EP0587032B1 - Integrated capacitive transducer - Google Patents
Integrated capacitive transducer Download PDFInfo
- Publication number
- EP0587032B1 EP0587032B1 EP93113955A EP93113955A EP0587032B1 EP 0587032 B1 EP0587032 B1 EP 0587032B1 EP 93113955 A EP93113955 A EP 93113955A EP 93113955 A EP93113955 A EP 93113955A EP 0587032 B1 EP0587032 B1 EP 0587032B1
- Authority
- EP
- European Patent Office
- Prior art keywords
- transducer according
- electrode
- layer
- membrane
- electret
- Prior art date
- Legal status (The legal status 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 status listed.)
- Expired - Lifetime
Links
- 239000012528 membrane Substances 0.000 claims description 28
- 239000000758 substrate Substances 0.000 claims description 16
- 239000011810 insulating material Substances 0.000 claims description 7
- 125000006850 spacer group Chemical group 0.000 claims description 4
- 239000000725 suspension Substances 0.000 claims 2
- 239000004020 conductor Substances 0.000 claims 1
- 230000001419 dependent effect Effects 0.000 claims 1
- 230000008719 thickening Effects 0.000 claims 1
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 9
- 229910052710 silicon Inorganic materials 0.000 description 9
- 239000010703 silicon Substances 0.000 description 9
- 238000004519 manufacturing process Methods 0.000 description 8
- 238000002347 injection Methods 0.000 description 6
- 239000007924 injection Substances 0.000 description 6
- 239000000463 material Substances 0.000 description 6
- 238000000034 method Methods 0.000 description 5
- 230000035945 sensitivity Effects 0.000 description 5
- 239000012212 insulator Substances 0.000 description 4
- 230000014759 maintenance of location Effects 0.000 description 4
- 239000004809 Teflon Substances 0.000 description 3
- 229920006362 Teflon® Polymers 0.000 description 3
- 238000002513 implantation Methods 0.000 description 3
- 239000004065 semiconductor Substances 0.000 description 3
- 229910004298 SiO 2 Inorganic materials 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 230000006870 function Effects 0.000 description 2
- 238000009434 installation Methods 0.000 description 2
- 238000009413 insulation Methods 0.000 description 2
- 230000007246 mechanism Effects 0.000 description 2
- 229910021420 polycrystalline silicon Inorganic materials 0.000 description 2
- 229920005591 polysilicon Polymers 0.000 description 2
- 229920002799 BoPET Polymers 0.000 description 1
- 230000005689 Fowler Nordheim tunneling Effects 0.000 description 1
- 239000005041 Mylar™ Substances 0.000 description 1
- 210000004027 cell Anatomy 0.000 description 1
- 230000000295 complement effect Effects 0.000 description 1
- 239000003989 dielectric material Substances 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 230000005520 electrodynamics Effects 0.000 description 1
- 238000010894 electron beam technology Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 229920006335 epoxy glue Polymers 0.000 description 1
- 230000005669 field effect Effects 0.000 description 1
- 238000004377 microelectronic Methods 0.000 description 1
- 230000003071 parasitic effect Effects 0.000 description 1
- 230000010287 polarization Effects 0.000 description 1
- 239000005020 polyethylene terephthalate Substances 0.000 description 1
- 229920000139 polyethylene terephthalate Polymers 0.000 description 1
- 229920001343 polytetrafluoroethylene Polymers 0.000 description 1
- 239000004810 polytetrafluoroethylene Substances 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 230000004044 response Effects 0.000 description 1
- 238000002444 silanisation Methods 0.000 description 1
- 238000012995 silicone-based technology Methods 0.000 description 1
- 238000003466 welding Methods 0.000 description 1
Images
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
- H04R19/00—Electrostatic transducers
- H04R19/005—Electrostatic transducers using semiconductor materials
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
- H04R19/00—Electrostatic transducers
- H04R19/01—Electrostatic transducers characterised by the use of electrets
- H04R19/016—Electrostatic transducers characterised by the use of electrets for microphones
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
- H04R25/00—Deaf-aid sets, i.e. electro-acoustic or electro-mechanical hearing aids; Electric tinnitus maskers providing an auditory perception
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
- H04R25/00—Deaf-aid sets, i.e. electro-acoustic or electro-mechanical hearing aids; Electric tinnitus maskers providing an auditory perception
- H04R25/60—Mounting or interconnection of hearing aid parts, e.g. inside tips, housings or to ossicles
- H04R25/604—Mounting or interconnection of hearing aid parts, e.g. inside tips, housings or to ossicles of acoustic or vibrational transducers
Definitions
- the invention relates to a capacitive transducer. integrated and more particularly such a transducer electret in which the electret exhibits excellent charge retention and in which the distribution of loads is homogeneous.
- Such transducers are in particular intended for use as a microphone for prostheses hearing aids
- transducers or microphones used generally we find mainly transducers capacitive, piezoelectric and electro-dynamic type.
- the capacitive type transducers are distinguish by their sensitivity, their bandwidth, their stability and their low consumption and are, for these qualities, generally used in devices hearing aids.
- these transducers can be made of silicon in relatively small dimensions which allow the prostheses in which they are used to be easily miniaturized so that they are easily integrated into the ear.
- the transducers used in hearing aids currently on the market have dimensions of the order of 3.6 x 3.6 x 2.3 mm 3 .
- Teflon ® does not support high temperatures, electrets made using this material are not easily compatible with silicon-based technologies used in the manufacture of the rest of the transducer structure.
- the capacitive transducer electret comprises a rigid base made of silicon, carried by techniques analogous to those used in the manufacture of semiconductor devices and associated with a Mylar ® sheet (PET) forming the membrane of the transducer.
- PET Mylar ® sheet
- a layer of Si0 2 formed from the base and facing the membrane, in which charges have been implanted forms the electret.
- the charge of the electret must be done before the membrane is attached to the base.
- this charge must be carried out using costly implantation techniques, such as Corona implantation or electron beam implantation.
- charging the electret before the membrane is reported on the base limits the choice of manufacturing techniques that can be used later on this charging step so as not to deteriorate this charge.
- the bonding of the membrane to the base should be made at low temperature, for example, with epoxy glue.
- an electret thus formed discharges quickly so that it is necessary to treat the surface of SiO 2 , for example, by means of silanization in order to reduce the surface conduction and thereby increase even charge retention in the SiO 2 layer.
- the result of the latter remains ineffective due to its instability over time.
- the main aim of the invention is therefore to remedy the disadvantages of the aforementioned prior art in providing a capacitive transducer with integrated electret, which has an electret structure allowing it to be homogeneously and simply electrically charged with good charge retention properties and the state of charge can be precisely controlled, both during and after manufacturing the transducer.
- the transducer according to the invention can be, as the case if necessary, recharged, so that its lifespan is significantly increased compared to transducers at electret of the prior art.
- Another object of the invention is to provide a electret transducer can be achieved using complementary technologies of micromechanics and microelectronics.
- said transducer is characterized in that that said electret has a first layer conductive embedded in an insulating material.
- the charges introduced into the layer conductive are distributed homogeneously therein.
- the conductive layer embedded in a material insulation exhibits good retention characteristics of charges.
- FIG. 1 we see a plan view partially torn off from an integrated capacitive transducer according to the invention which is designated by the reference general 1.
- Figure 1 will be better understood by referring simultaneously with Figure 2.
- the capacitive transducer 1 generally comprises a upper plate 2 comprising a first electrode 4, an intermediate plate 6 comprising a second fixed electrode 8 ( Figure 3) and a bottom plate 10 forming, on the one hand, a support structure for the assembly formed by the two plates 2 and 6 and, on the other share, a rear chamber 12 of the transducer.
- the intermediate plate 6 is fixed, by means of a insulating spacer 14, to the upper plate 2 which is its turn fixed by its periphery to the support structure 10.
- the spacer 14 separates the upper plate 2 from the intermediate plate 6, leaving an open space 16 between the two plates 2 and 6, and electrically insulates the plates 2 and 6 from each other.
- the structure comprising plates 2 and 6, comprising electrodes 4 and 8, thus forms the element transducer capacitance 1.
