CN104391027A

CN104391027A - Preparation method of gas sensor chip

Info

Publication number: CN104391027A
Application number: CN201410644773.3A
Authority: CN
Inventors: 禹胜林
Original assignee: Wuxi Nuist Weather Sensor Network Technology Co Ltd
Current assignee: Wuxi Nuist Weather Sensor Network Technology Co Ltd
Priority date: 2014-11-14
Filing date: 2014-11-14
Publication date: 2015-03-04

Abstract

The invention discloses a preparation method of a gas sensor chip. The preparation method comprises the following steps: arranging a reference gas passage on a first layer of piezoelectric substrate; coating a second layer of piezoelectric substrate with a gas sensitive membrane; firstly plating the surface of a fourth layer of piezoelectric substrate with a bottom electrode, secondly plating the bottom electrode with a semiconductor material thin layer, thirdly coating the semiconductor material thin layer with a disordered metal membrane, and fourthly coating the disordered metal membrane with a point electrode; arranging a reference electrode between the first layer of piezoelectric substrate and the second layer of piezoelectric substrate, and arranging a heating electrode between the second layer of piezoelectric substrate and a third layer of piezoelectric substrate; overlapping the first, second, third and fourth layers of piezoelectric substrates together in order. The preparation method has the beneficial effects that the service life of the chip is prolonged; the yield is increased; the preparation process is simple.

Description

A kind of manufacture method of gas sensor chip

Technical field

The invention belongs to the technical field of sensor chip, in particular to a kind of manufacture method of gas sensor chip.

Background technology

Along with the raising day by day of automobile emission regulation, require also more and more higher to exhaust gas measuring, the cold start-up time that demand of auto engine is shorter for this reason meets the demands.Consider the needs of energy saving simultaneously, the chip oxygen sensor that a kind of integrated level is high, volume is little, consumed power is little, toggle speed is fast becomes a kind of trend, to enter the requirement of closed-loop control after meeting engine electric spray system cold start-up as far as possible fast, reduce the power consumption of lambda sensor simultaneously.

Current existing sheet type sensor structure is primarily of 3 layers of zirconia substrate and some function thick-film layers composition, and zirconia substrate is mainly through curtain coating or to roll the method for film shaping, and thick film functional layer obtains mainly through screen printing technique.The potential electrode of lambda sensor and contrast electrode are formed on the surfaces externally and internally of substrate respectively, the middle part of substrate are washed open one long and narrow openning, to form reference air duct by impact briquetting; And the platinum disposition of heating component of being wrapped up by ceramic insulating layer is on the inside surface of bottom substrate, also to make a call to two through holes at the end of substrate the heating electrode sheet of the heating element of inside surface with outside surface end is coupled together, constitute sensitive element and the integrated chip oxygen sensor structure of heating element.But this structural thickness is thick, volume is large, production process is complicated, and heating element is planted in sensor internal with parcel form, and stability is poor, and easily leaks electricity.

Gas sensor is a kind of converter certain gas volume fraction being changed into corresponding electric signal, current existing gas sensor is of a great variety, by gas sensitive used and gas-sensitive property difference thereof, semiconductor-type, solid electrolyte formula, electric chemical formula, catalytic combustion type etc. can be divided into.

1, semiconductor gas sensor

This sensor accounts for 60% in gas sensor.Resistance-type and non-resistor two kinds can be divided into according to its mechanism.Resistance-type adopts the preparation of the metal oxide materials such as SnO2, ZnO, have porous sintered, thick film, the form such as film.Mainly fixed by the situation of change of the electrical resistance gas content of detection gas sensor, main use metal oxide ceramic gas sensitive.Non-resistor semiconductor gas sensor utilizes the electric current of gas sensor and voltage change with gas content and work.

