KR101689769B1

KR101689769B1 - The multi-channel metal microneedle array electrode for biosignal measurement and the manufacturing method thereof

Info

Publication number: KR101689769B1
Application number: KR1020150134938A
Authority: KR
Inventors: 정완균; 김민재; 김동성; 김태완; 차경제
Original assignee: 포항공과대학교 산학협력단
Priority date: 2015-09-23
Filing date: 2015-09-23
Publication date: 2016-12-26

Abstract

The present invention relates to a metal needle array electrode for measuring a biometric signal, which includes a fixed layer that is in close contact with a body tissue on one surface thereof, a circuit board that is in close contact with the other surface of the fixed layer, and a plurality of metal needles which pass through the fixed layer and the circuit board, and each of which has an insertion part that protrudes from one surface of the fixed layer and is inserted into the body tissue when one surface of the fixed layer is in close contact with the body tissue, to receive an electric signal. The metal needle array electrode for measuring a biometric signal according to the present invention and the method for manufacturing the same may measure a biometric signal having low distortion by minimizing noise such as environment noise and operating noise by minimizing an interference between the needles, and may be used for a long time. Further, because a high spatial resolution is provided according to a configuration of electrodes, an electromyographic signal may be analyzed at a high depth.

Description

TECHNICAL FIELD [0001] The present invention relates to a multi-channel metal needle array electrode for measuring biological signals, and a method of manufacturing the same. BACKGROUND ART < RTI ID = 0.0 >

The present invention relates to a multi-channel metal needle array electrode for measuring biological signals, and more particularly, to a metal needle array electrode for measuring a biological signal such as an electromyogram and a core line inserted into a living tissue, &Lt; / RTI >

Electroencephalogram (electroencephalogram), electrocardiogram (electrocardiogram) and electromyogram (electromyogram) when you want to measure biological signals attached to the skin to measure the signal is required. At this time, the stratum corneum, which is the outer layer of the skin, has a very large impedance, so various techniques are applied to lower it. Conventionally, a method of lowering using a conductive gel is widely used. However, such a method has a limitation in that it can not be reliably measured for a long period of time due to evaporation of the gel and contamination during the operation.

To solve this problem, a method of receiving a signal by directly contacting a microneedle array with the skin layer under the stratum corneum using a microneedle array has been developed.

However, such a method based on silicon or polymer has a problem in that noises flow from the outside of the human body through the substrate because the conductivity of the substrate on which the needle is attached becomes conductive during the plating process for conductivity.

In addition, silicon and polymers were broken during signal measurement, which reduced the quality of the measured signal and posed the risk of causing irritation to the user.

[Prior Art 1] O'Mahony, Conor, et al. "Microneedle-based electrodes with integrated through-silicon via for biopotential recording." Sensors and Actuators A: Physical 186 (2012): 130-136.

[Prior Art 2] Lin, By Chin-Teng, et al. "Noninvasive neural prostheses using mobile and wireless EEG." Proceedings of the IEEE 96.7 (2008): 1167-1183.

An object of the present invention is to provide a metal needle array electrode and a manufacturing method thereof that solve the problem of external noise and breakage of the conventional needle array electrode.

According to an embodiment of the present invention, there is provided a method of manufacturing a semiconductor device, comprising the steps of: (1) inserting a fixing layer in contact with a living tissue on one side, a circuit board in close contact with the other side of the fixing layer, And a plurality of metal needles including a plurality of metal needles inserted into the living tissue and configured to receive an electric signal when one surface of the fixed layer is closely contacted with the living tissue to receive an electrical signal.

At this time, the plurality of metal needles may be electrically connected to the circuit board so that a signal generated from the living tissue upon insertion into the living tissue can be transmitted to the circuit board through the insertion unit.

On the other hand, the fixing layer may be made of a nonconductive material so that disturbance of an electric signal does not occur between a plurality of metal needles.

The plurality of metal needles are exposed through the circuit board on the other side of the inserting portion,

The fixture may be configured to secure the circuit board to the other side of the plurality of metal needles.

Furthermore, the plurality of metal needles are arranged in a direction in which the metal needles are parallel to each other, and the distance between adjacent metal needles can be configured to be sharper.

In this case, the insertion portion of the metal needle may have a length that does not irritate the nerves of the skin when the metal needle is inserted into the living tissue. Specifically, the insertion portion may have a length of 1 mm or less so as not to irritate nerves in the dermis of the skin have.

