ELECTRICAL FEEDTHROUGH

Abstract

An electrical feedthrough includes a base body having a first side and an opposed second side and at least one through-hole extending through the base body from the first side to the second side, an insulating material received in the through-hole, the insulating material having a first surface on the first side of the base body and an opposed second surface on the second side of the base body, and an electrical conductor extending through the insulating material, the electrical conductor having a first diameter at the location of the first surface of the insulating material and a second diameter at the location of the second surface of the insulating material, wherein the first diameter of the electrical conductor is larger than the second diameter of the electrical conductor.

Claims

1. An electrical feedthrough, comprising: a base body having a first side and an opposed second side and at least one through-hole extending through the base body from the first side to the second side; an insulating material received in the at least one through-hole, the insulating material having a first surface on the first side of the base body and an opposed second surface on the second side of the base body; and an electrical conductor extending through the insulating material, the electrical conductor having a first diameter at a location of the first surface of the insulating material and a second diameter at a location of the second surface of the insulating material, the first diameter of the electrical conductor being larger than the second diameter of the electrical conductor.

2. The electrical feedthrough according to claim 1, wherein at least one of: the electrical conductor one of (1) ends flush with the first surface of the insulating material on the first side of the base body and (2) is offset therefrom one of less than 500 μm, less than 250 μm, and less than 100 μm, such that the first surface of the insulating material one of is grinded flush with the electrical conductor and forms a meniscus which transitions flush to the electrical conductor; and the electrical conductor protrudes from the second surface of the insulating material on the second side of the base body, the protrusion being one of more than 500 μm and more than 1 mm.

3. The electrical feedthrough according to claim 1, wherein at least one of: the electrical conductor has a first section comprising a location of the first diameter and extending from the first surface of the insulating material into the insulating material, wherein the first section of the electrical conductor has a constant diameter; the electrical conductor has a second section comprising a location of the second diameter and extending from the second surface of the insulating material into the insulating material, wherein the second section of the electrical conductor has a constant diameter; and the electrical conductor has a tapered section between the location of the first diameter and the location of the second diameter, wherein the tapered section has a tapered diameter and wherein the tapered section is located between the first section and the section within the insulating material.

4. The electrical feedthrough according to claim 3, wherein at least one of: the electrical conductor has a length L between the location of the first diameter and the location of the second diameter, the length L being one of in a range of 0.2 mm to 10 mm, in a range of 0.3 mm to 5 mm, and in a range of 1 mm to 3 mm; at least one of the first section of the electrical conductor has a length L1 and the tapered section of the electrical conductor has a length L3, wherein one of the length L1, the length L3, and the length L1+the length L3 is one of at least 0.1 mm, at least 0.3 mm, and at least 0.6 mm; at least one of the first section of the electrical conductor has a length L1 and the tapered section of the electrical conductor has a length L3, wherein one of a ratio of the length L1/the length L, a ratio of the length L3/the length L, and a ratio of (the length L1+the length L3)/the length L one of is smaller than 0.7, is smaller than 0.5, and is smaller than 0.35; wherein the second section of the electrical conductor has a length L2, wherein a ratio of the length L2/the length L one of is larger than 0.3, is larger than 0.5, and is larger than 0.65; and the tapered section of the electrical conductor has a length L3, wherein a ratio of the length L3/the length L1 one of is between 1.25 and 3.0, between 1.5 and 2.5, and between 1.75 and 2.25.

5. The electrical feedthrough according to claim 3, wherein at least one of: a ratio of the first diameter to the second diameter of the electrical conductor is one of between 1.1 and 10, between 1.25 and 3.5, between 1.5 and 3.0, and between 1.75 and 2.75; the first diameter is one of at least 0.8 mm, at least 1 mm, and at least 1.5 mm; the second diameter is one of at most 1 mm, at most 0.8 mm, and at most 0.5 mm; the tapered section of the electrical conductor has a diameter tapering from the first diameter to the second diameter; and the tapered section of the electrical conductor has a linearly tapering diameter.

6. The electrical feedthrough according to claim 3, wherein the electrical conductor comprises a groove for a stronger mechanical interlock with the insulating material, wherein the groove is located in the second section of the electrical conductor.

