阅读说明：本技术 玻璃-金属馈通件 (Glass-metal feed-through ) 是由 R·海特乐 于 2019-07-22 设计创作，主要内容包括：本发明涉及一种玻璃-金属馈通件,其由外导体、玻璃材料和内导体构成,其中内导体具有膨胀系数α<Sub>内</Sub>,玻璃具有膨胀系数α<Sub>玻璃</Sub>并且外导体具有膨胀系数α<Sub>外</Sub>,其特征在于,内导体的膨胀系数α<Sub>内</Sub>大于玻璃的膨胀系数α<Sub>玻璃</Sub>,并且在20℃直至玻璃转变温度的温度范围中外导体的膨胀系数α<Sub>外</Sub>比玻璃的膨胀系数α<Sub>玻璃</Sub>高至少2ppm/K、优选至少4ppm/K。(The present invention relates to kinds of glass-goldA feedthrough comprising an outer conductor, a glass material, and an inner conductor, wherein the inner conductor has a coefficient of expansion of α Inner part The glass has an expansion coefficient of α Glass And the outer conductor has a coefficient of expansion α Outer cover Characterized by an expansion coefficient α of the inner conductor Inner part Coefficient of expansion greater than that of glass α Glass And an expansion coefficient α of the outer conductor in a temperature range of 20 ℃ up to the glass transition temperature Outer cover Coefficient of expansion α of glass Glass At least 2ppm/K, preferably at least 4 ppm/K.)

A glass-to-metal feedthrough of comprising an outer conductor, a glass material, and an inner conductor, wherein the inner conductor has a coefficient of expansion of α_{Inner part}The glass has an expansion coefficient of α_GlassAnd the outer conductor has a coefficient of expansion α_{Outer cover}The method is characterized in that the method comprises the following steps of,

coefficient of expansion α of the inner conductor_{Inner part}Greater than the coefficient of expansion α of the glass_GlassAnd an expansion coefficient α of the outer conductor in a temperature range of 20 ℃ up to the glass transition temperature_{Outer cover}Coefficient of expansion α with the glass_GlassIs at least 2ppm/K, preferably at least 4ppm/K, and the outer conductor has an expansion coefficient α_{Outer cover}Greater than the coefficient of expansion α of the glass_Glass。

2. Glass according to claim 1Glass-metal feedthrough characterized in that the inner conductor has a coefficient of expansion α_{Inner part}Coefficient of expansion α of the glass_Glass1.1 times larger, preferably twice as large, especially 4 · α_GlassTo 1.5. α_GlassIn the range of (1).

3. The glass-metal feed-through of any of claims 1-2, wherein the outer conductor is made of steel (high quality steel) that is preferably nickel-free, rust-free, chemical-resistant.

4. Glass-metal feed-through according to claim 3, characterized in that the outer conductor is made of a stainless, chemically resistant steel, in particular austenitic high-quality steel, in particular AISI 316L.

5. The glass-metal feed-through of any of claims 1-4,

the outer conductor is made of a nickel-free, rust-free, chemical-resistant steel, in particular a ferritic high-grade steel, in particular AISI 430.

6. The glass-metal feed-through of any of of claims 1-5,

the inner conductor is formed from of the following material:

nickel-free ferritic stainless steel, in particular non-hardenable ferritic stainless steel, preferably with a high chromium content, in particular between 10.5 and 20%, preferably between 15 and 17%, preferably AISI430,

-molybdenum

-tungsten

-platinum (II)

-niobium

-titanium

-platinum/iridium.

7. The glass-metal feed-through of any of of claims 1-6,

the expansion coefficient of the inner conductor and the expansion coefficient of the outer conductor are selected such that a joining pressure of at least 30Mpa, preferably at least 50Mpa, in particular at least 100Mpa, is formed on the inner conductor.

8. Use of a glass-metal feedthrough according to any of claims 1-7 in an implantable medical device or apparatus.

Element of kinds, which can be introduced into or attached to a human or animal body or living biological cells containing cell cultures, having a glass-metal feed-through according to any of claims 1 to 7, wherein the outer conductor and the inner conductor consist of a metal with a reduced susceptibility to allergy, at least in a surface region which is in contact with the human or animal body in the operating state.

10. Element according to claim 9, characterized in that the metal of the outer conductor and the metal of the inner conductor in contact with the human or animal body or cell culture are free of nickel and/or chromium deposits.

11. Element according to at least of claims 9 to 10, characterized in that the metal of the outer conductor and the metal of the inner conductor at least in the surface region which is in contact with the human or animal body or the biological cells of the cell culture in the operating state consist of nickel-free steel and/or chromium-free steel.

