Summary of the invention
The objective of the invention is to overcome the deficiencies in the prior art, a kind of pressure switch based on the MEMS technology is provided, it is simple in structure, high conformity, with low cost, simple in structure, be easy to integrate with subsequent conditioning circuit, carry out signal condition, conversion and networking; Applied widely.
According to technical scheme provided by the invention, described pressure switch based on the MEMS technology comprises base and is positioned at pipe cap on the base; Described pipe cap is provided with the impulse mouth corresponding to the other end that links to each other with base; Base is provided with groove corresponding to the end of contiguous pipe cap, and the other end of base is provided with cable aperture, and described cable aperture all is connected with groove, impulse mouth; Be provided with cable in the cable aperture; Be provided with adapter assembly in the described groove, described adapter assembly is provided with sensing assembly; Described adapter assembly comprises supporter, and the center of described supporter is provided with down pod apertures, and supporter is provided with conductive pole; Described sensing assembly comprises solid support body and is positioned at the described silicon chip of consolidating on the support body; Described silicon chip is provided with metal level corresponding to the other end surface that links to each other with solid support body, and silicon chip is concaved with elastic groove corresponding to the end of contiguous solid support body, forms boss between described elastic groove, and described boss is provided with top electrode; Gu the center of support body is provided with pod apertures, last pod apertures is connected with following pod apertures; Gu the surface at support body two ends reaches the inwall of going up pod apertures and forms bottom electrode; Described bottom electrode and metal level are electrically connected by conductive pole corresponding on lead and the supporter respectively; Conductive pole corresponding is connected the lead electrical connection respectively with in the cable corresponding to the other end that links to each other with lead.
Described base is provided with securing member corresponding to the end that cable aperture is set; After one end of cable passes securing member, be fastened and connected with securing member.Be provided with sealing ring in the described securing member, described sealing ring is enclosed within on the cable.Described supporter is provided with the conduction cladding plate corresponding to the end that links to each other with silicon chip, is provided with insulator between described conduction cladding plate and conductive pole; Gu support body is electrically connected corresponding to end that bottom electrode is set and conduction cladding plate; Bottom electrode is electrically connected with corresponding conductive pole by conduction cladding plate and lead.Be provided with wireway in the described cable, an end of described wireway is positioned at groove, and is connected with last pod apertures and following pod apertures.
The inner peripheral surface of described groove is provided with some solid Zhi Taijie, and described adapter assembly is installed on the solid Zhi Taijie of groove.Described silicon chip is the n type single crystal silicon sheet.Described solid support body is PYREX glass or monocrystalline silicon.The material of described metal level is aluminium, copper, gold or silver-colored; Described metal level evaporation is on silicon chip.
Advantage of the present invention: sensing assembly comprises silicon chip, and silicon chip adopts the MEMS technology to form elastic groove and top electrode, forms E type flexible sheet, can make things convenient for and carry out integrated with subsequent conditioning circuit; Clearance height corresponding matching between the thickness of flexible sheet and top electrode and bottom electrode has determined the rated operating pressure of pressure switch.Air-flow enters from the impulse mouth, and Pneumatic pipe cleaner is crossed metal level and acted on the silicon elastic groove, by the effect of cooperatively interacting of top electrode and bottom electrode, and outwards exports by the connection lead in the cable, finishes switching function, and is easy to use.There are not movable relatively parts, reliable operation, long service life in the sensing assembly.The pressure switch volume is little, helps making microminiaturization, and miniaturization or face paste the formula device, and sensing assembly adopts the manufacturing of MEMS technology, can produce in enormous quantities, reduces production costs, and is applicable to every field.
Embodiment
The invention will be further described below in conjunction with concrete drawings and Examples.
As Fig. 1~shown in Figure 5: the present invention includes sensing assembly 1, adapter assembly 2, base 3, securing member 4, sealing ring 5, cable 6, pipe cap 7, lead 8, impulse mouth 9, connector 10, silicon chip 11, metal level 12, spring beam 13, top electrode 14, electrode gap 15, bottom electrode 16, Gu support body 17, last pod apertures 18, elastic groove 19, boss 20, following pod apertures 21, insulator 22, conduction cladding plate 23, supporter 24, conductive pole 25, installing hole 26, groove 27, Gu Zhi Taijie 28, cable aperture 29, binding thread 30, connect lead 31 and wireway 32.
