CN113099603B

CN113099603B - Ceramic substrate for implantable medical device and method for manufacturing same

Info

Publication number: CN113099603B
Application number: CN202110352667.8A
Authority: CN
Inventors: 韩明松; 夏斌; 赵瑜
Original assignee: Shenzhen Sibionics Technology Co Ltd
Current assignee: Shenzhen Silicon Bionics Technology Co ltd
Priority date: 2017-12-29
Filing date: 2018-12-31
Publication date: 2022-06-21
Anticipated expiration: 2038-12-31
Also published as: CN109574637B; CN113068298A; WO2019129303A1; CN113068298B; CN113099603A; CN108966491A; CN209748985U; CN108966491B; CN109574637A; CN109688695A; CN109688695B

Abstract

The present invention relates to a ceramic substrate for an implantable medical device, comprising: a ceramic substrate formed by laminating and firing a plurality of ceramic sheets, each ceramic sheet having a plurality of through holes; a feed-through electrode fired from a first conductive paste filling each via; a cover pad fired with the second conductive paste and covering the feed-through electrode of the outermost ceramic sheet; and a wiring conductor formed by firing the third conductive paste; wherein each ceramic sheet is co-fired with the first and second conductive pastes at a temperature of 1450 ℃ to 1600 ℃ and in the co-firing, a ceramic paste is applied between the ceramic substrate and the feedthrough electrode. Therefore, in the co-firing process, the ceramic slurry in a molten state can penetrate into the gap between the ceramic substrate and the feed-through electrode, and the air tightness between the ceramic substrate and the feed-through electrode is improved.

Description

Ceramic substrate for implantable medical device and method for manufacturing same

The application is filed as31/12/2018Application No. is201811652362.3The invention is named asCeramic material Substrate and method for manufacturing the sameDivisional application of the patent application.

Technical Field

The present invention relates to a ceramic substrate for an implantable medical device and a method for manufacturing the same.

Background

Currently, implantable medical devices have been widely used in various aspects such as restoring body functions, improving quality of life, or saving life. Examples of such implantable medical devices include cardiac pacemakers, deep brain stimulators, cochlear implants, artificial retinas, and the like that can be implanted in the body.

Since the implantable medical device needs to be implanted into the body and remain in the body for a long time, the implantable medical device needs to be exposed to a complex physiological environment in the body, and after long-term implantation, the portion of the implantable medical device in contact with the surrounding tissue may undergo physical or chemical reactions such as aging, degradation, cracking, re-crosslinking and the like, which may adversely affect the implanted object, for example, cause adverse biological reactions such as inflammation and the like. Therefore, requirements for biosafety, long-term implantation reliability, and the like are very high for implantable medical devices.

In order to ensure the requirements of biosafety and long-term implantation reliability of the implantable medical device, on one hand, a sealed housing is needed to isolate non-biosafety components such as a chip, a Printed Circuit Board (PCB) and the like in the implantable medical device from an implanted part (such as blood, tissue or bone); on the other hand, functional leads for signal interaction with, for example, stimulation components, also need to be led out of the sealed housing.

In consideration of biosafety and long-term reliability of an implantable medical device, the hermetic case often has glass, ceramic, or the like with good biosafety as a substrate (substrate), and the hermetic structure is formed together by covering a metal lid or the like with good biosafety on the substrate. In such a sealing structure, the substrate generally has a plurality of through holes (via) filled with feed-through electrodes. In addition, the electronic components packaged inside the sealed case perform signal interaction with the outside via the feed-through electrodes. Therefore, in an implantable medical device, such a substrate has both the function of sealing and isolating and the function of communicating with the outside world.

Disclosure of Invention

In a conventional ceramic substrate, a plurality of cylindrical through holes are generally drilled (drilled) in a ceramic sheet as a base, and then a metal paste is filled in the through holes, followed by a sintering process. However, in the process of sintering (co-firing) the metal paste and the ceramic substrate, the ceramic sheet as the ceramic substrate is often heated unevenly to cause different degrees of contraction or expansion of the metal in each through hole, and as a result, the adhesion between the metal and the through hole of the ceramic sheet is poor, resulting in poor air tightness of the conventional sealing structure and affecting long-term reliability of the use of the implantable medical device.

In addition, currently, alumina is commonly used as a material of ceramic sheets in implantable medical devices, for example. In such a ceramic substrate, generally, the higher the content of alumina, the better the biosafety of the ceramic substrate, and the higher the strength. However, the higher the alumina content, the higher the sintering temperature of the ceramic substrate tends to be, for example, in the case of high purity alumina ceramics having an alumina content of 99% (mass fraction, the same applies hereinafter), the sintering temperature tends to exceed 1650 ℃, and even approach a high temperature of about 2000 ℃, at which the ceramics are difficult to sinter together with other materials such as metals, and thus the application of the high purity alumina ceramic substrate is not facilitated.

The present invention has been made in view of the above-described conventional circumstances, and an object thereof is to provide a ceramic substrate capable of improving the airtightness even when the ceramic substrate is sintered at a low temperature (for example, 1450 ℃ to 1600 ℃), and a method for manufacturing the same.

One aspect of the present invention relates to a ceramic substrate characterized in that: the method comprises the following steps: a ceramic substrate formed by stacking and firing a plurality of ceramic sheets each having a plurality of through holes; a feed-through electrode fired from a first conductive paste filling each of the through-holes; and a covering pad fired by a second conductive paste and covering the feedthrough electrode of the ceramic sheet at the outermost layer, wherein each of the ceramic sheets is co-fired with the first conductive paste and the second conductive paste at a temperature of 1450 ℃ to 1600 ℃, and in the co-firing, a ceramic paste is coated between the ceramic substrate and the feedthrough electrode.

In the invention, the ceramic substrate can be formed by co-firing a ceramic wafer, the first conductive paste and the second conductive paste at 1450-1600 ℃. In co-firing, a ceramic slurry is coated between the ceramic substrate and the feed-through electrode. In this case, during co-firing, the ceramic slurry in a molten state can penetrate into the gap between the ceramic substrate and the feed-through electrode, improving the hermeticity of the ceramic substrate and the feed-through electrode. Further, since the plurality of ceramic sheets are stacked and sintered, the ceramic sheets are more easily fired, and the bonding force between the feedthrough electrode, the cover pad, and the ceramic base can be improved, whereby the sintering temperature can be reduced and the airtightness of the ceramic substrate can be improved.

In the ceramic substrate according to the aspect of the present invention, the ceramic sheet may be made of alumina ceramic. This can improve the biosafety and long-term reliability of the ceramic substrate.

In the ceramic substrate according to the aspect of the present invention, the ceramic sheet may have upper and lower surfaces, and the through-hole may penetrate the upper and lower surfaces of the ceramic sheet. In this case, the upper and lower surfaces of the ceramic sheet can be made electrically connected when the feed-through electrode is filled in the via hole.

In the ceramic substrate according to the aspect of the present invention, the first conductive paste may be formed of one or more selected from a tungsten paste, a molybdenum-manganese paste, a silver paste, a gold paste, and a platinum paste. Therefore, the feed-through electrode formed by firing the first conductive paste is more matched with the performance parameters of the ceramic substrate, the connection structure strength is higher, the electrical performance of the ceramic substrate can be improved, and the long-term reliability of the ceramic substrate can be further improved.

In the ceramic substrate according to the aspect of the present invention, the ceramic slurry is made of alumina, and the composition thereof is identical to that of the ceramic sheet. This enables the ceramic paste in the molten state to better penetrate into the gap between the ceramic substrate and the feed-through electrode.

Another aspect of the present invention relates to a method for manufacturing a ceramic substrate, characterized in that: the method comprises the following steps: preparing a plurality of ceramic sheets and forming a plurality of through holes on each of the ceramic sheets; filling a first conductive paste as a feed-through electrode in each of the through holes of each of the ceramic sheets; forming a cover pad covering the feed-through electrode on an outer surface of the outermost ceramic sheet using a second conductive paste; and sequentially laminating each of the ceramic sheets, and co-firing each of the ceramic sheets together with the first conductive paste and the second conductive paste at a temperature of 1450 ℃ to 1600 ℃, in which a ceramic paste is applied between a plurality of ceramic sheets and the first conductive paste.

