Gold-based brazing filler metal, manufacturing method of gold-based brazing filler metal, manufacturing method of feedthrough device and active implantation instrument

Abstract

The invention discloses gold-based brazing filler metal and a manufacturing method thereof, a feedthrough device manufacturing method and an active implantation instrument. The gold-based brazing filler metal comprises the following components in percentage by mass: 2.0-10.0% of silicon, 2.0-10.0% of copper, 2.0-10.0% of nickel, 2.0-10.0% of nickel, 2.0-10.0% of nickel and the balance of copper. 0.5 to 5.0 percent of indium; 85.0%-97.5% of gold; the balance is impurities. Gold-based brazing filler metal can be inserted between each metal contact of the feed-through device and the ceramic plate for brazing, gold-based brazing filler metal can be inserted between the periphery of the ceramic plate and the flange for brazing, high-purity gold is used as a base material in the gold-based brazing filler metal, high-purity silicon is added, gold-silicon alloy is formed, the melting point of the gold-based brazing filler metal does not exceed 600 DEG C, and the service life of the feed-through device is prolonged. In this way, the melting point of the gold-based brazing filler metal is obviously lower than that of base metal such as the ceramic plate, the metal contact and the flange, even if the thickness of the flange is small, deformation of the flange or cracking of the ceramic plate can be avoided during brazing, and the feedthrough device with the long and narrow ceramic plate can be manufactured; in addition, the high-purity indium element is added into the gold-based brazing filler metal, and the binding force between the gold-based brazing filler metal and a ceramic plate can be increased after brazing by means of the wettability of the indium element to ceramic.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of brazing, and particularly relates to a gold-based brazing filler metal, a manufacturing method thereof, a feedthrough manufacturing method and an active implantable instrument. BACKGROUND

[0002] In an active implantable medical instrument, a feedthrough is one of the common components, which functions as an exchange medium of internal and external signals. The feedthrough comprises a ceramic body, metal contact pins and a shell. A plurality of through holes are distributed on the upper and lower surfaces of the ceramic plate, and the metal contact pins penetrate through the through holes. The metal contact pins are insulated from each other by the ceramic plate. The shell is made of metal material and is arranged outside the ceramic body to provide support for the entire feedthrough and facilitate subsequent packaging. When the ceramic body, the metal contact pins and the shell are welded together, since the welding involves dissimilar materials, and the melting point of the ceramic is generally very high, common welding processes such as laser welding, resistance welding and ultrasonic welding are not applicable.

[0003] Brazing is an important welding process for medical instruments, which refers to a method of using a metal material with a lower melting point than the base material as a filler metal, heating the welding parts and the filler metal to a temperature higher than the melting point of the filler metal and lower than the melting temperature of the base material, and using the liquid filler metal to wet the base material, fill the gap between the joints and diffuse with the base material to realize the connection of the welding parts. Brazing is commonly used in dental, orthopedic and other instruments. Considering the biological requirements of the implant, materials such as copper-based and silver-based are abandoned, and the existing brazing filler metal is generally pure gold. Since the melting point of pure gold is high, the shell is designed to be thin as an implantable instrument. If the brazing temperature is too high, it can cause the hardness to decrease and bring residual stress, resulting in deformation of the instrument or cracking of the ceramic plate. SUMMARY

[0004] The purpose of the present application is to provide a gold-based brazing filler metal, a manufacturing method thereof, a feedthrough manufacturing method and an active implantable instrument.

[0005] The first aspect of the present application provides a gold-based brazing filler metal for brazing between a ceramic and a metal in an active implantable instrument, the gold-based brazing filler metal comprising the following components in mass percentage:

[0006] Silicon 2.0-10.0%; Indium 0.5-5.0%; Gold 85.0-97.5%; and the balance being impurities.

[0007] Further, the content of indium is 1.0-4.0% in mass percentage; and the content of silicon is 2.5-5% in mass percentage.

[0008] Further, the purity of the gold is above 98%; and preferably, the purity of the gold is above 99%;

[0009] The purity of the silicon is above 99%; and preferably, the purity of the silicon is above 99.9%;

[0010] The purity of the indium is 99% or more; preferably, the purity of the indium is 99.9% or more.

[0011] Further, the gold-based filler material is made in any one of a sheet shape, a ring shape, a long strip shape, or a conical cylinder shape.

[0012] The melting point of the gold-based filler material is 350-600℃.

[0013] The second aspect of the present application provides a gold-based filler material manufacturing method for brazing between ceramics and metals in active implant devices, comprising:

[0014] The gold raw material is made into a gold foil, the indium raw material is made into an indium foil, and the silicon raw material is made into a silicon powder;

[0015] Each raw material is weighed according to a preset mass percentage;

[0016] The gold foil is folded into multiple layers according to a preset length, and the silicon powder is applied to the surface of each layer of gold foil to obtain a gold-silicon mixture;

[0017] The indium foil is folded and laid in a crucible, the gold-silicon mixture is then put into the crucible, and the crucible is sent into an induction furnace;

[0018] The heating system of the induction furnace is turned on, the temperature rising speed is set to 10-20℃ / min, when the temperature reaches 1064-1264℃, the temperature is kept for 10-60min;

[0019] The electromagnetic stirring is turned on for 2-5min, and the temperature is kept for 10-60min again;

[0020] The heating system is turned off, the cooling device of the induction furnace is turned on for cooling, and the furnace temperature is cooled to room temperature to obtain a formed block-shaped filler material.

[0021] Further, the gold-based filler material manufacturing method further comprises: the induction furnace is first in a vacuum state to 10 -4 Pa, and then inert gas is filled.

[0022] Further, the gold-based filler material manufacturing method further comprises:

[0023] The formed block-shaped filler material is subjected to rolling and thinning treatment by a multi-roller mill to obtain a preformed body with a set thickness; wherein the set thickness of the preformed body is 0.03-0.5mm.

[0024] Further, the gold-based filler material manufacturing method further comprises:

[0025] The deformation of the multi-roller mill is set to 0.03-0.2 mm / revolution, and the formed block-shaped filler metal is rolled by the multi-roller mill until the thickness of the filler metal becomes the first threshold value;

[0026] The filler metal with the thickness of the first threshold value is placed in an induction furnace for annealing after being vacuumized and heated to 190-220 DEG C;

[0027] The annealed filler metal is rolled again by the multi-roller mill until the thickness of the filler metal becomes the second threshold value;

[0028] The filler metal is repeatedly annealed and rolled until the filler metal becomes a preformed body with a set thickness.

