Metal fixing material feed-through that is less prone to errors

Abstract

A metal fastening material feedthrough for an igniter of an airbag and / or a seat belt pretensioner, the metal fastening material feedthrough having at least one metal pin fused in a glass or glass ceramic fastening material into a through-hole of a base, the metal being present in a post-heated state, the metal fastening material feedthrough having an interface between the fastening material and the metal pin and another interface between the fastening material and the inner surface of the through-hole of the base, wherein the at least one metal pin comprises, at least in its core region, a special steel, preferably a chromium-containing special steel, which has a predetermined thermal expansion coefficient α 金属ピン 1. A metal fastener feedthrough comprising:

Description

Technical Field

[0001] The present invention relates in particular to a metal fixing material feed-through for a device that can be exposed to high pressure, preferably for a personal protection device such as an igniter for an airbag or a seat belt pretensioner, having at least one metal pin fused into a fixing material, preferably a glass material or a glass ceramic material.

Background Art

[0002] Metal fixing material feed-throughs are known in various configurations according to the prior art.

[0003] Metal fixing material feed-throughs include a vacuum-tight fusion of a fixing material, in particular glass, glass ceramic, or plastic with metal. In this case, the metal functions as an electrical conductor.

[0004] In this case, as representative examples, reference is made to U.S. Patent No. 5,345,872 or U.S. Patent No. 3,274,937. Feed-throughs of such a type are widely used in electronics and electronic technology. The materials used for the fusion, in particular glass, function as insulators in this case. A typical metal fixing material feed-through is configured such that a metallic inner conductor is mounted in a glass material, in which case the glass material is fused into a so-called matrix formed from ring-shaped or plate-shaped elements within an outer metallic part.

[0005] Suitable examples of the use of a metal fixing material feed-through of such a type include, for example, an ignition device. Such an ignition device is used, inter alia, for an airbag or a seatbelt pretensioner of a motor vehicle. In this case, the metal fixing material feed-through is a component of the ignition device. The entire ignition device includes, in addition to the metal fixing material feed-through, an ignition bridge, an explosive, and a metal cover that closely surrounds the ignition mechanism. The feed-through can guide one or two or three or more metal pins. In a particularly preferred embodiment with metallic pins, the casing is on the ground, and in a suitable two-pole configuration, the ground is located on one of the pins.

[0006] According to US Patent Application Publication No. 2006 / 0222881, US Patent Application Publication No. 2004 / 0216631, European Patent Application Publication No. 1455160, US Patent Application Publication No. 2007 / 0187934, and US Patent No. 1813906, a metal fixing material feed-through for an igniter of an airbag or a seatbelt pretensioner is known, and this metal fixing material feed-through is characterized in that a through-hole for a metal pin is punched out from a substrate. According to US Patent Application Publication No. 2007 / 0187934, when manufacturing the substrate, an opening that penetrates the entire thickness of the substrate D is punched out from a strip material having a thickness in the range of 1 mm to 5 mm, preferably 1.5 mm to 3.5 mm, particularly 1.8 mm to 3.0 mm, and extremely particularly preferably 2.0 mm to 2.6 mm, by a punching process.

[0007] The substrate is generally also called a header.

[0008] In the feedthrough known from International Publication No. WO 2012 / 110242, a substrate with a conductor hermetically sealed therein is hermetically attached into a casing by welding, brazing, press fitting, crimping, or shrink fitting. The casing part and / or the substrate, preferably a substantially ring-shaped substrate, in International Publication No. WO 2012 / 110242, includes, as materials, metals, especially light metals such as titanium, titanium alloys, magnesium, magnesium alloys, aluminum alloys, aluminum, AlSiC, but also includes steel, stainless steel, or special steel.

[0009] The metal pins in the fixing material are inserted into through holes punched in the substrate over the entire thickness D of the substrate within the above range, and are especially hermetically sealed. The hermetic sealing is first performed by fusing the metal pins into a fixing material, for example a glass plug. Then, the metal pins together with the glass material are inserted into the through holes, and the metal pins, the glass material, and the substrate are heated, and after cooling, the metal, preferably the metal of the substrate, is made to shrink on the fixing material, for example the glass plug.

[0010] Since the coefficient of thermal expansion of the substrate is larger than that of the fixing material, after cooling, a compressive glass-metal seal, especially a particularly airtight compressive glass-metal seal, is formed.

[0011] By "airtight" in the present application, it should be understood that the helium leak is less than 1×10 -8 mbar l / second.

[0012] In order to produce a continuous compression-type glass-metal seal that remains continuously sealed in the operating state even after cooling and subsequent thermal cycles, the prior art assumes that, particularly in the igniters of personal protection devices such as airbags and / or seat belt pretensioners, the coefficients of thermal expansion of the materials involved must have a predetermined ratio to each other. In a compression-type glass-metal seal, since the base body should be shrink-fitted onto a glass material, also called a glass body, the coefficient of thermal expansion of the base body must be greater than that of the glass material. When cooled, the glass-sealed metal pin must not become detached from the glass material, so in known means, the metal pin also has a coefficient of thermal expansion smaller than that of the glass material. Therefore, when special steel is used as the material of the base body in the igniter of a personal protection device, usually, a metal pin made of nickel iron or a nickel iron alloy is sealed into the glass material.

[0013] Furthermore, in a feed-through with two or more pins according to US Patent Application Publication No. 2007 / 0187934, the through-holes are arranged eccentrically.

[0014] The punching of the base body from a metal sheet material according to US Patent Application Publication No. 2007 / 0187934 has drawbacks. One drawback is that when punching the base body from a strip material, for example, a metal sheet, a certain proportion of material waste is generated.

[0015] According to German Patent Application Publication No. 102010045624, it has been proposed to produce the base body from wire material by a cold forming process and to provide an open area in the base body, whereby through-holes can also be punched from the base body produced by the cold forming process.

[0016] German Patent Application Publication No. 102006056077 shows a pyrotechnic protection device, particularly for an airbag or a seat belt pretensioner, which has a through-hole provided in the base body, and this through-hole is provided in the base body by punching.

[0017] Further documents on metal feed-throughs are, for example, EP 1 491 848 A1, EP 1 455 160 A1, EP 1 813 906 A1, EP 2 431 703 A1 or DE 10 2006 004 036 A1.

[0018] In particular, in metal feed-throughs with two metal pins, the through-holes for attaching at least one metal pin are often arranged eccentrically. Eccentric through-holes may have disadvantages in efficient mass production.

[0019] From all the above applications regarding metal feed-throughs, in particular after the metal pins have been glass-sealed in the glass material, reliable post-processing, for example a pin material that enables assembly, is not known. The pin material disclosed in WO 2012 / 110245, in particular NiFe, has a tendency to bend, and in extreme cases break, when inserted, for example, into a connector during efficient mass production in an automated manufacturing apparatus and / or during further processing of the metal feed-through for an igniter and / or assembly of the final product, which may result in, for example, unwanted defective products. SUMMARY OF THE INVENTION PROBLEM TO BE SOLVED BY THE INVENTION

[0020] Accordingly, an object of the present invention is to provide a metal feed-through with a conductor that avoids the disadvantages of the prior art, can be manufactured with a lower defect rate in efficient mass production, and / or is excellent in that it can be assembled more reliably, for example, when inserting the final product onto or into a connector. MEANS FOR SOLVING THE PROBLEM

[0021] According to the present invention, this problem is solved by a metal fixing material feed-through having at least one metal pin, wherein at least one metal pin is made of special steel based on the standard EN10020, at least in its core region, and this metal pin is such that the special steel has a maximum elastic deflection of less than 0.13 mm, preferably less than 0.15 mm, preferably less than 0.18 mm, particularly less than 0.20 mm, very particularly preferably less than 0.21 mm, when the metal pin is converted to standard dimensions having a metal pin diameter of 1.00 ± 0.03 mm and a metal pin length of 11.68 ± 0.2 mm. Very preferably, the maximum elastic deflection is in the range of 0.01 to 0.26 mm.

