One, piezoelectric effect reachs the material that suppress report

 

1, piezoelectric effect

 

The material that suppress report is to point to be pressed master piece to be used in its two end panel can appear a kind of big single crystal of charge or the solid material of many brilliant, it is the main carrier that undertakes energy changeover and signal are delivered. What report material has the character that suppress report the earliest is brother of French physicist Courier, their discovery put the heavy thing in quartz 1880 on crystal, certain surface can produce crystal charge, charge volume and pressure become direct ratio, become its piezoelectric effect. Piezoelectric effect can be divided for piezoelectric effect and go against piezoelectric effect two kinds. System of certain interpose cable allots unripe deformation in mechanical power effect, make upright inside electric system center of negative electric charge produces relative to displacement polarization, occurrence symbol of two upright surfaces ties as a result instead charge, its charge density and stress become scale. This kind of phenomenon that produces “ report ” by “ pressure ” is called piezoelectric effect. Conversely, if will have the electric field outside the park of interpose cable system of piezoelectric effect in, electric field makes medium in-house displacement of negative electric charge, bring about medium to produce deformation. This kind produces “ machinery to be out of shape the phenomenon of ” is called by “ report ” go against piezoelectric effect.

 

2, the material that suppress report

 

(1) the single crystal that suppress report

 

The single crystal that suppress report is to show by crystal space latticedot matrix grows the crystal that Cheng grows in order and becomes. Structure of this kind of crystal does not have symmetrical center, because this is had,press electric sex. Like quartz body is in charge of acerbity titanium of acerbity lithium of acerbity lithium of crystal, gallium, germanium, germanium and Tie Jing niobium acerbity lithium, tantalum acerbity lithium. The growth of material of the single crystal that suppress report the method includes hydro-thermal method, carry pull law, crucible to drop strange law of law and bubble.

 

(2) the pottery and porcelain that suppress report

 

The pottery and porcelain that suppress report criterion generally refer to presses electric polycrystal, it is to show the raw material that uses essential component undertakes mixture, shape, high temperature agglomeration, the polycrystal that obtains by the solid photograph reaction between powdery bead and agglomeration process imperceptible grain random assembles and becomes, the pottery and porcelain that has the sex that suppress report says to press electric pottery and porcelain. Material of the pottery and porcelain that suppress report is had good humidity, wear-resisting and high temperature resistant function, hardness is taller, physics and chemical performance are steady. Material of the pottery and porcelain that suppress report includes acid of titanium of BT of titanium acerbity barium, zirconium lead of acid of titanium of zirconium of plumbic PZT, modified, slant PT of lead of acid of titanium of PBLN of lithium of barium of acerbity lead of niobium acid lead, niobium, modified.

 

(3) the film that suppress report

 

Atom or nuclear group are passed or stuff of the film that suppress report splashs ejaculation method to deposit is on underlay and be formed, its structure can be Fei Jing voice, much brilliant is single crystal even. The parts of an apparatus of preparation of the film that suppress report does not need to use the single crystal suppressing report with high price, should go up in underlay only deposit a very weak data that suppress report, have economy and the characteristic that the province expects consequently. And preparation comes to deposit film according to certain orientaton in filmy process, do not need to undertake polarization directional wait for craft with cut. Additional, the range of application of parts of an apparatus that uses preparation of the film that suppress report is wide, make simple, cost cheap, efficiency of its energy changeover is tall at the same time, still as can compositive as semiconductor technology, accord with the parts of an apparatus that suppress report miniature is changed and compositive the tide that turn.

