CN112604153A

CN112604153A - Electrode, circuit board and electronic equipment

Info

Publication number: CN112604153A
Application number: CN202011457341.3A
Authority: CN
Inventors: 戴聿昌; 庞长林
Original assignee: Intellimicro Medical Co ltd
Current assignee: Intellimicro Medical Co ltd
Priority date: 2020-12-10
Filing date: 2020-12-10
Publication date: 2021-04-06
Anticipated expiration: 2040-12-10

Abstract

The application discloses an electrode, a circuit board and an electronic device. The electrode is used as a stimulating electrode and/or a sensing electrode, and comprises: a substrate having an opening; a first pattern layer located within the substrate; and a second pattern layer located on the first pattern layer, wherein the opening exposes the upper surface of the second pattern layer, the first pattern layer and the second pattern layer are both metal layers, and the area of the first pattern layer is different from that of the second pattern layer so as to form a stepped structure. A stepped structure is formed between the first pattern layer and the second pattern layer of the electrode, so that the substrate wraps the first pattern layer and the second pattern layer more tightly, the bonding strength between the first pattern layer and the substrate and the bonding strength between the second pattern layer and the substrate are high, the reliability of the electrode is improved, and the service life of the electrode is prolonged. In addition, the area of the first pattern layer is smaller than that of the second pattern layer, so that the first pattern layer positioned below is protected and prevented from being corroded by corrosive body fluid.

Description

Electrode, circuit board and electronic equipment

Technical Field

The invention relates to the technical field of medical equipment, in particular to an electrode, a circuit board and electronic equipment.

Background

With the increasing level of technology, Implantable Medical Devices (IMDs) are increasingly used in the Medical field. An implantable medical device is a medical device implanted in the body of a patient to realize treatment of diseases and recovery of sensory functions, and an implanted device having an electrical stimulation function is gradually and widely adopted in the field of medical devices.

For example, electrical stimulation of the cochlea results in auditory recovery, electrical stimulation of the retina or visual cortex results in visual recovery, stimulation of the spinal cord to treat pain, and electrical stimulation of the deep brain to treat diseases such as epilepsy, parkinson's disease, depression, and the like. In an implant device of the above type, a stimulation electrode is typically provided, which comprises a substrate and a metal layer formed on the substrate, the exposed portion of the metal layer delivering electrical stimulation pulses to the implanted tissue.

In the process of implantation surgery, the stimulation electrode needs to be clamped and displaced frequently, so that the stimulation electrode inevitably rubs with external tools and human tissues, and the stimulation electrode is easy to damage; in addition, the stimulation electrode is exposed to the complex environment in the body during use, and is corroded by corrosive body fluid for a long time, so that the stimulation electrode can also fail. Therefore, it is a challenge for those skilled in the art to improve the stability and reliability of the stimulation electrode, and to ensure the bonding strength and lifetime between the metal layer and the substrate. In addition, sensing electrodes having a similar structure to the aforementioned stimulating electrodes for sensing biological signals of human organs are also widely used and also face stability and reliability problems to be solved.

Disclosure of Invention

In view of the above problems, it is an object of the present invention to provide an electrode, a circuit board, and an electronic apparatus, which have high bonding strength between a metal layer and a substrate, thereby improving reliability and life of the electrode.

According to a first aspect of the present invention, there is provided an electrode for use as a stimulating electrode and/or a sensing electrode, comprising: a substrate having an opening; a first pattern layer located within the substrate; and the second pattern layer is positioned on the first pattern layer, and the opening exposes the upper surface of the second pattern layer, wherein the first pattern layer and the second pattern layer are both metal layers, and the area of the first pattern layer is different from that of the second pattern layer so as to form a stepped structure.

Preferably, the area of the first pattern layer is smaller than the area of the second pattern layer.

Preferably, the first pattern layer is circular or regular polygonal, and the second pattern layer includes a central region, which is circular or regular polygonal.

Preferably, the second pattern layer further comprises a plurality of spaced vanes attached to the periphery of the central region.