12. Element according to at least of claims 9 to 11, characterized in that the metal of the inner conductor at least in the surface region which is in contact with the biological cells of the human or animal body or cell culture in the operating state is selected from the group:

ferritic stainless steel (AISI 4xx)

-platinum (II)

-platinum/iridium

-niobium

-titanium

-molybdenum

-tungsten

And compositions thereof.

13. Element according to claim 12, characterized in that the metal of the outer conductor at least in the surface region which is in contact with the biological cells of the human or animal body or cell culture in the operating state is selected from the group:

austenitic high-quality steels AISI 3xxx, in particular

-AISI 316 L

Ferritic stainless steels AISI 4xxx, in particular

-AISI 430

-AISI 630

And compositions thereof.

Technical Field

The invention relates to glass-metal feedthroughs, which are composed of an outer conductor, a glass material and an inner conductor, and to the use thereof in medical devices, in particular implantable medical devices and apparatuses, and to devices having such glass-metal feedthroughs.

Background

A very specific glass-metal feedthrough is one in which the feedthrough itself or the feedthrough part of the feedthrough is in contact with the human body, in which all components used have a high corrosion resistance and good durability.

Fe-Ni, Fe-Ni-Co, Fe-Ni-Cr alloys are mainly used as materials for conductors of feed-throughs in glass-metal feed-throughs. The advantage of these materials is that their thermal expansion matches the molten glass very well. But all of these materials have a significant Ni content in the base material. Furthermore, it has a nickel coating, protecting the material from corrosion, which in turn releases an undesirable amount of nickel.

In order to prevent Ni release, it is provided in the prior art that the feedthrough conductor or the inner conductor is provided with a sufficiently thick gold coating in order to reduce nickel penetration. This has the disadvantage, however, that it only does not prevent the Ni bleeding sufficiently, or that a very thick gold coating with a thickness of more than 2.5 μm is required to achieve this effect.

Instead of the solution for coated conductors, DE 19842943 a1 proposes, as the closest prior art, the use of tantalum as the inner conductor or alternatively the use of nickel-free, carbon-coated,Stainless ferritic stainless steel, such as steel according to US standard AISI 446, which is a stainless, heat-resistant ferritic chromium steel with aluminium additions. ferritic stainless steel AISI 446 has an expansion coefficient only slightly higher than that of conventional glass, there is therefore a risk that the inner conductor shrinks more strongly on cooling than glass and the interface with glass breaks open.a further disadvantage of DE 19842943 a1 is that the choice of Ni-free material is limited, since only the expansion coefficient of the inner conductor α is limited_{Inner part}Coefficient of expansion α less than that of glass_GlassProviding sufficient tightness of the feed-through.

glass compositions are known from US 3,770,568A, which can be used for hermetically sealed tantalum electrolytic capacitors and include an effective chromium content in the glass composition.

Disclosure of Invention

It is therefore an object of the present invention to provide glass-to-metal feedthroughs, which allow a wider choice of the material of the inner conductor and provide a sealed feedthrough.

In particular, it is possible for the inner conductor to have no nickel released on its contact with the human body, and also to have sufficient solderability on its side.

This object is achieved by a glass-metal feed-through having the integral features of claim 1. Advantageous embodiments of the invention are the subject matter of the dependent claims.

The glass-metal feed-through according to the invention is characterized in that the coefficient of expansion of the inner conductor is α_{Inner part}Coefficient of expansion greater than that of glass α_GlassAnd an expansion coefficient α of the outer conductor in a temperature range of 20 ℃ up to the glass transition temperature_{Outer cover}And coefficient of expansion α of glass_GlassThe difference between them is at least 2ppm/K, preferably at least 4ppm/K, and the coefficient of expansion of the outer conductor is α_{Outer cover}Coefficient of expansion greater than that of glass α_Glass。

This is achieved by pretensioning the outer conductor against the glass with a pressure, which also exerts a positive pressure (bonding pressure) on the interface of the glass and the inner conductor. The advantage results therefrom that the pressure reliably and sealingly holds the connection. Furthermore, a small structural height of the glass-metal feed-through is achieved, and this can be used in different fields of application, for example bracelets which can be used for monitoring devices for patients or in the leisure sector.

The limitation of the large expansion of the pin as inner conductor with respect to the glass and the expansion of the outer conductor with respect to the glass are at least 2ppm/K greater, which is particularly effective in the case of a pin of a material which expands very much, with an expansion higher than 10 ppm/K. There is little good molten glass in this range.

Surprisingly, the present inventors have found that for example ferritic high-grade steels with a high chromium content of between 10.5% and 20%, preferably high-grade steels with a chromium content of from 15 to 17%, such as ferritic high-grade steel AISI430, can be used instead of ferritic high-grade steels also other materials, such as molybdenum, tungsten or platinum, can be used, which also have a low susceptibility_{Inner part}＞α_GlassWherein α_{Inner part}Is the coefficient of expansion of the inner conductor and α_GlassIs the coefficient of expansion of the glass.

