IGNITER FOR PASSENGER PROTECTION DEVICES AND METHOD FOR PRODUCING SAME

Abstract

An igniter of a passenger protection device has at least one metal pin for contacting the tripping unit of the passenger protection device. The metal pin has a contact end that can be coupled to the tripping unit. The metal pin has a gold coating with a layer thickness. A maximum layer thickness is present at a distance of at least 1 mm from the contact end.

Claims

1. An igniter of a passenger protection device, the igniter comprising: a metal pin having a contact end, wherein the contact end is not flat and is configured to contact a tripping unit of the passenger protection device; and a gold layer coating a section of the metal pin, the gold layer having a layer thickness with a maximum layer thickness being at a distance of at least 1 mm from the contact end.

2. The igniter according to claim 1, wherein the metal pin can be coupled by contact surfaces of a plug connector to the tripping unit at a distance from the contact end, wherein the maximum layer thickness is located at a region of the metal pin that is applied against the contact surfaces in an operating state.

3. The igniter according to claim 1, wherein the maximum layer thickness is located at a plateau region on the metal pin where the layer thickness varies by at most 40% of the maximum layer thickness.

4. The igniter according to claim 1, wherein the maximum layer thickness is between 0.20 μm and 0.80 μm.

5. The igniter according to claim 1, wherein the layer thickness of the gold layer is less than 0.20 μm.

6. The igniter according to claim 5, wherein the layer thickness of the gold layer is greater than 0.05 μm.

7. The igniter according to claim 1, wherein the metal pin has a length of more than 7 mm, and the layer thickness of the gold layer is more than 0.15 μm at 7 mm from the contact end.

8. The igniter according to claim 7, wherein the layer thickness of the gold layer at 7 mm from the contact end is less than 0.35 μm.

9. The igniter according to claim 3, wherein the metal pin has a length of 7 mm to 12 mm and a plateau region that begins at 1 mm to 4 mm from the contact end.

10. The igniter according to claim 3, wherein the plateau region terminates at 5 mm to 10 mm from the contact end.

11. The igniter according to claim 10, wherein the plateau region terminates at 5.5 mm to 7.5 mm from the contact end.

12. The igniter according to claim 3, wherein the plateau region has a length of between 2 mm and 6 mm.

13. The igniter according to claim 3, wherein the layer thickness of the gold layer increases from the contact end towards the plateau region by a slope of 0.1 to 0.3 and a 0.25 μm layer thickness per mm of distance from the contact end.

14. The igniter according to claim 1, wherein the metal pin is arranged in a sealing material of a metal sealing-material feedthrough with a base body or is connected to the base body in an electrically conductive manner by a solder connection or a weld connection.

15. The igniter according to claim 1, wherein the contact end is round.

16. A method for producing an igniter of airbags or seatbelt tensioners, the method comprising: applying a gold coating over a length of a metal pin, wherein the gold coating is applied so that a plateau region is formed on the metal pin at a distance of 1 mm to 5 mm from a contact end of the metal pin and beginning with a thickness of 0.10 μm to 0.80 μm over a length of 2 mm to 8 mm; inserting the metal pin in a glass or glass ceramic material; inserting the glass or glass ceramic material alone or together with a base body into a housing opening of a housing of the igniter; and heating the glass or glass ceramic material while applying a pressure glazing.

17. The method according to claim 16, wherein the applying the gold coating to the metal pin is by electrolytic deposition.

18. The method according to claim 16, wherein the applying the gold coating is by a blend technique in a single coating step.

19. The method according to claim 16, the method further comprising: diffusing nickel into the metal pin prior to the applying the gold coating.

20. A passenger protection device selected from the group consisting of: airbags, seatbelt tensioners, buckle tensioners, pyrotechnic actuators, active hinges, active buckles, active headrests, active steering columns, and battery separators, passenger protection device comprising: the igniter according to claim 1.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0042] FIG. 1 shows a metal pin according to the disclosure with a gold coating.

[0043] FIG. 2 shows a feedthrough for an igniter having a metal pin with a gold coating.

[0044] FIG. 3 shows a feedthrough for an igniter having a round metal pin with a gold coating in 3-dimensional view.

