CN213812677U - Flexible pressure sensor - Google Patents

Abstract

The utility model discloses a flexible pressure sensor, including first circuit layer, second circuit layer and set up in first, the isolation layer between the second circuit layer, first circuit layer includes first substrate and forms front circuit and back circuit on the relative both sides face of first substrate respectively, the both ends of first substrate form induction zone and wiring district respectively, front circuit includes first induction line and the second induction line that is located induction zone, first lead wire and the second lead wire that is located wiring district, first lead wire and first induction line electric connection, the second lead wire and the electric connection of second induction line; the back circuit comprises a third lead and a fourth lead which are positioned in the wiring area, the third lead is electrically connected with the first lead, and the fourth lead is electrically connected with the second lead; second circuit range upon range of locates on the induction zone and towards first, second induction line setting, the diversification of being connected with external circuit is realized through the lead wire of both sides, has made things convenient for the utility model discloses flexible pressure sensor's installation is used.

Description

Flexible pressure sensor

Technical Field

The utility model relates to a sensor technical field especially relates to a flexible pressure sensor.

Background

Pressure sensors are typically constructed of a substrate having electrodes and a conductive membrane that are initially spaced apart to form a deformation cavity therebetween. When the pressure is applied, the conductive film deforms and is in contact conduction with the electrode, and along with the increase of the contact area of the conductive film and the electrode, the current between the conductive film and the electrode increases, so that the output resistance of the sensor is changed, and the relation between the pressure and the output resistance is obtained. Along with the development of the pressure sensor, the application of the pressure sensor is wider and wider, and the requirement is higher and higher, at present, the pressure sensor only leads out a lead on a front circuit layer to serve as an output end, and the pressure sensor cannot adapt to the requirement of a complex structure.

Disclosure of Invention

In view of the above, a flexible pressure sensor is provided that can be double-sided leaded to facilitate connection to external circuitry.

A flexible pressure sensor comprises a first circuit layer, a second circuit layer and an isolation layer arranged between the first circuit layer and the second circuit layer, wherein the first circuit layer comprises a first substrate, a front circuit and a back circuit which are respectively formed on two opposite side surfaces of the first substrate, two ends of the first substrate are respectively provided with a sensing area and a wiring area, the front circuit comprises a first sensing wire and a second sensing wire which are positioned in the sensing area, and a first lead and a second lead which are positioned in the wiring area, the first lead is electrically connected with the first sensing wire, and the second lead is electrically connected with the second sensing wire; the back surface circuit comprises a third lead and a fourth lead which are positioned in the wiring area, the third lead is electrically connected with the first lead, and the second lead is electrically connected with the fourth lead; the second circuit is arranged on the induction area in a stacked mode and faces the first induction line and the second induction line.

Furthermore, a through hole is formed in the first substrate, a conductive pillar is formed in the through hole, first via holes are respectively formed in the first lead and the third lead corresponding to the through hole, and the conductive pillar extends to the first via holes and is integrally connected with the first lead and the third lead; the second lead and the fourth lead are respectively provided with a second via hole corresponding to the through hole, and the conductive column extends to the second via hole and is integrally connected with the second lead and the fourth lead.

Further, the first induction line and the second induction line are covered with a high-resistance carbon oil layer.

Further, the first lead, the second lead, the third lead and the fourth lead are covered with a conductive carbon oil layer.

Further, a cutting seam is formed on the first base material.

Furthermore, the second circuit layer comprises a second substrate and an induction film formed on the second substrate, the induction film is circular, the first induction line and the second induction line are both semicircular, and the induction film, the first induction line and the second induction line are opposite to each other and are arranged opposite to each other.

Furthermore, the induction film comprises a conductive silver paste layer formed on the second substrate and a high-resistance carbon oil layer covered on the conductive silver paste layer

Furthermore, a gasket is arranged on one side, back to the first circuit layer, of the second substrate.

Furthermore, the size of the second substrate is smaller than that of the first substrate, the first sensing line and the second sensing line are shielded by the second substrate, and the first lead and the second lead are exposed out of the second substrate.