- the upper plate 2 has a frame 18 to the interior of which extends the electrode 4.
- This electrode consists of a thin sheet, which is connected to the frame 18 by an inner edge 20.
- the electrode 4 forms also the mobile part or membrane of the transducer 1.
- the frame 18 and the electrode 4 advantageously have a structure monolithic and are made of a material semiconductor such as silicon.
- this monolithic structure advantageously reduces sensitivity to variations temperature, thus increasing the reliability of the transducer.
- frame 18 and the transducer membrane can be made in one piece and that the electrode 4 can be reported on the membrane.
- the materials used for the frame and the membrane are not necessarily electrically conductive.
- the upper plate 2 further comprises contact windows 22a-22d provided in the corners of the frame 18 for making electrical contacts with elements (described below) of the intermediate plate 6.
- the edges of these contact windows 22a-22d are coated a layer of insulating material 26a-26d.
- the intermediate plate 6 comprises, in addition to the electrode 8, an electret 30 comprising a first layer electrically conductive 32 embedded between two layers 34, 36 of an insulating material.
- Electret 30 extends substantially opposite the membrane 4 of the top plate 2.
- the plate 6 comprises a substrate 38 on the surface of which is a second layer electrically conductive forming the second electrode 8 fixed.
- the electret 30 is arranged on the surface of the second electrode 8.
- first insulating layer 34 the material layer insulator 34, in direct contact with the second electrode 8 will be called first insulating layer 34 and the layer of insulating material 36 extending opposite the part mobile 4 will be called second insulating layer 36.
- the intermediate plate 6 is connected to the upper plate 2 by a plurality of arms 40a-40h extending from plate 6 and the end of which is located opposite frame 18 to which they are fixed by through the spacers 14.
- the arms 40a-40h are formed by extensions of substrate 38 which extend respectively from the four corners of the plate 6 and from the middle of the sides of the plate 6.
- this structure for fixing the intermediate plate 6 to the upper plate by arms contributes to increasing the sensitivity of the transducer 1 by minimizing the parasitic capacity formed by the parts of the fixed plate located in the vicinity of the frame 18.
- a structure in connection with a membrane 4 having a thickness of the order of 3.65 x 10 -6 m makes it possible to achieve a sensitivity greater than 10mv / Pa.
- the second conductive layer or electrode 8 extends to the surface an arm 40a to form at its end a surface of contact 42 of electrode 8 with the outside.
- This surface 42 is of course not covered with layers insulating 34 and 36 and is located next to the window contact 22a.
- the substrate 38 is made in lightly p-doped silicon with orientation ⁇ 100>
- the second conductive layer 8 is formed by an n + doped region
- the first and second insulating layers 34 and 36 are made of oxide of silicon
- the first conductive layer 32 is made of doped polysilicon.
- the plate 6 further comprises in its zone opposite the electrode or movable part 4, a plurality of holes through 44 regularly distributed in lines and columns. These holes 44 reduce the acoustic resistance between the membrane 4 and the plate 6 and provide, in combination with the open space 16, a device of the acoustic structure of the transducer 1; which significantly improves the acoustic properties of the last. It is indeed possible to adjust the frequency response, e.g. bandwidth, transducer by a judicious arrangement of these holes.
- the intermediate plate 6 further comprises load means 46 and control means 48 of the charge of electret 30. We will refer more particularly in Figures 3, 5 and 6 to describe these means 46 and 48.
- the charging means 46 of the electret 30 comprise a third electrically conductive layer 50 disposed on the surface of the substrate 38.
- the layer 50 extends on the arm 40b and is isolated from the second electrode 8 by an extra thickness portion 52 of the first layer insulating 34.
- the first insulating layer 34 is extended and covers part of the layer 50; the no part covered with the latter constituting a surface of contact 54, which is arranged next to the window contact 22b of the frame 18.
- the first conductive layer 32 as well as the second insulating layer 36 extend also above layer 50. In this extension an injection area 56 is provided in which the thickness of the first insulating layer 34 between the conductive layers 32 and 50 is weak.
- the injection will take place more favorably if the relationship between the capacitance, which is formed by the counter electrode 8, the first insulating layer 34 and the layer conductive 32 and the capacitance, which is formed by the conductive layer 50, said first insulating layer 34 and the conductive layer 32, is large.
- the charging mechanism of the electret 30 is simpler than in the structures of the prior art and the charge can be easily checked and possibly adjusted after blow in order to obtain the desired charge density.
- the loads are distributed evenly across the insulated conductive layer 32. Also these means of load simplify the entire manufacturing process of the transducer in that they allow to charge the electret like any last operation so we can implement wet and high process steps temperature without having to take into account a possible discharge of the electret.
- Means for controlling the charge 48 of the electret 30 include a fourth layer electrically conductive 58 disposed on the surface of the substrate 38.
- the layer 58 extends over the arm 40c and is isolated from the second electrode 8 by a shoulder 60 of the substrate 38. At this shoulder 60, the substrate 38 is separated of the conductive layer 32 by a part of less thickness 62 of the first insulating layer 34.
- the first insulating layer 34 is extended and covers a part of the layer 58 and leaves a contact surface 64 (arranged opposite the contact window 22c of the frame contact 18).
- the first conductive layer 32 thus that the second insulating layer 36 also covers part of layer 58 so the layer conductive 32, forming the part which holds the charges of the electret 30, extends at least above the part thinner 62 and be completely isolated from outside.
- the structure of the load control means 48 thus forms a field effect transistor in which the source is formed by the conductive layer 8, the drain is formed by the conductive layer 58 and the grid is formed by the conductive layer 32.
- the sourcedrain current being a function among other things of the burden of grid (layer 32), measuring this current allows easily determine the state of charge of the electret 30 and readjust it using the load means 46 if this is necessary.
- the arm 40d comprises a part of substrate not covered by the insulating layers 34 and 36 forms a contact surface 66 which extends opposite contact window 22d and which allows you to control and to fix the potential of the substrate 38.
- the lower plate 10 forming the support means of the capacitive element of the transducer 1 comprises a element of generally planar shape and on one side of which a cavity has been formed forming the rear chamber 12 which is arranged opposite the intermediate plate 6.
- the cavity 12 includes a shoulder 68 which extends to its periphery substantially opposite frame 18 of the plate 6 and thus delimits a rim or rib 70 by which the lower plate 10 is connected to the upper plate 2.
- the plate 10 has a monolithic structure and is, like frame 18, made of a semiconductor material such as silicon. The fixing of the plate 10 on the frame 18 can thus be produced by simple welding silicon on silicon.
- the transducer of the invention has general dimensions of 2.3 x 2.3 x 1.0 mm 3 .
- the surface of the mobile part is 2.0 x 2.0 mm 2
- the thickness of the membrane is approximately 3.65 x 10 -6 m
- the thickness of the intermediate plate 6 is approximately 10 x 10 -6 m
- the thickness of the air film in the open space 14 is approximately 3 x 10 -6 m
- the internal volume delimited by the cavity 11 is approximately 5 mm 3 .
- the holes they have a diameter of approximately 30 x 10 -6 m and are approximately 400 per mm 2 so that they occupy approximately 28% of the surface of the membrane.
Description
L'invention concerne un transducteur capacitif intégré et plus particulièrement un tel transducteur à électret dans lequel l'électret présente une excellente rétention de charges et dans lequel la distribution de charges est homogène. De tels transducteurs sont notamment destinés à être utilisés comme microphone pour prothèses auditivesThe invention relates to a capacitive transducer. integrated and more particularly such a transducer electret in which the electret exhibits excellent charge retention and in which the distribution of loads is homogeneous. Such transducers are in particular intended for use as a microphone for prostheses hearing aids
Parmi les transducteurs ou microphones utilisés généralement on trouve principalement des transducteurs de type capacitif, piézo-électrique et électro-dynamique. Parmi ceux-ci, les transducteurs de type capacitif se distinguent par leur sensibilité, leur bande passante, leur stabilité et leur faible consommation et sont, pour ces qualités, généralement utilisés dans les appareils auditifs.Among the transducers or microphones used generally we find mainly transducers capacitive, piezoelectric and electro-dynamic type. Among these, the capacitive type transducers are distinguish by their sensitivity, their bandwidth, their stability and their low consumption and are, for these qualities, generally used in devices hearing aids.