[0022] In the concept of the present invention, elastic deflection means the deflection of the metal pin such that when the mechanical load is removed, the metal pin returns at least approximately to its original shape. In this case, at least approximately no plastic deformation occurs, or in other words, the material of the metal pin is in the range of elastic deformation within the above load range.

[0023] The metal pin length is measured as the protrusion of the metal pin from the lower surface of the glass seal, and thus the length of the glass seal and / or the thickness of the header are irrelevant.

[0024] According to the present invention, since the metal pin is fused into the through-hole of the substrate within a glass or glass-ceramic material, the metal pin is usually heated to a temperature of 600 °C or higher, particularly 650 °C or higher, during glass sealing. Thereafter, the metal pin is cooled again. As a result, the special steel of the metal pin exists in the cooled state after heating after glass sealing, and this is generally in an annealed state, or in English, called "annealed". The material properties of the annealed special steel are very different from those in the unprocessed state, i.e., the non-annealed state.

[0025] The metal pin may exist as a solid material or as a coated solid material. In the case of a coated metal pin, the core region of the metal pin is referred to as the solid material, that is, a special steel material surrounded by the coating.

[0026] The present invention has the advantage that the special steel pin is excellent in terms of slight flexibility, especially in the annealed state. This means that a greater mechanical load is required to plastically deform the special steel pin than in the case of the nickel-iron pins conventionally used. Or, in other words, when a mechanical load below plastic deformation is applied, the special steel pin remains elastically deformable. This reduces the possibility of deformation of the special steel pin in the production line, so that the manufacturing process is particularly improved. Similarly, in post-processing such as coating or end polishing, for example, more accurate positioning of tools can be performed. It is also easier to insert a metal pin that is not bent, that is, does not deviate from the target dimensions, into a connector or the like.

[0027] It is particularly preferred if the special steel is selected such that the metal pin exhibits a displacement of at most 0.21 mm, that is, the displacement is less than 0.21 mm, during a standard load test in the range of 3 N to 4 N. In the case of such a slight displacement, only elastic bending or elastic deformation of the metal pin occurs, so that the metal pin is returned to its starting state.

[0028] For this purpose, the standard load test is configured to apply the above mechanical load perpendicular to the pin axis to a metal pin having a dimension of 1.00 ± 0.03 mm and a metal pin length of 11.68 ± 0.02 mm, and to measure the displacement up to the limit value W max reached, in particular the limit of elastic bending. If the metal pin has other dimensions, a corresponding metal pin with the dimensions of the standard load test must be manufactured or the displacement must be calculated accordingly.

[0029] It is particularly preferred if the mechanical load of at least one metal pin according to the invention at 0.25% (strain) exceeds 450 MPa, preferably exceeds 480 MPa, or exceeds 500 MPa, and particularly preferably corresponds to a stress in the range of 450 MPa to 700 MPa. When the stress is high, the flexibility is low, that is, the boundary of plastic deformation is also high. However, materials with high stress are difficult to post-process, especially grinding is more difficult. Therefore, these ranges are particularly preferred. These ranges are higher for quenched metal pins made of special steel than for quenched metal pins made of nickel iron as known in the prior art.

[0030] Surprisingly, when using special steel as the pin material, it was confirmed that the pulling-out force of the metal pin from the glass material of the through-hole is higher than 250 N, particularly in the range of 250 N to 400 N, and preferably in the range of 300 N to 380 N. This is presumably because the glass-sealed and thus quenched special steel metal pin is hard enough to withstand the pressure of the compression-type glass-metal seal well. In other words, when the substrate shrinks on the glass body in the through-hole during cooling as described above, the pressure is applied to the metal pin through the glass body. If the metal pin is soft, it may yield to this pressure, and the clamping action in the glass body may be weaker than in the case of a harder metal pin. In this case, the clamping action is an important aspect regarding the pulling-out force.

[0031] In a preferred embodiment, the special steel metal pin is glass-sealed into the substrate, and this substrate may also be made of metal, particularly steel, stainless steel, special steel, titanium, titanium alloy, magnesium, magnesium alloy, aluminum alloy, aluminum, or AlSiC.

[0032] Particularly preferably, as the material of the substrate, the same material class as that for the material of the metal pins, particularly the metal pins disposed within the fixing material, is used, that is, special steel metal pins and a special steel substrate, or titanium metal pins and a titanium or titanium alloy substrate, or vice versa, etc. The inventors recognize that by selecting the same material class, the possible electrochemical corrosion can be suppressed, which can be particularly suitable for the production process during cleaning and / or electroplating, and can also contribute to the long service life of the final product, such as an igniter.

[0033] It is particularly preferred if the special steel of at least one metal pin (5) is an alloy special steel based on the standard of EN10020, and particularly preferably a chromium-containing special steel.

[0034] Preferably, the special steel is - ferritic special steel, - precipitation hardening special steel, selected from the group of.

[0035] In some cases, martensitic special steel is also considered.

[0036] Since the special steel does not have the above-mentioned ratio of the coefficient of thermal expansion, it is surprising that a continuously stable feedthrough can be obtained by the glass-sealed metal pins made of special steel. That is, usually, the coefficient of thermal expansion of special steel is greater than that of the fixing material used for glass sealing, particularly the coefficient of thermal expansion of the glass material and / or the glass-ceramic material. The fact that a removal force even greater than the removal force by nickel-iron pins corresponding to this ratio can be achieved is the merit of the inventors and was not foreseen beforehand.

[0037] In this case, there is also a particularly preferred range. That is, the coefficient of thermal expansion α 金属ピン or CTE(P) of the special steel at a temperature of 650 °C is 9.0×10 -6 / K to 15.0×10 -6 / K, preferably 11.0×10-6 / K~14.0×10 -6 / K, preferably 11.5×10 -6 / K~14.0×10 -6 / K, or 11.0×10 -6 / K~13.5×10 -6 / K, particularly preferably 11.5×10 -6 / K~12.5×10 -6 / K, it is preferable if it is selected to be in the range.

[0038] In a preferred embodiment, the glass or glass-ceramic fixing material has a coefficient of thermal expansion α in the range of 4×10 -6 1 / K~10.6×10 -6 1 / K at a temperature up to the Tg of this fixing material, particularly of the glass material and / or glass-ceramic material. ガラス Preferably, this state of thermal expansion is combined, in particular, with the above state of thermal expansion of special steel.

[0039] If the substrate has a coefficient of thermal expansion α ガラス which is at least 2×10 -6 1 / K, preferably 10×10 -6 1 / K higher coefficient of thermal expansion α 基体 it is even more preferable, and preferably, α 基体 is in the range of 11×10 -6 1 / K~18×10 -6 1 / K. Just with the combination of one or in particular both of the above states of the coefficient of thermal expansion of special steel and the fixing material, particularly preferably, a stable feed-through is achieved, particularly a compression-type glass-metal seal.

[0040] The special steel for the metal pins can preferably be selected from the group of ferritic special steel, martensitic special steel, or precipitation-hardening special steel. Ferritic special steel is particularly preferred because it is produced particularly efficiently and / or supplied to the manufacturing apparatus particularly efficiently.

[0041] In a preferred embodiment, at least one metal pin has at least one bending point. Preferably, the metal pin is bent such that an axial offset S occurs between the region of the metal pin within the through-hole and the connection region at the end of the metal pin on the opposite side of said region. Thereby, a through-hole arranged in the center of the substrate can be realized particularly well.

[0042] Furthermore, a bent metal pin, in particular a metal pin bent in an S-shape, can provide a kind of spring function when assembled to a connector when a special steel according to the invention is used as the material for the metal pin. Thereby, when inserting into the connector, for example, the possibility of damage to the connector system such as the metal sleeve being pushed out from the plastic holder is reduced. Furthermore, the peak of the mechanical load is borne by the glass material of the feed-through.

[0043] The production of the bent metal pin is more difficult with the special steel according to the invention than with the NiFe steel used heretofore. This is because the bending is carried out after annealing, and as is apparent from the hardness as described above, the annealed special steel is only plastically deformed by applying a greater force.

