CN215219656U

CN215219656U - Capacitance induction device

Info

Publication number: CN215219656U
Application number: CN202120357881.8U
Authority: CN
Inventors: 林剑; 马昌期; 曾超; 邢建博
Original assignee: Suzhou Institute of Nano Tech and Nano Bionics of CAS
Current assignee: Guangdong Green Exhibition Technology Co ltd
Priority date: 2021-02-09
Filing date: 2021-02-09
Publication date: 2021-12-17
Anticipated expiration: 2031-02-09

Abstract

The utility model discloses a capacitance sensing device, which comprises a sensing layer, an insulating layer and an encapsulation layer, wherein the insulating layer is positioned between the sensing layer and the encapsulation layer, the sensing layer is a substrate and is used for contacting fingerprints, the sensing layer is positioned on the upper part of the insulating layer, and the encapsulation layer is positioned on the lower part of the insulating layer; the electrode is arranged in the insulating layer and is in contact with the sensing layer, and the connecting wire is arranged in the packaging layer and is connected with the electrode. Adopt the utility model discloses, have the sensitivity that improves electric capacity identification to be suitable for the advantage that requires higher application scene at resolution such as fingerprint identification.

Description

Capacitance induction device

Technical Field

The utility model relates to a fingerprint identification field especially relates to a capacitance sensing device.

Background

In the current fingerprint identification method, a mutual capacitance mode is adopted, namely the contact concave-convex difference of the finger is sensed through the change of the fringe capacitance value between the X/Y electrodes. Since the period of each capacitor unit is only 50 microns or less, the sensitivity requirement of the structure to capacitance change is much higher than that of a common touch screen.

In the conventional structure, a finger approaches from one side of a packaging layer and is detected, in the detection process, the interference of conductor components such as a via hole, a connecting line and the like on capacitance distribution is caused, and in order to reduce the interference as much as possible, the via hole and the connecting line can be thinned and reduced as much as possible, so that extra burden on the process is caused.

In addition, the dielectric constant of the encapsulation layer also affects the sensitivity, so that the material selection is limited, and the thickness of the encapsulation layer is also limited.

Therefore, a capacitive sensing device for fingerprint identification is provided, which can simplify the manufacturing process and improve the sensitivity of the capacitive identification, so that the capacitive sensing device can be applied to application scenes with higher requirements on resolution, such as fingerprint identification, and the like, to be solved.

Disclosure of Invention

The utility model aims to solve the technical problem that a capacitance sensing device is provided, can improve capacitance identification's sensitivity, be particularly suitable for and require higher application scene at resolution ratio such as fingerprint identification.

In order to solve the technical problem, the utility model provides a capacitance sensing device, which comprises a sensing layer, an insulating layer and an encapsulation layer, wherein the insulating layer is positioned between the sensing layer and the encapsulation layer, the sensing layer is a substrate and is used for contacting fingerprints, the sensing layer is positioned on the upper part of the insulating layer, and the encapsulation layer is positioned on the lower part of the insulating layer;

the electrode is arranged in the insulating layer and is in contact with the sensing layer, and the connecting wire is arranged in the packaging layer and is connected with the electrode.

Preferably, the sensing layer is a single-layer substrate, and the single-layer substrate is a glass substrate, a ceramic substrate, a silicon substrate, a polyacrylate substrate, a polyester substrate, a polyimide substrate, a polysiloxane film or a polyurethane film.

Preferably, the sensing layer is a multilayer substrate and comprises a first substrate layer and a second substrate layer;

one surface of the first substrate layer is in contact with the electrode, and the other surface of the first substrate layer is connected with the second substrate layer.

Preferably, the first substrate layer is a titanate film, a ceramic substrate or a metal oxide film;

the second substrate layer is a glass substrate, a ceramic substrate, a silicon substrate, a polyacrylate substrate, a polyester substrate, a polyimide substrate, a polysiloxane film or a polyurethane film.

Preferably, the total thickness of the sensing layer is 1-100 μm.

Preferably, the total thickness of the sensing layer is 10-50 μm.

Preferably, the thickness of the first substrate layer is 0.001-15 μm.

Preferably, the connecting wire is located below the electrode, and the connecting wire penetrates into the insulating layer and is connected with the electrode.

Preferably, the connection lines include a first connection line and a second connection line, the first connection line is disposed along the layer surface of the encapsulation layer, one end of the second connection line is connected to the first connection line, and the other end of the second connection line is connected to the electrode;

a via hole is formed in the bottom of the insulating layer, and the second connecting line is connected with the electrode through the via hole.