As shown in Figure 1: described base 3 is provided with fixedly connected pipe cap 7, and 7 of described base 3 and pipe caps form cavity structure.Pipe cap 7 is provided with connector 10 corresponding to the other end that links to each other with base 3, described connector 10 is positioned at the center of pipe cap 7, be provided with impulse mouth 9 in the connector 10, described impulse mouth 9 extends in the pipe cap 7 from the surface of connector 10, and impulse mouth 9 is connected with the cavity that base 3 and pipe cap 7 form.The structure of base 3, as shown in Figure 4.Described base 3 is provided with groove 27 corresponding to the end with contiguous pipe cap 7, and base 3 is provided with step corresponding to the other end away from groove 27; Base 3 is provided with the contiguous block of vertical distribution corresponding to the center that step is set, and is provided with cable aperture 29 in the described contiguous block, and described cable aperture 29 is connected with groove 27.Some steps are set on the inner peripheral surface of described groove 27, form solid Zhi Taijie 28.On the described solid Zhi Taijie 28 fixedly connected adapter assembly 2 is installed, described adapter assembly 2 is provided with sensing assembly 1.
As shown in Figure 2: be the structural representation of sensing assembly 1 of the present invention.Described sensing assembly 1 comprises solid support body 17, and described solid support body 17 is provided with silicon chip 11.Described silicon chip 11 is a n type single crystal silicon; Silicon chip 11 is provided with metal level 12 corresponding to the surface of the other end that links to each other with solid support body 17, and described metal level 12 is close to impulse mouths 9, and is positioned at the below of impulse mouth 9.The material of described metal level 12 can be aluminium, copper, gold or silver-colored, but preferably adopts multiple layer metal, as nickel-chromium-Jin, platinum-titanium-Jin, nickel-copper-Jin or chromium-nickel-Yin.Described metal level 12 by evaporation on silicon chip 11.Silicon chip 11 is provided with elastic groove 19 corresponding to the end that links to each other with solid support body 17, and described elastic groove 19 extends upward 19 formation boss 20 of elastic groove from silicon chip 11 corresponding to the surface that links to each other with solid support body 17; Described boss 20 and elastic groove 19 corresponding cooperations make silicon chip 11 form the flexible sheet with E type structure.Described boss 20 is provided with top electrode 14, and the silicon chip 11 of described elastic groove 19 top correspondences forms spring beam 13.Silicon chip 11 forms cavity structure corresponding to the bottom that elastic groove 19 is set.Gu the center of support body 17 is provided with pod apertures 18, Gu reaching to go up in the pod apertures 18, two end faces of support body 17 all are deposited with lower electrode material, Gu the lower electrode material of support body 17 both ends of the surface is electrically connected by the lower electrode material in the last pod apertures 18, form bottom electrode 16.Gu support body 17 is corresponding with the shape of top electrode 14 corresponding to the bottom electrode 16 of contiguous boss 20; Gu 14 of bottom electrode 16 on the support body 17 and top electrodes have electrode gap 15; Be full of air in the described electrode gap 15.
Silicon chip 11 is the monocrystalline silicon of N type high-concentration dopant, has extremely low resistivity.The thickness of
silicon chip 11 is 200~1000 μ m; And
silicon chip 11 carried out twin polishing.The thermal oxidation silicon layer of
silicon chip 11 superficial growth one decks 0.5~1 μ m after polishing, deposit one layer thickness is on described thermal oxidation silicon layer again
Silicon nitride layer, form hard mask between described thermal oxidation silicon and silicon nitride layer.By shelter etching hard mask layer optionally, on
silicon chip 11, obtain
elastic groove 19 and
boss 20 structures, thereby make
silicon chip 11 form flexible sheet with E type structure.The cross section of described
boss 20 can be for square or circular, and the lateral length of
boss 20 is 500~2000 μ m.During etching, the silicon nitride of first etching
elastic groove 19 and
boss 20 belows, the silica on etching
elastic groove 19 then.The etching depth of described
elastic groove 19 is c, and then the silica of
etching boss 20 belows, last again the
silicon chip 11 of
elastic groove 19 and
boss 20 belows is carried out deep etching, and described etching depth is d, and described etching depth d is by the measuring range decision of pressure switch; Remaining silica and silicon nitride on the corrosion of
silicon 11 more at last, the degree of depth of described etching depth d and
elastic groove 19 parts has determined the rated operating pressure of pressure switch, the i.e. measurement range of pressure switch.At last, on away from the surface of consolidating
support body 17 and
boss 20, form metal layer, form
metal level 12 and
top electrode 14 respectively at
silicon chip 11.
