective metalized areas into
respective winding turns 5 may be performed for one side of all of
the cores, in a manner previously described, following which the
connected cores may be rotated and the operations performed on the
opposite sides thereof in the manner previously described.
Likewise, the openings or perforations 11 can also be constructed
as so-called breaking slots or the like.
It will be appreciated that by the use of the present method,
employing a sharply defined laser beam, extremely fine coils or
windings can be produced whereby the resulting inductance may have
exceedingly small dimensions, and by the use of a stacking
operation coils of greater inductivity may be produced.
Having thus described my invention it is obvious that although
minor modifications might be suggested by those skilled in the art,
it should be understood that I wish to embody within the scope of
the patent warranted hereon all such modifications as reasonably
come within the scope of my contribution to the art.
* * * * *