On the other hand, the other side of the plurality of metal needles may be a fixed portion, and may further include a fixture for fixing the fixed portion of the metal needle to the circuit board.

Furthermore, the circuit board may further include a shield portion configured not to be exposed to the outside.

According to another aspect of the present invention, there is provided a method of manufacturing a circuit board, comprising the steps of: creating a sacrificial layer; provisionally fixing a plurality of metal needles attached to a circuit board to a sacrificial layer; Attaching the circuit board and the plurality of metal needles to each other; And

A method of manufacturing a metal needle array electrode for measuring a biological signal including a step of removing a sacrificial layer can be provided.

At this time, the plurality of metal needles may be configured so that each metal needle is regularly arranged in a parallel direction.

On the other hand, the step of creating the sacrificial layer forms a sacrificial layer on one side of the wafer, and the step of removing the sacrificial layer can be removed together with the wafer.

The temporary fixing step may include a step of inserting a plurality of metal needles from one side of the sacrificial layer to one side of the wafer so that the length of the plurality of metal needles protruding can be determined according to the thickness of the sacrificial layer, As shown in FIG.

Here, the step of forming the sacrificial layer may determine the thickness of the sacrificial layer so that the protruding length of the plurality of metal needles is a length that does not irritate the nerves of the skin when inserted into the living tissue. Further, The thickness of the sacrificial layer may be less than 1 mm so as not to stimulate nerves in the dermis of the skin.

The step of forming the fixed layer may include forming a plurality of metal needles in a direction perpendicular to the parallel direction of the plurality of metal needles and applying and applying the liquid polymer to the other side of the wafer- And can be produced by curing.

The circuit board is attached to the plurality of metal needles so that the circuit board can move relative to the plurality of metal needles in the longitudinal direction. The step of bringing the circuit board into close contact with the fixing layer moves the circuit board in the longitudinal direction of the plurality of metal needles And can be configured to come into close contact with the fixed layer.

At this time, the circuit board may be configured such that a hole is formed in a thickness direction of the circuit board at a plurality of points corresponding to the arrangement of the plurality of metal needles, and a plurality of metal needles are inserted into the hole.

In addition, after the step of securing the circuit board and the plurality of metal needles, the method may further include the step of creating shielding so that the circuit board can be protected.

A metal needle array electrode for measuring a biological signal according to the present invention and a method of manufacturing the same can minimize a noise such as environmental noise and operation noise by minimizing inter-needle interference and measure a biological signal with less distortion, It is effective.

In addition, according to the structure of the electrode, since it has a high spatial resolution, there is an effect that a strong EMG signal analysis can be performed.

1 is a perspective view of a metal needle array electrode according to a first embodiment of the present invention.
2 is a sectional view of the first embodiment.
3 is a view showing an example of use of the first embodiment.
4 is a graph showing a bio-signal measured according to the number of needles in the first embodiment.
FIG. 5 is a graph showing a biomedical signal measured when the interval between needles of the first embodiment is narrow.
6 is a graph comparing signals of the conventional electrode and the conventional electrode.
7 is a perspective view showing a metal needle array electrode according to a second embodiment of the present invention.
8 is a flowchart of a method of manufacturing a metal needle array electrode according to a third embodiment of the present invention.
9 is a view showing a conceptual diagram according to the order of the third embodiment.

Hereinafter, a metal needle (4) array electrode and a method of manufacturing the same according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. In the following description of the embodiments, the names of the respective components may be referred to as other names in the art. However, if there is a functional similarity and an equivalence thereof, the modified structure can be regarded as an equivalent structure. In addition, reference numerals added to respective components are described for convenience of explanation. However, the contents of the drawings in the drawings in which these symbols are described do not limit the respective components to the ranges within the drawings. Likewise, even if the embodiment in which the structure on the drawing is partially modified is employed, it can be regarded as an equivalent structure if there is functional similarity and uniformity. Further, in view of the level of ordinary skill in the art, if it is recognized as a component to be included, a description thereof will be omitted.

1 is a perspective view of a metal needle (4) array electrode according to a first embodiment of the present invention.

As shown in the figure, the metal needle 4 array electrode according to the present invention may include a plurality of metal needles 4 protruding from one surface of the body 10.

The overall shape of the metal needle 4 array electrode may be a planar shape having a wide direction, and a plurality of metal needles 4 may protrude from a wide one surface of the outer surface.

When the metal electrodes 4 are used, the skin is brought into contact with the surfaces of the plurality of metal needles 4 protruded. The metal electrodes 4 are inserted into the skin of the protruded metal needles 4 to measure the biological signals.