Preferably, the electrodes include a first electrode and a second electrode, and the first electrode and the second electrode are arranged side by side along the layer surface of the insulating layer, so that the first electrode and the second electrode are in contact with the sensing layer;

and a space is arranged between the first electrode and the second electrode, and the second connecting wire is connected with the second electrode.

Implement the utility model discloses, following beneficial effect has:

the utility model discloses a setting up the inductive layer that is used for contacting the fingerprint outwards, the inductive layer is located the upper portion of insulating layer, can reduce interference, improves the sensitivity of electric capacity discernment. The sensing layer for contacting the fingerprint is a substrate, and the influence of the dielectric constant of the packaging layer on the sensitivity can be avoided. And the electrode is contacted with the sensing layer, and the connecting wire is positioned below the electrode so as to reduce the influence of the connecting wire on the sensitivity of the sensing layer.

And simultaneously, the utility model discloses still reduced the requirement to the structure setting of insulating layer, encapsulated layer, electrode and connecting wire, simplified technology, change production, reduction in production cost.

In addition, the utility model discloses can adopt ultra-thin substrate as the response layer, its thickness can be as low as 1 mu m, can reduce the finger and by the distance between the electric capacity that forms between the electrode, further promote sensitivity.

Drawings

Fig. 1 is a structural diagram of a capacitance sensing device according to the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention clearer, the present invention will be described in further detail with reference to the accompanying drawings. Only this statement, the utility model discloses the upper and lower, left and right, preceding, back, inside and outside etc. position words that appear or will appear in the text only use the utility model discloses an attached drawing is the benchmark, and it is not right the utility model discloses a concrete restriction.

Combine fig. 1, the utility model provides a capacitance sensing device, including inductive layer 1, insulating layer 2 and encapsulated layer 3, insulating layer 2 is located between inductive layer 1 and the encapsulated layer 3, be equipped with electrode 21 in the insulating layer 2, electrode 21 with inductive layer 1 contacts, be equipped with connecting wire 31 in the encapsulated layer 3, connecting wire 31 penetrates in the insulating layer 2 and with electrode 21 is connected.

The utility model arranges the induction layer 1 used for contacting the fingerprint outwards, and the induction layer 1 is positioned on the upper part of the insulation layer 2, thereby reducing the interference and improving the sensitivity of capacitance identification; in addition, the sensing layer 1 for contacting the fingerprint is a substrate, so that the influence of the dielectric constant of the packaging layer 3 on the sensitivity can be avoided.

Specifically, the electrode 21 includes a first electrode 211 and a second electrode 212, the first electrode 211 and the second electrode 212 are arranged side by side along the layer surface of the insulating layer 2, so that the first electrode 211 and the second electrode 212 are in contact with the sensing layer 1, the distance between the finger and the electrode 21 is reduced, and the concave-convex difference of the finger fingerprint can be fed back more accurately by the capacitance change between the first electrode 211 and the second electrode 212, so as to facilitate fingerprint identification. And the packaging layer 3 is positioned at the lower part of the insulating layer 2, and the connecting wire 31 is positioned below the electrode 21, so that the influence of the dielectric constant of the connecting wire 31 in the packaging layer 3 on the sensitivity of the sensing layer 1 is reduced, meanwhile, the requirements on the structural arrangement of the insulating layer 2, the packaging layer 3, the electrode 21 and the connecting wire 31 are reduced, and the production is easier. Furthermore, the connection line 31 is connected to the second electrode 212 from the inside of the package layer 2 from bottom to top, so as to avoid the influence of the arrangement of the connection line 31 on the sensitivity of capacitance change in the electrode 21. Still further, there is a gap between the first electrode 211 and the second electrode 212 to form a mutual capacitance.

It should be noted that, because the electrode 21 is directly contacted with the sensing layer 1, the thickness of the insulating layer 2 and the material adopted by the insulating layer 2 do not affect the sensitivity of the electrode 21, and therefore, the insulating layer 2 can be coated with an insulating material to improve the service life of the product; the thickness of the insulating layer 2 can be smaller, equal or larger than the thickness of the sensing layer 1, so as to facilitate production and molding.

In a common capacitance device for identifying a fingerprint, since the connecting line 31 is disposed between the finger and the electrode 21, in order to suppress interference of the connecting line 31 on the sensitivity of the electrode 21, it is often necessary to reduce the occupied area of the connecting line 31 on the package layer 3; and the utility model discloses well electrode 21 is direct to contact with induction layer 1, and connecting wire 31 no longer causes the influence to electrode 21's sensitivity to the area occupied of encapsulated layer 3, connecting wire 31 promptly as long as with electrode 21 intercommunication and not short circuit can, can promote the yields, reduce cost by a wide margin to connecting wire 31's design requirement reduction. Further, the connection line 31 includes a first connection line 311 and a second connection line 312, the first connection line 311 is disposed along the layer of the package layer 2, one end of the second connection line 312 is connected to the first connection line 311, and the other end of the second connection line 312 is connected to the second electrode 212 from bottom to top; wherein, be equipped with via hole 22 in the bottom of insulating layer 2, second connecting wire 312 via hole 22 with electrode 21 is connected, the size restriction of via hole 22 is lower, as long as second connecting wire 312 can pass through, convenient production and manufacturing. Preferably, the thickness of the encapsulation layer 3 may be smaller than, equal to, or greater than the thickness of the sensing layer 1, so as to improve the yield and reduce the cost.