Ces transducteurs capacitifs, bien que fonctionnant de façon satisfaisante, présentent l'inconvénient de nécessiter l'utilisation d'une polarisation externe qui doit être relativement élevée, à savoir, de l'ordre de quelques dizaines, voire quelques centaines de volts.These capacitive transducers, although operating satisfactorily, have the disadvantage of require the use of an external bias which must be relatively high, i.e., in the range of a few tens, even a few hundred volts.
Pour pallier cet inconvénient on a proposé des transducteurs capacitifs à électret. Ces transducteurs, qui dominent actuellement le marché pour les applications aux prothèses auditives avec plus de 3 millions de pièces vendues par année, se caractérisent en ce qu'ils ne nécessitent pas de polarisation externe pour pouvoir fonctionner.To overcome this drawback, we have proposed capacitive electret transducers. These transducers, that currently dominate the market for applications hearing aids with more than 3 million pieces sold per year, are characterized in that they do not do not need external polarization to be able to function.
En effet, les charges électriques piégées, de façon quasi-permanente, dans une couche de matériau diélectrique sur un des substrats des électrodes du transducteur, suffisent à fournir la tension de polarisation nécessaire à son fonctionnement. Indeed, the electrical charges trapped, so almost permanent, in a layer of dielectric material on one of the substrates of the transducer electrodes, sufficient to supply the necessary bias voltage to its operation.
De plus, ces transducteurs peuvent être réalisés en silicium dans des dimensions relativement petites qui permettent, aux prothèses dans lesquelles ils sont utilisés, d'être facilement miniaturisées pour qu'elles soient facilement intégrées dans l'oreille. Typiquement, les transducteurs utilisés dans les prothèses auditives actuellement sur le marché ont des dimensions de l'ordre de 3,6 x 3,6 x 2,3 mm3.In addition, these transducers can be made of silicon in relatively small dimensions which allow the prostheses in which they are used to be easily miniaturized so that they are easily integrated into the ear. Typically, the transducers used in hearing aids currently on the market have dimensions of the order of 3.6 x 3.6 x 2.3 mm 3 .
La fabrication de ces transducteurs capacitifs à électret pose toutefois certains problèmes.The manufacture of these capacitive transducers electret poses certain problems, however.
En effet, les électrets classiques, qui sont généralement formés dans des films de Teflon® (PTFE), présentent l'inconvénient de se décharger notablement au cours du temps. Ce processus de décharge, qui augmente avec la température et l'humidité, diminue la sensibilité du transducteur et affecte sa durée de vie.Indeed, conventional electrets, which are generally formed in films of Teflon ® (PTFE), have the drawback to substantially discharge over time. This discharge process, which increases with temperature and humidity, decreases the sensitivity of the transducer and affects its lifespan.
En l'occurrence, il est nécessaire d'utiliser une couche de Teflon® de quelques 12 micromètres, ce qui diminue les performances générales du transducteur et augmente de façon désavantageuse l'épaisseur de l'ensemble du transducteur.In this case, it is necessary to use a layer of Teflon ® some 12 micrometers, which decreases the overall performance of the transducer and increases disadvantageously the thickness of the transducer assembly.
Par ailleurs, comme le Teflon® ne supporte pas les températures élevées, les électrets réalisés à l'aide de ce matériau sont difficilement compatibles avec les technologies du silicium utilisées dans la fabrication du reste de la structure du transducteur.Furthermore, such as Teflon ® does not support high temperatures, electrets made using this material are not easily compatible with silicon-based technologies used in the manufacture of the rest of the transducer structure.
Une autre approche dite hybride est décrite dans la publication intitulée "Development of an electret microphone in silicon" de A. J. Sprenkels et al., dans la revue Sensors and Actuators, 17(1989) aux pages 509-512.Another so-called hybrid approach is described in publication entitled "Development of an electret microphone in silicon "by A. J. Sprenkels et al., in the Sensors and Actuators, 17 (1989) at pages 509-512.
Dans cette publication, le transducteur capacitif à électret comprend une base rigide en silicium, réalisée par les techniques analogues à celles utilisées pour la fabrication de dispositifs semiconducteurs et associée à une feuille de Mylar® (PETP) qui forme la membrane du transducteur. Une couche de Si02, formée à partir de la base et en regard de la membrane, dans laquelle des charges ont été implantées forme l'électret.In this publication, the capacitive transducer electret comprises a rigid base made of silicon, carried by techniques analogous to those used in the manufacture of semiconductor devices and associated with a Mylar ® sheet (PET) forming the membrane of the transducer. A layer of Si0 2 , formed from the base and facing the membrane, in which charges have been implanted forms the electret.
Cette approche présente, toutefois, encore des inconvénients.This approach, however, still presents disadvantages.
En effet, puisque la couche de Si02 est isolante, la charge de l'électret doit se faire avant que la membrane soit rapportée sur la base. En outre cette charge doit être effectuée à l'aide de techniques d'implantation coûteuses, telles que l'implantation Corona ou l'implantation à faisceau d'électrons.Indeed, since the layer of Si0 2 is insulating, the charge of the electret must be done before the membrane is attached to the base. In addition, this charge must be carried out using costly implantation techniques, such as Corona implantation or electron beam implantation.
De plus, le fait de charger l'électret avant que la membrane soit rapportée sur la base limite le choix des techniques de fabrication utilisables ultérieurement à cette étape de charge afin de ne pas détériorer cette charge. En particulier, le collage de la membrane sur la base doit être réalisé à basse température, par exemple, avec une colle epoxy.In addition, charging the electret before the membrane is reported on the base limits the choice of manufacturing techniques that can be used later on this charging step so as not to deteriorate this charge. In particular, the bonding of the membrane to the base should be made at low temperature, for example, with epoxy glue.
Par ailleurs, on constate qu'un électret ainsi formé se décharge rapidement de sorte qu'il est nécessaire de traiter la surface de SiO2, par exemple, au moyen d'une silanisation afin de réduire la conduction de surface et augmenter par-là même la rétention des charges dans la couche de SiO2. Cependant, outre l'augmentation du coût de mise en oeuvre de ce traitement, le résultat de ce dernier demeure peu efficace du fait de son instabilité dans le temps.Furthermore, it is found that an electret thus formed discharges quickly so that it is necessary to treat the surface of SiO 2 , for example, by means of silanization in order to reduce the surface conduction and thereby increase even charge retention in the SiO 2 layer. However, in addition to the increase in the cost of implementing this treatment, the result of the latter remains ineffective due to its instability over time.
Aussi, pour charger uniformément les deux types d'électret mentionnés ci-dessus, il est nécessaire d'utiliser des installations de charge qui puissent balayer la surface de l'électret. Là encore la mise en oeuvre de ces installations est coûteuse et constitue une contrainte de fabrication supplémentaire qu'il est souhaitable d'éliminer.Also, to load both types evenly electret mentioned above, it is necessary to use charging facilities which can sweep the surface of the electret. Again the implementation installation of these installations is expensive and constitutes a additional manufacturing constraint that it is desirable to eliminate.
Enfin, la charge des types d'électret susmentionnés ne peut être ni modifiée, ni contrôlée après sa fabrication de sorte qu'il en résulte une durée de vie limitée de l'électret compte tenu des pertes de charge inévitables au cours du temps.Finally, the charge of the aforementioned types of electret cannot be modified or checked after its manufacturing so it results in a lifetime limited electret due to pressure losses inevitable over time.
L'invention a donc pour but principal de remédier aux inconvénients de l'art antérieur susmentionné en fournissant un transducteur capacitif à électret intégré, qui présente une structure d'électret permettant d'être chargée électriquement de façon homogène et simple avec de bonnes propriétés de rétention de charge et dont l'état de charge peut-être contrôlé précisément, à la fois au cours et après la fabrication du transducteur.The main aim of the invention is therefore to remedy the disadvantages of the aforementioned prior art in providing a capacitive transducer with integrated electret, which has an electret structure allowing it to be homogeneously and simply electrically charged with good charge retention properties and the state of charge can be precisely controlled, both during and after manufacturing the transducer.
