Ultrasonic wave biological identification device and electronic equipment
Technical field
The present invention relates to touch display field, in particular to a kind of ultrasonic wave biological identification device and electronic equipment.
Background technique
Ultrasonic fingerprint identification technology can be scanned fingerprint by ultrasonic wave, with traditional fingerprint recognition mode phase
Than the identification of, ultrasonic fingerprint fingerprint can be carried out deeper into analysis, even if finger surface speckles with dirt and does not also hinder ultrasonic wave
Sampling, or even the unique 3D feature of fingerprint is identified under the surface that can also penetrate to the skin.Even if there is the feelings such as water, sweat on hand
Under condition, still can accurately it identify.However, there are the unsharp problems of image for current ultrasonic wave identification device.
Summary of the invention
Based on this, it is necessary to which the relatively clear ultrasonic wave biological identification device of image can be obtained by providing one kind.
In addition, also providing a kind of electronic equipment.
A kind of ultrasonic wave biological identification device, comprising:
Thin film transistor (TFT), with a thickness of 195 microns~295 microns, and the thickness of the thinnest part of the thin film transistor (TFT) with most
Thickness difference at thickness is no more than 40 microns;
Piezoelectric layer is layered on the thin film transistor (TFT), and the thinnest part of the piezoelectric layer is differed with the thickness in thickness
No more than 2 microns;
Conductive layer is layered on the thin film transistor (TFT), and the thinnest part of the conductive layer is differed with the thickness in thickness
No more than 6 microns;And
Acoustic matching layer is layered on the conductive layer on the conductive layer, the acoustic matching layer with a thickness of 20 microns~
80 microns, and the thinnest part of the acoustic matching layer differs with the thickness in thickness and is no more than 10 microns.
Although ultrasonic wave has the ability for capableing of penetrable material, ultrasonic wave can occur instead when penetrating unlike material
It penetrates, and ultrasonic wave biological identification device is usually all multilayered structure, every layer of acoustic impedance is generally all different, the conduction to ultrasonic wave
The damping capacity of speed and ultrasonic signal is inconsistent, and above-mentioned ultrasonic wave biological identification device is thin by the way that piezoelectric layer to be layered in
It is on film transistor, conductive layer is folded over the piezoelectric layer, acoustic matching layer be laminated on the electrically conductive, with realize ultrasonic wave transmitting and
The reception for the ultrasonic wave being reflected back, then by cooperation control piezoelectric layer with a thickness of 8 microns~10 microns, and control piezoelectric layer
Thinnest part is differed with the thickness in thickness is no more than 2 microns, so that the signal strength for the ultrasonic wave that piezoelectric layer is launched is as far as possible
Unanimously, meanwhile, by the thickness control of thin film transistor (TFT) be 195 microns~295 microns, the thickness of the thinnest part of thin film transistor (TFT) with
The thickness difference in thickness is no more than 40 microns, and the thickness control for controlling conductive layer is 13 microns~19 microns, and controls conduction
The thinnest part of layer differ with the thickness in thickness no more than 6 microns, control acoustic matching layer with a thickness of 20 microns~80 microns, and
The thinnest part of control acoustic matching layer differ with the thickness in thickness no more than 10 microns, with guarantee thin film transistor (TFT), conductive layer and
Acoustic matching layer is respectively in corresponding thickness range, and each layer has respective uniformity respectively, makes ultrasonic wave in each layer
Path difference it is consistent as much as possible so that the ultrasonic wave reflected through each layer can form resonance as much as possible, reduce each layer not
Interfering with each other between the ultrasonic wave of resonance can be formed, so that the signal for the ultrasonic wave being reflected back for receiving piezoelectric layer to the greatest extent may be used
Can be consistent, so that the image that ultrasonic wave biological identification device obtains is relatively clear.
It in one of the embodiments, further include cover board, the cover board and the acoustic matching layer are far from the conductive layer
Side stacking, and the cover board covers side of the acoustic matching layer far from the conductive layer;The thickness of the thin film transistor (TFT)
Degree be 195 microns~235 microns, the cover board with a thickness of 500 microns~800 microns;Alternatively, the thickness of the thin film transistor (TFT)
Degree be 255 microns~295 microns, the cover board with a thickness of 350 microns~500 microns.It is each that setting cover board can play protection
The effect of layer is conducive to the service life for increasing ultrasonic wave biological identification device;According to the thin film transistor (TFT) of above-mentioned different-thickness
The cover board of respective thickness is selected, so that the ultrasonic wave of the reflection of cover board can be with the ultrasonic waveform of the reflection of other each layers at altogether
Vibration so that the ultrasonic wave that the ultrasonic wave of cover board reflection can be reflected with other each layers as much as possible resonates, and reduces cover board
It is interfered with each other between the ultrasonic wave of reflection and the ultrasonic wave of other each layer reflections, to guarantee that image is clear as much as possible.
It in one of the embodiments, further include the ink for being layered in the cover board on the side of the acoustic matching layer
Layer, the color of the ink layer are white, the acoustic matching layer with a thickness of 20 microns~55 microns.Using the ink of white
Layer, and control acoustic matching layer with a thickness of 20 microns~55 microns, be more advantageous to make to be laminated with white ink layer cover board it is anti-
The ultrasonic wave penetrated resonates with acoustic matching layer as much as possible.
