+

WO1998011279A1 - Deposition d'un film polymere mince electroconducteur d'une resistance desiree, utilisable dans le domaine de la detection des gaz - Google Patents

Deposition d'un film polymere mince electroconducteur d'une resistance desiree, utilisable dans le domaine de la detection des gaz Download PDF

Info

Publication number
WO1998011279A1
WO1998011279A1 PCT/NZ1997/000123 NZ9700123W WO9811279A1 WO 1998011279 A1 WO1998011279 A1 WO 1998011279A1 NZ 9700123 W NZ9700123 W NZ 9700123W WO 9811279 A1 WO9811279 A1 WO 9811279A1
Authority
WO
WIPO (PCT)
Prior art keywords
resistance
deposition
film
current
measurement
Prior art date
Application number
PCT/NZ1997/000123
Other languages
English (en)
Inventor
Ashton Cyril Partridge
Paul David Harris
Michael Kenneth Andrews
Original Assignee
Industrial Research Limited
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Industrial Research Limited filed Critical Industrial Research Limited
Priority to AU44044/97A priority Critical patent/AU733671B2/en
Priority to EP97942321A priority patent/EP0931183A4/fr
Publication of WO1998011279A1 publication Critical patent/WO1998011279A1/fr

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
    • C25D13/00—Electrophoretic coating characterised by the process
    • C25D13/12—Electrophoretic coating characterised by the process characterised by the article coated
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
    • C25D13/00—Electrophoretic coating characterised by the process
    • C25D13/18—Electrophoretic coating characterised by the process using modulated, pulsed, or reversing current
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01C—RESISTORS
    • H01C17/00—Apparatus or processes specially adapted for manufacturing resistors
    • H01C17/22—Apparatus or processes specially adapted for manufacturing resistors adapted for trimming

