TW201827798A - Pressure sensors and manufacturing method thereof - Google Patents

Abstract

A pressure sensor and a manufacturing method thereof are provided. The pressure sensor includes a thin film transistor (TFT) array and a pressure-sensitive layer covering the TFT array. The pressure-sensitive layer includes a plurality of one dimensional materials arranged on the same plane or two dimensional materials, and a plurality of insulating layers. The insulating layers and the one or two dimensional materials are alternately stacked so as to effectively enhance the pressure resolution.

Description

Pressure sensor and method of manufacturing same

The present invention relates to a pressure sensing technique, and more particularly to a pressure sensor and a method of manufacturing the same.

In the prior art, the pressure sensitive layer in the pressure sensor is mostly formed by mixing conductive particles in a resin, which can be used as a pressure sensitive layer by reducing the thickness and reducing the output resistance when pressed. . However, since the conductive property of the conductive particles has no directivity, in addition to the resistance change in the pressed region, the uncompressed region is also easily affected, resulting in deterioration of the pressure resolution. Therefore, how to improve the aforementioned problems of the pressure sensor to provide excellent resolution is a subject of current important research and development.

The invention provides a pressure sensor capable of effectively improving pressure resolution.

The invention further provides a pressure sensor, which can also effectively improve the pressure resolution.

The invention further provides a method for manufacturing a pressure sensor, which can produce a pressure sensor with high pressure resolution.

A pressure sensor of the present invention includes a thin film transistor array and a pressure sensitive layer covering the thin film transistor array. Wherein, the pressure sensitive layer comprises a plurality of one-dimensional materials arranged in the same plane and a plurality of insulating layers, and the one-dimensional material and the insulating layer are alternately stacked.

Another pressure sensor of the present invention includes a thin film transistor array and a pressure sensitive layer covering the thin film transistor array. Wherein, the pressure sensitive layer comprises a plurality of two-dimensional materials and a plurality of insulating layers, and the two-dimensional material and the insulating layer are alternately stacked.

In the above embodiment of the invention, the pressure sensitive layer may be of a sense resistor type.

In an embodiment of the invention, the one-dimensional material may have a diameter of 5 nm to 100 nm.

In an embodiment of the invention, the one-dimensional material may have an aspect ratio greater than 100.

In an embodiment of the invention, the one-dimensional material may comprise a metal nanowire, a carbon nanotube or a metal oxide semiconductor.

In an embodiment of the invention, the metal of the metal nanowire may comprise gold, silver or copper.

In an embodiment of the invention, the metal oxide semiconductor may include zinc oxide, titanium oxide, tungsten oxide, molybdenum oxide, vanadium oxide, copper oxide, nickel oxide, cobalt oxide, iron oxide or tin oxide.

In another embodiment of the invention, the two-dimensional material may comprise graphene oxide or molybdenum disulfide.

A method of fabricating a pressure sensor of the present invention includes forming a thin film transistor array and forming a pressure sensitive layer on the thin film transistor array by 3D printing. The pressure sensitive layer includes a plurality of alternating layers of insulating layers and a plurality of one-dimensional materials or a plurality of two-dimensional materials arranged in the same plane.

Based on the above, the pressure sensor of the present invention makes the conductive structure in the pressure sensitive layer become directional conductive by providing alternately stacked insulating layers and one-dimensional materials or two-dimensional materials arranged in the same plane in the pressure sensitive layer. Layer to increase the pressure resolution of the pressure sensor.

The above described features and advantages of the invention will be apparent from the following description.

1 is a perspective view of a pressure sensor in accordance with an embodiment of the present invention.

Please refer to Figure 1. A pressure sensor 100 of the present embodiment includes a thin film transistor array 102 and a pressure sensitive layer 104 covering the thin film transistor array 102. The pressure sensitive layer 104 is, for example, a sense resistor type.

Hereinafter, the detailed structure of the pressure sensor of FIG. 1 and its embodiment will be exemplarily described with reference to FIGS. 2A and 2B.