Le transducteur selon l'invention peut être, le cas échéant, rechargé, si bien que sa durée de vie est considérablement augmentée par rapport aux transducteurs à électret de l'art antérieur.The transducer according to the invention can be, as the case if necessary, recharged, so that its lifespan is significantly increased compared to transducers at electret of the prior art.
Un autre but de l'invention est de fournir un transducteur à électret pouvant être réalisé en utilisant des technologies complémentaires de la micromécanique et de la microélectronique.Another object of the invention is to provide a electret transducer can be achieved using complementary technologies of micromechanics and microelectronics.
L'invention a donc pour objet un transducteur capacitif intégré comprenant:
- une membrane comportant une partie mobile munie d'une électrode,
- une plaque fixe comportant une contre-électrode,
- une structure de support de l'électrode et de la contre-électrode,
- a membrane comprising a movable part provided with an electrode,
- a fixed plate comprising a counter-electrode,
- a support structure for the electrode and the counter-electrode,
Conformément à la partie caractérisante de la
revendication 1, ledit transducteur est caractérisé en ce
que ledit électret comporte une première couche
conductrice noyée dans un matériau isolant. In accordance with the characterizing part of the
Ainsi, les charges introduites dans la couche conductrice se distribuent de façon homogène dans celle-ci. De plus, la couche conductrice noyée dans une matière isolante présente de bonnes caractéristiques de rétention de charges. Thus, the charges introduced into the layer conductive are distributed homogeneously therein. In addition, the conductive layer embedded in a material insulation exhibits good retention characteristics of charges.
D'autres caractéristiques et avantages de l'invention apparaítront clairement à la lecture de la description qui suit d'un mode de réalisation du transducteur donné à titre d'exemple non limitatif et en liaison avec les dessins annexés parmi lesquels :
- la figure 1 est une vue schématique de dessus partiellement arrachée du transducteur capacitif à électret intégré selon l'invention;
- la figure 2 est une coupe schématique selon la ligne II-II de la figure 1;
- la figure 3 est une vue schématique de dessus de la plaque fixe munie d'un électret et formant contre-électrode dans laquelle les trous et la couche supérieure d'isolant ont été omis;
- la figure 4 est une coupe partielle schématique agrandie, selon la ligne IV-IV de la figure 3, de la plaque fixe formant contre-électrode munie de l'électret avec la couche supérieure d'isolant;
- la figure 5 est une coupe partielle schématique agrandie selon la ligne V-V de la figure 3 des moyens d'injection de charges dans l'électret avec la couche supérieure d'isolant; et
- la figure 6 est une coupe partielle schématique agrandie selon la ligne VI-VI de la figure 3 des moyens de contrôle de l'état de charge de l'électret avec la couche supérieure d'isolant.
- Figure 1 is a schematic top view partially cut away of the capacitive transducer with integrated electret according to the invention;
- Figure 2 is a schematic section along the line II-II of Figure 1;
- Figure 3 is a schematic top view of the fixed plate provided with an electret and forming a counter electrode in which the holes and the upper layer of insulation have been omitted;
- Figure 4 is an enlarged schematic partial section along the line IV-IV of Figure 3, of the fixed plate forming a counter electrode provided with the electret with the upper layer of insulator;
- Figure 5 is an enlarged schematic partial section along the line VV of Figure 3 of the charge injection means in the electret with the upper layer of insulator; and
- Figure 6 is an enlarged schematic partial section along line VI-VI of Figure 3 of the means of controlling the state of charge of the electret with the upper layer of insulator.
En se référant à la figure 1 on voit une vue en plan partiellement arrachée d'un transducteur capacitif intégré selon l'invention qui est désigné par la référence générale 1. La figure 1 sera mieux comprise en se référant simultanément à la figure 2.Referring to Figure 1 we see a plan view partially torn off from an integrated capacitive transducer according to the invention which is designated by the reference general 1. Figure 1 will be better understood by referring simultaneously with Figure 2.
Le transducteur capacitif 1 comprend généralement une
plaque supérieure 2 comportant une première électrode 4,
une plaque intermédiaire 6 comportant une deuxième
électrode fixe 8 (figure 3) et une plaque inférieure 10
formant, d'une part, une structure de support de
l'ensemble formé par les deux plaques 2 et 6 et, d'autre
part, une chambre arrière 12 du transducteur.The
La plaque intermédiaire 6 est fixée, au moyen d'une
entretoise isolante 14, à la plaque supérieure 2 qui est à
son tour fixée par sa périphérie à la structure de support
10. L'entretoise 14 sépare la plaque supérieure 2 de la
plaque intermédiaire 6 en ménageant un espace ouvert 16
entre les deux plaques 2 et 6, et isole électriquement les
plaques 2 et 6 l'une de l'autre.The
La structure comprenant les plaques 2 et 6,
comportant les électrodes 4 et 8, forme ainsi l'élément
capacitif du transducteur 1.The
La plaque supérieure 2 comporte un cadre 18 à
l'intérieur duquel s'étend l'électrode 4. Cette électrode
est constituée d'une feuille mince, qui est reliée au
cadre 18 par un bord intérieur 20. L'électrode 4 forme
aussi la partie mobile ou membrane du transducteur 1.The
Dans l'exemple de réalisation décrit ici, le cadre 18
et l'électrode 4 présentent avantageusement une structure
monolithique et sont réalisés en un matériau
semiconducteur tel que le silicium.In the embodiment described here, the
On notera au passage que cette structure monolithique diminue de façon avantageuse la sensibilité aux variations de température, augmentant ainsi la fiabilité du transducteur.Note in passing that this monolithic structure advantageously reduces sensitivity to variations temperature, thus increasing the reliability of the transducer.
Il va de soi que, selon une variante de l'invention,
le cadre 18 et la membrane du transducteur peuvent être
réalisés en une seule pièce et que l'électrode 4 peut être
rapportée sur la membrane. Dans ce cas les matériaux
utilisés pour le cadre et la membrane ne sont pas
nécessairement électriquement conducteurs.It goes without saying that, according to a variant of the invention,
La plaque supérieure 2 comprend, en outre, des
fenêtres de contact 22a-22d ménagées dans les coins du
cadre 18 pour établir des contacts électriques avec des
éléments (décrits ci-après) de la plaque intermédiaire 6.