In the present invention, each ceramic sheet is co-fired together with a first conductive paste and a second conductive paste at a temperature of 1450 ℃ to 1600 ℃, in which a ceramic paste is coated between a plurality of ceramic sheets and the first conductive paste. In this case, during co-firing, the ceramic slurry in a molten state can penetrate into the gap between the ceramic substrate and the feed-through electrode, improving the hermeticity of the ceramic substrate and the feed-through electrode. Further, since the plurality of ceramic sheets are stacked and sintered, the ceramic sheets are more easily fired, and the bonding force between the feedthrough electrode, the cover pad, and the ceramic base can be improved, whereby the sintering temperature can be reduced and the airtightness of the ceramic substrate can be improved.

In the method for manufacturing a ceramic substrate according to another aspect of the present invention, the ceramic sheet may be made of alumina ceramic. This can improve the biosafety and long-term reliability of the ceramic substrate.

In the method of manufacturing a ceramic substrate according to another aspect of the present invention, the ceramic sheet has upper and lower surfaces, and the through-hole penetrates the upper and lower surfaces of the ceramic sheet. In this case, the upper and lower surfaces of the ceramic sheet can be made electrically connected when the through-hole is filled with the feed-through electrode.

According to the present invention, it is possible to provide a ceramic substrate and a method for manufacturing the same, which can improve the airtightness between the ceramic base and the feed-through electrode while reducing the sintering temperature.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention, illustrate embodiments of the invention and together with the description serve to explain the invention and do not constitute a limitation of the invention. In the drawings:

fig. 1 is a perspective view showing a ceramic substrate according to an embodiment of the present invention.

Fig. 2 is a plan view showing the ceramic substrate shown in fig. 1.

Fig. 3 is a schematic view showing a cross-sectional structure of the ceramic substrate shown in fig. 2 taken along a line a-a'.

Fig. 4 is a partially enlarged view showing the ceramic substrate shown in fig. 3.

Fig. 5 is a schematic view showing a cross-sectional structure of the ceramic substrate shown in fig. 2 taken along a line a-a'.

Fig. 6 is a partially enlarged view showing the ceramic substrate shown in fig. 5.

Fig. 7 is a flowchart showing a manufacturing process of a ceramic substrate according to an embodiment of the present invention.

Description of the symbols:

1 … ceramic substrate, 10 … ceramic substrate, 110 … ceramic sheet, 111 … via, 120 … ceramic sheet, 130 … ceramic sheet, 140 … ceramic sheet, 20 … feed-through electrode, 30 … wiring conductor.

Detailed Description

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description, the same components are denoted by the same reference numerals, and redundant description thereof is omitted. The drawings are schematic, and the proportions of the dimensions of the components and the shapes of the components may be different from the actual ones.

Fig. 1 is a perspective view showing a ceramic substrate according to an embodiment of the present invention. Fig. 2 is a plan view showing the ceramic substrate shown in fig. 1. Fig. 3 is a schematic view showing a cross-sectional structure of the ceramic substrate shown in fig. 2 taken along a line a-a'. Fig. 4 is a partially enlarged view showing the ceramic substrate shown in fig. 3. Fig. 5 is a schematic view showing a cross-sectional structure of the ceramic substrate shown in fig. 2 taken along a line a-a'. Fig. 6 is a partially enlarged view showing the ceramic substrate shown in fig. 5.

In the present embodiment, as shown in fig. 1 to 4, the ceramic substrate 1 may include a ceramic base 10, a feed-through electrode 20, and a cover pad (not shown). The ceramic substrate 10 may be formed by stacking and firing a plurality of ceramic sheets. Each ceramic sheet may have a plurality of through-holes 111. Feed-through electrode 20 may fill each via 111, and feed-through electrode 20 may be fired from a first conductive paste. A cover pad may be coated on each feed-through electrode 20, and the cover pad may be fired from a second conductive paste. Each ceramic sheet is co-fired with the first and second conductive pastes at a temperature of 1450 ℃ to 1600 ℃, and in the co-firing, a ceramic paste is coated between the ceramic substrate and the feedthrough electrode.

The ceramic substrate 1 according to the present embodiment can be formed by stacking and firing a plurality of ceramic sheets. In this case, since a plurality of ceramic sheets are stacked and sintered, the ceramic sheets are more easily fired, and the bonding force between the feed-through electrode 20, the cover pad, and the ceramic base 10 can be improved. This can reduce the sintering temperature and improve the airtightness of the ceramic substrate 1.

The feed-through electrode 20 of the ceramic substrate 1 according to the present embodiment can be connected to an external component such as a coil and a stimulation component (not shown) via a functional lead (not shown), thereby realizing processing of a stimulation signal and signal interaction.

In the present embodiment, the ceramic substrate 10 may include a plurality of ceramic sheets. A plurality of ceramic sheets may be sequentially laminated to form the ceramic substrate 10. Among other things, in some examples, the ceramic substrate 10 may be composed of, for example, four ceramic sheets. As shown in fig. 1, a ceramic sheet 110, a ceramic sheet 120, a ceramic sheet 130, and a ceramic sheet 140 are sequentially laminated to form a ceramic substrate 10. However, the present embodiment is not limited thereto, and the number of ceramic sheets constituting the ceramic substrate 10 is not particularly limited, and may be, for example, two, three, or five or more ceramic sheets. Therefore, the ceramic sheet layers smaller than or larger than four can be arranged according to different application requirements, and the requirements of different implantable medical devices on the structure of the ceramic substrate 1 can be met.

In addition, in the present embodiment, each ceramic sheet may be composed of a bioceramic. In some examples, each ceramic sheet may be made of a material selected from alumina (formula Al)₂O₃Including single crystal sapphire and ruby, or polycrystalline alpha sapphire), zirconia (formula ZrO)₂Which comprises magnesium oxide partially stabilized oxygenZirconium oxide (Mg-PSZ)), yttria-stabilized tetragonal zirconia polycrystal (Y-TZP), ceria-stabilized tetragonal zirconia polycrystal (Ce-TZP), and the like. Therefore, the requirements of the implanted medical device on the biological safety of materials can be met. For example, the ceramic sheet may be composed of alumina.

In some examples, each ceramic sheet may be composed of a different kind of ceramic. However, the present embodiment is not limited thereto, and the ceramic sheets may be made of the same kind of ceramic. For example, each ceramic sheet may be composed of the same ceramic but with different amounts of each component. The individual ceramic sheets can also consist of the same ceramic and have the same content of the individual components.

In the present embodiment, each ceramic sheet is preferably made of alumina (Al) of 96% or more (mass fraction, the same applies hereinafter)₂O₃) And (4) forming. More preferably, each ceramic sheet may be made of 99% or more of alumina (Al)₂O₃) And (4) forming. In some examples, each of ceramic sheets 110-140 may be composed of greater than 99.99% alumina (Al)₂O₃) And (4) forming. Generally, in each ceramic sheet, alumina (Al) is attached to₂O₃) The increase in mass fraction increases the main crystal phase, and the physical properties of the respective ceramic sheets are gradually improved, for example, the pre-compression strength, the bending strength, and the elastic modulus are also improved accordingly. From this, it is considered that the mass fraction of alumina (Al) is higher₂O₃) Will exhibit better biosafety and long-term reliability.

In addition, in the present embodiment, each ceramic sheet may be composed of alumina ceramics having the same component content. In some examples, ceramic sheets 110 through 140 are preferably composed of alumina (Al) having a component content of 99.99% or more₂O₃) And (4) forming. However, the present embodiment is not limited thereto, and each ceramic sheet may be composed of the same kind of ceramics having different component contents. Therefore, the ceramic substrate 1 can be adjusted according to actual needs, so that different requirements for the ceramic substrate 1 under different environmental conditions are met.