Further, the isolation layer is arranged between the sensing area of the first substrate and the second substrate, round holes and openings communicated with the round holes and the outside are formed in the isolation layer corresponding to the sensing film, the first sensing lines and the second sensing lines are shielded by the isolation layer, and the first lead wires and the second lead wires are exposed out of the isolation layer.

Compared with the prior art, the utility model discloses flexible pressure sensor sets up the lead wire in the positive and negative both sides on first circuit layer, sets up the lead wire of leading electrical pillar connection both sides simultaneously for diversified with external circuit's connected mode, so can be suitable for the external device of isostructure, guarantee the convenience of being connected with external circuit and the stability of being connected the back circuit, it is convenient the utility model discloses flexible pressure sensor's installation is used.

Drawings

Fig. 1 is a schematic structural diagram of an embodiment of the flexible pressure sensor of the present invention.

Fig. 2 is a front view of a first wiring layer of the flexible pressure sensor of fig. 1.

Fig. 3 is a cross-sectional view taken along line III-III of fig. 2.

Fig. 4 is a back view of the first circuit layer shown in fig. 2.

Fig. 5 is an exploded view of the first wiring layer shown in fig. 2.

Fig. 6 is a schematic structural diagram of a second circuit layer of the flexible pressure sensor shown in fig. 1.

Fig. 7 is a front view of the second circuit layer shown in fig. 6.

Fig. 8 is a back view of the second circuit layer shown in fig. 6.

Fig. 9 is an exploded view of the second wiring layer shown in fig. 6.

Fig. 10 is a schematic structural view of an isolation layer of the flexible pressure sensor shown in fig. 1.

Detailed Description

In order to facilitate understanding of the present invention, the present invention will be described more fully hereinafter with reference to the accompanying drawings. One or more embodiments of the present invention are illustrated in the accompanying drawings to provide a more accurate and thorough understanding of the disclosed embodiments. It should be understood, however, that the present invention may be embodied in many different forms and is not limited to the embodiments described below.

Fig. 1 shows a specific embodiment of the flexible pressure sensor of the present invention, wherein the flexible pressure sensor is a multilayer thin sheet structure, and includes a first circuit layer 10, a second circuit layer 30, and an isolation layer 20 disposed between the first circuit layer 10 and the second circuit layer 30.

Referring to fig. 2 to 5, the first circuit layer 10 includes a first substrate 12, a front circuit 14 and a back circuit 16 respectively formed on two opposite sides of the first substrate 12, and a conductive pillar 18 electrically connecting the front circuit 14 and the back circuit 16. The first base material 12 is a rectangular thin sheet structure, preferably a thin film flexible material such as PET, PI, FR4 with excellent adhesion, and has good resilience, can be deformed to a certain extent when being pressed, and can be quickly restored to be deformed when not being pressed. The front traces 14 and the back traces 16 are preferably conductive silver paste formed on the first substrate 12 by printing, etching, electroplating, spraying, and the like. Preferably, a dicing line 120 is formed in the center of the first base substrate 12, and the dicing line 120 extends in the width direction of the first base substrate 12, and the number of the dicing lines 120 may be single or multiple, so that the first base substrate 12 can be bent conveniently, and the front surface line 14 or the back surface line 16 can be connected with an external circuit conveniently.

The front-side wiring 14 is formed on the front side of the first substrate 12, i.e., the side facing the second wiring layer 30. As shown in fig. 5, the front line 14 includes a first conductive line 140 and a second conductive line 142 spaced apart from each other. The first conductive line 140 has a first sensing line 144 and a first lead 145 formed at both ends thereof, and the second conductive line 142 has a second sensing line 146 and a second lead 147 formed at both ends thereof. In the illustrated embodiment, the first sensing line 144 and the second sensing line 146 are substantially semi-circular structures, and are disposed opposite to each other and spaced apart from each other by a certain distance, and the first sensing line 144 and the second sensing line 146 are spaced apart from each side of the first base substrate 12 by a certain width, so as to facilitate the disposition of the isolation layer 20. The first sensing line 144 and the second sensing line 146 are used as sensing lines and interact with the second circuit layer 30; the first lead 145 and the second lead 147 are disposed in parallel and spaced apart to serve as output terminals connected to an external circuit.