Preferably, each said blade is of generally T-shaped configuration.

Preferably, the first pattern layer comprises a gold layer and the second pattern layer comprises a platinum layer.

Preferably, a seed layer is further included between the substrate and the lower side of the first pattern layer.

Preferably, the second pattern layer further includes a platinum ash layer on the platinum layer, and the opening exposes at least a part of a surface of the platinum ash layer.

According to a second aspect of the present invention, there is provided a circuit board having a lead-in terminal, an electrode terminal including the electrode as described above, and a connection portion connected between the lead-in terminal and the electrode terminal.

According to a third aspect of the present invention, there is provided an electronic apparatus comprising: an electrode as described above; or a circuit board as described above; the electronic equipment is brain-computer interface equipment, an artificial cochlea implant, a retina stimulation visual prosthesis, a cortex stimulator, a spinal cord stimulator or a brain pacemaker.

According to the electrode, the circuit board and the electronic device, the stepped structure is formed between the first pattern layer and the second pattern layer, so that the substrate wraps the first pattern layer and the second pattern layer more tightly, the first pattern layer and the second pattern layer are not easy to separate from the substrate, the bonding strength between the first pattern layer and the substrate and the bonding strength between the second pattern layer and the substrate are high, and the reliability and the service life of the electrode are improved.

Furthermore, the area of the first pattern layer is smaller than that of the second pattern layer, so that the first pattern layer is protected; further, the first pattern layer of the electrode in the technical scheme is circular or regular polygon, the second pattern layer comprises a central area, the central area is circular or regular polygon, and the center of the first pattern layer is coincident with the center of the second pattern layer, so that the electrode has good stability.

Furthermore, the second pattern layer of the electrode in the technical scheme is provided with the central area and the blades located around the central area, so that the bonding strength between the second pattern layer and the substrate is improved, when the blades are approximately T-shaped, the concave-convex connection structure is arranged between the second pattern layer and the substrate, the contact area between the second pattern layer and the substrate is increased, and the bonding strength between the second pattern layer and the substrate is further improved.

Drawings

The above and other objects, features and advantages of the present invention will become more apparent from the following description of the embodiments of the present invention with reference to the accompanying drawings, in which:

FIG. 1 shows an exploded view of an electrode according to an embodiment of the invention;

FIG. 2 illustrates a perspective view of a circuit board according to an embodiment of the present invention;

FIG. 3a shows a top view of an electrode according to an embodiment of the invention;

FIG. 3b shows a top view of an electrode according to another embodiment of the invention;

FIG. 4 illustrates a top view of a circuit board according to an embodiment of the present invention;

FIG. 5 illustrates a state diagram of an implanted electronic device according to an embodiment of the present invention;

fig. 6a to 6h respectively show sectional views of stages of a method of manufacturing a circuit board according to an embodiment of the present invention.

List of reference numerals

10 support substrate

20 first photoresist layer

30 second photoresist layer

40 third photoresist layer

100 circuit board

101 substrate

101a bottom thin film insulating layer

101b top thin film insulating layer

110 lead-in end

111 through hole

120 connecting part

130 electrode terminal

131 opening

132a first pattern layer

132b seed layer

133 second pattern layer

133a platinum layer

133b platinum Gray layer

140 electronic package

200 human tissue

Detailed Description

Various embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Like elements in the various figures are denoted by the same or similar reference numerals. For purposes of clarity, the various features in the drawings are not necessarily drawn to scale.

The following detailed description of embodiments of the present invention is provided in connection with the accompanying drawings and examples.

Fig. 1 shows an exploded view of an electrode according to an embodiment of the invention. The electrode is used as a stimulating electrode and/or a sensing electrode, realizes the function of disease treatment or rehabilitation through electrical stimulation when being used as the stimulating electrode, and can collect electrophysiological signals of human or animal tissues when being used as the sensing electrode. The electrode includes a substrate 101, a first pattern layer 132a, and a second pattern layer 133, the substrate 101 has an opening 131, the first pattern layer 132a is located in the substrate 101, and the second pattern layer 133 is located on the first pattern layer 132a, so that the opening 131 exposes the upper surface of the second pattern layer 133 (see fig. 2 and 3a and 3 b). The area of the first pattern layer 132a is different from the area of the second pattern layer 133, so as to form a stepped structure.