2, solid-state electrolyte gas sensor

This sensor element is the conduction of ion pair solid electrolyte diaphragm.Its mechanism is the electromotive force utilizing the potential difference (PD) between the battery of two, barrier film both sides to equal concentration cell.Measure gas concentrations is carried out, as the YST-Au-WO3 of H2S can be measured, measure the NH+4CaCO3 etc. of NH3 by measuring electromotive force.

3, catalytic combustion type gas sensor

This gas sensor can be divided into direct catalytic combustion type and catalytic Contact combustion-type two kinds.Its principle of work is: gas sensitive in the energized state, inflammable gas oxidizing fire or under catalyst action oxidizing fire, the heat produced makes the heating wire of sensor heat up, thus its resistance value is changed, and is changed the concentration carrying out measurement gas by measuring resistance.This sensor can only measure inflammable gas, and other are insensitive to non-combustible.

Although current existing gas sensor is of a great variety, principle is different, but the sensor of every type all can only be effective to specific gas, and the selectivity of sensor and the scope of application can not be taken into account, if namely selectivity is good, then detectable gaseous species is few, if detectable gaseous species is many, then selectivity is not high.

Be provide a kind of thin film chip gas sensor in the patented claim of 201410285080.X at number of patent application, comprise one piece of substrate, substrate there is a hearth electrode, substrate and hearth electrode have layer of semiconductor material thin-layer, thin layers of semiconductor material there is one deck unordered type metal film system, fastened point electrode at this unordered type metal film; Described hearth electrode and point electrode are drawn and external impressed current meter by wire; Described structure is placed in the blind boxes of a single radial cut.Also disclose a kind of thin film chip gas sensor preparation method, for the preparation of the sensor chip, prepare one block of backing material, first hearth electrode is plated on the surface of this backing material, plate thin layers of semiconductor material again, be coated with unordered type metal film system again, finally plate point electrode, total is placed in the box closed of a single radial cut; When being applied to detection gas, when gas is by blind boxes, in noble metal system as under the effect of catalyzer, catalyzed chemical reaction occurs, the interface that liberated heat excites the electronics in metal to cross metal and semiconductor forms electric current; Utilize galvanometer sensed current signal, utilize the size of sensed current signal and relatively change the detection realized gas and content thereof.Described substrate is optional the silicon chip of silicon dioxide oxide layer or glass sheet or sheet metal; When selecting substrate process, process substrate, disposal route is corrosion, ion implantation, original position etching and growth Seed Layer.The method of described growth Seed Layer is magnetron sputtering or molecular beam epitaxy or electrochemical deposition.The features such as the thin film chip gas sensor of this application has highly sensitive, and response is fast, and selectivity is good, and structure is simple, and the life-span is long, and can design for any gas, compensate for the shortcoming that traditional gas sensors can be taken into account.

