CN104316577B

CN104316577B - A kind of methane transducer based on flip chip bonding encapsulation and preparation method and application

Info

Publication number: CN104316577B
Application number: CN201410607349.1A
Authority: CN
Inventors: 马洪宇; 丁恩杰; 刘晓文; 赵小虎; 程婷婷
Original assignee: China University of Mining and Technology CUMT
Current assignee: China University of Mining and Technology CUMT
Priority date: 2014-10-31
Filing date: 2014-10-31
Publication date: 2016-12-07
Anticipated expiration: 2034-10-31
Also published as: CN104316577A; WO2016066090A1

Abstract

A kind of miniature methane transducer based on flip chip bonding encapsulation and preparation method thereof, belongs to MEMS methane transducer and preparation method thereof.This methane transducer prepares monolithic high temperature heater and monolithic methane gas detector and ambient temperature sensor initially with MEMS technology processing, and then monolithic high temperature heater and monolithic methane gas detector are formed the miniature methane transducer of an overall laminated construction form by flip chip bonding encapsulation technology.Monolithic high temperature heater independent heating therein is to 500 DEG C of high temperature above；Monolithic methane gas detector independent detection declines because of the temperature that methane occurs and concentration change causes, and its measuring circuit is separate with the circuit of monolithic high temperature heater, is independent of each other.The preparation technology of this sensor is compatible with CMOS technology, and this methane transducer is low in energy consumption, highly sensitive, service life is long.

Description

A kind of methane transducer based on flip chip bonding encapsulation and preparation method and application

Technical field

The present invention relates to a kind of methane transducer and preparation method thereof, particularly one uses be applicable to industrial and mineral Internet of Things Methane transducer and preparation method and application based on flip chip bonding encapsulation.

Background technology

Along with the development of Internet of Things, current methane transducer cannot meet individual equipment to low-power consumption, long-life, low one-tenth The demand of the methane transducer of this detection low-concentration methane.Be currently used for underground coal mine detection low-concentration methane be still based on The catalytic combustion type methane transducer of tradition platinum filament heating, its power consumption is relatively big, and the especially use of catalyst causes CH_4 detection The shortcomings such as unstable properties, checking time are short；And infrared methane sensor price is high, sensing element is by dust and the serious shadow of steam Ring；Both methane transducers are not the most well positioned to meet the Internet of Things application demand to low-power consumption methane transducer.And other Methane transducer also cannot adapt to the environment of underground coal mine high humility.

Summary of the invention

The invention aims to provide a kind of simple in construction, heating element heater is parallel with measuring cell relative, makes measurement unit Part has a big temperature-sensitive area experiencing heating element heater high temperature, can highly sensitive detection low-concentration methane (0～4%) based on Methane transducer of flip chip bonding encapsulation and preparation method and application.

For above-mentioned technical purpose, it is an object of the invention to realize with flip chip bonding encapsulation technology based on MEMS process technology , specific as follows: monolithic high temperature heater, monolithic methane gas health check-up should to be included based on the miniature methane transducer of flip chip bonding encapsulation Survey device and ambient temperature sensor；

Described monolithic high temperature heater includes: bearing A, heating element heater, 2 fixing end A, 2 the fixing ends of bonding, Duo Ge electricity Pole exit, multiple support end；

Described monolithic methane gas detector includes bearing B, temperature element, 2 fixing end B, some bonding support ends；

Described ambient temperature sensor includes two electrode tips and measures resistance；Described ambient temperature sensor is located at monolithic On the bearing A of high temperature heater (HTH), or on the bearing B of monolithic methane gas detector, or monolithic high temperature heater bearing A with It is both provided with ambient temperature sensor on the bearing B of monolithic methane gas detector；

Described bearing A and bearing B includes the buried regions silicon oxide on silicon substrate and silicon substrate；

What the fixing end of described fixing end A, bonding, support end, electrode leads to client were the most independent with electrode tip is located at bearing A On buried regions silicon oxide on；Fixing end A and electrode tip are processed by silicon layer, and are provided with silicon oxide layer on silicon layer, at oxygen SiClx layer is provided with metal level；Being equipped with doped silicon layer in the silicon layer of described fixing end A and electrode tip, metal level is all by oxidation The window of silicon layer directly contacts with doped silicon layer and constitutes Ohmic contact；The fixing end of bonding, electrode leads to client and support end by Silicon layer processes, and is provided with silicon oxide layer on silicon layer, is provided with metal level on silicon oxide layer；Heating element heater is equally by silicon layer Process, and be provided with passivation protection layer at the outer surface of silicon layer；Described heating element heater is provided with high heating element, two symmetries The silicon cantilever arranged；Described high heating element is circular, or the parallel connection of multiple fire-bar；The length of described silicon cantilever is more than 300um；One end of described single silicon cantilever is connected with high heating element, the other end and the fixing end A phase of on bearing A Even；Electrode leads to client is also provided on the buried regions silicon oxide of bearing A；Each bonding fixes end, fixing electricity all corresponding with for end A One end of pole exit is connected, and especially metal level is connected to connect；Electrode leads to client is held away from fixing end A and bonding are fixing, After distance should make monolithic methane gas detector flip chip bonding on monolithic high temperature heating unit therebetween, electrode leads to client and electrode End is not blocked by monolithic methane gas detector, can outwards carry out wire bonding on electrode leads to client and electrode tip；At key Close fixing end, the metal level of support end is provided with the most identical metal coupling；2 fixing ends of bonding are with 2 fixing end A side by side Interval is arranged, respectively one the fixing end of bonding that puts in order, fixing end A, another fixing end A, another bonding are solid Fixed end；

Described temperature element is provided with temperature measuring unit, two symmetrically arranged linking arms, 2 symmetrically arranged support arms；Institute State temperature measuring unit, linking arm, support arm, fix and hold B to be sequentially connected；Described temperature measuring unit adds with the high temperature of monolithic high temperature heater Hot cell planform is identical, and size is slightly larger；What described bonding support end, fixing end B were the most independent is located at burying on bearing B On layer silicon oxide；If being provided with ambient temperature sensor on bearing B, then ambient temperature sensor and fixing end B and some be bonded Support end is separate, the connection not existed on silicon layer；Described bonding support end, fixing end B are processed by silicon layer, all wrap Include silicon layer, the silicon oxide layer being located at outside silicon layer, the metal level that is located on silicon oxide layer；It is provided with doped silicon in the silicon layer of fixing end B Layer, metal level directly contacts composition Ohmic contact by the doped silicon layer of the window of silicon oxide layer with fixing end B；Temperature element by Silicon layer processes, and is provided with passivation protection layer at the outer surface of silicon layer, and outstanding aerial temperature element is solid by fixing end It is scheduled on the buried regions silicon oxide on bearing B, two terminals of the electric pathway of two fixing end composition temperature elements；