Definitions

  • the invention comprises a method and apparatus for depositing conducting polymers iilms lor use in gas sensing applications and an apparatus for measuring resistance changes in thin conducting polymer films and gas sensing applications
  • a considerable difficulty in the technology is the production of films of repeatable electrical characteristics, in a form which maximises their chemical sensitivity. It is desirable that the film between the electrodes is as uniform as possible, and two basic methods are in use to achieve this; electrodeposition directly from solution, or chemical deposition of a base polymer film, followed by its patterning by lithographic techniques to provide a controlled geometry on which to electrodeposit the sensing polymer.
  • the measurement oi film resistance is complicated by the fact that frequently very small changes to a large resistance need to be measured; further, thin films heat very readily and change their resistance unless the measuring power is small.
  • the invention provides a method which enables a thin polymer film of controlled resistance to be deposited on a microelectrode array to form a resistance probe, and a method for operating such a gas sensing array in which the effect of self heating of the film can be minimised or avoided and inherent 1/f sensor noise minimised.
  • the invention comprises a method for depositing a gas sensing polymer film, in which the resistance of the depositing polymer film is measured during the deposition process. This can be done in a time-multiplexed fashion in which an electrodepositing current pulse is applied to the electrodes followed by a period in which the inter-electrode resistance is measured using a voltage below the threshold at which electrodeposition occurs Alternatively an ac method capable of measuring high impedance at low voltages may be employed, and the measurement of resistance can then be carried out simultaneously with the deposition Thin films may be grown reliably to high resistances, or thicker films can be grown to predetermined resistance values, using the method of the invention.
  • the direct electrodeposition is onto a microelectrode array in which the element spacing is of the order of ten microns, more or less.
  • Microelectrodes are desirable because they enable more uniform films to be deposited; techniques which require a film to be grown many microns across a gap, between for example the ends of wires embedded in epoxy, tend to be very thick and non-uniform.
  • Polymers such as polypyrrole form first by an electrode reaction which produces an oligomer in the solution surrounding the electrode; the oligomers then diffuse in the solution a distance before settling onto a surface and completing their polymerisation From likely diffusion coefficients in solution, and because diffusion proceeds as the square root of time, the characteristic diffusion distance de distance in which the concentration falls by perhaps a factor of three) is expected to be a lew tens of microns. Diffusion over larger distances will take much larger times and will likely be destroyed by convection. The implication is that in order to achieve maximum uniformity of deposition thickness in the gap between two electrodes, the gap should not exceed this diffusion length.
  • the microelectrode pattern comprises four parallel gold tracks on the surface of an insulator such as layer of silicon dioxide on top of a silicon chip for example.
  • Each electrode may be of the order of 1 OOOum long and several microns wide, separated from its neighbour by a similar distance.
  • the methods described will apply to manv similar structures.
  • the invention comprises a method whereby the resistance of a number of polymer film sensors of different kinds, exposed to a vapour, can be measured using powers low enough that self heating of the film (with consequent resistance changes) does not occur. Since it is generally the change of resistance which is required, and this is usually a small fraction of the total resistance, a stable and accurate method of offsetting using ac techniques is used.
  • the resistance of polymer films is a strong function of temperature. We have found for example that the temperature coefficient is in the region of 2% per degree. We have also found that measuring powers of a milliwatt are sufficient to cause noticeable rises in film temperature. To achieve the maximum sensitivity to target gases de to be confident that resistance changes represent gas responses and not changes due to measurement artefacts) it is desirable to use the lowest power possible.
  • the measured resistance of the polymer films consists of two parts, a pair of contact resistances between the polymer and the metal (usually gold) electrodes, in addition to the true film resistance between the electrodes. Measurements show that the contact resistance can be a significant component of the total resistance measured.
  • this contact resistance may or may not be modulated along with the bulk resistivity of the polymer upon exposure to target gases, but in the examples we have examined the modulation is always considerably less than the modulation of the bulk resistivity.
  • a two-terminal measurement of the resistance change will thereiore exhibit less sensitivity than a method which probes bulk resistivity of the polymer.
  • Measurements representative of bulk resistivity can be made by the four point probe, a technique used in other disciplines, in which two electrodes are used to inject a current, and the voltage drop between two other electrodes is measured at near-zero current to eliminate the contact impedance at those terminals.
  • the preferred method of measuring film resistance in a way which maximises sensitivity therefore is to use a low voltage ac technique in conjunction with a four point probe, but the electrical measurement can be performed on a two electrode probe. Sensitivity increases of the order of 50% have been measured using a four point method compared with a two point method.
  • a further advantage of the use of ac techniques is that the inherent 1/f sensor noise is circumvented.
  • Figure 1 schematically illustrates the deposition of a thin polymer film on a microelectrode sensor array using the method of the invention
  • Figure 2 shows examples including current and measured resistance wave forms using the system of Figure 1 ,
  • Figure 3 shows a dc bootstrap circuit that may be used in a system for depositing polymer film by the method of the invention
  • Figure 4 is a block diagram of a preferred form synchronous measuring system
  • Figure 5 shows examples of waveforms frequency applied voltage current and a mask for the measuring system of Figure 4,
  • Figure 6 shows a preferred form gas sensing system of the invention.
  • Conducting polymers are typically by electrodeposition from a solution.
  • polypyrrole may be deposited by applying a potential of between 750 and 900mV (relative to a Ag/AgCl reference) to the electrode upon which deposition is sought in a solution of 0.1 M pyrrole and an appropriate dopant ion salt (0.1 M), using a counter electrode to supply the required current in a either a potentiostatic or galvanostatic mode.