Be provide a kind of integrated chip type oxygen sensor and preparation method thereof in the patented claim of 201010147931.6 at number of patent application, its preparation method comprises the following steps: the first step, by the same PVB of Zirconium oxide powder of 5% moles yttrium, terpinol and dibutyl phthalate (DBP) with 70 ~ 86: 6 ~ 12: 4 ~ 9: 4 ~ 9 quality be prepared into slurry than mixing and ball milling, then by double knife edges technology flow casting molding, zirconia green tape is made after natural drying, substrate base substrate is become again, i.e. upper strata zirconia substrate by mould punching; Then the electrode slurry containing 70% ~ 90% platinum powder and electrocondution slurry are printed on the surfaces externally and internally of upper strata zirconia substrate, form potential electrode and contrast electrode; The Electrode connection through hole that inner surface electrode is formed by upper strata zirconia substrate end punching press is connected with the interior electrode connecting piece (19) of outside surface; Second step, by dag, PVB, terpinol and softening agent with 30 ~ 46: 20 ~ 30: 16 ~ 24: 10 ~ 24 mass ratio mixing fully, formation can screen printing sizing agent, and covers on interior electrode surface by this slurry printing; This reference oxygen diffusion gap printed layers width will between upper strata zirconia substrate and contrast electrode width, and thickness will reach 15 to 50 microns, will form elongate slot after sintering; 3rd step, by the same PVB of Zirconium oxide powder of 5% moles yttrium, terpinol and dibutyl phthalate (DBP) with 70 ~ 86: 6 ~ 12: 4 ~ 9: 4 ~ 9 quality be prepared into slurry than mixing and ball milling, then by double knife edges technology flow casting molding, zirconia green tape is made after natural drying, substrate base substrate is become again, i.e. lower floor's zirconia substrate by mould punching; The slurry of the alumina powder reaching more than 97% containing purity is printed on the outside surface of lower floor's zirconia substrate, prepares alumina ceramic insulating layer; Then the electrocondution slurry containing platinum powder is printed on this alumina ceramic insulating layer, and one-step print forms platinum heating element and heating electrode sheet; 4th step, next, with the bonding agent containing zirconia powder, upper strata zirconia substrate and lower floor's zirconia base flaggy are stacked, be heated to 40 ~ 60 degree press closely simultaneously, again potential electrode end is immersed in the slurry containing magnesium aluminate spinel and lift, form the porous ceramics protective seam of parcel one; 5th step, merges parcel all-in-one-piece green compact 1300 ~ 1500 degree of high temperature sinterings 1 ~ 3 hour, prepares integrated chip type oxygen sensor.

Also there is following deficiency in prior art: complex manufacturing technology, manufacturing process affect the chip life-span, and rejection rate is higher.The Die strength produced by such method does not reach required strength demand, and chip electrode contacts insufficient with measurement gas, impact sensing effect.

Summary of the invention

The present invention is directed to the deficiencies in the prior art, provide a kind of manufacturing process to improve the chip life-span, improve yield rate, the simple sensor chip preparation method of manufacture craft.

For realizing above-mentioned object, have employed following scheme: a kind of manufacture method of gas sensor chip: comprise the following steps:

1) on ground floor piezoelectric substrate, reference gas passage is offered;

2) coating gas sensitive membrane on second layer piezoelectric substrate;

3) first on the surface of the 4th lamination electric substrate, plate hearth electrode, then plate thin layers of semiconductor material, then plate unordered type metal film, and then plate point electrode;

4) contrast electrode is arranged between ground floor piezoelectric substrate and second layer piezoelectric substrate, heating electrode is arranged between second layer piezoelectric substrate and third layer piezoelectric substrate;

5) ground floor piezoelectric substrate is overlapped together in turn to the 4th lamination electric substrate.

Further, magnetron sputtering method is adopted to plate hearth electrode on piezoelectric substrate.

Further, sol-gal process or molecular beam epitaxy or electrochemical deposition is adopted to prepare semiconductor film material thin-layer.

Further, the thickness of described gas sensitization film is 120-200 nanometer.

Further, the material of described piezoelectric substrate is zirconia.

Beneficial effect of the present invention:

The features such as the present invention is provided with the reference channel being exclusively used in and detecting gas, has highly sensitive, and response is fast, and selectivity is good, and structure is simple, and the life-span is long, and can design for any gas, compensate for the shortcoming that traditional gas sensors can be taken into account.This manufacturing process improves the chip life-span, it is simple to improve yield rate, manufacture craft.

Embodiment

For making the object of the embodiment of the present invention and technical scheme clearly, the technical scheme below in conjunction with embodiment is clearly and completely described.Obviously, described embodiment is a part of embodiment of the present invention, instead of whole embodiments.Based on described embodiments of the invention, the every other embodiment that those of ordinary skill in the art obtain under without the need to the prerequisite of creative work, all belongs to the scope of protection of the invention.

Those skilled in the art of the present technique are appreciated that unless otherwise defined, and all terms used herein (comprising technical term and scientific terminology) have the meaning identical with the general understanding of the those of ordinary skill in field belonging to the present invention.Should also be understood that those terms defined in such as general dictionary should be understood to have the meaning consistent with the meaning in the context of prior art, unless and define as here, can not explain by idealized or too formal implication.

