WO2021151411A1 - Capteur de pression - Google Patents

Capteur de pression Download PDF

Info

Publication number
WO2021151411A1
WO2021151411A1 PCT/DE2021/000013 DE2021000013W WO2021151411A1 WO 2021151411 A1 WO2021151411 A1 WO 2021151411A1 DE 2021000013 W DE2021000013 W DE 2021000013W WO 2021151411 A1 WO2021151411 A1 WO 2021151411A1
Authority
WO
WIPO (PCT)
Prior art keywords
layer
pressure sensor
sensor according
conductor tracks
areas
Prior art date
Application number
PCT/DE2021/000013
Other languages
German (de)
English (en)
Inventor
Arne Kentner
Original Assignee
EMSU GmbH
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 EMSU GmbH filed Critical EMSU GmbH
Priority to EP21710876.0A priority Critical patent/EP4133248A1/fr
Priority to DE112021000780.7T priority patent/DE112021000780A5/de
Publication of WO2021151411A1 publication Critical patent/WO2021151411A1/fr

Links

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
    • G01L1/00—Measuring force or stress, in general
    • G01L1/18—Measuring force or stress, in general using properties of piezo-resistive materials, i.e. materials of which the ohmic resistance varies according to changes in magnitude or direction of force applied to the material
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
    • G01L1/00—Measuring force or stress, in general
    • G01L1/20—Measuring force or stress, in general by measuring variations in ohmic resistance of solid materials or of electrically-conductive fluids; by making use of electrokinetic cells, i.e. liquid-containing cells wherein an electrical potential is produced or varied upon the application of stress
    • G01L1/205—Measuring force or stress, in general by measuring variations in ohmic resistance of solid materials or of electrically-conductive fluids; by making use of electrokinetic cells, i.e. liquid-containing cells wherein an electrical potential is produced or varied upon the application of stress using distributed sensing elements
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
    • G01L1/00—Measuring force or stress, in general
    • G01L1/20—Measuring force or stress, in general by measuring variations in ohmic resistance of solid materials or of electrically-conductive fluids; by making use of electrokinetic cells, i.e. liquid-containing cells wherein an electrical potential is produced or varied upon the application of stress
    • G01L1/22—Measuring force or stress, in general by measuring variations in ohmic resistance of solid materials or of electrically-conductive fluids; by making use of electrokinetic cells, i.e. liquid-containing cells wherein an electrical potential is produced or varied upon the application of stress using resistance strain gauges
    • G01L1/2287—Measuring force or stress, in general by measuring variations in ohmic resistance of solid materials or of electrically-conductive fluids; by making use of electrokinetic cells, i.e. liquid-containing cells wherein an electrical potential is produced or varied upon the application of stress using resistance strain gauges constructional details of the strain gauges