[0044] Preferably, the metal fixing material feed-through has at least one further metal pin which is conductively connected to the substrate, in particular by soldering or welding. Thereby, a direct electrical contact between the substrate and the second metal pin is formed, so that a second through-hole in the substrate can be omitted.

[0045] In a preferred embodiment, the metal pin conductively connected to the substrate is made of non - special steel, especially NiFe, at least in its core region, and this metal pin is connected to the substrate by welding. Preferably, in this case, this metal pin exists in an annealed - free state, except for at least the region of the welded connection heated during welding. Such a material selection has the advantage that, as described above, unprocessed non - special steel is mechanically more load - resistant than annealed special steel. Therefore, such an embodiment has the best mechanical strength values. However, producing a welded connection is more labor - intensive than brazing a second metal pin to the substrate.

[0046] In a preferred embodiment, this other metal pin also has at least one bending point. Preferably, this other metal pin is bent so that an offset occurs between the axis of the region of this metal pin connected to the substrate and the connection region at the end of this metal pin on the opposite side of said region.

[0047] To optimize the brazing of a metal pin made of special steel with a metal brazing material, at least one metal pin hermetically sealed with glass in a through - hole and / or the metal pin conductively connected to the substrate preferably has a nickel coating. Preferably, the nickel coating is provided at least in the region of the glass seal, and / or in the region of the head surface of the metal pin hermetically sealed with glass, and / or in the region conductively connected to the substrate. Additionally or alternatively to the nickel coating, a gold layer may also be provided.

[0048] Particularly preferably, the gold layer is provided on the nickel layer at least in a predetermined region.

[0049] Therefore, in particular, the nickel coating is - in the region where a gold layer is provided on at least the region of the nickel layer of the glass - sealed metal pin, especially in the connection region at the end of this metal pin, and / or - in the region where the glass - sealed metal pin is in contact with the fixing material. and / or - in a region where a gold layer is provided on at least a region of a nickel layer of a metal pin conductively connected to a substrate, in particular in a connection region at an end of the metal pin and / or - in a region where a metal pin conductively connected to a substrate is connected to the substrate by a metallic solder material is possible.

[0050] To ensure a reliable electrical connection, at least one metal pin hermetically sealed in a through-hole and / or a metal pin conductively connected to a substrate is preferably gold-coated in at least a predetermined region. Preferably, the gold layer is provided at least in a connection region and / or in a connection region of a metal pin conductively connected to a substrate. The connection region is in particular a region where the metal pin is inserted into, for example, a connector system and / or a region where the metal pin contacts a contact of the connector system.

[0051] In order to provide a metal fixing material feed-through with metal pins that can be processed or assembled as simply as possible, in such a form of metal fixing material feed-through, the metal pins, in the annealed state, in a test system having a metal pin length L of 11.68 mm, when a vertical load is applied at the end point L, have a force F max that breaks when exceeding 2.2 N. The metal pins further, in the annealed state, in a test system having a metal pin length L of 11.68 mm, when a vertical load is applied at the end point L, can be designed to be elastically deformable up to a maximum displacement W max exceeding 0.15 mm, in particular 0.15 mm to 0.4 mm. Thus, W max is the limit value of elastic deformation. When a load exceeding W max is applied, plastic deformation occurs, i.e., a permanent bending of the metal pin takes place.

[0052] If the actual metal pin has dimensions different from those of the above test system, then for the purpose of comparison, this metal pin is fabricated to the dimensions of the test system and / or its measurement results are converted to correspond to the dimensions of the test system.

[0053] The metal pin according to the present invention made of special steel has a significantly higher hardness than the NiFe pin after glass sealing and after heating to 600 °C or 650 °C. This is due to the fact that NiFe softens at high temperatures while special steel does not. Therefore, with special steel, a pin load 50% higher than that of NiFe, for example, is possible after fusion bonding.

[0054] The metal fixing material feed-through provided with a metal pin made of special steel is excellent due to the extremely high mechanical stability of the metal pin. The high mechanical stability prevents bending of the metal pin during assembly and post-processing, especially continuous or plastic bending. The use of special steel as the pin material ensures that the mechanical stability is significantly enhanced compared to pins made of, for example, NiFe material.

[0055] Furthermore, the metal pin according to the present invention in a metal fixing material feed-through for an igniter of an airbag or a seat belt pretensioner is, unexpectedly, excellent in having an extremely high extraction force exceeding 250 N, particularly in the range of 250 N to 400 N, preferably 300 N to 380 N. This was surprising to those skilled in the art. Because the coefficient of thermal expansion of a pin made of special steel is in the range of 11.0×10 -6 / K to 13.5×10 -6 / K at 650 °C and thus is in a different range from the glass material and the metal around the metal fixing material feed-through, a relatively low extraction force was expected, and thus the use of a metal pin made of special steel was considered disadvantageous. Such a relatively high extraction force is thought to be due to improved chemical adhesion of the pin in the glass material based on the selected pin material.

[0056] In a further embodiment, the special steel of at least one metal pin is selected from the group of special steels in which the transition point from elastic deformation to plastic deformation in the annealed state is lower than 50% of the transition point from elastic deformation to plastic deformation in the unprocessed state.

[0057] By such a selection, after the metal pin is mounted into the fixing material, particularly the glass material, and then after being mounted into the opening of the substrate of the metal fixing material feed-through by heating the substrate to at least 600 °C or 650 °C, it is ensured that the metal pin does not soften so much that it can undergo plastic deformation under the mechanical loads that often occur. Since the transition point from elastic deformation to plastic deformation of the annealed metal pin is significantly reduced, the strength of the metal pin, and thus its mechanical stability, will be significantly reduced.

[0058] The transition point from elastic deformation to plastic deformation in the unprocessed ferritic special steel is located at a stress of 600 MPa and decreases to 500 MPa in the stress-strain graph by heating to 600 °C. In the case of NiFe, the transition point of 700 MPa decreases to 300 MPa in the stress-strain graph by heating to 600 °C. This means that NiFe steel is much more mechanically stable than the special steel according to the invention in the non-annealed state. However, in the annealed state, the special steel is more mechanically load-resistant and can be elastically deformed, especially up to relatively high loads.

[0059] The special steel does not soften as much as NiFe in the annealed state, so it is more difficult to mechanically process the special steel compared to NiFe. This is manifested, for example, in the difficult bending characteristics when forming an S-shaped bend of the metal pin, as well as in the more difficult processing related to the forming of the end of the metal pin, such as grinding or embossing of a portion with a radius of curvature. In particular, due to the incompatible state of the coefficient of thermal expansion and the difficult post-processing, those skilled in the art have refrained from using special steel instead of NiFe as the material for the metal pin.

[0060] The advantage of special steel as a pin material over conventional materials, such as NiFe, is that when combined with a substrate made of special steel, galvanic corrosion does not actually occur when the bridge wire is connected or when coated with a conductive film. This is due to the small difference in electrochemical potential between the substrate made of special steel and the metal pin made of special steel. The absolute value of the difference in electrochemical potential between the metal pin, especially the glass-sealed metal pin, and the substrate is made to be at most 0.3V. That is, the absolute value of the difference in electrochemical potential between the metal pin, especially the glass-sealed metal pin, and the substrate is preferably in the range of 0 to 0.3V. Thereby, galvanic corrosion can be actually prevented from occurring. On the other hand, when using NiFe pins, electrons move from the NiFe pins to the material of the substrate made of, for example, austenitic special steel, and galvanic corrosion occurs. For example, when using a ferritic special steel as the material for the metal pin, the electrical potential between the metal pin and the substrate made of austenitic special steel is substantially the same magnitude, and unlike NiFe pins, galvanic corrosion does not occur.

[0061] Furthermore, it is also described that according to the present invention, the selection of materials for the substrate and / or the metal pin can be suitably made based on the electrochemical potential with respect to seawater. In the operating state, especially over a long storage period or operating period, the film formed on the surface of the feedthrough may have the same corrosiveness as seawater, so this potential with respect to seawater is a suitable criterion for judging the resistance to electrochemical corrosion action.