 

Press the main preparation method of electric film

 

The data of the film that suppress report with relatively at present extensive application basically has nitrogen to change aluminous AlN) , zinc oxide (the stuff of the film that suppress report of ZnO) and PZT series. Function expresses place to show as follows quite:

 

 

AlN is a kind of important III-V that has structure of fine zinc mine a group of things with common features nitride, its structure stability is tall. With ZnO and PZT the film that suppress report is compared, alN presses report filmily to answer inferior, but the acoustical velocity of wave that its advantage depends on AlN film is taller, it is OK that this makes AlN filmy the filter that uses GHz wait with high frequency resonator. In addition, film of AlN pressing report is a kind of very good high temperature material, when because the sex suppressing report of AlN material is in,temperature is 1200 ℃ as before good, so AlN presses electric film parts of an apparatus to be able to get used to high temperature environment, this film stuff still has very tall chemical stability, filmy below caustic work environment parts of an apparatus can work normally as before and insusceptible. AlN material still has good heat to conduct function, the quantity of heat that will produce in time in the meeting when parts of an apparatus works is conducted go out, because produce heat,won’t pass much and the service life that reduces parts of an apparatus. Because AlN is filmy,the advantage of many sided performance of material makes its received corresponding application. The resonator of body sound wave that is based on AlN to press electric film for example (FBAR) , its resonance frequency can amount to GHz, wide application received in communication domain.

 

ZnO and AlN have structure of fine zinc mine euqally. Axis of high quality tall C is preferred the ZnO of orientaton has the very good property that suppress report. Constant of ZnO crystal lattice and silicon underlay photograph are about the same, so crystal lattice matchs degree tall. Preparation is at present clean degree of high ZnO filmy technology already very mature. However, the drawback with very big ZnO depends on be being used at harsh environment hard, because its are bisexual oxide, fight cankerous ability so very weak, this affected the application that its issue in a few specific environments.

 

Zirconium titanium acerbity lead is the binary department solid solution that comprises by PbTiO3 and PbZrO3, its chemistry type is Pb (Zr1-xTix) O3, logogram is PZT. PbTiO3 and PbZrO3 all are construction of mine of ABO3 calcic titanium, so PZT also is construction of calcic titanium mine. In addition, still can add other microelement in PZT (wait like niobium, antimonial, stannum, manganese, tungsten) will improve performance.

 

PZT film is one of data suppressing report with most at present extensive application, the PZT material that is high-pressured report character had been been in by a large number of application loudhailer, in exceeding the electronic parts such as acoustic imaging probe, supersonic transducer, buzzer and supersonic electric machinery. The earliest people uses sol – gel legal system had PZT is filmy, undertake applied actually in MEMS parts of an apparatus, be like driver, transducer and pressure sensor. As filmy preparation technology rise, begin emerge in large numbers to give a variety of preparation measures, and also use a variety of technology preparation PZT presses electric film, if magnetism accuses,splash shoot technology of technology, pulse laser deposit (PLD) , deposit of chemical gas phase (CVD) wait with deposit technology of metallic compound gas phase. Film of PZT pressing report and blame are ferroelectric ZnO data phase is compared, the mainest good point is PZT material has ferroelectricity, below certain adscititious electric field and temperature condition, electricdomain of PZT material interior produces roll, initiative polarization way is new and certain, such making the action orientaton that the polarization axis that forms randomly originally in much brilliant material traverses electric field is arranged and arose to press report to answer completely. So the function suppressing report of PZT material wants material of prep above ZnO, it is the double above of ZnO. Learn in photoelectron, the domain such as system of cable of microelectronics, personal computer and compositive optics, PZT film has been applied extensively.

 

PZT filmy material has tall dielectric constant, low sound wave rate, tall coupling coefficient, the transverse coefficient that suppress report is in with the fore-and-aft coefficient that suppress report 3 person in highest, also be regarded as 3 person in the stuff of the film that suppress report that has an outlook most, but process of PZT filmy preparation is complex, as poorer as MEMS craft compatibility, preparation process must control the scale of each constituent strictly, the character that suppress report gets brilliant to, composition deserves to compare, the element influence such as granularity, the PZT film that repeats preparation high quality is put in greater difficulty. Be versed in at present industry most the data suppressing report that often uses still is the mainstream with AlN.