On the other hand, in order to further improve the sensitivity, the total thickness of the sensing layer 1 is 1-100 μm, and the ultra-thin sensing layer 1 is selected to reduce the distance between the finger and the capacitance formed between the electrodes 21. Preferably, the total thickness of the sensing layer 1 may be limited to 10-50 μm. Further preferably, the thickness of the sensing layer 1 may be limited to 20-30 μm.

The inductive layer 1 is a substrate, which may be composed of one or more layers.

Preferably, the sensing layer 1 is a single-layer substrate, and the single-layer substrate is a glass substrate, a ceramic substrate, a silicon substrate, a polyacrylate substrate, a polyester substrate, a polyimide substrate, a polysiloxane film, or a polyurethane film, but is not limited thereto.

Preferably, the sensing layer 1 is a multilayer substrate, and comprises a first substrate layer and a second substrate layer; one side of the first substrate layer is in contact with the electrode 21, and the other side of the first substrate layer is connected to the second substrate layer.

Wherein the first substrate layer is a titanate film, a ceramic substrate or a metal oxide film, but is not limited thereto. The first substrate layer is close to one side of the electrode 21, a titanate film, a ceramic substrate or a metal oxide film is selected, the dielectric constant is high, and the sensing effect is improved by matching with the thin thickness. Preferably, the thickness of the first substrate layer is 0.001-15 μm.

The second substrate layer is a glass substrate, a ceramic substrate, a silicon substrate, a polyacrylate substrate, a polyester substrate, a polyimide substrate, a polysiloxane film or a polyurethane film. The second substrate layer is mechanically stronger and more scratch resistant than the first substrate layer.

The working principle of the utility model is as follows:

the sensing layer 1 is located on the upper portion of the insulating layer 2, the packaging layer 3 is located on the lower portion of the insulating layer 2, the first electrode 211 and the second electrode 212 are in contact with the sensing layer 1, the connecting wire 31 is connected with the electrode 21, and the connecting wire 31 is located below the electrode 21. The finger touches the sensing layer 1, so that capacitance change occurs between the first electrode 211 and the second electrode 212, and the concave-convex difference of the finger fingerprint is fed back.

The foregoing is a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, a plurality of improvements and decorations can be made without departing from the principle of the present invention, and these improvements and decorations are also considered as the protection scope of the present invention.

Claims

1. A capacitance sensing device comprises a sensing layer, an insulating layer and a packaging layer, wherein the insulating layer is positioned between the sensing layer and the packaging layer;

2. The capacitive sensing device of claim 1 wherein the sensing layer is a single layer substrate, the single layer substrate being a glass substrate, a ceramic substrate, a silicon substrate, a polyacrylate substrate, a polyester substrate, a polyimide substrate, a polysiloxane film, or a polyurethane film.

3. The capacitive sensing device of claim 1 wherein said sensing layer is a multilayer substrate comprising a first substrate layer and a second substrate layer;

4. The capacitive sensing device of claim 3 wherein the first substrate layer is a titanate film, a ceramic film, or a metal oxide film;

5. The capacitive sensing device of claim 1 wherein the total thickness of the sensing layer is 1-100 μm.

6. The capacitive sensing device of claim 5 wherein the total thickness of the sensing layer is 10-50 μm.

7. The capacitive sensing device of claim 4 wherein the thickness of the first substrate layer is 0.001-15 μm.

8. The capacitive sensing device of claim 1 wherein said connecting wire is positioned below said electrode and wherein said connecting wire penetrates into said insulating layer and is connected to said electrode.

9. The capacitive sensing device of claim 8 wherein the connecting lines comprise a first connecting line and a second connecting line, the first connecting line being disposed along the layer of the encapsulation layer, one end of the second connecting line being connected to the first connecting line, the other end of the second connecting line being connected to the electrode;

10. The capacitive sensing device of claim 9 wherein said electrodes comprise a first electrode and a second electrode, said first and second electrodes being positioned side-by-side along the level of said insulating layer such that said first and second electrodes are in contact with said sensing layer;