The back side of the first substrate 12, i.e. the side facing away from the second circuit layer 30, forms the back side circuit 16. The back side circuit 16 includes a third lead 160 and a fourth lead 162 arranged in parallel and spaced apart, and the third and fourth leads 160, 162 also serve as output terminals for connection to an external circuit. Preferably, the third lead 160 is opposite to the first lead 145 in position, and the third lead is electrically connected to the first lead 145 through the conductive pillar 18; the fourth lead 162 is located opposite the second lead 147 and is also electrically connected thereto by the conductive post 18. In the illustrated embodiment, a plurality of the conductive posts 18, specifically 3 conductive posts, are respectively connected between the first lead 145 and the third lead 160, and between the second lead 147 and the fourth lead 162. It should be understood that the conductive posts 18 are disposed to electrically connect the leads 145, 147, 160, 162 on two sides of the first base material 12, and the number is not limited to the illustrated embodiment.

The first base material 12 forms a through hole 122 corresponding to each conductive pillar 18; the first lead 145 and the third lead 160 respectively form a first via hole 148 and a first via hole 164 corresponding to each conductive pillar 18 therebetween; the second lead 147 and the fourth lead 162 respectively form a second via hole 149, 168 corresponding to each second conductive pillar 18 therebetween. The conductive pillar 18 is formed on the wall surface of the first substrate 12 surrounding the through hole 122 by a copper deposition process, a printing process, a coating process, etc. and extends to the periphery of the first via hole 148, 164 corresponding to the first and third leads 145, 160 or the periphery of the second via hole 149, 168 corresponding to the second and fourth leads 147, 162, so as to integrally connect and electrically connect the first and third leads 145, 160 or the second and fourth leads 147, 162.

One end (the left end in fig. 5) of the first sensing line 144 and the second sensing line 146 is disposed as a sensing region, and one end (the right end in fig. 5) of the first, second, third and fourth leads 145, 147, 160 and 162 is disposed as a wiring region. The first, second, third, and fourth leads 145, 147, 160, 162 are linear and extend to the right edge of the first base substrate 12 for easy connection to an external circuit. Preferably, the first sensing line 144 and the second sensing line 146 are respectively covered with a high resistance carbon oil layer 40, and the high resistance carbon oil layer 40 is used as a pressure sensitive layer, and has the functions of sensitivity to pressure reaction, wear resistance, oxidation resistance and the like, so as to ensure the conductivity of the sensing lines 144 and 146. The first, second, third and fourth lead wires 145, 147, 160 and 162 are respectively covered with a conductive carbon oil layer 42, and the conductive carbon oil layer 42 is used as a protective layer and has the functions of wear resistance, oxidation resistance and the like, so that the conductivity of the lead wires 145, 147, 160 and 162 is ensured.

The first, second, third and fourth leads 145, 147, 160 and 162 serve as the sensing circuit of the flexible pressure sensor of the present invention, that is, the output end of the first and second sensing wires 144 and 146 connected to the external circuit, when connected to the external circuit, there are multiple connection modes, for example, the first and second leads 145 and 147 are connected to the external circuit through the front side, or the third and fourth leads 160 and 162 are connected to the external circuit through the back side, or the first and fourth leads 145 and 162 are connected to the external circuit through the front side, or the second and third leads 147 and 160 are connected to the external circuit through the front side, and the stability and reliability of the connection between the flexible pressure sensor and the external circuit are ensured through the multiple connection paths. Because the first sensing line 144 and the second sensing line 146 are arranged at intervals, the sensing lines are in an open circuit state initially, and the output resistance between the first lead 145/the third lead 160 and the second lead 147/the fourth lead 162 is large.

