U.S. patent application number 13/088913 was filed with the patent office on 2011-11-03 for diffusion bonded lead connector.
This patent application is currently assigned to Medtronic, Inc.. Invention is credited to Darren A. Janzig, Gerald G. Lindner, Chris J. Paidosh, Andrew J. Thom, Brad C. Tischendorf.
Application Number | 20110270330 13/088913 |
Document ID | / |
Family ID | 44858872 |
Filed Date | 2011-11-03 |
United States Patent
Application |
20110270330 |
Kind Code |
A1 |
Janzig; Darren A. ; et
al. |
November 3, 2011 |
DIFFUSION BONDED LEAD CONNECTOR
Abstract
A medical device lead connector includes electrically conducting
contact rings spaced apart by an electrically insulating ring and
in axial alignment. The electrically conducting contact ring and
the insulating ring having an interface bond on an atomic
level.
Inventors: |
Janzig; Darren A.; (Center
City, MN) ; Thom; Andrew J.; (Maple Grove, MN)
; Paidosh; Chris J.; (St. Anthony, MN) ;
Tischendorf; Brad C.; (Minneapolis, MN) ; Lindner;
Gerald G.; (Lino Lakes, MN) |
Assignee: |
Medtronic, Inc.
Minneapolis
MN
|
Family ID: |
44858872 |
Appl. No.: |
13/088913 |
Filed: |
April 18, 2011 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61329260 |
Apr 29, 2010 |
|
|
|
Current U.S.
Class: |
607/2 ; 156/151;
156/60; 607/115 |
Current CPC
Class: |
C23C 14/18 20130101;
A61N 1/05 20130101; H01R 24/58 20130101; B23K 2101/38 20180801;
B23K 26/21 20151001; H01R 2107/00 20130101; H01R 2201/12 20130101;
B23K 20/026 20130101; B23K 2103/172 20180801; B23K 2103/52
20180801; A61B 2562/227 20130101; H01R 13/187 20130101; A61N 1/3752
20130101; C23C 14/10 20130101; Y10T 156/10 20150115; B23K 2103/54
20180801; C23C 14/34 20130101; H01R 43/0221 20130101 |
Class at
Publication: |
607/2 ; 607/115;
156/60; 156/151 |
International
Class: |
A61N 1/36 20060101
A61N001/36; B32B 38/00 20060101 B32B038/00; B32B 37/06 20060101
B32B037/06; B32B 37/14 20060101 B32B037/14; A61N 1/04 20060101
A61N001/04; B32B 37/02 20060101 B32B037/02 |
Claims
1. A medical device lead connector comprising: electrically
conducting contact rings spaced apart by an electrically insulating
ring and in axial alignment, and the electrically conducting
contact ring and the insulating ring having an interface bond on an
atomic level.
2. A medical device lead connector according to claim 1, wherein
the lead connector comprises a plurality of ring subassemblies
fixed in axial alignment and each ring subassembly comprises the
electrically insulating ceramic ring between an electrically
conducting contact ring and an electrically conducting spacer ring
bonded together with an interface bond on an atomic level.
3. A medical device lead connector according to claim 2, wherein
adjacent ring subassemblies are welded together to form a rigid
medical device lead connector.
4. A medical device lead connector according to claim 3, wherein
the interface bond on an atomic level is a diffusion bond.
5. A medical device lead connector according to claim 4, wherein
the electrically conducting contact ring comprises titanium or
titanium alloys and the electrically insulating ring comprises
sapphire or a ceramic material.
6. A medical device lead connector according to claim 5, wherein
the electrically conducting contact ring comprises titanium and the
electrically insulating ring comprises a metallization layer.
7. A medical device lead connector according to claim 6, wherein
the metallization layer comprises niobium, platinum, titanium or
combinations thereof.
8. An implantable medical device comprising: a hermetically sealed
housing defining a sealed housing interior; a power source and
electronics in electrical communication and disposed within the
sealed housing interior; and a lead connector projecting into the
sealed housing interior and having an outer surface, and an inner
surface defining a lead aperture, the lead connector comprising one
or more electrically conducting contact rings spaced apart by
electrically insulating rings and joined together with a diffusion
bond, the one or more electrically conducting contact rings in
electrical communication with the electronics, and the diffusion
bond providing a hermetic seal between the lead connector outer
surface and the lead connector inner surface.