In the arrangement of the plurality of metal needles 4, there is shown an example in which 16 needles are arranged at 4x4 at even intervals. The effect of forming a plurality of metal needles 4 will be described with reference to FIG.

On the other hand, the overall shape of the array of metal needles 4 is merely an example, and may be formed in various shapes including needles protruding from one surface. Meanwhile, the material of the body part 10 may be rigid or may be made of a flexible material so that contact with the human body can be optimized.

2 is a sectional view of the first embodiment.

As shown in the figure, the body part 10 of the metal needle 4 array electrode for measuring biological signals includes a fixed layer 2, a circuit board 3, a fixing body 5, a plurality of metal needles 4, And a shield (6).

1, one side of the body part 10 comes into contact with the living tissue, and one side of the fixing layer 2 comes into contact with the living tissue. The fixing layer 2 fixes the plurality of metal needles 4 and may be made of a non-conductive material so that electrical signals are not directly transmitted from the outside to the substrate.

On the other hand, the fixing layer 2 can firmly fix a plurality of metal needles 4, but it can be made of a flexible material as required.

The circuit board 3 is provided on the upper side of the fixing layer 2 with reference to Fig. 2, and a plurality of holes are formed in the thickness direction corresponding to the arrangement of the plurality of metal needles 4. A metal needle (4) is provided in each of the plurality of holes.

The circuit board 3 may be composed of a PCB substrate, and may include various circuits and semiconductors as required. Such a configuration can be variously configured according to the purpose of processing a signal and a signal to be measured, and is generally widely used, and thus a detailed description thereof will be omitted.

The plurality of metal needles (4) is constituted by an insertion portion (41) in which an area protruding outward of the fixed layer (2) is inserted into the tissue. The metal needle 4 is made of a conductive material so that it can pass through the stratum corneum and receive electrical signals in the skin.

The other side of the insertion portion 41 of the metal needle 4 penetrates the fixing layer 2 and the circuit board 3 in the thickness direction and is not electrically connected to the fixing layer 2 as described above, And is electrically connected through the substrate 3 and the fixture 5 to be described later.

When the needle is made of a metal to be inserted into the living body, it is possible to prevent breakage such as breakage of the needle in use, and to partially perform plating in order to electrically connect to the circuit board 3 The manufacturing time and cost can be reduced, and the durability can be ensured while enhancing the noise canceling performance.

Referring again to FIG. 2, four metal needles 4 are provided in a direction parallel to the longitudinal direction, and the distance between the metal needles 4 can be uniformly determined. The length of the metal needle 4 insertion portion 41 will be described later with reference to FIG.

The fixture 5 electrically connects the circuit board 3 and the plurality of metal needles 4 and serves to fix the metal needles 4 to the circuit board 3. [

The shield 6 is configured such that the components other than the contact surface contacting the skin of the fixed layer 2 and the insertion portion 41 of the metal needle 4 are not exposed to the outside. The shield 6 is provided with a non-conductive material so as to minimize noise from the outside, and is configured to protect the circuit board 3 and the components including the fixing portion.

On the other hand, the fixed body 5 and the protective shield 6 electrically connected to the circuit board 3 are generally widely used, and thus a detailed description thereof will be omitted.

3 is a view showing an example of use of the first embodiment. As shown in the figure, the metal needle 4 is inserted into the skin tissue by the contact of the metal electrode 4 with the skin. In general, it is preferable that the nerve N in the dermis of the skin S is present at less than 1 mm, so that the nerve N is not stimulated in order to minimize pain and pain. However, since it is desirable to insert a depth to receive a high-quality signal, the length of the insertion portion 41 may be less than 1 mm. In addition, the minimum length of the insertion portion 41 is preferably a minimum length that can be inserted into the stratum corneum layer to avoid a decrease in measured value due to a high impedance value in the stratum corneum layer.

On the other hand, the lengths of the insertion portions 41 of the plurality of metal needles 4 may be variously varied depending on the depth of the nerve.

4 is a graph showing a bio-signal measured according to the number of needles in the first embodiment.

As shown in the figure, measured EMG signals with different numbers of needles and electromyogram signals obtained by filtering EMG signals are shown.

If the electromyogram signal is discriminated on / off, it is preferable that the measured signal is clearly distinguished on / off. 4 (a), when the number of metal needles 4 is 1, 4, 9, 16, and the number of metal needles 4 is plural, when the distance between the electrodes is maintained at 20 mm And the number of on / off signals becomes clear and the noise decreases as the number increases. This also affects the value of filtering performed in Fig. 4 (b).

