A medical feedthrough ceramic structure that facilitates hermeticity of a weld

Abstract

The utility model relates to the technical field of feedthrough connector, concretely to a medical feedthrough ceramic structure being favorable to welding air tightness, including ceramic insulator, metal titanium flange and platinum iridium wire, metal titanium flange inner chamber size is greater than ceramic insulator outer size, is equipped with the bulge that extends to the inside in the bottom, is used for supporting ceramic insulator, the outer circle of ceramic insulator upper portion is equipped with L shape chamfer, forms upper portion boss structure, boss top is higher than metal titanium flange upper surface, bottom is lower than metal titanium flange upper surface, ceramic insulator is equipped with a plurality of platinum iridium wire and is worn, the utility model discloses a L shape chamfer is added to the edge of ceramic insulator, forms a step plane, and the film rate is fast in the parallel target surface direction film formation in combination with magnetron sputtering film formation, and the film layer quality is firm features. Can solve the problem of poor welding between ceramic insulator side edge and metal titanium flange.

Description

Technical Field

[0001] This utility model relates to the field of feedthrough connector technology, specifically a medical feedthrough ceramic structure that is beneficial for welding airtightness. Background Technology

[0002] With the continuous development of medical technology, medical device technology is also constantly advancing. Among these advancements, implantable medical devices are being continuously developed and applied, leading to a growing market. Applications of implantable devices such as cochlear implants, pacemakers, neurostimulation therapy devices, and brain-computer interfaces all rely heavily on feedthrough components.

[0003] Utility model patent CN202023212546.3, published on November 9, 2021, proposes an implantable dual-wire micro ceramic feedthrough connector, comprising a metal flange, an insulator, wires, and a sealing body. The metal flange is sleeved on the outside of the insulator, and the insulator has through holes corresponding to the wires. The wires pass through the through holes, with the upper end of the wires used to connect to the signal output terminal inside the implant and the lower end used to connect to an external extension wire. A sealing body is provided between the wires and the insulator, and between the insulator and the metal flange, for connection and sealing. The bottom of the metal flange protrudes inward to form an inner groove for supporting and fixing the insulator. The inner groove has a T-shaped cross-section; the wires are configured as dual wires, and the initial length of the wires is fixed, but they can be cut later as needed.

[0004] However, magnetron sputtering deposition suffers from the directional nature of the sputtered metal particles. These particles typically move at high speed perpendicular to the target surface, resulting in a higher deposition rate and stronger film adhesion in the direction parallel to the target surface on the substrate. Conversely, in the direction perpendicular to the target surface and parallel to the sputtered particle movement, the deposition rate is slower, and the film adhesion is weaker. This weak adhesion makes the film prone to detaching from the solder during welding, and it also fails to meet airtightness requirements. Traditional ceramic designs have vertical sides, leading to a loose film quality across the entire surface during metallization, resulting in a lack of sealing during welding and a high risk of air leakage.

[0005] Another problem exists in the brazing process: because gold solder has excellent compatibility with titanium, if the solder is applied to the titanium flange step, the gold solder will preferentially wet and bond to the titanium flange surface when it melts at high temperature, and the excess solder will then flow to the surface of the ceramic metallized layer. This can easily result in a lack of solder on the surface of the ceramic metallized layer. Utility Model Content

[0006] This invention provides a medical feedthrough ceramic structure that improves weld airtightness, solving the problem that when metallizing medical ceramics by magnetron sputtering, the sputtering rate and adhesion force of the film layer on the front and side of the ceramic are inconsistent due to the directional nature of magnetron sputtering, resulting in weak sidewall welding or poor airtightness after welding.

[0007] The technical solution of this utility model is as follows:

[0008] A medical feedthrough ceramic structure that improves weld airtightness includes a ceramic insulator, a titanium flange, and a platinum-iridium wire. The inner cavity of the titanium flange is larger than the outer dimension of the ceramic insulator, and the bottom has an inwardly extending protrusion for supporting the ceramic insulator.

[0009] The upper outer ring of the ceramic insulator has an L-shaped chamfer, forming an upper boss structure. The top of the boss is higher than the upper surface of the metal titanium flange, and the bottom is lower than the upper surface of the metal titanium flange.