7. The electrical feedthrough of claim 1, wherein the at least one through-hole is at least two through-holes, the base body including the at least two through-holes extending through the base body, wherein in each of the at least two through-holes a respective one of the insulating material is received, each respective one of the insulating material having a respective one of the first surface on the first side of the base body and a respective one of the opposed second surface on the second side of the base body, and wherein in each of the at least two through-holes a respective one of the electrical conductor extends through each respective one of the insulating material.

8. The electrical feedthrough according to claim 7, wherein at least one of: at least two of the electrical conductor extend through one of the and each of the insulating material; a distance between two of the electrical conductor is one of less than 50 mm, less than 10 mm, and less than 5 mm; a distance between two of the electrical conductor is one of more than 100 μm, more than 150 μm, and more than 200 μm; a distance between a respective one of the electrical conductor and the base body is one of less than 5 mm, less than 2 mm, and less than 1 mm; a distance between a respective one of the electrical conductor and the base body is more than 100 μm, more than 150 μm, and more than 200 μm; and a ratio of a surface area of a respective one of the insulating material received in a respective one of the through-hole and a surface area of one of a respective one of the electrical conductor and respective ones of the electrical conductor in the respective one of the through-hole on at least one of the first side and the second side of the base body is one of less than 15, less than 10, less than 5, and less than 4.

9. The electrical feedthrough according to claim 7, wherein at least one of: one of a respective one of the and each one of the electrical conductor has the first diameter at the location of the first surface of a respective one of the insulating material and the second diameter at the location of the second surface of a respective one of the insulating material; one of a respective one of the and each one of the through-hole has a diameter, which one of is constant throughout the base body and is tapered, within a range of 2° to 10°, having a maximum diameter; a ratio of the diameter/the first diameter of at least one of the through-hole one of is at most 1.5, is at most 1.3, is at most 1.2, and is at most 1.11; and a ratio of the diameter/the second diameter of at least one of the through-hole one of is at most 10, is at most 5, and is at most 2.5.

10. The electrical feedthrough according to claim 7, wherein each of the at least two through-holes has a respective diameter, which is constant throughout the base body, and wherein each of the at least two through-holes defines a half-distance diameter, the half-distance diameter being a distance within the base body between adjacent ones of the through-holes plus the diameter of the respective through-hole, and wherein a ratio of the half-distance diameter/the distance within the base body between adjacent ones of the through-holes of at least one of the through-holes one of is smaller than 2.0, is smaller than 1.8, is smaller than 1.7, is smaller than 1.6, is smaller than 1.5, is smaller than 1.4, is smaller than 1.3, is smaller than 1.2, and is smaller than 1.1.

11. The electrical feedthrough according to claim 1, wherein at least one of: the insulating material is under a contact pressure at the location of the second surface on the second side of the base body, wherein one of the contact pressure is a positive contact pressure, and the contact pressure at the location of the second surface on the second side is a negative contact pressure with an absolute value being one of less than 30 MPa, less than 20 MPa, less than 10 MPa, and less than 5 MPa; and the insulating material is under a contact pressure at the location of the first surface on the first side of the base body, wherein one of the contact pressure at the location of the first surface on the first side is a negative contact pressure with an absolute value being one of more than 1 MPa, more than 5 MPa, and more than 10 MPa.

12. The electrical feedthrough according to claim 1, wherein the insulating material is under a highest positive contact pressure with an absolute value which one of is lower than 155 MPa, is lower than 70 MPa, is lower than 50 MPa, is lower than 40 MPa, and is lower than 20 MPa.

13. The electrical feedthrough according to claim 1, wherein at least one of: the base body has a thermal expansion coefficient one of between 5×10.sup.−6K.sup.−1 and 25×10.sup.−6K.sup.−1 and 20×10.sup.−6K.sup.−1; the insulating material has a thermal expansion coefficient one of between 3×10.sup.−6K.sup.−1 and 15×10.sup.−6K.sup.−1 and between 5×10.sup.−6K.sup.−1 and 12×10.sup.−6K.sup.−1; the electrical conductor has a thermal expansion coefficient one of between 3×10.sup.−9K.sup.−1 and 25×10.sup.−6K.sup.−1 and between 5×10.sup.−6K.sup.−1 and 20×10.sup.−6K.sup.−1; the base body comprises at least one of the following materials: metal; austenitic stainless steel; a metal of AISI 300 series; ferritic stainless steel; a metal of AISI 400 series; titanium; inconel; duplex stainless steel; niobium; an alloy of one of austenitic stainless steel, a metal of AISI 300 series, ferritic stainless steel, a metal of AISI 400 series, titanium; inconel, duplex stainless steel, and niobium; and ceramic; the insulating material comprises at least one of the following materials: glass; glass ceramic; and ceramic; and the electrical conductor comprises at least one of the following materials: metal; metal alloy; stainless steel 300 series; stainless steel 400 series; titanium; NiFe; NiFeCo alloy; niobium; copper; tungsten; molybdenum; platinum; an alloy of one of metal, stainless steel 300 series, stainless steel 400 series, titanium, NiFe, NiFeCo alloy, niobium, copper, tungsten, molybdenum, and platinum.