9. An implantable medical device according to claim 8, wherein the
lead connector comprises a plurality of ring subassemblies fixed in
axial alignment, each ring subassembly comprises the diffusion bond
fixing an electrically insulating ring between an electrically
conducting contact ring and an electrically conducting spacer
ring.
10. An implantable medical device according to claim 9, wherein the
diffusion bond directly bonds the electrically conducting contact
ring and the electrically conducting spacer ring with the
electrically insulating ring.
11. An implantable medical device according to claim 10, wherein
adjacent ring subassemblies are welded together for form a rigid
lead connector.
12. An implantable medical device according to claim 11, wherein
the electrically conducting contact ring comprises titanium or
titanium alloys and the electrically insulating ring comprises
sapphire or a ceramic material.
13. An implantable medical device according to claim 12, wherein
the electrically conducting contact ring comprises titanium and the
electrically insulating ring comprises a metallization layer.
14. An implantable medical device according to claim 13, wherein
the metallization layer comprises niobium, platinum, titanium or
combinations thereof.
15. A method of forming a medical device lead connector comprising:
diffusion bonding an electrically insulating ring between a first
electrically conducting contact ring and a second electrically
conducting contact ring to form a joined element; and joining an
plurality of joined elements in axial alignment to form a lead
connector.
16. A method of forming a medical device lead connector according
to claim 15, wherein the joining step comprises welding a plurality
of joined elements in axial alignment to form a lead connector.
17. A method of forming a medical device lead connector according
to claim 15, wherein the joining step comprises diffusion bonding a
plurality of joined elements in axial alignment to form a lead
connector.
18. A method of forming a medical device lead connector according
to claim 17, further comprising sputtering a metallization layer
onto the electrically insulating ring before the diffusion bonding
step.
19. A method of forming a medical device lead connector according
to claim 18, wherein the diffusion bonding step occurs at a
temperature of less than 1000 degrees centigrade.
20. A method of forming a medical device lead connector according
to claim 19, further comprising placing the lead connector element
within a hermetic envelope of an active medical device.
21. A method of forming a medical device lead connector according
to claim 20, further comprising electrically connecting the lead
connector element to a feedthrough of an active medical device.
Description
[0001] The present application claims priority to U.S. Provisional
Patent Application No. 61/329,260, filed Apr., 29, 2010, which
application is hereby incorporated by reference as if re-written in
its entirety
BACKGROUND
[0002] Implantable active medical devices, such as cardiac rhythm
management devices (pacemakers and defibrillators) and a variety of
implantable muscle/nerve stimulators, for example, generally
include a battery and battery-powered electronic pulse generator
contained within a hermetically sealed housing or case and attached
to a lead connector housing or block. The lead connector block is
often affixed to the hermetically sealed housing with brackets,
and/or a medical grade adhesive.
[0003] The electronics within the hermetically sealed housing are
conductively coupled to the lead connector block with an electrical
feedthrough assembly. Electrical feedthroughs serve the purpose of
providing a conductive path extending between the interior of a
hermetically sealed container and a point outside the hermetically
sealed housing. The conductive path through the feedthrough usually
includes a conductor pin or terminal that is electrically insulated
from the hermetically sealed housing. Many such feedthroughs are
known in the art that provide the conductive path and seal the
electrical container from its ambient environment. Such
feedthroughs typically include a ferrule, and an insulative
material such as a hermetic glass or ceramic seal that positions
and insulates the pin within the ferrule. Sometimes it is desired
that the electrical device include a capacitor within the ferrule
and around the terminal, thus shunting any electromagnetic
interference (EMI) at high frequencies at the entrance to the
electrical device to which the feedthrough device is attached.
Typically, the capacitor electrically contacts the pin lead and the
ferrule. While this arrangement has proven to be highly reliable,
it involves a variety of expensive manufacturing processes and
parts that necessarily increase the cost of the resulting product
and increases the number of interconnects.