[0010] Several platinum-iridium wires are threaded through the ceramic insulator.

[0011] The outer contour of a ceramic insulator is cylindrical or slotted.

[0012] A stress table is provided around the outside of the titanium flange, and the stress table is located at the bottom of the titanium flange.

[0013] The thickness of the stress table is greater than the thickness of the protrusion.

[0014] The upper boss of the ceramic insulator is centered, and the distance between the outer wall of the boss and the outer wall of the ceramic insulator is 0.2mm.

[0015] A 2-4 μm metal film is deposited on the surface of the ceramic insulator.

[0016] The inner ring wall of the titanium flange has a vertical structure.

[0017] Several through holes are opened in the middle of the ceramic insulator to accommodate the insertion of platinum-iridium wires. A ring-shaped brazing filler hole is arranged around the upper end of the through holes, and the diameter of the brazing filler hole is larger than that of the through holes.

[0018] The solder placement hole is connected to the platinum-iridium wire via a gold inner solder ring.

[0019] The inner wall of the upper part of the titanium flange is connected to the bottom of the boss by a gold outer weld ring.

[0020] Beneficial effects:

[0021] (1) This application creates a stepped plane by adding an L-shaped chamfer to the edge of the ceramic insulator. Combined with the advantages of magnetron sputtering film deposition, which has a fast film deposition rate and strong film quality in the direction parallel to the target surface, this can solve the problem of poor welding between the side of the feedthrough ceramic insulator and the titanium flange.

[0022] (2) Adding an L-shaped chamfer to the edge of the ceramic insulator increases the contact area between the solder and the ceramic insulator side, which is beneficial to the welding strength and welding airtightness.

[0023] (3) This application does not require step treatment on the inner ring of the metal titanium flange, which simplifies the structural design of the metal titanium flange.

[0024] (4) The solder assembly is close to the ceramic insulator side. When the solder melts at high temperature, it will preferentially combine with the ceramic insulator and then flow to the metal titanium flange side, which helps to reduce the phenomenon of missing solder at the edge of the ceramic insulator after welding. Attached Figure Description

[0025] In the attached diagram:

[0026] Figure 1 This is a cross-sectional view of Example 1;

[0027] Figure 2 This is a schematic diagram of the overall structure of Example 1;

[0028] Figure 3 This is a top view of Example 1;

[0029] Figure 4 This is a cross-sectional view of Example 2;

[0030] Figure 5 This is a schematic diagram of the overall structure of Example 2;

[0031] Figure 6 This is a top view of Example 2.

[0032] The components represented by the various reference numerals in the diagram are:

[0033] 1. Ceramic insulator; 2. Metal titanium flange; 3. Platinum-iridium wire; 4. Gold inner weld ring; 5. Stress table; 6. Through hole; 7. Brazing filler metal placement hole; 8. Gold outer weld ring. Detailed Implementation

[0034] The present invention will be further described below with reference to the accompanying drawings of the embodiments thereof.

[0035] Example 1

[0036] See Figure 1 A medical feedthrough ceramic structure that is beneficial to welding airtightness includes a ceramic insulator 1, a titanium flange 2 and a platinum-iridium wire 3. The inner cavity size of the titanium flange 2 is larger than the outer size of the ceramic insulator 1, and the bottom is provided with an inwardly extending protrusion for supporting the ceramic insulator 1.

[0037] The outer contour of the ceramic insulator 1 is cylindrical. The upper outer ring of the ceramic insulator 1 is provided with an L-shaped chamfer to form an upper boss structure. The top of the boss is higher than the upper surface of the metal titanium flange 2, and the bottom is lower than the upper surface of the metal titanium flange 2.

[0038] Several platinum-iridium wires 3 are threaded through the ceramic insulator 1.

[0039] Adding an L-shaped chamfer to the edge of the ceramic insulator creates a stepped plane. Combined with the advantages of magnetron sputtering film deposition—fast film deposition rate and robust film quality in the direction parallel to the target surface—this method can solve the problem of poor welding between the side of the feedthrough ceramic insulator and the titanium flange.

[0040] The inner wall of the titanium flange 2 has a vertical structure, and a stress plate 5 is arranged around the outer side of the titanium flange 2, such as... Figure 3 The stress table 5 is located at the bottom of the titanium flange 2, and the thickness of the stress table 5 is greater than the thickness of the protrusion.