Gu support body 17 can also can be monocrystalline silicon for PYREX glass (Pyrex), on two surfaces of described solid support body 17, form metal layer by evaporation coating method, solid support body 17 is carried out etching corresponding to the metal layer of the end face that links to each other with silicon chip 11, etch away solid support body 17 metal layer partly that links to each other with silicon chip 11; And the method for passing through burn into laser drilling or ultrasonic punching in the center of solid support body 17 is made pod apertures 18, then by plating hole technology, metal lining layer in last pod apertures 18 is electrically connected the metal layer at solid support body 17 two ends, thereby forms bottom electrode 16 structures.Gu support body 17 is corresponding corresponding to the shape of bottom electrode 16 shapes of the end faces that link to each other with silicon chip 11 and top electrode 14.
When solid support body 17 is PYREX glass,, silicon chip 11 is fixed on the solid support body 17 Gu 11 of support body 17 and silicon chips pass through electrostatic bonding.When solid support body 17 is monocrystalline silicon,, become sensing assembly 1 Gu 11 of support body 17 and silicon chips close by silicon-silicon bond or gold-silicon bonding is fixed on silicon chip 11 on the solid support body 17.
As shown in Figure 3: described adapter assembly 2 comprises supporter 24, and the center of described supporter 24 is provided with down pod apertures 21.Supporter 24 is provided with installing hole 26 corresponding to the outer ring that pod apertures 21 is set down, and described installing hole 26 is two.For the ease of connecting, on the surface of supporter 24, be provided with conduction cladding plate 23, described conduction cladding plate 23 can be copper cladding plate or other metal level cladding plates.When supporter 24 was provided with conduction cladding plate 23, following pod apertures 21 extended to the surface of supporter 24 other ends from the surface of conduction cladding plate 23; Described installing hole 26 also extends to the surface of supporter 24 other ends from the surface of conduction cladding plate 23.Be provided with conductive pole 25 in the described installing hole 26, stretch out respectively outside the installing hole 26 at the two ends of described conductive pole 25. Conductive pole 25 and 23 of cladding plates of conduction are provided with insulator 22, and described insulator 22 is positioned at installing hole 26.Supporter 24 can also can be made for firm nonmetallic materials for metal.Sintering has the conductive pole 25 of mutually insulated on supporter 24, and conduction cladding plate 23 is bonded on the supporter 24.
Described solid support body 17 is fixed on supporter 24 corresponding on the surface that conduction cladding plate 23 is set, Gu the last pod apertures 18 on the support body 17 is connected with following pod apertures 21 on the supporter 24.Gu support body 17 corresponding to the surface that bottom electrode 16 is set by conducting resinl bonding or welding the method bonding or be welded on the conduction cladding plate 23.Gu the bottom electrode 16 of support body 17 ends is electrically connected with conduction cladding plate 23.Supporter 24 is fixed on the solid Zhi Taijie 28 in the base 3 corresponding to the other end that conduction cladding plate 23 is set, and the end of described conductive pole 25 is positioned at groove 27.A conductive pole 25 on the described supporter 24 is electrically connected by lead 8 and metal level 12; For another conductive pole 25 on the supporter 24 is electrically connected with bottom electrode 16, earlier conductive pole 25 is electrically connected by the conduction cladding plate 23 of lead 8 with conductive pole 25 1 sides.Because conduction cladding plate 23 is to be electrically connected with bottom electrode 16, thus conductive pole 25 with conduct electricity after cladding plate 23 is electrically connected, can reach being electrically connected of conductive pole 25 and bottom electrode 16.