[0029] The third aspect of the present application provides a method for preparing a gold-based filler metal for brazing between ceramics and metals in active implant devices, the gold-based filler metal comprising a gold-silicon alloy layer and an indium layer in contact with each other; the method comprising:

[0030] The raw materials are weighed according to a preset mass percentage;

[0031] The gold raw material and the silicon raw material are smelted to obtain a formed block-shaped gold-silicon alloy body;

[0032] The formed block-shaped gold-silicon alloy body is rolled by a multi-roller mill for thinning to obtain a gold-silicon alloy layer with a set thickness;

[0033] The gold-silicon alloy layer is subjected to an indium layer electroplating treatment to obtain the gold-based filler metal; wherein the electrolyte mainly comprises indium sulfate as a main salt, and citric acid is added as a complexing agent to stabilize In 3+ , and the pH is controlled at 2-4.

[0034] The fourth aspect of the present application provides a method for preparing a feedthrough for active implant devices, the gold-based filler metal or the gold-based filler metal prepared by the method is used, the feedthrough comprises a ceramic plate, a metal contact and a flange, the ceramic plate is provided with a plurality of through holes distributed at intervals, the metal contact penetrates the through hole, the flange is provided with a groove, the ceramic plate is embedded in the groove, and a gap is formed between the periphery of the ceramic plate and the flange; the method for preparing the feedthrough comprises:

[0035] The strip-shaped gold-based filler metal is embedded in the gap;

[0036] The conical cylindrical gold-based filler metal is sleeved on the metal contact and inserted into the through hole, so that the conical cylindrical gold-based filler metal is located between the metal contact and the ceramic plate;

[0037] The assembled feedthrough is installed on a tooling and placed in an induction furnace;

[0038] Turning on the heating system of the induction furnace, setting the heating rate to 5-25℃ / min, when the temperature reaches the set threshold, keeping warm for 10-60min; wherein the set threshold is 20-100℃ higher than the melting point of the gold-based filler metal;

[0039] Turning off the heating system, cooling with the furnace, and obtaining the brazed feedthrough when the furnace temperature cools to room temperature.

[0040] The fifth aspect of the present application provides an active implant device comprising the feedthrough prepared by the feedthrough manufacturing method.

[0041] The above technical solutions of the present application have the following beneficial technical effects:

[0042] 1. In the embodiments of the present application, gold-based filler metal can be inserted between each metal contact and the ceramic plate of the feedthrough for brazing, and gold-based filler metal can be inserted between the periphery of the ceramic plate and the flange for brazing. The gold-based filler metal has high-purity gold as the base material and adds high-purity silicon to form a gold-silicon alloy, so that the melting point of the gold-based filler metal does not exceed 600℃. Thus, the melting point of the gold-based filler metal is significantly lower than the melting points of the ceramic plate, the metal contact, and the flange, the parent material. Even if the thickness of the flange is thin, deformation of the flange or cracking of the ceramic plate can be avoided during brazing. Furthermore, by adding high-purity indium elements to the gold-based filler metal, the wettability of the ceramic can be utilized, and the bonding force between the gold-based filler metal and the ceramic plate can be increased after brazing. Further, through impact experiments on the feedthrough product, it is detected that the air tightness is qualified, there is no obvious filler metal falling under the microscope, the bonding force between the gold-based filler metal and the parent material is good, and the impact resistance is high.

[0043] 2. In the embodiments of the present application, low-temperature brazing with gold-based filler metal can be applied to feedthroughs with long and narrow ceramic plates. The brazing has a low melting point temperature, which can ensure the flatness of the parent material after brazing, produce less welding internal stress, and can withstand subsequent impact tests, and has high impact resistance. BRIEF DESCRIPTION OF DRAWINGS

[0044] Figure 1 is a structural schematic diagram of a feedthrough according to the first embodiment of the present application;

[0045] Figure 2 is a partial enlarged schematic view of A of Figure 1

[0046] Figure 3 is a structural schematic diagram of a feedthrough according to the second embodiment of the present application;

[0047] Figure 4 is a structural schematic diagram of a feedthrough mounted on a tooling according to the third embodiment of the present application;

[0048] Figure 5 ​4 is a schematic structural diagram of a feedthrough according to a fourth embodiment of the present application. DETAILED DESCRIPTION

[0049] In order to make the purpose, technical solutions and advantages of the present application clearer, the present application is further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings. It should be understood that these descriptions are merely exemplary and are not intended to limit the scope of the present application. In addition, in the following description, descriptions of well-known structures and technologies are omitted to avoid unnecessary confusion in the concepts of the present application. In this article, terms such as first, second, and third are only used to distinguish one feature from another, and do not require or imply any order or association between these features.

[0050] Feedthroughs are common components in active implantable medical devices, serving as a medium for communicating internal and external signals. These feedthroughs consist of a ceramic body, metal contact pins, and a housing. The ceramic plate has several through-holes on its upper and lower surfaces, through which the metal contact pins extend. The metal contact pins are insulated from each other by the ceramic plate. The housing is made of metal and positioned outside the ceramic body, providing support for the entire feedthrough and facilitating subsequent packaging. When welding the ceramic body, metal contact pins, and housing together, common welding processes such as laser welding, resistance welding, and ultrasonic welding are not suitable due to the high melting point of ceramics and the dissimilar materials involved.

[0051] In the related art, the following two methods are mainly used to connect the components of the feedthrough:

[0052] (1) Brazing method using pure gold as solder

[0053] Brazing is an important welding process for medical devices. It refers to a method of using a metal material with a lower melting point than the base material as a brazing filler metal, heating the weldment and the brazing filler metal to a temperature above the melting point of the brazing filler metal and below the melting temperature of the base material, and using the liquid brazing filler metal to wet the base material, fill the joint gap, and diffuse with the base material to achieve the connection of the weldment. Brazing is commonly used in dental and orthopedic devices. Considering the biological requirements of the implant, copper-based and silver-based materials are abandoned. Existing brazing fillers are generally pure gold. Since the melting point of pure gold is 1064°C, pure gold has a high melting point. In order to ensure that the solder is fully melted and has good fluidity, the brazing temperature will be 20-100°C higher than the melting point of the solder. When the base material to be welded is, for example, pure titanium and TC4 (Ti-6Al-4V, a typical medical titanium alloy), its melting point is around 1668°C, and the melting point of MP35N (35Co-35Ni-20Cr-10Mo) is 1440°C. If the gap between the melting point of the base material and the brazing temperature is not large enough, there will be the following disadvantages and hidden dangers:

[0054] As an implantable device, the housing is designed to be thin. Excessively high brazing temperatures can reduce its hardness and introduce residual stress, leading to device deformation or cracking of the ceramic plate. This not only affects its support function but also complicates subsequent packaging. Higher temperatures can also cause intergranular corrosion of the parent material, impacting its mechanical and electrical properties. They can even induce the precipitation of harmful elements, such as aluminum and vanadium in TC4 and nickel and chromium in MP35N, which can directly pose biological hazards.