[0062] According to such a concept of the present invention, the materials for the selection of the substrate and / or at least one metal pin, especially the metal pin located within the fixing material, are especially special steels in which the absolute value of the electrochemical potential with respect to seawater is at most 0.36V, that is, correspondingly, in the range of 0 to 0.36V.

[0063] Special steel as the pin material has a very small electrochemical potential difference with respect to the special steel as the substrate material. Therefore, it is a metal fixing material feed-through for an igniter of an airbag and / or a seatbelt pretensioner, having at least one metal pin fused into the through-hole of the substrate within a glass or glass-ceramic fixing material. At least one metal pin and the substrate are composed of a compatible material combination. In a state where the ignition bridge is attached, an anodic reaction and / or a cathodic reaction do not occur on the surface of the substrate. In this case, the surface of the feed-through is defined as the side where the ignition bridge should be attached, and the lower surface is defined as the side of the electrical connection part, that is, the side of the metal fixing material feed-through where the metal pin protrudes. A metal fixing material feed-through can be provided.

[0064] If at least one metal pin and the substrate have substantially the same electrochemical potential, this is particularly suitable because in a state where the ignition bridge is attached, electrons do not flow through the ignition bridge via an absorbent water film on the water surface. Preferably, the absolute value of the difference in the electrochemical potential between the substrate and the special steel pin is simply 0.3V to 0.0V. That is, for example, the substrate has a potential of 0.07V and the metal pin has a potential of 0.02V, so that the difference is 0.05V. Therefore, in fact, no electron flow occurs from the metal pin to the substrate via the ignition bridge and / or via the conductive film.

[0065] It is particularly suitable that the proportion of Cr in the special steel is in the range of 10 wt% to 30 wt%, preferably in the range of 15 wt% to 25 wt%. Therefore, for example, when the proportion of chromium is 20 wt%, a very low linear expansion coefficient of about 10×10 -6 / K is achieved at 0 to 40°C. The low thermal expansion coefficient at 40°C is also related to the low thermal expansion coefficient at the glass sealing temperature of usually 600°C or 650°C.

[0066] In order to enable brazing of metal pins made of special steel, as described above, a Ni layer and / or a gold layer are provided on the metal pins at least in a predetermined region. In this case, the nickel layer can also be provided under the gold layer. It is also possible to directly gold-plate the special steel without a nickel intermediate layer.

[0067] Surprisingly, when special steel is used as the material of the metal pin, it has been confirmed that the removal force of the metal pin from the glass material is in the range of 250 N to 400 N, preferably 300 N to 380 N. Such a removal force is unexpectedly about 50% greater than that of, for example, NiFe metal pins.

[0068] When the metal pin has a metal pin length L of 11.68 mm in a heat-treated state and a vertical load is applied at the end point L, a force F exceeding 2.2 N max If it is designed to break, and / or when the metal pin has a metal pin length L of 11.68 mm in a post-heated state and a vertical load is applied at the end point L, a maximum displacement W exceeding 0.15 mm, particularly 0.15 mm to 0.4 mm max If it is designed to break, the metal fixing material feed-through has particularly stable metal pins. Such stable metal pins are formed especially when special steel, particularly chromium-containing special steel, is used as the material for the metal pins.

[0069] The thermal expansion coefficient of this steel having 11.0 to 13.5×10 at 650 °C -6 / K is 10.6 to 6.1×10 -6Since it is significantly higher than the expansion coefficient of the glass within the range of / K, those skilled in the art have hitherto refrained from using special steel in compression-type glass feed-throughs, for example, for use in airbag igniters. Surprisingly, the inventors have found that in a glass-metal feed-through, contrary to the prior art which stipulates that for providing sufficient sealing, the thermal expansion of the conductor must not be higher than the thermal expansion of the glass used, even though the thermal expansion coefficient of the conductor is higher than that of the glass, if a positive joining pressure from the substrate to the glass is applied even when the expansion coefficient of the metal pin is greater than that of the glass, a tight glass seal is provided. If the joining pressure is greater than 30 MPa, preferably greater than 50 MPa, particularly greater than 100 MPa, it is particularly suitable. At such a joining pressure, a reliable glass seal can be obtained. The joining pressure is the pressure at the location of the transition from the substrate to the glass material. This pressure usually acts perpendicularly from the inner wall of the through-hole to the glass body in a compression-type glass-metal seal. This pressure is an important factor regarding the removal force of the glass body from the substrate.

[0070] If a sufficient preload is applied to the glass from the substrate as the outer conductor, a high joining pressure is provided. The joining pressure that occurs in this case between the glass and the inner conductor occurs during the cooling of the feed-through after fusion. If this joining pressure is extremely positive, i.e., greater than 30 MPa, or greater than 50 MPa, particularly greater than 100 MPa, the transition between the glass and the metal is maintained, i.e., the transition from the glass to the metal pin is closed, and thus it is sealed even though the expansion coefficient of the metal pin is greater than that of the glass.

[0071] The joining pressure depends directly on the difference in strain between the glass and the surrounding metal. Furthermore, dependence on the geometry is also conceivable. Particularly advantageously, the area of the substrate outside the through-hole must be larger than the area of the through-hole itself. The joining pressure is a surface pressure. The joining pressure is represented by the force per unit area that presses the first object against the second object.

[0072] To provide the necessary joining pressure, the difference between the coefficient of thermal expansion of the substrate and that of the glass is at least 2 ppm / K, preferably at least 4 ppm / K. In this case, the coefficient of thermal expansion α 基体 is higher than the coefficient of thermal expansion α ガラス of the glass. In a particularly preferred embodiment, the coefficient of thermal expansion of the metal pin is such that it is 1.1 times greater than the coefficient of thermal expansion α ガラス of the glass, and the coefficient of thermal expansion α 金属ピン of the metal pin is selected. In a particularly preferred embodiment, the coefficient of thermal expansion is in the range of 1.1α ガラス to 2.2α ガラス .

[0073] To apply the necessary pressure from the substrate to the glass material and ensure sealing performance, the substrate is made of nickel-free, chemically resistant stainless steel (special steel).

[0074] It is preferable that the substrate, which may be the outer conductor, is austenitic stainless steel with excellent weldability.

[0075] In addition to straight metal pins, the metal pins of the metal fixing material feed-through are not formed straight and may be bent.

[0076] The fixing material of the metal fixing material feed-through is a glass material or a glass-ceramic material. The coefficient of thermal expansion α ガラス of the glass material used is in the range of 4×10 -6 / K to 10.6×10 -6 / K, preferably in the range of 6.1×10 -6 / K to 10.6×10 -6 / K.

[0077] The substrate of the metal-fixed material feed-through, in which the metal pins are glass-sealed, may have openings in various forms, as described, for example, in European Patent Application Publication No. 1813906, European Patent Application Publication No. 1455160, or European Patent Application Publication No. 2431703. Cold forming as described in European Patent Application Publication No. 2431703 is one possibility, in which case the openings are provided in the substrate by punching.

[0078] In a compression-type glass feed-through, such as is used in the igniters of airbags and seat belt pretensioners, the material of the substrate is selected such that the coefficient of expansion α 基体 is greater than the coefficient of expansion of the glass material, so that pressure is applied to the glass material, thereby effecting a compression-type glass-metal seal. In a compression-type glass-metal seal, a substrate made of austenitic special steel with a coefficient of expansion α = 18.3×10 -6 / K is suitable.

[0079] A further aspect of the invention is to provide a metal-fixed material feed-through for an igniter of an airbag and / or a seat belt pretensioner, in which galvanic corrosion occurs only to a small extent. This aspect is achieved in that at least one metal pin of the feed-through and the substrate are composed of a compatible material combination, and in a state where the ignition bridge is attached or the surface is coated with a conductive film, an anodic reaction and / or a cathodic reaction on the surface of the substrate does not occur or occurs only to a small extent.