Les bords de ces fenêtres de contact 22a-22d sont revêtus
d'une couche de matériau isolant 26a-26d.The
Pour la description de la plaque intermédiaire 6 on
se référera désormais également aux figures 3 à 6.For the description of the
La plaque intermédiaire 6 comprend, outre l'électrode
8, un électret 30 comportant une première couche
électriquement conductrice 32 noyée entre deux
couches 34, 36 d'un matériau isolant. L'électret 30
s'étend sensiblement en regard de la membrane 4 de la
plaque supérieure 2.The
Plus précisément, la plaque 6 comporte un substrat 38
à la surface duquel se trouve une deuxième couche
électriquement conductrice formant la deuxième électrode 8
fixe. Dans l'exemple représenté aux figures, l'électret 30
est disposé à la surface de la deuxième électrode 8.More specifically, the
Dans la suite de la description la couche de matériau
isolant 34, en contact direct avec la deuxième électrode 8
sera dite première couche isolante 34 et la couche de
matériau isolant 36 s'étendant en regard de la partie
mobile 4 sera dite deuxième couche isolante 36.In the following description, the
Comme cela ressort plus particulièrement des figures
1 et 3, on voit que la plaque intermédiaire 6 est reliée à
la plaque supérieure 2 par une pluralité de bras 40a-40h
s'étendant à partir de la plaque 6 et dont l'extrémité se
trouve en regard du cadre 18 auquel ils sont fixés par
l'intermédiaire des entretoises 14.As can be seen more particularly from the figures
1 and 3, it can be seen that the
Dans l'exemple décrit ici, les bras 40a-40h sont
formés par des extensions du substrat 38 qui s'étendent
respectivement à partir des quatre coins de la plaque 6 et
à partir du milieu des côtés de la plaque 6.In the example described here, the
On remarquera que cette structure de fixation de la
plaque intermédiaire 6 à la plaque supérieure par des bras
contribue à augmenter la sensibilité du transducteur 1 en
réduisant au minimum la capacité parasite formée par les
parties de la plaque fixe se trouvant au voisinage du
cadre 18. A titre d'exemple, une telle structure en
liaison avec une membrane 4 ayant une épaisseur de l'ordre
de 3,65 x 10-6m permet d'atteindre une sensibilité
supérieure à 10mv/Pa.It will be noted that this structure for fixing the
On notera également à ce propos que la deuxième
couche conductrice ou électrode 8 s'étend à la surface
d'un bras 40a pour former à son extrémité une surface de
contact 42 de l'électrode 8 avec l'extérieur. Cette
surface 42 n'est bien entendu pas recouverte des couches
isolantes 34 et 36 et se trouve en regard de la fenêtre de
contact 22a.It should also be noted in this connection that the second
conductive layer or
A titre d'exemple, le substrat 38 est réalisé en
silicium légèrement dopé p et présentant une orientation
de surface <100>, la deuxième couche conductrice 8 est
formée par une région dopée n+, les première et deuxième
couches isolantes 34 et 36 sont réalisées en oxyde de
silicium, et la première couche conductrice 32 est
réalisée en polysilicium dopé.By way of example, the
Comme cela ressort clairement des figures 1 et 2, la
plaque 6 comprend, en outre, dans sa zone en regard de
l'électrode ou partie mobile 4, une pluralité de trous
traversants 44 régulièrement répartis en lignes et en
colonnes. Ces trous 44 diminuent la résistance acoustique
entre la membrane 4 et la plaque 6 et fournissent, en
combinaison avec l'espace ouvert 16, un dispositif
d'amortissement de la structure acoustique du transducteur
1; ce qui améliore sensiblement les propriétés acoustiques
de ce dernier. Il est en effet possible d'ajuster la
réponse en fréquence, par exemple la bande passante, du
transducteur par une disposition judicieuse de ces trous.As is clear from Figures 1 and 2, the
La plaque intermédiaire 6 comprend en outre des
moyens de charge 46 et des moyens de contrôle 48 de la
charge de l'électret 30. On se référera plus
particulièrement aux figures 3, 5 et 6 pour décrire ces
moyens 46 et 48.The
On notera que les couches isolantes 34 et 36 ont été
omises dans la figure 3 pour des raisons de clarté. It will be noted that the insulating
Les moyens de charge 46 de l'électret 30 comprennent
une troisième couche électriquement conductrice 50
disposée à la surface du substrat 38. La couche 50 s'étend
sur le bras 40b et est isolée de la deuxième électrode 8
par une partie en surépaisseur 52 de la première couche
isolante 34. La première couche isolante 34 se prolonge et
recouvre une partie de la couche 50; la partie non
recouverte de cette dernière constituant une surface de
contact 54, qui est disposée en regard de la fenêtre de
contact 22b du cadre 18. La première couche conductrice 32
ainsi que la deuxième couche isolante 36 se prolongent
également au-dessus de la couche 50. Dans ce prolongement
est ménagée une zone d'injection 56 dans laquelle
l'épaisseur de la première couche isolante 34 entre les
couches conductrices 32 et 50 est faible.The charging means 46 of the
Ainsi, pour charger l'électret 30 il suffit
d'appliquer une tension entre les surfaces de contact 42
(reliée à la contre-électrode 8) et 54 afin d'injecter, à
travers la zone d'injection 56 en oxyde mince, des charges
dans la couche 32 en polysilicium.Thus, to charge the
L'injection aura lieu plus favorablement si le
rapport entre la capacité, qui est formée par la contre-électrode
8, la première couche isolante 34 et la couche
conductrice 32 et la capacité , qui est formée par la
couche conductrice 50, ladite première couche isolante 34
et la couche conductrice 32, est grand.The injection will take place more favorably if the
relationship between the capacitance, which is formed by the
Ce mécanisme d'injection de charges à travers un
oxyde mince est dit de type Fowler-Nordheim et est
notamment décrit dans la publication JOURNAL OF APPLIED
PHYSICS, VOLUME 40, NUMBER 1 JANUARY 1969, intitulée
"Fowler-Nordheim Tunneling into Thermally Grown Sio2" par
M. Lenzlinger et E.H. Snow.This charge injection mechanism through a thin oxide is said to be of the Fowler-Nordheim type and is notably described in the publication JOURNAL OF APPLIED PHYSICS,
Grâce à la structure du transducteur décrite le
mécanisme de charge de l'électret 30 est plus simple que
dans les structures de l'art antérieur et la charge peut
être facilement contrôlée et éventuellement ajustée après
coup afin d'obtenir la densité de charges désirée. De
plus, les charges se répartissent de façon uniforme dans
la couche conductrice 32 isolée. Aussi ces moyens de
charge simplifient l'ensemble du procédé de fabrication du
transducteur en ce qu'ils permettent de charger l'électret
comme toute dernière opération si bien que l'on peut
mettre en oeuvre des étapes de procédé humide et à haute
température sans avoir à tenir compte d'une éventuelle
décharge de l'électret.Thanks to the structure of the transducer described the
charging mechanism of the
Les moyens de contrôle de la charge 48 de l'électret
30 comprennent une quatrième couche électriquement
conductrice 58 disposée à la surface du substrat 38. La
couche 58 s'étend sur le bras 40c et est isolée de la
deuxième électrode 8 par un épaulement 60 du substrat 38.
Au niveau de cet épaulement 60, le substrat 38 est séparé
de la couche conductrice 32 par une partie de moindre
épaisseur 62 de la première couche isolante 34. La
première couche isolante 34 se prolonge et recouvre une
partie de la couche 58 et laisse une surface de contact 64
(disposée en regard de la fenêtre de contact 22c du cadre
de contact 18). La première couche conductrice 32 ainsi
que la deuxième couche isolante 36 recouvrent également
une partie de la couche 58 de sorte que la couche
conductrice 32, formant la partie qui retient les charges
de l'électret 30, s'étend au moins au dessus de la partie
de moindre épaisseur 62 et soit complètement isolée de
l'extérieur.Means for controlling the
La structure des moyens de contrôle de la charge 48
forme ainsi un transistor à effet de champ dans lequel la
source est formée par la couche conductrice 8, le drain
est formé par la couche conductrice 58 et la grille est
formée par la couche conductrice 32. Le courant sourcedrain
étant fonction entre autres de la charge de la
grille (la couche 32), la mesure de ce courant permet de
déterminer facilement l'état de charge de l'électret 30 et
de le réajuster à l'aide des moyens de charge 46 si cela
est nécessaire.The structure of the load control means 48
thus forms a field effect transistor in which the
source is formed by the
On notera encore que le bras 40d comprend une partie
de substrat non recouverte par les couches isolantes 34 et
36 forme une surface de contact 66 qui s'étend en regard
de la fenêtre de contact 22d et qui permet de contrôler et
de fixer le potentiel du substrat 38.It will also be noted that the arm 40d comprises a part
of substrate not covered by the insulating
La plaque inférieure 10 formant les moyens de support
de l'élément capacitif du transducteur 1 comprend un
élément de forme générale plane et sur une des face duquel
a été ménagée une cavité formant la chambre arrière 12 qui
est disposée en regard de la plaque intermédiaire 6. La
cavité 12 comprend un épaulement 68 qui s'étend à sa
périphérie sensiblement en regard du cadre 18 de la plaque
6 et délimite ainsi un rebord ou nervure 70 par lequel la
plaque inférieure 10 est reliée à la plaque supérieure 2.