[0055] Furthermore, during impact testing, the product failed to meet airtightness standards. Microscopic analysis revealed obvious solder detachment, indicating that the use of pure gold as solder in brazing technology results in a weak bond between the solder and the base material, resulting in poor impact resistance.

[0056] (2) Adhesion using glue

[0057] To connect ceramics to other materials while avoiding the risks associated with high temperatures, bonding is a potential solution. Epoxy adhesive EB-0107LP-1 is a long-term implantable adhesive. The specific method involves mixing components A and B in the correct proportions and stirring thoroughly. Using a dispenser, the adhesive is injected into the gaps between the ceramic plate's through-holes and metal contacts, and between the ceramic plate's sides and the flange / housing. The adhesive is then placed in a 65°C thermostat for one hour. This results in a feedthrough with a secure connection and acceptable airtightness.

[0058] The disadvantage of the feedthrough produced by this technology is that it has poor durability and cannot be used for long-term implantation. For example, an accelerated aging test can be performed to verify the airtightness change of the feedthrough. The airtightness qualification standard is ≤5×10 -9 atm·mL / s. All samples passed the test before aging. The aging temperature and humidity were 60°C / 60%, respectively. The planned test durations were 3 days, 1 week, and 2 weeks. Results showed that some products failed the airtightness test after 3 days, and all failed after 1 week.

[0059] According to the Arrhenius formula (AAF = Q10[(TAA - TRT) / 10]), using the generally conservative method for calculating the aging factor, Q10 is set to 2. Substituting TAA = 60°C and TRT = 25°C, we obtain AAF = Q10[(TAA - TRT) / 10] = 2(3.5) ≈ 11.3. This indicates that the bonded feedthrough will experience airtight failure after just over 30 days, clearly not meeting the requirements for long-term implantation.

[0060] Based on this, an embodiment of the present application provides a gold-based solder for brazing ceramics and metals in active implantable devices. The gold-based solder includes the following components in percentage by mass:

[0061] Silicon 2.0-10.0%; Indium 0.5-5.0%; Gold 85.0-97.5%; the remainder is impurities.

[0062] In the embodiments of the present application, the active implanted device comprises a feedthrough 10, which may, for example, comprise a ceramic plate 11, metal contacts 12 and a flange 13. The ceramic plate 11 is provided with a plurality of through holes 14 distributed at intervals, the metal contacts 12 are inserted through the through holes 14, and the flange 13 is provided with a groove 15 in which the ceramic plate 11 is embedded, and a gap is formed between the periphery of the ceramic plate 11 and the flange 13. The material of the ceramic plate 11 may, for example, be medical-grade alumina, zirconia or sapphire. The metal contacts 12 may, for example, comprise niobium, platinum-iridium or MP35N, which are biologically excellent materials. The flange 13 may, for example, be titanium or a titanium alloy, and the thickness of the flange 13 may, for example, be 0.2-0.5 mm. As shown in FIG. 1, each metal contact 12 and the ceramic plate 11 may be inserted with a gold-based brazing filler metal for brazing, and the periphery of the ceramic plate 11 and the flange 13 may be inserted with a gold-based brazing filler metal for brazing. The gold-based brazing filler metal has high-purity gold as a base material and is added with high-purity silicon to form a gold-silicon alloy, so that the melting point of the gold-based brazing filler metal is not higher than 600°C. In this way, the melting point of the gold-based brazing filler metal is significantly lower than the melting points of the base materials of the ceramic plate 11, the metal contacts 12 and the flange 13, so that even if the thickness of the flange 13 is relatively small, deformation of the flange 13 or cracking of the ceramic plate 11 can be avoided. Furthermore, the gold-based brazing filler metal is added with high-purity indium, which can be used to wet the ceramic, so that the bonding force between the brazing filler metal and the ceramic plate 11 can be increased after brazing. Figures 1-5

[0063] In some embodiments, the content of indium is 1.0-4.0% by mass percentage, and the content of silicon is 2.5-5% by mass percentage. When the content of silicon is 2.5-5% by mass percentage, the melting point of the gold-based brazing filler metal can reach 350-600°C, so that the brazing temperature can be more easily controlled, and adverse conditions such as deformation of the base material or precipitation of toxic elements contained in the base material can be prevented. For example, when the content of indium is 1.45% by mass percentage, and especially when the gold-based brazing filler metal comprises a gold-silicon alloy layer and an indium layer, i.e., the indium layer is arranged on one surface of the gold-silicon alloy layer and is attached to the ceramic plate 11, the ceramic plate 11 can obtain more direct and sufficient wetting effect during brazing, so that the bonding force between the brazing filler metal and the ceramic plate 11 can be stronger.

[0064] ​In some embodiments, the gold has a purity of 98% or greater; preferably, the gold has a purity of 99% or greater; the silicon has a purity of 99% or greater; preferably, the silicon has a purity of 99.9% or greater; the indium has a purity of 99% or greater; preferably, the indium has a purity of 99.9% or greater. This ensures that the raw materials used to make the gold-based solder are of high purity, avoiding unnecessary impurities that are harmful to the human body, and ensuring that the brazed feedthrough meets the requirements for long-term implantation.