As shown in fig. 6 to 9, the second circuit layer 30 is stacked on the sensing region of the first circuit layer 10, and includes a second substrate 32, a conductive silver paste layer 34 formed on the second substrate 32, and a high resistance carbon oil layer 36 formed on the conductive silver paste layer 34. The second substrate 32 is preferably a thin film flexible material with good adhesion, such as PET, PI, FR4, and the conductive silver paste layer 34 is formed on the front surface of the second substrate 32 by printing, coating, and the like, i.e. the side of the second substrate 32 facing the first circuit layer 10, and preferably faces the first sensing line 144 and the second sensing line 146. The high resistance carbon oil layer 36 covers the high resistance carbon oil layer 36, and the two layers together form the sensing film of the second circuit layer 30. The high resistance carbon oil layer 36 is used as a pressure sensitive layer, has the functions of sensitivity to pressure reaction, wear resistance, oxidation resistance and the like, ensures the conductivity of the sensing film, and can conduct the first sensing line 144 and the second sensing line 146 when the sensing film is in contact with the sensing line.

In this embodiment, the size of the second substrate 32 is much smaller than that of the first substrate 12, the second substrate 32 is located above the first and second sensing lines 144 and 146, and the first and second leads 145 and 147 are exposed outside the second substrate 32. In the illustrated embodiment, the conductive silver paste layer 34 has a circular shape and a size corresponding to the overall size of the first and second sensing lines 144 and 146. Preferably, a gasket 38 is disposed on the outer side of the second circuit layer 30, i.e. the side of the second substrate 32 facing away from the first circuit layer 10, for balancing the acting force of the flexible pressure sensor of the present invention.

As shown in fig. 10, the isolation layer 20 is disposed between the second substrate 32 of the second circuit layer 30 and the first substrate 12 of the first circuit layer 10, and is preferably an insulating double-sided tape, such as a pressure-sensitive double-sided tape, a heat-sensitive double-sided tape, or the like. The isolation layer 20 serves as an adhesive between the second substrate 32 and the first substrate 12, and isolates the sensing film (including the conductive silver paste layer 34 and the high resistance carbon oil layer 36 covering the conductive silver paste layer 34) of the second circuit layer 30 from the sensing circuit (including the first and second sensing lines 144, 146 and the high resistance carbon oil layer 40 covering the first and second sensing lines 144, 146) of the first circuit layer 10. A circular hole 22 is formed in the center of the isolation layer 20, and the position and size of the circular hole 22 correspond to those of the sensing film or the sensing line, so that a deformation space is formed between the sensing line and the sensing film while the sensing line and the sensing film are isolated. Preferably, the isolation layer 20 is further formed with an opening 24, and the opening 24 communicates the circular hole 22 with the external environment, so that the deformation space is always consistent with the external environment air pressure. In this embodiment, the size of the isolation layer 20 is equivalent to that of the second substrate 32, the isolation layer 20 surrounds and shields the first and second sensing lines 144, 146, and the first and second leads 145, 147 are exposed outside the isolation layer 20.

The utility model discloses flexible pressure sensor's the response circuit of the positive circuit 14 of first circuit layer 10 and the response membrane of second circuit layer 30 constitute response structure. Initially, the sensing circuit is separated from the sensing film by a small distance under the action of the isolation layer 20, and the whole circuit is broken. The utility model discloses flexible pressure sensor pressurized if exert pressure in during the gasket, response membrane pressurized produces to warp and response circuit and forms the contact, and the electrical property switches on response circuit's first response line 144 and second response line 146, changes the output resistance between first lead wire 145/third lead wire 160 and second lead wire 147/fourth lead wire 162 so. The utility model discloses flexible pressure sensor pressurized is big more, and the response membrane warp big more, and the area of contact of response circuit is big more, and output resistance between first lead wire 145/third lead wire 160 and second lead wire 147/fourth lead wire 162 is little so, obtains the corresponding relation of pressure and resistance in view of the above.