However, the use of these steels is problematic in that they are 11.6 to 11.5.10^-6Thermal expansion coefficient of α/K_{Inner part}Is obviously higher than 10.6 to 6.1.10^-6Coefficient of expansion α of glass in the/K range_GlassThe inventors have surprisingly found that α despite the conductor_{Inner part}Larger, it is higher than α_GlassAs opposed to the thermal expansion of the inner conductor in the glass-to-metal feed-through as specified in the prior art, which is not allowed to exceed that of the glass used in order to provide sufficient hermeticity, but at α_{Inner part}Greater than α_GlassAs further studies have shown that, when the joining pressure is only positive, it is not sufficient for the sealing properties, but the joining pressure must be greater than 30Mpa, preferably greater than 50Mpa, in particular greater than 100Mpa, in order to achieve a reliable embedding.

At α_{Inner part}Less than α_GlassIn the case of applying a sufficient pressure pretension to the glass by the outer conductorIf the joining pressure is clearly positive, i.e. greater than 30Mpa or greater than 50Mpa, in particular greater than 100Mpa, the transition between glass and metal, i.e. from glass to inner conductor, remains closed, and although α does not appear to be present_{Inner part}Less than α_GlassThe bonding pressure is a face pressure, which refers to how much force per unit area the th body is pressed against the second body.

Coefficient of expansion α of the outer conductor in order to apply the required bonding pressure_{Outer cover}And glass, wherein the coefficient of expansion is greater than α, and preferably at least 4ppm/K_GlassIn a particularly preferred embodiment, α of the inner conductor_{Inner part}Is selected such that the coefficient of expansion of the inner conductor α_{Inner part}Coefficient of expansion α of glass_GlassGreater than 1.1 times in a particularly preferred embodiment, α_{Inner part}At 1.1. α_GlassTo 2.α_GlassIn the range of (1). In order to apply the required pressure of the outer conductor to the glass material and to ensure the sealing, it is provided that the outer conductor is composed of nickel-free, stainless, chemically resistant steel (high-quality steel). The outer conductor has a coefficient of expansion greater than that of the glass to provide the required bonding pressure.

It is particularly preferred that the outer conductor is an austenitic high-quality steel, preferably high-quality steel 316L, characterized by good weldability and high expansion coefficient.

Apart from nickel-free ferritic high-quality steels, in particular non-hardenable ferritic high-quality steels with a high chromium content, have a coefficient of expansion of α_{Inner part}Larger than the coefficient of expansion of the glass material, it is also conceivable to use molybdenum or tungsten or platinum for the inner conductor. Preferably, the coefficient of expansion is selected such that the bonding pressure on the inner conductor is at least 30Mpa, preferably at least 50Mpa, in particular at least 100 Mpa.

In addition to the feed-through, the invention also provides the use of a glass-metal feed-through according to the invention in an implantable medical device or arrangement, and also an element which is introducible or attachable to a human or animal body or living biological cells containing cell cultures, having a glass-metal feed-through according to the invention, wherein the outer conductor and the inner conductor are composed of a metal having a reduced susceptibility to allergy at least in a surface region thereof which is in contact with the human or animal body in the operating state. Preferably, both the outer conductor and the inner conductor are also composed of these metals.

The metal of the outer conductor and of the inner conductor may be in contact with the human or animal body or cell culture and is characterized by the absence of nickel and/or chromium deposits.

Preferably, the metal of the outer conductor and the metal of the inner conductor consist at least in their surface regions of nickel-free steel and/or chromium-free steel, which surface regions are in contact with biological cells of the human or animal body or of the cell culture in the operating state.

Particularly suitable as metal of the inner conductor, at least in the surface region, are metals selected from the following group: ferritic stainless steel, such as platinum, platinum/iridium, niobium, titanium, molybdenum, tungsten and combinations thereof, which in the operating state is in contact with biological cells of the human or animal body or cell cultures. Ferritic quality steels include the AISI4xx family, such as AISI 430.

The metal of the outer conductor is preferably selected from the following group at least in the surface region:

AISI 316L

AISI 430

AISI 630 and combinations thereof, which surface region is in contact with biological cells of a human or animal body or cell culture in an operational state. Other materials of the outer conductor may be selected from the group: austenitic stainless steels AISI 3xx or ferritic stainless steels AISI4 xx.

Drawings

The invention is described in detail below times with reference to the accompanying drawings, in which:

FIG. 1 shows a schematic diagram of an embodiment of the present invention;

fig. 2a-2b show the distribution of the bonding pressure of the conductor and the glass.