 

2, sensor of the MEMS that suppress report

 

1, ink jet of the MEMS that suppress report prints a head

 

Ink jet is printed print the solution that offerred agile, economy for individual documentation, still be at present in family and small-sized office environment a large number of application. In the meantime, the large wide cut of art application prints ink jet CAD and graph as sheet second print and the technical choice that small lot prints. MEMS technology brought the solution of “ inviting ” for it: Every ink jet prints a head to have higher nozzle density, and through large quantities of quantities production realizes acceptability production cost.

 

The head that print basically has plan of two kinds of technologies: Heat is epispastic print and press report to print. The most ink jet that suppress report prints an use PZT to press material of electric pottery and porcelain, use filmy and deposit PZT to press electric pottery and porcelain to replace whole PZT to press electric pottery and porcelain to have tremendous applied perspective. Filmy and deposit PZT presses the advantage of electric pottery and porcelain to include: Measure of better drop of control ink stick gray scale is worth and reduce power comsumption in order to adjust.

 

2007, aipusheng rolled out film to suppress report (TFP) prints a head, inside the range that uses Yu Aipu extensively to give birth to printer of old width of cloth. In September 2013, love general raw firm announces its are new generation ink jet prints a technology:

 

PrecisionCore, roll out the MEMS ink jet that uses PZT filmy technology to make to print a head for the first time, offer freeboard to print speed and admirable picture quality further.

 

 

Love general gives birth to PrecisionCore to print a head

 

Institute of the head that print uses the material that suppress report to press electric data for PZT thick film.

 

2, MEMS is opposite automatically anxious carry out implement

 

Current basically still rely on bulk automatically to anxious function tremendous, power consumption is tall and the phonic group electric machinery with high cost provides power. And those who be based on technology of the MEMS that suppress report is automatic already entered business to use level to anxious camera lens. Through on a few electrode that suppress report are being stuck on a thin glass, they can make glass bends, change polymer thereby piece the surface, make its become lens. Send momentum to decide curvature and decide a central issue because of this.

 

The MEMS that suppress report is opposite automatically anxious carry out implement principle graph

 

MEMS and VCM performance are comparative

 

It is PoLight on behalf of the enterprise, the film that uses meaning law semiconductor presses electric type technology, what its innovate is adjustable camera lens (TLens® , tuneable Lens) the form that changes aggregate film through pressing electric actuator, pair of anxious functions of imitate person eye. This application is regarded as camera to be opposite automatically anxious optimal solution. TLens camera lens can be finished for an instant right anxious, focus speed is traditional solution is decuple, and 1/20 what batteries power consumption has traditional plan only. In the meantime, the camera after taking a picture also has the progress that comparative automatically to anxious function afresh, what can provide successive stability like the task to photograph is automatic to anxious service.

 

 

Be opposite automatically anxious carry out implement what use the material that suppress report to press electric data for PZT thick film.

 

3, energy of MEMS of the type that suppress report is collected implement

 

From 1969 Wen.H.Ko is in patent (US Patent 3 456 134) in Liangshi energy collects the small-sized cantilever suppressing report that puts forward to collect palpitant activity energy one kind implement since, a lot of research groups on the world had been begun a series of collect about pressing electric type energy implement research. Use MEMS technology to make the energy that suppress report collect implement, can change miniature of parts of an apparatus, batch is changed, the other electronic parts such as the wireless sensor node that makes its and already progressively miniature are changed is nicer compositive together, final implementation is self-confessed can the system of small parts of an apparatus such as wireless sensor node. Current, MEMS pressing report is offerred can the system uses cantilever bridge structure more.

 

The wave shape AlN that university of American UC Berkeley designs presses electric energy to collect implement

 

MicroGen Systems company rolls out oscillatory energy to collect BOLT Power Cell, realized a real time wireless sensor network, the oscillatory energy of MEMS of the type that suppress report of MicroGen is collected implement or technology of small power generator has power supply.