[0045] FIG. 4 shows a plot of the thickness of the gold coating along the length L of the metal pin.

DETAILED DESCRIPTION OF THE DISCLOSURE

[0046] FIG. 1 shows, by way of example, a contact pin with a gold coating 220, such as is used in an igniter, in particular in a feedthrough for an igniter in accordance with the disclosure. In the embodiment depicted in FIG. 1, the contact pin 1 comprises, by way of example, three regions: a first, essentially straight region, which is labeled with the reference number 3, a curved region, which is labeled with the reference number 5, and an end region or end section, which is labeled with the reference number 7. The end sections 10.1, 10.2 of the pin 1 are rounded by way of non-material-removing and/or material-removing methods, for example, whereby the radius R of the rounding is predetermined. The end section 10.1 is the contact end of the metal pin at a tripping unit of an igniter. The radius R of the rounding can be 0.5 mm and the diameter D of the contact pin can be 1 mm, for example. By way of non-material-removing and/or material-removing methods, it is possible to adjust a predetermined radius that is preferably half of the diameter of the cylindrical part of the contact pin. The section 200 that is furnished with the gold layer 220 with a thickness of 0.5-0.65 μm is part of the end section 7 of the metal pin. The gold layer 220 with a thickness of 0.5-0.65 μm represents, in the plateau region, the contact surface to other electrical devices, such as, for example, plug connectors. The length L of the section 200 of the end section 7, which receives the gold layer 220 with a thickness of 0.5-0.65 μm, is labeled with L. The length L of the section 200 of the metal pin is preferably 7 to 12 mm. The region 220 that is coated with the gold layer begins preferably at a distance of 1 mm to 4 mm from the contact end, which, in the present case, corresponds to the end section 10.1. The plateau portion of the region 220 has a length P. A profile of the metal pin as a function of the length L of the section 200, which also shows the plateau region, is depicted in FIG. 4. The contact pins or metal pins are obtained by cutting from a portion of wire. The non-straight, that is, curved section 5 of the pin is inclined at angle of 45° with respect to the straight region 3 and the end section 7. The diameter D of the pin is, for example, between 0.5 and 2.5 mm. Pins with diameters smaller than 0.5 mm are possible. FIG. 1 is essentially a basic principle and schematic view. In contrast to this, FIG. 3 shows an embodiment of a metal pin such as is realized at the present time. Depicted in FIG. 2 is the use of a contact pin according to the disclosure, in particular a metal pin, in a feedthrough for an igniter of a passenger protection device. FIG. 2 shows a feedthrough 100, in particular a metal sealing-material feedthrough for devices that are subject to high pressures, such as, for example, airbags or seatbelt tensioners as well as, in general, passenger protection devices.

[0047] Clearly seen is the feedthrough 100, comprising a ring-shaped element 106 with an opening. Further shown is a relief region 105. Punched out of the residual material of the ring-shaped element 106 with the thickness DR is a through-opening 20, which, in the present case, has a conical course 300. Whereas, in the exemplary embodiment shown, the conicity is introduced over the entire length of the through-opening, it is possible in an alternative embodiment for the conicity to extend only over a part of the length of the through-opening; that is, the feedthrough opening then has two sections, a conical section and a non-conical section adjoining it. The conical section can then be produced, for example, by reshaping or forming and the non-conical section can be produced by punching.

[0048] The ring-shaped or plate-shaped element 106 serves as a base for a metal sealing-material feedthrough with a total of two contact pins 50, 52 with a coating in accordance with the disclosure. In accordance with the disclosure, both the contact pin 50 and the contact pin 52 are, as depicted in FIG. 3, coated at least over a part of the length L at least with gold (Au) for better contacting. The coating of the pins 50, 52 is not explicitly depicted in FIG. 2 in contrast to FIG. 1. Whereas the contact pin, which is preferably a metal pin 50, is passed through a sealing material 60, which, in this case, is a glass material, but which can also be a glass ceramic material or a ceramic material, from the front side to the back side in a manner that is insulated with respect to the ring-shaped or plate-shaped base body 106, the second contact pin, in particular, the metal pin 52, serves as a ground pin. The ground pin can also be gold-coated.