[0080] At least one metal pin and the substrate have an electrochemical potential, and if the absolute value of the difference in the electrochemical potential between the metal pin and the substrate is at most 0.3 V, it is particularly preferred. Preferably, the electrochemical potentials of the metal pin and the substrate are substantially the same. In particular, the absolute value of the difference in the electrochemical potential between the metal pin and the substrate is in the range of 0.1 V to 0.0 V, preferably 0.05 V to 0.0 V. The absolute value of the difference in the electrochemical potential of the metal pin and / or the substrate with respect to seawater is preferably at most 0.36 V, and in particular in the range of 0.36 V to 0.0 V.

[0081] At least one metal pin (5) consists, in particular at least in its core region, and the substrate consists at least in its upper surface, of special steel according to the EN 10020 standard.

[0082] In a further embodiment, the special steel of the metal pin and the substrate is selected such that the special steel of the metal pin and the substrate forms a passivation film on its surface, preferably facing an absorbent water film.

[0083] At least one metal pin consists, at least in its core region, of special steel according to the EN 10020 standard, and its coefficient of thermal expansion α at a temperature of 650 °C 金属ピン is in the range of 9 to 15, preferably 11.0×10 -6 / K to 14.0×10 -6 / K, preferably 11.5×10 -6 / K to 14.0×10 -6 1 / K, or 11×10 -6 / K to 13.5×10 -6 1 / K, particularly preferably 11.5×10 -6 / K to 12.5×10 -6 1 / K.

[0084] The glass or glass-ceramic fixing material preferably has a coefficient of thermal expansion α in the range of 4×10 -6 1 / K to 10.6×10 -6 1 / K up to the Tg of this fixing material. ガラス

[0085] The substrate has a coefficient of thermal expansion α of glass ガラス by at least 2×10 -6 1 / K, preferably 10×10 -6 1 / K higher, preferably 11×10 -6 1 / K to 18×10 -6 1 / K, and it is particularly preferred if it has a coefficient of thermal expansion α in the range of 基体 .

[0086] The special steel of at least one metal pin (5) is an alloy special steel based on the standard of EN10020 in particular, and is particularly preferably a chromium-containing special steel. Particularly preferably, the special steel is selected from the group of ferritic special steels and / or precipitation-hardening special steels. The extraction force of the metal pin from the glass material of the through-hole (4) is preferably higher than 250 N, particularly 250 N to 400 N, and preferably 300 N to 380 N.

[0087] In particular, the substrate is made of or substantially contains metal, particularly steel, stainless steel, special steel, titanium, titanium alloy, magnesium, magnesium alloy, aluminum alloy, aluminum. Most particularly preferably, the substrate consists of at least substantially special steels of type 316, 317, 302, 304, 321, 317, 430, 410, and / or 416.

[0088] The metal pin is converted to standard dimensions having a metal pin diameter of 1.00±0.03 mm and a metal pin length of 11.68±0.2 mm, and has a maximum elastic deflection W of less than 0.13 mm, preferably less than 0.15 mm, particularly preferably less than 0.18 mm or less than 0.20 mm, most particularly preferably less than 0.24 mm, and particularly in the range of 0.01 to 0.26 mm max .

[0089] The metal pin conductively connected to the substrate is made of non-special steel, particularly NiFe, at least in its core region, and this metal pin is connected to the substrate by welding.

[0090] In a further configuration of the invention, at least one metal pin (5) hermetically sealed in the through-hole and / or a metal pin (6) electrically connected to the substrate may be nickel-coated. Preferably, the nickel layer is - in a region where a gold layer is provided on at least the region of the nickel layer of the glass-sealed metal pin, particularly in the connection region at the end of the metal pin, - in the region of the glass-sealed metal pin that is in contact with the fixing material, - in a region where a gold layer is provided on at least the region of the nickel layer of the metal pin electrically connected to the substrate, particularly in the connection region at the end of the metal pin, - in the region of the metal pin electrically connected to the substrate where the metal pin is connected to the substrate by a metallic solder material, present in the region of the metal pin selected from the group of and combinations of these groups.

[0091] Alternatively or additionally, at least one metal pin hermetically sealed in the through-hole and / or a metal pin electrically connected to the substrate may be gold-coated. Preferably, the gold layer is provided in at least the connection region of the metal pin and / or the metal pin electrically connected to the substrate, which is located on the opposite side of the end of each metal pin located inside and / or on the substrate surface of the substrate.

[0092] The present invention will be described in detail below with reference to the drawings and embodiments, but the present invention is not limited to these embodiments.

Brief Description of the Drawings

[0093]

Figure 1a

Figure 1b

Figure 2

Figure 3a

Figure 3b

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10a

Figure 10b

Figure 10c

Figure 11

Mode for Carrying Out the Invention

[0094] Figure 1a shows an exemplary configuration of a metal fixing material feed-through 1 for use in an igniter or ignition device of an airbag or other personal protection device, such as a seatbelt pretensioner, preferably as described in, for example, European Patent Application Publication No. 2270417, in an axial cross-sectional view. The metal fixing material feed-through includes, but is not limited to, two metal pins 5, 6 formed as metal pins according to the present invention and including special steel as the material of the metal pins. The metal fixing material feed-through has a base 1, to which, in this embodiment, one of two metal pins 5, 6 parallel to each other is electrically connected. Both metal pins 5, 6 are arranged parallel to each other in the illustrated embodiment. In this case, one functions as a conductor and the other is arranged on the ground. In the illustrated example, the first metal pin 5 functions as a conductor and the metal pin 6 functions as a ground pin. The ground pin 6 is conductively connected to the base 1, for example, by a brazing joint 7 with a brazing material. The width of both metal pins is usually in the range of 0.98 to 1.05 mm, preferably 1.0 mm.

[0095] At least one of the metal pins, in particular the metal pin 5 which functions as a conductor, is guided through the base body 1. For this purpose, the metal pin 5 is fused over a portion of its length into the fastening material 10, in particular into the glass stopper which has been cooled from the glass melt. The metal pin 5 protrudes at least on one side beyond the end face of the glass stopper 10, usually on the underside of the base body, and in the illustrated embodiment is flush with a second end face of the glass stopper 10 which is flush with the upper face 11 of the base body 1 after completion of production. For this purpose, the metal pin 5 can be arranged in the through hole 4 in such a way that during fusion, it first protrudes beyond the base body 1. After fusion or embedding, the metal pin 5 and possibly the protruding and cooled fastening material 10 can be polished so that it and / or the fastening material are flush with the end face of the glass stopper 10 and with the upper face 11 of the base body 1. Further variants are also conceivable. The fusing of the metal pin into the glass material and the fusing of the glass material into the substrate are usually carried out at temperatures above 600°C or 650°C, depending on the glass material used. 基体 ~18.3×10 -6 / K is 4 x 10 -6 / K~10.6×10 -6 Thermal expansion coefficient α in the range of / K ガラス材料 Due to the fact that the thermal expansion coefficient of NiFe is higher than that of the glass material, after cooling, the substrate exerts a certain pressure on the fastening material, in particular on the glass material, and a compressive glass seal is produced. However, on the other hand, the mechanical stability of the metal pins is also affected by heating, i.e., the metal pins are generally softened under temperature action. The inventors have realized that when used for feedthroughs, the special steel does not soften as significantly as NiFe under temperature action. The special steel maintains a significantly higher bending stiffness than the NiFe pins currently used in feedthroughs.

[0096] The earth pin 6 is attached in the illustrated case directly to the rear side of the substrate 1, for example by means of a solder material 7. This is usually a metallic solder material. The earth pin 6, like the glass-sealed metal pin 5, may also consist according to the invention of special steel, preferably a Cr-containing special steel.

[0097] In one embodiment, the substrate 1 may be formed as a punched part. If at least the through-hole 4 and preferably also the final geometry of the substrate 1 are formed by punching, it is a punched part. According to one embodiment, the geometry that outlines the outer contour, in particular the outer contour of the substrate 1, can be produced by shearing, preferably by punching. The punched part can be used further while maintaining the geometry after the punching process, but it may preferably be deformed in a further working step immediately following it, for example by embossing or deep drawing. Alternatively, the entire substrate can be formed by a cold forming process as described in EP 2 431 703 A1.