Preferably, as shown in fig. 3b, the area of the first pattern layer 132a is smaller than that of the second pattern layer 133, so as to protect the underlying first pattern layer 132 a. For example, the first pattern layer 132a has a circular or regular polygonal shape (e.g., not less than 12 sides), the second pattern layer 133 includes a central region having a circular or regular polygonal shape, and the central region of the second pattern layer 133 is larger than the circular or regular polygonal shape of the first pattern layer 132 a. Preferably, the center of the first pattern layer 132a coincides with the center of the second pattern layer 133, and the second pattern layer 133 entirely covers the first pattern layer 132a, so that the formed electrode has good stability. In this embodiment, the second pattern layer 133 can protect the first pattern layer 132a from being corroded by the corrosive body fluid after being implanted into the human body.

It should be noted that, in the exemplary embodiments of fig. 1 to 3a, the area of the first pattern layer 132a is larger than that of the second pattern layer 133, so as to be suitable for a specific usage scenario. The technical effects of the present invention can be also achieved when the area of the first pattern layer 132a is smaller, and furthermore, the material of the first pattern layer 132a has more possible choices because it is protected.

In the above embodiment, since the stepped structure is formed between the first pattern layer 132a and the second pattern layer 133, and the substrate 101 wraps the first pattern layer 132a and the second pattern layer 133 more tightly, the first pattern layer 132a and the second pattern layer 133 are not easily separated from the substrate 101, and the bonding strength between the first pattern layer 132a and the substrate 101 and the second pattern layer 133 is high, so that the electrode has good reliability and long service life.

In a preferred embodiment, the second pattern layer 133 further includes a plurality of spaced-apart fins connected to the outer periphery of the central region, and the regions between adjacent fins are bonded to the substrate 101, thereby further improving the bonding strength. The blade preferably has a substantially T-shaped structure, so that the connection structure between the second pattern layer 133 and the substrate 101 is a matching concave-convex connection structure, which increases the contact area between the second pattern layer 133 and the substrate 101 and further improves the bonding strength between the second pattern layer 133 and the substrate 101.

In addition, when the area of the first pattern layer 132a is smaller than the area of the central region of the second pattern layer 133, the spacing regions formed between the plurality of "T" shaped blades of the second pattern layer 133 are through up and down, so that the bottom substrate and the top substrate are directly combined in the spacing regions, the substrate 101 is greatly enhanced to wrap the first pattern layer 132a and the second pattern layer 133, the combination strength is improved, and the reliability of the electrode is increased.

In order to provide the electrical stimulation or sensing function of the electrode, the first pattern layer 132a and the second pattern layer 133 are both metal layers, the first pattern layer 132a and the second pattern layer 133 may be the same or different, and the material of the first pattern layer 132a and the second pattern layer 133 may be, for example, one or more selected from gold, silver, platinum, palladium, titanium, iridium oxide, carbon nanotubes, Conductive Polymer (Conductive Polymer), and an alloy or mixture thereof, such as electroplated platinum (including a (bright) platinum layer, a platinum gray layer, or a platinum black layer formed by electroplating) or a platinum-iridium alloy. The conductive polymer may be one or more of polypyrrole (polypyrole), polythiophene (polythiophene), or polyethylene dioxythiophene (poly-3,4-ethylene dioxythiophene).