The front of monolithic methane gas detector is parallel with the front of monolithic high temperature heater relative, after aligned by metal The metal bonding of salient point realizes being tightly fastened and electrically connecting of the two；Monolithic methane gas detector after alignment is at monolithic high temperature Projection properties on heater is: the fixing end of 2 of monolithic methane gas detector respectively with 2 keys of monolithic high temperature heater Close fixing end to overlap, the support end weight that the bonding support end of monolithic methane gas detector is corresponding with monolithic high temperature heater respectively Closing, the center superposition of the high heating element of the center of temperature measuring unit and monolithic high temperature heater, the center of the two is to respective Bearing has identical distance；Monolithic methane gas detector is fixed by metal salient point metal bonding with monolithic high temperature heater After, the distance range between the high heating element of temperature measuring unit and monolithic high temperature heater is 3 to 200um；Monolithic methane gas The temperature element of detector is by two fixing end B, two fixing ends of bonding of monolithic high temperature heater and metal thereon Two electrode leads to client that salient point end fixing with bonding is connected constitute a two-terminal device on monolithic high temperature heater, And hold two the electrode leads to client enterprising line leads bondings being connected can realize and external circuit in described fixing with bonding Connect；

The application process of a kind of miniature methane transducer based on flip chip bonding encapsulation, makes this encapsulate based on flip chip bonding during use The monolithic methane gas detector of miniature methane transducer be based on the monolithic of miniature methane transducer of flip chip bonding encapsulation Lower section on high temperature heater (HTH), passes to weak current to monolithic methane gas detector and ambient temperature sensor and does not make thermometric unit Part and measurement resistance heating；Then make heating element heats to the high temperature of more than 500 DEG C after being energized to monolithic high temperature heater, make Heating element heater enters the working region in its current-resistance characteristic curve on the left of turning point, and described turning point is that resistance is with electric current Or the point of greatest resistance that voltage increases and occurs, when curtage continues to increase, resistance does not continues to increase and reduces on the contrary； Power consumption is at about 100mW；When not having methane gas, the temperature element of monolithic methane gas detector is heated by heating element heater High temperature affects temperature and raises, and resistance increases；And when methane gas occurs and when concentration increases, the temperature of heating element heater reduces, Temperature element is affected by temperature also to be reduced, and causes the reduction of self-resistance, and the method then passing through electrical detection can detect The appearance of methane and methane concentration change；Temperature on the sheet of the miniature methane transducer of the ambient temperature sensor standalone probe present invention Temperature-compensating for methane concentration data.

The preparation method of miniature methane transducer based on flip chip bonding encapsulation, it includes two kinds of preparation methoies,

The monolithic high temperature heater of preparation method (one) first preparative separation and the monolithic methane gas detector separated, institute The monolithic high temperature heater monolithic methane gas detector stated uses soi wafer processing, monolithic high temperature heater and monolithic methane Can process on same soi wafer time prepared by detector, or process on different soi wafers；Then will processing The monolithic high temperature heater of good separation uses flip chip bonding encapsulation to be prepared as overall knot with the monolithic methane gas detector separated The miniature methane transducer of the present invention of configuration formula；

The concrete preparation process of preparation method () is:

The first step, prepares silicon oxide layer on soi wafer；

Second step, the silicon oxide layer on graphical top layer silicon, form the window needed for doping or ion implanting；

3rd step, doping or ion implanting form doped silicon layer；

4th step, prepares metal, and graphical prepared metal forms fixing end B, some bonding support ends, fixing end On A, bonding fixing end, support end, electrode leads to client with the metal level of electrode tip and fixing end A, be bonded to fix and holds and electrode Connection metal level between exit；

5th step, is lithographically formed the figure of the etching window of Facad structure, uses RIE dry etching to remove described quarter subsequently Erosion graph window in the first step generate silicon oxide layer and under silicon layer, etching stopping is in buried regions silicon oxide, at buried regions oxygen Heating element heater, fixing end A, the fixing end of bonding, electrode leads to client, multiple support end, measuring cell, thermometric unit is formed in SiClx Part, fixing end B, bonding support end and the structure of ambient temperature sensor and scribe line；

6th step, prepares etch-protecting layer in the front of soi wafer, uses photoresist or PSG (phosphorosilicate glass) as carving Erosion protective layer, described etch-protecting layer covers the front of whole soi wafer；

7th step, is lithographically formed the figure of back-etching window at the soi wafer back side, use wet etching or ICP or The bottom silicon of the dry etching method etching soi wafers such as DRIE, i.e. substrate, etching stopping is in buried regions silicon oxide；

8th step, uses the buried regions silicon oxide that hydrofluoric acid solution or Fluohydric acid. aerosol wet etching expose, release from substrate Go out heating element heater, temperature element；

9th step, removes the etch-protecting layer that the 6th step is formed；

Tenth step, aoxidizes the silicon exposed, and forms oxide thin layer silicon layer；

11st step, uses protective layer to cover the front of soi wafer, and described protective layer covers except heating element heater, thermometric unit Soi wafer front portion beyond the measurement resistance of part hanging structure and ambient temperature sensor；Photoresist conduct can be used Protective layer；Micro-spray printing device can be used to prepare described photoresist after being accurately positioned；It is used as covering covering in the front of SOI Cover version use spraying method prepare described photoresist, described in shelter version expose except heating element heater, temperature element hanging structure with And the measurement resistance of ambient temperature sensor, remaining masked version in soi wafer front portion shelters from；

12nd step, uses ALD Atomic layer deposition method to examine in thermal element, temperature element hanging structure and ambient temperature The outer surface measuring resistance surveying device prepares hafnium oxide, or prepares aluminum oxide film, or it is thin to prepare hafnium oxide/alumina composite Film, or prepare silicon oxide/hafnium oxide/alumina composite thin film, the oxide thin layer silicon layer formed with the tenth step collectively forms passivation Protective layer；

13rd step, removes protective layer prepared by the 11st step, is dried；

14th step, obtains large number of discrete monolithic high temperature heater and discrete monolithic methane after scribing, sliver Detector；

15th step, fits the front of the monolithic high temperature heater prepared with the front of monolithic methane gas detector Alignment, fixes the metal coupling on the metal level of end, support end and corresponding monolithic by the bonding of monolithic high temperature heater subsequently Fixing end B on methane gas detector, the metal on bonding support end contact and apply pressure, heating up carries out bonding formation The miniature methane transducer of the present invention of overall laminated construction form；

Or preparation method (two) is the wafer level flip chip bonding encapsulation preparation miniature methane transducer described in claim 1, single Sheet high temperature heater (HTH) is processed on a SOI silicon wafer, and monolithic methane gas detector is processed on another SOI silicon wafer； Then the miniature methane transducer of wafer level flip chip bonding encapsulation preparation cost invention is used.

Preparation method (two) concretely comprise the following steps:

The first step, prepares silicon oxide layer on soi wafer；

3rd step, doping or ion implanting form doped silicon layer；

4th step, prepares metal, and graphical prepared metal forms fixing end B, some bonding support ends, solid respectively Fixed end A, the fixing end of bonding, support end, electrode leads to client and the metal level on electrode tip and fixing end A, be bonded fix hold and Connection metal level between electrode leads to client；

5th step, is lithographically formed the figure of the etching window of Facad structure, uses RIE dry etching to remove described quarter subsequently Erosion graph window in the first step generate silicon oxide layer and under silicon layer, etching stopping is in buried regions silicon oxide, at buried regions oxygen Heating element heater, fixing end A, the fixing end of bonding, electrode leads to client, multiple support end, measuring cell, thermometric unit is formed in SiClx Part, fixing end B, bonding support end and the structure of ambient temperature sensor；

7th step, is lithographically formed the etching window figure of back side scribe line at the back side of SOI silicon wafer, uses RIE etching The silicon oxide at the soi wafer back side and bottom silicon, form scribe line；