As shown in Figure 4 and Figure 5: be provided with cable 6 in the described cable aperture 29, comprise in the cable 6 that two connect lead 31.The connection lead 31 of cable 6 one ends is continuous with corresponding conductive pole 25 respectively, and the other end of cable 6 passes cable aperture 29.Base 3 also is provided with securing member 4 corresponding to the end that cable aperture 29 is set, and is provided with sealing ring 5 in the described securing member 4; Described sealing ring 5 and securing member 4 are enclosed within on the cable 6.3 of securing member 4 and bases are by welding or thread connection, and cable 6 is fastened and connected with base 3 by securing member 4 and sealing ring 5, and can guarantee the sealing property of 7 of base 3 and pipe caps.When measuring the air pressure of little range, in order to improve certainty of measurement, in cable 6, establish wireway 32 can be set, described wireway 32 and groove 27, down pod apertures 21 and on pod apertures 18 all be connected.Described base 3 also is provided with binding thread 30 corresponding to the end that cable aperture 29 is set, and is convenient to securing member 4 and carries out screw threads for fastening with base 3 and be connected.
As described in Fig. 1~Fig. 5: during use, that the other end of cable 6 connecting lead wires 31 is continuous with corresponding link respectively.During work, air-flow enters from impulse mouth 9 and since metal level 12 be positioned at impulse mouth 9 under; After air-flow entered the cavity of pipe cap 7 and 3 formation of base from impulse mouth 9, air-flow can produce pressure to metal level 12.Silicon chip 11 is highly doped n type single crystal silicon, and resistivity is low, so metal level 12 has the electromotive force that equates with top electrode 14.12 of elastic groove 19 and metal levels form spring beam 13, and when air pressure produced pressure to metal level 12, spring beam 13 can produce deformation, and described top electrode 14 has corresponding variation with the electrode gap 15 of 16 of bottom electrodes.When the pressure of the air-flow that enters from impulse mouth 9 equaled the rated value of pressure switch greater than fire, described top electrode 14 and bottom electrode 16 pitch smaller can outwards be exported corresponding signal until producing electric contact.Top electrode 14 is continuous with corresponding conductive pole 25 by metal level 12, lead 8, bottom electrode 16 is continuous with corresponding conductive pole 25 by conduction cladding plate 23, lead 8, therefore the variation of 16 of top electrode 14 and bottom electrodes, can outwards export corresponding signal by conductive pole 25 and cable 6, thereby make the pressure switch conducting.When top electrode 14 moved downward under by the effect of measuring pressure, the gas in the electrode gap 15 can be discharged into the outside by last pod apertures 18, following pod apertures 21 and wireway 32, can not move downward the generation resistance to top electrode 14.To the wide range pressure switch, wireway 32 is not set in cable 6, the outside resistance that is produced that can not be discharged into by the body of calming the anger in the electrode gap 15 will be much smaller than by measuring pressure, and its influence can be ignored.The structure that forms elastic groove 19 and boss 20 on the described silicon chip 11 adopts the MEMS technology, and is easy to operate.By the different etching depth of elastic groove 19 is set, can access different spring beam 13, thereby can access the working range of different pressure switches.
Sensing assembly 1 of the present invention comprises silicon chip 11, and silicon chip 11 adopts the MEMS technology to form elastic groove 19 and top electrode 14, forms E type flexible sheet, can make things convenient for and carry out integrated with subsequent conditioning circuit; The clearance height corresponding matching that the thickness of flexible sheet and top electrode 14 and bottom electrode are 16 has determined the rated operating pressure of pressure switch, and measuring range is wide, and the highest measurement range can reach 80MPa.Air-flow enters from impulse mouth 9, and gas pressure by the cooperatively interact effect of top electrode 14 with bottom electrode 16, and passes through cable 6 interior connection leads 31 and outwards exports on metal level 12, changes the on off state of pressure switch, and is easy to use.There are not movable relatively parts, reliable operation, long service life in the sensing assembly 1.The pressure switch volume is little, helps making microminiaturization, and miniaturization or face paste the formula device, sensing assembly adopts the manufacturing of MEMS technology, can produce in enormous quantities, reduce production costs, go in the fields such as industry, agricultural, scientific research, building, Aero-Space and military affairs.Simple in structure, high conformity, with low cost, be easy to integrate with subsequent conditioning circuit, carry out signal condition, conversion and networking.