La plaque 10 présente une structure monolithique et est,
comme le cadre 18, réalisée en un matériau semiconducteur
tel que le silicium. La fixation de la plaque 10 sur le
cadre 18 peut être ainsi réalisée par une simple soudure
silicium sur silicium.The
Pour fixer les idées, le transducteur de l'invention
a des dimensions générales de 2,3 x 2,3 x 1,0 mm3. La
surface de la partie mobile est de 2,0 x 2,0 mm2,
l'épaisseur de la membrane est d'environ 3,65 x 10-6 m,
l'épaisseur de la plaque intermédiaire 6 est d'environ 10
x 10-6 m, l'épaisseur du film d'air dans l'espace ouvert
14 est d'environ 3 x 10-6 m, et le volume interne délimité
par la cavité 11 est d'environ 5 mm3. Quant aux trous ils
ont un diamètre d'environ 30 x 10-6 m et sont au nombre
d'environ 400 par mm2 de sorte qu'ils occupent environ 28%
de la surface de la membrane.To fix ideas, the transducer of the invention has general dimensions of 2.3 x 2.3 x 1.0 mm 3 . The surface of the mobile part is 2.0 x 2.0 mm 2 , the thickness of the membrane is approximately 3.65 x 10 -6 m, the thickness of the
Claims (16)
- Integrated capacitive transducer (1) comprising:a membrane having a movable part (4) provided with an electrode,a fixed plate (6) having a counter-electrode (8),a support structure (10) for the electrode and counter-electrode,
characterized in that said electret (30) has an electrically conductive first layer (32) embedded in an insulating material (34, 36). - Transducer according to claim 1, characterized in that it comprises charging means (46) for the electret (30) integrated within said plate (6).
- Transducer according to claim 1 or 2, characterized in that said plate (6) has a substrate (38) and in that said counter-electrode comprises a second electrically conductive layer (8) disposed on a face of the substrate (38).
- Transducer according to claim 3, characterized in that the electret (30) is disposed at the surface of said counter-electrode (8) and in that said first conductive layer (32) is disposed between a layer of insulating material (34) in contact with the counter-electrode (8) and termed the first insulating layer, and a layer of insulating material (36) facing the membrane termed the second insulating layer.
- Transducer according to one of claims 2 and 3, when the latter are dependendent on claim 2, characterized in that said charging means (46) include a third layer of electrically conductive material (50) disposed at the surface of said substrate (38) and which is isolated from the said counter-electrode (8) by a thickening (52) of the first insulating layer (34) and a zone of lesser thickness (56) provided in said first layer (34) over which extends the first conductive layer (32).
- Transducer according to one of claims 2 to 5, characterized in that it comprises control means (48) of the state of charge of the electret (30) integrated within said fixed plate (6).
- Transducer according to claim 6, characterized in that the control means (48) comprise a fourth electrically conductive layer (58) disposed at the surface of said substrate (38) and isolated from said counter-electrode (8) by a thickened zone (60) of the substrate (38).
- Transducer according to any one of the preceding claims, characterized in that said fixed plate (6) is connected to the membrane (4) by a plurality of arms (40a - 40h) extending from said plate (6).
- Transducer according to any one of claims 4 to 7 in combination with claim 8, characterized in that the second, third and fourth conductive layers (8, 50, 58) each extend at least along one of the suspension arms (40a - 40h) of said fixed plate (6).
- Transducer according to any one of the preceding claims, characterized in that the membrane (4) is connected to a frame (18) comprising contact windows (22a, 22b, 22c) for establishing a contact isolated from the electrode (4) and in that said plate (6) is fixed, by its arms (40a - 40h) and by means of insulating spacers (14), to said frame (8).
- Transducer according to one of claims 9 or 10, characterized in that the contact windows (22a, 22b, 22c) are disposed facing the arms (40a, 40b, 40c) having the second, third and fourth conductive layers (8, 50, 58).
- Transducer according to one of claims 10 or 11, characterized in that the frame comprises in addition another contact window (22d) facing one (40d) of said suspension arm (40a - 40h) to establish contact with the substrate (38).
- Transducer according to one of claims 10 to 12, characterized in that the membrane (4) and the frame (18) exhibit a monolithic structure.
- Transducer according to any one of the preceding claims, characterized in that said fixed plate (6) comprises a plurality of through holes (44) regularly distributed over the plate (6).
- Transducer according to any one of the preceding claims, characterized in that said support means (10) comprises a planar element provided with a cavity (12) extending facing said plate (6) and the edges of which (70) are fixed at the periphery to the membrane (4).
- Transducer according to claim 15, when the latter is dependent on claim 10, characterized in that said cavity (12) comprises a shoulder (68) extending at its periphery substantially facing said frame (18).
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
FR9210947A FR2695787B1 (en) | 1992-09-11 | 1992-09-11 | Integrated capacitive transducer. |
FR9210947 | 1992-09-11 |
Publications (2)
Publication Number | Publication Date |
---|---|
EP0587032A1 EP0587032A1 (en) | 1994-03-16 |
EP0587032B1 true EP0587032B1 (en) | 1998-04-08 |
Family
ID=9433486
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP93113955A Expired - Lifetime EP0587032B1 (en) | 1992-09-11 | 1993-09-01 | Integrated capacitive transducer |
Country Status (6)
Country | Link |
---|---|
US (1) | US5677965A (en) |
EP (1) | EP0587032B1 (en) |
JP (1) | JPH06217397A (en) |
DE (1) | DE69317833T2 (en) |
DK (1) | DK0587032T3 (en) |
FR (1) | FR2695787B1 (en) |
Families Citing this family (62)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0981823A1 (en) | 1996-04-18 | 2000-03-01 | California Institute Of Technology | Thin film electret microphone |
DE19638159C2 (en) * | 1996-09-18 | 2000-09-07 | Implex Hear Tech Ag | Fully implantable hearing aid for electrical hearing stimulation |
JP3604243B2 (en) * | 1996-11-27 | 2004-12-22 | 長野計器株式会社 | Capacitive transducer |
FI105880B (en) | 1998-06-18 | 2000-10-13 | Nokia Mobile Phones Ltd | Fastening of a micromechanical microphone |
US6088463A (en) * | 1998-10-30 | 2000-07-11 | Microtronic A/S | Solid state silicon-based condenser microphone |
AU5030100A (en) * | 1999-05-19 | 2000-12-05 | California Institute Of Technology | High performance mems thin-film teflon electret microphone |
US6522762B1 (en) | 1999-09-07 | 2003-02-18 | Microtronic A/S | Silicon-based sensor system |
US6661897B2 (en) * | 1999-10-28 | 2003-12-09 | Clive Smith | Transducer for sensing body sounds |
US6499348B1 (en) * | 1999-12-03 | 2002-12-31 | Scimed Life Systems, Inc. | Dynamically configurable ultrasound transducer with integral bias regulation and command and control circuitry |
JP3611779B2 (en) * | 1999-12-09 | 2005-01-19 | シャープ株式会社 | Electrical signal-acoustic signal converter, method for manufacturing the same, and electrical signal-acoustic converter |
FI115500B (en) | 2000-03-21 | 2005-05-13 | Nokia Oyj | Method of manufacturing a membrane detector |
US6842964B1 (en) | 2000-09-29 | 2005-01-18 | Tucker Davis Technologies, Inc. | Process of manufacturing of electrostatic speakers |
WO2002052893A1 (en) | 2000-12-22 | 2002-07-04 | Brüel & Kjær Sound & Vibration Measurement A/S | A highly stable micromachined capacitive transducer |