  • a potential of between 750 and 900mV relative to a Ag/AgCl reference
  • 0.1 M dopant ion salt
  • Figure 1 illustrates the method using a four-terminal probe.
  • Figure 2 shows waveforms for current applied, excitation of relay RE. and measured resistance. Initially, relay RE ties together all electrodes. The deposition controller 1 then applies either a current pulse via the auxiliary mode. A typical pulse duration is 2 sec. Relay RE is then released and the resistance measuring circuit then operates in two-terminal mode applying a measuring voltage between and seeking a contact between the outer electrodes of the sensor electrode array 4 via a deposited film. Two terminal configuration is achieved using the solid state switches 5. If the applied voltage V is nominally lOmV, the actual voltage V means appearing across the electrodes, which is measured for the calculation of resistance may be less, depending upon whether a two or four terminal measurement is operating. The current is detected using a sensing resistor (E). The film resistance is calculated irom the voltage to current ratio, with maximum measurable value in excess of one megohm.
  • E sensing resistor
  • the function of the series resistors R s is to ensure that deposition current is shared equally between the four electrode tracks. Should one track, for whatever reason, draw more current than the others, its series resistance R s causes a reduction of the deposition voltage at the metal-liquid interface, and in so doing, reduces the electrochemical current.
  • the application of current pulses to deposit the film on sensor electrode array 4 and intermediate resistance measurements is continued, and after a small number of such deposit and measure cycles, the resistance is observed to fall to within the measuring range, indicating the presence of a continuous conducting film over and between the electrodes. During measure phases, with no deposition current) the resistance is seen to fall somewhat as ohgomers formed during the previous deposition pulse settle and polymerise on the film.
  • the relay RE may be opened and (wo or four terminal resistance measurement performed. This is possible because the resistance measurement is done at ac, while the deposition is a dc process Precautions are taken however to ensure that the return path for the deposit current del cannot be through the ac voltage generator. This is achieved by the dc bootstrap shown in Figure 3.
  • Amplifier 7 and integrator 8 detect any dc current through the current sensing resistor 5, and applies a correction via the waveform generator 6. No dc can then flow through resistance 5, which appears like an infinite impedance to deposition currants.
  • the current path through the solution has a large capacitive component at the electrode-liquid boundary. This component is frequency dependent, and therefore provides the least shunting effect if the measurement is confined to low frequencies. It is necessary to keep measuring voltages at a level well below that at which electrodeposition could be affected; currents arising from electroactive species in the solution would in any case appear as a resistive shunt across the desired film resistance and cause measurement errors.
  • the measuring voltage level is of the order of l OmV. Special synchronous electronic techniques are necessary to measure accurately impedances of the order of a megohm with such low level signals.
  • Figure 4 is a block diagram of a preferred form synchronous measuring system.
  • Figure 5 shows waveforms for frequency, applied voltage, current, and a mask. Square wave voltages (line C) are generated from a crystal and applied to the electrodes. Because of the capacitive sheath surrounding the electrodes, currants 1+ and I- (line B ) are generated. In an experimental system the capacitive component had substantially decayed after 5msec. A measuring frequency of 50Hz therelore gave times of 5msec in both half cycles during which the current and voltages are approximately constant and both are ultimately averaged over these times using a mask
  • V, V-, I+, I- are now average values of the respective quantities, found by simply counting periods over their non-masked intervals. Sixteen bit resolution with excellent linearity is achieved.
  • the measurement of film resistance during deposition enables various phases of film growth to be established, and deposition stopped at an appropriate position. In general, immediately following bridging of the gaps, the conductance rises to reach a maximum rate of change with time. Microscopic inspection shows this period correlates with the initial growths spreading between tracks and coalescing into a more-or-less uniform film. The film conductance now enters a period of more l ⁇ ne ⁇ r growth with time as the film thickens, which finally reduces to raies corresponding lo very thick films. Growth may be stopped at any appropriate stage, thin films generally exhibit greater chemical sensitivity.
  • Figure 6 shows a system employing a thin conducting gas sensitive polymer film. The circumstances of measuring the resistance of the deposited films in air differs from their measurement during deposition because
  • the measurement can be made at frequencies up to at least 100kHz since the film is resistive and is not shunted by the reactive impedance of the solution as it was during film deposition.
  • the measurement is performed as described in the following. Provision is made for multiple measurements with one ac current source, for example at a frequency of 1 kHz, and provision is also made for ranging and offset by subtracting synchronous ac currents and amplifying residual signals prior to detection.
  • a measuring current of between 1 and l OOuA is injected to the outer terminals of a four terminal probe This current is chained through a number of other probes, for example eight.
  • the different voltage appearing across the inner electrodes is sensed This differential voltage may be offset by a programmable amplitude signal at the same frequency, and amplified, before synchronous detection and low pass filtering.
  • the programmable offset and scale may be set so that the individual sensor response best suits the A-D converter range.
  • an octal converter can monitor eight channels simultaneously.
  • a local microprocessor is used to perform further digital filtering before outputting the data to a computer.
  • the contact resistance has been measured to be as much as 50% of the film resistance. It has been found to exhibit some gas sensitivity, but alwavs less as a percentage than the film resistance.
  • Table 1 shows the measured film and contact resistances in nitrogen for five sensors, and the percentage improvement in sensitivity upon exposure to ethanol vapour when measured in four terminal mode compared with two terminal.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Manufacturing & Machinery (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Investigating Or Analyzing Materials By The Use Of Fluid Adsorption Or Reactions (AREA)