It in one of the embodiments, further include the ink for being layered in the cover board on the side of the acoustic matching layer
Layer, the color of the ink layer are black, the acoustic matching layer with a thickness of 45 microns~80 microns.Using the ink of black
Layer, and control acoustic matching layer with a thickness of 45 microns~80 microns, be more advantageous to make to be laminated with the ink layer of black cover board it is anti-
The ultrasonic wave penetrated resonates with acoustic matching layer as much as possible.
In one of the embodiments, the acoustic matching layer with a thickness of 45 microns~55 microns.Control acoustic matching layer
With a thickness of 45 microns~55 microns, not only contribute to reduce the cover board for the ink layer for being laminated with black and surpassing for acoustic matching layer reflection
Interfering with each other between sound wave is also beneficial to reduce the cover plate assembly for the ink layer for being laminated with white and surpassing for acoustic matching layer reflection
Interference between sound wave, with preferably make acoustic matching layer and be formed with ink layer cover board reflection ultrasonic waveform at resonance.
It in one of the embodiments, further include the adhesive layer between the acoustic matching layer and the conductive layer, institute
State that adhesive layer is fixed to bond the acoustic matching layer and the conductive layer, the adhesive layer with a thickness of 10 microns~20 microns, and
The thinnest part of the adhesive layer is differed with the thickness in thickness is no more than 10 microns.It by acoustic matching layer and is led by using adhesive layer
Electric layer is fixed together, and production is simpler, and by control adhesive layer with a thickness of 10 microns~20 microns, and control bonding
The thinnest part of layer is differed with the thickness in thickness is no more than 10 microns, i.e., while controlling the thickness of adhesive layer, control bonding
The thickness of layer has certain uniformity, so that the ultrasonic wave of adhesive layer reflection can be super with other each layer reflections as much as possible
Sound wave forms resonance.
The material of the conductive layer is silver in one of the embodiments,.Silver has good electric conductivity, and control is
The ultrasonic wave of the reflection of above-mentioned thickness, the conductive layer that material is silver can preferably be formed altogether with the ultrasonic wave of other each layer reflections
Vibration.
The material of the piezoelectric layer is the copolymer of Kynoar and trifluoro-ethylene in one of the embodiments,.It should
The piezoelectric layer of material, which is equipped with above-mentioned thickness, can make piezoelectric layer have preferable piezoelectric property, be conducive to improve piezoelectric layer transmitting
The signal strength of ultrasonic wave.
The conductive layer includes plate-like body and side wall in one of the embodiments, the plate-like body and the pressure
Electric layer stacking, the plate-like body with a thickness of 13 microns~19 microns, and the thinnest part of the plate-like body and thickness
Thickness difference is no more than 6 microns, and the side wall ring is arranged one week around the edge of the plate-like body, to form an accommodating cavity, institute
It states side of the side wall far from the plate-like body to be fixedly connected with the thin film transistor (TFT), so that the conductive layer and the film
Transistor cooperates the receiving piezoelectric layer jointly, wherein the acoustic matching layer is layered in the plate-like body far from the piezoelectricity
On the side of layer.By the way that conductive layer is arranged to above structure, is conducive to piezoelectric layer and launches the consistent ultrasonic wave of signal strength,
Further improve the clarity of image.
Step is formed on the outer surface of side of the side wall far from the plate-like body in one of the embodiments,
Portion, the ultrasonic wave biological identification device further includes circuit board, and the circuit board is brilliant with the stage portion and the film respectively
Body Guan Bangding.The bonding of circuit board and conductive layer can be facilitated by the way that stage portion is arranged.
It in one of the embodiments, further include cover board and the bonding between the acoustic matching layer and the conductive layer
Layer, the cover board and the acoustic matching layer are laminated far from the side of the conductive layer, the stage portion and the thin film transistor (TFT)
Bonding is at one section of the same side of the circuit board, side of the circuit board far from the thin film transistor (TFT) and the cover board interval
Distance.By making side of the circuit board far from thin film transistor (TFT) be spaced a distance with cover board, to avoid circuit board and cover board phase
It abuts, and cover board inclination is caused to cause the thickness of adhesive layer unintelligible, and keep the path difference of adhesive layer inconsistent, signal strength is not
Clarity that is consistent and influencing image.
A kind of electronic equipment, including above-mentioned ultrasonic wave biological identification device.Due to above-mentioned ultrasonic wave biological identification device
Be imaged it is relatively clear so that the imaging of above-mentioned electronic equipment also relatively clear degree.
Detailed description of the invention
Fig. 1 is the sectional view of the ultrasonic wave biological identification device of an embodiment;
Fig. 2 is the sectional view of the thin film transistor (TFT) of ultrasonic wave biological identification device shown in FIG. 1, piezoelectric layer and conductive layer;
Fig. 3 is the sectional view of the ultrasonic wave biological identification device of another embodiment;
Fig. 4 is the sectional view of the ultrasonic wave biological identification device of another embodiment;
Fig. 5 is the sectional view of the ultrasonic wave biological identification device of another embodiment.