14. The electrical feedthrough according to claim 1, wherein the base body and the electrical conductor only comprise non-allergic materials, wherein the base body and the electrical conductor are free of a nickel leaching.

15. A port for electronic devices, the port being one of a charging port and a medical port, the port comprising: an electrical feedthrough, comprising: a base body having a first side and an opposed second side and at least one through-hole extending through the base body from the first side to the second side; an insulating material received in the at least one through-hole, the insulating material having a first surface on the first side of the base body and an opposed second surface on the second side of the base body; and an electrical conductor extending through the insulating material, the electrical conductor having a first diameter at a location of the first surface of the insulating material and a second diameter at a location of the second surface of the insulating material, the first diameter of the electrical conductor being larger than the second diameter of the electrical conductor.

16. The port according to claim 15, wherein the port is configured for being for wearables.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0055] The above-mentioned and other features and advantages of this invention, and the manner of attaining them, will become more apparent and the invention will be better understood by reference to the following description of embodiments of the invention taken in conjunction with the accompanying drawings, wherein:

[0056] FIG. 1 is a top view of an electrical feedthrough including 4 through-holes, wherein an electrical conductor extends through each through-hole,

[0057] FIGS. 2-4 are side views of 3 different electrical feedthroughs including 4 through-holes, wherein an electrical conductor extends through each through-hole;

[0058] FIGS. 5A, 5B, 5C, 5D, and 5E are side views of 5 different electrical conductors;

[0059] FIGS. 6A, 6B, 6C, and 6D are side views of 4 different electrical feedthroughs including 1 through-hole, wherein an electrical conductor extends through the through-hole;

[0060] FIG. 7 shows computer simulation results for the contact pressure on the insulation material for the 4 different electrical feedthroughs of FIGS. 6A-6D;

[0061] FIGS. 8A and 8B are perspective views of 2 different electrical conductors in a through-hole;

[0062] FIGS. 9A, 9B, 10A, 10B, 11A, 11B, 12A, 12B, 13A, 13B, 14A, 14B, 15A, 15B, 16A, and 16B show computer simulation results for the level of plastic deformation of the base body and the contact pressure in the insulation material for the 2 different electrical conductors of FIGS. 8A-8B and corresponding results with different separating wall distances;

[0063] FIGS. 17A and 17B are top views of 2 different electrical feedthroughs including 3 electrical conductors.

[0064] Corresponding reference characters indicate corresponding parts throughout the several views. The exemplifications set out herein illustrate embodiments of the invention, and such exemplifications are not to be construed as limiting the scope of the invention in any manner.

DETAILED DESCRIPTION OF THE INVENTION

[0065] Referring to FIG. 1-5, an electrical feedthrough 10 with a base body 20 may include one or more through-holes 26 in which an insulating material 30 and at least one electrical conductor 40 is received. The electrical conductor may also be referred to as electrical pin.

[0066] For several practical applications, it may be desired to provide feedthroughs 10 with relatively thick electrical conductors 40 in relation to the diameter of the through-hole DTH, to the distance between adjacent through-holes ΔTH and/or to a half-distance diameter DBB=DTH+ΔTH, while at the same time hermeticity, electrical insulation between conductors 40 and/or the base body 20 or other properties of the sealing should satisfy certain quality requirements.

[0067] Multiple approaches may be considered for this purpose. In particular, instead of using electrical conductors 40 with constant diameter DEC1=DEC2 (FIG. 2), conductors 40 with a larger diameter DEC1 on a first side 22 of the base body 20 and a smaller diameter DEC2 on a second side 24 of the base body 20 may be employed (FIG. 3-5).