[0004] Ongoing efforts by the industry to reduce the size of the
implantable device are desired. With advances in microelectronics
and integrated circuitry, significantly more features and
capabilities have been embodied in implantable active medical
devices capable of sizes as small as about 10 cc. Nonetheless,
efforts to further reduce the size of implantable active medical
devices continue in the industry.
BRIEF SUMMARY
[0005] The present disclosure relates to diffusion bonded lead
connectors. In particular the present disclosure relates to
hermetic lead connectors that have contact portions separated by an
insulating ring and joined together with an interface bond on an
atomic level. The interface bond on an atomic level can be a solid
state diffusion bond (i.e., diffusion bond) that forms a hermetic
bond with the electrically insulating portions and electrically
conducting contact portions of the hermetic lead connectors.
[0006] In one illustrative embodiment, a medical device lead
connector includes electrically conducting contact rings spaced
apart by an electrically insulating ring and in axial alignment.
The electrically conducting contact ring and the insulating ring
having an interface bond on an atomic level.
[0007] In another illustrative embodiment, an implantable medical
device includes a hermetically sealed housing defining a sealed
housing interior, a power source and electronics in electrical
communication and disposed within the sealed housing interior, and
a lead connector projecting into the sealed housing interior. The
lead connector has an outer surface, and an inner surface defining
a lead aperture. The lead connector includes one or more
electrically conducting contact rings spaced apart by electrically
insulating rings and joined together with a diffusion bond. The one
or more electrically conducting contact rings are in electrical
communication with the electronics. The diffusion bond provides a
hermetic seal between the lead connector outer surface and the lead
connector inner surface.
[0008] In a further embodiment, a method of forming a medical
device lead connector includes diffusion bonding an electrically
insulating ring between a first electrically conducting contact
ring and a second electrically conducting contact ring to form a
joined element and then joining a plurality of joined elements in
axial alignment to form a lead connector.
[0009] These and various other features and advantages will be
apparent from a reading of the following detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The disclosure may be more completely understood in
consideration of the following detailed description of various
embodiments of the disclosure in connection with the accompanying
drawings, in which:
[0011] FIG. 1 is a schematic diagram of a an active medical device
implanted within a human body;
[0012] FIG. 2 is a schematic perspective view of an implantable
active medical device with an internal hermetic lead connector;
[0013] FIG. 3 is a schematic perspective view of an illustrative
lead connector with an external lead connector;
[0014] FIG. 4 is a perspective schematic diagram view of an
illustrative lead connector;
[0015] FIG. 5 is an perspective cut-away view of the illustrative
lead connector shown in FIG. 4;
[0016] FIG. 6 is a perspective cut-away view of one of the
illustrative lead connector sub-assemblies shown in FIG. 5; and
[0017] FIG. 7 is a flow diagram of an illustrative method of making
a lead connector element.
[0018] The figures are not necessarily to scale. Like numbers used
in the figures refer to like components. However, it will be
understood that the use of a number to refer to a component in a
given figure is not intended to limit the component in another
figure labeled with the same number.
DETAILED DESCRIPTION
[0019] In the following description, reference is made to the
accompanying set of drawings that form a part hereof and in which
are shown by way of illustration several specific embodiments. It
is to be understood that other embodiments are contemplated and may
be made without departing from the scope or spirit of the present
disclosure. The following detailed description, therefore, is not
to be taken in a limiting sense.
[0020] Unless otherwise indicated, all numbers expressing feature
sizes, amounts, and physical properties used in the specification
and claims are to be understood as being modified in all instances
by the term "about." Accordingly, unless indicated to the contrary,
the numerical parameters set forth in the foregoing specification
and attached claims are approximations that can vary depending upon
the desired properties sought to be obtained by those skilled in
the art utilizing the teachings disclosed herein.
[0021] As used in this specification and the appended claims, the
singular forms "a", "an", and "the" encompass embodiments having
plural referents, unless the content clearly dictates otherwise. As
used in this specification and the appended claims, the term "or"
is generally employed in its sense including "and/or" unless the
content clearly dictates otherwise.