[0065] In some embodiments, the gold-based solder is made into any one of a sheet, a ring, a strip, or a conical tube. For example, the gold-based solder can be made into a conical tube, and the conical tube-shaped gold-based solder 16 has a large end and a small end, and the outer diameter of the cone gradually shrinks from the large end to the small end. The conical tube-shaped gold-based solder can be configured to be adapted to the through hole 14 and the metal contact 12 respectively. When the conical tube-shaped gold-based solder 16 is inserted into the through hole 14, the conical tube-shaped gold-based solder 16 can be located between the metal contact 12 and the ceramic plate 11. This is conducive to accurate positioning of the gold-based solder during brazing. When the gold-based solder melts, it can effectively fill the gap between the metal contact 12 and the ceramic plate 11, thereby ensuring a firm weld. Similarly, a long strip of gold-based solder can be embedded in the gap between the four sides of the ceramic plate 11 and the flange 13, and the long strip of gold-based solder 17 is adapted to the size of the gap. When the gold-based solder melts during brazing, it can effectively fill the gap between the four sides of the ceramic plate 11 and the flange 13, thereby making the welding firm and preventing the gold-based solder from flowing to other places after melting and causing unnecessary waste, which can save costs.

[0066] In some embodiments, the ceramic plate 11 of the feedthrough is an elongated oval (i.e., waist-shaped) or triangular shape. The ceramic plate 11 of such a feedthrough has an aspect ratio greater than 4 and has small acute angles, which makes it more susceptible to high temperatures. When pure gold is brazed, the ceramic plate 11 is easily deformed or broken, making it almost impossible to complete the brazing. Figure 1 The length of the oval ceramic plate 11 is 18 mm and the width is 4 mm; Figure 5 As shown, the triangular ceramic plate 11 has a long right-angled side of 17 mm, a short right-angled side of 7 mm, and a minimum acute angle of 20°. When brazing with a gold-based solder, the low melting point ensures a smooth base metal after brazing, reduces weld internal stress, and withstands subsequent impact tests, demonstrating high impact resistance.

[0067] The present invention provides a method for preparing a gold-based brazing material for brazing ceramics and metals in active implantable devices, comprising the following specific steps:

[0068] S101: manufacturing gold raw materials into gold foil, manufacturing indium raw materials into indium foil, and manufacturing silicon raw materials into silicon powder;

[0069] S102: Weigh each raw material according to the preset percentage of quality;

[0070] S103: Fold the gold foil into multiple layers according to the preset length, and apply silicon powder to the surface of each layer of gold foil to obtain a gold-silicon mixture;

[0071] S104: Fold the indium foil and lay it in the crucible, then put the gold-silicon mixture into the crucible, and put the crucible into the induction furnace;

[0072] S106: Turn on the heating system of the induction furnace, set the temperature rising speed to 10-20℃ / min, when the temperature reaches 1064-1264℃, keep it for 10-60min;

[0073] S107: Turn on the electromagnetic stirring for 2-5min, and keep it for another 10-60min;

[0074] S108: Turn off the heating system and turn on the cooling device of the induction furnace to cool down, until the furnace temperature cools down to room temperature, to obtain the formed block-shaped filler metal.

[0075] Specifically, the crucible can be selected as a graphite crucible to avoid mixing of impurities that are harmful to human health during the smelting process of the raw materials; the induction furnace can be selected as a vacuum medium-frequency induction furnace, and the cooling device of the induction furnace can be set as a water cooling device to realize rapid cooling of the melted gold-based filler metal, prevent silicon phase from precipitating and reduce plasticity, so as to obtain the formed block-shaped filler metal; by folding the gold foil into multiple layers according to the preset length and applying silicon powder to the surface of each layer of gold foil, a uniformly mixed gold-silicon mixture is obtained; and by turning on the electromagnetic stirring, the raw materials can be stirred uniformly during the melting process. The temperature rising speed of the induction furnace is set to 10-20℃ / min to minimize the volatilization of silicon powder; after heating, the highest temperature is 1064-1264℃, and the temperature is kept for 10-60min, which can prevent insufficient melting caused by low temperature and short time, and crucible reaction caused by high temperature and long time; during the temperature keeping period, the electromagnetic stirring device is turned on to promote homogenization of the components and reduce segregation.

[0076] In some embodiments, the gold-based filler metal manufacturing method further includes the following specific steps:

[0077] S105: First, the induction furnace is evacuated to 10 -4 -10 Pa, and then inert gas is filled. The inert gas is, for example, argon or nitrogen. By first evacuating the induction furnace and then filling it with inert gas, the formation of SiO2 or SiC from trace amounts of oxygen or carbon and silicon is prevented, thereby avoiding a reduction in alloy performance.

[0078] In some embodiments, the gold-based filler metal manufacturing method further includes the following specific steps:

[0079] S109: rolling and thinning the formed blocky filler metal by a multi-roller mill to obtain a preformed body with a set thickness; wherein the set thickness of the preformed body is 0.03-0.5mm.

[0080] Specifically, the gold-based filler metal after smelting exists in the form of a block, and the thickness is uneven, which is not conducive to direct brazing. For example, the block can be rolled into a gold foil or ground into an alloy powder state. The formed blocky filler metal can be rolled and thinned by a multi-roller mill, for example, a double-roller mill. After rolling, the set thickness of the preformed body is 0.03-0.5mm; preferably, the set thickness of the preformed body is 0.03-0.3mm, and the preformed body is stamped into an adaptive shape according to the structure of the brazing position; when it is made into an alloy powder, it can be made into an alloy paste for convenience of prepositioning in the weld.

[0081] In some embodiments, step S109: rolling and thinning the formed blocky filler metal by a multi-roller mill to obtain a preformed body with a set thickness, comprises the following specific steps:

[0082] S1091: setting the deformation amount of the multi-roller mill to 0.03-0.2mm / pass, and rolling the formed blocky filler metal by the multi-roller mill until the thickness of the filler metal becomes a first threshold value;

[0083] S1092: placing the filler metal with a thickness of the first threshold value into an induction furnace, and annealing after vacuumizing and heating to 190-220℃;

[0084] S1093: rolling the annealed filler metal again by the multi-roller mill until the thickness of the filler metal becomes a second threshold value;

[0085] S1094: repeating annealing and rolling the filler metal until the filler metal becomes a preformed body with a set thickness.

[0086] Specifically, by repeatedly rolling and thinning the blocky filler metal by the multi-roller mill and annealing to eliminate stress, the overall rolled filler metal can be flat and avoid cracks.