In the present embodiment, as described above, the ceramic substrate 10 may be formed by stacking and firing a plurality of ceramic sheets. However, the present embodiment is not limited thereto, and it may of course be prepared in other ways, for example by press forming from a plurality of ceramic sheets. Therefore, the process requirements under the same conditions can be met.

In the present embodiment, as shown in fig. 1, the ceramic sheet 110, the ceramic sheet 120, the ceramic sheet 130, and the ceramic sheet 140 may be stacked and fired to form the ceramic substrate 10. In some examples, the respective ceramic sheets (ceramic sheet 110 to ceramic sheet 140) may be sequentially laminated and co-fired together with the first conductive paste and the second conductive paste to form the ceramic substrate 10, the feed-through electrode 20 (described later), and the cover pad (described later). In other examples, the ceramic sheets 110 to 140 may be sequentially laminated, and co-fired together with the first conductive paste and the second conductive paste at a temperature of 1450 ℃ to 1600 ℃ to form the ceramic substrate 10, the feedthrough electrode 20 (described later), and the covering pad 30 (described later). Preferably, the temperature of co-firing may be 1550 ℃ to 1600 ℃.

Generally, the firing temperature of the existing high-purity alumina ceramics (the content is more than 99.9%) needs to be as high as 1680 ℃ to 1990 ℃. In contrast, in the present embodiment, by controlling the firing temperature of the ceramic substrate 10 at 1450 to 1600 ℃, preferably 1550 to 1600 ℃ as described above, on the one hand, it is possible to satisfy both the firing molding of the metal (the feedthrough electrode 20 and the covering pad) and the firing molding of the ceramic (the ceramic substrate 10); on the other hand, low-temperature co-firing of the ceramic sheet (forming the ceramic substrate 10) and the conductive slurry (forming the feed-through electrode 20 and the cover pad) can be realized, so that the bonding strength of the fired ceramic substrate 10, the feed-through electrode 20 and the cover pad is improved, the preparation efficiency of the ceramic substrate 1 is effectively improved, and the production cost of the ceramic substrate 1 is reduced. In addition, during the co-firing process, the ceramic slurry in a molten state can penetrate into the gap between the ceramic substrate and the feed-through electrode, and the air tightness between the ceramic substrate and the feed-through electrode is improved.

In addition, in consideration of the difference in expansion index between the ceramic sheet and the metal material, in the present embodiment, a low-temperature preheating step may be further included. In some examples, pre-bonding of the ceramic (ceramic substrate 10) to the metal (feedthrough electrode 20 and cover pad) may be done at a lower temperature (e.g., below 500 ℃) to prevent warping, cracking, etc., from occurring due to too high a co-firing temperature or too fast a co-firing rate.

Generally, when the heating rate is too high, the ceramic substrate 1 is likely to have a gas or an incomplete sintering phenomenon; the heating rate is too slow, which prolongs the sintering process time, reduces the manufacturing efficiency and increases the manufacturing cost. Therefore, in the present embodiment, it is also possible to include controlling the temperature rise rate in the co-firing process. Therefore, the phenomenon of incomplete gas or sintering in the ceramic substrate 1 can be prevented, the density of the ceramic substrate 1 is ensured, the preparation efficiency of the ceramic substrate 1 can be effectively improved, and the production cost of the ceramic substrate 1 is reduced.

In addition, it is considered that a certain amount of organic components and binder phase may be added during the preparation of the ceramic substrate 1. In this embodiment, a thermal degreasing process may also be included. In some examples, the thermal degreasing process is accomplished under a wet hydrogen atmosphere. Therefore, the phenomena of incomplete removal and residual carbon caused by too fast reaction of organic components can be effectively prevented, and the defects of air holes, cracking, deformation and the like in the formed ceramic substrate 1 are effectively avoided.

In the present embodiment, a heat-insulating process after sintering may be further included in order to ensure the airtightness of the ceramic substrate 1 after sintering. Furthermore, the bonding strength between the ceramic substrate 10 and the feedthrough electrode 20 and the covering pad in the ceramic substrate 1 can be enhanced by appropriately extending the heat retention time, and the sintering density of the ceramic substrate 1 can be improved.

In addition, in the present embodiment, the ceramic substrate 1 may be formed by other methods, such as vacuum forming. Therefore, the process requirements under different conditions can be met.

In addition, in the present embodiment, the thickness of each ceramic sheet, for example, the ceramic sheets 110 to 140 is not particularly limited. In some examples, the thicknesses of the ceramic sheets 110 to 140 may be 0.05mm or more and 0.35mm or less, respectively, so as to be easy to process and have a good punching forming effect. In general, when the thickness of the ceramic sheet is too small, for example, less than 0.05mm, the processing is inconvenient because of its small thickness; when the thickness of the ceramic sheet is too large, for example, more than 0.35mm, the punching effect is poor due to the large thickness.

Additionally, in some examples, as shown in fig. 1, the ceramic substrate 10 may be in the shape of a generally cylindrical body. In the present embodiment, the shape of the ceramic substrate 10 is not particularly limited, and may be other regular shapes such as a cube, an elliptical cylinder, a triangular prism, and the like, or may be irregular shapes (including a combination of regular shapes and irregular shapes). Therefore, the requirements of different implanted medical devices on the shape of the ceramic substrate 1 can be met.

In the present embodiment, each of the ceramic sheets constituting the ceramic substrate 10 may have a plurality of through-holes 111 thereon. As shown in fig. 1 and 2, the ceramic sheet 110 may have a plurality of through-holes 111. In addition, the ceramic sheet 120, the ceramic sheet 130, or the ceramic sheet 140 may each have a plurality of through holes 111. For convenience of illustration, the illustration of the through-hole 111 of the ceramic sheet 120, the ceramic sheet 130, or the ceramic sheet 140 is omitted.

In addition, in the present embodiment, the ceramic sheet may have upper and lower surfaces, and the through-hole 111 may penetrate the upper and lower surfaces of the ceramic sheet. In this case, the ceramic substrate 1 fed through can be obtained.

In some examples, the arrangement of the through holes 111 on each ceramic sheet may be the same. In some examples, the respective through holes 111 between adjacent ceramic sheets may be arranged to intercommunicate up and down. Thereby, it is possible to cause feed-through electrodes 20 (described later) to penetrate through the respective through holes 111 (see fig. 3) at the same positions between the adjacent ceramic sheets. The bonding between the ceramic substrate 10 and the feed-through electrode 20 can thereby be made tighter, and the gas tightness of the ceramic substrate 1 can be improved.

In other examples, the arrangement of the through holes 111 may be different on each ceramic sheet. For example, the through holes 111 between adjacent ceramic sheets may be arranged in a staggered manner. Thereby, the respective feedthrough electrodes 20 (described later) filling the respective through holes 111 between the adjacent ceramic sheets can be arranged with being staggered, so that the running path of the hermetic leakage is effectively blocked or extended, and the hermetic property of the ceramic substrate 1 can be effectively improved.

In the present embodiment, the arrangement shape of the through holes 111 is not particularly limited. In some examples, as shown in fig. 2, the vias 111 may be arranged in a regular shape, such as an octagonal array. In other examples, the through holes 111 may be arranged in other regular shapes, such as square, circle, etc., and may also be arranged in irregular shapes (including a combination of regular and irregular shapes).

In the present embodiment, the shape of the through hole 111 is not particularly limited. In some examples, as shown in fig. 2, the shape of the through-hole 111 may be a regular shape such as a cylinder. In other examples, the shape of the through hole 111 may also be other regular shapes such as a cube, an elliptical cylinder, a triangular prism, etc., and may also be irregular shapes (including a combination of regular shapes and irregular shapes).

In the present embodiment, the hole diameter and the hole pitch of the through-hole 111 are not particularly limited. In some examples, the aperture diameter of the through-holes 111 may be 50 μm to 500 μm, and the pitch between the through-holes 111 (hole pitch) may be not less than 25 μm to 500 μm. In this case, the ceramic substrate 1 can be formed to satisfy the requirements of miniaturization and high integration density, and can be used, for example, as a ceramic substrate for an implantable medical device.

