TW201828007A - Sonic Touch Device and Electronic Device Having Same - Google Patents

Abstract

The present disclosure relates to a sonic fingerprint identification device including a substrate, an ultrasonic sensing unit formed on a surface of the substrate, and a signal transmission unit. The substrate has a circuit. The ultrasonic sensing unit includes a first electrode formed on the side of the circuit where away from the cover glass, a piezoelectric polymer layer, and a second electrode. The signal transmission unit is electrically connected to the substrate and the second electrode to transmit signals. The formation of the second electrode materials contained in the pore diameter less than 10um. The present disclosure also provides electronic device having this sonic fingerprint identification device.

Description

Acoustic touch device and electronic device using the same

The invention relates to a touch device, in particular to a sonic fingerprint recognition device and an electronic device using the sonic fingerprint recognition device.

With the widespread use of portable electronic devices, users have put forward more functional requirements for portable electronic devices. The fingerprint identification device is provided in a portable electronic device because of its privacy protection function, so as to increase the user experience. Fingerprint recognition devices can be classified into optical, capacitive, and sonic. The sonic fingerprint recognition device is widely used because its operation is not easily affected by the ambient temperature and humidity, and its long life and high resolution.

The conventional ultrasonic fingerprint recognition element can recognize the fingerprint of a finger placed on the fingerprint recognition element. When the user places his finger on the surface of the fingerprint identification element, the fingerprint of the user will be recognized, and the identity of the user will be verified. However, the signal of the sound wave will attenuate after passing through each of the dielectric layers, and the difference in the flatness and compactness of the dielectric layer will cause the unevenness of the sound wave transmission, which will eventually lead to uneven signal imaging and reduced discrimination.

In view of this, the present invention provides a sonic fingerprint recognition device, which has a relatively uniform sonic wave transmission speed and makes the discrimination result more accurate.

In addition, an electronic device using the sonic touch device is also provided.

An acoustic wave fingerprint identification device includes a cover plate, a circuit substrate, an ultrasonic sensing unit, and a signal transmission unit. The cover is fixed on one side of the circuit substrate. The ultrasonic sensing unit and the signal transmission unit are placed on one side of the circuit substrate away from the cover. The signal transmission unit is connected to the ultrasonic sensing unit and the circuit substrate at the same time. The cover plate covers one side of the first adhesive layer, and the other side of the adhesive layer away from the cover plate is in contact with the circuit substrate. The circuit substrate includes a first surface and a second surface, and an effective identification area. The projection area of the effective identification area on the cover is an area where the sonic fingerprint identification device of the present invention can effectively identify a fingerprint.

Compared with the conventional technology, the second electrode of the sonic fingerprint recognition device of the present invention is directly electrically connected to the flexible circuit board, and the flexible circuit board is also electrically connected to the circuit substrate at the same time, so the flexible circuit board can be directly used as the second electrode. And the first electrode electrical signal to simplify the structure of the sonic fingerprint recognition device. Further, the second electrode is made of a dense conductive material, and the inner pore diameter of the dense conductive material is less than 10 micrometers, so that the ultrasonic wave can have a more uniform transmission speed, and finally the identification result is more accurate.

In order to make the technical content disclosed in this application more detailed and complete, reference may be made to the drawings and the following specific embodiments of the present invention. The same reference numerals in the drawings represent the same or similar components. However, those skilled in the art should understand that the embodiments provided below are not intended to limit the scope covered by the present invention. In addition, the drawings are for illustrative purposes only, and are not drawn to their original dimensions.

An acoustic wave fingerprint recognition device of the present invention includes a cover plate, a circuit substrate, an ultrasonic sensing unit, and a signal transmission unit. The signal transmission unit is connected to the circuit substrate and the ultrasonic sensing unit at the same time. The ultrasonic sensing unit transmits and receives sound waves. By simplifying the structure of the sonic fingerprint identification device and rationally planning the position of the directional acoustic impedance material and the dense material in the structure, the sonic wave velocity can have a more uniform transmission speed, and finally the sensing result is more accurate.

Hereinafter, specific embodiments of the present invention will be described in further detail with reference to the accompanying drawings.