Preferably, the first pattern layer 132a includes a gold layer having an extension portion for receiving an electrical stimulation pulse or transmitting an electrical sensing signal, and the second pattern layer 133 includes a platinum layer 133 a. Preferably, the second pattern layer 133 further includes a platinum gray layer 133b on the platinum layer 133a, the opening 131 exposes at least a portion of the surface of the platinum gray layer 133b, and the size of the opening 131 is preferably smaller than that of the second pattern layer 133. The platinum gray layer 133b has the same pattern as the platinum layer 133 a. Referring to fig. 3b, it is preferable that the second pattern layer 133 also has an extended portion covering the extended portion of the first pattern layer 132a thereunder to protect the portion of the first pattern layer 132a (e.g., gold layer, etc.).

The first pattern layer 132a (such as a gold layer and the like) has high electrical conductivity, less heat generation, low energy consumption, good flexibility, and is friendly to implanted tissues, the platinum layer 133a has high stability, long-time corrosion resistance and high mechanical strength, and the platinum ash layer 133b has a large specific surface area, so that the electrical impedance can be increased, and further the electrode has the capability of applying larger stimulation or sensing current, therefore, the electrode reasonably combines the advantages of various materials, not only ensures good stimulation or sensing effect, but also reduces the heat productivity and energy consumption of the electrode, has good mechanical strength, and prolongs the service life of the product. In addition, since it is preferable that the area of the first pattern layer 132a is smaller than that of the second pattern layer 133, the platinum ash layer 133b and the platinum layer 133a can protect the first pattern layer 132a thereunder.

Further, a seed layer 132b is further included between the substrate 101 and the bottom of the first pattern layer 132a, and the seed layer 132b may be a platinum seed layer, a titanium/platinum stack seed layer (titanium under layer), or a titanium/gold stack seed layer (titanium under layer) so as to improve the bonding strength between the first pattern layer 132a and the substrate 101. In addition, in this embodiment, the seed layer 132b is used to provide a good conductive layer for the electroplating process, and is formed by a physical deposition process, such as sputtering (sputter) or electron beam evaporation (E-beam). The seed layer 132b has a shape corresponding to the larger of the first and second pattern layers 132a and 133.

In addition, a strengthening layer (not shown) may be formed on the upper surface of the extended portion of the gold layer, and platinum or titanium may be used as the strengthening layer to strengthen the bonding strength between the gold layer and the top substrate. The thickness of the stiffening layer is lower than the thickness of the gold layer, but the pattern may be the same as the pattern of the gold layer.

Preferably, the substrate 101 includes a bottom thin film insulating layer 101a and a top thin film insulating layer 101b, and the first pattern layer 132a and the second pattern layer 133 are located between the bottom thin film insulating layer 101a and the top thin film insulating layer 101 b. The material of the bottom thin film insulating layer 101a and the top thin film insulating layer 101b is, for example, any one or more of PMMA (poly (methyl methacrylate)), teflon, silicone, polyimide, polyethylene terephthalate (poly (ethylene terephthalate)), and Parylene (especially Parylene-C). Preferably, the substrate 101 is made of parylene, and the thickness of the electrode can be as thin as tens of micrometers by using parylene, which is more flexible and convenient for plastic deformation, and can be better attached to the implanted tissue, thereby improving the electrical stimulation or sensing effect of the electrode.

Fig. 2 illustrates a perspective view of a circuit board according to an embodiment of the present invention. The circuit board 100 has a lead-in terminal 110, an electrode terminal 130, and a connection part 120 connected between the lead-in terminal 110 and the electrode terminal 130, and the electrode terminal 130 includes electrodes as shown in fig. 1, preferably, a plurality of electrodes arranged in a regular array.

In this embodiment, the lead-in 110 is used to connect electronic components; the connection portion 120 is internally formed with a wire; the electrode terminal 130 internally includes a wire electrode connected to the connection part 120. Among them, the lead of the connection part 120 and the first pattern layer 132a (see fig. 1) of the electrodes are preferably formed at the same time, for example, the first pattern layer 132a of the electrodes extends to the connection part 120 and the lead-in terminal 110 to provide electrical connection between the electronic component and the electrodes. Preferably, the first pattern layer 132a of the electrode and the wire of the connection part 120 each include a gold layer.