[0068] For example, the first side 22 of the feedthrough 10 on which the electrical conductor 40 has a larger diameter DEC1 may be facing the exterior of a device, whereas the second side 24 of the feedthrough 10 on which the electrical conductor 40 has a smaller diameter DEC2 may be facing the interior of a device.

[0069] Such asymmetrical pin diameters (for example external and internal) may increase performance and/or optimize desired dimension ratios of the feedthrough 10. On the one hand, a larger pin external diameter DEC1 can provide higher contact area which may be beneficial for a mating contact area. This may be especially helpful in case of tolerances of a mating component, which may be pogo pins. On the other hand, a smaller internal pin diameter DEC2 may allow relatively small flex outlines. The internal pin end may be mated to another component through various ways, such as by soldering.

[0070] According to one embodiment, asymmetrical pin diameters DEC1>DEC2 may be realized with a step design (FIG. 3). In this case, the electrical conductor 40 has a first section 42 with the first diameter DEC1 extending from the first surface 32 of the insulating material 30 into the insulating material 30 and a second section 44 with the second diameter DEC2 extending from the second surface 34 of the insulating material 30 into the insulating material and a vertical step in between these two sections 42, 44.

[0071] In some cases of GTMS, where the insulation material 30 is glass, depending on the dimensions of the components of the feedthrough 10 and processes used, such step design may lead to situations during glass sealing process whereby the glass flow is insufficient to cover the entire cavity. In such cases bubbles or gaps may result at certain locations which creates risks of leakage. Also in some cases of GTMS, the sharp corners of the step pin design, may lead to high stress areas which may be prone to glass cracks which may also lead to risk for leakage.

[0072] However, such problems are only expected under specific conditions and/or dimensions of the components of the feedthrough 10 and can be solved by suitable processes and/or materials, as detailed further below.

[0073] Alternatively or additionally, a tapered pin design may be beneficial (FIG. 4-5). In this case, the electrical conductor 40 may have a first section 42 with the first diameter DEC1 extending from the first surface 32 into the insulating material 30 and a second section 44 with the second diameter DEC2 extending from the second surface 34 into the insulating material as well as a tapered section 46 between these two sections 42, 44 (FIG. 4, 5a, 5b).

[0074] However, the electrical conductor 40 may also be designed to have a tapered section 46 with the first diameter DEC1 followed by a second section 44 with the second diameter DEC2 (FIG. 5c). Conversely, the electrical conductor 40 may also be designed to have a first section 42 with the first diameter DEC1 followed by a tapered section 46 including the second diameter DEC2 (FIG. 5d). Furthermore, it is also possible that the electrical conductor 40 is tapering from the first diameter DEC1 at the first surface 32 up to the second diameter DEC2 at the second surface 34 of the insulating material 30 (FIG. 5e). Note that in FIGS. 5d and 5e the second diameter DEC2 may be at any position within the tapering section 46 or at its end, depending on where the second surface 34 of the insulating material 30 is located.

[0075] In addition, to allow for a stronger mechanical interlock between the insulation material 30 (e.g. glass) and the conductor 40, one or more grooves 48 can be implemented on the conductor 40 so that insulation material 30 can flow into the conductor to create e.g. a Velcro interlock.

[0076] Electrical conductors 40 may be produced for example by CNC, MIM and/or forging, in particular in the case of tapered designs.

[0077] Generally, asymmetric pin designs have shown to increase GTMS performance, for example mechanical robustness and/or hermeticity, in particular for the soldering area in glass-to-metal seal systems. Tapered pin designs may improve insulation material flow (lesser constriction areas) in production, and, thus, may reduce the risk of bubbles, cracks, and/or lower the stress due to less sharp corners, in particular for glass insulation material (GTMS).

[0078] Referring to FIGS. 6-16, it is illustrated that asymmetric conductor designs (DEC1>DEC2), and in particular tapering designs, improve contact pressure conditions on the components of the feedthrough leading to better hermeticity and/or mechanical robustness, e.g.

[0079] for a soldering process. Contact pressure has a direct relation to mechanical robustness and seal integrity of the feedthrough.