Noise in the vicinity of the metal electrode, for example, electromagnetic waves irradiated to the skin from a fluorescent lamp (60 Hz) may be transmitted through the skin when the biological signal is measured using the metal electrode, but the number of needles is large The impedance value between the ground electrode and the living body is reduced and the influence of the noise is reduced.

FIG. 5 is a graph showing a biomedical signal measured when the interval between needles of the first embodiment is narrow.

This graph shows a result graph obtained by removing the noise of 60 Hz by the measured biological signals and filtering when the distance between the metal needles 4 is 2 mm.

If the spacing of the metal needles 4 is reduced, the signal measurement can be made intensively in one area and the influence of signals generated in the surrounding tissues, such as the peripheral muscles, can be minimized. In addition, when the number of the metal needles 4 is increased from (a) to (c), the result is shown. When the number of the metal needles 4 is four as shown in Fig. 5 (c) The effect of noise was reduced.

However, the number and arrangement interval of the metal needles 4 described with reference to FIG. 4 and FIG. 5 may be various combinations depending on the body part to be measured.

6 is a graph comparing signals of the conventional electrode and the conventional electrode.

In this figure, a wet type using a conventional gel and a graph showing a measurement of an electromyogram by a flexor carpi radialis and an extensor carpi radialis as a first embodiment of the present invention are shown.

6 (a) and 6 (b) show the angle of the arm when the muscle is contracted and relaxed, and the EMG measured values are shown in (c) and (d).

At this time, each of the muscles is independently used during contraction and relaxation, and therefore, it is preferable that the signal measured at this time is clearly distinguished.

As shown in FIG. 6 (c), when the bio-signal is measured by the conventional method, it is apparent that distinction between shrinkage (F) and relaxation (E) is not clear because the EMG measurement signal contains much noise.

6 (d) is an electromyogram measured when the number of the metal needles 4 is 16 using the first embodiment, and the distinction between the time of contraction and the time of relaxation is clearly made, This is the result of minimizing the noise generated outside the muscle used.

7 is a perspective view showing a metal needle array electrode according to a second embodiment of the present invention. As shown in the figure, the present embodiment can include the same components as those of the first embodiment. In order to avoid redundant description, the description will be omitted and a description .

As shown in the figure, the metal needle array electrode according to the present invention may be composed of a plurality of electrodes, and may further include an amplifier.

Fig. 7 shows an electrode consisting of two metal needle arrays arranged in a 4x4 array. It is configured to be optimized for each site to be adhered for measurement. That is, each metal needle array can be configured in an optimized arrangement according to the shape, area, size, depth, etc. of the part to be measured, and the number of such electrodes can be modified and applied. Can be configured. On the other hand, a flexible material may be provided between the electrode and the electrode to facilitate adhesion to a wide area.

The amplifier 7 can be connected to the circuit board 3 to process measured values from the metal needles 3 and, if formed of a plurality of channels, can be configured to process a plurality of signals. In electromyogram signal processing, there is a difficulty in signal processing due to the motion artifact due to the movement of the wire connecting the electrode and the signal processing unit. Therefore, in order to minimize this, the amplifier 7 may be directly connected to the circuit board 3 to directly process the signal, minimize the noise, and transmit the processed signal to the outside. On the other hand, when the amplifier 7 is configured as described above, the amplifier 7 can be provided between the circuit board 3 and the shield 6. [

FIG. 8 is a flow chart of a method of manufacturing an array electrode of a metal needle 4 according to a third embodiment of the present invention, and FIG. 9 is a view showing a conceptual diagram in the order of the third embodiment.

As shown in the figure, the method for fabricating a metal needle 4 array electrode for biological signal measurement according to the present invention includes the steps of creating a sacrificial layer 1 (S100, FIG. 9 (a)), sacrificing a metal needle 4 (S200, Fig. 9 (b)) of hardening the sacrificial layer 1 (S250), (c) forming the fixed layer 2 9 (d)) of fixing the circuit board 3 and the plurality of metal needles 4 (S500, Fig. 9 (e), (S600, FIG. 9 (f)) of removing the sacrificial layer 1 and the wafer W (S700, FIG. 9 have.

The sacrificial layer 1 is formed by forming sacrificial layers 1 on one side of the wafer W and arranging a plurality of metal needles 4 on the sacrificial layer 1, And is made of a material that can be fixed.