US6847090B2 (en) * | 2001-01-24 | 2005-01-25 | Knowles Electronics, Llc | Silicon capacitive microphone |
JP2002345088A (en) * | 2001-05-18 | 2002-11-29 | Mitsubishi Electric Corp | Pressure sensing device and manufacturing method for semiconductor substrate used for it |
KR100409273B1 (en) * | 2001-07-07 | 2003-12-11 | 주식회사 비에스이 | A chip microphone |
KR100409272B1 (en) * | 2001-07-07 | 2003-12-11 | 주식회사 비에스이 | A chip microphone |
US7298856B2 (en) * | 2001-09-05 | 2007-11-20 | Nippon Hoso Kyokai | Chip microphone and method of making same |
WO2003037212A2 (en) | 2001-10-30 | 2003-05-08 | Lesinski George S | Implantation method for a hearing aid microactuator implanted into the cochlea |
WO2003047307A2 (en) * | 2001-11-27 | 2003-06-05 | Corporation For National Research Initiatives | A miniature condenser microphone and fabrication method therefor |
US20040016120A1 (en) * | 2002-06-07 | 2004-01-29 | California Institute Of Technology | Method and resulting device for fabricating electret materials on bulk substrates |
WO2003105167A2 (en) * | 2002-06-07 | 2003-12-18 | California Institute Of Technology | Electret generator apparatus and method |
JP3492673B1 (en) * | 2002-06-21 | 2004-02-03 | 沖電気工業株式会社 | Manufacturing method of capacitance type acceleration sensor |
US6667189B1 (en) | 2002-09-13 | 2003-12-23 | Institute Of Microelectronics | High performance silicon condenser microphone with perforated single crystal silicon backplate |
US7142682B2 (en) * | 2002-12-20 | 2006-11-28 | Sonion Mems A/S | Silicon-based transducer for use in hearing instruments and listening devices |
DE10300063A1 (en) * | 2003-01-03 | 2004-07-22 | W.L. Gore & Associates Gmbh | Membrane for acoustic transducers |
WO2005050680A1 (en) | 2003-11-20 | 2005-06-02 | Matsushita Electric Industrial Co., Ltd. | Electret and electret capacitor |
JP4264103B2 (en) * | 2004-03-03 | 2009-05-13 | パナソニック株式会社 | Electret condenser microphone |
EP1722595A4 (en) * | 2004-03-05 | 2010-07-28 | Panasonic Corp | Electret condenser |
DE102004011149B3 (en) * | 2004-03-08 | 2005-11-10 | Infineon Technologies Ag | Microphone and method of making a microphone |
US7415121B2 (en) | 2004-10-29 | 2008-08-19 | Sonion Nederland B.V. | Microphone with internal damping |
FR2884101B1 (en) * | 2005-03-30 | 2007-06-29 | Merry Electronics Co Ltd | SILICON MICROPHONE CAPACITOR WITH MINIMAL DIAPHRAGM EFFORT |
TW200746868A (en) * | 2006-02-24 | 2007-12-16 | Yamaha Corp | Condenser microphone |
JP2007228345A (en) * | 2006-02-24 | 2007-09-06 | Yamaha Corp | Capacitor microphone |
JP4605470B2 (en) * | 2006-03-31 | 2011-01-05 | ヤマハ株式会社 | Condenser microphone |
TW200738028A (en) * | 2006-02-24 | 2007-10-01 | Yamaha Corp | Condenser microphone |
JP2007267049A (en) * | 2006-03-29 | 2007-10-11 | Yamaha Corp | Condenser microphone |
JP4737719B2 (en) * | 2006-02-24 | 2011-08-03 | ヤマハ株式会社 | Condenser microphone |
JP4737721B2 (en) * | 2006-03-10 | 2011-08-03 | ヤマハ株式会社 | Condenser microphone |
JP4770687B2 (en) * | 2006-03-29 | 2011-09-14 | ヤマハ株式会社 | Condenser microphone |
TW200746869A (en) * | 2006-03-29 | 2007-12-16 | Yamaha Corp | Condenser microphone |
JP4770692B2 (en) * | 2006-03-29 | 2011-09-14 | ヤマハ株式会社 | Condenser microphone |
JP4609363B2 (en) * | 2006-03-29 | 2011-01-12 | ヤマハ株式会社 | Condenser microphone and manufacturing method thereof |
ATE471635T1 (en) * | 2006-03-30 | 2010-07-15 | Sonion Mems As | SINGLE-CHIP ACOUSTIC MEMS TRANSDUCER AND MANUFACTURING METHOD |
CN101141832B (en) * | 2006-09-06 | 2011-04-20 | 歌尔声学股份有限公司 | Single membrane capacitance type microphone chip |
US20090136064A1 (en) * | 2007-09-28 | 2009-05-28 | Yamaha Corporation | Vibration transducer and manufacturing method therefor |
EP3796671A1 (en) * | 2008-06-30 | 2021-03-24 | The Regents of the University of Michigan | Piezoelectric mems microphone |
FR2936351B1 (en) * | 2008-09-25 | 2010-10-15 | Commissariat Energie Atomique | VARIABLE CAPACITY SYSTEM WITH FLEXIBLE DIELECTRIC. |
US8134215B2 (en) * | 2008-10-09 | 2012-03-13 | United Microelectronics Corp. | MEMS diaphragm |
TWI484834B (en) * | 2008-10-15 | 2015-05-11 | Htc Corp | Method and electronic device for driving a capacitance electro-acoustic transducer |
DE102009028177A1 (en) * | 2009-07-31 | 2011-02-10 | Robert Bosch Gmbh | Component having a micromechanical microphone structure and method for producing such a component |
TWI444052B (en) * | 2009-12-17 | 2014-07-01 | Ind Tech Res Inst | Capacitive transducer and fabrication method |
US8304846B2 (en) | 2009-12-31 | 2012-11-06 | Texas Instruments Incorporated | Silicon microphone with integrated back side cavity |
US8617960B2 (en) * | 2009-12-31 | 2013-12-31 | Texas Instruments Incorporated | Silicon microphone transducer |
US9013015B2 (en) * | 2010-01-11 | 2015-04-21 | Elmos Semiconductor Ag | Micro-electromechanical semiconductor component |
US9409763B2 (en) * | 2012-04-04 | 2016-08-09 | Infineon Technologies Ag | MEMS device and method of making a MEMS device |
FR3009907B1 (en) * | 2013-08-20 | 2015-09-18 | Commissariat Energie Atomique | DEVICE FOR CONVERTING THERMAL ENERGY IN ELECTRICAL ENERGY |
DE102013224718A1 (en) * | 2013-12-03 | 2015-06-03 | Robert Bosch Gmbh | MEMS microphone component and device having such a MEMS microphone component |
CN204046818U (en) | 2014-07-28 | 2014-12-24 | 瑞声声学科技(深圳)有限公司 | Capacitance MEMS (micro-electro-mechanical system) microphone |
US10277988B2 (en) * | 2016-03-09 | 2019-04-30 | Robert Bosch Gmbh | Controlling mechanical properties of a MEMS microphone with capacitive and piezoelectric electrodes |
CN207911008U (en) * | 2018-02-06 | 2018-09-25 | 瑞声声学科技(深圳)有限公司 | Mems microphone |
JP7240289B2 (en) * | 2019-08-13 | 2023-03-15 | 株式会社東芝 | MEMS element |
Family Cites Families (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
SE428081B (en) * | 1981-10-07 | 1983-05-30 | Ericsson Telefon Ab L M | ADDITION FRAME FOR AN ELECTRIC MICROPHONE |
US4524247A (en) * | 1983-07-07 | 1985-06-18 | At&T Bell Laboratories | Integrated electroacoustic transducer with built-in bias |
US4533795A (en) * | 1983-07-07 | 1985-08-06 | American Telephone And Telegraph | Integrated electroacoustic transducer |
NL8702589A (en) * | 1987-10-30 | 1989-05-16 | Microtel Bv | ELECTRO-ACOUSTIC TRANSDUCENT OF THE KIND OF ELECTRET, AND A METHOD FOR MANUFACTURING SUCH TRANSDUCER. |
US4906840A (en) * | 1988-01-27 | 1990-03-06 | The Board Of Trustees Of Leland Stanford Jr., University | Integrated scanning tunneling microscope |
US4993072A (en) * | 1989-02-24 | 1991-02-12 | Lectret S.A. | Shielded electret transducer and method of making the same |
US5208789A (en) * | 1992-04-13 | 1993-05-04 | Lectret S. A. | Condenser microphones based on silicon with humidity resistant surface treatment |
-
1992
- 1992-09-11 FR FR9210947A patent/FR2695787B1/en not_active Expired - Fee Related
-
1993
- 1993-09-01 DE DE69317833T patent/DE69317833T2/en not_active Expired - Lifetime
- 1993-09-01 EP EP93113955A patent/EP0587032B1/en not_active Expired - Lifetime
- 1993-09-01 DK DK93113955T patent/DK0587032T3/en active
- 1993-09-10 JP JP5225387A patent/JPH06217397A/en active Pending
-
1994
- 1994-09-20 US US08/309,329 patent/US5677965A/en not_active Expired - Lifetime
Also Published As
Publication number | Publication date |
---|---|
JPH06217397A (en) | 1994-08-05 |
DE69317833D1 (en) | 1998-05-14 |
DK0587032T3 (en) | 1999-02-08 |
DE69317833T2 (en) | 1998-11-12 |
US5677965A (en) | 1997-10-14 |
EP0587032A1 (en) | 1994-03-16 |
FR2695787B1 (en) | 1994-11-10 |
FR2695787A1 (en) | 1994-03-18 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