Specific embodiment
To facilitate the understanding of the present invention, a more comprehensive description of the invention is given in the following sections with reference to the relevant attached drawings.In attached drawing
Give preferred embodiment of the invention.But the invention can be realized in many different forms, however it is not limited to herein
Described embodiment.On the contrary, purpose of providing these embodiments is keeps the understanding to the disclosure more saturating
It is thorough comprehensive.
Unless otherwise defined, all technical and scientific terms used herein and belong to technical field of the invention
The normally understood meaning of technical staff is identical.Term as used herein in the specification of the present invention is intended merely to description tool
The purpose of the embodiment of body, it is not intended that in the limitation present invention.
As shown in Figure 1, electronic equipment of an embodiment, such as mobile phone, computer etc., including ultrasonic wave biological identification device
100, which for example can be used for the identification of fingerprint.Wherein, the ultrasonic wave biological identification device
100 include cover board 110, ink layer 120, thin film transistor (TFT) 130, piezoelectric layer 140, conductive layer 150, acoustic matching layer 160, adhesive layer
170 and circuit board 180.
Cover board 110 can be inlayed in the housing of the electronics device, can also be laminated with the shell of electronic equipment.Cover board 110
For Transparent Parts.Cover board 110 is selected from one of transparency glass plate, quartz plate, alumina plate and transparent organic board, these materials
Cover board 110 not only there is more appropriate mechanical strength, and industrial design (ID, Industrial can also be met
Design requirement).
Ink layer 120 is layered on a surface of cover board 110.Ink layer 120 can be formed by modes such as silk-screen printings
On cover board 110.Specifically, ink layer 120 is black ink layer or white ink layer.Wherein, the material of ink layer 120 is ring
Oxygen resinae ink, the ink layer of the material differ larger with the acoustic resistance of air, influence caused by the propagation of ultrasonic wave smaller.
Specifically, ink layer 120 with a thickness of 8 microns~32 microns.
By setting Transparent Parts for cover board 110, and ink layer 120 is set on cover board 110, cover board 110 can be made to have
There is required color, and cover board 110 is made to have the function of blocking extraneous light.
The circuit that can convert the electrical signal to picture signal is provided on thin film transistor (TFT) 130.Wherein, thin film transistor (TFT)
130 with a thickness of 195 microns~295 microns, and the thickness of the thinnest part of thin film transistor (TFT) 130 differs not with the thickness in thickness
More than 40 microns.The thin film transistor (TFT) 130 controlled with a thickness of 195 microns~295 microns with other each layer thickness matchings
While, the thickness for meeting the thinnest part of thin film transistor (TFT) 130 is differed with the thickness in thickness no more than 40 microns thin to guarantee
The thickness uniformity of film transistor 130.Even if the thickness of thin film transistor (TFT) 130 in 195 microns~295 microns, controls film
The thickness of the thinnest part of transistor 130 differs fewer with the thickness in thickness, and the thickness of thin film transistor (TFT) 130 is more uniform, warp
The signal strength for the ultrasonic wave that thin film transistor (TFT) 130 reflects is more consistent.
Further, thin film transistor (TFT) 130 with a thickness of 195 microns~235 microns, cover board 110 with a thickness of 500 microns
~800 microns;Alternatively, thin film transistor (TFT) 130 with a thickness of 255 microns~295 microns, cover board 110 with a thickness of 350 microns~
500 microns.The cover board 110 of respective thickness is selected according to the thin film transistor (TFT) 130 of above-mentioned different thickness, so that cover board 110 is anti-
The ultrasonic wave penetrated can be with the ultrasonic waveforms of other each layers reflections at resonance, so that the ultrasonic wave that reflects of cover board 110 can to the greatest extent can
Energy ground and the ultrasonic wave of other each layer reflections resonate, and reduce what the ultrasonic wave that cover board 110 reflects was reflected with other each layers
It is interfered between ultrasonic wave, to guarantee that image is clear as much as possible.
Piezoelectric layer 140 is laminated on thin film transistor (TFT) 130.Piezoelectric layer 140 can emit what ultrasonic wave was reflected back with reception
Ultrasonic wave, and the ultrasonic wave that will reflect back into is converted into electric signal.Wherein, piezoelectric layer 140 with a thickness of 8 microns~10 microns,
And the thinnest part of piezoelectric layer 140 differs with the thickness in thickness and is no more than 2 microns.By the thickness control of piezoelectric layer 140 above-mentioned
While range, the thinnest part of control piezoelectric layer 140 is differed with the thickness in thickness is no more than 2 microns, can make piezoelectric layer 140
With more appropriate piezoelectric constant D33, and the signal strength of ultrasonic wave that piezoelectric layer 140 is launched is also more consistent, and presses
The thinnest part of electric layer 140 differs smaller with the thickness in thickness, and the thickness of piezoelectric layer 140 is more uniform, and piezoelectric layer 140 emits super
The signal strength of sound wave is more consistent.