The step of temporarily fixing the metal needle 4 to the sacrificial layer S200 (Fig. 9 (b)) is a step of fixing the metal electrode array attached to the circuit board 3 to the sacrificial layer 1. [ At this time, the metal needle 4 passes through the sacrificial layer 1, but does not pass through the wafer W, and only the thickness of the sacrificial layer 1 is invaded. The thickness of such an implanted metal needle 4 is then the length of the needle protruding from the body portion 10 of the metal needle 4 array electrode. At this time, the metal needle 4 array and the circuit board 3 are in the attached state, and the circuit board 3 can move in the longitudinal direction of the needle. At this time, in the holes formed in the thickness direction of the circuit board 3 The needle of which is made to penetrate.

The step of curing the sacrificial layer 1 (S250) is a step of hardening the sacrificial layer 1 so that the metal needle 4 described above can be securely fixed to the temporarily fixed position on the sacrificial layer 1. [ The method of curing may be performed in various ways depending on the material of the sacrificial layer 1. Since this structure is a commonly used technique, a detailed description will be omitted.

The step of forming the fixing layer 2 (S300, Fig. 9 (c)) is a step of forming a fixing layer 2 for fixing a plurality of metal needles 4 to the other surface of the cured sacrificial polymer. At this time, the fixed layer 2 is formed on one side of the sacrificial layer 1 between the circuit board 3 and the sacrificial layer 1. The fixing layer 2 may be formed by applying a liquid polymer to one side of the sacrificial layer 1 or the like. As the fixed layer 2 is formed and cured, the distance between the metal needles 4 is fixed, and the length protruding in the longitudinal direction is also fixed. Meanwhile, the fixed layer 2 may be made of a non-conductive material in order to minimize interference with signals received at each electrode. This fixed layer 2 is finally used as a surface which comes into contact with the skin.

9 (d)) in which the circuit board 3 is brought into close contact with the fixed layer 2 after the fixed layer 2 is cured, the circuit board 3 is brought into close contact with the fixed layer 2 Can be configured.

The step of fixing the circuit board 3 and the plurality of metal needles 4 (S500 and Fig. 9 (e)) is carried out after the circuit board 3 is brought into close contact with the circuits constituted on the circuit board 3, 4 are electrically connected and fixed. At this time, the fixing of the metal needles 4 and the circuit can be performed by applying various commonly used methods such as soldering or applying a conductive paste or the like to harden the circuit.

Then, a connector connected to an amplifier can be connected to the circuit board 3 to be connected to an external device.

The step of generating the shield 6 (S600, Fig. 9 (f)) is a step of shielding a portion excluding the electrode so as to protect the components including the circuit board 3 from the outside and minimize external noise .

The step of removing the sacrificial layer 1 and the wafer W (S700 and Fig. 9 (g)) removes the cured sacrificial layer 1 and the metal needles 4 are fixed by the sacrificial layer 1 The wafer W is also removed when the sacrificial layer 1 is removed.

As described above, the metal needle 4 is invaded on the sacrificial layer 1, and the fixing layer 2 is formed on one surface of the sacrificial layer 1, The thickness is determined. Therefore, the protruded length of the metal needle 4 is preferably 1 mm or less so as to minimize the influence on the nerves existing in the skin. Therefore, the thickness of the sacrificial layer 1 is preferably 1 mm or less.

As described above, according to the present invention, the metal needle array for measuring bio-signals and the method of manufacturing the same can minimize the influence of external noises by measuring bio-signals using a plurality of metal needle arrays Stable signal measurement is possible. It can reduce the pain of the patient by adjusting the length of the metal needle inserted into the skin. It can be used continuously for a long time without the use of gel. It can be used for durability by using metal needles. There is an effect.

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, . Therefore, it should be understood that the above-described embodiments are illustrative in all aspects and not restrictive. The scope of the present invention is defined by the appended claims rather than the detailed description and all changes or modifications derived from the meaning and scope of the claims and their equivalents are to be construed as being included within the scope of the present invention do.