Definitions

  • the invention relates to a pressure sensor which has a bottom layer and a flexible cover layer.
  • the bottom layer comprises first conductor tracks and insulation surfaces which cover the first conductor tracks.
  • the bottom layer also includes second conductor tracks over the insulation layers.
  • the insulation areas are also referred to as dielectric areas.
  • Such a pressure sensor is known, for example, from US Pat. No. 10,359,326 B2.
  • Such pressure sensors consist of several layers.
  • the lower layer is referred to as the bottom layer, above which follows a sequence of conductive layers, resistance layers and non-conductive layers that varies depending on the structure.
  • Silver-based inks for example, are used as conductive layers, and carbon-based inks, for example, can be used as resistance layers.
  • a force-sensing resistor is a brand name registered in the USA for a measuring element from Interlink Electronics that changes electrical resistance under the action of force or pressure.
  • An FSR consists of a sandwich of two plastic films. One is coated on the inside with FSR ink, a paste containing graphite, the other with two electrically conductive contact grids nested in a comb shape. However, these are electrically isolated from each other and have external connections.
  • the two foils are connected to one another by means of a double-sided adhesive layer. This adhesive layer also ensures that the coated active areas of the foils practically do not touch each other in the unloaded state. Only when pressure or force is applied to the sandwich are the contact grids electrically connected to one another via the FSR ink and the electrical resistance of the structure can be measured at the external connections.
  • the pressure sensors based on FSR ink are mostly manufactured in a “shunt mode” or a “through mode”.
  • the through-mode requires electrically conductive tracks on both substrates that are aligned with one another.
  • the shunt mode does not require any conductor tracks on the top.
  • the measurement characteristics of the two modes are different because the change in resistance is mainly due to a change in the contact surface.
  • a change in the resistance in the FSR material is only very slight and can occur with a positive or negative sign depending on the concentration of the conductive particles.
  • the contact resistance between FSR materials or an FSR material and a conductor always decreases with increasing pressure.
  • the contact resistance in shunt mode (FSR conductor contact resistance) is very small compared to through-mode, since the resistance ink hits the conductor tracks (silver, copper, etc.) directly.
  • the change in resistance after activation is smaller than in through-mode.
  • the through-mode can have a very low resistance up to a quasi short circuit, while the shunt-mode usually has a constant resistance (FSR bulk) through the layer on the top.
  • FSR bulk constant resistance
  • shunt mode In practical use, either shunt mode or through mode is used, depending on the requirements.
  • the invention is based on the object of further developing a generic pressure sensor in such a way that it combines advantages of the shunt mode with advantages of the through mode.
  • a measuring point comprises at least one resistance area of the driver conductor track, at least one resistance area of the readout conductor track, and at least one upper resistance area on the cover layer.
  • the pressure sensor according to the invention requires two contacts, which makes it difficult to measure weights precisely.
  • this disadvantage can be mitigated by using thicker cover layers or partially rigid structures.
  • the layer thickness of the (cover) film be greater is than the distance between the first and second conductor tracks.
  • conductor tracks are usually crossed by applying conductive material to the top and bottom layers. At these crossing points, FSR material is then applied to both sides.
  • the top layer and the bottom layer must be in contact and therefore be precisely aligned with one another.
  • the various process steps must be carried out for both shifts. Because of the repeated application and because of the shrinkage of the substrates during curing in the oven or due to UV radiation, larger tolerances must be provided or higher rejects from production are expected.
  • only certain substrates can be used for the top layer, since both the highly conductive ink and an FSR ink must show good properties on this substrate. Flexible substrates in particular therefore pose a challenge for low-resistance conductor tracks.
  • the pressure sensor according to the invention allows a layout with conductor tracks crossing one another on the bottom layer and parallel FSR material tracks.
  • the connection between the conductor tracks is achieved by orthogonally arranged FSR tracks on the cover layer.
  • the orientation and size of the FSR lanes are not critical. This simplifies the production of the cover layer and the subsequent joining of the layers.
  • Different cover materials can be used, since the shrinkage has no effect on the function of the pressure sensor and only the resistance ink has to be printed on the substrate.
  • the reduced requirements also allow an increased resolution in the layout and, given the given parameters, less scrap.
  • the conductor tracks can be vapor-deposited, sintered or electroplated. However, it is particularly advantageous if the first and / or second conductor tracks are printed, since the printing of conductor tracks can be better combined with the production of the resistance areas.
  • first and / or second conductor tracks can also be implemented, at least in part, by an etched, milled or punched circuit board. This enables standardized production processes to be used.
