EP2435797A2 - Sensor element - Google Patents
Sensor elementInfo
- Publication number
- EP2435797A2 EP2435797A2 EP10722997A EP10722997A EP2435797A2 EP 2435797 A2 EP2435797 A2 EP 2435797A2 EP 10722997 A EP10722997 A EP 10722997A EP 10722997 A EP10722997 A EP 10722997A EP 2435797 A2 EP2435797 A2 EP 2435797A2
- Authority
- EP
- European Patent Office
- Prior art keywords
- sensor
- substrate
- sensor element
- humidity
- active layer
- 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.)
- Ceased
Links
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
- G01D11/00—Component parts of measuring arrangements not specially adapted for a specific variable
- G01D11/24—Housings ; Casings for instruments
- G01D11/245—Housings for sensors
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L2924/00—Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
- H01L2924/0001—Technical content checked by a classifier
- H01L2924/0002—Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
Definitions
- the present invention relates to a sensor element for determining the temperature and / or the humidity and / or the flow rate and / or the gas concentration or the conductivity.
- the sensor element is an independent sensor for application to a printed circuit board.
- the sensor element can be used in liquid or gaseous media.
- sensor elements are frequently used which have coatings applied to a substrate in thin or thick film technology.
- contacting surfaces are applied to the substrate surface.
- the contacting surfaces are connected by wires in one of the usual methods with the conductor tracks of the printed circuit boards. Wires put in some
- An alternative possibility of contacting is to mount the substrate on the printed circuit board such that its active surface faces the printed circuit board so that the contacting surfaces come to lie on solder joints previously applied to the printed circuit board. For this purpose, however, it is necessary to provide corresponding recesses for the applied to the substrate active layer of the sensor element in the circuit board.
- Another method of contacting is two opposing ones
- the object of the invention is therefore to provide a sensor element which can be produced with any number of contacts in a time-saving and simple manner.
- a sensor element having at least one active layer, which is applied to one side of a substrate, in that the substrate has vias, and in that on the side remote from the at least one active layer side of the substrate terminal contacts are applied.
- the substrate is provided with plated-through holes.
- holes for example, by punctiform irradiation with a laser, are introduced into the substrate.
- the holes are provided in a thick film process with a paste, which preferably consists of AgPd. It goes without saying that other metallic materials can be used for this purpose. Under a plated through hole so is to understand a metallized hole.
- the plated-through holes can, for example, be of cylindrical design and, with a rectangular substrate base, are preferably in the corner regions of the substrate. In this way, the central area of the substrate is available for the coating with the active layer sensitive for the respective area of application of the sensor element.
- the active layer is to be understood as a layer which participates in the determination of the measurand to be determined.
- this may be, for example, a platinum meander, which was applied in a thin-film technique.
- the introduction of the plated-through holes in the substrate takes place before its coating with the active layer. In this way, damage or destruction of the active layer can be avoided.
- the plated-through holes furthermore offer the advantage that no connecting wires have to be mounted on the front side of the substrate, ie in the immediate vicinity of the active layer. This avoids the problem of flux residues on the active layer which may form on the substrate front during soldering.
- connection contacts are applied to one side of the substrate provided with the plated-through holes.
- the side of the substrate which carries the connection contacts is referred to below as the rear side of the substrate.
- the terminal contacts are one or more metallic materials, which are applied to the substrate in a thin or thick film technique or in a screen printing process.
- the application of the connection contacts can be done before or after the application of the active layer (s), as well as between two process steps.
- the active layer (s) is or are applied on the side of the substrate which is opposite the connection contacts.
- This active layer / active layer-carrying side of the substrate is referred to below as the front side of the substrate.
- the application of the active layer / layers is done in thin or thick film technology, wherein the layers can also be applied sequentially at intermediate curing phases.
- the application of layers such as passivations or intermediate layers can also be effected by a screen printing process and / or sintering processes.
- the sensor element according to the invention can be further processed by the favorable arrangement of the connection contacts on the back of the substrate in a pick-and-place process.
- This process in which components are automatically picked up and placed on a printed circuit board, is particularly space-saving and time-saving.
- the sensor element with the active layer are still placed on top of the circuit board, so no recess in the circuit board is required.
- An embodiment of the sensor element according to the invention provides that the substrate, which serves as a carrier of the active layers of the sensor element, has plated-through holes.