Specifically, the material of piezoelectric layer 140 is P (VDF-TrFE) (copolymer of Kynoar and trifluoro-ethylene), should
The piezoelectric layer 140 of material, which is equipped with above-mentioned thickness, can make piezoelectric layer 140 have preferable piezoelectric property, be conducive to improve piezoelectric layer
The signal strength of the ultrasonic wave of 140 transmittings.Wherein, in P (VDF-TrFE), the molar ratio of Kynoar and poly- trifluoro-ethylene is
60:40,70:30,80:20 or 90:10.
It should be noted that the material of piezoelectric layer 140 is not limited to above-mentioned material, for example, the material of piezoelectric layer 140 may be used also
Think the homopolymer of polyvinylidene chloride (PVDC), the copolymer of polyvinylidene chloride, polytetrafluoroethylene (PTFE) homopolymer, gather inclined two
Copolymer, diisopropylamine bromide (DTPAB) or Kynoar of vinyl chloride etc..
Conductive layer 150 is layered on piezoelectric layer 140.Wherein, conductive layer 150 with a thickness of 13 microns~19 microns, and lead
The thinnest part of electric layer 150 is differed with the thickness in thickness is no more than 6 microns.By control conductive layer 150 with a thickness of above-mentioned thickness
Degree, and makes the thickness of conductive layer 150 meet certain uniformity so that the signal strength for the ultrasonic wave that conductive layer 150 reflects compared with
Be it is consistent, be conducive to improve image clarity.I.e. while control conductive layer 150 is with a thickness of 13 microns~19 microns,
The thinnest part of conductive layer 150 differs smaller with the thickness in thickness, and the thickness of conductive layer 150 is more uniform, what conductive layer 150 reflected
The signal strength of ultrasonic wave is more consistent.
Referring to Figure 2 together, further, conductive layer 150 includes plate-like body 152 and side wall 154, plate-like body 152
It is laminated with piezoelectric layer 140, side wall 154 is arranged one week around the edge of plate-like body 152, and to form an accommodating cavity, side wall 154 is remote
Side from plate-like body 152 is fixedly connected with thin film transistor (TFT) 130, so that conductive layer 150 and thin film transistor (TFT) 130 are matched jointly
Close receiving piezoelectric layer 140.Launch signal strength one by the way that the setting layer above structure of conductive layer 150 is conducive to piezoelectric layer 140
The ultrasonic wave of cause further improves the clarity of imaging.At this point, plate-like body 152 with a thickness of 13 microns~19 microns, and plate
The thinnest part of shape ontology 152 is differed with the thickness in thickness is no more than 6 microns.
Further, the material of conductive layer 150 is silver.Silver has electric conductivity well, and controlling is above-mentioned thickness, material
Material can preferably form resonance with the ultrasonic wave of other each layer reflections for the ultrasonic wave that the conductive layer 150 of silver reflects.Specifically,
Conductive layer 150 can be directly by coating silver paste, and then sintering is prepared.
It it should be noted that the material of conductive layer 150 is not limited to silver, such as can also be ITO.
Acoustic matching layer 160 is layered on conductive layer 150.Wherein, side of the acoustic matching layer 160 far from conductive layer 150 is inspection
Survey region.Specifically, acoustic matching layer 160 is layered on side of the plate-like body 152 far from piezoelectric layer 140, and cover board 110 is close to oil
The side of layer of ink 120 and acoustic matching layer 160 are laminated far from the side of conductive layer 150.Cover board 110 and ink layer 120 can play
The effect of protection and shading, the interference to avoid extraneous light to ultrasonic wave biological identification device 100.
Specifically, the material of acoustic matching layer 160 is that chip attaches film (Die attach film, DAF).Acoustic matching layer 160
It can be directly formed on ink layer 120 by techniques such as coating, silk-screen printing, sprayings.
Acoustic matching layer 160 with a thickness of 20 microns~80 microns, and the thickness of the thinnest part of acoustic matching layer 160 and thickness
Difference is no more than 10 microns.The acoustic matching layer 160 of the thickness can be well matched with the piezoelectric layer 140 of above-mentioned thickness, so that
The ultrasonic wave that the ultrasonic wave that acoustic matching layer 160 reflects is reflected with piezoelectric layer 140 as much as possible resonates;And control acoustic matching layer
160 thinnest part is differed with the thickness in thickness is no more than 10 microns, to guarantee the uniformity of the thickness of acoustic matching layer 160, makes
Ultrasonic wave is consistent as much as possible in the path difference of acoustic matching layer 160.For example, acoustic matching layer 160 with a thickness of 50 microns, then,
The thickness in the thickness of acoustic matching layer 160 is no more than 55 microns, and the thickness of thinnest part is not less than 45 microns.It should be noted that
While control acoustic matching layer 160 is with a thickness of 20 microns~80 microns, the thinnest part of acoustic matching layer 160 and the thickness in thickness
Degree difference is smaller, and the signal strength for the ultrasonic wave that acoustic matching layer 160 reflects is more consistent.
Further, when the color of ink layer 120 be white, acoustic matching layer 160 with a thickness of 20 microns~55 microns.It adopts
With white ink layer 120, and control acoustic matching layer 160 with a thickness of 20 microns~55 microns, be more advantageous to make to be laminated with it is white
The ultrasonic wave that the cover board 110 of the ink layer 120 of color reflects resonates with acoustic matching layer 160 as much as possible.