Abstract

L'électrodéposition sur des microélectrodes de polymères minces capteurs, dont le développement s'est apparemment fait selon les mêmes paramètres, donne lieu à d'importants écarts en matière de résistance. Des films de plus grande épaisseur et d'une résistance plus conséquente, ont un délai de réponse trop long du fait du temps que met le gaz cible à s'y diffuser. On peut supprimer ces inconvénients par une adaptation de minces films polymères électroconducteurs à la résistance désirée et ce, en évaluant la résistance, à intervalles donnés dans le temps, durant le processus de déposition tout en poursuivant la déposition du film jusqu'à l'obtention d'une résistance d'une valeur élevée ou prédéterminée. On arrive à un un tel résultat en utilisant un mode opératoire de multiplexage temporel, mode selon lequel une impulsion de courant d'électrodéposition est appliquée aux électrodes, laquelle impulsion est suivie d'un laps de temps pendant lequel l'inter-électrode est mesuré au moyen d'une tension inférieure au seuil de survenue de l'électrodéposition. Selon une variante, il est possible de mettre en oeuvre un procédé à courant alternatif, permettant de mesurer une impédance élevée à basses tensions et donc, de mesurer les valeurs de la résistance en même temps que s'effectue l'électrodéposition. Le polypyrrole, qui peut être déposé à un potentiel compris entre 750 et 900 millivolts est, à cet égard, un polymère électroconducteur des plus représentatif. Le pyrrole forme un oligomère à partir d'une solution avant que ne s'effectuent in situ la déposition et la polymérisation. Le substrat est, de préférence, un réseau de microélectrodes, pouvu d'éléments d'une longueur de 1000 ν, d'une largeur de plusieurs ν et séparés par 10 ν (c'est-à-dire, à l'intérieur de la plage dans laquelle la concentration décroît selon un facteur d'une valeur s'élevant à 3). La présence d'une contre-électrode permettant l'alimentation en courant, qu'il s'agisse d'un mode potentiostatique ou galvanostatique, est également nécessaire. En fonctionnement comme capteur de gaz, la puissance doit être aussi faible que possible afin de garantir que les variations de résistance ne représentent qu'une réponse gazeuse seule, qui ne soit pas influencée par des facteurs d'évaluation.
PCT/NZ1997/000123 1996-09-12 1997-09-12 Deposition d'un film polymere mince electroconducteur d'une resistance desiree, utilisable dans le domaine de la detection des gaz WO1998011279A1 (fr)

Priority Applications (2)

Application Number Priority Date Filing Date Title
AU44044/97A AU733671B2 (en) 1996-09-12 1997-09-12 Apparatus to deposit and measure the resistance charges of thin conducting polymer films in gas sensing applications
EP97942321A EP0931183A4 (fr) 1996-09-12 1997-09-12 Deposition d'un film polymere mince electroconducteur d'une resistance desiree, utilisable dans le domaine de la detection des gaz