[0098] The through-hole 4 provided for receiving and fixing the metal pin 5 by the glass plug 10 is formed in the form of a hole by a punching process. Thereafter, the metal pin 5 is introduced into the through-hole 4 together with the glass plug 10 on the back surface 11 of the substrate 1 of the metal fixing material feed-through, and the metal body including the glass plug 10 and the metal pin 5 is heated to about 600 °C. As a result, after the cooling process, the metal shrinks, and a frictionally connected bond is formed between the glass plug 10 including the metal pin 5 and the substrate 1, which is also called a compression-type glass-metal seal. Such a compression-type glass-metal seal can be performed based on the difference in the thermal expansion coefficients of the substrate 1 and the glass material of the glass plug 10.

[0099] In an alternative configuration, it is also conceivable to introduce the fixing material 10, in particular a glass melt, into the through-hole from the front in a molten or flowing state. In this case, during cooling, a form-fitting and material-fitting bond is formed between the outer circumference of the metal pin 5 and the inner circumference of the through-hole 4. The substrate 1 may be configured such that the ratio between the thickness of the substrate 1 and the maximum extent of the through-hole 4 in a direction perpendicular to the axial direction of the through-hole 4 is in the range of 0.5 to 2.5.

[0100] It should be emphasized that the present invention can also be implemented by an insulating material within a through hole 4 that is not based on a glass material.

[0101] Figure 1a shows the attachment of a metal fixation material feedthrough in an igniter component, for example an airbag igniter. The igniter component includes, in addition to a metal fixation material feedthrough in which a metal pin 5 is glass-sealed inside, an igniter cap 2 for the igniter component, i.e., for accommodating the gunpowder 25 of the airbag igniter. The gunpowder 25 is triggered by an electrical impulse of a bridge wire 9. The bridge wire 9 connects the glass-sealed metal pin 5 to a substrate 1 arranged on the ground. Usually, the bridge wire 9 is placed on the surface of the substrate 1 and / or the fixation material 10, different from the drawing which schematically shows the bridge wire 9.

[0102] Figure 1a also shows the bending point 50 of the glass-sealed metal pin, which causes an axial offset S between the region of the metal pin 5 glass-sealed within the through hole and the connection region of the metal pin. This offset is selected such that the metal pin of the metal fixation material feedthrough can be introduced, for example, into a connector system. Usually, both metal pins 5, 6 are arranged and / or bent such that, when viewed in the overall figure, there is a central arrangement of one of the two metal pins 5, 6 with respect to the substrate 1.

[0103] Figure 1b shows a cross-section of a metal fixing material feed-through mounted in an igniter cap 2, including a substrate 1 with metal pins 5, 6. The same reference numerals are assigned to the same components as in Figure 1a. Different from the embodiment shown in Figure 1a, in the configuration of Figure 1b, the metal pin 6 also has a bending point 60, so there is an offset of the axis between the region of the metal pin connected to the substrate 1 and the connection region of the metal pin at the opposite end. In Figure 1b, a bridge wire 9 between the substrate 1 and the metal pin 5 is clearly shown. Different from the punched substrate of Figure 1a, the substrate of Figure 1b is a substrate cold-formed as described in European Patent Application Publication No. 2431703 and has an open region 17. After providing the open region 17 as described in European Patent Application Publication No. 2431703, an opening 10 is punched from the cold-formed substrate.

[0104] Figure 2 shows a measuring device or test system for detecting the bending strength of a metal pin. Figure 2 shows a clamped metal pin 300 with a length L = 11.68 mm and a diameter of 1.0 mm, and a force F in units of Newton (N) indicated by reference numeral 110 acts on this pin.

[0105] As shown in Figure 2, in the test system or measuring device, the wall on which the pin is clamped is indicated by reference numeral 400, the pin with length L is indicated by reference numeral 300, and the end point of the metal pin in the unloaded state is indicated by reference numeral 301. The bent, i.e., loaded, pin is indicated by reference numeral 310, and the end point of the bent pin is indicated by reference numeral 302. The difference between the end points 301 and 302 represents the maximum displacement W max is shown.

[0106] In the as-received NiFe metal pin, when a force of 6.380 N is applied, a deflection of 0.345 mm occurs. At greater forces and greater deflections, the elastic deformation transitions to irreversible plastic deformation. In the case of plastic deformation of the pin with a force exceeding 6.380 N and / or a bend exceeding 0.345 mm, the pin may be damaged.

[0107] When the NiFe pin is heated to a glass sealing temperature of, for example, 650 °C, after cooling (annealing), with only a force of 1.933 N applied to this metal pin, the deflection becomes 0.105 mm. In the annealed state, with a force exceeding 1.933 N and a deflection exceeding 0.105 mm, as described above for the unprocessed state, elastic deformation transitions to plastic deformation. Such considerations regarding the application of force indicate that the NiFe pin significantly loses its mechanical stability upon heating.

[0108] In contrast, when using special steel, such as ferritic special steel, particularly AISI 430, in the unprocessed state, plastic deformation occurs only when the force exceeds 4.976 N and the deflection exceeds 0.269 mm W max and in the annealed state, plastic deformation occurs when the force exceeds 3.984 N and / or the deflection exceeds 0.216 mm W max This indicates that, for example, after heat treatment at 650 °C, the mechanical stability and / or the maximum achievable deflection potential of ferritic special steel (AISI 430) in the test system is approximately 100% higher than that of the NiFe47 pin.

[0109] The above W max values in these examples represent the boundary values where elastic bending of the metal pin still exists. When the mechanical load in this example exceeds the above boundary values, of course, the bending occurs beyond the above values of W max but this is plastic deformation, that is, irreversible.

[0110] This actually means that, unlike the NiFe47 pin, which softens extremely significantly during the glass sealing process at a temperature of, for example, 650 °C, the special steel pin is significantly more bending - rigid. Therefore, with special steel, in a test system with a metal pin length L of 11.68 mm after heating, that is, in the annealed state, the vertical load at the final point exceeds 2.5 N, preferably exceeds 3 N, particularly preferably exceeds 3.2 N or 3.5 N, and in this example, a force F of 3.984 N maxMaterials are provided that allow the design of metal pins such that plastic deformation occurs only after a certain point.

[0111] This also means that the maximum elastic bendability and / or displacement W in the above test system max is preferably greater than 0.15 mm, particularly in the range of 0.15 mm to 0.3 mm and / or 0.4 mm.

[0112] This significantly reduces the risk that the metal pins will be damaged under mechanical loads during post-processing, particularly when bending forces are applied during assembly, according to the present invention.

[0113] Figures 3a and 3b show the difference in the coefficient of thermal expansion between a conventional feed-through and a feed-through according to the present invention.

[0114] Figure 3a shows the coefficient of thermal expansion in a conventional metal fixing material feed-through. In this case, CTE(H) is the coefficient of thermal expansion α 基体 of the substrate or header, CTE(G) is the coefficient of thermal expansion α ガラス of the fixing material, and CTE(P) is the coefficient of thermal expansion α 金属ピン of the metal pins arranged within the fixing material. As is apparent from Figure 3a, in order to provide a compression-type glass-metal seal, the coefficient of thermal expansion of the substrate (CTE(H)) is significantly greater than that of the fixing material, particularly the glass (CTE(G)). For example, when using austenitic stainless steel as the substrate material, the coefficient of thermal expansion of the substrate (CTE(H)) is in the range of 18.3×10 -6 / K. The coefficient of thermal expansion of the glass material (CTE(G)), also referred to as α ガラス , is typically 4×10 -6 / K to 10.6×10 -6It is in the range of / K, which is significantly lower than the coefficient of thermal expansion CTE(H) of the substrate. In the prior art, the coefficient of thermal expansion CTE(P) of the metal pin was always lower than that of the surrounding glass material, even if only slightly. Until now, it has been assumed that this is necessary to achieve a durable fixed material feedthrough, because otherwise the metal pin may come off the glass during thermal fluctuations. Therefore, until now, metal pins made of non-special steel, especially NiFe, have been used for such applications.

