Methods for forming implantable devices

Abstract

A method for forming an implantable device, comprising: providing a body made of glass and provided with a feedthrough electrode, the body comprising a main body part adapted to provide a sealed cavity and an extension part extending outward from the main body part, the main body part comprising a cover part, a substrate part disposed opposite to the cover part, and a sidewall part located between the cover part and the substrate part; forming a sacrificial layer at least on the extension part; forming a first part of a flexible electrode on the main body part and a second part of the flexible electrode on the extension part; removing the sacrificial layer; folding the second part towards the first part to expose at least an interference region of the main body part; separating the extension part from the main body part; sealing a signal processing device into the cavity and electrically connecting the signal processing device with the flexible electrode through the feedthrough electrode. The implantable device prepared by the method of the present disclosure can realize signal interaction between the device inside the cavity and the external flexible electrode while ensuring the air tightness of the device inside the cavity and the long-term stability in the implanted environment.

Description

Technical Field

[0001] This invention relates to the field of brain-computer interface technology, and more specifically to a method for forming an implantable device. Background Technology

[0002] Brain-computer interface (BCI) refers to a direct connection created between the brain of a person or animal and an external device to enable information exchange between the brain and the device. Implantable devices achieve this by implanting a chip into the body and connecting it to brain cells via electrodes.

[0003] However, existing implantable devices generally only focus on how to achieve signal interaction, and their performance in terms of device airtightness and long-term stability in the implantation environment is unsatisfactory. Summary of the Invention

[0004] The technical problem solved by this invention is to provide an improved method for fabricating implantable devices, which can achieve signal interaction while ensuring that the implantable device maintains excellent device airtightness and long-term stability in the implantation environment.

[0005] To address the aforementioned technical problems, embodiments of the present invention provide a method for forming an implantable device, comprising: providing a body, the body being made of glass and having a feedthrough electrode, the body including a main body portion and an extension portion, the main body portion being adapted to provide a sealed cavity, the main body portion including a cover portion, a substrate disposed opposite to the cover portion, and a sidewall located between the cover portion and the substrate, the cover portion, the substrate, and the sidewall together forming the cavity, the extension portion extending outward from the main body portion; forming a sacrificial layer at least in the extension portion; forming a first portion of a flexible electrode in the main body portion, and forming a second portion of the flexible electrode in the extension portion, wherein a non-zero gap exists between the second portion and the extension portion; removing the sacrificial layer; folding the second portion toward the first portion to at least expose an interference region of the main body portion, wherein the projection of the interference region in a first direction at least covers the overlapping area of ​​the projection of the sidewall and the first portion in the first direction, the first direction being parallel to the direction from the cover portion toward the substrate; separating the extension portion from the main body portion; sealing a signal processing device into the cavity, and electrically connecting the flexible electrode to the signal processing device through the feedthrough electrode.

[0006] Optionally, the process of setting the feedthrough electrode in the body includes: providing the substrate having opposing first and second sides; forming the feedthrough electrode communicating with the first and second sides; sealing the signal processing device into the cavity includes: mounting the signal processing device to the first side and electrically connecting the signal processing device to the feedthrough electrode; providing a sidewall and a cover, the cover and the substrate being respectively connected to opposing sides of the sidewall to form the cavity.

[0007] Optionally, forming the feedthrough electrode connecting the first side and the second side includes: forming a feedthrough hole on the substrate, the feedthrough hole penetrating the first side and the second side; and filling the feedthrough hole with a conductive material to form the feedthrough electrode.

[0008] Optionally, mounting the signal processing device to the first side and electrically connecting the signal processing device to the feedthrough electrode includes: forming a metal interconnect layer on the first side, the metal interconnect layer being electrically connected to the feedthrough electrode; and electrically connecting the signal processing device to the metal interconnect layer.

[0009] Optionally, the first portion of forming the flexible electrode in the main body and the second portion of forming the flexible electrode in the extension include: forming a first insulating layer on the outside of the main body; opening a first through hole in the portion of the first insulating layer located in the main body, the first through hole corresponding to the feed electrode; filling the first through hole with a conductive material; forming a conductive layer on the first insulating layer, the conductive layer communicating with the first through hole; and forming a second insulating layer on the conductive layer to obtain the first portion and the second portion.

[0010] Optionally, the first portion includes an electrode layer; and / or, the second portion has a comb-like structure to form at least one electrode wire, wherein each electrode wire includes the electrode contact, and the electrode contact formation process includes: opening a second through hole in the portion of the first insulating layer and / or the second insulating layer located in the extension, the second through hole communicating with the conductive layer; and filling the second through hole with a conductive material to form the electrode contact.

[0011] Optionally, forming a sacrificial layer at least in the extension includes forming the sacrificial layer in the interference region of the main body and in the extension.

[0012] Optionally, the action of connecting the sidewall and the cover to the substrate is performed after folding the second part toward the first part to at least expose the interference area of ​​the main body, wherein the action of connecting the sidewall and the cover to the substrate includes connecting the sidewall and the cover to the substrate sequentially, or connecting the sidewall and the cover together to the substrate after pre-assembly.

[0013] Optionally, the method further includes: providing a limiting part in the cavity to restrict the movement of the signal processing device in the cavity.

[0014] Optionally, the signal processing device includes a multi-layer structure, with each layer electrically connected to the others via electrical connectors.

[0015] Compared with the prior art, the technical solution of the embodiments of the present invention has the following beneficial effects:

[0016] This invention provides a method for forming an implantable device, comprising: providing a body made of glass and having a feedthrough electrode, the body including a main body portion and an extension portion, the main body portion being adapted to provide a sealed cavity, the main body portion including a cover portion, a substrate disposed opposite to the cover portion, and a sidewall located between the cover portion and the substrate, the cover portion, the substrate, and the sidewall together forming the cavity, the extension portion extending outward from the main body portion; forming a sacrificial layer at least in the extension portion; forming a first portion of a flexible electrode in the main body portion, and forming a second portion of the flexible electrode in the extension portion, wherein a non-zero gap exists between the second portion and the extension portion; removing the sacrificial layer; folding the second portion toward the first portion to at least expose an interference region of the main body portion, wherein the projection of the interference region in a first direction at least covers the overlapping area of ​​the projection of the sidewall and the first portion in the first direction, the first direction being parallel to the direction from the cover portion toward the substrate; separating the extension portion from the main body portion; sealing a signal processing device into the cavity, and electrically connecting the flexible electrode to the signal processing device through the feedthrough electrode.

[0017] In the formation method provided in this embodiment, the signal processing device is sealed within a cavity formed of a single glass material. A flexible electrode is formed on the outside of the body, and a feedthrough electrode is provided on the body forming the cavity to ensure electrical connection between the signal processing device inside and outside the cavity and the flexible electrode. Therefore, the implantable device formed based on this embodiment can achieve signal interaction between the internal device and the external flexible electrode while ensuring the airtightness of the internal device and its long-term stability in the implantation environment. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of an implantable device according to an embodiment of the present invention;

[0019] Figure 2 yes Figure 1 A magnified view of a portion of region A in the middle;

[0020] Figure 3 yes Figure 1A cross-sectional view of the implantable device shown;

[0021] Figure 4 yes Figure 1 A top view of the implanted device in its intermediate state;

[0022] Figure 5 yes Figure 4 A cross-sectional view of the structure shown;

[0023] Figure 6 This is a flowchart of a method for forming an implantable device according to an embodiment of the present invention;

[0024] Figures 7 to 9 This is a schematic diagram of the formation process of an implantable device in a typical application scenario of an embodiment of the present invention;

[0025] Figure 10 This is a cross-sectional view of an intermediate state of an implantable device in a variation of an embodiment of the present invention. Detailed Implementation

[0026] As mentioned in the background section, existing implantable devices generally only focus on how to achieve signal interaction, and their performance in terms of device airtightness and long-term stability in the implantation environment is unsatisfactory.

[0027] For example, one existing implantable device uses a sandwich structure, where a flexible electrode is sandwiched between a signal acquisition chip (e.g., an analog-to-digital converter, or ADC) and a printed circuit board (PCB) to enable signal interaction. However, the overall device formed by this structure lacks sealing characteristics, especially since gaps may exist between the ADC and the flexible electrode, and between the flexible electrode and the PCB, making it impossible to guarantee the overall sealing of the implantable device.

[0028] Another type of implantable device uses Al2O3 ceramic as a substrate and is sealed via brazing and laser welding. The fabrication process for this device is complex, requiring approximately two separate steps: 1. Fabricating a ceramic substrate with a brazed metal ring; 2. Welding the internal components to the ceramic substrate with a solder coating. While the resulting device achieves a seal, a significant portion of the sealing structure is in contact with the external environment, failing to meet the long-term biocompatibility requirements for implantable devices in international and national standards. Furthermore, the brazing process requires high temperatures, necessitating that the internal components be installed onto the ceramic substrate after the metal ring. However, after brazing the metal ring to the ceramic substrate, the height of the metal ring limits the internal components' mounting to the ceramic substrate, preventing flip-chip installation. Instead, a second solderable coating must be melted and welded using reflow soldering, significantly increasing the complexity of the fabrication process.

[0029] To address the aforementioned technical problems, embodiments of the present invention provide a method for forming an implantable device, comprising: providing a body, the body being made of glass and having a feedthrough electrode, the body including a main body portion and an extension portion, the main body portion being adapted to provide a sealed cavity, the main body portion including a cover portion, a substrate disposed opposite to the cover portion, and a sidewall located between the cover portion and the substrate, the cover portion, the substrate, and the sidewall together forming the cavity, the extension portion extending outward from the main body portion; forming a sacrificial layer at least in the extension portion; forming a first portion of a flexible electrode in the main body portion, and forming a second portion of the flexible electrode in the extension portion, wherein a non-zero gap exists between the second portion and the extension portion; removing the sacrificial layer; folding the second portion toward the first portion to at least expose an interference region of the main body portion, wherein the projection of the interference region in a first direction at least covers the overlapping area of ​​the projection of the sidewall and the first portion in the first direction, the first direction being parallel to the direction from the cover portion toward the substrate; separating the extension portion from the main body portion; sealing a signal processing device into the cavity, and electrically connecting the flexible electrode to the signal processing device through the feedthrough electrode.

[0030] In the formation method provided in this embodiment, the signal processing device is sealed within a cavity formed of a single glass material. A flexible electrode is formed on the outside of the body, and a feedthrough electrode is provided on the body forming the cavity to ensure electrical connection between the signal processing device inside and outside the cavity and the flexible electrode. Therefore, the implantable device formed based on this embodiment can achieve signal interaction between the internal device and the external flexible electrode while ensuring the airtightness of the internal device and its long-term stability in the implantation environment.

[0031] To make the above-mentioned objectives, features and beneficial effects of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0032] Figure 1 This is a schematic diagram of an implantable device 100 according to an embodiment of the present invention. Figure 2 yes Figure 1 A magnified view of a portion of region A in the middle; Figure 3 yes Figure 1 The image shows a cross-sectional view of the implantable device 100. To illustrate the device structure more clearly, Figure 2 and Figure 3 Different functional structures are identified using different fill patterns.

[0033] This implementation scheme can be applied to brain-computer interface application scenarios. The implantable device 100 provided by this implementation scheme can achieve signal interaction between the brain and the device while ensuring superior device sealing and long-term stability of the implantation environment.

[0034] Specifically, in combination Figures 1 to 3 The implantable device 100 may include a body 110 having a sealed cavity 101. For example, the body 110 may be a hollow cylindrical body, the hollow portion of which is adapted to form the cavity 101. The environment inside the cavity 101 is isolated from the external environment.

[0035] Furthermore, the body 110 is made of glass. In some embodiments, the body 110 is composed of a single material component, which is a glass material component.

[0036] In some embodiments, the body 110 may include a cover portion 111 and a substrate 112 disposed opposite to each other, and a sidewall 113 located between the cover portion 111 and the substrate 112. For example, along the direction from the cover portion 111 to the substrate 112 (denoted as the x direction in the figure), the cover portion 111 and the substrate 112 are located on both sides of the sidewall 113 and are respectively connected to the sidewall 113.

[0037] Furthermore, the cover 111, the substrate 112, and the sidewall 113 together form the cavity 101. For example, the cover 111 and the substrate 112 can be connected to both sides of the sidewall 113 along the x-direction by laser welding.

[0038] For any of the connection areas between the cover 111 and the sidewall 113, and between the substrate 112 and the sidewall 113, the connection area includes the end of the sidewall 113 along the x-direction and the contact area between the cover 111 or the substrate 112 and the end. The connection area has no air gap, thus achieving good airtightness.

[0039] Further reference Figures 1 to 3The implantable device 100 may include a signal processing device 120 housed within the cavity 101. The signal processing device 120 may be, for example, an electronic device including an ADC and / or other signal output devices.

[0040] In some embodiments, the signal processing device 120 may be mounted into the cavity 101 using a flip-chip method. For example, the substrate 112 may have a first side 112a and a second side 112b opposite to each other, wherein the first side 112a faces the cover portion 111, and the signal processing device 120 may be mounted onto the first side 112a using a flip-chip process.

[0041] In some embodiments, the signal processing device 120 may include one or more components 121, which may be electrically connected to each other via electrical connectors 122 or metal interconnect layers 130.

[0042] Furthermore, component 121 can be selected from chips, PCBs, and flexible PCBs.

[0043] Furthermore, the electrical connector 122 can be, for example, a connecting cable.

[0044] For example, on a plane perpendicular to the x-direction, one or more components 121 may be located on the same layer and distributed at different positions on the substrate 112.

[0045] For example, the signal processing device 120 may include a multi-layer structure, with each layer electrically connected to the other via an electrical connector 122.

[0046] by Figure 3 Taking the illustrated structure as an example, the signal processing device 120 has a two-layer structure and specifically includes a first PCB 123, a second PCB 124, and a first chip 125. The first PCB 123 and the first chip 125 are located on the same layer and are connected to the first side 112a through a metal interconnect layer 130. Furthermore, the second PCB 124 is located on the side of the first PCB 123 and the first chip 125 that is away from the first side 112a and is electrically connected to the first PCB 123 through an electrical connector 122.

[0047] Furthermore, the metal interconnect layer 130 (also referred to as the connected metal layer) may include a solder layer, and may also include conductive structures between different solder potentials in the solder layer, which can be used to connect signal or power paths between the various components 121. For example, the metal interconnect layer 130 may be formed on the first side 112a, and then the signal processing device 120 may be soldered to the metal interconnect layer 130. The metal interconnect layer 130 located between the signal processing device 120 and the first side 112a provides an electrical connection between the signal processing device 120 and the outside of the body 110.

[0048] In a specific implementation, continue to refer to Figure 3 The implantable device 100 may also include a limiting part 131 disposed within the cavity 101, the limiting part 131 being used to restrict the movement of the signal processing device 120 within the cavity 101.

[0049] Specifically, depending on the specific structure of the signal processing device 120 inside the cavity 101, one or more types of limiting parts 131 can be used to fix the signal processing device 120, thereby reducing or even avoiding the shaking amplitude of the signal processing device 120 inside the cavity 101.

[0050] by Figure 3 Taking the signal processing device 120 with a dual-layer structure as an example, at least one support connection 132 can be provided between the first chip 125 and the second PCB 124 to limit the relative position between them. Furthermore, a shim 133 can be provided between the second PCB 124 and the cover 111 to provide a limiting and fixing function. Thus, depending on the actual internal structure of the cavity 101, the support connection 132 or the shim 133 can be appropriately used to directly fix and install different circuit elements or chips.

[0051] For example, when a softer connecting cable is used for electrical connection between the upper and lower structures, the swaying of the component 121 located in the middle or lower layer (i.e., the layer away from the first side 112a) in the cavity 101 can be reduced or even avoided by raising 133.

[0052] Furthermore, a limiting portion 131 may be provided during the installation of the signal processing device 120 into the cavity 101. For example, a limiting portion 131 may be provided between two adjacent layers.

[0053] Furthermore, a limiting part 131 can be provided after the signal processing device 120 is installed and before the closed cavity 101. For example, the limiting part 131 can be provided between the signal processing device 120, which is furthest from the first side 112a, and the cover 111.

[0054] In some embodiments, the limiting portion 131 may be disposed between the sidewall 113 and the component 121 to limit the movement of the signal processing device 120 in a plane perpendicular to the x-direction.

[0055] In some embodiments, the limiting portion 131 may be integrally formed on the cover portion 111, the substrate 112 and / or the sidewall 113. For example, the limiting portion 131 may include a groove, a boss or the like machined on the cover portion 111.

[0056] Further reference Figures 1 to 3The implantable device 100 may also include a flexible electrode 140 located on the outside of the body 110, that is, on the side of the body 110 away from the cavity 101. For example, the flexible electrode 140 may be disposed on the second side 112b of the substrate 112. In this specific embodiment, the flexibility of the flexible electrode 140 can be specifically reflected in the fact that the electrode wire 142 is a flexible structure that can be bent / folded as needed.

[0057] Furthermore, the flexible electrode 140 and the signal processing device 120 can be electrically connected via a feedthrough electrode 114 disposed on the body 110. For example, refer to... Figure 2 The feedthrough electrode 114 can connect the first side 112a and the second side 112b. The signal processing device 120 located on the first side 112a is electrically connected to the feedthrough electrode 114, and the flexible electrode 140 located on the second side 112b is also electrically connected to the feedthrough electrode 114.

[0058] Furthermore, the metal interconnect layer 130 is electrically connected to both the signal processing device 120 and the feedthrough electrode 114. In other words, the signal processing device 120 can be indirectly electrically connected to the feedthrough electrode 114 through the metal interconnect layer 130, thereby enabling signal interaction with the flexible electrode 140.

[0059] In some embodiments, the substrate 112 may have a feedthrough hole 115 extending through the first side 112a and the second side 112b, and the feedthrough hole 115 is filled with a conductive material to form a feedthrough electrode 114.

[0060] For example, a micro-hole penetrating the entire substrate 112 can be formed on one side of the substrate 112 (such as the second side 112b) by laser processing or etching to obtain the feedthrough hole 115. Furthermore, a glass feedthrough metal and glass can be hermetically sealed and welded together in the feedthrough hole 115 to obtain the feedthrough electrode 114.

[0061] In some embodiments, the diameter of the feedhole 115 can be between 5 micrometers and 500 micrometers.

[0062] In some embodiments, the conductive material may be, for example, a metallic material, such as the aforementioned glass-fed metal. In other embodiments, the conductive material may also be a metallic alloy or a non-metallic material with good conductivity, such as graphite.

[0063] In some embodiments, the number of feedthrough electrodes 114 can be multiple, and the multiple feedthrough electrodes 114 can be arranged in an array on the substrate 112. When the signal processing device 120 is mounted to the first side 112a, it can be connected via the components 121 (such as metal solder joints 126 and feedthrough holes 115) at the corresponding positions of the components 121. Figure 3The pads 127 of the first chip 125 shown are flip-chip bonded, so that each feed electrode 114 is connected to each signal point pad 127 on the first chip 125 through an independent channel formed by the corresponding glass feed metal.

[0064] In some embodiments, after the feedthrough hole 115 is formed and before the conductive material is filled, a metal layer can be formed on the inner wall of the feedthrough hole 115. This can better prevent the formation of air bubbles / gap in the feedthrough electrode 114, resulting in better electrical connection and airtightness of the feedthrough electrode 114.

[0065] In some embodiments, the flexible electrode 140 can be formed by photolithography on the second side 112b.

[0066] In some embodiments, the thickness of the substrate 112 along the x-direction can be in the range of 0.4-1 mm to reliably perform feedthrough and / or photolithography processes. Furthermore, the specific thickness of the substrate 112 can be related to the glass material used for the substrate 112; a substrate 112 made of high-hardness glass can have a smaller thickness, such as 0.2 mm.

[0067] Therefore, in this embodiment, a flexible electrode 140, fabricated by photolithography, is directly fabricated on the second side 112b of a glass wafer (such as substrate 112). An electrical connection is established between the electrode 140 and a signal processing device 120 soldered to the other side (such as the first side 112a) of the glass wafer via a glass feed metal (such as feed electrode 114). Simultaneously, the signal processing device 120 is sealed within the cavity 101 by sealing a glass wall (such as sidewall 113) and a glass cover (such as cover 111). This achieves excellent multi-channel electrode conductivity and hermetic sealing, as well as long-term stability in an implantation environment.

[0068] In one specific implementation, a metal interconnect layer 130 may also be provided between the flexible electrode 140 and the second side 112b to form a signal and power path between the flexible electrode 140 and the signal processing device 120.

[0069] In one specific implementation, multiple array units can be designed in a corresponding array configuration for the flexible electrode 140, the feedthrough electrode 114, and the metal interconnect layer 130, wherein each array unit may include Figures 1 to 3 The structure is shown. Multiple array units can be distributed at different positions on the substrate 112.

[0070] In a specific implementation, continue to refer to Figure 1 and Figure 3The flexible electrode 140 may include an electrode layer 141 formed and attached to the second side 112b, and an electrode wire 142 that can be peeled off from the second side 112b.

[0071] Specifically, electrode layer 141 and electrode wire 142 are electrically connected, and electrode layer 141 and feedthrough electrode 114 are electrically connected. Furthermore, the number of electrode wires 142 can be one or more, and each electrode wire 142 can have one or more electrode contacts 143. The electrode contacts 143 can serve as channels for electrode sites, allowing cells of a biological organism (such as the brain) implanted in the implantable device 100 to interact with the signal processing device 120 via the electrode contacts 143, feedthrough electrode 114, and metal interconnect layer 130.

[0072] For example, an electrode contact 143 can be provided at the end of each electrode wire 142. Figure 3 The electrode contacts 143 of the multiple electrode wires 142 are shown exemplarily from a side sectional view.

[0073] Furthermore, the flexible electrode 140 may include a conductive layer 144 for realizing electrical connections between the electrode layer 141 and the electrode wire 142, and between the electrode wire 142 and the electrode contact 143.

[0074] Furthermore, the flexible electrode 140 may also include an insulating layer 147, located at least along the x-direction on both sides of the conductive layer 144, to provide insulation protection. For example, see reference... Figure 3 The insulating layer 147 may include a first insulating layer 145 formed between the conductive layer 144 and the second side 112b, and may also include a second insulating layer 146 formed on the side of the conductive layer 144 facing away from the substrate 112. Furthermore, adjacent electrode wires 142 may be spaced apart by the insulating layer 147 to achieve electrical isolation. That is, except for the surface in contact with the first side 112a, the other surfaces of the conductive layer 144 are substantially enclosed by the insulating layer 147 to isolate them from the outside environment.

[0075] In some embodiments, the projection of the electrode layer 141 along the x-direction substantially falls within the boundary of the substrate 112, and at least a portion of the electrode wire 142 extends beyond the substrate 112. For example, at least the portion of the electrode wire 142 where the electrode contacts 143 are formed has its projection along the x-direction outside the substrate 112.

[0076] In some embodiments, the flexible electrode 140 may be tadpole-shaped, with the head of the tadpole being a single electrode layer 141 and the tail being a comb-shaped electrode wire 142 extending outward from the edge of the substrate 112. Figure 4 As shown. Among them, Figure 4 yes Figure 1The diagram shows a top view of an intermediate state of the implantable device 100, which may be, for example, a temporary state of the implantable device 100 during the formation (manufacturing) process.

[0077] Specifically, the coverage area of ​​the conductive layer 144 on the substrate 112 can be determined according to the setting position of the feed electrode 114 on the substrate 112, so as to ensure that all feed electrodes 114 can be reliably electrically connected to the conductive layer 144.

[0078] Furthermore, the coverage area of ​​the insulating layer 147 on the substrate 112 can far exceed the coverage area of ​​the conductive layer 144 on the substrate 112. For example, refer to Figure 4 The coverage area of ​​the conductive layer 144 can basically cover the area where the pads 127 of the signal processing device 120 and the metal interconnect layer 130 are located, while the insulating layer 147 can cover the entire substrate 112 to better provide protection.

[0079] Furthermore, for the portion of electrode wire 142, the conductive layers 144 of adjacent electrode wires 142 can be separated by an insulating layer 147 to provide insulation protection for each electrode wire 142.

[0080] In some embodiments, the coverage area of ​​the insulating layer 147 on the substrate 112 can be substantially equal to the coverage area of ​​the conductive layer 144 on the substrate 112, such as... Figures 7 to 9 As shown. In this example, the flexible electrode 140 can be elongated in shape, and the elongated electrode layer 141 extends from the position on the substrate 112 where the feed electrode 114 is provided towards the edge of the substrate 112. Typically, elongated electrode wires 142 continue to extend outward from the end of the electrode layer 141 towards the body 110. Figures 7 to 9 This is a schematic diagram illustrating the formation process of an implantable device in a typical application scenario according to an embodiment of the present invention.

[0081] In a specific implementation, refer to Figure 4 and Figure 5 The body 110 may include: a main body portion 116 having a cavity 101; and an extension portion 117 extending outward from the main body portion 116 and detachable from the main body portion 116. Figure 5 yes Figure 4 A cross-sectional view of the structure shown.

[0082] Specifically, the main body 116 may include the aforementioned cover 111, substrate 112 and sidewall 113, which are connected to form a cavity 101. Figure 4 and Figure 5 The implantable device 100 in the intermediate state shown is compared to Figures 1 to 3The main difference between the implantable device 100 in its final state (e.g., finished product state) is that the body 110 includes a removable extension 117. The extension 117 is adapted to provide a substrate for the portion of the flexible electrode 140 located outside the body 116 during the formation of the implantable device 100, so that a portion of the flexible electrode 140 (e.g., electrode wire 142) can be processed thereon by a photolithography process.

[0083] In some embodiments, the substrate 112 and the extension 117 of the main body 116 can initially be a single piece, i.e., both are made from the same glass wafer. During the formation of the implantable device 100, after the flexible electrode 140 is formed on the substrate 112 and the extension 117 by photolithography, the extension 117 is separated from the substrate 112 and from... Figure 4 and Figure 5 The intermediate state shown is obtained Figures 1 to 3 The implantable device 100 in its final state is shown.

[0084] Furthermore, the flexible electrode 140 may include: a first portion 148 formed on the main body portion 116; and a second portion 149 formed on the extension portion 117. The first portion 148 and the second portion 149 may be prepared by the same or multiple processes, and there may be no physical boundary between them, but they are divided by their positions on the glass wafer.

[0085] Furthermore, the first part 148 may include an electrode layer 141.

[0086] Furthermore, the second part 149 may have a comb-like structure to form at least one electrode wire 142.

[0087] In some embodiments, the connection between the electrode layer 141 and the electrode wire 142 may be located at the junction of the first portion 148 and the second portion 149. That is, the electrode layer 141 is entirely formed in the first portion 148, and the electrode wire 142 is entirely formed in the second portion 149.

[0088] In some embodiments, the connection between the electrode layer 141 and the electrode wire 142 may be offset from the boundary between the first portion 148 and the second portion 149. For example, the connection between the electrode layer 141 and the electrode wire 142 may be located outside the substrate 112, i.e., located in the second portion 149. Alternatively, the connection between the electrode layer 141 and the electrode wire 142 may be located inside the substrate 112, i.e., a portion of the electrode wire 142 is located on the substrate 112, such as... Figure 4 As shown.

[0089] Further reference Figure 5The second part 149 and the extension 117 may have a non-zero gap. Thus, after the extension 117 is separated from the substrate 112, the second part 149 can be smoothly separated from the extension 117, allowing the electrode wire 142 to be released from the glass wafer.

[0090] In a specific implementation, continue to refer to Figure 5 The implantable device 100 may also include a sacrificial layer 150, at least located between the second portion 149 and the extension 117.

[0091] Specifically, the sacrificial layer 150 may be a sacrificial bonding layer used to attach the electrode wire 142 to the surface of the glass wafer (such as the surface of the extension 117).

[0092] In some embodiments, the sacrificial layer 150 may be fabricated using a multi-layer composition, including but not limited to nickel (Ni), platinum (Pt), or palladium (Pd).

[0093] Furthermore, the sacrificial layer 150 may also be located between the first portion 148 and the main body portion 116. That is, the area covered by the sacrificial layer 150 on the main body 110 includes most of the area where the electrode wires 142 are located (i.e., the area where the electrode needs to be released into flexibility) and part of the substrate 112 that does not require glass separation. By making the area covered by the sacrificial layer 150 include a sufficiently large portion that does not require glass separation, damage to the flexible electrode 140 during the separation process can be avoided, and it is easier to connect the substrate 112 to the sidewall 113.

[0094] In some embodiments, the sacrificial layer 150 is located between the first portion 148 and the main body 116, at least covering the portion of the connection area of ​​the main body 116 that interferes with the first portion 148. Specifically, the connection area may include the contact area between the substrate 112 and the sidewall 113, and may also include the contact area between the sidewall 113 and the cover portion 111. The connection area may be, for example, the area that the laser will touch during laser welding.

[0095] For example, continue to refer to Figure 4 and Figure 5 The projection of the sacrificial layer 150 located between the first portion 148 and the main body 116 in the first direction at least covers the overlapping area of ​​the projections of the sidewall 113 and the first portion 148 in the first direction. The first direction is parallel to the x-direction. Therefore, when laser welding is performed to connect the cover 111, the substrate 112, and the sidewall 113 to form a sealed cavity 101, and / or when the extension 117 and the main body 116 are separated by laser cutting, the laser irradiates from above perpendicular to the substrate 112 in the x-direction. Through the sacrificial layer 150 located between the first portion 148 and the main body 116, the electrode wire 142 can be directed inward (i.e., towards the substrate 112, as shown in the image). Figure 1 (As shown) bend so that the projection in the x-direction does not fall into the area where the side wall 113 is located, to avoid the laser accidentally cutting the electrode wire 142.

[0096] Therefore, by adopting this embodiment, signal interaction between the internal devices of cavity 101 and the external flexible electrode 140 can be achieved while ensuring the airtightness of the internal devices and their long-term stability in the implantation environment. Specifically, this embodiment provides a structure with a glass seal and a flexible electrode 140. The flexible electrode 140 is fabricated on a glass substrate material and attached to the outer surface of the glass body 110. It is connected to the signal processing device 120 sealed inside the glass cavity 101 through a metal conductor (such as a feedthrough electrode 114) disposed inside the glass. Thus, the feedthrough sealing is achieved by the integrated sealing method fabricated on the glass substrate material. That is, while achieving signal connectivity, the internal environment of the glass cavity 101 is isolated from the external environment, thereby achieving long-term signal processing stability and signal transmission throughput.

[0097] Furthermore, the flexible electrode 140 may include multi-channel electrode integration. Furthermore, the entire body 110 is made of glass; the monolithic glass material structure minimizes long-term biocompatibility issues that may arise from different types of materials introduced into the implantable device 100.

[0098] Furthermore, glass possesses superior light transmittance and good chemical stability. Therefore, the implantable device 100 made of glass in this embodiment is better suited to application scenarios requiring communication, data or energy exchange between the inside and outside of a sealed cavity 101 for measurement or information processing. Furthermore, the glass body 110 enables the implantable device 100 described in this embodiment to exchange data or transmit energy via optical signals through the body 110.

[0099] Furthermore, glass has excellent thermal insulation properties, thus the implantable device 100 described in this embodiment can effectively control the heat release of the signal processing device sealed within the glass cavity 101. By allowing the heat instantaneously released within the glass cavity 101 to be released and conducted to the outside of the body 110 in a more slow manner, it is beneficial to protect the implantation safety.

[0100] Furthermore, the glass body 110 can be obtained through low-temperature welding. Since low-temperature welding has little impact on the performance of the signal processing device 120, the signal processing device 120 can be installed into the cavity 101 first, and then the cavity 101 can be sealed by low-temperature welding. Thus, the signal processing device 120 can be installed into the cavity 101 using a flip-chip process, which helps to reduce the complexity of the manufacturing process.

[0101] Furthermore, the glass body 110 can be connected using laser welding, such as by connecting the various areas of the body 110 together to form a sealed cavity 101. Since laser welding can be completed without introducing other types of materials (such as flux), it helps to reduce long-term biocompatibility issues that may arise from introducing different types of materials into the implantable device 100.

[0102] Figure 6 This is a flowchart of a method for forming an implantable device according to an embodiment of the present invention. The forming method can be used to form the aforementioned... Figures 1 to 5 The implantable device 100 described in the illustrated embodiment.

[0103] Specifically, refer to Figure 6 The method for forming the implantable device described in this embodiment may include the following steps:

[0104] Step S601, provide a body, the body is made of glass and provided with a feed electrode, the body includes a main body and an extension, the main body is adapted to provide a sealed cavity, the main body includes a cover, a substrate disposed opposite to the cover and a sidewall located between the cover and the substrate, the cover, the substrate and the sidewall together form the cavity, and the extension extends outward from the main body;

[0105] Step S602, at least a sacrificial layer is formed in the extension;

[0106] Step S603: A first portion of the flexible electrode is formed in the main body, and a second portion of the flexible electrode is formed in the extension, wherein there is a non-zero gap between the second portion and the extension;

[0107] Step S604: Remove the sacrificial layer;

[0108] Step S605: Fold the second part toward the first part to at least expose the interference area of ​​the main body, wherein the projection of the interference area in the first direction at least covers the overlapping area of ​​the sidewall and the projection of the first part in the first direction, the first direction being parallel to the direction of the cover pointing toward the substrate;

[0109] Step S606: Separate the extension from the main body;

[0110] Step S607: Seal the signal processing device into the cavity and electrically connect the flexible electrode to the signal processing device through the feedthrough electrode.

[0111] It is understood that steps S601 to S607 can be used to form the above. Figures 1 to 5The implantable device 100 is shown in the embodiment. Therefore, the explanation of the terms used in this embodiment can be found by referring to... Figures 1 to 5 The relevant descriptions of the embodiments shown will not be repeated here.

[0112] In a specific implementation, combined with Figures 1 to 5 The process of setting the feed electrode 114 on the body 110 may include the steps of: providing a substrate 112 having opposing first side 112a and second side 112b; and forming the feed electrode 114 communicating with the first side 112a and the second side 112b.

[0113] Specifically, the fabrication process of the feedthrough electrode 114 may include the following steps: forming a feedthrough hole 115 on the substrate 112, the feedthrough hole 115 extending along the x-direction and penetrating the first side 112a and the second side 112b; filling the feedthrough hole 115 with a conductive material to form the feedthrough electrode 114.

[0114] In one specific implementation, step S607 may include the steps of: mounting the signal processing device 120 to the first side 112a and electrically connecting the signal processing device 120 to the feedthrough electrode 114; providing a sidewall 113 and a cover 111, wherein the cover 111 and the substrate 112 are respectively connected to opposite sides of the sidewall 113 to form the cavity 101.

[0115] In some embodiments, the soldering process of the signal processing device 120 may include: forming a metal interconnect layer 130 on the first side 112a, the metal interconnect layer 130 being electrically connected to the feedthrough electrode 114; and electrically connecting the signal processing device 120 to the metal interconnect layer 130.

[0116] In one specific implementation, step S603 may specifically include the following process: s1, forming a first insulating layer 145 on the outer side of the body 110. For example, the first insulating layer 145 is formed on the second side 112b of the substrate 112 and on the surface of the extension 117.

[0117] s2, a first through hole is formed in the portion of the first insulating layer 145 located in the main body 116, and the first through hole corresponds to the feed electrode 114. For example, each feed electrode 114 is provided with a corresponding first through hole so that the feed electrode 114 is exposed outside the first insulating layer 145.

[0118] s3, fill the first through hole with conductive material. For each first through hole, the composition of the conductive material filling the first through hole may be the same as or different from the composition of the conductive material used in the corresponding feed electrode 114. This specific embodiment does not limit this, as long as a reliable electrical connection is ensured.

[0119] s4, a conductive layer 144 is formed on the first insulating layer 145, the conductive layer 144 connecting to the first through hole. At this time, the conductive layer 144 achieves a reliable electrical connection with the feed electrode 114 through the first through hole and the conductive material filled therein.

[0120] s5, a second insulating layer 146 is formed on the conductive layer 144 to obtain the first portion 148 and the second portion 149.

[0121] Furthermore, the process of forming the electrode contact 143 on each electrode wire may include the following steps: opening a second through hole in the portion of the first insulating layer 145 and / or the second insulating layer 146 located in the extension 117, the second through hole communicating with the conductive layer 144; filling the second through hole with conductive material to form the electrode contact 143.

[0122] In some embodiments, after filling the second through-hole with conductive material, a plating layer can also be formed at the end of the second through-hole to reduce the impedance of the electrode contact 143 when in contact with the cell and prolong the long-term stability of the electrode contact 143. The plating material may include iridium oxide or polyethylene dioxythiophene (PEDOT).

[0123] In one specific implementation, the stacking process of the flexible electrode 140 (including electrode layer 141 and flexible electrode wire 142 formed by release) can be as follows: an internal metal conduction to form a feed electrode 114 is processed on a glass wafer substrate (including substrate 112 and extension 117); then, on the second side 112b, a releasable sacrificial layer 150 is first formed using a micro-electro-mechanical system (MEMS) process, and then an insulating layer 147 (such as a first insulating layer 145) is covered on it. Then, an opening (such as a first through hole) corresponding to the electrode contact 143 is formed on the insulating layer 147, and the metal of the conductive layer 144 is connected to the corresponding metal through hole (i.e., feed electrode 114) in the glass wafer substrate; then, another insulating layer 147 (such as a second insulating layer 146) is covered, and an opening (such as a second through hole) corresponding to the electrode contact 143 is formed.

[0124] In some embodiments, the sacrificial layer 150 may be formed in the interference region of the main body 116 and the extension 117. The interference region at least covers the portion of the connection region of the main body 116 that interferes with the first portion 148.

[0125] In one specific implementation, in step S605, the second portion 149 may be folded toward the first portion 148 to at least expose the interference region of the main body 116, wherein the projection of the interference region in the first direction (parallel to the x-direction) at least covers the overlapping area of ​​the sidewall 113 and the projection of the first portion 148 in the first direction.

[0126] In one specific implementation, in step S604, a specific solution can be used to remove the sacrificial layer 150, thereby peeling the second portion 149 of the flexible electrode 140 from the glass wafer substrate (including the area on the extension 117 and the main body 116 covered with the sacrificial layer 150). Since the connection between the main body 116 and the extension 117 is also pre-covered with the sacrificial layer 150, the second portion 149 peeled from the surface of the glass wafer substrate no longer covers the glass section to be separated (i.e., the connection between the extension 117 and the main body 116).

[0127] In one specific implementation, in step S606, the extension portion 117 and the main body portion 116 can be separated by mechanically bending the glass or by laser cutting. This allows the glass wafer substrate extension region originally under the flexible electrode 140 to be separated from the glass wafer substrate that forms the main body portion 116 without damaging the electrode wire 142.

[0128] In some embodiments, the action of connecting the sidewall 113 and the cover 111 to the substrate 112 can be performed after the second portion 149 is folded toward the first portion 148 to at least expose the interference region of the main body 116. This avoids accidental laser cutting of the electrode wire 142 during the welding process to form the sealed cavity 101.

[0129] In some embodiments, the sidewall 113 and the cover plate 111 can be pre-assembled into a pre-assembled part and then connected together to the substrate 112. In some embodiments, the sidewall 113 can be connected to the substrate 112 first, and then the cover plate 111 can be connected to the sidewall 113 to seal the cavity 101.

[0130] In a typical application scenario, the formation process of the implantable device 100 may specifically include: First, providing a glass wafer substrate. The glass wafer substrate can be a single glass wafer on which multiple substrates 112 can be arrayed, wherein each substrate 112 is connected to or integrally formed with an extension 117. Then, for the region where each substrate 112 is located on the glass wafer substrate, a feedthrough hole 115 is drilled in the substrate 112 and filled with a metal material. At this time, a feedthrough electrode 114 can be fabricated. Next, a metal interconnect layer 130 is formed on the first side 112a of the substrate 112.

[0131] Next, flexible electrodes 140 are formed on the second side 112b of the substrate 112 and on the surface of the extension 117, such as Figure 7 As shown. At this time, a sacrificial layer 150 is pre-formed between the second portion 149 and the extension 117, and between a portion of the first portion 148 and the second side 112b. The fabricated flexible electrode 140 and feedthrough electrode 114 are electrically connected. During the glass wafer processing stage, the flexible electrode 140 is in an adsorption connection state with the substrate 112 / extension 117.

[0132] Next, with the first side 112a of the substrate 112 facing upwards, the signal processing device 120 is soldered to the first side 112a using a flip-chip process. At this time, the signal processing device 120 and the electrode contact 143 are electrically connected through the metal interconnect layer 130, the feed electrode 114, and the conduction layer 144.

[0133] Next, along the boundary contour including the extension 117, the glass wafer substrate is cut into individual units, resulting in... Figure 7 The structure shown. Among them, Figure 7 Sacrificial layer 150 is not shown.

[0134] Next, the sacrificial layer 150 is removed, and the electrode wire 142 is bent so that its projection along the x-direction does not fall into the interference region. For example, the sacrificial layer 150, which is photolithographically prepared beneath the electrode wire 142, can be removed by chemical methods, thereby allowing the flexible electrode wire 142 to be released from the glass wafer substrate (such as the extension 117), as... Figure 8 As shown.

[0135] Next, while keeping the electrode wire 142 bent so that its projection in the x-direction does not fall into the interference region, the sidewall 113 and the cover 111 are laser welded to the first side 112a of the substrate 112. At this time, the signal processing chip 120 is sealed in the cavity 101.

[0136] Finally, while maintaining the state where the projection of the electrode wire 142 in the x-direction does not fall into the interference region, the extended portion (i.e., the extension 117) of the glass wafer substrate is cut off at the corresponding position where the root of the electrode wire 142 is located (i.e., the junction of the extension 117 and the main body 116), as follows. Figure 9 As shown. Thus, we can obtain the following: Figure 1 The implantable device 100 in its final state is shown.

[0137] In one variation, the sidewall 113 and the cover 111 can be first connected to the first side 112a by laser welding, and then the entire main body 116 and the extension 117 can be cut off from the glass wafer substrate to obtain the following result: Figure 5 The intermediate state shown.

[0138] In one specific implementation, after the signal processing device 120 is installed on the first side 112a and before the cavity 101 is sealed, the forming method described in this embodiment may further include the step of: providing a limiting part 131 in the cavity 101 to restrict the movement of the signal processing device 120 in the cavity 101.