Please refer to Figure 2A first. The pressure sensor 100 of the present embodiment includes a thin film transistor array 102 and a pressure sensitive layer 104 covering the thin film transistor array 102. The pressure sensitive layer 104 includes a plurality of one-dimensional materials 206 and a plurality of insulating layers 208 arranged in the same plane, and the one-dimensional material 206 and the insulating layer 208 are alternately stacked such that the one-dimensional material between the layers 206 will not touch each other.

In this embodiment, the one-dimensional material has a diameter of usually 5 nm to 100 nm, preferably 20 nm to 80 nm, more preferably 40 nm to 60 nm. Further, in terms of good electrical conductivity, the length of the one-dimensional material is not particularly limited as long as the aspect ratio of the one-dimensional material is more than 100. For example, the one-dimensional material may comprise a metal nanowire, a carbon nanotube, or a metal oxide semiconductor. The metal of the metal nanowire may include gold, silver or copper, but is not limited thereto. The metal oxide semiconductor may include zinc oxide, titanium oxide, tungsten oxide, molybdenum oxide, vanadium oxide, copper oxide, nickel oxide, cobalt oxide, iron oxide or tin oxide, but is not limited thereto.

In FIGS. 2A and 2B, only two adjacent thin film transistor elements (first thin film transistor element 210, second thin film transistor element 212) are illustrated for convenience of explanation, but it should be understood that the thin film transistor array More thin film transistor elements may be included, and are not limited to the numbers shown in Figure 2A or Figure 2B.

When no pressure is applied, as shown in FIG. 2A, between the first thin film transistor element 210 and the one-dimensional material 206 on the second thin film transistor element 212 is separated by an insulating layer 208, and current is difficult to pass between them. , so it presents a state of high resistance. When a pressure 214 is applied to a region of the first thin film transistor element 210, as shown in FIG. 2B, the pressure sensitive layer 104 on the first thin film transistor element 210 is deformed by being pressed, such that the distance between the one-dimensional materials 206 Shortening, current is easily transferred between the one-dimensional materials 206, and the resistance of the pressure-sensitive layer 104 is lowered. While the pressure-sensitive layer 104 on the second thin film transistor element 212 is also deformed by the pressure 214, since it is not directly at the point of application, even if deformation occurs, the one-dimensional material 206 having the directivity is It is not easy to contact, so the pressure sensitive layer 104 in the region 216 away from the point of application still maintains high resistance. Therefore, the present invention can provide a better pressure resolution than the prior art in which the pressure sensitive layer is formed by the conductive particles, and can be applied to the pressure image sensing technology such as fingerprint recognition and foot pressure sensing, but not Limited to this. The invention can be used wherever pressure sensing is desired.

In addition, the one-dimensional material 206 may be replaced by a two-dimensional material (not shown), and the two-dimensional material and the insulating layer 208 are alternately stacked to form a sensing layer. The two-dimensional material may include, but is not limited to, graphene oxide or molybdenum disulfide (MoS ₂ ). Since the structure of the two-dimensional material can also be alternately stacked with the insulating layer 208 so that the two-dimensional materials between the layers do not contact each other, the embodiment thereof is similar to the one-dimensional material, and therefore will not be described again.

Hereinafter, a method of manufacturing a pressure sensor according to another embodiment of the present invention will be described. Please refer to FIG. 3.

First, step 300 is performed to form a thin film transistor array, and the manner of forming the thin film transistor array can be any known manufacturing method.

Then, step 302 is performed to form a pressure sensitive layer on the thin film transistor array by 3D printing, the pressure sensitive layer comprising a plurality of alternating layers of insulating layers and one-dimensional materials or two-dimensional materials arranged in the same plane. The one-dimensional material and the two-dimensional material can be referred to the above embodiments, and therefore will not be described again. In the case where the pressure sensitive layer is a one-dimensional material, the insulating layer and the one-dimensional material are alternately formed on the thin film transistor array, so that the one-dimensional material of the layer and the layer are not pressed without being contacted. And after the pressure layer is subjected to a certain degree of pressure, the current can be transferred between the one-dimensional materials, and the resistance of the pressure sensor is changed (reduced).

In the case where the pressure sensitive layer includes a two-dimensional material, the insulating layer and the two-dimensional material are alternately formed on the thin film transistor array, and the result is also the same as the pressure sensitive layer formed by the one-dimensional material.