Example one

As shown in FIG. 1, the sonic fingerprint identification device 100 according to the first embodiment of the present invention includes a cover plate 111, a circuit substrate 130, an ultrasonic sensing unit 150, and a signal transmission unit 170. The circuit substrate 130 is fixed on one side of the cover plate 111. The supersonic sensing unit 150 and the signal transmission unit 170 are placed on one side of the circuit substrate 130 away from the cover plate 111. One end of the signal transmission unit 170 is connected to a control device (not shown) The other end is connected to the ultrasonic sensing unit 150 and the circuit substrate 130 at the same time to realize signal transmission.

The cover plate 111 and the circuit substrate 130 are bonded by the first adhesive layer 113.

The circuit substrate 130 includes a first surface 131 and a second surface 133 opposite to the first surface 131. The first surface 131 is in contact with the first adhesive layer 113. The circuit substrate 130 defines an effective identification area 135, and a projection area of the effective identification area 135 on the cover plate 111 is an area where the sonic fingerprint identification device 100 can effectively identify a fingerprint. The circuit substrate 130 includes a circuit for coupling the ultrasonic sensing unit 150 to generate a coupled electrical signal when the ultrasonic sensing unit 150 receives ultrasonic waves. In this embodiment, the circuit substrate 130 is a thin film transistor (TFT) array substrate. The TFT array substrate includes an array of pixel circuits, and the circuit is the pixel circuit array. Each pixel circuit includes at least one pixel electrode.

The ultrasonic sensing unit 150 includes a first electrode 153, a piezoelectric polymer layer 151, a second electrode 157, and a third adhesive layer 155. The first electrode 153 is disposed on a surface of the circuit substrate 130 away from the cover plate 111 corresponding to the effective identification area 135. The piezoelectric polymer layer 151 completely covers the first electrode 153; the third adhesive layer 155 covers at least a part of the surface of the piezoelectric polymer layer 151 away from the circuit substrate 130, and the second electrode 157 completely covers the third adhesive layer 155. In this embodiment, the first electrode 153 is at least one pixel electrode in the TFT array substrate.

The signal transmission unit 170 includes a flexible circuit board 171, a connection layer 173, a second adhesive layer 175, and a driving unit electrical connection pad 177. The driving unit electrical connection pad 177 is disposed on the second surface 133 of the circuit substrate 130. The adhesive layer 175 covers the driving unit electrical connection pad 177, and the connection layer 173 is connected to the second electrode 157. The connection layer 173 is formed on the flexible circuit board 171, and the connection layer 173 includes a plurality of gold fingers (not shown). Some of the gold fingers are electrically connected to the flexible circuit board 171, and some of the gold fingers are connected by the second adhesive layer. 175 is electrically connected to the drive unit electrical connection pad 177. The second electrode 157 is also connected to the flexible circuit board 171 by a gold finger (not shown) other than the connection layer 173.

An ink layer can be coated on the cover plate 111 for shielding or decoration. The first adhesive layer 113 is placed between the circuit substrate 130 and the cover plate 111 so that the two are firmly combined. The first adhesive layer 113 has a directional acoustic impedance in a certain direction, so that the sound wave passes through the first adhesive layer 113 at a wave velocity. More stable.

The material of the first electrode 153 may be indium tin oxide (ITO). The effective identification area 135 is stored in a plurality of pixel electrodes (not shown). The driving unit electrical connection pad 177 is made of conductive material. The second adhesive layer 175 is a conductive adhesive. The second electrode 157 is made of a dense conductive material. The pore diameter of the dense conductive material is less than 10 micrometers. The pore refers to pores determined by the nature of the material or unavoidably formed during the preparation of the material, not intentional processing Out. The material of the second electrode 157 may be copper, or a multilayer composite metal layer such as a copper layer and a nickel layer, a platinum layer and a gold layer, a chromium layer and a copper layer, and a chromium copper layer and a gold layer.