[0087] The embodiment of the present application provides a gold-based filler metal manufacturing method for brazing between ceramics and metals in an active implant device, the gold-based filler metal comprising a gold-silicon alloy layer and an indium layer in contact with each other; the method comprises the following specific steps:

[0088] S201: weighing each raw material according to a preset mass percentage;

[0089] S202: smelting the gold raw material and the silicon raw material to obtain a formed blocky gold-silicon alloy body;

[0090] S203: the formed block-shaped gold-silicon alloy body is subjected to rolling thinning treatment by a multi-roller mill to obtain a gold-silicon alloy layer with a set thickness;

[0091] S204: the gold-silicon alloy layer is subjected to indium layer electroplating treatment to obtain the gold-based filler metal; wherein the electrolyte takes indium sulfate as a main salt and adds citric acid as a complexing agent to stabilize In 3+ , and the pH is controlled at 2-4.

[0092] Specifically, the gold raw material and the silicon raw material are first melted to obtain a formed block-shaped gold-silicon alloy body; the formed block-shaped gold-silicon alloy body is subjected to rolling thinning treatment by a double-roller mill to obtain a gold-silicon alloy layer with a set thickness; the thickness of the gold-silicon alloy layer is, for example, 0.03-0.5 mm; and then an indium layer is electroplated on one surface of the gold-silicon alloy layer, and the indium layer is tightly attached to the ceramic plate 11, so as to increase the concentration of indium at the contact with the ceramic plate 11, so that the ceramic plate 11 can obtain a more direct and sufficient wetting effect during brazing, so that the bonding force between the filler metal and the ceramic plate 11 is stronger. The thickness of the electroplated indium layer can be controlled by controlling the electrolysis time, so as to control the indium content in the gold-based filler metal to be 0.50-1.45% by mass.

[0093] In some embodiments, step S202: the gold raw material and the silicon raw material are melted to obtain a formed block-shaped gold-silicon alloy body, includes the following specific steps:

[0094] S2021: the gold raw material is made into gold foil, and the silicon raw material is made into silicon powder;

[0095] S2022: the gold foil is folded into multiple layers according to a preset length, and the silicon powder is applied to the surface of each layer of gold foil to obtain a gold-silicon mixture;

[0096] S2023: the gold-silicon mixture is placed in a crucible, and the crucible is sent into an induction furnace;

[0097] S2024: the heating system of the induction furnace is turned on, the temperature rising speed is set to 10-20 ℃ / min, when the temperature reaches 1100-1250 ℃, the temperature is kept for 10-20 min;

[0098] S2025: the electromagnetic stirring is turned on for 2-5 min, and the temperature is kept for another 30 min;

[0099] S2026: the heating system is turned off, water cooling is performed, and the furnace temperature is cooled to room temperature to obtain a formed block-shaped gold-silicon alloy body.

[0100] The embodiment of the application provides a feedthrough manufacturing method for an active implant device, and adopts the gold-based filler or the gold-based filler prepared by the method, and the feedthrough comprises a ceramic plate 11, a metal contact 12 and a flange 13, the ceramic plate 11 is provided with a plurality of through holes 14 distributed at intervals, the metal contact 12 penetrates the through holes 14, the flange 13 is provided with a groove 15, the ceramic plate 11 is embedded in the groove 15, and a gap is formed between the periphery of the ceramic plate 11 and the flange 13; and the feedthrough manufacturing method comprises the following specific steps:

[0101] S301: embedding the long-strip-shaped gold-based filler 17 into the gap;

[0102] S302: sleeving the conical-cylinder-shaped gold-based filler sleeve 16 on the metal contact 12 and inserting the gold-based filler sleeve 16 into the through hole 14, so that the conical-cylinder-shaped gold-based filler is located between the metal contact 12 and the ceramic plate 11;

[0103] S303: installing the assembled feedthrough 10 on a tool 20 and placing the tool 20 into an induction furnace;

[0104] S304: starting a heating system of the induction furnace, setting a temperature rising speed to be 5-25 DEG C / min, when the temperature reaches a set threshold value, keeping warm for 10-60 min; wherein the set threshold value is 20-100 DEG C higher than the melting point of the gold-based filler;

[0105] S305: closing the heating system, cooling with the furnace, and obtaining a brazed feedthrough when the furnace temperature is cooled to room temperature.

[0106] Specifically, the conical gold-based solder 16 is put on the metal contact 12 and inserted into the through hole 14 to achieve the positioning of the gold-based solder and the metal contact 12, and the matching long strip of gold-based solder 17 is embedded in the gap between the four sides of the ceramic plate 11 and the flange 13. The assembled feedthrough is installed on the tooling and placed in the induction furnace for brazing. The gold-based solder uses high-purity gold as the base material and adds high-purity silicon to form a gold-silicon alloy, which can make the melting point of the gold-based solder not exceed 600°C, and the set threshold reached after the induction furnace is heated can not exceed Over 700°C; the gold-based solder melts in the induction furnace and cools with the furnace. When the furnace temperature cools to room temperature, a brazed feedthrough can be obtained, which is easy to operate. In this way, the highest temperature in the induction furnace is significantly lower than the melting point of the base materials such as the ceramic plate 11, the metal contact 12 and the flange 13. Even if the thickness of the flange 13 is relatively thin, deformation of the flange 13 or cracking of the ceramic plate 11 can be avoided. In addition, high-purity indium elements are added to the gold-based solder. The wettability of indium elements to ceramics can be utilized to increase the bonding strength between the solder and the ceramic plate 11 after brazing. Furthermore, by performing an impact test on the brazed feedthrough product, the air tightness is qualified after testing, and no obvious solder shedding is observed under a microscope. The bonding strength between the gold-based solder and the base material is good and the impact resistance is high. In addition, the raw materials for making the gold-based solder are of high purity and contain few impurities, which meets the requirements of long-term implantation.

[0107] An embodiment of the present application provides an active implantable device, including a feedthrough manufactured by the above-mentioned feedthrough manufacturing method.

[0108] The present invention will be described in further detail below in conjunction with the examples. The following examples are used to illustrate the present invention but are not intended to limit the scope of the present invention.

[0109] Example 1

[0110] (1) Prepare the raw materials according to the following requirements:

[0111] Gold foil with a purity of 99.99%, specifications are W20mm×T0.05mm, and the mass is 50.0g; silicon powder with a purity of 99.999%, specifications are 500 mesh, and the mass is 2.00g; indium foil with a purity of 99.999%, specifications are W10mm×T0.05mm, and the mass is 1.00g.