 

 

The interior in MicroGen company BOLT Power Cell is chip of MEMS of a small-sized semiconductor, its use the craft that is similar to computer chip industry to undertake production. This chip is the type suppressing report that an area is 1.0cm2 about MEMS MPG, the small cantilever of extreme quality to load that its include to contain film of the type that suppress report. When as a result of the reason of exterior and oscillatory force fluctuation curves the cantilever when MPG, generation alternating current. When resonance AC power output is achieved the biggest, right now its are mixed in 120Hz for 100μW (about≥0.1g) and 900μW (are mixed in 600Hz ≥0.5g) . After collecting energy, its temporary memory is in the capacitor of a 300μF.

 

Energy is collected implement in what use the material that suppress report to be AlN and PZT film to press electric data commonly.

 

4, microphone of the MEMS that suppress report

 

Differ with microphone of capacitance type MEMS, the structure of microphone of the type that suppress report is relatively simple, it is a cantilever film that accompany sound to change and changes, produce the tension of enlarge directly through piezoelectric effect. As a result of principle of parts of an apparatus different, the design of the special enlarge circuit of this kind of microphone that suppress report compares capacitance style and character is simple a lot of—Because press electric type microphone not to need tall bias voltage or gain fine tuning, because this needs charge pump and circuit of gain fine tuning no longer piece, make the structure of follow-up processing circuit simple thereby, dimension is lesser also; Additional, also make without charge pump of microphone start be instantaneous almost and raised power source to restrain than (PSRR) .

 

Principle of microphone of capacitance type MEMS pursues

 

 

Press plan of principle of electric type microphone

 

Microphone of the MEMS that suppress report can be used at all environments such as the kitchen that indoor, outdoors, aerosol winds around, this reachs monitoring MEMS microphone to large speech control is very pivotal character for array, because be in such environment, the dependability of MEMS microphone array will be main problem. In addition, system of capacitance type microphone needs to last monitor the keyword such as similar “Alexa” or “Siri” , and microphone of the type that suppress report does not have charge pump, have the very short time that start. Accordingly, “ is in in microphone of MEMS of the type that suppress report permanent listening ” (Always Listening) when mode, their working total cycle time is very fast, can reduce the systematic specific power consumption of 90% .

 

Press electroacoustics sensor to be American Vesper company on behalf of the manufacturer, vesper is to come from Mixiegen the Bobby Littrell of the university and Karl Grosh found at 200 years, total position fills in at American horse cities of all a place of strategic importance are Bostonian, it is the company of MEMS newly established of hold of person of one family property. What Vesper product uses is technology of the type that suppress report. Nitrogen was solved to melt aluminium in with great concentration (AlN) filmy form sediment is accumulated technology and after difficult problem of a series of other key technology, vesper company established engineering group 2014 and the product put in in acting factory.

 

Vesper presses electric MEMS microphone place to use the material that suppress report to be AlN, the data suppressing report that the microphone of the MEMS that suppress report that additionally GMEMS of company of a newly established is rolled out uses is PZT.

 

5, ultrasonic dactylogram sensor

 

The dactylogram sensor that has commercialized at present is to be based on capacitance type principle more, need dactylogram contacts sensor directly. And the direct contact that ultrasonic sensor avoids dactylogram sensitization original and finger, avoided sweat smeary the influence that waits to identify successful rate to contact dactylogram, can undertake discriminating to dactylogram in indication screen lower part.

 

Ultrasonic dactylogram sensor uses the data that suppress report, the pulse echo of ultrasonic becomes the skin that resembles OK and penetrable finger, collect the image of dactylogram surface feature.

 

Sensor of odd chip ultrasonic

 

Connect a company high to released dactylogram of ultrasonic of Snapdragon Sense ID to identify a technology 2015, OK and built-in 3D is stereo dactylogram model, also can avoid the direct contact of dactylogram sensitization original and finger, avoided sweat smeary the influence that waits to identify successful rate to contact dactylogram, and can be used at plastic / glass / lower part of sapphirine substandard screen.