[0022] Spatially related terms, including but not limited to,
"lower", "upper", "beneath", "below", "above", and "on top", if
used herein, are utilized for ease of description to describe
spatial relationships of an element(s) to another. Such spatially
related terms encompass different orientations of the device in use
or operation in addition to the particular orientations depicted in
the figures and described herein. For example, if an element
depicted in the figures is turned over or flipped over, portions
previously described as below or beneath other elements would then
be above those other elements.
[0023] As used herein, when an element, component or layer for
example is described as being "on" "connected to", "coupled with"
or "in contact with" another element, component or layer, it can be
directly on, directly connected to, directly coupled with, in
direct contact with, or intervening elements, components or layers
may be on, connected, coupled or in contact with the particular
element, component or layer, for example. When an element,
component or layer for example is referred to as begin "directly
on", "directly connected to", "directly coupled with", or "directly
in contact with" another element, there are no intervening
elements, components or layers for example.
[0024] The present disclosure relates to hermetic diffusion bonded
lead connectors. In particular the present disclosure relates to
hermetic lead connectors that have electrically conducting contact
portions separated by electrically insulating portions and
diffusion bonded together. The diffusion bond forms a hermetic bond
with the electrically conducting contact portions and the
electrically insulating portions of the hermetic lead connectors.
The diffusion bond eliminates gold or metal brazing material from
the hermetic lead connector and thus the manufacturing temperatures
of the hermetic lead connector is reduced, in many embodiments, to
less than 1000 degrees centigrade. In addition, the diffusion bond
allows the electrically conducting contact portions of the hermetic
lead connector to be closer than has been conventionally available.
For example, the pitch between electrical contact portions can be
reduced to 0.085 inch or less. Utilizing diffusion bonding provides
a number of advantages such as reducing the manufacturing
temperature and reducing the size of the hermetic lead connectors,
for example. While the present disclosure is not so limited, an
appreciation of various aspects of the disclosure will be gained
through a discussion of the examples provided below.
[0025] FIG. 1 is a schematic diagram of an active medical device 20
implanted within a human body or patient 28. The implanted active
medical device 20 is illustrated as a neurostimulator, however, the
implanted active medical device 20 can be any "active implantable
medical device" or "implantable signal generator" as described
above and can be placed in any location within a body cavity or
tissue within the body, or on the surface of a patient's skin, as
desired. In some embodiments the device is a non-active implantable
medical device such as a sensor, for example.
[0026] The active medical device 20 is coupled to a lead extension
22 having a proximal end coupled to the active medical device 20,
and a lead 24 having a proximal end coupled to a distal end 32 of
the lead extension 22 and a distal end of the lead 24 coupled to
one or more electrodes 26. In other embodiments, the lead 24
proximal end is coupled to the active medical device 20, without a
need for a lead extension 22. The active medical device 20 can be
implanted in any useful region of the body such as in the abdomen
of a patient 28, and the lead 24 is shown placed somewhere along
the spinal cord 30. In many embodiments, the active medical device
20 has one or two leads each having four to eight electrodes. Such
a system may also include a physician programmer and a patient
programmer (not shown). The active medical device 20 can be
considered to be an implantable signal generator of the type
available from Medtronic, Inc. and capable of generating multiple
signals occurring either simultaneously or one signal shifting in
time with respect to the other, and having independently varying
amplitudes and signal widths. The active medical device 20 contains
a power source and the electronics for sending precise, electrical
signals to the patient to provide the desired treatment therapy.
While the active medical device 20, in many embodiments, provides
electrical stimulation by way of signals, other forms of
stimulation may be used as continuous electrical stimulation.
[0027] In many embodiments, the lead 24 is a wire having insulation
thereon and includes one or more insulated electrical conductors
each coupled at their proximal end to a connector and to
contacts/electrodes 26 its distal end. Some leads are designed to
be inserted into a patient percutaneously (e.g. the Model 3487A
Pisces-Quad.RTM. lead available from Medtronic, Inc.), and some are
designed to be surgically implanted (e.g. Model 3998 Specify.RTM.
lead, also available from Medtronic, Inc.). In some embodiments,
the lead 24 may contain a paddle at its distal end for housing
electrodes 26. In many embodiments, electrodes 26 may include one
or more ring contacts at the distal end of lead 24.