[0049] As a ground pin, the second metal pin 52 is connected directly to the ring-shaped or plate-shaped element 106. Both the contact pin, in particular the metal pin 50, and the contact pin, in particular the metal pin 52, are curved in design. The curve in the conical metal pins is marked 54 or 56 and is clearly seen.

[0050] The contact pin, in particular the metal pin 50, can additionally be furnished with means 62 at the metal pin 50 itself that engages in the glass plug connector and thereby prevents the metal pin from being pressed out of the glass plug connector 60, in which the metal pin is glazed, even at high pressures.

[0051] The glazing of the contact pins, in particular the metal pin 50, into the sealing material 60 is conducted by fusion. Once the contact pin, in particular the metal pin, is fused in the sealing material 60, the glass plug connector together with the metal pin is introduced in the feedthrough opening 20. Subsequently, the glass plug connector together with the ring-shaped or plate-shaped element, that is, the base body, is heated, so that, after cooling, the metal of the ring-shaped or plate-shaped element shrinks onto the sealing material—in this case, the glass material—just like previously during the production of the glass plug connector, in which the contact pin, in particular the metal pin, is introduced in the glass plug connector. In this way, a pressure glazing with a tightness of 1.Math.10.sup.−8 mbar l/s at 1 bar pressure difference is provided. The contact pin serving as ground, in particular the metal pin 52, is connected to the plate-shaped element in a conductive manner by hard soldering. The soldering site is marked 70. All related metal pins are rounded at the end sections 72 by material-removing and/or material non-removing methods. In this way, no impurities are present on the surface of the contact pins, in particular the metal pins, so that the contact pins can be furnished with a coating, such as, for example, gold or also nickel, without any defects.

[0052] FIG. 3 shows a feedthrough 100 for an igniter in a three-dimensional view. Components identical to those in FIG. 2 are labeled with the same reference numbers. In contrast to FIG. 2, what is involved in FIG. 3 is not a schematic view, but rather a view of a specifically implemented exemplary embodiment. As in FIG. 2, the round-shaped and plate-shaped element 106 comprises two contact pins 50, 52, whereby, in contrast to FIG. 2, the contact pins 50, 52 are shown with a coating. Clearly seen is the coated section 220 of the metal pin. Components identical to those in FIG. 1 are marked with the same reference numbers. The plateau portion of the region 220 is marked with P as in FIG. 1. The dimensions are chosen as in the description in regard to FIG. 1. Likewise clearly seen in FIG. 3 is that, on the one hand, the coated metal pin 50 is passed through an opening of the base body 100 into a glass or glass ceramic material 20 and, on the other hand, the metal pin 52 is permanently connected with the base body by soldering, for example, and serves as the metal pin.

[0053] The contact pins coated in accordance with the disclosure have a low contact resistance and a good electrical conductivity. Because defects are prevented, it is possible to obtain a coating with gold (Au) in accordance with the disclosure in the section 200 of the end section of the metal pin 7 with a continuous surface that is largely free of defects. Alternatively to a direct coating of the metal pin with gold (Au), the metal pin can, first of all, be coated with nickel (Ni) as an adhesive layer and, subsequently, gold can be coated on the Ni layer in accordance with the coating profile for coatings of the prior art shown in FIG. 4 and in accordance with the disclosure. The plateau region 2300 of the coating has a length P and is depicted in FIG. 3. It is preferred when the nickel is applied by diffusion to the pin body prior to application of the gold layer. The diffused Ni layer results, on the one hand, in an increase in the adhesion of the gold layer and, on the other hand, also increased corrosion resistance, in particular of the coated pin.

[0054] The continuous surface of the coating ensures, in turn, that any corrosion can be largely excluded. The plateau region of the coating in accordance with the disclosure, which is marked with 2300, begins at a distance of 1 mm to 4 mm following the contact end or the end section 10.1 of the metal pin and extends over a length P of up to 10 mm, so that the plateau region 2300 ends at a distance of 2 mm to 8 mm from the end section 10.1, that is, from the tip of the metal pin. The maximum layer thickness of the gold coating in the plateau region with the length P lies between 0.2 μm and 0.8 μm, in particular between 0.4 μm and 0.7 μm. Outside of the plateau region towards the contact end 10.1, the layer thickness is only 0.05 μm to 0.20 μm. The application of the gold layer can be conducted in a gold-plating unit by using a selective brush technique, for example, with high selectivity.