8th step, is lithographically formed back-etching graph window at the soi wafer back side, uses wet etching or ICP or DRIE Deng dry etching method etching soi wafer bottom silicon, i.e. substrate, etching stopping in buried regions silicon oxide, discharge heating element heater, Temperature element；

9th step, uses the buried regions silicon oxide that hydrofluoric acid solution or Fluohydric acid. aerosol wet etching expose, release from substrate Go out heating element heater, temperature element；

Tenth step, removes the etch-protecting layer that the 6th step is formed；

11st step, aoxidizes the silicon exposed, and forms oxide thin layer silicon layer；

12nd step, uses protective layer to cover the front of soi wafer, and described protective layer covers except heating element heater, thermometric unit Soi wafer front portion beyond the measurement resistance of part hanging structure and ambient temperature sensor；Photoresist conduct can be used Protective layer；Micro-spray printing device can be used to prepare described photoresist after being accurately positioned；It is used as covering covering in the front of SOI Covering version uses the method for spraying to prepare described photoresist, described in shelter version and expose except heating element heater 103, temperature element 203 are unsettled The measurement resistance 1032 of structure and ambient temperature sensor 3, remaining masked version in soi wafer front portion shelters from；

13rd step, uses ALD Atomic layer deposition method to examine in thermal element, temperature element hanging structure and ambient temperature The outer surface measuring resistance surveying device prepares hafnium oxide, or prepares aluminum oxide film, or it is thin to prepare hafnium oxide/alumina composite Film, or prepare silicon oxide/hafnium oxide/alumina composite thin film, constitute blunt together with the oxide thin layer silicon layer formed with the 11st step Change protective layer；

14th step, removes protective layer prepared by the 12nd step, is dried；

The above-mentioned first step to the 14th step is that monolithic high temperature heater, monolithic methane gas detector are at respective SOI silicon circle Procedure of processing on sheet；

15th step, has monolithic methane gas health check-up by the front preparing the silicon wafer of monolithic high temperature heater with preparation Survey the front laminating alignment of the silicon wafer of device, subsequently the bonding of monolithic high temperature heater is fixed on the metal level of end, support end Metal coupling end fixing with on corresponding monolithic methane gas detector B, some bonding support ends contact and apply pressure, liter Temperature carries out bonding and forms the silicon wafer containing monolithic high temperature heater is one with the silicon wafer containing monolithic methane gas detector The laminated type silicon wafer of body；

16th step, has drawing on the SOI silicon wafer back side of monolithic methane gas detector along described in the 7th step in preparation Film trap scribing, along the thickness of the depth of cut only one of which SOI silicon wafer of scribe line scribing described in this step, gets rid of described system Have the silicon of cutting on the SOI silicon wafer of monolithic methane gas detector, expose the electrode on monolithic high temperature heater and draw End；

17th step, has the scribe line on the SOI silicon wafer back side of monolithic high temperature heater along described in the 7th step in preparation Scribing；It is the thickness of two SOI silicon wafers along the depth of cut of scribe line scribing described in this step；Obtain the present invention's after sliver Miniature methane transducer based on flip chip bonding encapsulation.

Beneficial effect, first adding with SOI silicon wafer for substrate employing MEMS technology of the miniature methane transducer of the present invention Work order sheet high temperature heater (HTH), monolithic methane gas detector and border temperature detector, use flip chip packaging method to obtain then The miniature methane transducer based on flip chip bonding encapsulation of the present invention, owing to have employed such scheme, has following effective effect:

1, the methane transducer of the present invention does not use catalyst, uses monolithic high temperature heater to detect with monolithic methane gas Device just can realize the detection of low-concentration methane gas；Meanwhile, the detection of methane is joined by the methane transducer of the present invention without oxygen With, do not affected by oxygen in air；

2, the temperature element of the monolithic methane gas detector of the present invention has and the heating element heater of monolithic high temperature heater Identical shape, and parallel relatively by the face, form face of lamination, make the thermometric unit of the monolithic methane gas detector of the present invention Part has a bigger heating surface area, the single-chip integration mode of independent high heating element and independent temperature detector then without Method realizes the sensible heat area that temperature detector of the present invention is big, therefore makes the temperature element of the monolithic methane gas detector of the present invention The significantly more efficient feeling of independence of energy is by the temperature information of high heating element；Above-mentioned factor all makes the methane of the present invention sense Utensil has higher sensitivity；

3, the methane transducer of the present invention does not contains catalyst and catalytic carrier, and therefore, the performance of sensor is not catalyzed The impact of agent, do not exist catalyst activity reduce cause sensitivity decrease, be poisoned, the problem such as activation；

4, the silicon heater of the methane transducer of the present invention is all suspended in sky with the temperature element of monolithic methane gas detector In gas and away from respective bearing, silicon heater, more than more than 300um, can be heated to 500 with relatively low electrical power by distance High temperature more than DEG C, therefore has advantage low in energy consumption；Secondly, the heating element heater of the monolithic high temperature heater of the present invention and monolithic The temperature element of methane gas detector is separate, the most directly contacts, and the most there is not solid state medium and connects, does not exists The energy loss of the conduction of heat form from heating element heater to temperature element, therefore effectively reduces the heating of monolithic high temperature heater Power consumption when being heated to duty of element；Further, of the methane transducer of the present invention only monolithic high temperature heater adds Thermal element requires heat to high temperature；The temperature element of monolithic methane gas detector and ambient temperature sensor the most only need extremely low Electric current gets final product work, and without being heated to high temperature, therefore the temperature element of monolithic methane gas detector detects with ambient temperature The power consumption of device is the most extremely low；Further, in use, monolithic methane gas detector is positioned at the lower section of monolithic high temperature heater, and this is also Contribute to reducing the power consumption of the heating element heater of high temperature heater (HTH)；Above-mentioned aggregate measures make the entirety of the methane transducer of the present invention Power consumption is greatly reduced；

5, the heating element heater of monolithic high temperature heater of the present invention, the temperature element of monolithic methane gas detector, environment The measurement resistance of temperature detector is all silicon materials so that processing technique is unified, simple, cost is relatively low；

6, the heating element heater of monolithic high temperature heater of the present invention, the temperature element of monolithic methane gas detector are all adopted Processing with the monocrystal silicon of stable performance and obtain, it is good steady that this makes the methane transducer of the present invention have under hot operation state Qualitative with the long life-span；Hold this is because monocrystal silicon does not exist the METAL HEATING PROCESS material such as platinum, tungsten high temperature more than 500 degrees Celsius The shortcomings such as volatile, migration, the most there is not polysilicon resistance at high temperature grain boundary resistance and be prone to change, the shortcoming that cannot control； Meanwhile, in the heating element heater of monolithic high temperature heater, the temperature element of monolithic methane gas detector and the environment temperature of the present invention The passivation layer that the outer surface measuring resistance of degree detector is arranged also reduces the external environment impact on above-mentioned components and parts, thus Further increase the stability of the methane transducer performance of the present invention；

7, the heating element heater of monolithic high temperature heater of the miniature methane transducer of the present invention, monolithic methane gas detector Temperature element and ambient temperature sensor achieve the independence in structure, no longer by traditional single element heating and thermometric merit The restriction of energy multiplexing, can individually regulate and control heating element heater, individually detect temperature element simultaneously, and heating does not exists with thermometric Coupling, thus heating element heater can be regulated and controled the most accurately with temperature element, this makes the methane transducer of the present invention to have There is multiple-working mode, and make regulation and control configuration simple, flexible, then improve intelligent level and the sensitivities of methane transducer Energy；