The number of the through holes 111 is not particularly limited, and may be determined according to specific needs, and for example, the number of the through holes 111 may be 1, or 2 or more.

In some examples, feed-through electrodes 20 may extend through the upper and lower surfaces of the ceramic substrate. Specifically, as shown in fig. 3 and 4, feed-through electrodes 20 may penetrate through the upper and lower surfaces of

ceramic sheets

110, 120, 130, and 140. In other examples, feed-through electrodes 20 are arranged offset on each ceramic sheet, and in particular, as shown in fig. 5 and 6, feed-through electrodes 20 may include feed-through electrodes 21 in ceramic sheet 110, feed-through electrodes 22 in ceramic sheet 120, feed-through electrodes 23 in ceramic sheet 130, and feed-through electrodes 24 in ceramic sheet 140.

In addition, in the present embodiment, when the respective through holes 111 between the adjacent ceramic sheets are arranged with being shifted, the ceramic substrate 1 may further include a wiring conductor 30 (described later). The feed-through electrodes 20 of adjacent ceramic sheets may communicate via wiring conductors 30 (described later), forming a conductive electrical connection. This can improve the electrical properties of the ceramic substrate 1. Specifically, as described in fig. 5 and 6, the wiring conductor 30 may include a wiring conductor 31, a wiring conductor 32, and a wiring conductor 33. Feed-through electrode 21, feed-through electrode 22, feed-through electrode 23, and feed-through electrode 24 may form a conductive electrical connection via wiring conductor 31, wiring conductor 32, and wiring conductor 33 in that order.

In addition, in the present embodiment, the wiring conductor 30 may form a wiring pattern between the respective ceramic sheets, and the feed-through electrodes 20 located on the adjacent ceramic sheets are connected via the wiring conductor 30. This makes it possible to form the ceramic substrate 1 electrically connected, thereby improving the electrical properties of the ceramic substrate 1.

In the present embodiment, the shape of the wiring pattern is not particularly limited. In some examples, the wiring pattern may be a regular shape such as a straight line, an S-shape, a U-shape, or the like, or may be an irregular shape (including a shape in which a regular shape and an irregular shape are combined). Therefore, different requirements of different application environments can be met.

In the present embodiment, the wiring conductor 30 can be designed to have a plurality of wiring patterns between the respective ceramic sheets. Thereby realize feed-through electrode 20's multiple different connected mode, further improve ceramic substrate 1's electrical property, the range of application is wider, can satisfy for example in the medical treatment implanted medical instrument to ceramic substrate 1 promoting functional requirement day by day, can also avoid inserting the adverse effect of external wire etc. to ceramic substrate 1's gas tightness.

In addition, in the present embodiment, the pattern may be prepared by a physical or chemical method such as coating or deposition (e.g., physical deposition or chemical deposition). In some examples, the wiring pattern may be prepared by a screen printing method. Therefore, the wiring pattern can be made more efficiently and conveniently, and the structure of the obtained wiring pattern is more accurate, so that the accuracy of the wiring pattern setting is improved, and the practicability of the ceramic substrate 1 is improved.

In the present embodiment, the size of the wiring conductor 30 is not particularly limited. In some examples, the wiring conductor 30 may have a size of 0.01mm to 0.1mm, whereby both electrical continuity of the wiring conductor 30 to the feedthrough electrode 20 can be achieved and damage such as cracking due to excessive stress can be effectively avoided.

In the present embodiment, the wiring conductor 30 may be formed by firing the third conductive paste. In some examples, the third conductive paste fired to form the wiring conductor 30 may be composed of a metal paste. For example, the third conductive paste may be composed of one or more selected from among a tungsten paste, a molybdenum-manganese paste, a silver paste, a gold paste, or a platinum paste. Preferably, the third conductive paste may be composed of a platinum paste. Therefore, the fired wiring conductor 30 can have a smaller resistance and be more matched with the performance parameters of the ceramic substrate 10, so that the connection strength between the wiring conductor 30 and the ceramic substrate 10 is higher, the electrical performance of the ceramic substrate 1 can be effectively improved, and the long-term reliability of the ceramic substrate is further improved.

In addition, in the present embodiment, the third conductive paste constituting the wiring conductor 30 may further include an inorganic component (e.g., glass frit) and an organic dielectric component. Thereby, it is possible to facilitate control of the sintering behavior of a metal slurry such as a platinum slurry to be formed closer to that of the ceramic substrate 10, thereby avoiding occurrence of structural defects such as cracks or delamination.

In the present embodiment, the ceramic substrate 10 may have an upper surface 10a and a lower surface 10b (see fig. 4 or 6). In some examples, the upper surface 10a of the ceramic substrate 10 and the lower surface 10b of the ceramic substrate 10 may be relatively parallel. In addition, in some examples, as shown in fig. 4, upper surface 10a of ceramic substrate 10 and lower surface 10b of ceramic substrate 10 may be electrically connected by feed-through electrode 20.

In addition, in some examples, as shown in fig. 6, the upper surface 10a of the ceramic substrate 10 and the lower surface 10b of the ceramic substrate 10 may be electrically connected via the feed-through electrode 20 and the wiring conductor 30. That is, the upper surface 10a and the lower surface 10b of the ceramic substrate 10 may form a conductive path via the feed-through electrode 20 and the wiring conductor 30. Thereby, the electronic component on the upper surface 10a side and the electronic component on the lower surface 10b side can be electrically connected via the feedthrough electrode 20 and the wiring conductor 30.

One example of the conductive paths formed by the upper surface 10a and the lower surface 10b of the ceramic substrate 10 is described below with reference to fig. 6. As shown in fig. 6, the ceramic substrate 10 may be composed of four

ceramic sheets

110, 120, 130, and 140, as an example. The upper surface 10a of the ceramic substrate 10 is the upper surface of the ceramic sheet 110. The lower surface 10b of the ceramic substrate 10 is the lower surface of the ceramic sheet 140. Feed-through electrode 20 may include feed-through electrode 21, feed-through electrode 22, feed-through electrode 23, and feed-through electrode 24. The wiring conductor 30 may include a wiring conductor 31, a wiring conductor 32, and a wiring conductor 33.

Specifically, in the ceramic substrate 10, the feed-through electrode 21 may be connected to the feed-through electrode 22 via the wiring conductor 31, thereby electrically connecting the ceramic sheet 110 to the ceramic sheet 120. In addition, feed-through electrode 22 may be connected to feed-through electrode 23 via wiring conductor 32, thereby conductively connecting ceramic sheet 120 to ceramic sheet 130. Furthermore, feed-through electrode 23 can be connected to feed-through electrode 24 via wiring conductor 33, so that ceramic sheet 130 is connected to ceramic sheet 140 in an electrically conductive manner. Thereby, the upper surface 10a and the lower surface 10b of the ceramic substrate 10 are brought into conductive connection by the

feedthrough electrodes

21, 22, 23, 24, 31, 32, and 33.

In this embodiment, feed-through electrode 20 may be fired from a first conductive paste. In some examples, the first conductive paste may be co-fired with the ceramic sheets 110 to 140 at a temperature of 1450 ℃ to 1600 ℃. Thus, the fired feed-through electrode 20 can be bonded to the ceramic substrate 10, thereby avoiding techniques such as welding between ceramic and metal, simplifying the process, and further improving the airtightness and long-term reliability of the ceramic substrate 1.

In the present embodiment, the first conductive paste fired to form feed-through electrode 20 may be composed of a metal paste. In some examples, the first conductive paste may be composed of one or more selected from among a tungsten paste, a molybdenum-manganese paste, a silver paste, a gold paste, or a platinum paste. Preferably, the first conductive paste may be composed of a platinum paste. Accordingly, the fired feed-through electrode 20 can have a smaller resistance, and is more matched with the performance parameters of the ceramic substrate 10, so that the connection strength between the feed-through electrode 20 and the ceramic substrate 10 is higher, and the long-term reliability of the ceramic substrate 1 can be effectively improved.