[0028] FIG. 2 is a schematic perspective view of an implantable
active medical device 102. FIG. 3 is a schematic cut-away
perspective view of an implantable active medical device header 202
with an external hermetic lead connector. Thus the disclosed lead
connector 105 can be utilized in a conventional device that relies
on a feedthrough 203 to provide the hermetic barrier (see FIG. 3)
or the disclosed lead connector 105 can be utilized to provide the
hermetic barrier extending into a device (see FIG. 2). FIG. 3 does
not show the hermetic enclosure for the electronics and power
source, but it is understood that the hermetic enclosure would be
adjacent to the feedthrough 203. FIG. 3 does not rely on the
disclosed lead connector 105 to provide the device hermetic
barrier, however the disclosed lead connector 105 provides a rigid
lead connector with electrical contacts at a fixed pitch.
[0029] The active medical device 102 includes a hermetically sealed
housing 109 defining a sealed housing interior. The active medical
device 102 is illustrated without a cover portion that would
complete the hermetic sealed housing 109. A power source 21 and
electronics 23 are in electrical communication and are disposed
within the sealed housing 109 interior. A lead connector 105
projects into and through the sealed housing 109 interior and has
an inner surface or lead receptacle defining an open lumen lead
aperture 165. In many embodiments an outer surface of the lead
connector 105 at least partially defines the sealed housing
interior surface.
[0030] A "diffusion bond" refers to technique of bonding materials
in the solid state to form a monolithic joint through the formation
of bonds at an atomic level, as a result of closure of the mating
surfaces due to the local plastic deformation at elevated pressure
and temperature which aids interdiffusion at the surface layers of
the materials being joined. Solid-state diffusion bonding is a
process by which two nominally flat interfaces can be joined at an
elevated temperature (about 50 to 90% of the absolute melting point
of the parent material) using an applied pressure for a time
ranging from a few minutes to a few hours. Joining of dissimilar
materials with different thermo-physical characteristics, which is
not possible by other processes, may be achieved by diffusion
bonding. Metal, alloys, ceramics and powder metallurgy products can
be joined by diffusion bonding. A diffusion bond forms a hermetic
seal.
[0031] FIG. 4 is a perspective schematic diagram view of an
illustrative lead connector 105. FIG. 5 is a perspective cut-away
view of the illustrative lead connector 105 shown in FIG. 4. FIG. 6
is a perspective cut-away view of one of the illustrative lead
connector sub-assemblies shown in FIG. 5.
[0032] The lead connector 105 includes one or more electrically
conducting contact rings 130 spaced apart by electrically
insulating ring 140 and in axial alignment. An interface bond on an
atomic level joins the electrically insulating ring 140 to the
electrical contact ring 130. As illustrated, the electrically
insulating ring 140 is joined (via a diffusion bond) between two
electrical contact rings 130, 130'. These two electrical contact
rings 130, 130' can also be referred to as an electrical contact
ring 130 and an electrical spacer ring 130'. These three elements
(two electrical contact rings 130, 130' and the electrically
insulating ring 140) form a subassembly 106 that can be welded
together at abutting electrical contacts 130, 130' to form the lead
connector 105.
[0033] The one or more electrically conducting contact rings 130,
130' can be formed as a single element (not shown) or can include
another electrically conducting contact ring that can be welded to
the electrically conducting contact ring 130 to form the one or
more electrically conducting contact rings 130, 130' as illustrated
in the sub-assembly manufacture process described herein.
[0034] The one or more electrically conducting contact rings 130,
130' are in electrical communication with the electronics 23 and
the lead connector 105 provides a hermetic seal between the sealed
housing 109 interior and the lead aperture 165. The electronics 23
generally control the active medical device 102. The power source
21 can be any useful battery or power source such as an inductive
coil. In some embodiments, the electronics 23 includes memory. The
memory can be any magnetic, electronic, or optical media, such as
random access memory (RAM), read-only memory (ROM),
electronically-erasable programmable ROM, flash memory, or the
like.
[0035] The one or more electrically conducting contact rings 130,
130' can be formed of any useful electrically conductive material.