8, the ambient temperature sensor of the present invention is used for independent detection ambient temperature, and the CH_4 detection that this is the present invention provides With heating element heater, the raising of temperature element temperature data closest, the most real, beneficially temperature compensation characteristic, simultaneously Also good basis is provided for methane transducer intellectuality；

9, the methane transducer of the present invention uses MEMS technology processing, and size is little not only makes biosensor power consumption low, and rings Answer speed fast, up to about 40ms；Owing to using the monolithic methane gas detector detection methane concentration that self-heating effect is low, its The reduction of thermal noise makes the sensitivity of sensor be improved；

10, the methane transducer of the present invention can use CMOS technology to produce in batches, can have good concordance, therefore also Can calibrate in batches, therefore can improve sensor performance further and reduce the cost of pick up calibration link；

Advantage: a kind of based on flip chip bonding encapsulation the miniature methane transducer of the present invention, only uses a high-temperature heating unit Part, overall power is low；The temperature element arranged has bigger heating surface area, makes sensitivity obtain higher；There is longer making Use the life-span；Its preparation method can be compatible with CMOS technology, and batch making can reduce cost and improve concordance；It is prone to carry out temperature Degree compensates；Can calibrate in batches；Disclosure satisfy that the underground coal mine environment Internet of Things individual equipment demand to high-performance methane transducer.

Accompanying drawing explanation

Fig. 1 (a) is the structure of the monolithic high temperature heater of the miniature methane transducer based on flip chip bonding encapsulation of the present invention Schematic diagram.

Fig. 1 (b) is the monolithic methane gas detector of the miniature methane transducer based on flip chip bonding encapsulation of the present invention Structural representation.

Fig. 2 is the structural representation of the fixing end B of the Section A-A sectional view in Fig. 1, i.e. monolithic methane gas detector.

Fig. 3 is the version of high heating element employing multiple fire-bars parallel connection of the monolithic high temperature heater of the present invention Schematic diagram.

Fig. 4 is the order signal of the flip chip bonding encapsulation system of the miniature methane transducer based on flip chip bonding encapsulation of the present invention Figure.

Fig. 5 is placement schematic diagram during the miniature methane transducer based on flip chip bonding encapsulation using the present invention.

The current-resistance characteristic curve of the heating element heater of the monolithic high temperature heater of Fig. 6 present invention.

In figure: 1-monolithic high temperature heater, 2-monolithic methane gas detector, 3-ambient temperature sensor, 11-silicon serves as a contrast The end, 12-buried regions silicon oxide, 21-silicon layer, 22-metal level, 23-silicon oxide layer, 24-doped silicon layer, 25-passivation protection layer, 101- Bearing A, 102-fixing end A, 103-heating element heater, 104-electrode leads to client, 105-support end, 106-bonding fixing end A, 201- Bearing B, 202-fixing end B, 203-temperature element, 204-is bonded support end B, 500-metal salient point, 1031-high-temperature heating list Unit, 1032-silicon cantilever, 1041-electrode tip, 1041-electrode tip, 2031-temperature measuring unit, 2032-support arm, 2033-linking arm.

Detailed description of the invention

Below in conjunction with the accompanying drawings one embodiment of the present of invention is further described:

In Fig. 1 (a), Fig. 1 (b), Fig. 2, Fig. 3, this miniature methane transducer includes shown monolithic high temperature heater, monolithic Methane gas detector and ambient temperature sensor；

Described monolithic high temperature heater 1 includes: bearing A 101, heating element heater 103,2 fixing end A 102,2 bonding Fixing end A106, multiple electrode leads to client 104, multiple support end 105；

Described monolithic methane gas detector 2 includes bearing B 201, temperature element 203,2 fixing end B 202, some Bonding support end 204；

Described ambient temperature sensor 3 includes two electrode tips 1041 and measures resistance 32；Described ambient temperature sensor 3 It is located on the bearing A 101 of monolithic high temperature heater 1, or on the bearing B 201 of monolithic methane gas detector 2, or at monolithic It is both provided with ambient temperature detection on the bearing A 101 and the bearing B 201 of monolithic methane gas detector 2 of high temperature heater (HTH) 1 Device 3；

Described bearing A 101 and bearing B 201 includes the buried regions silicon oxide 12 on silicon substrate 11 and silicon substrate 11；

Described fixing end A 102, bonding fixing end A106, support end 105, electrode leads to client 104 are equal with electrode tip 1041 On the separate buried regions silicon oxide 12 being located on bearing A 101；Fixing end A 102 and electrode tip 1041 are added by silicon layer 21 Work forms, and is provided with silicon oxide layer 23 on silicon layer 21, is provided with metal level 22 on silicon oxide layer 23；Described fixing end A 102 And in the silicon layer 21 of electrode tip 1041, it being equipped with doped silicon layer 24, metal level 22 is all by window and the doped silicon of silicon oxide layer 23 Layer 24 directly contacts and constitutes Ohmic contact；Bonding fixing end A106, electrode leads to client 104 and support end 105 are by silicon layer 21 Process, and on silicon layer 21, be provided with silicon oxide layer 23, silicon oxide layer 23 is provided with metal level 22；Heating element heater 103 is same Sample is processed by silicon layer 21, and is provided with passivation protection layer 25 at the outer surface of silicon layer 21；Described heating element heater 103 is provided with high temperature 1031, two symmetrically arranged silicon cantilevers 1032 of heating unit；Described high heating element 1031 is circular, or is such as Fig. 3 The parallel connection of shown multiple fire-bars 1013；The length of described silicon cantilever 1032 is more than 300um；Described single silicon cantilever 1032 One end is connected with high heating element 1031, and the other end is connected with the fixing end A102 of on bearing A101；Electrode leads to client 104 are also provided on the buried regions silicon oxide 12 of bearing A 101；Each bonding fixing end A106, fixing end A 102 are all corresponding with one One end of electrode leads to client 104 be connected, especially metal level 22 is connected to connect；Electrode leads to client 104 is away from fixing end A 102 and bonding fixing end A106, distance should make monolithic methane gas detector 2 flip chip bonding on monolithic high temperature heating unit therebetween After 1, electrode leads to client 104 and electrode tip 1041 are not blocked by monolithic methane gas detector 2, electrode leads to client 104 He Wire bonding can be outwards carried out on electrode tip 1041；The fixing metal level 22 holding A106, support end 105 of bonding is provided with height Spend identical metal coupling 500；2 bonding fixing end A106 and 2 fixing end A 102 spacing side by side layouts, put in order point It is not a bonding fixing end A106, fixing end A102, another fixing end A 102, another bonding fixing end A106；