[0041] The L-shaped chamfer increases the contact area between the solder and the ceramic side, as well as the space for the solder to fill, which is beneficial to the welding strength and weld airtightness. Therefore, no step treatment is required on the inner wall of the titanium flange 2, which can simplify the structural design of the titanium flange.

[0042] The main metallization methods for ceramic insulators 1 are the molybdenum-manganese method and magnetron sputtering. The molybdenum-manganese slurry is applied to designated areas on the surface of the ceramic insulator 1, and then sintered onto the surface under wet hydrogen conditions, achieving selective metallization of the ceramic insulator 1 surface. This method is widely used in the field of electro-vacuum and is suitable for metallizing the insulating ceramics of larger feedthrough connectors. Magnetron sputtering is a technique that uses energetic particles to bombard a target surface in a vacuum, causing the ejected particles to deposit on a substrate. Typically, low-pressure inert gas glow discharge is used to generate incident ions, with an electromagnetic field controlling the ion incident direction, and the cathode serving as the target material. This method is suitable for various metal target materials, and the high-energy target particles can pass through narrow pores, making it suitable for coating small-sized components. Medical feedthrough ceramic insulators 1 are mostly small-volume ceramics, therefore magnetron sputtering is generally chosen for ceramic metallization.

[0043] Magnetron sputtering coating utilizes the directionality of the target metal particles ejected during sputtering. Generally, the sputtered particles move at high speed along the direction perpendicular to the target surface, resulting in a higher film formation rate and stronger film adhesion in the direction parallel to the target surface of the substrate.

[0044] The specific operation method is as follows: Ceramic insulator 1 is placed directly below the target, and a metallized film layer is deposited on the surface of ceramic insulator 1. Since magnetron sputtering has a good film deposition rate and film adhesion on the surface parallel to the target, the bottom surface of the L-shaped edge of ceramic insulator 1 is parallel to the target surface, resulting in a better quality film layer. A 2-4 μm metallized film layer is deposited on the surface of ceramic insulator 1.

[0045] Combination Figure 2To aid understanding, several through holes 6 are opened in the middle of the ceramic insulator 1 to accommodate the insertion of platinum-iridium wire 3. A ring-shaped brazing filler hole 7 is arranged around the upper end of the through holes 6, and the diameter of the brazing filler hole 7 is larger than that of the through holes 6.

[0046] The brazing filler hole 7 is connected to the platinum-iridium wire 3 by the inner gold welding ring 4, and the inner wall above the titanium flange 2 is connected to the bottom of the boss by the outer gold welding ring 8.

[0047] The metallized ceramic insulator 1, titanium flange 2, and platinum-iridium wire 3 are assembled together using an inner gold welding ring 4 and an outer gold welding ring 8. During assembly, due to the boss structure of the ceramic insulator 1, the distance between the outer wall of the boss and the outer wall of the ceramic insulator 1 is 0.2 mm. This creates a relatively wide gap between the outer wall of the boss of the ceramic insulator 1 and the inner wall of the titanium flange 2, allowing sufficient solder to be filled and supported on the ceramic.

[0048] After the assembled product is placed in a brazing furnace and vacuumed, it is brazed at a higher temperature. During brazing, the gold outer welding ring 8 forms a dense, leak-proof weld on the side of the ceramic insulator 1. The upper boss of the ceramic insulator 1 is centrally located. Due to the characteristics of magnetron sputtering film formation, the film quality of the outer wall of the boss and the outer wall of the ceramic insulator 1 is relatively poor, and the weld between them and the gold outer welding ring 8 is not dense enough. A dense weld is formed between the titanium flange 2 and the gold outer welding ring 8. Therefore, the sealing of this feedthrough sidewall mainly relies on the welded sealing ring formed by the gold outer welding ring 8 connecting the horizontal surface of the boss and the inner wall of the titanium flange 2.

[0049] Combining the advantages of magnetron sputtering film deposition—high deposition rate and robust film quality in the direction parallel to the target surface—this method can solve the problem of poor welding between the side of the ceramic insulator 1 and the titanium flange 2.