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
NZ29933396 1996-09-12
NZ299332 1996-09-12
NZ299333 1996-09-12
NZ29933296 1996-09-12

Publications (1)

Publication Number Publication Date
WO1998011279A1 true WO1998011279A1 (fr) 1998-03-19

Family

ID=26651664

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/NZ1997/000123 WO1998011279A1 (fr) 1996-09-12 1997-09-12 Deposition d'un film polymere mince electroconducteur d'une resistance desiree, utilisable dans le domaine de la detection des gaz

Country Status (3)

Country Link
EP (1) EP0931183A4 (fr)
AU (1) AU733671B2 (fr)
WO (1) WO1998011279A1 (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102012222917A1 (de) * 2012-12-12 2014-06-12 Robert Bosch Gmbh Schalt-Schütz, Batterie mit dem Schalt-Schütz und Verfahren zur Bestimmung eines elektrischen Kontaktwiderstands beim Schalt-Schütz

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4468291A (en) * 1982-07-14 1984-08-28 Basf Aktiengesellschaft Continuous production of polypyrrole films
EP0144127A1 (fr) * 1983-10-07 1985-06-12 Nippon Telegraph And Telephone Corporation Polymère conducteur et son procédé de fabrication
DE3508266A1 (de) * 1985-03-08 1986-09-11 Basf Ag, 6700 Ludwigshafen Verfahren zur herstellung von verbundstoffen aus metallen und elektrisch leitfaehigen polymeren
EP0234467A2 (fr) * 1986-02-18 1987-09-02 The B.F. GOODRICH Company Composite hétérogène de polypyrrole sans électrode
US4728399A (en) * 1985-03-02 1988-03-01 Basf Aktiengesellschaft Preparation of laminates of metals and electrically conductive polymers
WO1990002829A1 (fr) * 1988-09-07 1990-03-22 Wollongong Uniadvice Limited Micro-electrodes recouvertes d'electropolymere
EP0495303A2 (fr) * 1990-12-17 1992-07-22 Ford Motor Company Limited Disposition de polymères électroactifs
WO1992013007A1 (fr) * 1991-01-18 1992-08-06 Drexel University Polymerisation de la pyrrole et de ses derives

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4468291A (en) * 1982-07-14 1984-08-28 Basf Aktiengesellschaft Continuous production of polypyrrole films
EP0144127A1 (fr) * 1983-10-07 1985-06-12 Nippon Telegraph And Telephone Corporation Polymère conducteur et son procédé de fabrication
US4728399A (en) * 1985-03-02 1988-03-01 Basf Aktiengesellschaft Preparation of laminates of metals and electrically conductive polymers
DE3508266A1 (de) * 1985-03-08 1986-09-11 Basf Ag, 6700 Ludwigshafen Verfahren zur herstellung von verbundstoffen aus metallen und elektrisch leitfaehigen polymeren
EP0234467A2 (fr) * 1986-02-18 1987-09-02 The B.F. GOODRICH Company Composite hétérogène de polypyrrole sans électrode
WO1990002829A1 (fr) * 1988-09-07 1990-03-22 Wollongong Uniadvice Limited Micro-electrodes recouvertes d'electropolymere
EP0495303A2 (fr) * 1990-12-17 1992-07-22 Ford Motor Company Limited Disposition de polymères électroactifs
WO1992013007A1 (fr) * 1991-01-18 1992-08-06 Drexel University Polymerisation de la pyrrole et de ses derives

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
PATENT ABSTRACTS OF JAPAN, Vol. 15, No. 231; & JP,A,03 072 097 (OMRON CORP), 27 March 1991. *
See also references of EP0931183A4 *