EP0587032B1 (en) | Integrated capacitive transducer | |
FR2864526A1 (en) | Electrostatic zipping type actuating device, has two electrodes located on same side with respect to movable electrode that has pivot positioned in lateral shift with respect to location of load | |
FR2571855A1 (en) | ABSOLUTE PRESSURE TRANSDUCER | |
LU84413A1 (en) | CAPACITIVE PRESSURE TRANSDUCER WITH ELECTROSTATICALLY LINKED SILICON | |
EP1562207A1 (en) | Bistable microelectromechanical system | |
EP1743349A2 (en) | Low consumption and low actuation voltage microswitch | |
EP1637498A1 (en) | MOS transistor with deformable gate | |
FR3045148A1 (en) | DETECTION DEVICE WITH SUSPENDED BOLOMETRIC MEMBRANES WITH HIGH ABSORPTION EFFICIENCY AND SIGNAL-TO-NOISE RATIO | |
FR2888394A1 (en) | CAPACITIVE DEVICE WITH OPTIMIZED CAPACITIVE VOLUME | |
FR2559900A1 (en) | CAPACITIVE PRESSURE SENSOR INSENSITIVE TO TEMPERATURE VARIATIONS | |
FR2946478A1 (en) | RESONATOR WITH VOLUME WAVES. | |
FR2717308A1 (en) | Protection device against overvoltages in integrated circuits. | |
EP0557216B1 (en) | Pressure microsensor | |
EP1543535A1 (en) | Electrostatically actuated low response time power commutation micro-switches | |
EP2149924B1 (en) | Organic transistor and method for manufacturing a dielectric layer of such a transistor | |
EP1434270B1 (en) | Photo-electric sensor device and method for making same | |
FR2705827A1 (en) | Improvements to the devices for manufacturing the electrets and to the electrets obtained. | |
EP0874379B1 (en) | Magnetic microswitch and method of making | |
FR2885410A1 (en) | Physical energy e.g. force, measuring device for e.g. tire, has rigid bar connected to deformable membrane and integrated to support, where electrodes disposed on membrane and support are moved when bar is stressed by force to be measured | |
WO2020136343A1 (en) | Semiconductor structure for digital and radiofrequency applications | |
EP1308972B1 (en) | Variable capacity device and method of manufacturing | |
EP2603448B1 (en) | Microelectromechanical system with air gap | |
EP0472481B1 (en) | High voltage semiconductor device having low leakage current | |
FR2848020A1 (en) | ELECTROSTATIC MICRO-SWITCH FOR LOW ACTUATING VOLTAGE COMPONENTS | |
EP4173033A1 (en) | Transistor with interdigital electrodes, comprising a gate terminal connected by a plurality of vertical vias to the gate electrodes |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
PUAI | Public reference made under article 153(3) epc to a published international application that has entered the european phase |
Free format text: ORIGINAL CODE: 0009012 |
|
AK | Designated contracting states |
Kind code of ref document: A1 Designated state(s): CH DE DK FR GB LI NL |
|
17P | Request for examination filed |
Effective date: 19940630 |
|
17Q | First examination report despatched |
Effective date: 19960826 |
|
GRAG | Despatch of communication of intention to grant |
Free format text: ORIGINAL CODE: EPIDOS AGRA |
|
GRAG | Despatch of communication of intention to grant |
Free format text: ORIGINAL CODE: EPIDOS AGRA |
|
GRAH | Despatch of communication of intention to grant a patent |
Free format text: ORIGINAL CODE: EPIDOS IGRA |
|
GRAH | Despatch of communication of intention to grant a patent |
Free format text: ORIGINAL CODE: EPIDOS IGRA |
|
GRAA | (expected) grant |
Free format text: ORIGINAL CODE: 0009210 |
|
AK | Designated contracting states |
Kind code of ref document: B1 Designated state(s): CH DE DK FR GB LI NL |
|
REG | Reference to a national code |
Ref country code: CH Ref legal event code: EP |
|
REF | Corresponds to: |
Ref document number: 69317833 Country of ref document: DE Date of ref document: 19980514 |
|
REG | Reference to a national code |
Ref country code: CH Ref legal event code: NV Representative=s name: ICB INGENIEURS CONSEILS EN BREVETS SA |
|
GBT | Gb: translation of ep patent filed (gb section 77(6)(a)/1977) |
Effective date: 19980625 |
|
REG | Reference to a national code |
Ref country code: DK Ref legal event code: T3 |
|
PLBE | No opposition filed within time limit |
Free format text: ORIGINAL CODE: 0009261 |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT |
|
26N | No opposition filed | ||
REG | Reference to a national code |
Ref country code: CH Ref legal event code: PL |
|
REG | Reference to a national code |
Ref country code: CH Ref legal event code: AEN Free format text: LE BREVET A ETE REACTIVE SELON LA DEMANDE DE POURSUITE DE LA PROCEDURE DU 10.08.2001 |
|
REG | Reference to a national code |
Ref country code: CH Ref legal event code: PUE Owner name: CENTRE SUISSE D'ELECTRONIQUE ET DE MICROTECHNIQUE Ref country code: CH Ref legal event code: NV Representative=s name: CSEM CENTRE SUISSE D'ELECTRONIQUE ET DE MICROTECHN |
|
REG | Reference to a national code |
Ref country code: GB Ref legal event code: IF02 |
|
REG | Reference to a national code |
Ref country code: GB Ref legal event code: 732E |
|
REG | Reference to a national code |
Ref country code: FR Ref legal event code: TP |
|
NLS | Nl: assignments of ep-patents |
Owner name: COLIBRYS S.A. |
|
REG | Reference to a national code |
Ref country code: CH Ref legal event code: NV Representative=s name: CABINET ROLAND NITHARDT CONSEILS EN PROPRIETE INDU |
|
REG | Reference to a national code |
Ref country code: CH Ref legal event code: PCAR Free format text: PATENTS & TECHNOLOGY SURVEYS SA;RUE DES TERREAUX 7 CASE POSTALE 2848;2001 NEUCHATEL (CH) |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: DK Payment date: 20090910 Year of fee payment: 17 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: NL Payment date: 20090915 Year of fee payment: 17 Ref country code: GB Payment date: 20090922 Year of fee payment: 17 Ref country code: CH Payment date: 20090923 Year of fee payment: 17 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: DE Payment date: 20090922 Year of fee payment: 17 |
|
REG | Reference to a national code |
Ref country code: NL Ref legal event code: V1 Effective date: 20110401 |
|
REG | Reference to a national code |
Ref country code: CH Ref legal event code: PFA Owner name: COLIBRYS SA Free format text: COLIBRYS SA#MALADIERE 83#2007 NEUCHATEL (CH) -TRANSFER TO- COLIBRYS SA#MALADIERE 83#2007 NEUCHATEL (CH) |
|
REG | Reference to a national code |
Ref country code: CH Ref legal event code: PL |
|
GBPC | Gb: european patent ceased through non-payment of renewal fee |
Effective date: 20100901 |
|
REG | Reference to a national code |
Ref country code: DK Ref legal event code: EBP |
|
REG | Reference to a national code |
Ref country code: FR Ref legal event code: ST Effective date: 20110531 |
|
REG | Reference to a national code |
Ref country code: DE Ref legal event code: R119 Ref document number: 69317833 Country of ref document: DE Effective date: 20110401 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: FR Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20100930 Ref country code: CH Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20100930 Ref country code: DE Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20110401 Ref country code: LI Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20100930 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: NL Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20110401 Ref country code: GB Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20100901 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: FR Payment date: 20091001 Year of fee payment: 17 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: DK Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20100930 |