[0115] Figure 3b shows the coefficient of thermal expansion of the feedthrough according to the present invention provided with a metal pin made of special steel. As can be seen from Figure 3b, the coefficient of thermal expansion (CTE(P)) of the metal pin is lower than that of the substrate (CTE(H)), but higher than that of the fixed material (CTE(G)). Special steel has a coefficient of thermal expansion in the range of 11.0 - 13.5×10 -6 / K, but the coefficient of thermal expansion of the fixed material, such as glass, is usually simply 4×10 -6 / K - 10.6×10 -6 / K, especially in the range of 6.1×10 -6 / K - 10.6×10 -6 / K, that is, lower than the coefficient of thermal expansion of the metal pin. Therefore, the coefficient of thermal expansion of the metal pin is higher than that of the glass material, unlike the prior art shown in Figure 3a, but if a positive joining pressure is applied from the substrate having the coefficient of expansion α 基体 or CTE(H) to the glass, it is possible to provide sufficient sealing performance and compression-type glass-metal sealing for the metal pin made of special steel with α 金属ピン >α ガラス according to the present invention. When a high joining pressure is applied from the substrate to the glass material and the metal pin, the transition portion between the glass and the metal, especially the transition portion from the glass to the metal pin, remains closed and the sealing performance is guaranteed. In particular, airtight sealing can also be achieved. When viewed in plan view, if the area of the substrate minus the area of the through hole corresponds to at least 1.2 times the area of the through hole, a sufficiently high joining pressure can preferably be reached.

[0116] Figure 4 shows the stress-strain curves for the special steel pins according to the present invention and, for comparison, the stress-strain curve for a NiFe pin (NiFe47). As is clearly evident from Figure 4, the NiFe pin, especially when compared to a special steel pin (AISI430) made of a ferritic special steel, loses its stability significantly and becomes brittle after heating up to, for example, 650 °C, which is required for glass sealing. Thus, in the case of the ferritic special steel AISI430, the transition point from elastic deformation to plastic deformation, which is at a strain of approximately 0.25%, simply shifts from a stress of approximately 600 MPa for the unprocessed material to a stress of 500 MPa for the annealed material. That is, the stress at the transition point only decreases by approximately 20%. In contrast, in the case of the NiFe metal pin, the transition point from elastic deformation to plastic deformation, which is at a strain of approximately 0.25% during heating, shifts from a stress of 700 MPa to a stress of 200 MPa, that is, the transition point of the unprocessed material is 3.5 times higher than that of the annealed material. This indicates that the special steel material is more advantageous than NiFe as a pin material for a system in which the metal pin is present in a heat-treated, especially annealed state. This is even more noteworthy since the strength of the NiFe metal pin in the untreated, i.e., non-heat-treated state, is significantly higher than that of the special steel pin, so there is a premise that the conventional non-special steel pins are also suitable for such reasons in addition to the appropriate thermal expansion described.

[0117] Figure 5 shows a casing component in a plan view. The casing component includes an opening 1000, into which a pin 1020 is inserted and glass-sealed within a glass material 1010. Further, Figure 5 shows the joining pressure P1 from the glass material to the metal pin and the joining pressure P2 from the base or the casing component to the glass material. According to the present invention, when the expansion coefficient of the metal pin is higher than that of the glass material, a sufficient compressive preload of the base or the casing component must be applied to the glass for sufficient sealing performance. This is achieved especially if the geometric specifications described above are maintained.

[0118] Surprisingly, as shown in Figure 6, it can be seen that for special steel pins, a removal force up to 50% greater can be achieved by using special steel materials than with metal pins made of nickel-containing iron materials (NiFe47) that have been used so far. As shown in Figure 6, the removal force of NiFe47 is only 207.7 N for the uncoated material, and 225.2 N for the nickel-coated NiFe47 pins.

[0119] Surprisingly, a significantly high removal force can be achieved particularly by the metal pins according to the present invention made of a stainless steel material of a ferritic special steel. This is particularly surprising because, as explained, the state of the thermal expansion coefficient of the special steel pins is rather undesirable. For the ferritic special steel AISI446, a removal force of 331.2 N is achieved without nickel coating, and 358.1 N is achieved when nickel-coated. In the case of special steel AISI430, the removal force is somewhat lower. In this case, the removal force is 317.5 N without nickel coating and 327.3 N when nickel-coated. This shows that the metal pins made of special steel are superior not only by their high mechanical strength but also by their high removal force compared to the conventional NiFe metal pins. Therefore, the improved removal force of the metal pins made of special steel is presumably based on the fact that the material of the metal pins maintains a higher hardness than the material of the NiFe pins after heating, so that the special steel can withstand the joining pressure transmitted by the header to the metal pins through the glass with a greater force and is hardly pushed in, so to speak.

[0120] Coating one or more metal pins with nickel or gold or gold on top of a nickel coating not only provides a high removal force but also serves to make it easy to contact the metal pins.

[0121] FIG. 7 shows the influence of the chromium content in special steels on the coefficient of thermal expansion α or CTE(P) of special steels such as those used for metal pins. The linear expansion coefficient at 0 to 40 °C is shown in ppm / °C, i.e., ×10 -6 / K, for chromium contents from 0 to 60 weight percent. As can be seen from FIG. 7, for special steel AISI443 containing about 20 weight percent chromium, a coefficient of thermal expansion of 9.9×10 -6 / K is obtained. Generally, it can be seen that the CTE depends on the chromium content. According to FIG. 7, it can be seen that the local minimum value of the CTE is reached at a chromium content of about 20 weight %. That is, a special steel particularly suitable for metal pins is one whose chromium content is in the region around the local minimum value of the CTE, particularly in the range of 10 weight percent chromium content to 30 weight percent, and particularly preferably in the range of 14 weight percent to 28 weight percent chromium content. Special steels SUS430, AISI443, and SUH446 are within this range and can be particularly advantageously used as materials for metal pins. The same applies to AISI446 and AISI430.

[0122] As will be described later, materials having such a chromium content or chromium equivalent also have advantages regarding the electrochemical potential.

[0123] FIG. 9 shows the chromium equivalent and nickel equivalent of martensitic and austenitic special steels.

[0124] In addition to chromium, the chromium equivalent considering the proportions of molybdenum, silicon, and niobium is described for martensitic special steels and ferritic special steels. The chromium equivalent is in the range of 10 to 30 weight percent, particularly in the range of 12 weight percent to 28 weight percent. The particularly preferred range in the concept of the present invention is marked with a broken line in FIG. 9.

[0125] Generally, the special steel according to the present invention includes, or is, a chromium alloy steel, or has a predetermined chromium equivalent, where the chromium equivalent can be said to be %Cr + %Mo + 1.5 × %Si + 0.5 × %Nb. The chromium equivalent usually indicates an index of the whole ferrite-forming elements of austenitic special steel alloys according to the empirical formula of Scheffler and Delong. A particularly preferred range of the chromium equivalent is the range surrounded in FIG. 9.

[0126] FIG. 10a shows the head portion of the metal fixation material feed-through according to the present invention, and FIGS. 10b to 10c show schematic diagrams of electrochemical reactions in the region of the metal fixation material feed-through based on different electrochemical potentials in the prior art and the present invention.

[0127] Figure 10a first shows the head portion of the glass-metal fixing material feedthrough according to the invention, as shown in Figures 1a and 1b. The same components as in Figures 1a and 1b are given the same reference numerals. According to Figure 10a, a conductive film, for example a water film 200, may be formed on the surface of the substrate 1. As a result, when the electrochemical potential between the substrate and the metal pin is different, an electron flow from the metal pin to ground, in this case to the substrate 1, occurs, which may cause oxidation of the metal pin and / or the substrate, and / or the fixing material, for example the glass material. The electron flow from the metal pin to the substrate takes place via the bridge wire 9. The conductive film 200 may occur especially during the long-term use of the feedthrough of the type described at the beginning, and has a great influence on the long-term use of the feedthrough and the corrosive action on the feedthrough. Electrons flow from the head of the metal pin 500 to the substrate 501 via the bridge wire 9, or in the other direction depending on the potential difference in some cases. The insulating material between the substrate and the metal pin is usually a non-conductive fixing material, preferably a glass or glass-ceramic material. The glass or glass-ceramic material with a metallic conductor sealed inside is denoted by reference numeral 10. The metal pin guided through the opening is denoted by reference numeral 5, and the metal pin brazed to the substrate by the brazing material 7 is denoted by reference numeral 6.