- the plated-through holes comprise metallized holes which extend continuously from one side of the substrate to the opposite side of the substrate.
- the plated-through holes do not have any additional coating in the interior, but applications are conceivable in which an additional coating, for example of a solderable, weldable or bondable material, is applied.
- an additional coating for example of a solderable, weldable or bondable material
- the active layer (s) deposited on the front side of the substrate is contacted from the back side of the substrate via the vias and the terminal contacts.
- the conductive material of the connection contacts is applied in one layer or in several layers on the substrate.
- connection contacts are solderable and / or weldable and / or bondable.
- An embodiment of the invention provides that the substrate consists of a proportion of between 96% and 99.6% of Al 2 O 3 .
- AI 2 O 3 is suitable because of a variety advantageous properties such as high thermal and chemical resistance. In addition, it has no semiconductor properties and is available at low cost.
- a further embodiment of the invention provides that the substrate consists essentially of ZrO 2. Since ZrO 2 has a low thermal conductivity, a ZrO 2 substrate ensures thermal decoupling of elements applied to the substrate, such as a heater and a temperature sensor.
- the substrate consists of silicon or a glass.
- Glass is particularly suitable as a substrate because of its high chemical resistance and low thermal conductivity.
- it has no semiconductor properties and also allows the application of structures of small size because of its low surface roughness. Since it is also available in many variants and cost, its use contributes to a cost-effective sensor element.
- Silicon has the advantage that in addition to active layers, electronic components can also be applied to the substrate.
- the sensor element is a humidity sensor for measuring the relative humidity.
- This is preferably a capacitive humidity sensor which has a moisture-sensitive layer.
- the moisture-sensitive layer is a polymer as a dielectric.
- the sensor element according to the invention is a gas or flow sensor based on a thermal principle.
- this gas or flow sensor has at least one meander-shaped platinum structure, wherein at least one of the platinum structures is designed as a heating element.
- the sensor element is a conductivity sensor which has at least two electrodes and a temperature sensor.
- the sensor element is a temperature sensor, which preferably has a meander-shaped platinum structure.
- the sensor element comprises a combination of at least two sensor types, for example temperature and humidity sensor or gas and flow sensor or temperature and flow sensor.
- the at least two sensor types are arranged side by side on the front side of the substrate or that at least two sensor types are arranged one above the other in a type of sandwich construction.
- a development of the sensor element according to the invention provides that the material of the plated-through holes is AgPd.
- AgPd is characterized by good resistance to high process temperatures and is also available at low cost. It goes without saying that other metallic materials instead of AgPd can form the material of the plated-through holes.
- FIG. 1 shows a combined temperature and humidity sensor according to the invention, wherein the active layers of the temperature sensor and the moisture sensor are arranged one above the other in a sandwich construction,
- FIG. 2 a schematically shows an advantageous way of installing a flow sensor in a pipeline
- FIG. 3 shows the back of a sensor element according to the invention in plan view.
- FIG. 1 shows an exemplary embodiment of a sensor element according to the invention. Shown are a temperature sensor 20 and a humidity sensor 30 in a sandwich construction. On the front side 11 of the substrate 1, a meander-shaped platinum resistance structure 2 for measuring the temperature in a thin-film technique is applied. In addition to platinum, other temperature-dependent metallic resistors are conceivable.
- the humidity is determined by the capacitive sensor 30.
- the capacitive sensor 30 includes a base electrode 4, a moisture-impermeable cover electrode 6 and a moisture-sensitive layer 5.
- the moisture-sensitive layer in this example is a polymer, which is the dielectric of the capacitive
- Moisture sensor 30 represents, and its dielectric constant is humidity-dependent, so that the electrical signal supplied by the humidity sensor 30 depends on the ambient humidity.
- the temperature sensor 20 is arranged in the immediate vicinity of the humidity sensor 30.
- the temperature sensor 20 and the humidity sensor 30 are arranged one above the other in a sandwich construction. This arrangement saves space compared to an arrangement of temperature sensor 20 and humidity sensor 30 side by side on the substrate 1.
- Between the resistor structure 2 of the temperature sensor 20 and the base electrode 4 of the humidity sensor 30 is passivated in the form of an intermediate layer 3 for electrical insulation.