The utility model discloses flexible pressure sensor forms lead wire 145, 147, 160, 162 respectively in the both sides of first circuit layer 10, sets up simultaneously and leads lead wire 145, 147, 160, 162 that electrical pillar 18 connects both sides, and the lead wire of product positive and negative all can regard as the output, convenient and external device's being connected. In addition, the addition of the dicing lines 120 on the first substrate 12 makes the first circuit layer 10 easily bent and deformed, so that the product has better selection of the output surface. Still additionally, second circuit layer 30 increases gasket 38, can directly effectual transmission induction area again when making pressure evenly distributed, the utility model discloses flexible pressure sensor can be more sensitive, more accurate. In addition, the leads 145, 147, 160, 162 are covered with a wear-resistant and oxidation-resistant layer of conductive carbon oil 42 to ensure the effectiveness of the connection of each lead 145, 147, 160, 162 to an external circuit.

It should be noted that the present invention is not limited to the above embodiments, and other changes can be made by those skilled in the art according to the spirit of the present invention, and all the changes made according to the spirit of the present invention should be included in the scope of the present invention.

Claims (10)

1. The utility model provides a flexible pressure sensor, includes first circuit layer, second circuit layer and set up in isolation layer between first circuit layer and the second circuit layer, its characterized in that: the first circuit layer comprises a first substrate, a front circuit and a back circuit, wherein the front circuit and the back circuit are respectively formed on two opposite side surfaces of the first substrate, an induction area and a wiring area are respectively formed at two ends of the first substrate, the front circuit comprises a first induction line and a second induction line which are positioned in the induction area, and a first lead and a second lead which are positioned in the wiring area, the first lead is electrically connected with the first induction line, and the second lead is electrically connected with the second induction line; the back surface circuit comprises a third lead and a fourth lead which are positioned in the wiring area, the third lead is electrically connected with the first lead, and the fourth lead is electrically connected with the second lead; the second circuit is arranged on the induction area in a stacked mode and faces the first induction line and the second induction line.

2. The flexible pressure sensor according to claim 1, wherein the first substrate has a through hole formed therein, a conductive pillar is formed in the through hole, the first lead and the third lead respectively have a first via hole corresponding to the through hole, and the conductive pillar extends to the first via hole and integrally connects the first lead and the third lead; the second lead and the fourth lead are respectively provided with a second via hole corresponding to the through hole, and the conductive column extends to the second via hole and is integrally connected with the second lead and the fourth lead.

3. The flexible pressure sensor of claim 1, wherein the first and second sensing wires are covered with a layer of high resistance carbon oil.

4. The flexible pressure sensor of claim 1, wherein the first, second, third and fourth leads are covered with a layer of conductive carbon oil.

5. The flexible pressure sensor of any of claims 1-4, wherein the first substrate has a cut seam formed thereon.

6. The flexible pressure sensor of claim 1, wherein the second circuit layer comprises a second substrate and a sensing film formed on the second substrate, the sensing film is circular, the first and second sensing lines are semicircular, and the sensing film and the first and second sensing lines are opposite to each other and are disposed opposite to each other.

7. The flexible pressure sensor of claim 6, wherein the sensing film comprises a conductive silver paste layer formed on the second substrate and a high resistance carbon oil layer covering the conductive silver paste layer.

8. The flexible pressure sensor of claim 6, wherein a side of the second substrate facing away from the first wiring layer is provided with a spacer.

9. The flexible pressure sensor of claim 6, wherein the second substrate has a size smaller than the first substrate, the first and second sensing lines are shielded by the second substrate, and the first and second leads are exposed outside the second substrate.

10. The flexible pressure sensor according to claim 9, wherein the isolation layer is disposed between the sensing region of the first substrate and the second substrate, the isolation layer is formed with a circular hole and an opening communicating the circular hole with the outside corresponding to the sensing film, the first sensing line and the second sensing line are shielded by the isolation layer, and the first lead and the second lead are exposed outside the isolation layer.

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