[0128] Figure 10b shows the electron flow from the metal pin to the substrate due to the difference in electrochemical potential. This corresponds to the prior art. Therefore, the difference in electrochemical potential between a metal pin made of non-special steel, especially NiFe, and the substrate exceeds 0.3 V in the prior art. Based on such a difference in electrochemical potential, when a conductive layer exists on the metal pin and the substrate, for example when a water film 200 exists, iron is converted to Fe 2+ and two electrons are released and move to the substrate based on the existing electrical connection. When water is present, oxygen causes 2OH - to occur, that is, the water film becomes more and more basic, and the material of the metal pin oxidizes to Fe 2+This results. The same reference numerals as in Fig. 10a are also given in Fig. 10b. Thus, 500 indicates the region of the metal pin and 501 indicates the region of the substrate. The flow of electrons from the metal pin to the substrate occurs via the bridge wire 9 or, if the conductive film becomes increasingly basic as the reaction proceeds, even via the conductive film 200. The increase in the basicity of the film 200 may enhance the corrosive action on the metal and even on the glass material. The layer 5110 on the substrate made of special steel is a passivation layer formed on the special steel and can particularly contain oxygen. When NiFe is used as the pin material, it is observed that a local cell can be formed between this passivation layer 5110 and the non-special steel, particularly NiFe-made metal pin. The electrochemical potential difference between NiFe as the pin material and, for example, AISI 304L as the substrate material is 0.38V. In this case, there is a risk of electrochemical corrosion.

[0129] Therefore, in the prior art, the metal pin may corrode, but according to the present invention, since the metal pin has substantially the same electrochemical potential as the substrate given the reference numeral 501 in the region 500, corrosion no longer occurs or at least is significantly suppressed. As shown in Fig. 10c, even if a conductive film 200, particularly a water film, is provided on the substrate and the metal pin, no electron flow from the metal pin to the substrate occurs. The surface 5110 of the substrate and particularly of the metal pin is a passivation layer formed on the special steel that may contain oxygen but is not further oxidized. In particular, no increasingly basic water film is formed either.

[0130] When AISI 430 is used as the material of the glass-sealed metal pin and AISI 304 is used as the material of the substrate, the absolute value of the electrochemical potential difference is 0.02V. In this case, the electrochemical corrosive action is at least extremely significantly suppressed.

[0131] The same reference numerals are assigned to the same components as those in the drawings described above. Preferably, in the component according to the present invention, the absolute value of the difference in the electrochemical potential between the substrate and the special steel pin is simply 0.3V to 0.0V, preferably 0.1V to 0.0V, and particularly preferably 0.05V to 0.0V.

[0132] FIG. 11 shows the state of the electrochemical potential of materials that can be selected for the metal pin and / or for the substrate, particularly special steel. As explained, in order to obtain good corrosion resistance, a suitable material combination of the substrate and the metal pin in the fixing material is important. In the selection, efforts are made to cause as small a potential difference as possible. However, the material of the substrate must also meet other requirements. In particular, the substrate must be weldable to the metal cap 2, particularly by laser welding. In particular, when the substrate is punched or cold-formed, the manufacturing method of the substrate is also one aspect. When the substrate is cold-formed, a predetermined copper ratio may be advantageous.

[0133] When selecting the metal pins 5, 6, particularly the metal pin 5 arranged in the fixing material, and also for the selection of the material of the substrate, the materials listed as special steel in FIG. 11 are particularly suitable. They are special steel types (AISI) 316, 317, 302, 304, 321, 317, 430, 410, and / or 416. All of these have a relatively small electrochemical potential difference with respect to seawater, particularly an absolute value of less than 0.4V, preferably less than 0.36V, which, as explained, is a good measure for determining the resistance to galvanic corrosion effects for the entire feedthrough.

[0134] Therefore, on the one hand, for the first time, a metal fixing material feedthrough is provided by the present invention, which is excellent due to the relatively high mechanical stability, particularly when bending the metal pin, and / or due to the relatively high extraction force of the metal pin, and preferably also due to the relatively low corrosivity under particularly adverse use conditions.

[0135] Improved mechanical stability reduces assembly errors, which leads to improved reliability and / or reduced defective products. Improved corrosion resistance provides long-term stability and, thus, reliability of the device equipped with the feedthrough according to the present invention. Overall, the efficiency and safety of manufacturing an object including the feedthrough according to the present invention can be enhanced.

Claims

1. A metal fixing material feed-through for an igniter of an airbag and / or a seatbelt pretensioner, the metal fixing material feed-through having at least one metal pin (5) fused into a through-hole (4) of a substrate (1) within a fixing material (10) of glass or glass-ceramic, wherein The at least one metal pin (5) is made of special steel based on the standard EN 10020, at least in its core region, and the at least one metal pin (5) converted to standard dimensions having a metal pin diameter of 1.00 ± 0.03 mm and a metal pin length of 11.68 ± 0.02 mm has a maximum elastic deflection W in the range of 0.15 mm or more ｍａｘ and is selected such that it has The special steel of the at least one metal pin (5) has a coefficient of thermal expansion α at a temperature of 650 °C in the range of 9×10 －６ / K to 15×10 －６ / K and is selected accordingly, the at least one metal pin (5) hermetically sealed within the through-hole (4) is coated with nickel and / or gold, the at least one metal pin (5) has at least one bending point (50), the bending of the metal pin (5) is in an S-shape and is designed such that there is an offset (S) of the axis between the region of the metal pin (5) in the through-hole (4) and the connection region at the opposite end thereof, the metal fixing material feed-through (1) is designed as a compression-type glass feed-through, and in the metal fixing material feed-through (1), the substrate applies a joining pressure greater than 30 MPa to the glass or glass-ceramic fixing material, characterized in that it is a metal fixing material feed-through (1).

2. The special steel is selected such that under a mechanical load in the range of 3 N to 4 N, a displacement of up to 0.21 mm occurs, The metal fixing material feed-through (1) according to Claim 1.

3. A mechanical load of 0.25% (strain) of the at least one metal pin (5) corresponds to a stress exceeding 450 MPa, The metal fixing material feed-through (1) according to Claim 1 or 2.

4. The extraction force of the metal pin (5) from the fixing material (10) within the through-hole (4) is higher than 250 N, The metal fixing material feed-through (1) according to any one of Claims 1 to 3.

5. The substrate (1) is made of metal and / or substantially contains metal, The metal fixing material feed-through (1) according to any one of Claims 1 to 4.

6. The special steel of the at least one metal pin (5) is an alloy special steel based on the standard of EN10020, The metal fixing material feed-through (1) according to any one of Claims 1 to 5.

7. The fixing material for the glass or glass-ceramic has a coefficient of thermal expansion α in the range of 4×10 －６ / K to 10.6×10 －６ / K at a temperature up to the Tg of the fixing material. ガラス ​ The metal fixing material feed-through (1) according to any one of Claims 1 to 6.

8. The substrate has a coefficient of thermal expansion α ガラス that is at least 2×10 －６ / K higher than the coefficient of thermal expansion α 基体 of the glass. The metal fixing material feed-through (1) according to any one of Claims 1 to 7.

9. At least one further metal pin (6) is conductively connected to the substrate (1). The metal fixing material feed-through (1) according to any one of claims 1 to 8.

10. The further metal pin (6) conductively connected to the substrate consists of non-special steel at least in its core region, and the further metal pin (6) is connected to the substrate by welding. The metal fixing material feed-through (1) according to claim 9.

11. The further metal pin (6) has at least one bending point (60). The metal fixing material feed-through (1) according to claim 9.

12. The further metal pin (6) conductively connected to the substrate (1) is nickel-coated. The metal fixing material feed-through (1) according to claim 9.

13. The further metal pin (6) conductively connected to the substrate (1) is gold-coated. The metal fixing material feed-through (1) according to claim 9.

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