Temperature element 203 as described in Fig. 1 (b) is provided with the symmetrically arranged linking arm of temperature measuring unit 2031, two 2033,2 Symmetrically arranged support arm 2032；Described temperature measuring unit 2031, linking arm 2033, support arm 2032, fixing end B 202 phase successively Even；Described temperature measuring unit 2031 is identical with high heating element 1031 planform of monolithic high temperature heater 1, and size is slightly larger； On described bonding support end 204, the fixing buried regions silicon oxide 12 being located on bearing B 201 the most independent for end B 202；If Bearing B 201 is provided with ambient temperature sensor 3, then ambient temperature sensor 3 and fixing end B 202 and some be bonded support end Connection 204 separate, that do not exist on silicon layer 21；Described bonding support end 204, fixing end B 202 are processed by silicon layer 21 Form, the silicon oxide layer 23 that all include silicon layer 21, is located at outside silicon layer 21, the metal level 22 being located on silicon oxide layer 23；Fixing end B Being provided with doped silicon layer 24 in the silicon layer 21 of 202, metal level 22 is by the doped silicon of the window of silicon oxide layer 23 with fixing end B 202 Layer 24 directly contact constitutes Ohmic contact；Temperature element 203 is processed by silicon layer 21, and is provided with blunt at the outer surface of silicon layer 21 Changing protective layer 25, the buried regions that outstanding aerial temperature element 203 is fixed on bearing B 201 by fixing end B 202 aoxidizes On silicon 12, two terminals of two fixing electric pathways holding B 202 to constitute temperature element 203；

The front of monolithic methane gas detector 2 is parallel with the front of monolithic high temperature heater 1 relative, after aligned by gold The metal bonding belonging to salient point 500 realizes being tightly fastened and electrically connecting of the two；Monolithic methane gas detector 2 after alignment is at list Projection properties on sheet high temperature heater (HTH) 1 is: 2 of monolithic methane gas detector 2 fixing end B 202 respectively with monolithic high temperature 2 bonding fixing end A106 of heater 1 overlap, and the bonding support end 204 of monolithic methane gas detector 2 is high with monolithic respectively The support end 105 of temperature heater 1 correspondence overlaps, the center of temperature measuring unit 2031 and the high-temperature heating list of monolithic high temperature heater 1 The center superposition of unit 1031, the center of the two has identical distance to respective bearing；Monolithic methane gas detector 2 is with single After sheet high temperature heater (HTH) 1 is fixed by metal salient point 500 metal bonding, temperature measuring unit 2031 and the height of monolithic high temperature heater 1 Distance range between temperature heating unit 1031 is 3 to 200um；The temperature element 203 of monolithic methane gas detector 2 is by two Individual fixing end B 202, two bondings of monolithic high temperature heater 1 are fixed end A106 and metal salient point thereon 500 and are bonded solid Two electrode leads to client 104 that fixed end A106 is connected constitute a two-terminal device on monolithic high temperature heater 1, described Two electrode leads to client 104 enterprising line leads bondings being connected of end A106 fixing with bonding can realize the company with external circuit Connect.

The application process of a kind of miniature methane transducer based on flip chip bonding encapsulation, as it is shown in figure 5, make monolithic first during use Alkane detector 2 is positioned at the lower section of 1 on monolithic high temperature heater.Detect with ambient temperature to monolithic methane gas detector 2 Device 3 passes to weak current does not make temperature element 203 generate heat with measuring resistance 32；Then make to monolithic high temperature heater 1 after being energized Heating element heater 103 is heated to the high temperature of more than 500 DEG C, makes heating element heater 103 be operated in current-resistance characteristic as shown in Figure 6 Working region on the left of turning point in curve, described turning point is that resistance increases with curtage and the resistance that occurs is maximum Point, when curtage continues to increase, resistance does not continues to increase and reduces on the contrary；The power consumption of heating element heater 103 is left at 100mW Right；When not having methane gas, the temperature element 203 of monolithic methane gas detector 2 is by the heating high temperature shadow of heating element heater 103 Ringing temperature to raise, resistance increases；And when methane gas occurs and when concentration increases, the temperature of heating element heater 103 reduces, thermometric Element 203 is affected by temperature also to be reduced, and causes the reduction of self-resistance, and the method then passing through electrical detection can detect first The appearance of alkane and methane concentration change；Temperature on the sheet of the miniature methane transducer of the ambient temperature sensor 3 standalone probe present invention Temperature-compensating for methane concentration data.

The preparation method of miniature methane transducer based on flip chip bonding encapsulation, including two kinds of preparation methoies:

The monolithic high temperature heater 1 of preparation method (one) first preparative separation and the monolithic methane gas detector 2 separated, Described monolithic high temperature heater 1 monolithic methane gas detector 2 uses soi wafer to process, monolithic high temperature heater 1 and monolithic Can process on same soi wafer time prepared by methane gas detector 2, or process on different soi wafers；Then will The monolithic high temperature heater 1 of the separation processed uses flip chip bonding encapsulation to be prepared as with the monolithic methane gas detector 2 separated The miniature methane transducer of the present invention of overall structure form.

The concrete preparation process of preparation method () is:

The first step, prepares silicon oxide layer 23 on soi wafer；

Second step, the silicon oxide layer 23 on graphical top layer silicon, form the window needed for doping or ion implanting；

3rd step, doping or ion implanting form doped silicon layer 24；

4th step, prepares metal, and graphical prepared metal forms fixing end B 202, some bonding support ends 204, the metal level with electrode tip 1041 on end A 102, bonding fixing end A106, support end 105, electrode leads to client 104 is fixed 22 and fixing end A 102, the connection metal level between bonding fixing end A106 and electrode leads to client 104；

5th step, is lithographically formed the figure of the etching window of Facad structure, uses the RIE dry etching first step to generate subsequently Silicon oxide layer 23 and under silicon layer 21, etching stopping in buried regions silicon oxide 12, on buried regions silicon oxide 12 formed heating unit Part 103, fixing end A 102, bonding fixing end A106, electrode leads to client 104, multiple support end 105, measuring cell 102, thermometric Element 203, fixing end B 202, bonding support end 204 and the structure of ambient temperature sensor 3 and scribe line；

7th step, is lithographically formed the figure of back-etching window at the soi wafer back side, uses wet etching or ICP (Inductively Coupled Plasma, sense coupling) or DRI (Deep Reactive Ion Etching, deep reaction ion etching) etc. the bottom silicon of dry etching method etching soi wafer, i.e. substrate 11, etching stopping in Buried regions silicon oxide 12；

8th step, uses the buried regions silicon oxide 12 that hydrofluoric acid solution or Fluohydric acid. aerosol wet etching expose from substrate 11, Discharge heating element heater 103, temperature element 203；

9th step, removes the etch-protecting layer that the 7th step is formed；

11st step, uses protective layer to cover the front of soi wafer, and described protective layer covers except heating element heater 103, thermometric Soi wafer front portion beyond the measurement resistance 1032 of element 203 hanging structure and ambient temperature sensor 3；Can use Photoresist is as protective layer；Micro-spray printing device can be used to prepare described photoresist after being accurately positioned；It is used as covering at SOI Front shelter version use spraying method prepare described photoresist, described in shelter version expose except heating element heater 103, thermometric unit The measurement resistance 1032 of part 203 hanging structure and ambient temperature sensor 3, and remaining soi wafer front portion is masked Version shelters from；

12nd step, uses ALD (ald) method at thermal element 103, temperature element 203 hanging structure and ring The outer surface measuring resistance 1032 of border temperature detector 3 prepares hafnium oxide, or prepares aluminum oxide film, or prepare hafnium oxide/ Alumina composite thin film, or prepare silicon oxide/hafnium oxide/alumina composite thin film, the oxide thin layer silicon formed with the 11st step Layer collectively forms passivation protection layer 25；

13rd step, removes protective layer prepared by the 12nd step, is dried；

14th step, obtains large number of discrete monolithic high temperature heater 1 and discrete monolithic methane after scribing, sliver Detector 2；

15th step, as shown in Figure 4, detects the front of the monolithic high temperature heater 1 prepared with monolithic methane gas Front laminating alignment (by a to b) of device 2；Subsequently by bonding fixing end A106, the gold of support end 105 of monolithic high temperature heater 1 Belong to the metal coupling 500 on layer 22 and the fixing end B 202 on corresponding monolithic methane gas detector 2, bonding support end 204 On metal contact and apply pressure, heating up carries out bonding and forms as shown in Figure 5 this of overall laminated construction form Bright miniature methane transducer (by b to c).