Detailed Description

Fig. 1 shows a schematic representation of a section through an embodiment of the invention. In the glass-metal feed-through shown in fig. 1 through the housing 1, the feed-through 3 is inserted into an opening 5 of the housing 1, which may preferably be made of aluminum. The feedthrough 3 comprises a feedthrough conductor or inner conductor 7 encased in an outer conductor 9. The outer conductor 9 may also be referred to as a matrix and is preferably composed of austenitic high-quality steel having a high coefficient of thermal expansion. The outer conductor can also be referred to as a base body and is connected to the housing, preferably by welding. The inner conductor or feedthrough conductor 7 is embedded centrally in the outer conductor. This is achieved in that the inner conductor 7 completely fills the space inside the outer conductor 9 in the insulating glass body 11. The glass in which the inner conductor is melted is preferably biocompatible glass.

The diameter d of the feedthrough conductor 7 and the so-called bore diameter of the opening 5 are likewise shown in fig. 1.

According to the invention, the glass has an expansion coefficient of α_GlassThe inner conductor has a coefficient of expansion α_{Inner part and inner part}And the outer conductor has a coefficient of expansion α_{Outer cover}The material is selected such that the inner conductor has a coefficient of expansion α_{Inner part}Coefficient of expansion greater than that of glass α_GlassThe difference between the expansion coefficient of the outer conductor and the expansion coefficient of the glass is at least 2ppm/K, preferably at least 4ppm/K the expansion coefficient of the outer conductor in the temperature range from 20 ℃ up to the glass transition temperature α_{Outer cover}Coefficient of expansion greater than that of glass α_Glass. The joining pressure provided at the inner conductor is thus at least 30Mpa, preferably at least 50Mpa, in particular at least 100 Mpa.

Coefficient of expansion α of inner conductor as required by the invention_{Inner part}Coefficient of expansion greater than that of glass α_GlassFig. 2a shows a bonding pressure dependent on D/D according to the prior art, wherein kovar, having α, is used as the material of the feedthrough conductorThe value is 7.3 to 6.6.10^-61/K, slightly higher than coefficient of expansion α_GlassAnd are not included in the present invention. Where D denotes the diameter of the conductor and D denotes the diameter of the opening 5. D/D gives the ratio between the conductor diameter D and the hole diameter D. It is generally applicable that a small D/D value characterizes a large gap between the conductor and the opening, and a large D/D value characterizes a small gap between the conductor and the opening.

Although the feedthrough according to fig. 2a is hermetically sealed, it has the disadvantage that kovar has a high nickel content, so that nickel can be released from the feedthrough conductor.

It is therefore provided according to the invention that the kovar feedthrough conductor is replaced by a material that does not release nickel it has surprisingly been found that a suitable material for this is a ferritic Ni-free stainless steel, in particular AISI430, but a disadvantage of a Ni-free ferritic stainless steel, such as AISI430, is α_{Inner part}Is 11.5 to 10^-6K^-1And thus significantly higher than the coefficient of expansion α of the glass material_GlassCoefficient of expansion α of the added glass_GlassAt 6.1 to 10^-6K^-1To 10.6.10^-6K^-1In the range of (1).

In order to achieve a pressure-tight embedding in this case, a sufficiently high joining pressure must be built up, which is applied via the outer conductor.

The D/D-dependent joining pressure for such a feedthrough is shown in fig. 2 b.

As can be seen from fig. 2b, α is provided especially in the outer conductor for the material using AISI430 as feed-through member_{Outer cover}Is 18.3 to 10^-6With a construction of austenitic high-quality steel/K, a sufficiently high joining pressure is achieved. This configuration has a sufficiently high engagement pressure to ensure sealability. The bonding pressures for this combination of materials are indicated by reference numerals 100 and 200. The joining pressure increases with larger D/D and small clearance to values above 150 Mpa.

Curves 300 and 400 depict the junction pressure of an AISI430 feedthrough conductor, where the outer conductor is AISI430 or AISI 630, and the glass has a 10.6·10^-6The coefficient of expansion of/K, and thus in the range of coefficients of expansion of the outer conductor and the feedthrough conductor. The required joining pressure cannot be built up. Typically such material combinations exhibit low bonding pressures. Curves 300 and 400 run smoothly and are affected little by the diameter ratio.

The materials of the different curves in the diagram "joining pressure with D/D" according to fig. 2b are obtained from the following table:

table form

The material combination of the curves 100, 200 has a particularly high joining pressure, so that a tight seal is provided for the feedthrough.

The glass-metal feedthrough may be used in an implantable medical device or apparatus. The glass-metal feed-through can be produced cost-effectively and is characterized by a very low Ni bleed-out. Furthermore, the glass-metal feed-through has a tight seal due to the high joining pressure, i.e. a helium leakage of less than 1 · 10^-8mbar/sec。