When manufacturing the sonic fingerprint recognition device 100, a piezoelectric polymer layer 151 may be first coated on a first electrode 153 on a circuit substrate 130, and a second electrode 157 and a connection layer 173 may be formed on the flexible circuit board 171. Then, the flexible circuit board 171 on which the second electrode 157 is formed is adhered to the surface of the piezoelectric polymer layer 151 through the third adhesive layer 155, so that the second electrode 157 is polymerized with piezoelectricity through the third adhesive layer 155. The physical layer 151 is combined.

A working cycle of the sonic fingerprint identification device 100 includes two parts: a transmitting phase and a receiving phase. In the transmitting phase, the flexible circuit board 171 simultaneously gives different voltage signals to the first electrode 153 and the second electrode 157, so that a potential difference is formed on both sides of the piezoelectric polymer layer 151, and mechanical vibration is generated to emit an ultrasonic wave. In the receiving stage, the flexible circuit board 171 applies a working voltage to the first electrode 153 and the second electrode 157 to maintain the normal operation of the piezoelectric polymer layer 151. The piezoelectric polymer layer 151 receives the reflected ultrasonic waves and generates induced charges. The electrode 153 is coupled to the piezoelectric polymer layer 151, and the coupling current is collected and analyzed by the circuit substrate 130, and then transmitted to the control device through the flexible circuit board 171.

The second electrode 157 of the above-mentioned sonic fingerprint identification device 100 is directly and electrically connected to the flexible circuit board 171 through the connection layer 173 and the gold finger. The flexible circuit board 171 is also electrically connected to the circuit substrate 130 at the same time, so the flexible circuit board 171 can The signals of the second electrode 157 and the first electrode 153 are directly used to simplify the structure of the sonic fingerprint recognition device 100. Further, the second electrode 157 is made of a dense conductive material, and the inner pore diameter of the dense conductive material is less than 10 micrometers, so that the ultrasonic wave can have a more uniform transmission speed, and finally the identification result is more accurate.

Example two

As shown in FIG. 2, the sonic fingerprint identification device 200 according to the second embodiment of the present invention includes a cover plate 211, a circuit substrate 230, an ultrasonic sensing unit 250, and a signal transmission unit 270.

The circuit substrate 230 is fixed on one side of the cover plate 211. The ultrasonic sensing unit 250 and the signal transmission unit 270 are placed on one side of the circuit substrate 230 away from the cover plate 211. One end of the signal transmission unit 270 is connected to a control device (not shown). The other end is connected to the ultrasonic sensing unit 250 and the circuit substrate 230 at the same time to realize signal transmission.

The cover plate 211 covers one side of the first adhesive layer 213, and the other side of the first adhesive layer 213 away from the cover plate 211 is in contact with the circuit substrate 230.

The circuit substrate 230 includes a first surface 231 and a second surface 233 opposite to the first surface 231. The first surface 231 is in contact with the first adhesive layer 213. The circuit substrate 230 defines an effective identification area 235, and a projection area of the effective identification area 235 on the cover plate 211 is an area where the acoustic fingerprint recognition device 200 can effectively identify a fingerprint. The circuit substrate 230 includes a circuit for coupling the ultrasonic sensing unit 250 to generate a coupled electrical signal when the ultrasonic sensing unit 250 receives an ultrasonic wave. In this embodiment, the circuit substrate 230 is a thin film transistor (TFT) array substrate. The TFT array substrate includes an array of pixel circuits, and the circuit is the pixel circuit array. Each pixel circuit includes at least one pixel electrode.

The ultrasonic sensing unit 250 includes a piezoelectric polymer layer 251, a first electrode 253, and a second electrode 257. The first electrode 253 is disposed on a surface of the circuit substrate 230 away from the cover plate 211 corresponding to the effective identification area 235. The piezoelectric polymer The layer 251 completely covers the effective identification area 235; the second electrode 257 covers at least part of the surface of the piezoelectric polymer layer 251 away from the circuit substrate 230.

The signal transmission unit 270 includes a flexible circuit board 271, a connection layer 273, a second adhesive layer 275, and a driving unit electrical connection pad 277. The driving unit electrical connection pad 277 is disposed on the second surface 233 of the circuit substrate 230. The adhesive layer 275 covers the driving unit electrical connection pad 277, the connection layer 273 is connected to the second electrode 257, and the flexible circuit board 271 covers the second electrode 257. The connection layer 273 is formed on the flexible circuit board 271, and the connection layer 273 includes a plurality of gold fingers (not shown). Some of the gold fingers are electrically connected to the flexible circuit board 271, and some of the gold fingers are connected by the second adhesive layer. 275 is electrically connected to the drive unit electrical connection pad 277. The second electrode 257 is also connected to the flexible circuit board 271 by a gold finger (not shown) other than the connection layer 273.

The cover layer 211 can be coated with an ink layer for shielding or decoration. The first adhesive layer 213 is placed between the circuit substrate 230 and the cover plate 211 so that the two are firmly combined. The first adhesive layer 213 has a directional acoustic impedance in a certain direction, so that the sound wave passes through the first adhesive layer 213 at a wave velocity. More stable.

The material of the first electrode 253 may be indium tin oxide (ITO). The memory of the effective identification area 235 is on a plurality of pixel electrodes (not shown). The driving unit electrical connection pad 277 is made of conductive material. The second adhesive layer 275 is a conductive adhesive. The second electrode 257 is made of a dense conductive material, and the pore diameter of the dense conductive material is less than 10 micrometers. The pore refers to pores determined by the nature of the material or inevitably formed during the preparation of the material, rather than intentional processing. Out. The material of the second electrode 257 is a composite material, and the surface of the material is sticky.

When making the sonic fingerprint recognition device 200, a piezoelectric polymer layer 251 may be first coated on a first electrode 253 on a circuit substrate 230, and a second electrode 257 and a connection layer 273 may be formed on the flexible circuit board 271. Then, the second electrode 257 is adhered to the surface of the piezoelectric polymer layer 251.

A working cycle of the sonic fingerprint recognition device 200 includes two parts: a transmitting phase and a receiving phase. In the transmitting phase, the flexible circuit board 271 simultaneously gives different voltage signals to the first electrode 253 and the second electrode 257, so that a potential difference is formed on both sides of the piezoelectric polymer layer 251, and mechanical vibration is generated to emit an ultrasonic wave. In the receiving stage, the flexible circuit board 271 applies a working voltage to the first electrode 253 and the second electrode 257 to maintain the normal operation of the piezoelectric polymer layer 251. The piezoelectric polymer layer 251 receives reflected ultrasonic waves and generates induced charges. The electrode 253 is coupled with the piezoelectric polymer layer 251, and the coupling current is collected and analyzed by the circuit substrate 230, and then transmitted to the control device through the flexible circuit board 271.

The second electrode 257 of the above-mentioned sonic fingerprint recognition device 200 is directly and electrically connected to the flexible circuit board 271 through the connection layer 273 and the gold finger. The flexible circuit board 271 is also electrically connected to the circuit substrate 230 at the same time, so the flexible circuit board 271 can The electrical signals of the second electrode 257 and the first electrode 253 are directly used to simplify the structure of the sonic fingerprint recognition device 200. Further, the second electrode 257 is made of a dense conductive material, and the inner pore diameter of the dense conductive material is less than 10 micrometers, so that the ultrasonic wave can have a more uniform transmission speed, and finally the identification result is more accurate.

Example three

As shown in FIG. 3, the sonic fingerprint recognition device 30 according to the third embodiment of the present invention includes a cover plate 311, a circuit substrate 330, an ultrasonic sensing unit 350, and a signal transmission unit 370.

The circuit substrate 330 is fixed on one side of the cover plate 311. The supersonic sensing unit 350 and the signal transmission unit 370 are placed on one side of the circuit substrate 330 away from the cover plate 311. One end of the signal transmission unit 370 is connected to a control device (not shown). The other end is connected to the ultrasonic sensing unit 350 and the circuit substrate 330 at the same time to realize signal transmission.

The cover plate 311 covers one side of the first adhesive layer 313, and the other side of the first adhesive layer 313 away from the cover plate 311 is in contact with the circuit substrate 330.

The circuit substrate 330 includes a first surface 331 and a second surface 333 opposite to the first surface 131. The first surface 331 is in contact with the first adhesive layer 313. The circuit substrate 330 defines an effective identification area 335, and a projection area of the effective identification area 335 on the cover plate 311 is an area where the sonic fingerprint identification device 300 can effectively identify a fingerprint. The circuit substrate 330 includes a circuit for coupling the ultrasonic sensing unit 350 to generate a coupled electrical signal when the ultrasonic sensing unit 350 receives an ultrasonic wave. In this embodiment, the circuit substrate 330 is a thin film transistor (TFT) array substrate. The TFT array substrate includes an array of pixel circuits, and the circuit is the pixel circuit array. Each pixel circuit includes at least one pixel electrode.

The ultrasonic sensing unit 350 includes a piezoelectric polymer layer 351, a first electrode 353, a second electrode 357, and a third adhesive layer 355. The first electrode 353 is disposed on the circuit substrate 330 away from the cover plate 311 corresponding to the effective identification area 335. The surface. The third adhesive layer 355 completely covers the effective identification area 335; the piezoelectric polymer layer 351 covers at least part of the surface of the third adhesive layer 355 away from the circuit substrate 330, and the second electrode 357 completely covers the piezoelectric polymer layer 351.

The signal transmission unit 370 includes a flexible circuit board 371, a connection layer 373, a second adhesive layer 375, and a driving unit electrical connection pad 377. The driving unit electrical connection pad 377 is disposed on the second surface 333 of the circuit substrate 330. The adhesive layer 375 covers the driving unit electrical connection pad 377, and the connection layer 373 is connected to the second electrode 357. The connection layer 373 is formed on the flexible circuit board 371, and the connection layer 373 includes a plurality of gold fingers (not shown). Some of the gold fingers are electrically connected to the flexible circuit board 371, and some of the gold fingers are connected by the second adhesive layer. 375 is electrically connected to the drive unit electrical connection pad 377. The second electrode 357 is also connected to the flexible circuit board 371 by a gold finger (not shown) other than the connection layer 373.

The cover layer 311 can be coated with an ink layer for shielding or decoration. The first adhesive layer 313 is placed between the circuit substrate 330 and the cover plate 311 so as to firmly bond the two. The first adhesive layer 313 has a directional acoustic impedance in a certain direction, so that the sound wave passes through the first adhesive layer 313 at a wave velocity. More stable.

The material of the first electrode 353 may be indium tin oxide (ITO). The memory of the effective recognition area 335 is on a plurality of pixel electrodes (not shown). The driving unit electrical connection pad 377 is made of conductive material. The second adhesive layer 375 is a conductive adhesive. The second electrode 357 is made of a dense conductive material, and the pore diameter in the dense conductive material is less than 10 micrometers. The pore refers to pores determined by the nature of the material or unavoidably formed during the preparation of the material, not intentional processing. Out. The material of the second electrode 357 may be copper or a multilayer composite metal layer such as a copper layer and a nickel layer, a platinum layer and a gold layer, a chromium layer and a copper layer, and a chrome copper layer and a gold layer.

When the sonic fingerprint recognition device 300 is manufactured, the second electrode 357 and the connection layer 373 are formed on the flexible circuit board 371, the piezoelectric polymer layer 351 is coated on the second electrode 357, and the piezoelectric polymer is formed. The second electrode 357 of the layer 351 is bonded to the surface of the first electrode 353 on the circuit substrate 330 through the third adhesive layer 355, so that the first electrode 353 is connected to the piezoelectric polymer layer 351 through the third adhesive layer 355 Combined.

A working cycle of the sonic fingerprint identification device 300 includes two parts: a transmitting phase and a receiving phase. In the transmitting phase, the flexible circuit board 371 simultaneously gives different voltage signals to the first electrode 353 and the second electrode 357, so that a potential difference is formed on both sides of the piezoelectric polymer layer 351, and mechanical vibration is generated to emit an ultrasonic wave. In the receiving stage, the flexible circuit board 371 only applies a working voltage to the first electrode 353 or the second electrode 357 to maintain the normal operation of the piezoelectric polymer layer 351. The piezoelectric polymer layer 351 receives the reflected ultrasonic waves and generates induced charges. An electrode 353 is coupled to the piezoelectric polymer layer 351, and the coupling current is collected and analyzed by the circuit substrate, and then transmitted to the control device through the flexible circuit board 371.

The second electrode 357 of the above-mentioned sonic fingerprint recognition device 300 is directly and electrically connected to the flexible circuit board 371 through the connection layer 373 and the gold finger. The flexible circuit board 371 is also electrically connected to the circuit substrate 330 at the same time. Therefore, the flexible circuit board 371 can The signals of the second electrode 357 and the first electrode 353 are directly used to simplify the structure of the sonic fingerprint recognition device 300. Further, the second electrode 357 is made of a dense conductive material, and the inner pore diameter of the dense conductive material is less than 10 micrometers, so that the ultrasonic wave can have a more uniform transmission speed, and finally the identification result is more accurate.

Embodiment 4

As shown in FIG. 4, the sonic fingerprint identification device 400 according to the first embodiment of the present invention includes a cover plate 411, a circuit substrate 430, an ultrasonic sensing unit 450, and a signal transmission unit 470.

The circuit substrate 430 is fixed on one side of the cover plate 411, and the ultrasonic sensing unit 450 and the signal transmission unit 470 are placed on one side of the circuit substrate 430 away from the cover plate 411. One end of the signal transmission unit 470 is connected to a control device (not shown) The other end is connected to the ultrasonic sensing unit 450 and the circuit substrate 430 at the same time.

The cover plate 411 covers one side of the first adhesive layer 413, and the other side of the first adhesive layer 413 away from the cover plate 411 is in contact with the circuit substrate 430.

The circuit substrate 430 includes a first surface 431 and a second surface 433 opposite to the first surface 131. The first surface 431 is in contact with the first adhesive layer 413. The circuit substrate 430 also defines an effective identification area 435, and a projection area of the effective identification area 335 on the cover plate 311 is an area where the acoustic fingerprint recognition device 400 can effectively identify a fingerprint. The circuit substrate 430 contains a circuit for coupling the ultrasonic sensing unit 450 to generate a coupled electrical signal when the ultrasonic sensing unit 450 receives an ultrasonic wave. In this embodiment, the circuit substrate 430 is a thin film transistor (TFT) array substrate. The TFT array substrate includes an array of pixel circuits, and the circuit is the pixel circuit array. Each pixel circuit includes at least one pixel electrode.

The ultrasonic sensing unit 450 includes a piezoelectric polymer layer 451, a third adhesive layer 455, a first electrode 453, and a second electrode 457. The first electrode 353 is disposed on a surface of the circuit substrate 430 away from the cover plate 411 corresponding to the effective identification area 335. The piezoelectric polymer layer 451 completely covers the effective identification area 435; the third adhesive layer 455 covers at least a part of the surface of the piezoelectric polymer layer 451 away from the circuit substrate 430, and the second electrode 457 completely covers the third adhesive layer 455. In this embodiment, the first electrode 453 is at least one pixel electrode in the TFT array substrate.

The signal transmission unit 470 includes a flexible circuit board 471, a connection layer 473, a second adhesive layer 475, and a driving unit electrical connection pad 477. The connection layer 473 includes a first metal connection pad 4731 and a second metal connection pad 4733. The driving unit is electrically connected. The pad 477 is disposed on the second surface 433 of the circuit substrate 430. The second adhesive layer 475 covers the driving unit electrical connection pad 477. The second metal connection pad 4733 is placed on the end of the second electrode 457 near the end of the signal transmission unit 470. unit. The connection layer 473 is formed on the flexible circuit board 471, and the connection layer 473 includes a plurality of gold fingers (not shown). Some of the gold fingers are electrically connected to the flexible circuit board 471, and some of the gold fingers are connected by the second adhesive layer. 475 is electrically connected to the drive unit electrical connection pad 477.

The cover layer 411 can be coated with an ink layer for shielding or decoration. The first adhesive layer 413 is placed between the circuit substrate 430 and the cover plate 411 so that the two are firmly combined. The first adhesive layer 413 has a directional acoustic impedance in a certain direction, so that the sound wave passes through the first adhesive layer 413 at a wave velocity. More stable.

The material of the first electrode 453 may be indium tin oxide (ITO). The valid identification area 435 is stored in a plurality of pixel electrodes (not shown). The driving unit electrical connection pad 477 is made of conductive material. The second adhesive layer 475 is a conductive adhesive. The second electrode 457 is made of a dense conductive material. The pore diameter of the dense conductive material is less than 10 micrometers. The pore refers to pores determined by the nature of the material or unavoidably formed during the preparation of the material, not intentional processing. Out. The material of the second electrode 457 may be copper, or a multilayer composite metal layer such as a copper layer and a nickel layer, a platinum layer and a gold layer, a chromium layer and a copper layer, and a chromium copper layer and a gold layer.

When manufacturing the sonic fingerprint recognition device 400, a piezoelectric polymer layer 451 may be first coated on a first electrode 453 on a circuit substrate 430, a connection layer 473 may be formed on the flexible circuit board 471, and a second electrode 457 It is electrically connected to the second metal connection pad 4733, and then the second electrode 457 is bonded to the surface of the piezoelectric polymer layer 451 through the third adhesive layer 455, so that the second electrode 457 is connected with the third adhesive layer 455 and The piezoelectric polymer layer 451 is bonded.

A working cycle of the sonic fingerprint recognition device 400 includes two parts, a transmitting phase and a receiving phase. In the transmitting phase, the flexible circuit board 471 simultaneously gives different voltage signals to the first electrode 453 and the second electrode 457, so that a potential difference is formed on both sides of the piezoelectric polymer layer 451, and mechanical vibration is generated to emit an ultrasonic wave. In the receiving stage, the flexible circuit board 471 only applies a working voltage to the first electrode 453 or the second electrode 457 to maintain the normal operation of the piezoelectric polymer layer 451. The piezoelectric polymer layer 451 receives reflected ultrasonic waves and generates induced charges. The electrode 453 is coupled with the piezoelectric polymer layer 451, and the coupling current is collected and analyzed by the circuit substrate 430, and then transmitted to the control device through the flexible circuit board 471.

The second electrode 457 of the above-mentioned sonic fingerprint recognition device 400 is directly and electrically connected to the flexible circuit board 471 through the second metal connection pad 4733. The flexible circuit board 471 is also electrically connected to the circuit substrate 430 at the same time. Therefore, the flexible circuit board 471 can The signals of the second electrode 457 and the first electrode 453 are directly used to simplify the structure of the sonic fingerprint recognition device 400. Further, the second electrode 457 is made of a dense conductive material, and the inner pore diameter of the dense conductive material is less than 10 micrometers, so that the ultrasonic wave can have a more uniform transmission speed, and finally the identification result is more accurate.

Please refer to FIG. 5 and FIG. 6 together. The present invention further provides an electronic device 10, which includes a main body 12 and a sonic fingerprint recognition device 500 disposed in the main body 12. The sonic fingerprint recognition device 500 can be implemented as described above. Any of the sonic fingerprint recognition devices described in Examples 1 to 4. In FIG. 5, only the electronic device 10 is a mobile phone as an example. In other embodiments, the electronic device 10 may also be a personal computer, a smart home appliance, an industrial controller, or the like. When the electronic device 10 is a mobile phone, the sonic fingerprint recognition device 500 can be set corresponding to the home key of the mobile phone, so that the home key has a function of touch operation. The sonic fingerprint recognition device 500 in FIG. 5 only uses the structure of the sonic fingerprint recognition device in the first embodiment as an example. In other embodiments, the sonic fingerprint recognition device 500 may also be the second to fourth embodiments. Any of the sonic fingerprint recognition devices described above.

Hereinabove, specific embodiments of the present invention have been described with reference to the drawings. However, those skilled in the art can understand that, without departing from the spirit and scope of the present invention, various changes and substitutions can be made to the specific embodiments of the present invention. These changes and substitutions fall within the scope defined by the claims of the present invention.