  • a conductor track on the bottom layer has an elongated pad which runs parallel to another conductor track.
  • the bottom layer can also have several elongated pads.
  • the top layer and the bottom layer consist of different substrates and / or layer structures. This enables a very flexible top layer with a dimensionally stable bottom layer. The flexibility of the top layer improves the sensor behavior, the bottom layer enables production with smaller tolerances or better yield.
  • the cover layer has a laminate of a thin, harder layer and a soft, thicker layer. The thinner, harder layer serves to protect the sensor from external impairments such as abrasion and scratches. The softer layer allows the cover layer to be deformed and thus an improved print image. Due to the thin layer thickness of the hard layer, it is flexible enough.
  • Sinking in facilitates the measurement of the weight and the imprints of objects, since the contact surface is enlarged and the number of actuated measuring points is increased.
  • a thin hard layer without the softer layer impairs the measuring behavior of the sensor, since objects on the sensor can only be detected from a few measuring points.
  • the resistance area on the cover layer can be used as the resistance area on the cover layer.
  • a single area that covers the entire surface would mean that, on the one hand, no template is required, but, on the other hand, more material is required.
  • the bottom layer has first conductor tracks arranged orthogonally to one another and the resistance areas on the cover layer are arranged orthogonally to the resistance areas on the bottom layer.
  • the upper resistance areas can be shaped, for example, as solid lines or dashed lines.
  • the lower resistive ink areas are designed as contact electrodes arranged parallel to the second conductor tracks.
  • the resistance ink can completely cover the first and second conductive paths.
  • the lower resistance areas of the first and second conductor tracks should be separated from one another. It is advantageous if the cover layer has a layer thickness that is greater than the distance between the measuring points. In practice, the layer thickness is also greater than the distance between the pads. This ensures a flattening of pressure peaks and a distribution of the pressure peaks over several measuring points.
  • the top layer has a Shore hardness ⁇ 75A.
  • the cover layer can also have a laminate and then the entire laminate or a layer of the laminate can have this hardness.
  • a thin hard layer can have a hardness greater than 75A.
  • the cover layer should be flexible and thick enough to allow objects to sink in if the pressure sensors are to be used to check whether objects are standing on it. It is therefore proposed that the cover layer have a thickness of more than 0.5 mm.
  • the bottom layer can be flexible or rigid. It is advantageous if it is less flexible than the top layer. A harder bottom layer is advantageous for production, since it usually increases the dimensional stability. For example, reinforcing materials such as glass or carbon fiber fabrics can be incorporated into the soil layer.
  • a particularly advantageous embodiment provides that the cover layer has stiffening in some areas.
  • the cover layer is therefore not equally flexible throughout, but rather has a stiffening that is created by a thickness that is changed in some areas or the stability of the material being changed in some areas.
  • This goal can also be achieved in that the cover layer has a reduced layer thickness in some areas.
  • the resistance area can have several resistance layers placed one on top of the other.
  • Figure 1 schematically the structure according to the invention in plan view and as a section with a corresponding circuit diagram
  • Figure 2 schematically shows a known structure in through-mode in plan view and as a section along line A with circuit diagram
  • FIG. 3 schematically shows a known structure in shunt mode along line B with a circuit diagram
  • FIG. 4 schematically a first layer of a pressure sensor
  • Figure 5 shows schematically the first layer with additional conductor tracks as a driver
  • FIG. 6 shows the layer structure shown in FIG. 5 with an additional FSR layer
  • FIG. 7 shows the layer structure shown in FIG. 6 with an additional cover layer
  • FIG. 8 the layer structure shown in FIG. 7, slightly enlarged, with the ideal arrangement of the conductor tracks
  • FIG. 9 shows the layer structure shown in FIG. 8 after a material shrinkage
  • FIG. 10 shows the layer structure shown in FIG. 8 after a small rotation when joining the sensors.
  • the individual elements are not shown true to scale.
  • the height is significantly less than the width, since in practice the structures are about 30 ⁇ m high and about 3 mm wide.
  • a bottom layer 2 which can also be referred to as the base layer
  • first readout conductor tracks 4 and second driver conductor tracks 5 are each covered with the dielectric surface 6. This creates lower resistance areas 8, 9.
  • the cover layer 3 has an upper resistance area 10, which connects the lower resistance areas 8, 9 when the cover layer is applied.
  • the cover layer can cover, connect or overlap the readout and driver conductor tracks.
  • FIGS. 4 to 7 show, in FIG. 4, first conductor tracks 4, dielectric areas 6 and pads 7 of the first conductor tracks.
  • second conductor tracks 5 are additionally shown, and in FIG. 6 lower resistance areas 8 above the pads of the first conductor tracks 4 and lower resistance areas 9 above the second conductor tracks 5 are also shown.
  • FIG. 7 then additionally shows upper resistance areas 10.
  • FIGS. 8 to 10 it is shown that a slight shrinkage and also a slight twist when applying the layers does not necessarily have to impair the function of the pressure sensor.