Or preparation method (two) is the wafer level flip chip bonding encapsulation preparation miniature methane transducer described in claim 1, single Sheet high temperature heater (HTH) 1 is processed on a SOI silicon wafer, and monolithic methane gas detector 2 adds on another SOI silicon wafer Work；Then the miniature methane transducer of wafer level flip chip bonding encapsulation preparation cost invention is used.

Preparation method (two) concretely comprise the following steps:

The first step, prepares silicon oxide layer 23 on soi wafer；

3rd step, doping or ion implanting form doped silicon layer 24；

4th step, prepares metal, and graphical prepared metal forms fixing end B 202 respectively, some bondings support End 204, fixing end A 102, bonding fixing end A106, support end 105, electrode leads to client 104 and the metal on electrode tip 1041 Layer 22 and fixing end A 102, connection metal level between bonding fixing end A106 and electrode leads to client 104；

5th step, is lithographically formed the figure of the etching window of Facad structure, uses RIE dry etching to remove described quarter subsequently Silicon oxide layer 23 that the first step in erosion graph window generates and under silicon layer 21, etching stopping in buried regions silicon oxide 12, Heating element heater 103, fixing end A 102, bonding fixing end A106, electrode leads to client 104, Duo Gezhi is formed on buried regions silicon oxide 12 Support end 105, measuring cell 102, temperature element 203, fixing end B 202, bonding support end 204 and ambient temperature sensor 3 Structure；

8th step, is lithographically formed back-etching graph window at the soi wafer back side, uses wet etching or ICP or DRIE The bottom silicon of the dry etching method etching soi wafers such as deep reaction ion etching, i.e. substrate 11, etching stopping is in buried regions silicon oxide 12；

9th step, uses the buried regions silicon oxide 12 that hydrofluoric acid solution or Fluohydric acid. aerosol wet etching expose from substrate 11, Discharge heating element heater 103, temperature element 203；

Tenth step, removes the etch-protecting layer that the 6th step is formed；

12nd step, uses protective layer to cover the front of soi wafer, and described protective layer covers except heating element heater 103, thermometric Soi wafer front portion beyond the measurement resistance 1032 of element 203 hanging structure and ambient temperature sensor 3；Can use Photoresist is as protective layer；Micro-spray printing device can be used to prepare described photoresist after being accurately positioned；It is used as covering at SOI Front shelter version use spraying method prepare described photoresist, described in shelter version expose except heating element heater 103, thermometric unit The measurement resistance 1032 of part 203 hanging structure and ambient temperature sensor 3, and remaining soi wafer front portion is masked Version shelters from；

13rd step, uses ALD method at thermal element 103, temperature element 203 hanging structure and ambient temperature sensor The outer surface measuring resistance 1032 of 3 prepares hafnium oxide, or prepares aluminum oxide film, or it is thin to prepare hafnium oxide/alumina composite Film, or prepare silicon oxide/hafnium oxide/alumina composite thin film, constitute blunt together with the oxide thin layer silicon layer formed with the 11st step Change protective layer 25；

14th step, removes protective layer prepared by the 12nd step, is dried；

The above-mentioned first step to the 14th step is that monolithic high temperature heater 1, monolithic methane gas detector 2 are at respective SOI silicon Procedure of processing on disk；

15th step, has monolithic methane gas by the front preparing the silicon wafer of monolithic high temperature heater 1 with preparation The front laminating alignment of the silicon wafer of detector 2, subsequently by the bonding of monolithic high temperature heater 1 fixing end A106, support end 105 Metal level 22 on metal coupling 500 end fixing with on corresponding monolithic methane gas detector 2 B 202, some bondings prop up Support end 204 to contact and apply pressure, heat up to carry out being bonded being formed and contain the silicon wafer of monolithic high temperature heater 1 and containing monolithic first The laminated type silicon wafer that the silicon wafer of alkane detector 2 is integrated；

16th step, has drawing on the SOI silicon wafer back side of monolithic methane gas detector 2 along described in the 7th step in preparation Film trap scribing, along the thickness of the depth of cut only one of which SOI silicon wafer of scribe line scribing described in this step, gets rid of described system Having the silicon of cutting on the SOI silicon wafer of monolithic methane gas detector 2, the electrode exposed on monolithic high temperature heater 1 draws Go out end 104；

17th step, has the scribe line on the SOI silicon wafer back side of monolithic high temperature heater 1 along described in the 7th step in preparation Scribing；It is the thickness of two SOI silicon wafers along the depth of cut of scribe line scribing described in this step；Sliver obtains the base of the present invention Miniature methane transducer in flip chip bonding encapsulation.

Claims

1. one kind based on flip chip bonding encapsulation miniature methane transducer, it is characterised in that: it include monolithic high temperature heater (1), Monolithic methane gas detector (2) and ambient temperature sensor (3)；

Described monolithic high temperature heater (1) including: bearing A(101), heating element heater (103), 2 fixing end A(102), 2 keys Close fixing end A(106), multiple electrode leads to client (104), multiple support end (105)；

Described monolithic methane gas detector (2) includes bearing B(201), temperature element (203), 2 fixing end B(202) if Dry bonding support end (204)；

Described ambient temperature sensor (3) includes two electrode tips (1041) and measures resistance (32)；Described ambient temperature detects Device (3) is located at the bearing A(101 of monolithic high temperature heater (1)) on, or the bearing B(201 of monolithic methane gas detector (2)) On, or the bearing A(101 at monolithic high temperature heater (1)) with the bearing B(201 of monolithic methane gas detector (2)) on all set It is equipped with ambient temperature sensor (3)；

Described bearing A(101) and bearing B(201) all include the buried regions silicon oxide on silicon substrate (11) and silicon substrate (11) (12)；

Described fixing end A(102), bonding fixing end A(106), support end (105), electrode leads to client (104) and electrode tip (1041) the most independent be located at bearing A(101) on buried regions silicon oxide (12) on；Fixing end A(102) and electrode tip (1041) processed by silicon layer (21), and on silicon layer (21), be provided with silicon oxide layer (23), set on silicon oxide layer (23) There is metal level (22)；Described fixing end A(102) and the silicon layer (21) of electrode tip (1041) in be equipped with doped silicon layer (24), gold Belong to layer (22) all directly contact by the window of silicon oxide layer (23) with doped silicon layer (24) and constitute Ohmic contact；Bonding is fixing End A(106), electrode leads to client (104) processes by silicon layer (21) with support end (105), and is provided with on silicon layer (21) Silicon oxide layer (23), is provided with metal level (22) on silicon oxide layer (23)；Heating element heater (103) is equally by silicon layer (21) processing Become, and be provided with passivation protection layer (25) at the outer surface of silicon layer (21)；Described heating element heater (103) is provided with high heating element (1031), two symmetrically arranged silicon cantilevers (1032)；Described high heating element (1031) is circular, or multiple fire-bar Parallel connection；The length of described silicon cantilever (1032) is more than 300um；One end of described single silicon cantilever (1032) and high-temperature heating Unit (1031) is connected, the other end and bearing A(101) on one fixing hold A(102) be connected；Electrode leads to client (104) also sets At bearing A(101) buried regions silicon oxide (12) on；Each bonding fixing end A(106), fixing end A(102) all corresponding with one One end of electrode leads to client (104) be connected, especially metal level (22) is connected to connect；Electrode leads to client (104) is away from solid Fixed end A(102) and bonding fixing end A(106), distance should make monolithic methane gas detector (2) flip chip bonding high at monolithic therebetween On temperature heating unit after (1), electrode leads to client (104) and electrode tip (1041) are not hidden by monolithic methane gas detector (2) Gear, can outwards carry out wire bonding on electrode leads to client (104) and electrode tip (1041)；At bonding fixing end A(106), The metal level (22) of support end (105) is provided with the most identical metal coupling (500)；2 bonding fixing end A(106) and 2 Fixing end A(102) spacing side by side arranges, put in order respectively one bonding fixing end A(106), a fixing end A(102), Another fixing end A(102), another bonding fixing end A(106)；

Described temperature element (203) is provided with temperature measuring unit (2031), two symmetrically arranged linking arms (2033), and 2 symmetries set The support arm (2032) put；Described temperature measuring unit (2031), linking arm (2033), support arm (2032), fixing end B(202) depend on Secondary connected；Described temperature measuring unit (2031) is identical with the high heating element of monolithic high temperature heater (1) (1031) planform, Size is slightly larger；Described bonding support end (204), fixing end B(202) the most independent be located at bearing B(201) on buried regions oxygen In SiClx (12)；If at bearing B(201) on be provided with ambient temperature sensor (3), then ambient temperature sensor (3) and fixing end B And some bonding support ends (204) are separate, the connection that do not exists on silicon layer (21) (202)；Described bonding support end (204), end B(202 is fixed) processed by silicon layer (21), all include silicon layer (21), be located at silicon layer (21) silicon oxide outward Layer (23), the metal level (22) being located on silicon oxide layer (23)；Fixing end B(202) silicon layer (21) in be provided with doped silicon layer (24), metal level (22) holds B(202 by the window of silicon oxide layer (23) with fixing) doped silicon layer (24) directly contact composition Ohmic contact；Temperature element (203) is processed by silicon layer (21), and is provided with passivation protection layer at the outer surface of silicon layer (21) (25), outstanding aerial temperature element (203) is by fixing end B(202) be fixed on bearing B(201) on buried regions silicon oxide (12) on, two fixing end B(202) constitute two terminals of the electric pathway of temperature element (203)；

The front of monolithic methane gas detector (2) is parallel relative, after aligned by gold with the front of monolithic high temperature heater (1) The metal bonding belonging to salient point (500) realizes being tightly fastened and electrically connecting of the two；Monolithic methane gas detector (2) after alignment Projection properties on monolithic high temperature heater (1) is: 2 of monolithic methane gas detector (2) fixing end B(202) respectively Fixing end A(106 it is bonded with 2 of monolithic high temperature heater (1)) overlap, the bonding of monolithic methane gas detector (2) supports The support end (105) that end (204) is corresponding with monolithic high temperature heater (1) respectively overlaps, the center of temperature measuring unit (2031) and list The center superposition of the high heating element (1031) of sheet high temperature heater (HTH) (1), the center of the two has identical to respective bearing Distance；Monolithic methane gas detector (2) is fixed by metal salient point (500) metal bonding with monolithic high temperature heater (1) After, the distance range of the distance between the high heating element (1031) of temperature measuring unit (2031) and monolithic high temperature heater (1) Be 3 to 200um；The temperature element (203) of monolithic methane gas detector (2) is by two fixing end B(202), monolithic high temperature Two of heater (1) bonding fixing end A(106) and metal salient point thereon (500) and bonding fixing end A(106) be connected Two electrode leads to client (104) constitute a two-terminal device monolithic high temperature heater (1) is upper, consolidate be bonded described Fixed end A(106) two electrode leads to client (104) enterprising line leads bonding of being connected can realize the connection with external circuit.

2. an application process for the miniature methane transducer encapsulated based on flip chip bonding as claimed in claim 1, makes during use Monolithic methane gas detector (2) is positioned at the lower section of (1) on monolithic high temperature heater, to monolithic methane gas detector (2) with Ambient temperature sensor (3) passes to weak current not to be made temperature element (203) and measures resistance (32) heating；And give monolithic high temperature The high temperature then making heating element heater (103) be heated to more than 500 DEG C after heater (1) energising, enters in current-resistance characteristic curve Working region on the left of turning point；Described turning point is the point of greatest resistance that resistance occurs with curtage increase, works as electricity When stream or voltage continue to increase, resistance does not continues to increase and reduces on the contrary；When not having methane gas, monolithic methane gas detects The temperature element (203) of device (2) is affected temperature by the heating high temperature of heating element heater (103) and is raised, and resistance increases；And work as methane gas When body occurs and when concentration increases, the temperature of heating element heater (103) reduces, and temperature element (203) is affected by temperature also to be reduced, Causing the reduction of self-resistance, the method then passing through electrical detection can detect appearance and the methane concentration change of methane；Ring On the sheet of miniature methane transducer described in border temperature detector (3) standalone probe, temperature is mended for the temperature of methane concentration data Repay.

3. the preparation method of the miniature methane transducer encapsulated based on flip chip bonding as claimed in claim 1, is characterized in that: its bag Include two kinds of preparation methoies:

The monolithic high temperature heater (1) of preparation method (one) first preparative separation and monolithic methane gas detector (2) separated, Described monolithic high temperature heater (1) monolithic methane gas detector (2) uses soi wafer processing, monolithic high temperature heater (1) Can process on same soi wafer when preparing with monolithic methane gas detector (2), or add on different soi wafers Work；Then the monolithic high temperature heater (1) of the separation processed is used upside-down mounting with monolithic methane gas detector (2) separated Sealing dress is prepared as the described miniature methane transducer of overall structure form；

Its concrete preparation process is:

The first step, prepares silicon oxide layer (23) on soi wafer；

Second step, the silicon oxide layer (23) on graphical top layer silicon, form the window needed for doping or ion implanting；

3rd step, doping or ion implanting form doped silicon layer (24)；

4th step, deposits or metal level is prepared in evaporation, and graphical prepared metal forms fixing end B(202), some bondings Support end (204), fixing end A(102), bonding fixing end A(106), support end (105), electrode leads to client (104), electrode tip (1041) metal level (22), and fixing end A(102), bonding fixing end A(106) and electrode leads to client (104) between company Connect metal level；

5th step, is lithographically formed the figure of the etching window of Facad structure, uses RIE(Reactive Ion Etching subsequently, Reactive ion etching) dry etching remove silicon oxide layer (23) that the first step in described etching window figure generates and under Silicon layer (21), etching stopping, in buried regions silicon oxide (12), forms heating element heater (103), fixing end A on buried regions silicon oxide (12) (102), bonding fixing end A(106), electrode leads to client (104), multiple support end (105), measuring cell (102), temperature element (203), fixing end B(202), the structure of bonding support end (204) and ambient temperature sensor (3) and scribe line；