100, 200, 300, 400, 500 ‧‧‧ sonic fingerprint recognition devices

130, 230, 330, 430‧‧‧ circuit boards

150, 250, 350, 450‧‧‧ Ultrasonic sensing units

170, 270, 370, 470‧‧‧ signal transmission units

111, 211, 311, 411‧‧‧ cover

113, 213, 313, 413‧‧‧ first adhesive layer

131, 231, 331, 431‧‧‧ first surface

133, 233, 333, 433‧‧‧Second surface

135, 235, 335, 435‧‧‧ effective identification area

171, 271, 371, 471‧‧‧ flexible circuit board

173, 273, 373, 473‧‧‧ connecting layers

4731‧‧‧First metal connection pad

4733‧‧‧Second metal connection pad

175, 275, 375, 475‧‧‧Second adhesive layer

177, 277, 377, 477‧‧‧ drive unit electrical connection pad

151, 251, 351, 451‧‧‧ Piezoelectric polymer layers

153, 253, 353, 453‧‧‧ First electrode

155, 355, 455‧‧‧ Third adhesive layer

157, 257, 357, 457‧‧‧Second electrode

10‧‧‧ electronic device

12‧‧‧ main body

FIG. 1 is a schematic cross-sectional view of a sonic fingerprint recognition device according to a first embodiment of the present invention.

FIG. 2 is a schematic cross-sectional view of a sonic fingerprint recognition device according to a second embodiment of the present invention.

3 is a schematic cross-sectional view of a sonic fingerprint recognition device according to a third embodiment of the present invention.

4 is a schematic cross-sectional view of a sonic fingerprint recognition device according to a fourth embodiment of the present invention.

FIG. 5 is a schematic diagram of an electronic device to which a sonic fingerprint recognition device of the present invention is applied.

FIG. 6 is a schematic cross-sectional view taken along VI-VI in FIG. 5.

no

Claims (11)

An acoustic wave fingerprint recognition device includes a circuit substrate, an ultrasonic sensing unit formed on the surface of the circuit substrate, and a signal transmission unit. The circuit substrate contains a circuit. The improvement is that the ultrasonic sensing unit includes a layer stacked on the circuit. A circuit board away from the first electrode on the side of the cover, a piezoelectric polymer layer, and a second electrode; the signal transmission unit is electrically connected to the circuit and the second electrode to realize signal transmission, and a material forming the second electrode The pores contained therein have a pore diameter of less than 10um. The sonic fingerprint identification device according to claim 1, wherein the second electrode material is copper. The sonic fingerprint identification device according to claim 1, wherein the second electrode material is a multilayer composite metal layer. The sonic fingerprint identification device according to claim 3, wherein the multilayer composite metal layer is a multilayer composite metal layer formed of a copper layer and a nickel layer, a platinum layer and a gold layer, a chromium layer and a copper layer, and a chromium copper layer and a gold layer. . The sonic fingerprint identification device according to claim 1, wherein the circuit substrate is a TFT array substrate, and the TFT array substrate includes an array of pixel circuits, and the circuit is the pixel circuit array; The pixel circuit includes a pixel electrode, and the first electrode is one of the pixel electrodes. The sonic fingerprint identification device according to claim 1, wherein the signal transmission unit includes a flexible circuit board, and the flexible circuit board is electrically connected to the circuit substrate and the second electrode. The sonic fingerprint identification device according to claim 6, wherein the piezoelectric polymer layer is formed on a first electrode, the second electrode is formed on the flexible electrode plate, and the second electrode is formed by an adhesive The layer is bonded to one side of the piezoelectric polymer layer away from the circuit substrate. The sonic fingerprint identification device according to claim 6, wherein the piezoelectric polymer layer is formed on the second electrode, and the piezoelectric polymer layer is away from one side of the second electrode through an adhesive layer and the first electrode. One electrode is combined. The sonic fingerprint identification device according to claim 6, wherein the piezoelectric polymer layer is formed on the first electrode, and the piezoelectric polymer layer is away from one side of the first electrode through the third adhesive layer and the first electrode. The two electrodes are stuck. The sonic fingerprint identification device according to claim 9, wherein a material of the second electrode is a metal, and an oxidation protection layer is formed on a surface of the second electrode far from the piezoelectric polymer layer. An electronic device includes a main body and a sonic fingerprint identification device provided in the main body, wherein the sonic fingerprint identification device is the sonic fingerprint identification device according to any one of claims 1-10.