In addition, in the present embodiment, the first conductive paste constituting the feed-through electrode 20 may further include an inorganic component (e.g., glass frit) and an organic dielectric component. Thereby, it is possible to facilitate control of the sintering behavior of a metal slurry such as a platinum slurry to be formed closer to that of the ceramic substrate 10, thereby avoiding occurrence of structural defects such as cracks or delamination.

In addition, in the present embodiment, the first conductive paste constituting the feed-through electrode 20 may be filled in the through-hole 111 of each ceramic sheet by screen printing, transfer, or the like. In this case, it is possible to more efficiently and easily fabricate the feed-through electrode 20 and to make the size and structure of the resulting feed-through electrode 20 more precise.

In the present embodiment, the first conductive paste constituting the feed-through electrode 20 may completely fill the through-holes 111 of the respective ceramic sheets, or may partially fill the through-holes, as long as the feed-through electrode 20 can penetrate the upper and lower surfaces of the respective ceramic sheets. Therefore, the adjustment can be carried out according to the requirements of parameters such as shrinkage performance of the ceramic sheet or the first conductive paste, and different requirements under different conditions are met.

In addition, in the present embodiment, the shape, size, arrangement, and the like of the feedthrough electrode 20 can be kept consistent with the through-hole 111. Therefore, the ceramic substrate 1 can be formed, thereby improving the airtightness of the ceramic substrate 1.

In the present embodiment, a cover pad (not shown) may be provided on an outer surface of the ceramic substrate 10 (for example, the upper surface 10a of the ceramic substrate 10 or the lower surface 10b of the ceramic substrate 10). A cover pad may overlie the feedthrough electrode 20. Based on the above description, ceramic substrate 10 may include a plurality of ceramic sheets, and a cover pad may be disposed over feed-through electrode 20 of the outermost ceramic sheet. This makes it possible to easily bond (e.g., solder) an external electronic component to the ceramic substrate via the cover pad, thereby forming an electrical connection.

Additionally, in some examples, the size of the cover pad is larger than the size of the feedthrough electrode 20. I.e., the cross-sectional area of the cover pad is greater than the cross-sectional area of the feed-through electrode 20. In this case, a tight bond can be formed between the cover pad and the feed-through electrode 20 and the ceramic base 10, so that the airtightness of the ceramic substrate 1 can be further improved. Of course, the size of the cover pad may also be smaller than or equal to the size of the feed-through electrode 20, so that different requirements under different conditions may be met.

In some examples, the cover pad may completely cover the feed-through electrode 20. Thereby, a tight bond can be formed between the cover pad and the feed-through electrode 20 and the ceramic base 10, and the airtightness of the ceramic substrate 1 can be further improved. In other examples, the cover pad may partially cover the feed-through electrode 20. Reliable electrical connections can also be made between the cover pads and the feed-through electrodes 20 and the ceramic substrate 10.

In this embodiment, the cover pad may be formed of the second conductive paste. In some examples, the second conductive paste is different from the first conductive paste, and the second conductive paste may be composed of one or more selected from among a tungsten paste, a molybdenum-manganese paste, a silver paste, a gold paste, or a platinum paste. In this case, the airtightness of the ceramic substrate 1 can be improved.

In some examples, the composition of the second conductive paste may be a mixture of a ceramic material and a metallic material. The ceramic material is the same material (for example, alumina) as that of each of the

ceramic sheets

110, 120, 130 and 140, and the metal material is one or more materials (for example, platinum) selected from tungsten, molybdenum, manganese, silver, gold, platinum and alloys thereof. In this case, the covering pad formed of the second conductive paste is matched in one aspect to the performance parameters of the ceramic substrate 10, thereby making it stronger in connection with the ceramic substrate 10; the cover pad, on the other hand, is matched to the performance parameters of feedthrough electrode 20, making it more robust to connection with feedthrough electrode 20. In this case, the airtightness of the ceramic substrate 1 can be further improved, and the electrical performance and long-term reliability of the ceramic substrate 1 can be further improved.

In some examples, the second conductive paste may be composed to include a metal material and an inorganic component. The metal material is composed of one or more materials (such as platinum) of tungsten, molybdenum-manganese, silver, gold, platinum and their alloys. Inorganic components such as glass frit and organic medium components.

The mixing ratio of the ceramic material and the metal material in the covering pad is not particularly limited, that is, the ratio of the ceramic material and the metal material can be adjusted according to the actual requirement of the product. In some examples, the proportion of the ceramic material may be greater than the proportion of the metal material, so that the matching degree of the covering gasket and the ceramic base 10 may be improved, thereby improving the force strength of the connection of the two to further improve the gas tightness of the ceramic substrate 1.

In addition, in the present embodiment, the ceramic substrate 1 may include co-firing each ceramic sheet with the first conductive paste and the second conductive paste at a temperature of 1450 ℃ to 1600 ℃, and in the co-firing, the ceramic paste is coated between the ceramic base and the feedthrough electrode.

In some examples, the ceramic slurry may be comprised of alumina. The ceramic slurry composition may be the same as the material composition of each of the ceramic sheets described above. For example, the ceramic slurry and the ceramic sheet may be different kinds of ceramics. The ceramic slurry and the ceramic sheet may be the same kind of ceramic. For example, the ceramic slurry and the ceramic sheet may be composed of the same ceramic but with different contents of the components. The ceramic slurry and the ceramic sheet may also be composed of the same ceramic and have the same content of each component.

In the present embodiment, during the co-firing process, the ceramic slurry in a molten state can penetrate into the gap between the ceramic substrate 10 and the feed-through electrode 20, improving the airtightness between the ceramic substrate 10 and the feed-through electrode 20.

In some examples, when the arrangement of the respective through holes 111 is different on the respective ceramic sheets, the wiring conductor 30 exists between the adjacent ceramic sheets, in which case the respective ceramic sheets are co-fired with the first conductive paste, the second conductive paste, and the third conductive paste at a temperature of 1450 ℃ to 1600 ℃, and in the co-firing, the ceramic paste is coated between the ceramic substrate and the feedthrough electrode. For example, the third conductive paste may be co-fired with the first conductive paste, the second conductive paste, and the ceramic sheets 110 to 140 at a temperature of 1450 ℃ to 1600 ℃. The feed-through electrode 20 and the wiring conductor 30 formed by firing the first conductive paste and the third conductive paste are more matched with the performance parameters of the ceramic substrate 10, the connection structure strength is higher, and the electrical performance of the ceramic substrate can be improved, and the long-term reliability of the ceramic substrate can be further improved. The first conductive paste and the third conductive paste may be made of platinum. In this case, the feed-through electrodes and the wiring conductors are uniformly made of platinum, and this uniformity can improve the conduction efficiency, improve the conduction, and the like, thereby further improving the electrical performance and long-term reliability of the ceramic substrate. The wiring conductor 30 formed by firing can be bonded with the ceramic substrate 10 into a whole, thereby avoiding techniques such as welding of ceramic and metal and simplifying the process.

In the present embodiment, the ceramic substrate 1 may include a connection layer (not shown). The plating method includes but is not limited to soldering. Thus, the connection layer can further enhance the connection (e.g., soldering) performance of the ceramic substrate 1, and enhance the reliability of the electrical connection between the ceramic substrate 1 and the external electronic component. The connection layer may also be referred to as a protection layer. The connecting layer may partially or completely cover the covering mat.

In this embodiment, the connection layer is formed of a fourth conductive paste, and the fourth conductive paste may be formed of one or more materials selected from tungsten, molybdenum, manganese, silver, gold, platinum, nickel, and an alloy thereof. This improves the electrical conductivity of the connection layer, thereby improving the electrical performance of the ceramic substrate 1. In some examples, the connection layer may be a nickel layer and a gold layer. Therefore, different application requirements of the implantable medical device can be met.