When ink layer 120 color be black, acoustic matching layer 160 with a thickness of 45 microns~80 microns.Using black
Ink layer 120, and control acoustic matching layer 160 with a thickness of 45 microns~80 microns, be more advantageous to the ink for making to be laminated with black
The ultrasonic wave that the cover board 110 of layer 120 reflects resonates with acoustic matching layer 160 as much as possible.
Preferably, acoustic matching layer 160 with a thickness of 45 microns~55 microns.The thickness for controlling acoustic matching layer 160 is micro- 45
Change in rice~55 microns, not only contributes to the cover board 110 for reducing the ink layer 120 for being laminated with black and acoustic matching layer 160 is anti-
The interference between ultrasonic wave penetrated is also beneficial to reduce 110 component of cover board and acoustic matching layer of the ink layer 120 for being laminated with white
Interference between the ultrasonic wave of 160 reflections, preferably to make acoustic matching layer 160 and be formed with the cover board 110 of ink layer 120 to reflect
Ultrasonic waveform at resonance.
Adhesive layer 170 is located at acoustic matching layer 160 and conductive layer 150, and fixed bonding acoustic matching layer 160 and conductive layer 150,
Adhesive layer 170 with a thickness of 10 microns~20 microns, and the thinnest part of adhesive layer 170 differed with the thickness in thickness be no more than 10
Micron so that the ultrasonic wave that reflects of adhesive layer 170 can ultrasonic waveform as much as possible with other each layers reflections at resonance, and it is logical
It crosses and acoustic matching layer 160 and conductive layer 150 is fixed together using adhesive layer 170, make simpler.It should be noted that
While control adhesive layer 170 is with a thickness of 20 microns~80 microns, thinnest part differs smaller with the thickness in thickness, bonding
The signal strength of the ultrasonic wave of 170 reflection of layer is more consistent.
Specifically, the material of adhesive layer 170 is liquid glue, and liquid glue for example can be the NCA3285 of Henkel.
It is appreciated that acoustic matching layer 160 can not also be laminated by adhesive layer 170 and conductive layer 150, can also directly lead to
It crosses the techniques such as coating, silk-screen printing, spraying to be formed on conductive layer 150, at this point, adhesive layer 170 is arranged in 160 He of acoustic matching layer
Between ink layer 120, thus together with acoustic matching layer 160 is adhesively fixed with cover board 110.
Circuit board 180 is flexible circuit board.Circuit bonding on circuit board 180 and conductive layer 150, thin film transistor (TFT) 130
(bonding)。
In the illustrated embodiment, the side wall 154 of conductive layer 150 is far from shape on the outer surface of the side of plate-like body 152
At there is a stage portion 156, circuit board 180 respectively with 130 bonding of stage portion 156 and thin film transistor (TFT).By the way that 156 energy of stage portion is arranged
Enough facilitate the bonding of circuit board 180 and conductive layer 150.
Further, in the same side of circuit board 180, circuit board 180 is remote for stage portion 156 and 130 bonding of thin film transistor (TFT)
The side of scrapping off film transistor 130 is spaced a distance with cover board 110.By making circuit board 180 far from thin film transistor (TFT) 130
Side is spaced a distance with cover board 110, abuts against to avoid circuit board 180 and cover board 110, and the inclination of cover board 110 is caused to cause
Make the in uneven thickness of adhesive layer 170, and keep the path difference of adhesive layer 170 inconsistent, signal strength is inconsistent and influences imaging
Clarity.
It should be noted that can also there is no stage portion 156 on the side wall 154 of conductive layer 150, at this point, circuit board 180 is straight
Connect 154 bonding of side wall with conductive layer 150;Alternatively, conductive layer 150 is also not necessarily limited to as above structure, conductive layer 150 or
One plate structure;Ink layer 120 also can be omitted, at this point, cover board 110 is nontransparent material, and cover board 110 is directly and acoustic matching
Side stacking of the layer 160 far from conductive layer 150;Cover board 110 also can be omitted, at this point, acoustic matching layer 160 is directly and electronic equipment
Shell stacking, i.e., electronic equipment shell replace cover board 110.
Above-mentioned ultrasonic wave biological identification device 100 at least has the advantage that
(1) although ultrasonic wave has the ability for capableing of penetrable material, ultrasonic wave can occur when penetrating unlike material
Reflection, and ultrasonic wave biological identification device 100 is usually all multilayered structure, every layer of acoustic impedance is generally all different, to ultrasonic wave
Conduction of velocity and ultrasonic signal damping capacity it is inconsistent, and above-mentioned ultrasonic wave biological identification device 100 is by by piezoelectricity
Layer 140 is layered on thin film transistor (TFT) 130, conductive layer 150 is layered on piezoelectric layer 140, acoustic matching layer 160 is layered in conduction
On layer 150, with the reception for the ultrasonic wave realizing the transmitting of ultrasonic wave and being reflected back, then pass through the thickness of cooperation control piezoelectric layer 140
Degree is 8 microns~10 microns, and the thinnest part for controlling piezoelectric layer differs with the thickness in thickness and is no more than 2 microns, so that piezoelectricity
The signal strength for the ultrasonic wave that layer 140 is launched is as consistent as possible, meanwhile, it is 195 micro- by the thickness control of thin film transistor (TFT) 130
Rice~295 microns, the thickness of the thinnest part of thin film transistor (TFT) 130 is differed with the thickness in thickness is no more than 40 microns, and control is led
The thickness control of electric layer 150 is 13 microns~19 microns, and controls the thinnest part of conductive layer 150 and differ not with the thickness in thickness
More than 6 microns, control acoustic matching layer 160 with a thickness of 20 microns~80 microns, and control the thinnest part of acoustic matching layer 160 with most
Thickness difference at thickness is no more than 10 microns, to guarantee thin film transistor (TFT) 130, conductive layer 150 and acoustic matching layer 160 respectively right
In the thickness range answered, and each thickness degree has respective uniformity respectively, and ultrasonic wave is made to the greatest extent may be used in the path difference of each layer
Energy ground is consistent, so that the ultrasonic wave reflected through each layer can form resonance as much as possible, resonance cannot be formed by reducing each layer
Interfering with each other between the ultrasonic wave being reflected back, so that the signal for the ultrasonic wave being reflected back for receiving piezoelectric layer 140 to the greatest extent may be used
Can be consistent, so that the image that ultrasonic wave biological identification device 100 obtains is relatively clear.
(2) after due to 180 bonding of circuit board, height is higher than conductive layer 150, will lead to the inclination of cover board 110, causes to bond
It is approached while the adhesive layer 170 of cover board 110 and silver layer is after, it is in uneven thickness, cause adhesive layer 170 to the path difference of ultrasonic wave
It is inconsistent, and the acoustic matching layer 160 of above-mentioned thickness can not only make up the segment difference that conductive layer 150 is higher by after 180 bonding of circuit board,
To ensure that cover board 110 is higher by 180 a distance of circuit board, and enable adhesive layer 170 as much as possible uniformly, and acoustic matching layer
160 can also match the acoustic impedance of cover board 110 with the acoustic impedance of examined object.
In addition, since the image that above-mentioned ultrasonic wave biological identification device 100 obtains is relatively clear, so that using the ultrasonic wave
The image of the electronic equipment of biological identification device 100 is relatively clear.
As shown in Fig. 2, the ultrasonic wave biological identification device 200 of another embodiment and ultrasonic wave biological identification device 100
Structure it is roughly the same, difference is, the acoustic matching layer 210 of the ultrasonic wave biological identification device 200 of present embodiment is directly logical
It crosses the techniques such as coating, silk-screen printing to be formed on side of the conductive layer 220 far from piezoelectric layer 230, at this point it is possible to pass through adhesive layer
240 are bonded together ink layer 250 and acoustic matching layer 210.
Due to the structure and ultrasonic wave biological identification device 100 of the ultrasonic wave biological identification device 200 of present embodiment
Structure is roughly the same, and therefore, ultrasonic wave biological identification device 200 also has the similar effect of ultrasonic wave biological identification device 100.
As shown in figure 3, the ultrasonic wave biological identification device 300 of another embodiment and ultrasonic wave biological identification device 200
Structure it is roughly the same, difference is, does not have on the acoustic matching layer 310 of the ultrasonic wave biological identification device 300 of present embodiment
Cover board and ink layer are set, at this point, acoustic matching layer 310 can directly be laminated with the shell of electronic equipment.
Due to the structure and ultrasonic wave biological identification device 200 of the ultrasonic wave biological identification device 300 of present embodiment
Structure is roughly the same, and therefore, ultrasonic wave biological identification device 300 also has the similar effect of ultrasonic wave biological identification device 200.
As shown in figure 4, the ultrasonic wave biological identification device 400 of another embodiment and ultrasonic wave biological identification device 100
Structure it is roughly the same, difference is, the cover board 410 and acoustic matching layer of the ultrasonic wave biological identification device 400 of present embodiment
Ink layer is not provided between 420, cover board 410 can be transparent material for nontransparent material or cover board 410, at this point, cover board
410 are directly laminated with the shell of electronic equipment.
Due to the structure and ultrasonic wave biological identification device 100 of the ultrasonic wave biological identification device 400 of present embodiment
Structure is roughly the same, and therefore, ultrasonic wave biological identification device 400 also has the similar effect of ultrasonic wave biological identification device 100.
The following are specific embodiment part (below by taking ultrasonic wave biological identification device 100 as an example):
Embodiment 1
The thickness and material of each layer of the ultrasonic wave biological identification device of the present embodiment are as follows:
The material of cover board is glass plate, with a thickness of 800 microns;Ink layer is white, with a thickness of 20 microns;Thin film transistor (TFT)
With a thickness of 215 microns, and the thinnest part of thin film transistor (TFT) differs 20 microns with the thickness in thickness;The material of piezoelectric layer is poly-
The copolymer (molar ratio of Kynoar and trifluoro-ethylene is 60:40) of vinylidene and poly- trifluoro-ethylene, it is micro- with a thickness of 9
Rice, and the thinnest part of piezoelectric layer is differed with the thickness in thickness at 2 microns;The material of conductive layer is silver, the plate sheet of conductive layer
Body with a thickness of 16 microns, and thinnest part differs 6 microns with the thickness in thickness;The material of acoustic matching layer is that chip attaches film,
Acoustic matching layer with a thickness of 50 microns, and the thinnest part of acoustic matching layer differs 8 microns with the thickness in thickness;The material of adhesive layer
For NCA3285, with a thickness of 15 microns, the thinnest part of adhesive layer differs 10 microns with the thickness in thickness.