[0112] (2) Solder melting

[0113] A vacuum medium frequency induction furnace is used to melt the prepared raw materials. The configuration parameters of the induction furnace are: the maximum vacuum degree is 10 -5 Pa level, maximum temperature about 1500 ℃, equipped with electromagnetic stirring device and rapid water cooling device, etc., 99.999% high purity argon. The gold-based solder melting process includes the following steps:

[0114] 1) Unfold the gold foil, and apply silicon powder to the surface of the gold foil within 3cm from one end. Fold the gold foil and apply silicon powder again. Repeat the above steps to fold the gold foil into multiple layers, so that gold and silicon are mixed evenly;

[0115] 2) Fold the indium foil on the bottom of the graphite crucible, and then put the gold-silicon mixture into the crucible. Finally, put the crucible into the induction furnace;

[0116] 3) Vacuumize to 10 -4 Pa, and then stop the vacuum pump and fill high-purity argon;

[0117] 4) Slightly open the exhaust valve, and adjust the gas flow to ensure that the argon pressure in the tube cavity is about 1kPa;

[0118] 5) Set the heating rate to 15℃ / min, and heat to the highest temperature of 1200℃, and keep the temperature for 10min. Open the electromagnetic stirring for 2min to promote the homogenization of the components, and keep the temperature for another 30min, and then stop the heating system.

[0119] 6) Open the water cooling to quickly cool the furnace temperature to 100℃, and stop the argon. When the furnace temperature cools to room temperature, open the furnace cavity, and take out the cooled and shaped block-shaped filler metal.

[0120] (Three) Filler metal shaping

[0121] The block-shaped filler metal cooled and shaped after smelting is irregular block-shaped, with a thickness of 2-5mm, which needs to be rolled and thinned to facilitate the brazing shaping operation. The shaping process of the gold-based filler metal includes the following steps:

[0122] 1) Set the deformation of the double-roller rolling machine to 0.1mm / pass, until the thickness of the filler metal is rolled to 1mm, and the whole is flat and crack-free. Put the filler metal into the vacuum induction furnace, heat to 200℃ under the vacuum degree of 10 -3 Pa for 20min, and take it out for use;

[0123] 2) Set the deformation of the double-roller rolling machine to 0.08mm / pass, until the thickness of the filler metal is rolled to 0.2mm. Put the filler metal into the vacuum induction furnace again, heat to 200℃ under the vacuum degree of 10 -3 Pa for 20min, and take it out for use;

[0124] 3) Set the deformation of the double-roller rolling machine to 0.05mm / pass, until the thickness of the filler metal is rolled to 0.05mm;

[0125] 4) Observe the surface, remove the scrap at the edge, and remove the obvious crack, to obtain the filler metal foil.

[0126] (Four) Implement brazing

[0127] 1) ceramic plate is embedded into the groove of flange, gap is formed between the four sides of ceramic plate and flange, gold-based filler is made into long strip which is suitable for the gap, and the long strip of gold-based filler is embedded into the gap;

[0128] 2) gold-based filler is made into cone cylinder, the taper hole is suitable for metal contact, the outer diameter of cone cylinder is suitable for through hole, and the gold-based filler of cone cylinder is sleeved on the metal contact and inserted into the through hole;

[0129] 3) the assembled feedthrough is installed on the tooling and put into the induction furnace;

[0130] 4) vacuum is extracted to 10 -4 level, the vacuum pump is turned off, and high-purity argon is filled;

[0131] 5) the heating system of the induction furnace is turned on, the temperature rising speed is set to 15℃ / min, the highest temperature is set to 480℃, and the temperature is kept for 10min;

[0132] 6) the heating system is turned off, the solder is cooled with the furnace, when the furnace temperature is cooled to 100℃, the argon can be turned off, when the furnace temperature is cooled to room temperature, the furnace cavity is opened, and the brazed feedthrough is obtained.

[0133] Example 2

[0134] The same parts of example 2 and example 1 are not repeated, and the different parts are as follows:

[0135] Prepare each raw material according to the following requirements: gold foil with purity of 99.99%, specification of W20mm×T0.05mm, and mass of 25g; silicon powder with purity of 99.999%, specification of 500 mesh, and mass of 0.7g; indium foil with purity of 99.999%, specification of W10mm×T0.05mm, and mass of 0.4g.

[0136] When the brazing is implemented, the assembled feedthrough is installed on the tooling and put into the induction furnace, the heating system of the induction furnace can be turned on, the temperature rising speed is set to 15℃ / min, the highest temperature is set to 650℃, and the temperature is kept for 15min.

[0137] Example 3

[0138] The same parts of example 3 and example 1 are not repeated, and the different parts are as follows:

[0139] Prepare each raw material according to the following requirements: gold foil with purity of 99.99%, specification of W20mm×T0.05mm, and mass of 23g; silicon powder with purity of 99.999%, specification of 500 mesh, and mass of 1.2g; indium foil with purity of 99.999%, specification of W10mm×T0.05mm, and mass of 1.0g.

[0140] When the assembled feedthrough is installed on the tooling and placed in the induction furnace for brazing, the heating system of the induction furnace can be turned on, the temperature rising speed is set to 15℃ / min, the highest temperature is set to 650℃, and the temperature is kept for 15 min.

[0141] Example 4

[0142] Example 4 is the same as Example 1, and the differences are as follows:

[0143] (I) Prepare each raw material according to the following requirements:

[0144] Gold foil with a purity of 99.99% and a size of W20mm x T0.05mm, with a mass of 20.0g; silicon powder with a purity of 99.999% and a size of 500 mesh, with a mass of 0.70g.

[0145] (II) Gold-silicon alloy body smelting

[0146] The prepared raw materials are smelted in a vacuum medium-frequency induction furnace, wherein the configuration parameters of the induction furnace are as follows: the highest vacuum degree is 10 -5 Pa level, the highest temperature is about 1500℃, it is equipped with an electromagnetic stirring device and a rapid water cooling device, and high-purity argon gas with a purity of 99.999%. The smelting process of the gold-silicon alloy body includes the following steps:

[0147] S1: Unfold the gold foil, and smear the silicon powder on the surface of the gold foil within a length of 3cm from one end. Fold the gold foil and smear the silicon powder again. Repeat the above steps to fold the gold foil and smear the silicon powder alternately to mix the gold and silicon uniformly;

[0148] S2: Put the gold-silicon mixture into a graphite crucible and send it into the induction furnace for smelting;

[0149] S3: After vacuumizing to 10 -4 Pa level, turn off the vacuum pump and fill in high-purity argon gas;

[0150] S4: Slightly open the exhaust valve and adjust the air inlet flow to ensure that the argon gas pressure in the lumen is about 1kPa;

[0151] S5: Set the temperature rising speed to 15℃ / min, and raise the temperature to 1200℃. Keep the temperature for 10 min. Turn on the electromagnetic stirring for 2 min to promote the homogenization of the components. Keep the temperature for another 30 min and turn off the heating system.