For example, the through hole 111 of the lead-in terminal 110 is filled with a conductive material, so that the lead-in terminal 110 and the electronic component can be electrically connected, thereby implementing an electrical stimulation or sensing loop between the electronic component connected to the lead-in terminal 100 and the electrode terminal 130.

For clarity and simplicity, only one circuit in circuit board 100 is shown in fig. 2. It should be understood that the present application is not limited thereto, and the circuit board 100 may include a plurality of circuits.

Fig. 3a shows a top view of an electrode according to an embodiment of the invention. As shown in fig. 3a, in this embodiment, two electrodes are schematically illustrated, and preferably, a common substrate 101 is used for the two electrodes, a first pattern layer 132a and a second pattern layer 133 on the first pattern layer 132a are respectively formed in different areas in the substrate 101, the substrate 101 has an opening 131 to expose the second pattern layer 133, and the second pattern layer 133 includes a central area and a plurality of mutually spaced blades connected to the periphery of the central area, which is beneficial to further improve the bonding strength between the second pattern layer 133 and the substrate 101. For clarity, the substrate 101 overlying the first patterned layer 132a and the second patterned layer 133 is omitted from the electrodes in the dashed box in fig. 3 a.

Fig. 3b shows a top view of an electrode according to another embodiment of the invention. Unlike fig. 3a, the first pattern layer 132a and the second pattern layer 133 have different shapes and relative sizes. For clarity, the substrate 101 overlying the second patterned layer 133 is omitted from the electrodes in the dashed box in fig. 3 b.

Fig. 4 shows a top view of a circuit board according to an embodiment of the invention. As shown in fig. 4, in this embodiment, a plurality of through holes 111 are included at the lead-in end 110; a plurality of wires are formed in the connection portion 120, and the wires may be formed in one layer or a plurality of layers in the height direction; the electrode terminal 130 includes a plurality of openings, which respectively expose the second pattern layers 133 of the plurality of electrodes, and the plurality of electrodes are arranged in a regular array.

FIG. 5 shows a state diagram of an implanted electronic device according to an embodiment of the invention. In this embodiment, the electronic device includes an electrode or circuit board 100 as shown in fig. 1-4. The electronic device preferably further includes an electronic component connected to the lead-in 110, and the lead-in 110 is connected to one or more electronic components, such as circuit chips, capacitors, inductors, resistors, oscillators, filters, memories, and the like, which may be provided according to circuit design, thereby forming the electronic package 140.

The electronic device is applicable to, for example, a brain-machine interface device, a cochlear implant, a retinal implant, a visual cortex implant, a spinal cord stimulator (for treating pain), a deep brain stimulator (brain pacemaker), and the like. In fig. 5, the installation and use of the electronic device is schematically illustrated by taking the visual cortical implant as an example.

In the process of installing the visual cortex implant, the human tissue 200 is first processed, for example, a part of the skull is first removed to form a hollow part, then the electrode tip 130 is implanted into the surface of the visual cortex, and the electronic package 140 is implanted into the hollow part of the skull, or the upper part of the skull and the lower part of the scalp. Generally, the electrode tip 130 may be implanted in the V1 region of the visual cortex, or may partially cover the V2 or V3 regions. It should be noted that the V1, V2 and V3 regions of the visual cortex of the brain mentioned here are the common divisions of the brain in the field of vision and will not be explained in detail here.

During use of the visual cortical implant, communication is made between the visual cortical implant and an external device. More specifically, the external device includes a camera for collecting video information, the video information is wirelessly transmitted to the electronic package 140 of the implant device after data conversion, and the electrode of the electrode terminal 130 transmits stimulation to the visual cortex in an electrical stimulation manner, so that the patient can generate visual perception.

It should be understood that the installation and use of the electronic device are schematically described in this embodiment by taking the example of implanting the visual cortex implant into the visual cortex of the brain, but the application is not limited thereto, and the electronic device may also be used for other human tissues, for example.