Embodiment 2
The thickness and material of each layer of the ultrasonic wave biological identification device of the present embodiment are as follows:
The material of cover board is glass plate, with a thickness of 550 microns;Ink layer is white, with a thickness of 20 microns;Thin film transistor (TFT)
With a thickness of 215 microns, and the thinnest part of thin film transistor (TFT) differs 40 microns with the thickness in thickness;The material of piezoelectric layer is poly-
The copolymer (molar ratio of Kynoar and trifluoro-ethylene is 60:40) of vinylidene and trifluoro-ethylene, with a thickness of 9 microns,
And the thinnest part of piezoelectric layer is differed with the thickness in thickness at 2 microns;The material of conductive layer is silver, the plate-like body of conductive layer
With a thickness of 16 microns, and thinnest part differs 6 microns with the thickness in thickness;The material of acoustic matching layer is that chip attaches film, sound
With layer with a thickness of 25 microns, and the thinnest part of acoustic matching layer differs 10 microns with the thickness in thickness;The material of adhesive layer is
NCA3285, with a thickness of 15 microns, and the thinnest part of adhesive layer differs 10 microns with the thickness in thickness.
Embodiment 3
The thickness and material of each layer of the ultrasonic wave biological identification device of the present embodiment are as follows:
The material of cover board is glass plate, with a thickness of 350 microns;Ink layer is white, with a thickness of 20 microns;Thin film transistor (TFT)
With a thickness of 275 microns, and the thinnest part of thin film transistor (TFT) differs 30 microns with the thickness in thickness;The material of piezoelectric layer is poly-
The copolymer (molar ratio of Kynoar and trifluoro-ethylene is 60:40) of vinylidene and trifluoro-ethylene, with a thickness of 9 microns,
And the thinnest part of piezoelectric layer is differed with the thickness in thickness at 1 micron;The material of conductive layer is silver, the plate-like body of conductive layer
With a thickness of 15 microns, thinnest part differs 4 microns with the thickness in thickness;The material of acoustic matching layer is that chip attaches film, acoustic matching
Layer with a thickness of 25 microns, and the thinnest part of acoustic matching layer differs 10 microns with the thickness in thickness;The material of adhesive layer is
NCA3285, with a thickness of 15 microns, and the thinnest part of acoustic matching layer differs 6 microns with the thickness in thickness.
Test to obtain the image of the ultrasonic wave biological identification device of the present embodiment using the identical test method of embodiment 1
Situation is shown in Table 1.
Embodiment 4
The thickness and material of each layer of the ultrasonic wave biological identification device of the present embodiment are as follows:
The material of cover board is glass plate, with a thickness of 800 microns;Ink layer is black, with a thickness of 20 microns;Thin film transistor (TFT)
With a thickness of 215 microns, and the thinnest part of thin film transistor (TFT) differs 40 microns with the thickness in thickness;The material of piezoelectric layer is poly-
The copolymer (molar ratio of Kynoar and trifluoro-ethylene is 60:40) of vinylidene and trifluoro-ethylene, with a thickness of 9 microns,
And the thinnest part of piezoelectric layer is differed with the thickness in thickness at 2 microns;The material of conductive layer is silver, the plate-like body of conductive layer
With a thickness of 16 microns, and thinnest part differs 6 microns with the thickness in thickness;The material of acoustic matching layer is that chip attaches film, sound
With layer with a thickness of 75 microns, and the thinnest part of acoustic matching layer differs 10 microns with the thickness in thickness;The material of adhesive layer is
NCA3285, with a thickness of 15 microns, and the thinnest part of adhesive layer differs 10 microns with the thickness in thickness.
Embodiment 5
The thickness and material of each layer of the ultrasonic wave biological identification device of the present embodiment are as follows:
The material of cover board is glass plate, with a thickness of 400 microns;Ink layer is black, with a thickness of 20 microns;Thin film transistor (TFT)
With a thickness of 275 microns, and the thinnest part of thin film transistor (TFT) differs 20 microns with the thickness in thickness;The material of piezoelectric layer is poly-
The copolymer (molar ratio of Kynoar and trifluoro-ethylene is 60:40) of vinylidene and trifluoro-ethylene, with a thickness of 9 microns,
And the thinnest part of piezoelectric layer is differed with the thickness in thickness at 2 microns;The material of conductive layer is silver, the plate-like body of conductive layer
With a thickness of 16 microns, and thinnest part differs 6 microns with the thickness in thickness;The material of acoustic matching layer is that chip attaches film, sound
With layer with a thickness of 50 microns, and the thinnest part of acoustic matching layer differs 10 microns with the thickness in thickness;The material of adhesive layer is
NCA3285, with a thickness of 15 microns, and the thinnest part of adhesive layer differs 10 microns with the thickness in thickness.