[0139] As described above, the formation method provided in this embodiment seals the signal processing device 120 within a cavity 101 formed of a single glass material. A flexible electrode 140 is formed on the outside of the body 110, and a feedthrough electrode 114 is provided on the body 110 forming the cavity 101 to ensure electrical connection between the signal processing device 120 and the flexible electrode 140 inside and outside the cavity 101. Therefore, signal interaction between the internal device of the cavity 101 and the external flexible electrode 140 can be achieved while ensuring the airtightness of the device inside the cavity 101 and its long-term stability in the implantation environment.

[0140] In one variation, refer to Figure 10 The electrical connector 122 may include plug-in connectors, which are respectively disposed on the opposite sides of two adjacent layers of the signal processing device 120. The two plug-in connectors disposed opposite each other are coupled to realize the electrical connection between the two adjacent layers.

[0141] Assumption Figure 10 The signal processing device 120 shown includes a second chip 128 and a third PCB 129, on which one or more chips may be integrated. The second chip 128 is closer to the first side 112a than the third PCB 129. Accordingly, on the first side 112a of the substrate 112, the second chip 128 is directly electrically connected to the metal interconnect layer 130 via pads 127 and metal solder joints 126. Furthermore, electrical connections between the third PCB 129 and the metal interconnect layer 130 and / or the second chip 128 can be achieved through electrical connections between a plug-in connector connected to the metal interconnect layer 130 and a plug-in connector mounted at a corresponding position on the third PCB 129.

[0142] Furthermore, multiple plug-in connectors of the same height can be installed between adjacent layers to ensure the stability of the lower layer (such as...). Figure 10 The third PCB129 shown is parallel to each other and is insulated. Figure 10 The example shown uses two sets of plug-in connectors. In practical applications, the specific number and position can be adjusted as needed.

[0143] further, Figure 10 The structure shown is the same as the one described above. Figure 5The difference in the structure shown is that the limiting part 131 can be eliminated. Specifically, the rigidity of the plug-in connector is relatively high, so the limiting structures such as the shim 133 and the support connection 132 can be eliminated. The plug-in connectors can cooperate to serve as both the electrical connector 122 and the limiting part 131.

[0144] While the present invention has been disclosed above, it is not limited thereto. Any person skilled in the art can make various modifications and alterations without departing from the spirit and scope of the invention; therefore, the scope of protection of the present invention should be determined by the scope defined in the claims.

Claims

1. A method of forming an implantable device, the method comprising: The method comprises: providing a body made of glass and provided with a feedthrough electrode, the body comprising a main body portion and an extension portion, the main body portion being adapted to provide a sealed cavity, the main body portion comprising a cover portion, a base portion disposed opposite to the cover portion, and a sidewall portion disposed between the cover portion and the base portion, the cover portion, the base portion and the sidewall portion collectively defining the cavity, the extension portion extending outwardly from the main body portion; forming a sacrificial layer at least at the extension portion; forming a first portion of a flexible electrode at the main body portion and a second portion of the flexible electrode at the extension portion, wherein the second portion and the extension portion have a non-zero gap therebetween; removing the sacrificial layer; folding the second portion towards the first portion to at least expose an interference region of the main body portion, wherein a projection of the interference region in a first direction covers at least an overlapping region of projections of the sidewall portion and the first portion in the first direction, the first direction being parallel to a direction in which the cover portion points to the base portion; separating the extension portion from the main body portion; sealing a signal processing device into the cavity and electrically connecting the flexible electrode to the signal processing device via the feedthrough electrode.

2. The method of forming of claim 1, wherein, The method of providing a feedthrough electrode at the body comprises: providing the base portion having opposite first and second sides; forming the feedthrough electrode communicating the first and second sides; sealing the signal processing device into the cavity comprises: mounting the signal processing device to the first side and electrically connecting the signal processing device to the feedthrough electrode; providing a sidewall and a cover portion, the cover portion and the base portion being connected to opposite sides of the sidewall to form the cavity.

3. The method of forming of claim 2, wherein, The method of forming the feedthrough electrode communicating the first and second sides comprises: opening a feedthrough hole through the first and second sides at the base portion; filling a conductive material in the feedthrough hole to form the feedthrough electrode.

4. The method of forming of claim 2, wherein, The method of mounting the signal processing device to the first side and electrically connecting the signal processing device to the feedthrough electrode comprises: forming a metal interconnection layer at the first side, the metal interconnection layer being electrically connected to the feedthrough electrode; 5. The method of forming of claim 1, wherein, electrically connecting the signal processing device to the metal interconnection layer. The method of forming a first portion of a flexible electrode at the main body portion and a second portion of the flexible electrode at the extension portion comprises: forming a first insulating layer outside the body; opening a first via at a portion of the first insulating layer at the main body portion, the first via corresponding to the feedthrough electrode; filling a conductive material in the first via; forming a conductive layer on the first insulating layer, the conductive layer communicating the first via; 6. The method of forming of claim 5, wherein, forming a second insulating layer on the conductive layer to obtain the first and second portions. The first portion comprises an electrode layer; and / or, the second portion is in a comb structure to form at least one electrode wire, wherein each electrode wire comprises an electrode contact, the method of forming the electrode contact comprises: opening a second via at a portion of the first and / or second insulating layer at the extension portion, the second via communicating the conductive layer; Filling a conductive material in the second through hole to form the electrode contact.

7. The method of forming of claim 1, wherein, The at least forming a sacrificial layer on the extension includes: The sacrificial layer is formed on the interference region of the main body and the extension.

8. The method of forming of claim 1, wherein, The action of connecting the side wall and the cover to the substrate is performed after the second part is folded towards the first part to at least expose the interference region of the main body, and the action of connecting the side wall and the cover to the substrate includes connecting the side wall and the cover to the substrate in sequence, or connecting the side wall and the cover to the substrate together after pre-assembly.

9. The method of forming of claim 1, wherein, Further comprising: A limiting part is arranged in the cavity to limit the movement of the signal processing device in the cavity.

10. The method of forming of claim 1, wherein, The signal processing device includes a multi-layer structure, and each layer structure is electrically connected through an electrical connector.

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