The method starts with a support substrate 10 and a first photoresist layer 20 on the support substrate 10, as shown in fig. 6 a. The support substrate 10 is used to provide mechanical support, and the first photoresist layer 20 is used to protect the support substrate 10 and serves as a sacrificial layer in the step of releasing the circuit board 100. In an alternative embodiment, the first photoresist layer 20 may be omitted to reduce cost and simplify the process flow.

Further, a bottom thin film insulating layer 101a is formed on the first photoresist layer 20, as shown in fig. 6 b. In this step, it is preferable that the bottom thin film insulating layer 101a be a parylene film, and the parylene film is formed using a Chemical Vapor Deposition (CVD) process.

Preferably, a seed layer 132b is formed on the bottom thin film insulating layer 101a, as shown in fig. 6 c. The seed layer 132b may be a platinum seed, a titanium/platinum stack seed layer (titanium under layer), or a titanium/gold stack seed layer (titanium under layer). In this step, the seed layer 132b is formed, for example, using a Physical Vapor Deposition (PVD) process such as sputtering (sputter) or electron beam evaporation (E-beam), and the thickness of the seed layer 132b is preferably set to be equal to that of the seed layer 132b

The seed layer 132b covers the entire upper surface of the bottom thin film insulating layer 101a, for example, and the seed layer 132b is advantageous for a subsequent electroplating process and for enhancing the bonding strength between the bottom thin film insulating layer 101a and the first pattern layer 132 a.

Further, a patterned first pattern layer 132a is formed, as shown in fig. 6 d. In this step, for example, a second photoresist layer 30 is formed on the surface of the seed layer 132b, and the second photoresist layer 30 is exposed and developed to form a second photoresist layer 30 having a pattern, the pattern of the second photoresist layer 30 matching the pattern of the lead-in terminal 110, the connection part 120, and the electrode terminal 130 of the circuit board. After the second photoresist layer 30 is formed, the first pattern layer 132a filled in the pattern of the second photoresist layer 30 is formed, for example, a gold layer filled in the pattern of the second photoresist layer 30 is formed using a gold plating solution.

In this embodiment, the gold layer at the electrode terminal 130 forms a first pattern layer 132a of the electrode. Preferably, the thickness of the gold layer at the electrode tip 130 is preferably

Further, a second pattern layer 133 is formed on the surface of the first pattern layer 132a, as shown in fig. 6 e. In this step, for example, the second photoresist layer 30 is removed, then the third photoresist layer 40 is formed on the surface of the first pattern layer 132a, and the third photoresist layer 40 is exposed and developed to form the third photoresist layer 40 having a pattern, wherein the pattern of the third photoresist layer 40 matches the pattern of the second pattern layer 133. After the third photoresist layer 40 is formed, a second pattern layer 133 filled in the pattern of the third photoresist layer 40 is formed.

In this embodiment, the area of the first pattern layer 132a is different from the area of the second pattern layer 133, so that a stepped structure is formed between the first pattern layer 132a and the second pattern layer 133. The second pattern layer 133 is also a metal layer. Preferably, the second pattern layer 133 includes a platinum layer 133a, and the platinum layer 133a filled in the pattern of the third photoresist layer 40 is formed using, for example, a platinum plating solution.

In a preferred embodiment, the second pattern layer 133 further includes a platinum ash layer 133b, for example, the platinum ash layer 133b is formed on the surface of the platinum layer 133a, such that the platinum layer 133a and the platinum ash layer 133b are sequentially located above the first pattern layer 132 a. The thickness of the platinum layer 133a is preferably 3 to 7 μm, the thickness of the platinum ash layer 133b is preferably 0.5 to 4 μm, and the position of the platinum ash layer 133b corresponds to the position of the platinum layer 133 a.

The shapes of the first pattern layer 132a and the second pattern layer 133 are the same as those of the first pattern layer 132a and the second pattern layer 133 in the electrode shown in fig. 1 and fig. 3a or fig. 3b, and are not described again.