Embodiment 6
The thickness and material of each layer of the ultrasonic wave biological identification device of the present embodiment are as follows:
The material of cover board is glass plate, with a thickness of 400 microns;Ink layer is white, with a thickness of 20 microns;Thin film transistor (TFT)
With a thickness of 215 microns, and the thinnest part of thin film transistor (TFT) differs 20 microns with the thickness in thickness;The material of piezoelectric layer is poly-
The copolymer (molar ratio of Kynoar and trifluoro-ethylene is 60:40) of vinylidene and trifluoro-ethylene, with a thickness of 9 microns,
And the thinnest part of piezoelectric layer is differed with the thickness in thickness at 2 microns;The material of conductive layer is silver, the plate-like body of conductive layer
With a thickness of 16 microns, and thinnest part differs 6 microns with the thickness in thickness;The material of acoustic matching layer is that chip attaches film, sound
With layer with a thickness of 50 microns, and the thinnest part of acoustic matching layer differs 8 microns with the thickness in thickness;The material of adhesive layer is
NCA3285, with a thickness of 15 microns, the thinnest part of adhesive layer differs 10 microns with the thickness in thickness.
Embodiment 7
The thickness and material of each layer of the ultrasonic wave biological identification device of the present embodiment are as follows:
The material of cover board is glass plate, with a thickness of 800 microns;Ink layer is white, with a thickness of 20 microns;Thin film transistor (TFT)
With a thickness of 215 microns, and the thinnest part of thin film transistor (TFT) differs 20 microns with the thickness in thickness;The material of piezoelectric layer is poly-
The copolymer (molar ratio of Kynoar and trifluoro-ethylene is 60:40) of vinylidene and trifluoro-ethylene, with a thickness of 10 microns,
And the thinnest part of piezoelectric layer is differed with the thickness in thickness at 2 microns;The material of conductive layer is silver, the plate-like body of conductive layer
With a thickness of 16 microns, and thinnest part differs 6 microns with the thickness in thickness;The material of acoustic matching layer is that chip attaches film, sound
With layer with a thickness of 50 microns, and the thinnest part of acoustic matching layer differs 8 microns with the thickness in thickness;The material of adhesive layer is
NCA3285, with a thickness of 15 microns, the thinnest part of adhesive layer differs 10 microns with the thickness in thickness.
Embodiment 8
The thickness and material of each layer of the ultrasonic wave biological identification device of the present embodiment are as follows:
The material of cover board is glass plate, with a thickness of 800 microns;Ink layer is white, with a thickness of 20 microns;Thin film transistor (TFT)
With a thickness of 245 microns, and the thinnest part of thin film transistor (TFT) differs 20 microns with the thickness in thickness;The material of piezoelectric layer is poly-
The copolymer (molar ratio of Kynoar and trifluoro-ethylene is 60:40) of vinylidene and trifluoro-ethylene, with a thickness of 8 microns,
And the thinnest part of piezoelectric layer is differed with the thickness in thickness at 2 microns;The material of conductive layer is silver, the plate-like body of conductive layer
With a thickness of 20 microns, and thinnest part differs 6 microns with the thickness in thickness;The material of acoustic matching layer is that chip attaches film, sound
With layer with a thickness of 50 microns, and the thinnest part of acoustic matching layer differs 8 microns with the thickness in thickness;The material of adhesive layer is
NCA3285, with a thickness of 15 microns, the thinnest part of adhesive layer differs 20 microns with the thickness in thickness.
Test: the ultrasonic wave biological identification device of Examples 1 to 8 is subjected to fingerprint recognition, to observe whether it can obtain
The resolution ratio of the fingermark image formed to clearly fingermark image, the ultrasonic wave biological identification device of Examples 1 to 8 is shown in Table 1.
Table 1
From table 1 it follows that the resolution ratio of the fingermark image of the ultrasonic wave biological identification device of Examples 1 to 7 is
3.5 pixel per inch, and the high resolution of the fingermark image of the ultrasonic wave biological identification device of embodiment 1 is up to the every English of 4.0 pixels
It is very little, and the resolution ratio of the fingermark image of the ultrasonic wave biological identification device of embodiment 8 is only 3.0 pixel per inch, it is clear that implement
The fingermark image of the ultrasonic wave biological identification device of example 1~7 has higher resolution ratio, this illustrates the ultrasonic wave of Examples 1 to 7
The fingermark image of biological identification device has higher clarity.
Each technical characteristic of embodiment described above can be combined arbitrarily, for simplicity of description, not to above-mentioned reality
It applies all possible combination of each technical characteristic in example to be all described, as long as however, the combination of these technical characteristics is not deposited
In contradiction, all should be considered as described in this specification.
The embodiments described above only express several embodiments of the present invention, and the description thereof is more specific and detailed, but simultaneously
It cannot therefore be construed as limiting the scope of the patent.It should be pointed out that coming for those of ordinary skill in the art
It says, without departing from the inventive concept of the premise, various modifications and improvements can be made, these belong to protection of the invention
Range.Therefore, the scope of protection of the patent of the invention shall be subject to the appended claims.