In many embodiments, the one or more electrically conducting
contact rings 130, 130' are formed of a metallic material such as,
for example, titanium, stainless steel, MP35N, niobium, tantalum,
platinum, and alloys or combinations thereof. In some embodiments,
the one or more electrically conducting contact rings 130, 130' are
formed of a metallic material such as, for example, titanium or
titanium alloy.
[0036] The electrically insulating ring 140 can be formed of any
useful electrically insulating material. In many embodiments the
electrically insulating ring 140 is formed of ceramic or sapphire.
In some embodiments the electrically insulating ring 140 is formed
of polycrystalline aluminum oxide. In some embodiments a
metallization layer 141, 142 is sputter coated (for example) on the
electrically insulating ring 140 to assist the formation of the
diffusion bond. The metallization layer 141, 142 can be formed of
any useful material. In some embodiments, the metallization layer
141, 142 is formed of niobium, rhodium, hafnium or tantalum,
titanium and platinum. In some embodiments a metallization layer
141, 142 includes niobium, platinum, titanium or combinations
thereof. The metallization layer 141, 142 can have any useful
thickness. In some embodiments, the metallization layer 141, 142
has a thickness of less than 3 micrometer or is in a range from 10
nanometers to 1 micrometer. In many embodiments the metallization
layer 141, 142 covers only a portion of the electrically insulating
ring 140, specifically at the diffusion bond interface. In some
embodiments the metallization layer 141, 142 is sputter coated (for
example) on the electrically conducting contact rings 130, 130' in
addition to or instead of the electrically insulating ring 140.
[0037] In some embodiments, the electrically conducting contact
rings 130, 130' are formed of titanium and the electrically
insulating ring 140 is formed of ceramic or sapphire. These
elements can be joined via diffusion bonding at a temperature that
is less than the phase transition temperature of titanium. For
example, the elements can be placed under pressure of 1-5 MPa and
processed at a temperature in a range from 800 to 1000 degrees
centigrade or in a range from 850 to 950 degrees centigrade. These
temperatures are less than the melting point of gold, for example.
Also the pitch between electrical contact portions 130 or contact
coils 150 can be reduced to 0.085 inch or less. Diffusion bonding
can also improve the process control and reduce pitch variation as
compared to other joining techniques.
[0038] In some embodiments, a filtering capacitor is disposed
between the electrically conducting contact rings 130, 130' and the
electronics 23. The filtering capacitor can effectively filter out
undesirable electromagnetic interference (EMI) from the active
medical device 102.
[0039] The implantable active medical device described herein can
eliminate the need for a conventional separate feedthrough block
that electrically connects a conventional lead connector block with
the hermetically sealed electronics of the implantable active
medical device. By placing the lead connector within the
hermetically sealed active medical device housing, a direct
electrical connection between the lead connector and the
electronics can be made (as illustrated in FIG. 2). In addition,
combining the feedthroughs and the external connector into a single
component can reduce the size and volume of the implantable medical
device and can also reduce the number of parts and connections
needed to assemble the implantable active medical device.
[0040] The illustrated lead connector 105 is an elongate member
extending between a lead aperture 165, first open end 166, and end
cap 145, and having an inner surface defining an open lumen lead
aperture 165. In some embodiments the lead connector 105 is an
elongate member extending between a lead aperture 165, first open
end 166 and second open end (not shown). The open lumen lead
aperture 165 or lead receptacle 165 is configured to accept a lead
or lead extension, as described above, and electrically couple one
or more lead contacts with one or more connector contacts 130, 130'
that form the elongate body of the lead connector 105, that in many
embodiments is generally cylindrical.
[0041] In many embodiments, the lead aperture 165 is a cylindrical
open lumen of generally circular cross-sectional area formed by an
inner surface of the electrically conducting rings 130, 130' and
electrically insulating rings 140 diffusion bonded together in
axial alignment. The lead connector 105 defines a lead connector
outer surface 170 and at least a portion of the lead connector
outer surface 170 is disposed within the sealed housing 109
interior. In many embodiments, at least a majority of the lead
connector outer surface 170 is disposed within the sealed housing
109 interior. In many embodiments, substantially the entire lead
connector outer surface 170 is disposed within the sealed housing
109 interior and at least partially defines the sealed housing 109
interior. In some embodiments, the entire lead connector outer
surface 170 is disposed within the sealed housing 109 interior.