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Force Measurement Appropriate To Specific Purposes (AREA)

Abstract

L'invention concerne un capteur de pression qui présente une couche de fond et une couche de recouvrement souple, la couche de fond présentant de premières pistes conductrices, des surfaces diélectriques recouvrant au moins par endroits ces pistes conductrices et de deuxièmes pistes conductrices situées au-dessus.
PCT/DE2021/000013 2020-01-30 2021-01-29 Capteur de pression WO2021151411A1 (fr)

Priority Applications (2)

Application Number Priority Date Filing Date Title
EP21710876.0A EP4133248A1 (fr) 2020-01-30 2021-01-29 Capteur de pression
DE112021000780.7T DE112021000780A5 (de) 2020-01-30 2021-01-29 Drucksensor

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE102020000604.3 2020-01-30
DE102020000604.3A DE102020000604A1 (de) 2020-01-30 2020-01-30 Drucksensor

Publications (1)

Publication Number Publication Date
WO2021151411A1 true WO2021151411A1 (fr) 2021-08-05

Family

ID=74867368

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/DE2021/000013 WO2021151411A1 (fr) 2020-01-30 2021-01-29 Capteur de pression

Country Status (3)

Country Link
EP (1) EP4133248A1 (fr)
DE (2) DE102020000604A1 (fr)
WO (1) WO2021151411A1 (fr)

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20010008389A1 (en) * 1998-09-11 2001-07-19 Bogdan Serban Force sensor
US20050262949A1 (en) * 2004-05-31 2005-12-01 Novineon Healthcare Technology Partners Gmbh Tactile instrument
US20140076063A1 (en) * 2012-09-17 2014-03-20 Tk Holdings Inc. Single layer force sensor
US10359326B2 (en) 2015-09-24 2019-07-23 Nippon Mektron, Ltd. Pressure sensor capable of suppressing dispersion in the initial load of pressure

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4314227A (en) 1979-09-24 1982-02-02 Eventoff Franklin Neal Electronic pressure sensitive transducer apparatus
US20140374230A1 (en) 2013-06-25 2014-12-25 Microsoft Corporation Pressure sensitive keys with a single-sided direct conduction sensor

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20010008389A1 (en) * 1998-09-11 2001-07-19 Bogdan Serban Force sensor
US20050262949A1 (en) * 2004-05-31 2005-12-01 Novineon Healthcare Technology Partners Gmbh Tactile instrument
US20140076063A1 (en) * 2012-09-17 2014-03-20 Tk Holdings Inc. Single layer force sensor
US10359326B2 (en) 2015-09-24 2019-07-23 Nippon Mektron, Ltd. Pressure sensor capable of suppressing dispersion in the initial load of pressure

Also Published As

Publication number Publication date
DE102020000604A1 (de) 2021-08-05
DE112021000780A5 (de) 2022-12-01
EP4133248A1 (fr) 2023-02-15

Similar Documents

Publication Publication Date Title
DE2524437C3 (de) Schalttafelstruktur einer kapazitiv gekoppelten Tastatur
DE2912049C2 (fr)
DE3013129C2 (de) Detektorvorrichtung für die X- und Y-Koordinaten von Eingabepunkten
DE69922673T2 (de) Kraftsensor
DE3406093A1 (de) Tastfuehler fuer eine roboter-greifvorrichtung oder aehnlichem
EP2174328A2 (fr) Composant multicouche électrique
DE112013004512T5 (de) Einzelschicht-Kraftsensor
DE8407989U1 (de) Dateneingabetafel zum Eingeben von Daten in einen Computer
DE3642780A1 (de) Detektormatte und verfahren zu ihrer herstellung
DE2623229A1 (de) Membranschalter
CH672377A5 (fr)
WO2008058531A1 (fr) Ensemble composant
DE202017006511U1 (de) Touchsensor und kapazitives Touchsensorsystem
EP1105942B1 (fr) Dispositif d'etablissement de contact, en particulier pour l'etablissement de contact entre des composants electriques et des supports de circuit, ainsi que procede de fabrication dudit dispositif
EP2646953A1 (fr) Support de données portable
DE3643124C2 (fr)
DE10016427C2 (de) Sensor, insbesondere Feuchtesensor, und Verfahren zur Herstellung desselben
WO2021151411A1 (fr) Capteur de pression
DE202016008592U1 (de) Sensor
DE102011004543B4 (de) Widerstand, Leiterplatte und elektrisches oder elektronisches Gerät
DE102007004893B4 (de) Piezoelektrischer Vielschichtaktor und Verfahren zu seiner Herstellung
DE102012112445A1 (de) Mehrschichtkörper zur Bereitstellung einer Tastfeldfunktionalität
DE102004046629B4 (de) Verfahren zum Herstellen eines Bauelementes mit einem gedruckten Schaltkreis
WO2010130370A1 (fr) Capteur à couche épaisse structuré par photolithographie
WO2020229696A1 (fr) Dispositif piézoélectrique

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 21710876

Country of ref document: EP

Kind code of ref document: A1

DPE1 Request for preliminary examination filed after expiration of 19th month from priority date (pct application filed from 20040101)
REG Reference to national code

Ref country code: DE

Ref legal event code: R225

Ref document number: 112021000780

Country of ref document: DE

32PN Ep: public notification in the ep bulletin as address of the adressee cannot be established

Free format text: FESTSTELLUNG EINES RECHTSVERLUSTS NACH REGEL 112(1) EPUE (EPA FORM 1205A VOM 13/10/2022)

ENP Entry into the national phase

Ref document number: 2021710876

Country of ref document: EP

Effective date: 20220830