[0080] Four variants of pin/glass systems were constructed and analyzed to illustrate relationships between pin thickness, glass thickness and the robustness of the glass-to-metal seal system: A first variant refers to a glass/pin system with typical design guidelines, i.e. glass with nominal gap (FIG. 6a). A second variant refers to a system with increased pin diameter, i.e. a thick pin and narrow glass gap (FIG. 6b). A third variant refers to a system with decreased pin diameter with a narrow glass gap, i.e. a thin pin and narrow glass gap (FIG. 6c). A fourth variant refers to an asymmetric pin design having a larger landing zone on the external side for contact and thinner internal diameter for smaller soldering outline, i.e. a “nailhead” pin design (FIG. 6d).

[0081] For these 4 variants, computer simulation results of the contact pressure on the insulation material (glass) are illustrated in FIG. 7. Aforementioned first variant (glass with nominal gap) is curve 100, second variant (thick pin and narrow glass gap) is curve 102, third variant (thin pin and narrow glass gap) is curve 103, and fourth variant (nailhead design) is curve 101. The thickness L of the feedthrough (see FIG. 4) is 2 and x-axis value of 0 corresponds to the first side 22 of the base body (e.g. external area) and x-axis value of 2 corresponds to the second side 24 (e.g. internal area with protrusion for soldering).

[0082] It is found that for the first variant 100, the insulation material has superior contact strain at its surfaces (x=0, x=2) as compared to the second and third variants 102, 103, where the insulation material is under negative contact pressure (i.e. contact tension). However, for the fourth variant 101 the insulating material has superior contact strain as compared to the second and third variants 102, 103. In particular, on the second surface (x=2), the insulation material is under negative contact pressure CP2 with an absolute value being lower as compared to the second and third variants 102, 103, or is under a positive contact pressure CP2.

[0083] Such contact pressure, in particular positive contact pressure, on the glass indicates a more robust glass sealing system which in turns help in the mechanical robustness of the pins on the second side (e.g. soldering side). This may be of particular advantage as pins at the soldering side are subjected to heat mechanical stresses during the soldering process.

[0084] In the nailhead design, the pressure does not get build up over the nail head pin system. Moreover, in the nail head pin system, the insulating material may be under highest positive contact pressure CP3 with an absolute value which is lower than 45 MPa, or lower than 35 MPa.

[0085] To support the aforementioned findings, FIGS. 8-16 show further computer simulation results for a nailhead pin design (a) and a straight pin design (b) for the level of plastic deformation of the base body (FIG. 9, 11, 13, 15) and the contact pressure in the insulation material (FIG. 10, 12, 14, 16) for different separating wall distances: 2.21 mm; 2.11 mm; 2.01 mm; and 1.81 mm.

[0086] Referring to FIG. 17 an electrical feedthrough including multiple electrical conductors 40 may have an individual through-hole 26 for each conductor 40 (FIG. 17a) or may have multiple electrical conductors 40 extending through the same through-hole 26 (FIG. 17b).

[0087] In both cases, aforementioned pin designs enable systems with optimized sealing properties while at the same time distances ΔEC between two electrical conductors and/or distances ΔECBB between an electrical conductor and the base body may be decreased, in particular to allow for high density pin configurations (typically a lower pitch distance corresponds to a higher density of pins for a given area).

[0088] Additionally or alternatively, providing feedthroughs having decreased ΔEC, decreased ΔECBB and/or allow for a desired electrical conductor diameter in relation to DTH, ΔTH and/or DBB (FIG. 1), while at the same time sealing properties meet high quality standards, can be achieved by material selection and/or selection of thermal expansion coefficients (CTE).

[0089] For example, the selection of metal housing may have an impact on the pin-to-pin (pitch) spacing. To achieve high levels of corrosion resistance and reliability performance, metals like stainless steel or Ti can be utilized. For metals with high CTE, e.g. 316L, pitch spacing may be higher compared to metals like stainless steel 400 series and Ti. For a low weight, high reliability, high density glass-to-metal seal and/or biocompatibility, Ti may be chosen as material for the base body and/or pins. The base body and/or the pins may be optionally Non-Ni materials or free of nickel leaching.

[0090] In one exemplary embodiment, the base body may include SS316L and DBB/DTH may be 1.6. In another exemplary embodiment the base body may include SS400 series/Ti and DBB/DTH may be 1.3.

[0091] In one exemplary embodiment, the base body may include SS316L and the conductor may include SS316L. In another exemplary embodiment the base body may include SS400 series/Ti and the conductor may include SS400 series.

[0092] While this invention has been described with respect to at least one embodiment, the present invention can be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims.