CN112657053B

CN112657053B - Implanted double-sided electrode and preparation method thereof

Info

Publication number: CN112657053B
Application number: CN202010246535.2A
Authority: CN
Inventors: 王蕾; 张永成
Original assignee: Shenzhen Silicon Bionics Technology Co ltd
Current assignee: Shenzhen Silicon Bionics Technology Co ltd
Priority date: 2020-03-31
Filing date: 2020-03-31
Publication date: 2024-03-29
Anticipated expiration: 2040-03-31
Also published as: CN112657053A

Abstract

The present disclosure proposes an implantable double-sided electrode having a front side and a back side opposite the front side, comprising: a first insulating layer having a plurality of first windows; a first conductive layer disposed on the first insulating layer and including a plurality of first electrode stimulation points, a plurality of first connection lines, and a plurality of first solder joints; a second insulating layer covering the first insulating layer and the first conductive layer; the second conductive layer is arranged on the second insulating layer and comprises a plurality of second electrode stimulation points, a plurality of second connecting wires and a plurality of second welding spots; and a third insulating layer covering the second conductive layer and the second insulating layer and having a plurality of second windows, wherein the plurality of first electrode stimulation points are exposed through the plurality of first windows to form a back-side electrode array, and the plurality of second electrode stimulation points are exposed through the plurality of second windows to form a front-side electrode array. According to the present disclosure, an implantable double-sided electrode with a simple process and a method for manufacturing the same can be provided.

Description

Implanted double-sided electrode and preparation method thereof

Technical Field

The present disclosure relates to an implantable double-sided electrode and a method of making the same.

Background

Electrodes are widely used in biomedical engineering, for example, electrodes can be used to acquire bioelectric signals and to electrically stimulate nerves or myogenic tissue, etc. As an example of acquiring bioelectric signals, for example, by implanting microelectrodes, it is possible to record nerve cell electrophysiological signals and acquire multidimensional weak signals such as neurotransmitter electrochemical signals such as dopamine and the like, and the method has important significance in the study of neural networks. As an example of the electrical stimulation of nerve or myogenic tissue, the electrical stimulation of specific tissue is achieved, for example, by the action of microelectrodes implanted in the body and the target tissue, specific functions, such as artificial retina, are repaired, the image is converted into stimulating electrical signals by the external device, and the microelectrodes transmit stimulating electrical current to the optic nerve, promoting the blind person to produce a certain visual experience.

For the electrode, a double-sided electrode is often required to improve the quality of the acquired bioelectric signal and the selectivity of the electrical stimulation, however, the current preparation process of the double-sided electrode is complex, and in order to reduce the damage to biological tissues, the double-sided electrode often uses a flexible material as a substrate material, and the double-sided electrode needs to be processed on the substrate due to the use of the flexible material, so that the difficulty of the preparation process of the double-sided electrode is further increased.

Patent document (CN 101172185 a) provides a method for preparing an implantable double-sided flexible microarray electrode, wherein a silicon wafer with a sacrificial layer, on which a front electrode has been prepared, is bonded to a patterned glass substrate by a bonding method through a thermal compression bonding method, a back electrode is prepared after removing the silicon wafer with the sacrificial layer, and then the glass substrate is removed, so as to obtain the flexible electrode. However, in the manufacturing method disclosed in this patent document, bonding alignment is required, deviation is liable to occur, and both substrates need to be processed, increasing the process difficulty.

Disclosure of Invention

The present disclosure has been made in view of the above-mentioned prior art, and an object thereof is to provide an implantable double-sided electrode with a simple process and a method for manufacturing the same.

To this end, in one aspect the present disclosure provides an implantable double-sided electrode having a front side and a back side opposite the front side, comprising: a first insulating layer having a plurality of first windows penetrating the first insulating layer; a first conductive layer disposed on the first insulating layer and formed in a first predetermined pattern including a plurality of first electrode stimulation points, a plurality of first connection lines, and a plurality of first solder joints connected to the plurality of first electrode stimulation points via the plurality of first connection lines, respectively; a second insulating layer formed on the first conductive layer and covering the first insulating layer and the first conductive layer; a second conductive layer disposed on the second insulating layer and formed in a second predetermined pattern including a plurality of second electrode stimulation points, a plurality of second connection parts, and a plurality of second welding spots connected to the plurality of second electrode stimulation points via the plurality of second connection lines, respectively; and a third insulating layer formed on the second conductive layer and covering the second conductive layer and the second insulating layer, and having a plurality of second windows penetrating the third insulating layer, wherein a plurality of the first electrode stimulation points correspond to the plurality of first windows such that the plurality of first electrode stimulation points are exposed to the outside through the plurality of first windows to form a back-side electrode array, the plurality of second electrode stimulation points correspond to the plurality of second windows such that the plurality of second electrode stimulation points are exposed to the outside through the plurality of second windows to form a front-side electrode array opposite to the back-side electrode array, the plurality of first pads correspond to a plurality of first channels penetrating the second insulating layer and the third insulating layer, the plurality of second pads correspond to the plurality of second channels penetrating the third insulating layer, the plurality of first channels are respectively exposed to the outside through the plurality of first channels to form a plurality of front-side electrode pads through the plurality of second channels, and the plurality of second pads are respectively exposed to the outside through the plurality of second channels to form the front-side electrode array. In an aspect of the present disclosure, a double-layered electrode structure is employed, a first window exposes a first electrode stimulation point of a first conductive layer from a back side direction, a second window exposes a second electrode stimulation point of a second conductive layer from a front side direction, and both a first pad and a second pad are exposed in the front side direction, whereby the double-layered electrode structure can be simply fabricated.

In addition, in the double-sided electrode according to an aspect of the present disclosure, optionally, the front-side electrode array and the rear-side electrode array may be staggered with respect to each other with respect to a virtual electrode array formed by orthographic projection of the front-side electrode array. This can advantageously reduce interference between the front-side electrode array and the rear-side electrode array.

In addition, in the double-sided electrode according to an aspect of the present disclosure, optionally, the front-side electrode array and the back-side electrode array are arranged in the same arrangement, distances between adjacent second electrode stimulation points in the front-side electrode array are equal to each other, and distances between adjacent first electrode stimulation points in the back-side electrode array are equal to each other. Thus, the front-side electrode array and the back-side electrode array can be manufactured easily.

In addition, in the double-sided electrode according to an aspect of the present disclosure, optionally, the first insulating layer and the second insulating layer are fused to each other, the second insulating layer and the third insulating layer are fused to each other, and the first conductive layer and the second conductive layer are insulated from each other via the second insulating layer. Thereby, the first insulating layer, the second insulating layer, and the third insulating layer can be fused into one body, and mutual interference between the first conductive layer and the second conductive layer can be further reduced.

In addition, in the double-sided electrode according to an aspect of the present disclosure, optionally, a distance between the front-side electrode array and the second pad array is smaller than a distance between the back-side electrode array and the first pad array. Thereby, the first pad array and the second pad array can be facilitated to be arranged on the same side.

In addition, in the double-sided electrode according to an aspect of the present disclosure, optionally, the double-sided electrode includes an implant terminal, a connection portion, and a soldering terminal connected to the implant terminal via the connection portion, the front-side electrode array and the back-side electrode array are located at the implant terminal, and the second pad array and the first pad array are located at the soldering terminal. Thereby, the front-side electrode array and the back-side electrode array can be conveniently arranged at one end, and the second pad array and the first pad array are arranged at the other end.

Another aspect of the present disclosure provides a method of preparing an implantable double-sided electrode, comprising the steps of: (a) Preparing a substrate having a first dielectric film and a second dielectric film opposite to each other, forming a sacrificial layer on the first dielectric film, and forming a first insulating layer on the sacrificial layer; (b) Forming a first conductive layer in a first predetermined pattern on the first insulating layer, and then forming a second insulating layer on the first conductive layer and covering the first insulating layer and the first conductive layer, the first predetermined pattern including a plurality of first electrode stimulation points, a plurality of first connection lines, and a plurality of first solder joints connected to the plurality of first electrode stimulation points via the plurality of first connection lines, respectively; (c) Forming a second conductive layer in a second predetermined pattern on the second insulating layer, and then forming a third insulating layer on the second conductive layer and covering the second insulating layer and the second conductive layer, the second predetermined pattern including a plurality of second electrode stimulation points, a plurality of second connection lines, and a plurality of second solder joints connected to the plurality of second electrode stimulation points via the plurality of second connection lines, respectively; (d) Forming a patterned mask layer on the third insulating layer and etching according to the pattern on the mask layer, so as to form a plurality of second windows, a plurality of second channels and a plurality of first channels; and (e) patterning and etching the second dielectric film to form a plurality of first windows, so as to obtain the double-sided electrode, wherein the first windows penetrate through the first insulating layer, the first channels penetrate through the second insulating layer and the third insulating layer, the second windows and the second channels penetrate through the third insulating layer respectively, the plurality of first electrode stimulation points correspond to the plurality of first windows so that the plurality of first electrode stimulation points are exposed to the outside through the plurality of first windows to form a back-side electrode array, the plurality of second electrode stimulation points correspond to the plurality of second windows so that the plurality of second electrode stimulation points are exposed to the outside through the plurality of second windows to form a front-side electrode array opposite to the back-side electrode array, the plurality of first welding points correspond to the plurality of first channels respectively, the plurality of first welding points are exposed to the outside through the plurality of first channels to form a first welding point, the plurality of second welding points correspond to the outside through the plurality of first channels to form a plurality of second welding points, and the plurality of second welding points correspond to the second welding point arrays are exposed to the outside through the plurality of first channels to the outside, and the plurality of second welding points correspond to the front-side electrode array respectively. Thus, the double-sided electrode can be simply prepared, and the yield and repeatability of the double-sided electrode preparation process can be improved.

In addition, in the double-sided electrode according to another aspect of the present disclosure, optionally, in the step (a), patterning the sacrificial layer and etching to form a groove for marking, where a position of the groove corresponds to a position of the first window is further included. Thereby, the subsequent etching of the first window can be facilitated.

In addition, in the double-sided electrode according to another aspect of the present disclosure, optionally, in the step (b), a patterned protective layer is further formed on the first insulating layer, and the protective layer is removed after the first conductive layer is formed, thereby forming the first conductive layer in a first predetermined pattern. Thereby, the first conductive layer can be simply prepared.

In addition, in the double-sided electrode according to another aspect of the present disclosure, optionally, the first insulating layer, the second insulating layer, and the third insulating layer are each made of a flexible insulating material, the flexible insulating material is at least one of polyimide, polyethylene terephthalate, parylene, silicone, polydimethylsiloxane, polymethyl methacrylate, polyethylene glycol, or polytetrafluoroethylene resin, the first conductive layer and the second conductive layer are each made of a metal material, the metal material is at least one of silver, platinum, gold, titanium, palladium, iridium, and niobium, and the sacrificial layer is at least one of aluminum, silicon oxide, chromium, and titanium. Thus, a double-sided electrode having biocompatibility and good conductivity can be prepared.

According to the present disclosure, an implantable double-sided electrode with a simple process and a method for manufacturing the same can be provided.

Drawings

The present disclosure will now be explained in further detail by way of example only with reference to the accompanying drawings, in which:

fig. 1 is a schematic diagram illustrating a structure of an implantable double-sided electrode according to an example of the present disclosure.

Fig. 2 illustrates a top view of an implantable double-sided electrode according to an example of the present disclosure.

Fig. 3 illustrates a partial view of an implantable double-sided electrode according to an example of the present disclosure.

Fig. 4 illustrates an orthographic view of first and second electrode stimulation points of an implantable double-sided electrode in front of another example of the present disclosure.

Fig. 5 shows a flow chart of a method of making an implantable double-sided electrode according to an example of the present disclosure.

Fig. 6 shows a schematic diagram of a preparation process of a preparation method of an implantable double-sided electrode according to an example of the present disclosure.

Detailed Description

Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. In the following description, the same members are denoted by the same reference numerals, and overlapping description thereof is omitted. In addition, the drawings are schematic, and the ratio of the sizes of the components to each other, the shapes of the components, and the like may be different from actual ones.

In the present disclosure, the implanted double-sided electrode 1 may be simply referred to as "double-sided electrode 1", and the preparation method of the implanted double-sided electrode 1 may be simply referred to as "preparation method". In addition, the implantable double-sided electrode 1 according to the present disclosure can be applied to, for example, artificial retina for transmitting a stimulating current to optic nerve or the like. Furthermore, the implanted double-sided electrode 1 may have a front side 1A and a rear side 1B opposite to the front side 1A.

In the present embodiment, the double-sided electrode 1 may include an implant end 1a, a connection portion 1b, and a welding end 1c. Wherein the implant end 1a may be connected with the welding end 1c via the connection portion 1b. In some examples, the implantation end 1a may have a stimulation portion that releases an electrical stimulation signal, for example, when using the double-sided electrode 1 according to the present embodiment to stimulate nerves or tissues, the implantation end 1a may be implanted in a living body (e.g., eyeball, brain, cochlea, etc.), and the stimulation portion may release an electrical stimulation signal into which a specific signal (e.g., visual signal) is converted at a specific location (e.g., retina) to repair a specific function (e.g., vision). In some examples, the welding tip 1c may be electrically connected to an external structure that converts a particular signal to an electrical stimulation signal to receive the electrical stimulation signal. Examples of the present disclosure are not limited thereto, and in some examples, the double-sided electrode 1 may acquire bioelectric signals.

Fig. 1 is a schematic diagram showing the structure of an implantable double-sided electrode 1 according to an example of the present disclosure. Fig. 2 shows a top view of an implantable double-sided electrode 1 according to an example of the present disclosure.

In the present embodiment, as shown in fig. 1, the implantable double-sided electrode 1 may include an insulating substrate 10 and a metal electrode 20. Among them, the insulating substrate 10 may include a first insulating layer 11, a second insulating layer 12, and a third insulating layer 13, and the metal electrode 20 may include a first conductive layer 21 and a second conductive layer 22. In addition, as shown in fig. 1, the first conductive layer 21 may be disposed on the first insulating layer 11, the second insulating layer 12 may be formed on the first conductive layer 21 and cover the first insulating layer 11 and the first conductive layer 21, and the third insulating layer 13 may be formed on the second conductive layer 22 and cover the second conductive layer 22 and the second insulating layer 12.

In some examples, the first conductive layer 21 may be formed in a first predetermined pattern including a plurality of first electrode stimulation points 211, a plurality of first connection lines 212, and a plurality of first welding points 213 connected to the plurality of first electrode stimulation points 211 via the plurality of first connection lines 212, respectively (refer to fig. 2). In other examples, the second conductive layer 22 may be formed in a second predetermined pattern T including a plurality of second electrode stimulation points 221, a plurality of second connection lines 222, and a plurality of second welding spots 223 connected to the plurality of second electrode stimulation points 221 via the plurality of second connection lines 222, respectively.

In some examples, the first insulating layer 11 may have a plurality of first windows 111, and the plurality of first windows 111 may extend through the first insulating layer 11. In addition, in some examples, as shown in fig. 1, the third insulating layer 13 may have a plurality of second windows 131, and the plurality of second windows 131 may penetrate the third insulating layer 13.

In some examples, optionally, the plurality of first electrode stimulation points 211 correspond to the plurality of first windows 111 such that the plurality of first electrode stimulation points 211 are exposed to the outside via the plurality of first windows 111 to form a back-side electrode array, and the plurality of second electrode stimulation points 221 correspond to the plurality of second windows 131 such that the plurality of second electrode stimulation points 221 are exposed to the outside via the plurality of second windows 131 to form a front-side electrode array P. In addition, the front-side electrode array P may be opposite to the back-side electrode array.

In some examples, the plurality of first pads 213 may correspond to the plurality of first channels 133, wherein the first channels 133 may penetrate the second insulating layer 12 and the third insulating layer 13 (referring to fig. 1). In other examples, the plurality of second pads 223 may correspond to the plurality of second channels 132, wherein the second channels 132 may penetrate the third insulating layer 13 (refer to fig. 1).

In some examples, the plurality of first pads 213 may be exposed to the outside via the plurality of first channels 133 to form a first pad array R, and the plurality of second pads 223 may be exposed to the outside via the plurality of second channels 132 to form a second pad array Q, respectively. In addition, as shown in fig. 2, the first pad array R and the second pad array Q may be located on the same side as the front side electrode array P.

In the double-sided electrode 1 according to the present embodiment, the double-layer electrode structure is adopted, the first window 111 exposes the first electrode stimulation point 211 of the first conductive layer 21 from the back side direction, the second window 131 exposes the second electrode stimulation point 221 of the second conductive layer 22 from the front side direction, and the first pad 213 and the second pad 223 are exposed in the front side direction, whereby the double-layer electrode structure can be simply manufactured, mutual interference between the first conductive layer 21 and the second conductive layer 22 can be reduced, electrical performance can be improved, and electrical connection of the first pad 213 and electrical connection of the second pad 223 can be facilitated.

In some examples, the insulating substrate 10 may be composed of a flexible insulating material. In addition, the insulating substrate 10 may have biocompatibility. In other examples, the flexible insulating material may be at least one selected from polyimide, polyethylene terephthalate, parylene, silicone, polydimethylsiloxane, polymethyl methacrylate, polyethylene glycol, or polytetrafluoroethylene resin.

In some examples, the insulating base 10 may be composed of a first insulating layer 11, a second insulating layer 12, and a third insulating layer 13. In addition, in some examples, the first, second, and third insulating layers 11, 12, and 13 may be respectively composed of flexible insulating materials. Thereby, a biocompatible double-sided electrode can be formed. In other examples, the first, second, and third insulating layers 11, 12, and 13 may be constructed of the same or different flexible insulating materials.

In some examples, the first insulating layer 11 may have a plurality of first windows 111, and each of the first windows 111 may penetrate the first insulating layer 11. In some examples, the first window 111 may be located at the implant end 1a of the double-sided electrode 1.

In some examples, the thickness of the first insulating layer 11 may be 4 μm to 7 μm. For example, the thickness of the first insulating layer 11 may be 4.0 μm, 4.5 μm, 5.0 μm, 5.5 μm, 6.0 μm, 6.5 μm, or 7.0 μm. In addition, the thickness of the first insulating layer 11 of the present disclosure is not limited thereto.

In some examples, the aperture of the first window 111 may be 100 μm to 500 μm. For example, the aperture of the first window 111 may be 100 μm, 150 μm, 200 μm, 250 μm, 300 μm, 350 μm, 400 μm, 450 μm or 500 μm. In addition, the aperture of the first window 111 of the present disclosure is not limited thereto.

In some examples, the aperture of the first window 111 may also be selected based on the number of first windows 111. In other examples, the apertures of the respective first windows 111 may be the same or different according to actual needs.

In some examples, the shape of the first window 111 is not particularly limited. For example, the first window 111 may have a regular shape such as a cylinder cube, an elliptic cylinder, a triangular cylinder, or the like, or may have an irregular shape (including a combination of a regular shape and an irregular shape). In addition, the shape of each first window 111 may be the same or different.

In some examples, the number of the first windows 111 is not particularly limited, and for example, the number of the first windows 111 may be 2, 10, 20, 40, 64, or the like, or may be 1.

In some examples, the spacing between the respective first windows 111 may be 100 μm to 1500 μm. For example, the pitch between the respective first windows 111 may be 100 μm, 200 μm, 400 μm, 600 μm, 800 μm, 1200 μm, or 1500 μm. The selection of the pitch between the first windows 111 is related to the application and the layout of the first electrode stimulation points 211. Further, the pitch between the respective first windows 111 of the present disclosure is not limited thereto.

In some examples, as shown in fig. 1, the central axis direction of the first window 111 may be substantially perpendicular to the front surface 1A and the rear surface 1B of the double-sided electrode 1. In other examples, the central axis direction of the first window 111 may be formed with an inclined angle with the front surface 1A and the rear surface 1B of the double-sided electrode 1. In addition, in some examples, the central axis direction of each first window 111 may be the same or different.

In some examples, in the second insulating layer 12, the front surface may be covered by the third insulating layer 13 and the second conductive layer 22, and the back surface may cover the first insulating layer 11 and the first conductive layer 21. In addition, the second insulating layer 12 may have a plurality of passages forming the first channel 133, and each passage may penetrate the second insulating layer 12.

In some examples, the thickness of the second insulating layer 12 may be 4 μm to 7 μm. For example, the thickness of the second insulating layer 12 may be 4.0 μm, 4.5 μm, 5.0 μm, 5.5 μm, 6.0 μm, 6.5 μm, or 7.0 μm. In addition, the thickness of the second insulating layer 12 of the present disclosure is not limited thereto.

In some examples, the aperture of the via on the second insulating layer 12 may be 100 μm to 200 μm. For example, the aperture of the via on the second insulating layer 12 may be 100 μm, 110 μm, 120 μm, 150 μm, 170 μm or 200 μm. In addition, the aperture of the via on the second insulating layer 12 of the present disclosure is not limited thereto.

In some examples, the spacing between the individual vias on the second insulating layer 12 may be 100 μm to 500 μm. For example, the pitch between the individual vias on the second insulating layer 12 may be 100 μm, 150 μm, 200 μm, 250 μm, 300 μm, 350 μm, 400 μm, 450 μm, or 500 μm. In addition, the pitch between the individual vias on the second insulating layer 12 of the present disclosure is not limited thereto. In addition, the pitches between the respective vias on the second insulating layer 12 may be equal or unequal.

In some examples, the shape of the via on the second insulating layer 12 is not particularly limited. For example, the shape of the via on the second insulating layer 12 may be a cylinder cube, an elliptic cylinder, a triangular cylinder, or the like. In other examples, the number of vias on the second insulating layer 12 is not particularly limited. For example, the number of vias on the second insulating layer 12 may be the same as the number of first windows 111.

In some examples, the third insulating layer 13 may have a plurality of second windows 131 and a plurality of second channels 132. In other examples, each of the second windows 131 may extend through the third insulating layer 13, and each of the second channels 132 may extend through the third insulating layer 13. In addition, the second window 131 may be located at the implantation end 1a of the double-sided electrode 1, and the second channel 132 may be located at the welding end 1c of the double-sided electrode 1.

In some examples, the third insulating layer 13 may include a plurality of perforations forming the first channel 133. In other examples, the perforations of the third insulating layer 13 may cooperate with the vias of the second insulating layer 12 to form the first channels 133. In addition, the first channel 133 may be located at the welding end 1c of the double-sided electrode 1.

In some examples, the thickness of the third insulating layer 13 may be 4 μm to 7 μm. For example, the thickness of the third insulating layer 13 may be 4.0 μm, 4.5 μm, 5.0 μm, 5.5 μm, 6.0 μm, 6.5 μm, or 7.0 μm. In addition, the thickness of the third insulating layer 13 of the present disclosure is not limited thereto.

In some examples, the aperture of the second window 131 may be 100 μm to 500 μm. For example, the aperture of the second window 131 may be 100 μm, 150 μm, 200 μm, 250 μm, 300 μm, 350 μm, 400 μm, 450 μm or 500 μm. In addition, the aperture of the second window 131 of the present disclosure is not limited thereto. Further, the aperture of the second window 131 may be the same as or different from the aperture of the first window 111.

In some examples, the aperture of the second window 131 may also be selected according to the number of second windows 131. In some examples, the apertures of the respective second windows 131 may be the same. In other examples, the aperture of each second window 131 may be different according to actual needs.

In some examples, the shape of the second window 131 is not particularly limited. For example, the second window 131 may have a regular shape such as a cylinder cube, an elliptic cylinder, a triangular cylinder, or the like, or may have an irregular shape (including a combination of a regular shape and an irregular shape). In addition, the shape of each second window 131 may be the same or different.

In some examples, the number of the second windows 131 is not particularly limited, and for example, the number of the second windows 131 may be 2, 10, 20, 40, 64, or the like, or may be 1. In addition, the number of the second windows 131 may be the same as or different from the number of the first windows 111.

In some examples, the spacing between the respective second windows 131 may be 100 μm to 1500 μm. For example, the pitch between the respective second windows 131 may be 100 μm, 200 μm, 400 μm, 600 μm, 800 μm, 1200 μm, or 1500 μm. In addition, the interval between the respective second windows 131 of the present disclosure is not limited thereto. The selection of the pitch between the second windows 131 is dependent on the application and the layout of the second electrode stimulation points 221.

In some examples, as shown in fig. 1, the central axis direction of the second window 131 may be substantially perpendicular to the front surface 1A and the rear surface 1B of the double-sided electrode 1. In other examples, the central axis direction of the second window 131 may form an oblique angle with the front surface 1A and the rear surface 1B of the double-sided electrode 1. In addition, in some examples, the central axis direction of each second window 131 may be the same or different.

In some examples, the aperture of the second channel 132 may be 100 μm to 200 μm. For example, the aperture of the second channel 132 may be 100 μm, 110 μm, 120 μm, 150 μm, 170 μm, or 200 μm. In addition, the aperture of the second channel 132 of the present disclosure is not limited thereto.

In other examples, the spacing between each of the second channels 132 may be 100 μm to 500 μm. For example, the spacing between the respective second channels 132 may be 100 μm, 150 μm, 200 μm, 250 μm, 300 μm, 350 μm, 400 μm, 450 μm, or 500 μm. In addition, the pitch between the respective second channels 132 of the present disclosure is not limited thereto. Further, the spacing between the respective second channels 132 may be equal or unequal.

In some examples, the shape of the second channel 132 is not particularly limited. For example, the second window 131 may have a regular shape such as a cylinder cube, an elliptic cylinder, a triangular cylinder, or the like, or may have an irregular shape (including a combination of a regular shape and an irregular shape). In addition, the shape of each second channel 132 may be the same or different.

In some examples, the number of second channels 132 is not particularly limited. For example, the number of second channels 132 may be the same as or different from the number of second windows 131.

In some examples, as shown in fig. 1, the central axis direction of the second channel 132 may be substantially perpendicular to the front surface 1A and the back surface 1B of the double-sided electrode 1. In other examples, the central axis direction of the second channel 132 may form an oblique angle with the front surface 1A and the rear surface 1B of the double-sided electrode 1. In addition, in some examples, the central axis direction of each second channel 132 may be the same or different.

In some examples, the aperture of the perforation on the third insulating layer 13 may be 100 μm to 200 μm. For example, the aperture of the perforation hole in the third insulating layer 13 may be 100 μm, 110 μm, 120 μm, 150 μm, 170 μm or 200 μm. In addition, the aperture of the perforation hole on the third insulating layer 13 of the present disclosure is not limited thereto.

In some examples, the spacing between the individual perforations on the third insulating layer 13 may be 100 μm to 500 μm. For example, the spacing between the individual perforations on the third insulating layer 13 may be 100 μm, 150 μm, 200 μm, 250 μm, 300 μm, 350 μm, 400 μm, 450 μm or 500 μm. In addition, the pitch between the respective perforations on the third insulating layer 13 of the present disclosure is not limited thereto. In addition, the intervals between the respective perforations on the third insulating layer 13 may be equal or unequal.

In some examples, the shape of the perforation hole on the third insulating layer 13 is not particularly limited. For example, the shape of the through hole in the third insulating layer 13 may be a cylinder cube, an elliptic cylinder, a triangular cylinder, or the like. In other examples, the number of perforations on the third insulating layer 13 is not particularly limited. For example, the number of perforations on the third insulating layer 13 may be the same as the number of first windows 111, and the number of perforations on the third insulating layer 13 may be the same as the number of vias on the second insulating layer 12.

In some examples, as shown in fig. 1, the first channel 133 may be composed of the perforation of the third insulating layer 13 and the via of the second insulating layer 12 having the same shape and aperture. In other examples, the perforation of the third insulating layer 13 and the axis of the via of the second insulating layer 12 are on the same line.

In some examples, the aperture of the first channel 133 may be 100 μm to 200 μm. In addition, the aperture of the first channel 133 of the present disclosure is not limited thereto. Further, the aperture of the first channel 133 may be the same as or different from the aperture of the second channel 132.

In some examples, the spacing between the respective first channels 133 may be 100 μm to 500 μm. In addition, the pitch between the respective first channels 133 of the present disclosure is not limited thereto. Further, the pitches between the respective first passages 133 may be equal or unequal.

In some examples, the shape of the first channel 133 is not particularly limited. For example, the second window 131 may have a regular shape or an irregular shape (including a combination of a regular shape and an irregular shape). In addition, the shape of each first channel 133 may be the same or different.

In some examples, the number of first channels 133 is not particularly limited. For example, the number of first channels 133 may be the same as or different from the number of first windows 111.

In some examples, the central axis direction of the first channel 133 may be substantially perpendicular to the front and back surfaces 1A and 1B of the double-sided electrode 1. In other examples, the central axis direction of the first channel 133 may be formed with an oblique angle with the front surface 1A and the rear surface 1B of the double-sided electrode 1. In addition, in some examples, the central axis direction of each first channel 133 may be the same or different.

In some examples, the first insulating layer 11 and the second insulating layer 12 may be fused to each other, and the second insulating layer 12 and the third insulating layer 13 may be fused to each other. Thereby, the first insulating layer 11, the second insulating layer 12, and the third insulating layer 13 can be fused into one body. That is, there may be no distinct boundary between the first insulating layer 11 and the second insulating layer 12, and there may be no distinct boundary between the second insulating layer 12 and the third insulating layer 13. In other words, the insulating substrate 10 may be integrally formed. Thereby, the possibility of post-implantation delamination can be reduced.

In some examples, the metal electrode 20 may be composed of a conductive metal material. In addition, the metal electrode 20 may have biocompatibility. In other examples, the metal electrode 20 may be composed of at least one selected from silver, platinum, gold, titanium, palladium, iridium, niobium.

In some examples, the metal electrode 20 may include a first conductive layer 21 and a second conductive layer 22. In some examples, the first conductive layer 21 and the second conductive layer 22 may be respectively composed of a metal material. In some examples, the metallic material may be at least one selected from silver, platinum, gold, titanium, palladium, iridium, niobium. Thus, a double-sided electrode having good conductivity can be formed. In other examples, the first conductive layer 21 and the second conductive layer 22 may be composed of the same material.

In some examples, the first conductive layer 21 and the second conductive layer 22 may be composite metal layers, such as titanium-platinum-titanium structures, titanium-gold-titanium structures, niobium-gold-niobium structures, and the like. Thus, the conductive material can have good conductivity.

In some examples, the thickness of the first conductive layer 21 may be 400nm to 600nm. For example, the thickness of the first conductive layer 21 may be 400nm, 450nm, 500nm, 550nm, 600nm, 650nm, or 700nm.

In some examples, the thickness of the second conductive layer 22 may be 400nm to 600nm. For example, the thickness of the second conductive layer 22 may be 400nm, 450nm, 500nm, 550nm, 600nm, 650nm, or 700nm. In addition, the thickness of the first conductive layer 21 may be the same as or different from the thickness of the second conductive layer 22.

In some examples, in the composite metal layer, the upper metal layer may have a thickness of 30nm to 100nm, the middle metal layer may have a thickness of 100nm to 300nm, and the lower metal layer may have a thickness of 30nm to 100nm. For example, in a titanium-platinum-titanium structure, the thickness of the titanium metal layer may be 30nm to 100nm, the thickness of the platinum metal layer may be 100nm to 300nm, and the thickness of the titanium metal layer may be 30nm to 100nm.

In some examples, as shown in fig. 1, one end of the first conductive layer 21 at the implant end 1a may be aligned with one end of the second conductive layer 22 at the implant end 1 a. In addition, the first conductive layer 21 and the second conductive layer 22 may be misaligned at both ends.

In some examples, as shown in fig. 2, the first conductive layer 21 is formed in a first predetermined pattern on the first insulating layer 11. In other examples, as shown in fig. 2, the first conductive layer 21 may include a plurality of first electrode stimulation points 211, a plurality of first connection lines 212, and a plurality of first welding points 213.

In some examples, as shown in fig. 2, the first predetermined pattern may be composed of a plurality of first electrode stimulation points 211, a plurality of first connection lines 212, and a plurality of first welding points 213 connected to the plurality of first electrode stimulation points 211 via the plurality of first connection lines 212, respectively.

In some examples, the shape of the first electrode stimulation points 211 is not particularly limited, and for example, the first electrode stimulation points 211 may have a regular shape, such as a circle, a square, a diamond, a triangle, etc., or may have an irregular shape (including a shape formed by combining a regular shape and an irregular shape). In addition, the shape of each first electrode stimulation point 211 may be the same or different.

In some examples, the number of the first electrode stimulation points 211 is not particularly limited, and for example, the number of the first electrode stimulation points 211 may be 2, 10, 20, 40, 64, or the like, or may be 1. In addition, the number of the first electrode stimulation points 211 may be the same as or different from the number of the first windows 111.

In some examples, the arrangement shape of the first electrode stimulation points 211 is not particularly limited. In some examples, the first electrode stimulation points 211 may be arranged in a regular shape such as an octagonal array, square, circular, or the like. In other examples, the first electrode stimulation points 211 may also be arranged in irregular shapes (including shapes that combine regular and irregular shapes). In addition, the arrangement of the first windows 111 may be the same as the arrangement of the first electrode stimulation points 211.

In some examples, the outer diameter of the first electrode stimulation points 211 may be 100 μm to 500 μm. For example, the outer diameter of the first stimulation point may be 100 μm, 150 μm, 200 μm, 250 μm, 300 μm, 350 μm, 400 μm, 450 μm or 500 μm. In addition, the outer diameter of the first stimulation point may be equal or unequal to the aperture of the first window 111.

In some examples, the outer diameter of the first electrode stimulation points 211 may also be selected based on the number of first electrode stimulation points 211. In other examples, the outer diameter of each first electrode stimulation site 211 may be the same or different, depending on the actual requirements.

In some examples, the spacing between the individual first electrode stimulation points 211 may be 100 μm to 1500 μm. For example, the spacing between the respective first electrode stimulation points 211 may be 100 μm, 200 μm, 400 μm, 600 μm, 800 μm, 1200 μm, or 1500 μm. In addition, the selection of the spacing between the individual first electrode stimulation points 211 is dependent on the application and layout.

In some examples, the shape of the first welding spot 213 is not particularly limited, and for example, the first welding spot 213 may have a ring shape such as a circular ring, a square ring elliptical ring, a circular square hole, a square round hole, or the like. This can facilitate the electrical connection of the first pads 213. In addition, in some examples, the first connection line 212 may be elongated, such as a string.

In some examples, the outer diameter of the first weld 213 may be 100 μm to 200 μm. For example, the outer diameter of the first welding spot 213 may be 100 μm, 110 μm, 120 μm, 150 μm, 170 μm or 200 μm. In addition, the outer diameter of the first welding spot 213 may be equal to or different from the aperture of the first channel 133.

In some examples, the spacing between the respective first pads 213 may be 100 μm to 500 μm. For example, the pitch between the respective first pads 213 may be 100 μm, 150 μm, 200 μm, 250 μm, 300 μm, 350 μm, 400 μm, 450 μm, or 500 μm. In addition, the pitches between the respective first pads 213 may be equal or unequal.

In some examples, the number of first pads 213 is not particularly limited. For example, the number of first pads 213 may be the same as or different from the number of first stimulation points. In addition, the number of the first pads 213 may be the same as or different from the number of the first channels 133. Further, the number of first pads 213 may be the same as or different from the number of first stimulation points.

In some examples, the arrangement shape of the first welding spots 213 is not particularly limited. In some examples, the first pads 213 may be arranged in a regular shape such as an octagonal array, square, circular, etc. In other examples, the first welding spots 213 may also be arranged in an irregular shape (including a shape formed by combining a regular shape and an irregular shape). In addition, the arrangement of the first channels 133 may be the same as the arrangement of the first pads 213.

In some examples, as shown in fig. 1, the first electrode stimulation points 211 may correspond to the first window 111. In other examples, the first electrode stimulation points 211 may be exposed to the outside via the first window 111.

In some examples, the plurality of first electrode stimulation points 211 may correspond to the plurality of first windows 111, respectively. In other words, each of the first electrode stimulation points 211 may correspond to one of the first windows 111.

In some examples, the plurality of first electrode stimulation points 211 may be exposed to the outside via the plurality of first windows 111, respectively, to form a backside electrode array (refer to fig. 2). In other words, the respective first electrode stimulation sites 211 may be exposed to the outside through one first window 111 and arranged in a backside electrode array, respectively.

In some examples, the arrangement of the back-side electrode array is not particularly limited. In some examples, the backside electrode array may be arranged in a regular shape such as an octagonal array, square, circular, etc. In other examples, the back-side electrode array may be arranged in an irregular shape (including a shape formed by combining a regular shape and an irregular shape). In addition, the distances between adjacent first electrode stimulation points 211 in the back-side electrode array may be equal to each other. Thus, the back-side electrode array can be easily manufactured.

In some examples, as shown in fig. 1, the first solder joint 213 may correspond to the first channel 133. In other examples, the first welding spot 213 may be exposed to the outside via the first channel 133.

In some examples, the plurality of first pads 213 may correspond to the plurality of first channels 133, respectively. In other words, each of the first pads 213 may correspond to one of the first channels 133, respectively.

In some examples, the plurality of first pads 213 may be exposed to the outside via the plurality of first channels 133, respectively, to form a first pad array R (refer to fig. 2). In other words, each of the first pads 213 may be exposed to the outside through one of the first channels 133 and arranged in the first pad array R, respectively.

In some examples, the arrangement of the first pad array R is not particularly limited. In some examples, the first pad array R may be arranged in a regular shape such as an octagonal array, square, circular, etc. In other examples, the first pad array R may be arranged in an irregular shape (including a shape formed by combining a regular shape and an irregular shape). In addition, distances between adjacent first pads 213 in the first pad array R may be equal to each other.

In some examples, as shown in fig. 2, in the first conductive layer 21, the plurality of first electrode stimulation points 211 may be connected with the plurality of first welding points 213 via the plurality of first connection lines 212, respectively. In other words, the plurality of first electrode stimulation points 211 may be connected to the plurality of first pads 213 via the plurality of first connection lines 212 in a one-to-one correspondence. That is, each first electrode stimulation point 211 may be connected to one first welding point 213 via one first connection line 212. In addition, the first connection lines 212 may not contact each other.

In some examples, in the first conductive layer 21, two or more first electrode stimulation points 211 may be connected to one first pad 213 via at least one first connection line 212. For example, two first electrode stimulation points 211 may be connected to one first welding point 213 via one first connection line 212, two first electrode stimulation points 211 may be connected to one first welding point 213 via two first connection lines 212, and the like.

In some examples, the second conductive layer 22 is formed in a second predetermined pattern T on the second insulating layer 12. In other examples, the second conductive layer 22 may include a plurality of second electrode stimulation points 221, a plurality of second connection lines 222, and a plurality of second pads 223.

In some examples, the second predetermined pattern T may be composed of a plurality of second electrode stimulation points 221, a plurality of second connection lines 222, and a plurality of second welding points 223 connected to the plurality of second electrode stimulation points 221 via the plurality of second connection lines 222, respectively.

In some examples, the shape of the second electrode stimulation points 221 is not particularly limited, and for example, the second electrode stimulation points 221 may have a regular shape, such as a circle, a square, a diamond, a triangle, or the like, or may have an irregular shape (including a shape formed by combining a regular shape and an irregular shape). In addition, the shape of each second electrode stimulation point 221 may be the same or different.

In some examples, the number of the second electrode stimulation points 221 is not particularly limited, and for example, the number of the second electrode stimulation points 221 may be 2, 10, 20, 40, 64, or the like, or may be 1. In addition, the number of the second electrode stimulation points 221 may be the same as or different from the number of the second windows 131. In addition, the number of the second electrode stimulation points 221 may be the same as or different from the number of the first electrode stimulation points 211.

In some examples, the arrangement shape of the second electrode stimulation points 221 is not particularly limited. In some examples, the second electrode stimulation points 221 may be arranged in a regular shape such as an octagonal array, square, circular, or the like. In other examples, the second electrode stimulation points 221 may also be arranged in irregular shapes (including shapes that combine regular and irregular shapes). In addition, the arrangement of the second windows 131 may be the same as the arrangement of the second electrode stimulation points 221. In addition, the arrangement of the second electrode stimulation points 221 may be the same as the arrangement of the first electrode stimulation points 211.

In some examples, the outer diameter of the second electrode stimulation point 221 may be 100 μm to 500 μm. For example, the outer diameter of the second stimulation point may be 100 μm, 150 μm, 200 μm, 250 μm, 300 μm, 350 μm, 400 μm, 450 μm or 500 μm. In addition, the outer diameter of the second stimulation point may be equal or different from the aperture of the second window 131. Further, the outer diameter of the second stimulation point may be the same as or different from the outer diameter of the first stimulation point.

In some examples, the outer diameter of the second electrode stimulation points 221 may also be selected based on the number of second electrode stimulation points 221. In other examples, the outer diameter of each second electrode stimulation point 221 may be the same or different, depending on the actual requirements.

In some examples, the spacing between the individual second electrode stimulation points 221 may be 100 μm to 1500 μm. For example, the spacing between the respective second electrode stimulation points 221 may be 100 μm, 200 μm, 400 μm, 600 μm, 800 μm, 1200 μm, or 1500 μm. In addition, the selection of the spacing between the individual second electrode stimulation points 221 is dependent on the application and layout.

Fig. 3 shows a partial view of an implantable double-sided electrode 1 according to an example of the present disclosure. Fig. 3 (a) shows a schematic structural view of the second welding spot 223 of the implantable double-sided electrode 1 according to the example of the present disclosure, and fig. 3 (b) shows a top view of the second welding spot 223 of the implantable double-sided electrode 1 according to the example of the present disclosure.

In some examples, the shape of the second welding spot 223 is not particularly limited, and for example, the second welding spot 223 may have a ring shape such as a circular ring (refer to fig. 3), a square ring elliptical ring, a circular square hole, a square circular hole, or the like. Thereby, the second pad 223 can be electrically connected advantageously. In addition, in two examples, the second connection line 222 may be long, such as a rope.

In some examples, the outer diameter of the second weld 223 may be 100 μm to 200 μm. For example, the outer diameter of the second welding spot 223 may be 100 μm, 110 μm, 120 μm, 150 μm, 170 μm, or 200 μm. In addition, the outer diameter of the second welding spot 223 may be equal to or different from the aperture of the second channel 132. Further, the outer diameter of the second welding spot 223 may be the same as or different from the outer diameter of the first welding spot 213.

In some examples, the spacing between the respective second pads 223 may be 100 μm to 500 μm. For example, the pitch between the respective second pads 223 may be 100 μm, 150 μm, 200 μm, 250 μm, 300 μm, 350 μm, 400 μm, 450 μm, or 500 μm. In addition, the pitches between the respective second pads 223 may be equal or unequal.

In some examples, the number of second pads 223 is not particularly limited. For example, the number of second pads 223 may be the same as or different from the number of second stimulation points. In addition, the number of the second pads 223 may be the same as or different from the number of the second channels 132. Further, the number of second pads 223 may be the same as or different from the number of second stimulation points.

In some examples, the arrangement shape of the second welding spots 223 is not particularly limited. In some examples, the second pads 223 may be arranged in a regular shape such as an octagonal array, square, circular, etc. In other examples, the second spot welds 223 may also be arranged in irregular shapes (including shapes that combine regular and irregular shapes). In addition, the arrangement of the second channels 132 may be the same as the arrangement of the second pads 223.

In some examples, as shown in fig. 1, the second electrode stimulation points 221 may correspond to the second window 131. In other examples, the second electrode stimulation points 221 may be exposed to the outside via the second window 131.

In some examples, the plurality of second electrode stimulation points 221 may correspond to the plurality of second windows 131, respectively. In other words, each of the second electrode stimulation points 221 may correspond to one of the second windows 131, respectively.

In some examples, the plurality of second electrode stimulation points 221 may be exposed to the outside via the plurality of second windows 131, respectively, to form the front-side electrode array P. In other words, each of the second electrode stimulation points 221 may be exposed to the outside through one of the second windows 131 and arranged in the front-side electrode array P, respectively.

In some examples, the arrangement of the front-side electrode array P is not particularly limited. In some examples, the front-side electrode array P may be arranged in a regular shape such as an octagonal array, square, circular, or the like. In other examples, the front-side electrode array P may be arranged in an irregular shape (including a combination of a regular shape and an irregular shape). In addition, the distances between adjacent second electrode stimulation points 221 in the front-side electrode array P may be equal to each other. Thus, the front electrode array P can be easily manufactured.

In some examples, the front-side electrode array P and the back-side electrode array may be arranged in the same arrangement. In other examples, the front-side electrode array P and the back-side electrode array may be arranged in different arrangements.

Fig. 4 shows an orthographic view of a first electrode stimulation point 211 and a second electrode stimulation point 221 of an implantable double-sided electrode 1 in accordance with another example of the present disclosure on a front side 1A.

In some examples, as shown in fig. 4, the virtual electrode arrays formed by orthographic projections of the front side electrode array P and the rear side electrode array on the front side 1A may be staggered with each other. This can advantageously reduce interference between the front-side electrode array P and the rear-side electrode array. In other examples, the virtual electrode arrays formed by orthographic projections of the front-side electrode array P and the rear-side electrode array on the front surface 1A may overlap or intersect.

In some examples, as shown in fig. 1, the second solder joint 223 may correspond to the second channel 132. In other examples, the second welding spot 223 may be exposed to the outside via the second channel 132.

In some examples, the plurality of second pads 223 may correspond to the plurality of second channels 132, respectively. In other words, each of the second pads 223 may correspond to one of the second channels 132, respectively.

In some examples, the plurality of second pads 223 may be exposed to the outside through the plurality of second channels 132, respectively, to form a second pad array Q (refer to fig. 2). In other words, each of the second pads 223 may be exposed to the outside through one of the second channels 132 and arranged in the second pad array Q, respectively.

In some examples, the arrangement of the second pad array Q is not particularly limited. In some examples, the second pad array Q may be arranged in a regular shape such as an octagonal array, square, circular, etc. In other examples, the second pad array Q may be arranged in an irregular shape (including a shape formed by combining a regular shape and an irregular shape). In addition, the distances between adjacent second pads 223 in the second pad array Q may be equal to each other.

In some examples, a distance between the front-side electrode array P and the second pad array Q may be smaller than a distance between the back-side electrode array and the first pad array R. Thereby, the first pad array R can be facilitated to be disposed on the same side as the second pad array Q. In addition, a distance between the front-side electrode array P and the second pad array Q may be greater than or equal to a distance between the rear-side electrode array and the first pad array R.

In some examples, as shown in fig. 2, the first pad array R and the second pad array Q are disposed on the same side to facilitate electrical connection of the double-sided electrode 1 (e.g., to the feed-through ceramic).

In some examples, the front side electrode array P and the back side electrode array may be located at the implant end 1a, and the second pad array Q and the first pad array R may be located at the bonding end 1c. Thereby, the front-side electrode array P and the back-side electrode array can be conveniently arranged at one end, and the second pad array Q and the first pad array R are arranged at the other end.

In some examples, in the second conductive layer 22, the plurality of second electrode stimulation points 221 may be connected with the plurality of second pads 223 via the plurality of second connection lines 222, respectively. In other words, the plurality of second electrode stimulation points 221 may be connected to the plurality of second pads 223 in one-to-one correspondence via the plurality of second connection lines 222. That is, each of the second electrode stimulation points 221 may be connected to one of the second welding points 223 via one of the second connection lines 222. In addition, the second connection lines 222 may not contact each other.

In some examples, in the second conductive layer 22, two or more second electrode stimulation points 221 may be connected to one second solder joint 223 via at least one second connection line 222. For example, two second electrode stimulation points 221 may be connected to one second welding point 223 via one second connection line 222, two second electrode stimulation points 221 may be connected to one second welding point 223 via two second connection lines 222, and so on.

In some examples, the first connection line 212 and the second connection line 222 may be located at the connection portion 1b. Thus, the first electrode stimulation point 211 and the first pad 213, and the second electrode stimulation point 221 and the second pad 223 can be easily connected.

In some examples, the width of the connection portion 1b may be smaller than the width of the implant end 1a and the welding end 1 c. This can facilitate implantation of the double-sided electrode 1. In other examples, the length of the connection portion 1b may be greater than the lengths of the implant end 1a and the welding end 1 c. Thereby, the implantation depth of the double-sided electrode 1 can be advantageously increased.

In some examples, the surfaces of the first electrode stimulation points 211, 221 may be arranged with an analyte-responsive sensitive substance that reacts specifically with the target analyte. Thus, the concentration of the target analyte can be sensed by the reaction. In this case, chemical information during the reaction can be converted by the double-sided electrode 1 into a signal, such as an electrical signal, which can be measured, while the double-sided electrode 1 can be used for real-time continuous monitoring of parameters of the target analyte in the living body. For example, the double-sided electrode 1 may be uric acid monitoring, cholesterol monitoring, blood glucose monitoring, etc., and the sensitive substance responsive to the analyte may be different according to actual demands.

In some examples, the implant end 1a may be arranged with a biocompatible coating, whereby the implant end 1a can have a higher biocompatibility. In addition, the biocompatible coating can prevent non-target analytes in the body from contacting sensitive substances responding to the analytes of the double-sided electrode 1, and has an anti-interference effect. Examples of the present disclosure are not limited thereto, and in some examples, the biocompatible coating may cover the entire double-sided electrode 1.

In some examples, the biocompatible coating may be made of a plant material. The plant material can be at least one of sodium alginate, tragacanth, pectin, acacia, xanthan gum, guar gum, agar, etc., and derivatives of natural materials. Wherein the natural material derivative may comprise a starch derivative or a cellulose derivative.

Fig. 5 is a flowchart showing a method of manufacturing the implantable double-sided electrode 1 according to the example of the present disclosure. Fig. 6 is a schematic diagram showing a process of manufacturing the implantable double-sided electrode 1 according to the example of the present disclosure.

Hereinafter, a method of manufacturing the implantable double-sided electrode 1 according to an example of the present disclosure will be described in detail with reference to fig. 5 and 6. In addition, specific descriptions of the first conductive layer 21, the second conductive layer 22, the first insulating layer 11, the second insulating layer 12, and the third insulating layer 13 in the manufacturing method may be referred to corresponding descriptions in the above-described double-sided electrode 1. In addition, the implantable double-sided electrode 1 obtained by the manufacturing method according to the present embodiment can be specifically described with reference to the above.

In the present embodiment, as shown in fig. 5, the method of manufacturing the implantable double-sided electrode 1 may include preparing a substrate 2 having a first dielectric film 3a and a second dielectric film 3b opposite to each other, forming a sacrificial layer 4 on the first dielectric film 3a, and forming a first insulating layer 11 on the sacrificial layer 4 (step S10); forming a first conductive layer 21 in a first predetermined pattern on the first insulating layer 11, and then forming a second insulating layer 12 on the first conductive layer 21 and covering the first insulating layer 11 and the first conductive layer 21 (step S20); forming a second conductive layer 22 in a second predetermined pattern T on the second insulating layer 12, and then forming a third insulating layer 13 on the second conductive layer 22 and covering the second insulating layer 12 and the second conductive layer 22 (step S30); forming a patterned mask layer 5 on the third insulating layer 13 and etching according to the pattern on the mask layer 5, thereby forming a plurality of second windows 131, a plurality of second channels 132, and a plurality of first channels 133 (step S40); the second dielectric film 3b is subjected to patterning processing and etching, thereby forming a plurality of first windows 111 to obtain the double-sided electrode 1 (step S50).

In the method for manufacturing the implanted double-sided electrode 1 according to the present embodiment, the double-sided electrode 1 is manufactured on a single substrate and obtained by a simple and highly repeatable process such as double-sided etching, deep trench etching, etc., whereby the double-sided electrode 1 can be manufactured simply and yield and repeatability of the manufacturing process of the double-sided electrode 1 can be improved.

In some examples, in step S10, as shown in fig. 6a, the substrate 2 may have a front side and a back side opposite the front side. In addition, in some examples, the first dielectric film 3a and the second dielectric film 3b may be formed on the front surface and the back surface of the substrate 2, respectively. For example, the first dielectric film 3a may be formed on the front surface of the substrate 2, and the second dielectric film 3b may be formed on the back surface of the substrate 2. In this case, the first dielectric film 3a and the second dielectric film 3b can reduce damage caused by the subsequent etching process, and thus can be advantageous in improving process accuracy.

In some examples, in step S10, a cleaning step may be performed before forming the first dielectric film 3a and the second dielectric film 3b on the substrate 2. Thereby, the oxide layer on the surface of the substrate 2 can be removed. For example, the substrate 2 may be cleaned using an FSI cleaner to remove an oxide layer on the surface of the substrate 2.

In some examples, in step S10, the substrate 2 may be selected to be double polished, whereby the first dielectric film 3a and the second dielectric film 3b can be formed on the front and back sides of the substrate 2, respectively. In other examples, in step S10, the substrate 2 may be selected from one of glass, silicon dioxide, and silicon nitride.

In some examples, the first dielectric film 3a may be composed of at least one of a silicon oxide layer and a silicon nitride layer. In other examples, the first dielectric film 3a may be a composite dielectric film formed by stacking a silicon oxide layer and a silicon nitride layer.

In some examples, the second dielectric film 3b may be composed of at least one of a silicon oxide layer and a silicon nitride layer. In other examples, the second dielectric film 3b may be a composite dielectric film formed by stacking a silicon oxide layer and a silicon nitride layer. In addition, the first dielectric film 3a and the second dielectric film 3b may be the same or different.

In some examples, in the composite dielectric film, the silicon dioxide layer may not exceed 3 μm and the silicon nitride layer may not exceed 2 μm. For example, in a composite dielectric film, the silicon dioxide layer may be 0.5 μm, 1 μm, 1.5 μm, 2 μm, 2.5 μm or 3 μm, and the silicon nitride layer may be no more than 0.2, 0.5 μm, 1 μm, 1.5 μm or 2 μm.

In some examples, a silicon dioxide layer in the composite dielectric film may be formed on the surface of the substrate 2, and a silicon nitride layer may be formed on the silicon dioxide layer. In other examples, the silicon dioxide layer may be formed by thermal oxidation and the silicon nitride layer may be formed by plating, spin coating, evaporation, printing, or extrusion.

In some examples, in step S10, as shown in fig. 6a, a sacrificial layer 4 may be formed on the first dielectric film 3 a. In addition, in some examples, the sacrificial layer 4 may be made of at least one selected from aluminum, silicon oxide, chromium, titanium. In other examples, the sacrificial layer 4 may be formed on the first dielectric film 3a by sputtering or evaporation. For example, a sacrificial aluminum film may be formed as the sacrificial layer 4 on the first dielectric film 3a by evaporation or sputtering of aluminum.

In some examples, in step S10, patterning the sacrificial layer 4 and etching to form a recess 4a for marking may be further included, and the position of the recess 4a may correspond to the position of the first window 111. Thereby, the subsequent etching of the first window 111 can be facilitated. In addition, a plurality of grooves 4a may be formed on the sacrificial layer 4, and one groove 4a may correspond to one first window 111. Further, the recess 4a may penetrate the sacrificial layer 4.

In some examples, the patterning of the sacrificial layer 4 may employ a photolithographic process. Specifically, photoresist may be spin-coated on the surface of the sacrificial layer 4, exposed by using a mask plate having a predetermined pattern, etched (for example, etched by an etchant or a metal etcher) after development, and photoresist removed (for example, wet photoresist removed), and then the patterned sacrificial layer 4 is obtained. However, examples of the present disclosure are not limited thereto, and in other examples, the patterning process of the sacrificial layer 4 may be patterned using other patterning methods, such as surface modification or printing.

In some examples, optionally, the photoresist is spin coated on the sacrificial layer 4 at a spin coating speed of 3000rmp to 4000rmp for 30s to 60s, followed by pre-baking at 90 ℃ to 100 ℃ for 1min to 2min, then exposing (ultraviolet light, 365nm to 406 nm) through a mask plate with a prescribed pattern for 5s to 10s, developing, then placing at 100 ℃ to 110 ℃ for film curing for 1min to 2min, then etching with an etching solution (e.g. aluminum etching solution) or a metal etching machine to form the grooves 4a, then removing the photoresist by wet method, and finally spin-drying to obtain the patterned sacrificial layer 4.

In some examples, in step S10, as shown in fig. 6b, a first insulating layer 11 may be formed on the patterned sacrificial layer 4. In other words, the first insulating layer 11 may cover the sacrificial layer 4. In addition, the first insulating layer 11 may also fill the grooves 4a on the sacrificial layer 4.

In addition, in some examples, the first insulating layer 11 is optionally formed on the patterned sacrificial layer 4 by plating, spin coating, evaporation, printing, or extrusion. In other examples, the first insulating layer 11 may be formed by curing under an inert gas or nitrogen atmosphere (such as vacuum nitrogen atmosphere).

In some examples, in step S10, the thickness of the first insulating layer 11 may be 4 μm to 7 μm. In other examples, the first insulating layer 11 may be composed of a flexible insulating material. This can reduce damage to the living body.

In some examples, the flexible insulating material may be at least one of polyimide, polyethylene terephthalate, parylene, silicone, polydimethylsiloxane, polymethyl methacrylate, polyethylene glycol, or polytetrafluoroethylene resin. Thereby, the double-sided electrode 1 having biocompatibility can be prepared.

In some examples, in step S10, a flexible insulating material (e.g., polyimide) may be spin coated on the patterned sacrificial layer 4 at a spin speed of 3000 to 4000rmp for 30 to 40S (e.g., 35S) and then placed in a vacuum nitrogen oven to cure, forming the first insulating layer 11 of 5 to 6 μm.

In some examples, in step S20, as shown in fig. 6b, the first conductive layer 21 may be formed on the first insulating layer 11, and the first conductive layer 21 may be formed in a first predetermined pattern.

In some examples, in step S20, forming a patterned protective layer on the first insulating layer 11 and removing the protective layer after forming the first conductive layer 21 may be further included, thereby forming the first conductive layer 21 in a first predetermined pattern. Thereby, the first conductive layer 21 in the first predetermined pattern can be prepared.

In some examples, a patterned photoresist layer may be formed on the first insulating layer 11. Specifically, photoresist (e.g., positive, negative, reverse, or double-layer photoresist with a spin-coating speed of 3000 to 4000rmp for 30 to 60 seconds) may be spin-coated on the first insulating layer 11 first, and then the photoresist layer may be exposed (e.g., ultraviolet light of 365 to 406nm for 5 to 10 seconds) using a mask having a first predetermined pattern, developed, and the first predetermined pattern is formed on the photoresist layer.

In some examples, the first conductive layer 21 may be formed on the surface of the photoresist layer having the first predetermined pattern using evaporation, sputtering, plating, or the like, and then the photoresist layer may be peeled off to obtain the first conductive layer 21 in the first predetermined pattern. In addition, residual metal outside the first predetermined pattern on the photoresist layer may be removed by stripping the photoresist layer.

In some examples, the first conductive layer 21 may be composed of a metallic material. In addition, in some examples, the metallic material may be selected from at least one of silver, platinum, gold, titanium, palladium, iridium, niobium. Thereby, the double-sided electrode 1 having biocompatibility can be prepared.

In some examples, the first conductive layer 21 may be a composite metal layer, which may be composed of at least two metal materials, such as a titanium-platinum-titanium structure, a titanium-gold-titanium structure, a niobium-gold-niobium structure, and the like. In addition, in some examples, the composite metal layer may be formed by sequentially evaporating, sputtering, or plating using various metal materials, for example, titanium, platinum, titanium may be sequentially sputtered to form a titanium-platinum-titanium structure.

In some examples, the thickness of the first conductive layer 21 may be 400nm to 600nm. In other examples, the thickness of the upper metal layer may be 30nm to 100nm, the thickness of the middle metal layer may be 100nm to 300nm, and the thickness of the lower metal layer may be 30nm to 100nm in the composite metal layer. For example, in a titanium-platinum-titanium structure, the thickness of the titanium metal layer may be 30nm to 100nm, the thickness of the platinum metal layer may be 100nm to 300nm, and the thickness of the titanium metal layer may be 30nm to 100nm.

In some examples, the first predetermined pattern may include a plurality of first electrode stimulation points 211, a plurality of first connection lines 212, and a plurality of first welding points 213. In addition, the plurality of first electrode stimulation points 211 may be connected to the plurality of first welding points 213 via the plurality of first connection lines 212, respectively.

In some examples, the first predetermined pattern may be composed of a plurality of first electrode stimulation points 211, a plurality of first connection lines 212, and a plurality of first welding points 213 connected to the plurality of first electrode stimulation points 211 via the plurality of first connection lines 212, respectively.

In some examples, in step S20, as shown in fig. 6c, the second insulating layer 12 may be formed on the first insulating layer 11 and the first conductive layer 21. Thereby, the first insulating layer 11 and the first conductive layer 21 can be covered. In addition, in some examples, the second insulating layer 12 may be formed on the first insulating layer 11 and the first conductive layer 21 in a plating, spin coating, evaporation, printing, or extrusion manner. In other examples, the second insulating layer 12 may be formed by curing under an inert gas atmosphere (e.g., vacuum nitrogen atmosphere).

In some examples, in step S20, the thickness of the second insulating layer 12 may be 4 μm to 7 μm. In other examples, the second insulating layer 12 may be composed of a flexible insulating material. This can reduce damage to the living body. In addition, the first insulating layer 11 and the second insulating layer 12 may be made of the same or different flexible insulating materials.

In some examples, in step S20, a flexible insulating material (e.g., polyimide) may be spin coated at a spin speed of 3000 to 4000rmp for 30 to 40S (e.g., 35S) and then placed in a vacuum nitrogen oven to cure, forming the second insulating layer 12 of 5 to 6 μm.

In some examples, in step S30, as shown in fig. 6c, the second conductive layer 22 may be formed on the second insulating layer 12, and the second conductive layer 22 may be formed in a second predetermined pattern T.

In some examples, in step S30, forming a patterned capping layer on the second insulating layer 12 and removing the capping layer after forming the second conductive layer 22 may further be included, thereby forming the second conductive layer 22 in the second predetermined pattern T. Thereby, the second conductive layer 22 in the second predetermined pattern T can be simply prepared.

In some examples, a patterned photoresist layer may be formed on the second insulating layer 12. Specifically, photoresist (e.g., positive, negative, reverse, or double-layer photoresist with a spin-coating speed of 3000 to 4000rmp for 30 to 60 seconds) may be spin-coated on the second insulating layer 12 first, and then the photoresist layer may be exposed (e.g., ultraviolet light of 365 to 406nm for 5 to 10 seconds) using a reticle having a second predetermined pattern T, developed, and the second predetermined pattern T is formed on the photoresist layer.

In some examples, the second conductive layer 22 may be formed on the surface of the photoresist layer having the second predetermined pattern T using evaporation, sputtering, plating, or the like, and then the photoresist layer may be stripped to obtain the second conductive layer 22 in the second predetermined pattern T. In addition, the remaining metal outside the second predetermined pattern T on the photoresist layer may be removed by stripping the photoresist layer.

In some examples, the second conductive layer 22 may be composed of a metallic material. In other examples, the second conductive layer 22 may be a composite metal layer. In addition, the first conductive layer 21 and the second conductive layer 22 may be made of the same or different metal materials.

In some examples, the thickness of the second conductive layer 22 may be 400nm to 600nm. In addition, the thicknesses of the first conductive layer 21 and the second conductive layer 22 may be the same or different.

In some examples, the second predetermined pattern T may include a plurality of second electrode stimulation points 221, a plurality of second connection lines 222, and a plurality of second welding points 223. In addition, the plurality of second electrode stimulation points 221 may be connected to the plurality of second pads 223 via the plurality of second connection lines 222, respectively.

In some examples, the second predetermined pattern T may be composed of a plurality of second electrode stimulation points 221, a plurality of second connection lines 222, and a plurality of first welding points 213 connected to the plurality of second electrode stimulation points 221 via the plurality of second connection lines 222, respectively.

In some examples, in step S30, as shown in fig. 6d, a third insulating layer 13 may be formed on the second insulating layer 12 and the second conductive layer 22. Thereby, the second insulating layer 12 and the second conductive layer 22 can be covered. In addition, in some examples, the third insulating layer 13 may be formed on the second insulating layer 12 and the second conductive layer 22 in a plating, spin coating, evaporation, printing, or extrusion manner. In other examples, the third insulating layer 13 may be formed by curing under an inert gas atmosphere (e.g., vacuum nitrogen atmosphere).

In some examples, in step S30, the thickness of the third insulating layer 13 may be 4 μm to 7 μm. In other examples, the third insulating layer 13 may be composed of a flexible insulating material. This can reduce damage to the living body. In addition, the second insulating layer 12 and the third insulating layer 13 may be made of the same or different flexible insulating materials. In addition, the first insulating layer 11, the second insulating layer 12, and the third insulating layer 13 may be made of the same or different flexible insulating materials.

In some examples, in step S30, a flexible insulating material (e.g., polyimide) may be spin coated at a spin speed of 3000 to 4000rmp for 30 to 40S (e.g., 35S) and then placed in a vacuum nitrogen oven to cure, forming the third insulating layer 13 of 5 to 6 μm.

In some examples, as described above, the first, second and third insulating layers 11, 12 and 13 may be respectively made of flexible insulating materials, which may be at least one of polyimide, polyethylene terephthalate, parylene, silicone, polydimethylsiloxane, polymethyl methacrylate, polyethylene glycol or polytetrafluoroethylene resin, and the first and second conductive layers 21 and 22 may be respectively made of metallic materials, which may be at least one of silver, platinum, gold, titanium, palladium, iridium, niobium. Thereby, the double-sided electrode 1 having biocompatibility and good electric conductivity can be produced.

In some examples, in step S40, as shown in fig. 6d, the mask layer 5 may be formed on the third insulating layer 13 by evaporation or sputtering. In other examples, the mask layer 5 may be one selected from photoresist, aluminum, silicon oxide, chromium, titanium. For example, a duralumin layer may be formed as the mask layer 5 on the third insulating layer 13 by evaporation or sputtering of aluminum.

In some examples, the third insulating layer 13 may be subjected to a cleaning process before forming the mask layer 5. In addition, the third insulating layer 13 may be subjected to plasma treatment, whereby the bonding between the third insulating layer 13 and the mask layer 5 can be enhanced.

In some examples, in step S40, the pattern of the mask layer 5 may be formed via a photolithography process. Specifically, photoresist (for example, positive photoresist, negative photoresist, reverse photoresist or double-layer photoresist with a spin-coating speed of 3000rmp to 4000rmp for 30s to 60 s) may be spin-coated on the surface of the mask layer 5, then exposure (for example, ultraviolet light of 365nm to 406nm, exposure for 5s to 10 s) may be performed by using a mask plate with a specific pattern, etching (for example, metal etching machine etching) after development and photoresist removal (for example, wet photoresist removal) may be performed, and then the patterned mask layer 5 may be obtained.

In some examples, as shown in fig. 6d, the pattern of the mask layer 5 may include a first score 5a for marking the second window 131, a second score 5b for marking the second channel 132, and a third score 5c for marking the first channel 133. In addition, the mask layer 5 may include a plurality of first grooves 5a, a plurality of second grooves 5b, and a plurality of third grooves 5c thereon. In addition, one first notch 5a may correspond to one second window 131, one second notch 5b may correspond to one second channel 132, and one third notch 5c may correspond to one first channel 133.

In some examples, in step S40, the second window 131, the second channel 132, and the first channel 133 may be formed by etching (e.g., reactive ion dry etching) according to the pattern on the mask layer 5. For example, as shown in fig. 6e, the second windows 131, the second channels 132, and the first channels 133 may be etched according to the first, second, and third grooves 5a, 5b, and 5c on the mask layer 5, respectively.

In some examples, the second window 131 may extend through the third insulating layer 13. In addition, the plurality of second electrode stimulation points 221 may correspond to the plurality of second windows 131 such that the plurality of second electrode stimulation points 221 are exposed to the outside through the plurality of second windows 131 to form the front-side electrode array P.

In some examples, the second channel 132 may extend through the third insulating layer 13. In addition, the plurality of second pads 223 may correspond to the plurality of second channels 132 such that the plurality of second pads 223 are exposed to the outside through the plurality of second channels 132 to form a second pad 223 array.

In some examples, the first channel 133 may extend through the second insulating layer 12 and the third insulating layer 13. In addition, the plurality of first pads 213 may correspond to the plurality of first channels 133 such that the plurality of first pads 213 are exposed to the outside through the plurality of first channels 133 to form a first pad 213 array. In addition, the first pad array R and the second pad array Q may be located on the same side as the front side electrode array P.

In some examples, as shown in fig. 6d, the pattern of the mask layer 5 may further include scribe lines 5d for the shape of the marks, thereby enabling the subsequent dicing to form the desired double-sided electrode 1.

In some examples, in step S50, the second dielectric film 3b may be subjected to patterning processing using a photolithography process. Specifically, a photoresist (for example, a positive photoresist, a negative photoresist, a reverse photoresist, or a double-layer photoresist at a spin-on speed of 3000rmp to 4000rmp for 30s to 60 s) may be spin-coated on the second dielectric film 3b, followed by exposure (for example, exposure to ultraviolet light of 365nm to 406nm for 5s to 10 s), development and film hardening (for example, film hardening baking at 100 ℃ to 110 ℃ for 1min to 2 min), followed by etching (for example, inductively coupled plasma dry etching machine etching) to form a back deep trench etching opening, and then photoresist stripping (for example, dry photoresist stripping) to obtain the patterned second dielectric film 3b.

In some examples, in step S50, deep trench vias may be formed by etching the substrate 2 according to the backside deep trench etch openings on the second dielectric film 3 b. In other examples, the substrate 2 may be etched using a silicon deep trench etcher to form deep trench vias.

In some examples, in step S50, etching the first dielectric film 3a according to the deep trench via on the substrate 2 may form an etched opening, so that the recess 4a on the sacrificial layer 4 may be exposed. Thereby, the first insulating layer 11 filled in the recess 4a of the sacrificial layer 4 can be exposed. In addition, in some examples, the etched openings may expose all of the grooves 4a on the sacrificial layer 4.

In some examples, in step S50, etching the first insulating layer 11 exposed in the etching opening may form the first window 111. In other examples, the first insulating layer 11 exposed in the etching opening may be optionally etched using a reactive ion dry etching machine to form the first window 111.

In some examples, the first window 111 may extend through the first insulating layer 11. In other examples, the plurality of first electrode stimulation points 211 may correspond to the plurality of first windows 111 such that the plurality of first electrode stimulation points 211 are exposed to the outside via the plurality of first windows 111 to form the backside electrode array. In addition, the front-side electrode array P may be opposite to the back-side electrode array.

In some examples, in step S50, removing the sacrificial layer 4 and the mask layer 5 may be further included to obtain the double-sided electrode 1. For example, the sacrificial aluminum film and the duralumin layer may be etched away using an aluminum etchant to obtain the double-sided electrode 1. In addition, the substrate 2 can be removed by removing the sacrifice layer 4.

In some examples, dicing may be performed using a dicing saw according to the dicing grooves 5d of the mask layer 5 before the sacrificial layer 4 and the mask layer 5 are removed.

In some examples, a single substrate 2 may simultaneously prepare a plurality of prepared double-sided electrodes 1, and a single double-sided electrode 1 may be formed by dicing.

In some examples, if the first conductive layer 21 and the second conductive layer 22 are, for example, titanium-platinum-titanium (Ti-Pt-Ti) structures, the double-sided electrode 1 after the substrate 2 is removed may be treated with hydrofluoric acid (HF) to etch away the surface titanium metal layer. Thereby, the exposed first electrode stimulation points 211, second electrode stimulation points 221, first pads 213, and second pads 223 can be made better in electrical conductivity.

In this embodiment, the preparation method of the double-sided electrode 1 can be compatible with the MEMS process, and the mature process with high repeatability and yield adopted in the preparation method is beneficial to mass production.

According to the present disclosure, an implantable double-sided electrode 1 having a simple process and a method for manufacturing the same can be provided.

While the disclosure has been described in detail in connection with the drawings and examples, it is to be understood that the foregoing description is not intended to limit the disclosure in any way. Modifications and variations of the present disclosure may be made as desired by those skilled in the art without departing from the true spirit and scope of the disclosure, and such modifications and variations fall within the scope of the disclosure.

Claims

1. An implantable double-sided electrode having a front side and a back side opposite the front side, characterized in that,

comprising the following steps:

a first insulating layer having a plurality of first windows penetrating the first insulating layer;

a first conductive layer disposed on the first insulating layer and formed in a first predetermined pattern including a plurality of first electrode stimulation points, a plurality of first connection lines, and a plurality of first solder joints connected to the plurality of first electrode stimulation points via the plurality of first connection lines, respectively;

a second insulating layer formed on the first conductive layer and covering the first insulating layer and the first conductive layer;

a second conductive layer disposed on the second insulating layer and formed in a second predetermined pattern including a plurality of second electrode stimulation points, a plurality of second connection lines, and a plurality of second solder joints connected to the plurality of second electrode stimulation points via the plurality of second connection lines, respectively; and

A third insulating layer formed on and covering the second conductive layer and the second insulating layer, and having a plurality of second windows penetrating the third insulating layer,

wherein the first electrode stimulation points correspond to the first windows so that the first electrode stimulation points are exposed to the outside through the first windows to form a back electrode array, the second electrode stimulation points correspond to the second windows so that the second electrode stimulation points are exposed to the outside through the second windows to form a front electrode array opposite to the back electrode array,

the first welding spots correspond to the first channels, the first channels penetrate through the second insulating layer and the third insulating layer, the second welding spots correspond to the second channels, the second channels penetrate through the third insulating layer,

the first welding spots are respectively exposed to the outside through the first channels to form a first welding disc array, the second welding spots are respectively exposed to the outside through the second channels to form a second welding disc array, and the first welding disc array and the second welding disc array are positioned on the same side with the front side electrode array.

2. The double-sided electrode according to claim 1, wherein,

the front side electrode arrays and the back side electrode arrays are staggered with each other in an imaginary electrode array formed by orthographic projection of the front side electrode arrays.

3. The double-sided electrode according to claim 1 or 2, wherein,

the front electrode array and the back electrode array are arranged in the same arrangement mode, distances between adjacent second electrode stimulation points in the front electrode array are equal to each other, and distances between adjacent first electrode stimulation points in the back electrode array are equal to each other.

4. The double-sided electrode according to claim 1, wherein,

the first insulating layer and the second insulating layer are fused with each other, the second insulating layer and the third insulating layer are fused with each other, and the first conductive layer and the second conductive layer are insulated from each other via the second insulating layer.

5. The double-sided electrode according to claim 1, wherein,

the distance between the front-side electrode array and the second pad array is smaller than the distance between the back-side electrode array and the first pad array.

6. The double-sided electrode according to claim 1, wherein,

the double-sided electrode comprises an implantation end, a connecting part and a welding end connected with the implantation end through the connecting part, the front-side electrode array and the back-side electrode array are positioned at the implantation end, and the second bonding pad array and the first bonding pad array are positioned at the welding end.

7. A preparation method of an implantable double-sided electrode is characterized in that,

the method comprises the following steps:

(a) Preparing a substrate having a first dielectric film and a second dielectric film opposite to each other, forming a sacrificial layer on the first dielectric film, and forming a first insulating layer on the sacrificial layer;

(b) Forming a first conductive layer in a first predetermined pattern on the first insulating layer, and then forming a second insulating layer on the first conductive layer and covering the first insulating layer and the first conductive layer, the first predetermined pattern including a plurality of first electrode stimulation points, a plurality of first connection lines, and a plurality of first solder joints connected to the plurality of first electrode stimulation points via the plurality of first connection lines, respectively;

(c) Forming a second conductive layer in a second predetermined pattern on the second insulating layer, and then forming a third insulating layer on the second conductive layer and covering the second insulating layer and the second conductive layer, the second predetermined pattern including a plurality of second electrode stimulation points, a plurality of second connection lines, and a plurality of second solder joints connected to the plurality of second electrode stimulation points via the plurality of second connection lines, respectively;

(d) Forming a patterned mask layer on the third insulating layer and etching according to the pattern on the mask layer, so as to form a plurality of second windows, a plurality of second channels and a plurality of first channels; and is also provided with

(e) Patterning and etching the second dielectric film to form a plurality of first windows to obtain the double-sided electrode,

wherein the first window penetrates through the first insulating layer, the first channel penetrates through the second insulating layer and the third insulating layer, the second window and the second channel respectively penetrate through the third insulating layer,

the first electrode stimulation points correspond to the first windows so that the first electrode stimulation points are exposed to the outside through the first windows to form a back electrode array, the second electrode stimulation points correspond to the second windows so that the second electrode stimulation points are exposed to the outside through the second windows to form a front electrode array opposite to the back electrode array,

the first welding spots correspond to the first channels, the first welding spots are exposed to the outside through the first channels to form a first welding disc array, the second welding spots correspond to the second channels, the second welding spots are exposed to the outside through the second channels to form a second welding disc array, and the first welding disc array and the second welding disc array are positioned on the same side with the front side electrode array.

8. The method according to claim 7, wherein,

in the step (a), patterning treatment is further performed on the sacrificial layer, and grooves for marking are formed by etching, wherein the positions of the grooves correspond to the positions of the first windows.

9. The method according to claim 7, wherein,

in the step (b), the method further includes forming a patterned protective layer on the first insulating layer, and removing the protective layer after forming the first conductive layer, thereby forming the first conductive layer in a first predetermined pattern.

10. The method according to claim 7, wherein,

the first insulating layer, the second insulating layer and the third insulating layer are respectively made of flexible insulating materials, the flexible insulating materials are at least one of polyimide, polyethylene terephthalate, parylene, silicone resin, polydimethylsiloxane, polymethyl methacrylate, polyethylene glycol or polytetrafluoroethylene resin,

the first conductive layer and the second conductive layer are respectively made of metal materials, the metal materials are at least one of silver, platinum, gold, titanium, palladium, iridium and niobium,

The sacrificial layer is made of at least one selected from aluminum, silicon oxide, chromium and titanium.