Embodiment 1

A kind of gas sensor chip, by ground floor to the 4th layer totally four lamination electric substrates be overrided to form, wherein,

Described ground floor piezoelectric substrate is provided with reference gas passage;

Be provided with contrast electrode between described ground floor piezoelectric substrate and second layer piezoelectric substrate, described reference gas passage is connected with described contrast electrode;

Be provided with heating electrode between described second layer piezoelectric substrate and third layer piezoelectric substrate, described second layer piezoelectric substrate is coated with gas sensitization film, described sensitive membrane is the polymer film corresponding gas to adsorption and desorption performance;

Described 4th lamination electric substrate is arranged the unordered type metal film of one deck, and on this unordered type metal film set-point electrode.

The manufacture method of this gas sensor chip: comprise the following steps:

1) on ground floor piezoelectric substrate, reference gas passage is offered;

2) coating gas sensitive membrane on second layer piezoelectric substrate, its thickness is 160 nanometers;

3) first on the surface of the 4th lamination electric substrate, plate hearth electrode, then adopt sol-gal process to plate thin layers of semiconductor material, then plate unordered type metal film, and then plate point electrode;

Embodiment 2

Described ground floor piezoelectric substrate is provided with reference gas passage; The material of described piezoelectric substrate is zirconia;

Be provided with contrast electrode between described ground floor piezoelectric substrate and second layer piezoelectric substrate, described reference gas passage is connected with described contrast electrode, and described contrast electrode is coated with porous alumina layer, and described reference gas passage is communicated with porous alumina layer;

Described heating electrode respectively have a layer insulating up and down.The upper and lower insulation course material of described heating electrode is compact aluminum oxide matter.

The manufacture method of this gas sensor chip: comprise the following steps:

1) on ground floor piezoelectric substrate, reference gas passage is offered;

2) coating gas sensitive membrane on second layer piezoelectric substrate, its thickness is 200 nanometers;

3) first adopt magnetron sputtering method to plate hearth electrode on the surface of the 4th lamination electric substrate, then adopt molecular beam epitaxy to plate thin layers of semiconductor material, then plate unordered type metal film, and then plate point electrode;

These are only embodiments of the present invention, it describes comparatively concrete and detailed, but therefore can not be interpreted as the restriction to the scope of the claims of the present invention.It should be pointed out that for the person of ordinary skill of the art, without departing from the inventive concept of the premise, can also make some distortion and improvement, these all belong to protection scope of the present invention.

Claims

1. the manufacture method of a gas sensor chip: it is characterized in that, comprise the following steps:

Ground floor piezoelectric substrate is offered reference gas passage;

Coating gas sensitive membrane on second layer piezoelectric substrate;

First on the surface of the 4th lamination electric substrate, plate hearth electrode, then plate thin layers of semiconductor material, then plate unordered type metal film, and then plate point electrode;

Contrast electrode is arranged between ground floor piezoelectric substrate and second layer piezoelectric substrate, heating electrode is arranged between second layer piezoelectric substrate and third layer piezoelectric substrate;

Ground floor piezoelectric substrate is overlapped together in turn to the 4th lamination electric substrate.

2. the manufacture method of a kind of gas sensor chip according to claim 1, is characterized in that, adopts magnetron sputtering method to plate hearth electrode on piezoelectric substrate.

3. the manufacture method of a kind of gas sensor chip according to claim 1, is characterized in that, adopts sol-gal process or molecular beam epitaxy or electrochemical deposition to prepare semiconductor film material thin-layer.

4. the manufacture method of a kind of gas sensor chip according to claim 1, is characterized in that, the thickness of described gas sensitization film is 120-200 nanometer.

5. the manufacture method of a kind of gas sensor chip according to claim 1, is characterized in that, the material of described piezoelectric substrate is zirconia.