[0152] S6: Open the water cooling to rapidly cool the furnace temperature to 100℃, and turn off the argon gas. When the furnace temperature cools to room temperature, open the furnace cavity and take out the cooled and shaped block-shaped gold-silicon alloy body.

[0153] (III) Gold-silicon alloy body shaping

[0154] The shaped bulk gold-silicon alloy body is rolled by a double-roller rolling machine to obtain a gold-silicon alloy body foil with a thickness of 0.05 mm.

[0155] (IV) Indium layer electroplating

[0156] The electroplating process of the indium layer includes the following steps:

[0157] S7: The rolled gold-silicon alloy body foil is chemically cleaned and then plasma-activated.

[0158] S8: The gold-silicon alloy body foil is placed in an electrolyte; the electrolyte mainly contains indium sulfate as a main salt and citric acid as a complexing agent to stabilize In 3+ , and the pH is controlled at 2-4;

[0159] S9: A current of 1 A / dm 2 is passed for 10 min to obtain a gold-based filler after electroplating of an indium layer; the thickness of the indium layer is about 2 μm (the deposition rate of indium is about 0.1-0.5 μm / min).

[0160] When the assembled feedthrough is installed on a tool and placed in an induction furnace for brazing, the heating system of the induction furnace can be turned on, the temperature rising speed is set to 15 ℃ / min, the highest temperature is set to 500 ℃, and the temperature is maintained for 12 min.

[0161] Comparative Example

[0162] Pure gold is used as a filler to braze the assembled feedthrough.

[0163] Test Method

[0164] 1. Test of the proportion of each element in the filler and whether it is uniformly distributed

[0165] After the middle part of the smelted filler is brittle fractured by liquid nitrogen, the scanning section is scanned by a scanning electron microscope EDS to obtain an energy spectrum characteristic map, and the proportion of each element in the material and whether it is uniformly distributed are analyzed according to the energy spectrum characteristic map.

[0166] 2. Test of the melting point of the filler

[0167] 5-10 mg of the smelted filler is weighed as a sample, the sample is placed in an induction furnace, the furnace temperature is first adjusted to a first temperature (for example, greater than 380 ℃), and the temperature is maintained for 30 min, the surface of the material is observed through a quartz furnace chamber to see whether there is a melting trace, the furnace temperature is increased by 20 ℃ on the basis of the first temperature, and the temperature is maintained for 30 min, until the surface of the material is visible melting trace, at this time, the temperature is recorded as the second temperature; the furnace temperature is increased by 20 ℃ on the basis of the second temperature, and the temperature is maintained for 30 min, and the material can be completely melted after observation. Therefore, the second temperature plus 20 ℃ can be taken as the melting point of the filler.

[0168] 3. Impact test is performed on the feedthrough, and the air tightness test is performed before and after the impact. The impact test is as follows:

[0169] In addition to the electrode lead or catheter, the implanted part of the active implantable medical device can be subjected to a mechanical impact test (such as the mechanical impact test in GB / T 2423.5-2019), and the test conditions are as follows:

[0170] A) Impact shape: half-sine or half-tangent;

[0171] B) Severity: peak acceleration: 5000 m / s (500 g);

[0172] C) Impact duration: 1 ms;

[0173] D) Direction and number of impacts: 1 impact in each of the 3 mutually perpendicular axes (i.e. X, Y and Z axes in the coordinate system) (a total of 6 impacts).

[0174] In addition, for example, the impact test can be performed according to the relevant technical document in the art, i.e. “Active implantable medical devices - Part 1: General requirements, safety, marking and manufacturer's information to be supplied - Impact test”.

[0175] The air tightness test procedure is as follows: turn on the helium leak detector and preheat for more than 15 min, prepare the brazing sample and the special test pad with a matching hole in the center. Wipe the helium leak detector's pumping platform clean, lay the silica gel test pad on it, and align the center hole with the pumping hole of the helium leak detector. Align the test area of the brazing sample with the hole on the test pad, and press the brazing sample firmly. Turn on the test switch and read the test data. The test data includes the leakage rate, which is used to judge whether the air tightness of the brazing sample is qualified; wherein when the leakage rate is ≤5×10 -9 atm·mL / s, it is determined that the air tightness of the brazing sample is qualified.

[0176] Test results:

[0177] 1. The test results of the proportion of each element in the gold-based filler after smelting in Examples 1-4 and whether it is uniformly distributed are shown in Table 1:

[0178] Table 1 Proportion of each element in gold-based filler

[0179]

[0180] From the data in Table 1, it is not difficult to see that according to the analysis of the energy spectrum characteristic map obtained from the scanning section, the proportions of each element at the section basically meet the expectation, except that part of indium is volatilized, and the distribution of each element is relatively uniform. The carbon element in Table 1 is precipitated due to the use of a graphite crucible for smelting, and O in Table 1 represents impurities, the content of which is low, meeting the requirement of long-term implantation; and the gold-based filler metal prepared by the preparation method of the gold-based filler metal is homogenized in composition, reducing segregation. Examples 1-3 are the test results of the bulk filler metal after smelting of silicon, indium and gold, and Example 4 is the test result of the bulk filler metal after smelting of silicon and gold.

[0181] 2, the test results of the melting point of the filler metal of Examples 1-4 are shown in Table 2:

[0182] Table 2 Melting point of gold-based filler metal

[0183] Example 1 Example 2 Example 3 Example 4 Melting point 400℃ 580℃ 580℃ 420℃

[0184] From the data in Table 2, it can be seen that the melting point of the gold-based filler metal prepared by Examples 1-4 is lower than 600℃, so the melting point of the gold-based filler metal is obviously lower than the melting point of the ceramic plate, the metal contact and the flange, which are the base materials, even if the thickness of the flange is thin, the deformation of the flange or the cracking phenomenon of the ceramic plate can be avoided, which is beneficial to the implementation of brazing.