Further, in this step, for example, the third photoresist layer 40 is removed first, and then the seed layer 132b is subjected to a patterning process, so as to remove the excess seed layer, as shown in fig. 6 f. In this step, the exposed seed layer 132b is removed, for example, by a sputtering process, so as to prevent the excess seed layer from causing short circuit. The seed layer 132b has a shape corresponding to the larger of the first and second pattern layers 132a and 133.

Further, a top thin film insulation layer 101b covering the lead-in terminal 110, the connection part 120, and the electrode terminal 130 is formed as shown in fig. 6 g. In this step, the material of the top thin film insulating layer 101b is the same as that of the bottom thin film insulating layer 101a, and a parylene film is formed using a chemical vapor deposition process.

Further, the via hole 111 and the opening 131 are formed to form the circuit board 100, as shown in fig. 6 h. In this step, for example, a patterned mask (not shown) is formed on the top thin film insulating layer 101b, and an anisotropic dry etching process is used to form a via hole 111 in the top thin film insulating layer 101b and the bottom thin film insulating layer 101a corresponding to the lead-in terminal 110 and an opening 131 in the top thin film insulating layer 101b corresponding to the electrode terminal 130. In this embodiment, the portion of the circuit board 100 at the electrode end 130 is a stimulation electrode or a sensing electrode. Preferably, after the through hole 111 and the opening 131 are formed, the first photoresist layer 20 and the support substrate 10 are removed, for example, the first photoresist layer 20 is dissolved and removed, and the support substrate 10 is removed, followed by a water rinsing and baking step to clean the outer side surface of the circuit board 100.

After the circuit board 100 manufactured as described above is formed, the circuit board 100 is connected with electronic components, such as one or more electronic components that may be provided according to a circuit design, including circuit chips, capacitors, inductors, resistors, oscillators, filters, memories, etc., to form an electronic device, such as any one of a brain-computer interface device, an artificial cochlear implant, a retinal stimulating visual prosthesis, a cortical stimulator, a spinal stimulator, and a pacemaker.

In this embodiment, a manufacturing method of a circuit board is described as an example of a MEMS manufacturing process, but the manufacturing method of the circuit board of the present application is not limited thereto.

While embodiments in accordance with the invention have been described above, these embodiments are not intended to be exhaustive or to limit the invention to the precise embodiments described. Obviously, many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the invention and the practical application, to thereby enable others skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. An electrode for use as a stimulation electrode and/or a sensing electrode, comprising:

a substrate having an opening;

a first pattern layer located within the substrate; and

a second pattern layer on the first pattern layer, the opening exposing an upper surface of the second pattern layer,

the first pattern layer and the second pattern layer are both metal layers, and the area of the first pattern layer is different from that of the second pattern layer, so that a stepped structure is formed.

2. The electrode of claim 1, wherein the area of the first patterned layer is smaller than the area of the second patterned layer.

3. The electrode of claim 1, wherein the first patterned layer is circular or regular polygonal and the second patterned layer comprises a central region that is circular or regular polygonal.

4. The electrode of claim 3, wherein the second patterned layer further comprises a plurality of spaced vanes attached to the periphery of the central region.

5. The electrode of claim 4 wherein each of said vanes is generally T-shaped in configuration.

6. The electrode of any of claims 1-5, wherein the first patterned layer comprises a gold layer and the second patterned layer comprises a platinum layer.

7. The electrode of claim 6, further comprising a seed layer between the substrate and an underside of the first pattern layer.

8. The electrode of claim 6, wherein the second patterned layer further comprises a platinum gray layer over the platinum layer, the opening exposing at least a portion of a surface of the platinum gray layer.

9. A circuit board having a lead-in terminal, an electrode terminal, and a connecting portion connected between the lead-in terminal and the electrode terminal, the electrode terminal comprising the electrode according to any one of claims 1 to 8.

10. An electronic device, comprising:

an electrode according to any one of claims 1 to 8; or

The circuit board of claim 9;

the electronic equipment is brain-computer interface equipment, an artificial cochlea implant, a retina stimulation visual prosthesis, a cortex stimulator, a spinal cord stimulator or a brain pacemaker.