Further, the method of forming the pressure-sensitive layer may be a roll-to-roll manufacturing method such as screen printing or gravure printing in addition to 3D printing.

In summary, the pressure sensor of the present invention can be improved by alternately stacking a plurality of one-dimensional materials and insulating layers arranged in the same plane in the pressure sensitive layer or by alternately stacking a plurality of two-dimensional materials and an insulating layer. Pressure resolution of the pressure sensor. This is because the current transfer between the one-dimensional materials or between the two-dimensional materials is directional, so the present invention can provide a better pressure resolution than the prior art in which the pressure-sensitive layers are formed of conductive particles.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the present invention, and any one of ordinary skill in the art can make some changes and refinements without departing from the spirit and scope of the present invention. The scope of the invention is defined by the scope of the appended claims.

100‧‧‧pressure sensor

102‧‧‧Thin-film array

104‧‧‧Inductive layer

206‧‧‧One-dimensional materials

208‧‧‧Insulation

210‧‧‧First Thin Film Silicon Element

212‧‧‧Second thin film transistor components

214‧‧‧ Pressure

216‧‧‧ area

300, 302‧‧‧ steps

1 is a perspective view of a pressure sensor in accordance with an embodiment of the present invention. 2A is a schematic cross-sectional view of the pressure sensor of FIG. 1 in an uncompressed condition. 2B is a schematic cross-sectional view of the pressure sensor of FIG. 2A under pressure. 3 is a flow chart showing the manufacturing process of a pressure sensor in accordance with another embodiment of the present invention.

Claims (15)

A pressure sensor comprising: a thin film transistor array; and a pressure sensitive layer covering the thin film transistor array, wherein the pressure sensitive layer comprises a plurality of one-dimensional materials arranged in the same plane and a plurality of insulating layers The one-dimensional material and the insulating layer are alternately stacked. The pressure sensor of claim 1, wherein the pressure sensitive layer is of a sense resistor type. The pressure sensor of claim 1, wherein the one-dimensional material has a diameter of 5 nm to 100 nm. The pressure sensor of claim 1, wherein the one-dimensional material has an aspect ratio greater than 100. The pressure sensor of claim 1, wherein the one-dimensional material comprises a metal nanowire, a carbon nanotube or a metal oxide semiconductor. The pressure sensor of claim 5, wherein the metal of the metal nanowire comprises gold, silver or copper. The pressure sensor according to claim 5, wherein the metal oxide semiconductor comprises zinc oxide, titanium oxide, tungsten oxide, molybdenum oxide, vanadium oxide, copper oxide, nickel oxide, cobalt oxide, iron oxide or Tin oxide. A pressure sensor comprising: a thin film transistor array; and a pressure sensitive layer covering the thin film transistor array, wherein the pressure sensitive layer comprises a plurality of two-dimensional materials and a plurality of insulating layers, the two-dimensional The material and the insulating layer are alternately stacked. The pressure sensor of claim 8, wherein the two-dimensional material comprises graphene oxide or molybdenum disulfide. The pressure sensor of claim 8, wherein the pressure sensitive layer is of a sense resistor type. A method of manufacturing a pressure sensor, comprising: forming a thin film transistor array; and forming a pressure sensitive layer on the thin film transistor array by 3D printing, the pressure sensitive layer comprising a plurality of insulating layers stacked alternately And a plurality of one-dimensional materials or a plurality of two-dimensional materials arranged in the same plane. The method of manufacturing a pressure sensor according to claim 11, wherein the one-dimensional material has a diameter of 5 nm to 100 nm. The method of manufacturing a pressure sensor according to claim 11, wherein the one-dimensional material has an aspect ratio of more than 100. The method of manufacturing a pressure sensor according to claim 11, wherein the one-dimensional material comprises a metal nanowire, a carbon nanotube or a metal oxide semiconductor, and the two-dimensional material comprises a graphene oxide. Or molybdenum disulfide. The method of manufacturing a pressure sensor according to claim 14, wherein the metal of the metal nanowire comprises gold, silver or copper, and the metal oxide semiconductor comprises zinc oxide, titanium oxide, tungsten oxide, Molybdenum oxide, vanadium oxide, copper oxide, nickel oxide, cobalt oxide, iron oxide or tin oxide.