 

Connect chip of sensor of 3D ultrasonic dactylogram high (PMUT)

 

The 9 millet 5s that roll out introduced the smartphone product of this plan first times namely 2016, this also is ultrasonic dactylogram identifies a technology to be succeeded to apply first go up at the smartphone. But in light of the feedback from the user, its identify rate or presence a few problems. And the cost that ultrasonic dactylogram identifies modular group is higher also. Subsequently millet admiral machine also did not continue to use the ultrasonic dactylogram that connects high to identify a technology.

 

The data suppressing report that uses in ultrasonic dactylogram sensor is AlN.

 

6, ultrasonic gesticulation identifies sensor

 

Be based on light and photograph the system that resembles a head to identify workload big and power comsumption is tall, but the gesticulation of ultrasonic of have the aid of identifies, power comsumption can fall to a few small tile, can realize the ultrasonic sensor application in consuming an electron.

 

 

 

The principle that ultrasonic gesticulation identifies sensor is through suppressing report small treatment exceeds sonic transducer (PMUT) array gives out sound wave pulse, sound wave rebounds from the object to chip. Pass computation, chip can decide the object is opposite the position at equipment, and but farther compose builds 3D model, adversary situation undertakes discriminating.

 

It is what California uncle captures profit to achieve enterprise Chirp Microsystems newly on behalf of the enterprise, held water 2013, it is current the home commercializes PMUT and use exclusively at the company with air coupling supersonic type. Chirp is in CES technology was exhibited 2016 on held first time of supersonic gesticulation induction spectacular.

 

Ultrasonic gesticulation identifies what use in sensor to press electric data to be AlN and PZT material.

 

7, filter of body sound wave

 

Resonator of filmy body sound wave is one kind is based on theory of body sound wave, use acoustics resonance to realize electricity to choose the parts of an apparatus of frequency.

 

Principle of structure of resonator of filmy body sound wave pursues

 

Arrive when telegraphic date to load on the electrode of resonator of filmy body sound wave hind, through going against piezoelectric effect, stuff of the film that suppress report believes report a signal of translate into sound, travel to two electrode direction by the center. Advance when acoustical signal reach the summit of electrode on when low end of end and bottom electrode, the vast difference that fights as a result of acoustic resistance (the 1/30000-1/70000 that airy sound impedance has electrode material and impedance of sound of data of the layer that prop up only) , the serious excuse me of impedance causes the total reflection of sound wave, acoustical energy is centered accordingly reach the summit from face of lower end of the layer that prop up in the area that ply of the end panel on electrode is T. This ply formed F=v/ of a frequency for the area of T (2T) antrum of acoustics signal resonance, below working status, below piezoelectric effect of the material that suppress report and the joint action that go against piezoelectric effect, acoustical the resonance that resonance is the telegraphic date that is F to frequency with respect to expression. V is the velocity of wave of body sound wave, depend on the medium material of transmission.

 

The ply of the film that suppress report of FBAR measures level in micron, make its job frequency can raise GHz thereby. Additional, because press electric film too thin, because this FBAR must have the layer that prop up, evaporate metal electrode first when treatment or splash shoot the layer that prop up, next again again the preparation on electrode presses electric film, form the electrode on the metal on the film that suppress report again finally.

 

Solid state is assembled model (SMR) BAW filter, it uses the Prague layer technology in optics, in preparation of lower part of resonator bottom electrode tall, low alternant acoustical impedance layer, it is sound wave limitation thereby in the caboodle that suppress report. Prague reflector uses W and SiO2 to regard on any account as acoustics impedance layer commonly, because W is mixed,the acoustics impedance value between SiO2 differs bigger, and these two kinds of material are the material with standard CMOS commonly used craft. Its the biggest advantage is mechanical stability tall, compositive sex is good, and do not use MEMS technology. But defect is need preparation is multilayer film, process cost photograph relatively at cavity FBAR tall, and the effect of sound wave reflex of Prague reflector is inferior to air, the Q cost of SMR FBAR is relatively so a few lower.

 

Be based on the BAW filter sketch map of Prague reflector

 

At present the FBAR on the market is based on AlN to press electric film mostly.