[0042] The one or more electrically conducting contact rings 130,
130' can include one or more additional contact elements in
electrical contact with and optionally disposed within each of the
one or more electrically conducting contact rings 130, 130'. These
one or more additional contact elements are configured to provide
electrical communication between one or more electrically
conducting contact rings 130, 130' and a lead contact received
within the lead aperture 165. In many embodiments, these contact
elements are electrically conductive and resilient to provide an
interference fit between the electrically conducting contact ring
130, 130' and lead contact received within the lead aperture
165.
[0043] Examples of contact elements include, but are not limited
to, spring elements in many embodiments, the contact element
includes an annular helical coil 150 (i.e., continuous coil spring
150) is disposed adjacent an inner surface of the electrically
conducting contact ring 130 and/or 130, 130'. The helical annular
coil 150 can be formed of any useful electrically conductive
material such as, for example, a metal like gold, silver, titanium
and the like. When a lead is inserted into the lead aperture 165,
the lead and lead contact(s) can deflect the annular helical coil
150 and form an electrical contact between the lead contact and the
electrically conducting contact ring 130. The continuous coil
spring 150 provides a frictional electrical and mechanical
engagement with a lead contact and the adjacent electrically
conducting contact ring 130.
[0044] A mounting flange 160 can be fixed to the lead connector 105
adjacent the open end 166. The mounting flange 160 can be brazed or
welded, for example to the hermetically sealed housing 109. In some
embodiments, the mounting flange 160 is brazed or welded to an
exterior surface of the hermetically sealed housing 109. In other
embodiments, the mounting flanges 160 are brazed or welded to an
interior surface of the hermetically sealed housing 109. A
retention member (not shown) such as for example, a set screw, can
be disposed on the lead connector 105 adjacent to the open end 166
and can assist in mechanical retention of the lead disposed within
the lead aperture 165.
[0045] The lead connector 105 can be formed by any useful method.
In many embodiments, the lead connector 105 is formed by assembling
two or more lead connector subassemblies 106, described above. FIG.
6 is a cut-away perspective of the illustrative subassembly 106
shown in FIG. 4. Each lead connector subassembly 106 can be
arranged in axial alignment and bonded utilizing a metal-to-metal
bonding technique such as, laser welding or diffusion bonding, for
example, to form the lead connector 105.
[0046] Each lead connector subassembly 106 includes the
electrically insulating ring 140 fixed between the electrically
conducting contact ring 130 and an attachment ring or electrically
conducting spacer ring 130' via diffusion bonding. Thus, the
electrically conducting spacer ring 130' is diffusion bonded to a
first side of the electrically insulating ring 140 and the
electrically conducting contact ring 130 is diffusion bonded to a
second opposing side of the electrically insulating ceramic ring
140. The diffusion bond provides the hermetic seal between the
between the sealed housing interior/lead connector outer surface
170 and the lead aperture 165. In some embodiments, the subassembly
106 includes a wiper seal 178 that can assist in electrical
isolation of adjacent electrical contacts and also to mitigate
fluid transmission within the lead aperture.
[0047] FIG. 7 is a flow diagram of an illustrative method 250 of
making a lead connector element. The method includes diffusion
bonding an electrically conducting contact ring to an electrically
insulating ring to form a joined element at block 251. A plurality
of joined elements are then joined together to form the lead
connector element at block 252. The electrically insulating ring
can optionally be sputter coated to form a metallization layer
prior to the diffusion bonding.
[0048] Thus, embodiments of the DIFFUSION BONDED LEAD CONNECTOR are
disclosed. The implementations described above and other
implementations are within the scope of the following claims. One
skilled in the art will appreciate that the present disclosure can
be practiced with embodiments other than those disclosed. The
disclosed embodiments are presented for purposes of illustration
and not limitation, and the present invention is limited only by
the claims that follow.
* * * * *