W: Wafer
1: sacrificial layer
2: Fixed layer
3: Circuit board
4: Metal needles
41:
5: Fixture
6: Shield
10: Body part
S100: Step of creating a sacrificial layer
S200: temporarily fixing the metal needle to the sacrificial layer
S250: Step of hardening the sacrificial layer
S300: Step of creating a fixed layer
S400: Step of bringing the circuit board into close contact with the fixing layer
S500: fixing the circuit board and the plurality of metal needles
S600: Steps to create a shield
S700: removing sacrificial layer and wafer

Claims

A fixation layer in which one surface is in close contact with a living tissue;
A circuit board which is brought into close contact with the other surface side of the fixing layer; And
And an insertion portion provided through the fixing layer and the circuit board and protruding from one surface of the fixing layer and inserted into the living tissue when one surface of the fixing layer is in close contact with the living tissue to receive an electric signal, A metal needle array electrode for measuring biological signals comprising a plurality of metal needles.

The method according to claim 1,
Wherein the plurality of metal needles are electrically connected to the circuit board so that a signal generated from the living body tissue when inserted into the living tissue can be transmitted to the circuit board through the insertion unit. Needle array electrodes.

3. The method of claim 2,
Wherein the fixed layer is made of a nonconductive material so that disturbance of the electrical signal does not occur between the plurality of metal needles.

The method of claim 3,
Wherein the plurality of metal needles are exposed through the circuit board on the other side of the inserting portion,
Further comprising a fixture configured to fix the circuit board to the other side of the plurality of metal needles.

The method of claim 3,
Wherein the plurality of metal needles are arranged in a direction in which the metal needles are parallel to each other and a distance between adjacent metal needles is uniform.

The method of claim 3,
Wherein the insertion portion of the metal needle has a length that does not stimulate nerves of the skin when the metal needle is inserted into the living tissue.

The method according to claim 6,
Wherein the inserting portion is configured to have a length of 1 mm or less to prevent nerves in the dermis of the skin from being irritated.

3. The method of claim 2,
The other side of the plurality of metal needles is a fixed portion,
Further comprising a fixture for fixing the fixing portion of the metal needle to the circuit board.

3. The method of claim 2,
Further comprising a shield portion configured to prevent the circuit board from being exposed to the outside.

Creating a sacrificial layer;
Temporarily fixing a plurality of metal needles attached to a circuit board to the sacrificial layer;
Creating a fixed layer for fixing the temporarily fixed plurality of metal needles;
Adhering the circuit board to the fixing layer;
Fixing the circuit board and the plurality of metal needles; And
And removing the sacrificial layer from the sacrificial layer.

11. The method of claim 10,
Wherein the plurality of metal needles are regularly arranged in a direction parallel to each of the metal needles.

12. The method of claim 11,
Wherein forming the sacrificial layer comprises forming the sacrificial layer on one side of the wafer,
Wherein the step of removing the sacrificial layer is removed together with the wafer.

13. The method of claim 12,
Wherein the temporarily fixing comprises:
Inserting the plurality of metal needles from the sacrificial layer side to one side of the wafer so that the length of the plurality of metal needles protruded can be determined according to the thickness of the sacrificial layer,
Further comprising the step of curing the sacrificial layer after the provisional fixation. &Lt; Desc / Clms Page number 19 >

14. The method of claim 13,
Wherein forming the sacrificial layer comprises:
Wherein the thickness of the sacrificial layer is determined so that the projected length of the plurality of metal needles is such that the length of the protruded length of the plurality of metal needles does not irritate the nerves of the skin when inserted into the living tissue. .

15. The method of claim 14,
Wherein forming the sacrificial layer comprises:
Wherein the thickness of the sacrificial layer is formed to be 1 mm or less so that the length of the plurality of metal needles does not irritate nerves in the dermis of the skin.

14. The method of claim 13,
Wherein the step of generating the fixed layer comprises:
A plurality of metal needles are formed in a direction perpendicular to the parallel direction of the plurality of metal needles and are formed by coating and curing a liquid polymer on the other side of the surface of the sacrificial layer on which the wafer is adhered so as to fix the plurality of metal needles Wherein the electrodes of the electrodes are electrically connected to each other.

14. The method of claim 13,
Wherein the circuit board is attached to the plurality of metal needles such that the circuit board can move relative to the plurality of metal needles in the longitudinal direction,
Wherein the step of bringing the circuit board into close contact with the fixation layer moves the circuit board in the longitudinal direction of the plurality of metal needles to bring the fixture layer into close contact with the fixation layer.

17. The method of claim 16,
The circuit board includes:
Holes are formed in a thickness direction of the circuit board at a plurality of points corresponding to the arrangement of the plurality of metal needles,
And each of the plurality of metal needles is inserted into the hole.

14. The method of claim 13,
After fixing the circuit board and the plurality of metal needles,
Further comprising forming shielding to protect the circuit board. &Lt; Desc / Clms Page number 22 >