In the present embodiment, as shown in fig. 1, the input and output terminals of the ceramic substrate 1 may be connected to other members via connecting wires (not shown), and the connecting wires may be connected to the ceramic substrate 1 by welding (e.g., soldering) or the like. This enables the ceramic substrate 1 to realize signal interaction with other functional components.

Fig. 7 is a flowchart showing a manufacturing process of the ceramic substrate according to the embodiment of the present invention. The method for manufacturing the ceramic substrate 1 according to the present embodiment will be described in detail below with reference to fig. 7.

In the present embodiment, the method of manufacturing a ceramic substrate includes preparing a plurality of ceramic sheets, and forming a plurality of through holes in each ceramic sheet (step S10); filling a first conductive paste as a feed-through electrode in each through hole of each ceramic sheet (step S20); forming a covering bottom pad covering the feed-through electrode on an outer surface of the outermost ceramic sheet using a second conductive paste (step S30); the respective ceramic sheets are sequentially laminated, and the respective ceramic sheets are co-fired together with the first conductive paste and the second conductive paste at a temperature of 1450 ℃ to 1600 ℃, in which the ceramic paste is applied between the plurality of ceramic sheets and the first conductive paste (step S40).

In the present embodiment, step S10 may include preparing a die having a plurality of guide pillars and ceramic powder for manufacturing each ceramic sheet. In some examples, the number of dies may be two or more, and the distribution of the plurality of guide posts on different dies may be the same. Therefore, the through holes 111 on different prepared ceramic sheets can be arranged in the same way, for example, in an up-and-down mutual arrangement. In other examples, the number of dies may be two or more, and the plurality of guide posts on different dies may be distributed differently, such as staggered. Thus, the through holes 111 can be arranged differently, for example, staggered, on different ceramic sheets to be prepared.

In addition, in some examples, the mold may have a substantially cylindrical shape, but the shape of the mold is not particularly limited, and it may also have other regular shapes such as a cube, an elliptical cylinder, a triangular prism, and the like, and may also have an irregular shape (including a shape in which a regular shape and an irregular shape are combined). Thus, various ceramic sheets (such as

ceramic sheets

110, 120, 130, and 140) of different shapes can be formed, so as to meet the requirements of different implantable medical devices on the shape of the ceramic substrate 1. In addition, the number of the dies may be two or more, whereby a multilayer (i.e., a plurality or a plurality of pieces) ceramic sheet, for example, four-layer ceramic sheet, i.e., ceramic sheet 110, ceramic sheet 120, ceramic sheet 130, and ceramic sheet 140, can be prepared. However, the present embodiment is not limited thereto, i.e., it may be made up of another number of ceramic sheets, as a matter of course. Therefore, the ceramic substrate layer with the thickness less than or greater than four can be arranged according to different application requirements, and the requirements of different implantable medical devices on the structure of the ceramic substrate 1 can be met.

In the present embodiment, in step S10, the molds may be two or more and have the same guide post distribution. Therefore, the ceramic sheets with the same through hole 111 distribution can be prepared, and the through holes 111 of the adjacent ceramic sheets are distributed in an up-and-down communication manner.

In some examples, in step S10, the mold may be two or more and have different guide post distributions, and the guide posts may be different in size. Therefore, ceramic sheets with different through hole 111 distributions can be prepared, and the staggered distribution of the through holes 111 of the adjacent ceramic sheets is realized; and ceramic sheets with different pore diameters and pore distances can be obtained, so that different requirements on the ceramic sheets under different conditions can be met.

In addition, in the present embodiment, although the shape of the guide post is a cylindrical shape in step S10, the shape of the guide post is not particularly limited. It may have other regular shapes such as a cube, an elliptical cylinder, a triangular prism, etc., or may have an irregular shape (including a combination of regular and irregular shapes), so that through holes 111 having different shapes may be formed.

In addition, in the present embodiment, in step S10, the diameter of the guide posts is not particularly limited, and for example, the diameter thereof may be at least 0.05mm, and the distance between the guide posts may be at least 0.25mm, so that the through holes 111 formed thereby may be directly and optimally spaced from each other, so that the ceramic substrate 1 may satisfy the requirements of miniaturization and high integration density, may replace the existing ceramic substrate for the implantable medical device, and may be manufactured at a low cost.

In addition, in the present embodiment, in step S10, the arrangement of the guide pillars is not particularly limited. They may be arranged in regular shapes such as an octagonal array as shown in fig. 2, or in other irregular shapes such as a hollow array.

In addition, in the present embodiment, the total number of the guide pillars is 267 in step S10, but the number of the guide pillars is not particularly limited, and may be determined according to the specific requirements of the number of the through holes 111 in the

ceramic sheets

110, 120, 130, and 140, and for example, the number of the through holes 111 may be 1, or 2 or more.

In this embodiment, step S10 may include filling a mold with ceramic powder. In some examples, the ceramic powder is composed of alumina ceramic having a content of not less than 99.99%. Thus, each of the ceramic sheets prepared can be made of alumina ceramic having a content of not less than 99.99%. Generally, in each ceramic sheet, alumina (Al) is attached to₂O₃) The increase in mass fraction increases the main crystal phase, and the physical properties of each ceramic sheet are gradually improved, such as pre-compression strength, bending strength, and elastic modulus, and thus it is considered that better biosafety and long-term reliability are exhibited.

In the present embodiment, in step S10, the ceramic powder may be press-molded by using a mold to form each ceramic sheet, and each ceramic sheet has a plurality of through holes 111. In some examples, the through holes 111 between adjacent ceramic sheets on the ceramic sheets 110 to 140 are arranged to communicate up and down. Thereby, the feed-through electrodes 20 can be made to penetrate through the through-holes 111 of the adjacent ceramic sheets in the same position. This can improve the airtightness of the ceramic substrate 1.

In other examples, the through holes 111 between adjacent ceramic sheets on the ceramic sheets 110 to 140 are staggered. This makes it possible to stagger the arrangement of the feed-through electrodes 20 filling the adjacent ceramic sheet layers. In this case, the traveling path of the hermetic leakage can be effectively blocked or extended, so that the hermetic performance of the ceramic substrate 1 can be effectively improved. However, the present embodiment is not limited to this, and for example, the respective ceramic sheets (for example, the

ceramic sheets

110, 120, 130, and 140) may be formed by another method such as firing.

In addition, in some examples, the ceramic powder may completely fill the mold or partially fill the mold, so that different requirements for each formed ceramic sheet (e.g., ceramic sheet 110, ceramic sheet 120, ceramic sheet 130, and ceramic sheet 140) under different conditions may be met.

In the present embodiment, step S20 may include preparing a first conductive paste, and filling each via hole 111 of each ceramic sheet with the first conductive paste. The first conductive paste may be fired to form the feed-through electrode 20. In some examples, the first conductive paste may be composed of one or more selected from among a tungsten paste, a molybdenum-manganese paste, a silver paste, a gold paste, or a platinum paste. Preferably, the first conductive paste may be composed of a platinum paste. Accordingly, the feed-through electrode 20 formed by firing the first conductive paste can have a smaller resistance, and is more matched with the performance parameters of the ceramic substrate 10, so that the connection strength between the feed-through electrode 20 and the ceramic substrate 10 is higher, and the long-term reliability of the ceramic substrate 1 can be effectively improved.

In addition, in the present embodiment, in step S20, the first conductive paste may be filled in the through-holes 111 of the respective ceramic sheets by screen printing, transfer printing, or the like. In this case, it is possible to more efficiently and easily fabricate the feed-through electrode 20 and to make the size and structure of the resulting feed-through electrode 20 more precise.