[0050] Example 2

[0051] Reference Figure 4-6 The outer contour of the ceramic insulator 1 is slotted, and a through hole 6 is opened in the middle to insert a platinum-iridium wire 3. The through holes 6 are arranged in two rows, with four in each row, evenly distributed.

[0052] Specific steps for using this utility model:

[0053] 1. Clean / dry the ceramic body with edges and protrusions.

[0054] 2. Place the cleaned and dried ceramic insulator 1 under the target of the magnetron sputtering coating machine. Adjust the target surface inside the magnetron sputtering machine to a near-vertical position. The product should be rotating on the tray. After the vacuum in the chamber is evacuated to below 1*10⁻³ Pa, turn on the target power source to deposit a 2-4 μm metal film on the ceramic surface. The metal film can be made of biocompatible materials such as titanium or niobium.

[0055] 3. Grind off the top film layer of the metallized ceramic insulator 1 and clean it thoroughly. Grinding off the top film layer is mainly because the top surface does not need to be welded. After the metal film layer is removed, it can provide insulation and prevent electrical conduction between the insulator and the platinum-iridium wire 3, and between the platinum-iridium wire 3 and the flange.

[0056] 4. Insert the ceramic insulator 1 into the metal titanium flange 2, then insert the platinum-iridium wire 3 into the through hole 6 of the ceramic insulator 1, and put the gold inner welding ring 4 on the platinum-iridium wire 3, and place the gold outer welding ring 8 on the horizontal surface of the boss.

[0057] 5. Place the assembled product into a brazing furnace for heating and welding. After welding, test the product for air tightness. The leakage rate should be less than 1*10-9ATM.CC / SEC.

Claims

1. A medical feedthrough ceramic structure that improves weldability and airtightness, comprising a ceramic insulator (1), a titanium flange (2), and a platinum-iridium wire (3), characterized in that: The inner cavity of the titanium flange (2) is larger than the outer dimension of the ceramic insulator (1), and the bottom is provided with an inwardly extending protrusion for supporting the ceramic insulator (1); The ceramic insulator (1) has an L-shaped chamfer on the upper outer ring to form an upper boss structure. The top of the boss is higher than the upper surface of the metal titanium flange (2), and the bottom is lower than the upper surface of the metal titanium flange (2). The ceramic insulator (1) is threaded with several platinum-iridium wires (3).

2. The medical feedthrough ceramic structure according to claim 1, which is beneficial to weld airtightness, is characterized in that, The outer contour of the ceramic insulator (1) is cylindrical or slotted.

3. The medical feedthrough ceramic structure according to claim 1, which is beneficial to weld airtightness, is characterized in that, A stress table (5) is provided around the outside of the titanium flange (2), and the stress table (5) is located at the bottom of the titanium flange (2).

4. A medical feedthrough ceramic structure that improves weldability and airtightness according to claim 3, characterized in that, The thickness of the stress table (5) is greater than the thickness of the protrusion.

5. A medical feedthrough ceramic structure that improves weldability and airtightness according to claim 1, characterized in that, The upper boss of the ceramic insulator (1) is centrally located, and the distance between the outer wall of the boss and the outer wall of the ceramic insulator (1) is 0.2 mm.

6. A medical feedthrough ceramic structure that improves weldability and airtightness according to claim 1, characterized in that, A 2-4 μm metal film is deposited on the surface of the ceramic insulator (1).

7. A medical feedthrough ceramic structure that improves weldability and airtightness according to claim 1, characterized in that, The inner ring wall of the titanium flange (2) has a vertical structure.

8. A medical feedthrough ceramic structure that improves weldability and airtightness according to claim 1, characterized in that, The ceramic insulator (1) has several through holes (6) in the middle for inserting platinum-iridium wire (3). The upper end of the through holes (6) is surrounded by annular brazing filler holes (7), and the diameter of the brazing filler holes (7) is larger than that of the through holes (6).

9. A medical feedthrough ceramic structure that improves weldability and airtightness according to claim 8, characterized in that, The brazing filler hole (7) is connected to the platinum-iridium wire (3) via a gold inner brazing ring (4).

10. A medical feedthrough ceramic structure that improves weldability and airtightness according to claim 1, characterized in that, The inner wall above the titanium flange (2) is connected to the bottom of the boss by a gold outer welding ring (8).

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