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102012222917A1 (de) * 2012-12-12 2014-06-12 Robert Bosch Gmbh Schalt-Schütz, Batterie mit dem Schalt-Schütz und Verfahren zur Bestimmung eines elektrischen Kontaktwiderstands beim Schalt-Schütz

Also Published As

Publication number Publication date
AU4404497A (en) 1998-04-02
AU733671B2 (en) 2001-05-24
EP0931183A4 (fr) 2001-03-07
EP0931183A1 (fr) 1999-07-28

Similar Documents

Publication Publication Date Title
Partridge et al. High sensitivity conducting polymer sensors
Bartlett et al. Conducting polymer gas sensors part I: fabrication and characterization
US4236527A (en) Cardiac output detection by multiple frequency thermodilution
CA2285342C (fr) Procede et dispositif de detection du contact du tissu avec un catheter, ainsi que des interactions avec le tissu lors de l'ablation par catheter
EP0286307B1 (fr) Capteur de gaz
EP1042651B1 (fr) Test d'integrite pour electrodes
EP1768545B1 (fr) Procede et dispositif permettant de determiner un parametre d'un tissu vivant
DE69623006T2 (de) Sensor
EP0766818B1 (fr) Polymeres organiques semi-conducteurs pour des detecteurs de gaz
EP0429439B1 (fr) Technique amelioree pour la mesure d'eaux de grande purete
CN109187656A (zh) 测量物质的电学性能的装置和方法
Coster et al. Low-frequency impedance of Chara coralinna: simultaneous measurements of the separate plasmalemma and tonoplast capacitance and conductance
EP0766819B1 (fr) Capteur gazeux comprenant des polymeres organiques semi-conducteurs
Kalinowski et al. A four-electrode system for measurement of bilayer lipid membrane capacitance
Valdiosera et al. Measurement of the impedance of frog skeletal muscle fibers
AU733671B2 (en) Apparatus to deposit and measure the resistance charges of thin conducting polymer films in gas sensing applications
Charlier et al. Electropolymerization of methacrylonitrile and N-vinyl-2-pyrrolidone as probed by an EQCM
DE69722926T2 (de) Vorrichtung und verfahren zur feststellung eines fluids
US5532606A (en) Electrical testing process
US4842886A (en) Method for electroless plating
Park et al. Bridge balance in intracellular recording; introduction of the phase-sensitive method
GB2117120A (en) Anodic stripping voltameter
Popkirov et al. Electrochemical impedance spectroscopy of twin working electrodes bridged with conducting polymer layer
SU1174834A1 (ru) Способ испытани полимерных покрытий
RU2268644C2 (ru) Способ измерения электрокожного сопротивления точек акупунктуры, устройство для осуществления способа и их варианты

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): AL AM AT AU AZ BA BB BG BR BY CA CH CN CU CZ DE DK EE ES FI GB GE GH HU ID IL IS JP KE KG KP KR KZ LC LK LR LS LT LU LV MD MG MK MN MW MX NO NZ PL PT RO RU SD SE SG SI SK SL TJ TM TR TT UA UG US UZ VN YU ZW AM AZ BY KG KZ MD RU TJ TM

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): GH KE LS MW SD SZ UG ZW AT BE CH DE DK ES FI FR GB GR IE IT LU MC

DFPE Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed before 20040101)
121 Ep: the epo has been informed by wipo that ep was designated in this application
WWE Wipo information: entry into national phase

Ref document number: 1997942321

Country of ref document: EP

NENP Non-entry into the national phase

Ref country code: JP

Ref document number: 1998513540

Format of ref document f/p: F

REG Reference to national code

Ref country code: DE

Ref legal event code: 8642

WWP Wipo information: published in national office

Ref document number: 1997942321

Country of ref document: EP

NENP Non-entry into the national phase

Ref country code: CA

WWW Wipo information: withdrawn in national office

Ref document number: 1997942321

Country of ref document: EP

点击 这是indexloc提供的php浏览器服务，不要输入任何密码和下载