[0185] 3, five of the feedthroughs prepared from Examples 1-4 and the comparative examples are selected as test samples, impact test is performed on the test samples, and air tightness test is performed on the test samples before and after impact, and the leakage rate test results are shown in Table 3:

[0186] Table 3 Leakage rate test results (unit: atm.mL / s)

[0187]

[0188] From the data in Table 3, it can be seen that the leakage rate test results of the feedthroughs brazed by the gold-based filler metal prepared by Examples 1-4 before and after impact test are not much different, and the leakage rate is less than 5x10 -9 atm.mL / s, so it can be determined that the air tightness test results of the test samples of Examples 1-4 are qualified. The air tightness test results of the test samples C5 and D5 of the feedthrough brazed by the pure gold filler metal in the comparative example before and after impact test are qualified, and the leakage rate is less than 5x10 -9 atm.mL / s; but the air tightness test results of the test samples A5, B5 and E5 after impact test are unqualified, and the leakage rate is more than 5x10 -9atm.mL / s. By analyzing the reason under microscope, it can be obviously seen that part of the brazing filler metal is dropped, that is, the bonding strength between the brazing filler metal and the base metal is not strong when pure gold brazing filler metal is used. It can be known that the bonding strength between the brazing filler metal and the base metal is good and the impact resistance is higher after indium element is added in the gold-based brazing filler metal.

[0189] It should be understood that the above detailed description of the application is only used for illustrative or explanatory purposes of the principles of the application, and does not constitute a limitation of the application. Therefore, any modification, equivalent replacement, improvement, etc. made without departing from the spirit and scope of the application shall be included in the protection scope of the application. In addition, the claims attached to the application are intended to cover all variations and modifications falling within the scope and boundary of the appended claims, or the equivalent forms of such scope and boundary.

Claims

1. A gold-based brazing material for brazing ceramics and metals in active implantable devices, characterized in that: The gold-based solder comprises the following components in percentage by mass: Silicon 2.0-10.0%; Indium 0.5-5.0%; Gold 85.0-97.5%; The remainder is impurities.

2. The gold-based solder according to claim 1, characterized in that The indium content calculated by mass percentage is 1.0-4.0%; the silicon content calculated by mass percentage is 2.5-5%.

3. The gold-based solder according to claim 1, characterized in that The purity of the gold is above 98%; preferably, the purity of the gold is above 99%; The purity of the silicon is above 99%; preferably, the purity of the silicon is above 99.9%; The purity of the indium is above 99%; preferably, the purity of the indium is above 99.9%.

4. The gold-based solder according to any one of claims 1 to 3, characterized in that The gold-based solder is made into any one of sheet, ring, strip or cone shape; The melting point of the gold-based solder is 350-600°C.

5. A method for preparing a gold-based brazing material for brazing ceramics and metals in active implantable devices, characterized in that: include: Gold raw materials are made into gold foil, indium raw materials are made into indium foil, and silicon raw materials are made into silicon powder; Weigh each raw material according to the preset mass percentage; Folding the gold foil into multiple layers according to a preset length, and applying silicon powder on the surface of each layer of the gold foil to obtain a gold-silicon mixture; Fold the indium foil and place it in the crucible, then put the gold-silicon mixture into the crucible and place the crucible into the induction furnace; Turn on the heating system of the induction furnace and set the heating rate to 10-20℃ / min. When the temperature reaches 1064-1264℃, keep it warm for 10-60 minutes. Turn on electromagnetic stirring for 2-5 minutes and keep warm again for 10-60 minutes; The heating system is turned off, and the cooling device of the induction furnace is turned on to cool down the temperature. When the furnace temperature cools down to room temperature, a formed block solder is obtained.

6. The method for producing gold-based solder according to claim 5, characterized in that: Also includes: The induction furnace is first vacuumed to 10 -4 level, and then filled with inert gas.

7. The method for producing gold-based solder according to claim 5, wherein: Also includes: The formed block solder is rolled and thinned by a multi-roll mill to obtain a preform with a set thickness; wherein the set thickness of the preform is 0.03-0.5 mm.

8. The method for producing gold-based solder according to claim 7, wherein: The method of rolling and thinning the formed block solder by a multi-roll mill to obtain a preform of a set thickness comprises: The deformation of the multi-roll mill is set to 0.03-0.2 mm / pass, and the formed block solder is rolled by the multi-roll mill until the solder thickness reaches a first threshold; The solder having a thickness of the first threshold is placed in an induction furnace for vacuuming and heating to 190-220° C. and then annealing; The annealed solder is rolled again using a multi-roll mill until the solder thickness reaches a second threshold; The brazing material is repeatedly annealed and rolled until it becomes a preform of a set thickness.

9. A method for preparing a gold-based brazing material for brazing ceramics and metals in active implantable devices, characterized in that: The gold-based solder comprises a gold-silicon alloy layer and an indium layer in contact with each other; the method comprising: Weigh each raw material according to the preset mass percentage; The gold raw material and the silicon raw material are smelted to obtain a formed bulk gold-silicon alloy body; The formed block-shaped gold-silicon alloy body is rolled and thinned by a multi-roll mill to obtain a gold-silicon alloy layer of a set thickness; The gold-silicon alloy layer is electroplated with an indium layer to obtain the gold-based solder; wherein the electrolyte is mainly indium sulfate, and citric acid is added as a complexing agent to stabilize In 3+ , pH is controlled at 2-4.

10. A method for manufacturing a feedthrough for an active implantable device, characterized in that: The feedthrough comprises a ceramic plate, a metal contact, and a flange, wherein the ceramic plate is provided with a plurality of through holes spaced apart, the metal contacts pass through the through holes, the flange is provided with a groove, the ceramic plate is embedded in the groove, and a gap is formed between the ceramic plate and the flange. The feedthrough manufacturing method comprises: embedding the long strip of gold-based solder into the gap; Sleeve the conical gold-based solder on the metal contact and insert it into the through hole, so that the conical gold-based solder is located between the metal contact and the ceramic plate; Installing the assembled feedthrough on a tool and placing it in an induction furnace; Turn on the heating system of the induction furnace and set the heating rate to 5-25°C / min. When the temperature reaches the set threshold, keep it warm for 10-60 minutes; the set threshold is 20-100°C higher than the melting point of the gold-based solder; Turn off the heating system and cool the furnace until the furnace temperature cools to room temperature to obtain the brazed feedthrough.

11. An active implantable device, characterized in that: The invention comprises a feedthrough manufactured by the feedthrough manufacturing method according to claim 10.

Images