Additionally, in some examples, step S30 may include preparing a second conductive paste and overlaying the second conductive paste on the feed-through electrodes on the outer surface of the outermost ceramic sheet. Namely, the second conductive paste is covered on the first conductive paste on the outer surface of the outermost ceramic sheet. In addition, the second conductive paste may form a covering pad covering feed-through electrode 20 on the outer surface of the outermost ceramic sheet. That is, the second conductive paste is provided on the outer surface of the outermost ceramic sheet (e.g., the ceramic sheet 110 or the ceramic sheet 140), and the second conductive paste is coated on the first conductive paste of the through-hole 111 in the ceramic sheet to form a coating pad. This makes it possible to easily bond (e.g., solder) an external electronic component to the ceramic substrate 1 via the cover pad, thereby forming an electrical connection. In some examples, the covering pad formed by the second conductive paste may completely cover or partially cover the feed-through electrode 20. Thereby, a tight bond can be formed between the cover pad and the feed-through electrode 20 and the ceramic base 10, and the airtightness of the ceramic substrate 1 can be further improved.

In some examples, the cover pad may be formed to have a size larger than that of the feed-through electrode 20, in which case a tight bond may be formed between the cover pad and the feed-through electrode 20 and the ceramic base 10, so that the airtightness of the ceramic substrate 1 may be further improved. Of course, the size of the cover pad may also be smaller than or equal to the size of the feed-through electrode 20, so that different requirements under different conditions may be met.

In addition, in some examples, the second conductive paste may be composed of one or more selected from among a tungsten paste, a molybdenum-manganese paste, a silver paste, a gold paste, or a platinum paste. Therefore, the covering pad formed by firing the second conductive paste can be more matched with the performance parameters of the ceramic substrate 10, the connection structure strength is higher, the electrical performance of the ceramic substrate 1 can be improved, and the long-term reliability of the ceramic substrate can be further improved. The second conductive paste may further include inorganic components such as glass frit and organic dielectric components.

In other examples, the composition of the second conductive paste may be a mixture of a ceramic material and a metal material. The ceramic material is the same material (e.g., alumina) as that of each of the ceramic sheets (e.g., the

ceramic sheets

110, 120, 130, and 140), and the metal material is one or more materials (e.g., platinum) selected from tungsten, molybdenum, manganese, silver, gold, platinum, and alloys thereof. In this case, the covering pad formed of the second conductive paste is matched in one aspect to the performance parameters of the ceramic substrate 10, thereby making it stronger in connection with the ceramic substrate 10; the cover pad, on the other hand, is matched to the performance parameters of feedthrough electrode 20, making it more robust to connection with feedthrough electrode 20. In this case, the airtightness of the ceramic substrate 1 can be further improved, and the electrical performance and long-term reliability of the ceramic substrate 1 can be further improved. In addition, the mixing ratio of the ceramic material and the metal material in the second conductive paste is not particularly limited, that is, the ratio of the ceramic material and the metal material can be adjusted according to the actual needs of the product.

In addition, in some examples, when the feed-through electrodes 20 of adjacent ceramic sheet layers are arranged in a staggered manner, in step S30, forming a prescribed wiring pattern on each ceramic sheet using the third conductive paste as the wiring conductor 30 may be further included. In some examples, the third conductive paste may be composed of one or more selected from among a tungsten paste, a molybdenum-manganese paste, a silver paste, a gold paste, or a platinum paste. Preferably, the third conductive paste may be composed of a platinum paste. Therefore, the wiring conductor 30 formed by firing the third conductive paste can have a smaller resistance and be more matched with the performance parameters of the ceramic substrate 10, so that the connection strength between the wiring conductor 30 and the ceramic substrate 10 is higher, and the long-term reliability of the ceramic substrate 1 can be effectively improved.

In addition, in this embodiment mode, inorganic components such as glass frit and organic dielectric components may be further included in the first conductive paste and the third conductive paste. Thereby, the sintering behavior of the metal slurry, such as a platinum slurry, can be controlled to be close to that of the ceramic substrate 10, thereby preventing the occurrence of structural defects such as cracks or delamination.

In addition, in some examples, in step S30, the shape of the wiring pattern is not particularly limited. In some examples, the wiring pattern may be a regular shape such as a straight line, an S-shape, a U-shape, or the like, or may be an irregular shape (including a shape in which a regular shape and an irregular shape are combined). Therefore, different requirements of different application environments can be met.

In addition, in some examples, in step S30, the wiring conductor 30 may also be designed to form multiple wiring patterns simultaneously between the respective ceramic sheets. Thereby realize the multiple different connected mode of electrode 20 of feeding through, further improve ceramic substrate 1's electrical property, the range of application is wider, can satisfy among the medical implanted medical instrument to ceramic substrate 1 functional requirement that promotes day by day, can also avoid inserting the adverse effect of external wire etc. to ceramic substrate 1's gas tightness.

In addition, in some examples, in step S30, the pattern of the pattern may be prepared by a physical or chemical method, such as coating, deposition, or etching (tch) (e.g., physical deposition or chemical deposition). In some examples, the wiring pattern may be prepared by a screen printing method. Therefore, the wiring pattern can be made more efficiently and conveniently, and the structure of the obtained wiring pattern is more accurate, so that the accuracy of the wiring pattern setting is improved, and the practicability of the ceramic substrate 1 is improved.

In the present embodiment, the size of the wiring conductor 30 in step S30 is not particularly limited. In some examples, the wiring conductor 30 may have a size of 0.01mm, so that both electrical continuity between the wiring conductor 30 and the feedthrough electrode 20 can be achieved, and damage such as cracking due to excessive stress can be effectively avoided.

In this embodiment, step S40 may include stacking the ceramic sheets one on another. In some examples, the ceramic sheets may include four, for example, ceramic sheets 110 through 140. However, the present embodiment is not limited thereto, and the number of ceramic sheets constituting the ceramic substrate 10 is not particularly limited, and may be, for example, two, three, or five or more ceramic sheets. Therefore, the ceramic sheet layers smaller than or larger than four can be arranged according to different application requirements, and the requirements of different implantable medical devices on the structure of the ceramic substrate 1 can be met.

In some examples, when the plurality of guide pillars in step S10 are equally distributed, step S40 may include penetrating the feed-through electrode 20 through the upper and lower surfaces of the ceramic substrate. In other examples, when the plurality of guide posts in step S10 are not distributed differently, step S40 may include connecting the feed-through electrodes 20 of adjacent ceramic sheets via the wiring conductors 30. This makes it possible to form the ceramic substrate 1 electrically connected, thereby improving the electrical properties of the ceramic substrate 1.

In the present embodiment, in step S40, co-firing the ceramic sheet together with the first conductive paste and the second conductive paste at a temperature of 1450 ℃ to 1600 ℃. In some examples, each ceramic sheet 110 to 140 may be at 1450 ℃ to 1600 ℃, preferably 1550 ℃ to 1600 ℃.

Generally, the firing temperature of the existing high-purity alumina ceramics (the content is more than 99.9%) needs to be as high as 1680 ℃ to 1990 ℃. In contrast, in the present embodiment, by controlling the firing temperature at 1450 ℃ to 1600 ℃, preferably at 1550 ℃ to 1600 ℃ as described above, on the one hand, both firing molding of the metal (feed-through electrode 20 and cover pad) and firing molding of the ceramic (ceramic substrate 10) can be satisfied; on the other hand, low-temperature co-firing of the ceramic sheet (forming the ceramic substrate 10) and the conductive paste (forming the feed-through electrode 20 and the cover pad) can be achieved, so that the bonding strength of the fired ceramic substrate 10 with the feed-through electrode 20 and the cover pad (not shown) is improved, the preparation efficiency of the ceramic substrate 1 is effectively improved, and the production cost of the ceramic substrate 1 is reduced.

In other examples, by controlling the firing temperature at 1450 ℃ to 1600 ℃, preferably at 1550 ℃ to 1600 ℃ as described above, on the one hand, it is possible to satisfy both the firing of the metal (the feedthrough electrode 20, the covering pad, and the wiring conductor 30) and the ceramic (the ceramic substrate 10); on the other hand, low-temperature co-firing of the ceramic sheet (forming the ceramic substrate 10) and the conductive paste (the feed-through electrode 20, the cover pad, and the wiring conductor 30) can be achieved, so that the bonding strength of the fired ceramic substrate 10 with the feed-through electrode 20 and the cover pad is improved, the preparation efficiency of the ceramic substrate 1 is effectively improved, and the production cost of the ceramic substrate 1 is reduced.