[0055] The plot of the gold coating along the length L of the metal pin as a function of the distance from the end section or contact end 10.1, that is, the tip of the metal pin, is depicted in FIG. 4.

[0056] In FIG. 4, the thickness plots of the profile of the gold coating of two metal pins according to the prior art are marked 2000.1 and 2000.2, and the plot according to the disclosure is marked 2200.

[0057] The first profile 2000.1 in accordance with the prior art has, in the region of the tip of the metal pin, as shown in FIG. 4, a very great thickness of 0.75 to 0.65 μm. In the region of the plateau, which serves for contacting, the layer thickness decreases too rapidly and too intensely for the profile 2000.1 in accordance with the prior art, so that a secure contacting of a plug connector, for example, is not possible. This is due to the fact that, for the profile 2000.1 in the region of 3 mm to 6 mm distance from the tip of the metal pin, the layer thickness is only 0.3 μm, so that no adequately thick gold layer for a contacting is provided.

[0058] Although the second profile 2000.2 in accordance with the prior art shows in the plateau region from 3 mm to 6 mm an adequate thickness, so that a secure contacting is provided, the gold layer at a slight distance from the tip or at the tip is unnecessarily thick at 0.75 μm. In contrast to the prior art, the profile 2200 according to the disclosure shows, in the form of the profile 2000.2, similarly good properties in regard to the contacting, but, for this purpose, markedly less material is necessary than for the profile 2000.2 in accordance with the prior art.

[0059] As can be seen, in the plot 2200 at the contact end 10.1, that is, at the tip of the contact pin or the metal pin, the layer thickness of the coating of the disclosure for the solution in accordance with the disclosure is only 0.1 μm and increases in a largely linear manner up to a distance of 3 mm from the tip to more than 0.6 μm.

[0060] The plateau region 2300 with the length P in the plot 2200 of the metal coating in accordance with the disclosure is the contact region of the contact pin or metal pin with a plug connector, for example. In the contact region, other electrical components, such as, for example, plug connectors, are connected to the metal pin in an electrically conductive manner. On account of the relatively thick gold coating with a thickness of approximately 0.65 μm in the plateau region 2300, a very reliable connection of the metal pin to other electrical devices is made possible with low contact resistance. The plateau region 2300 in the plot 2200 of the coating is produced very selectively in accordance with the disclosure, in the region 3 mm to 6 mm from the tip of the metal pin, for example by masking in the gold-plating unit. In the plateau region, the gold coating has a largely constant thickness of 0.6 μm to 0.65 μm. The selective application of the gold layer, in particular in the plateau region 2300 of the plot 2200, is conducted preferably in a galvanic manner. After the plateau region 2300, the layer thickness decreases largely linearly, so that, after a length of 9 mm, a coating is no longer present.

[0061] In contrast to the prior art with the plot 2000.1, which, at the beginning of the pin, that is, in the contact end 10.1, has a layer thickness of more than 0.75 μm, it is possible by way of masking in the gold coating unit to produce a nearly rectangular plot of the coating, so that only the contact region of the metal pin is coated selectively in accordance with layer plot 2200, and this also results in significant material savings in comparison to the profile 2000.2 in accordance with the prior art.

[0062] Accordingly, the disclosure provides a contact pin or metal pin and a passenger protection device igniter having a contact pin or metal pin of this kind, which provide a geometrically defined connection region with a coating, in particular at least an Au coating, in particular for insertion into a plug connector system. Usually, the metal pin according to the disclosure is pushed into a plug connector. The latter has contact surfaces that are distant from the end of the contact pin or metal pin. The maximum layer thickness of the gold layer is present, in accordance with the disclosure, in the region of the contact surfaces. This makes possible a secure, that is, long-term stable contacting, which has a low contact resistance. In contrast to this, the layer thickness of the gold layer decreases towards the contact end or end section and is thinner there and, as a result, the contact resistance is higher there and the probability of corrosion is greater.