6th step, prepares etch-protecting layer in the front of soi wafer, and described etch-protecting layer covers the front of whole soi wafer；

7th step, is lithographically formed the figure of back-etching window at the soi wafer back side, uses wet etching or ICP (Inductively Coupled Plasma, sense coupling) or DRIE(Deep Reactive Ion Etching, deep reaction ion etching) etc. the bottom silicon of dry etching method etching soi wafer, i.e. substrate (11), etching stopping In buried regions silicon oxide (12)；

8th step, uses the buried regions silicon oxide (12) that hydrofluoric acid solution or Fluohydric acid. aerosol wet etching expose from substrate (11), Discharge heating element heater (103), temperature element (203), discharge heating element heater, temperature element；

9th step, removes the etch-protecting layer that the 6th step is formed；

11st step, uses protective layer to cover the front of soi wafer, and described protective layer covers except heating element heater (103), thermometric unit Soi wafer front portion beyond the measurement resistance (1032) of part (203) hanging structure and ambient temperature sensor (3)；Can Use photoresist as protective layer；Micro-spray printing device can be used to prepare described photoresist after being accurately positioned；It is used as covering Version of sheltering in the front of SOI uses the method for spraying to prepare described photoresist, described in shelter version and only expose except heating element heater (103), temperature element (203) hanging structure and the measurement resistance (1032) of ambient temperature sensor (3), and remaining SOI The masked version of front side of silicon wafer part shelters from；

12nd step, uses ALD Atomic layer deposition method at thermal element (103), temperature element (203) hanging structure and environment The outer surface of the measurement resistance (1032) of temperature detector (3) prepares hafnium oxide, or prepares aluminum oxide film, or preparation oxidation Hafnium/alumina composite thin film, or prepare silicon oxide/hafnium oxide/alumina composite thin film, the oxide thin layer silicon formed with the tenth step Layer collectively forms passivation protection layer (25)；

13rd step, removes protective layer prepared by the 11st step, is dried soi wafer；

14th step, obtains large number of discrete monolithic high temperature heater (1) and discrete monolithic methane gas after scribing, sliver Detector (2)；

15th step, pastes the front of the monolithic high temperature heater (1) prepared with the front of monolithic methane gas detector (2) Close alignment, subsequently by fixing for the bonding of monolithic high temperature heater (1) end A(106), on the metal level (22) of support end (105) Metal coupling (500) and the fixing end B(202 on corresponding monolithic methane gas detector (2)), on bonding support end (204) Metal contact and apply pressure, heating up carries out bonding and forms the described miniature methane sensing of overall laminated construction form Device；

Or preparation method (two) is the wafer level flip chip bonding encapsulation preparation miniature methane transducer described in claim 1, monolithic is high Temperature heater (1) is processed on a SOI silicon wafer, and monolithic methane gas detector (2) adds on another SOI silicon wafer Work；Then the encapsulation of wafer level flip chip bonding is used to be prepared as described miniature methane transducer；

It concretely comprises the following steps:

The first step, prepares silicon oxide layer (23) on soi wafer；

3rd step, doping or ion implanting form doped silicon layer (24)；

4th step, prepares metal, and graphical prepared metal forms fixing end B(202 respectively), some bonding support ends (204), fixing end A(102), bonding fixing end A(106), support end (105), electrode leads to client (104) and electrode tip (1041) On metal level (22) and fixing end A(102), bonding fixing end A(106) golden with the connection between electrode leads to client (104) Belong to layer；

5th step, is lithographically formed the figure of the etching window of Facad structure, uses RIE dry etching to remove described etching window subsequently Silicon oxide layer (23) that the first step in mouthful figure generates and under silicon layer (21), etching stopping in buried regions silicon oxide (12), Buried regions silicon oxide (12) is formed heating element heater (103), fixing end A(102), bonding fixing end A(106), electrode leads to client (104), multiple support ends (105), measuring cell (102), temperature element (203), fixing end B(202), bonding support end (204) with the structure of ambient temperature sensor (3)；

7th step, is lithographically formed the etching window figure of back side scribe line at the back side of SOI silicon wafer, uses RIE to etch SOI silicon The silicon oxide at the sheet back side and bottom silicon, form scribe line；

8th step, is lithographically formed back-etching graph window at the soi wafer back side, uses wet etching or ICP or DRIE(the most anti- Answer ion etching) etc. dry etching method etching soi wafer bottom silicon, i.e. substrate (11), etching stopping is in buried regions silicon oxide (12)；

9th step, uses the buried regions silicon oxide (12) that hydrofluoric acid solution or Fluohydric acid. aerosol wet etching expose from substrate (11), Discharge heating element heater (103), temperature element (203), discharge heating element heater, temperature element；

Tenth step, removes the etch-protecting layer that the 6th step is formed；

12nd step, uses protective layer to cover the front of soi wafer, and described protective layer covers except heating element heater (103), thermometric unit Soi wafer front portion beyond the measurement resistance (1032) of part (203) hanging structure and ambient temperature sensor (3)；Can Use photoresist as protective layer；Micro-spray printing device can be used to prepare described photoresist after being accurately positioned；It is used as covering Version of sheltering in the front of SOI uses the method for spraying to prepare described photoresist, described in shelter version and only expose heating element heater (103), temperature element (203) hanging structure and the measurement resistance (1032) of ambient temperature sensor (3), remaining SOI silicon The masked version in sheet front portion shelters from；

13rd step, uses ALD Atomic layer deposition method at thermal element (103), temperature element (203) hanging structure and environment The outer surface of the measurement resistance (1032) of temperature detector (3) prepares hafnium oxide, or prepares aluminum oxide film, or preparation oxidation Hafnium/alumina composite thin film, or prepare silicon oxide/hafnium oxide/alumina composite thin film, the oxide thin layer formed with the 11st step Silicon layer constitutes passivation protection layer (25) together；

14th step, removes protective layer prepared by the 12nd step, is dried；

The above-mentioned first step to the 14th step is that monolithic high temperature heater (1), monolithic methane gas detector (2) are at respective SOI silicon Procedure of processing on disk；

15th step, has monolithic methane gas health check-up by the front preparing the silicon wafer of monolithic high temperature heater (1) with preparation Survey the front laminating alignment of the silicon wafer of device (2), subsequently by fixing for the bonding of monolithic high temperature heater (1) end A(106), support Metal coupling (500) on the metal level (22) of end (105) fixing end B upper with corresponding monolithic methane gas detector (2) (202), some bonding support ends (204) contact and apply pressure, heating up carries out bonding formation containing monolithic high temperature heater (1) The laminated type silicon wafer that is integrated with silicon wafer containing monolithic methane gas detector (2) of silicon wafer；

16th step, has the scribing on the SOI silicon wafer back side of monolithic methane gas detector (2) along described in the 7th step in preparation Groove scribing, along the thickness of the depth of cut only one of which SOI silicon wafer of scribe line scribing described in this step, gets rid of described preparation Having the silicon of cutting on the SOI silicon wafer of monolithic methane gas detector 2, the electrode exposed on monolithic high temperature heater (1) draws Go out end (104)；

17th step, has the scribe line on the SOI silicon wafer back side of monolithic high temperature heater (1) to draw along described in the 7th step in preparation Sheet；It is the thickness of two SOI silicon wafers along the depth of cut of scribe line scribing described in this step；Sliver obtains described based on falling The miniature methane transducer of welding equipment encapsulation.