In addition, in consideration of the difference in expansion index between the ceramic sheet and the metal material, in the present embodiment, a low-temperature preheating step may be further included in step S40. In some examples, pre-bonding of the ceramic (ceramic substrate 10) to the metal (feedthrough electrode 20 and cover pad) may be done at a lower temperature (e.g., below 500 ℃) to prevent warping, cracking, etc., from occurring due to too high a co-firing temperature or too fast a co-firing rate. In other examples, pre-bonding of the ceramic (ceramic substrate 10) and the metal (feedthrough electrode 20, cover pad, and wiring conductor 30) may be done at a lower temperature (e.g., below 500 ℃) to prevent delamination, cracking, etc., caused by too high a co-firing temperature or too fast a co-firing rate.

Generally, when the heating rate is too fast, the ceramic substrate is prone to have gas or incomplete sintering; the heating rate is too slow, which prolongs the sintering process time, reduces the manufacturing efficiency and increases the manufacturing cost. Therefore, in the present embodiment, in step S40, the method may further include controlling a temperature increase rate in the co-firing process. Therefore, the phenomenon of incomplete gas or sintering in the ceramic substrate 1 can be prevented, the density of the ceramic substrate 1 is ensured, the preparation efficiency of the ceramic substrate 1 can be effectively improved, and the production cost of the ceramic substrate 1 is reduced.

In addition, it is considered that a certain amount of organic components and binder phase may be added during the preparation of the ceramic substrate 1. In the present embodiment, in step S40, a thermal degreasing process may be further included. In some examples, the thermal degreasing process is accomplished under a wet hydrogen atmosphere. Therefore, the phenomena of incomplete removal and residual carbon caused by too fast reaction of organic components can be effectively prevented, and the defects of air holes, cracking, deformation and the like in the formed ceramic substrate 1 are effectively avoided.

In this embodiment, in step S40, a heat-insulating process after sintering may be further included in order to ensure the airtightness of the ceramic substrate 1 after sintering. Further, by appropriately extending the heat retention time, the bonding strength between the ceramic base 10 and the feedthrough electrode 20 and the covering backing (not shown) in the ceramic substrate 1 can be enhanced, and the sintering density of the ceramic substrate 1 can be improved. In other examples, by appropriately extending the soak time, the bonding strength of the ceramic substrate 10 to the feed-through electrode 20, the cover pad (not shown), and the wiring conductor 30 in the ceramic substrate 1 can be enhanced, and the sintering density of the ceramic substrate 1 can be improved.

In this embodiment, in step S40, the ceramic substrate 1 may be formed by other methods, such as vacuum forming. Therefore, the process requirements under different conditions can be met.

In some examples, in step S40, a ceramic slurry is applied between the plurality of ceramic sheets and the first conductive paste in co-firing. In some examples, the ceramic slurry may be comprised of alumina. The ceramic slurry composition may be the same as the material composition of each of the ceramic sheets described above. For example, the ceramic slurry and the ceramic sheet may be different kinds of ceramics. The ceramic slurry and the ceramic sheet may be the same kind of ceramic. For example, the ceramic slurry and the ceramic sheet may be composed of the same ceramic but with different amounts of the components. The ceramic slurry and the ceramic sheet may also be composed of the same ceramic and have the same content of each component.

In this embodiment, during the co-firing process, the ceramic slurry in a molten state can penetrate into the gap between the ceramic substrate and the feed-through electrode, improving the airtightness between the ceramic substrate and the feed-through electrode.

In addition, in some examples, the method of manufacturing the ceramic substrate may further include forming a connection layer on the cover pad using fourth conductive paste plating. The plating method includes but is not limited to soldering. Thus, the connection layer can further enhance the connection (e.g., soldering) performance of the ceramic substrate 1, and enhance the reliability of the electrical connection between the ceramic substrate 1 and the external electronic component. The fourth conductive paste may be made of one or more materials selected from tungsten, molybdenum, manganese, silver, gold, platinum, nickel, and alloys thereof. This improves the electrical conductivity of the connection layer, thereby improving the electrical performance of the ceramic substrate 1.

While the invention has been specifically described above in connection with the drawings and examples, it will be understood that the above description is not intended to limit the invention in any way. Those skilled in the art can make modifications and variations to the present invention as needed without departing from the true spirit and scope of the invention, and such modifications and variations are within the scope of the invention.

Claims

1. A ceramic substrate for an implantable medical device, comprising:

the method comprises the following steps:

a ceramic substrate formed by laminating and firing a plurality of ceramic sheets each having a plurality of through holes;

a feed-through electrode fired from a first conductive paste filling each of the vias;

a cover pad fired from a second conductive paste and covering the feed-through electrode of the outermost ceramic sheet; and

a wiring conductor formed by firing the third conductive paste, forming a wiring pattern between the respective ceramic sheets, and via which the feed-through electrodes located in the adjacent ceramic sheets are connected;

wherein each of the ceramic sheets is co-fired with the first and second conductive pastes at a temperature of 1450 ℃ to 1600 ℃, and in the co-firing, a ceramic paste in a molten state is coated between the ceramic substrate and the feedthrough electrode.

2. The ceramic substrate of claim 1, wherein:

the ceramic sheet is composed of alumina, and the mass fraction of the alumina in each ceramic sheet is 96% or more.

3. The ceramic substrate of claim 1, wherein:

the ceramic sheet has an upper surface and a lower surface, the upper surface and the lower surface being electrically connected via the feed-through electrode and the wiring conductor.

4. The ceramic substrate of claim 1, wherein:

the first conductive paste is composed of one or more selected from tungsten paste, molybdenum-manganese paste, silver paste, gold paste, or platinum paste.

5. The ceramic substrate of claim 1, wherein:

the second conductive paste is composed of one or more selected from tungsten paste, molybdenum-manganese paste, silver paste, gold paste, or platinum paste.

6. The ceramic substrate of claim 1, wherein:

the third conductive paste is composed of a metal paste, an inorganic component and an organic medium component.

7. The ceramic substrate of claim 1, wherein:

the through holes between adjacent ceramic sheets are arranged in a staggered manner.

8. The ceramic substrate of claim 7, wherein:

the aperture of the through hole is 50-500 micrometers.

9. A method for manufacturing a ceramic substrate for an implantable medical device, comprising:

the method comprises the following steps:

preparing a plurality of ceramic sheets and forming a plurality of through holes on each of the ceramic sheets;

filling a first conductive paste as a feed-through electrode in each of the through holes of each of the ceramic sheets;

forming a covering bottom pad covering the feed-through electrode on an outer surface of the outermost ceramic sheet using a second conductive paste, forming a predetermined wiring pattern on each of the ceramic sheets using a third conductive paste as a wiring conductor, and connecting the feed-through electrodes of the adjacent ceramic sheets via the wiring conductor; and is provided with

Sequentially laminating each of the ceramic sheets, and co-firing each of the ceramic sheets together with the first conductive paste and the second conductive paste at a temperature of 1450 ℃ to 1600 ℃, in which a ceramic paste in a molten state is coated between a plurality of ceramic sheets and the first conductive paste.

10. The manufacturing method according to claim 9, wherein:

11. The manufacturing method according to claim 9, wherein:

the first conductive paste and the second conductive paste are composed of one or more selected from tungsten paste, molybdenum-manganese paste, silver paste, gold paste, or platinum paste.

12. The manufacturing method according to claim 9, wherein:

and sequentially laminating the ceramic sheets, and pre-combining the ceramic sheets with the first conductive paste and the second conductive paste at a temperature of below 500 ℃.

13. The manufacturing method according to claim 9, wherein:

during the co-firing, the ceramic slurry penetrates into a gap between the ceramic substrate and the feedthrough electrode.