- Base electrode 4 and the cover electrode 6 are guided along the side regions of the sandwich construction to the plated-through holes 71 in the substrate 1. Due to the insulation, no conductive contact between ground electrode 4 and Resistor structure 2 or between cover electrode 6 and ground electrode 4. Thus, it is possible to lead all to be contacted active layers of the sandwich construction to the terminal areas into which the vias 71 open. Via four plated-through holes 71 in the substrate 1, these terminal regions are led to the rear side 12 of the substrate 1. Because the
- Connection contacts 72 are arranged for connection to printed conductors on a printed circuit board on the back side 12 of the substrate 1, the active layers of the sandwich structure compared to the structure in conventional Kunststofftechniksart with a constant substrate area more area available.
- the rear side 12 of the substrate 1 with the local connection contacts 72 is described in the explanations to FIG.
- FIG. 2 shows a flow sensor 40 according to the invention.
- To determine the flow velocity of a medium here is a
- Hot-film anemometer used. This contains a heating element, which is cooled by the medium flowing past, so that the heating power, which is necessary to obtain a temperature determined by a temperature sensor arranged next to the heating element, is a direct measure of the flow velocity. Heating element and temperature sensor are advantageously arranged on the same substrate.
- the substrate material is preferably zirconium oxide. This substrate material has the advantage of a good thermal decoupling of heating element and temperature sensor with him, the heating element is formed in the flow sensor 40 shown here, as well as the temperature sensor in the form of a platinum structure 2 '.
- a glass layer 8 is applied between the substrate 1 and the platinum structure 2 '.
- the platinum structure 2 ' is of a passivation in the form of a moisture-impermeable Covering layer 9 surrounded.
- the substrate 1 is applied with the active sensor surface up on a printed circuit board.
- connection contacts 72 on the back 12 of the substrate 1 the connection between the circuit board and the sensor element is easy to implement.
- a thorough separation between active sensor surface on the front side 11 of the substrate and electronics on the rear side 12 of the substrate or the printed circuit board is made possible by the plated-through holes 71. This is particularly advantageous in flow sensors 40, which are used in liquids. However, this separation is also advantageous in the case of other sensor types, since, for example, moisture condensing on connecting leads can lead to measurement inaccuracies or even failures of the sensor.
- the flow sensor 40 according to the invention is introduced with the active sensor surface ahead via a recess in the wall of the tube in which the liquid flows in the tube interior and the recess sealed with a sealant.
- the connection contacts 72, as well as the entire electronics, are thus protected against moisture since they are not in contact with the medium inside the tube.
- Flow sensor 40 a further advantageous method of installation in a pipeline. This is shown schematically in Fig. 2a.
- the pipeline is shown only in a section and in cross section, with the representation of the rear wall was omitted for clarity.
- the medium flowing in the pipeline is indicated by the arrow.
- the wall 50 of the pipeline is in an area whose
- the flow sensor 40 is introduced with the active layer in the direction of the medium in the resulting depression, so that the sensors facing the medium while the electronics are approximately level with the outside of the pipeline.
- the sensor 40 is therefore not in direct contact with the medium, which avoids the occurrence of common problems in the flow measurement, such as contamination of the active sensor surface or corrosion and premature aging. Sealing to protect the electronics or coating the active layer with a protective layer are not necessary.
- a conductivity sensor comprises a ceramic substrate having at least two unpassivated electrodes and a passivated temperature sensor. Preferably, there are four electrodes.
- the temperature sensor is preferably designed in the form of a resistance structure on the substrate.
- the electrodes and the temperature sensor essentially consist of platinum.
- a gas sensor is similar to the structure of a flow sensor and comprises at least two resistance structures, in particular consisting of platinum, wherein at least one of the resistance structures forms a temperature sensor and a heating element.
- FIG. 3 shows the rear side 12 of a sensor element according to the invention facing away from the active layer / layers.
- the four plated-through holes are covered with four connection contacts 72.
- the connection contacts 72 are one or more layers of conductive material.
- the material of the connection contacts 72 can be soldered, so that the connection contacts 72 can be connected to corresponding contacts on a printed circuit board, for example in a low-resistance method.
- the connection contacts can also consist of a weldable material or a bondable material, so that the connection contacts 72 can be connected by welding or bonding with the contacts on the circuit board.
- the terminals 72 are preferably formed of nickel, chromium, aluminum, gold, palladium, titanium, tungsten or compounds of two or more of these materials.
- the plated-through holes consist of a metallic material, in particular, a silver-palladium compound has proven to be advantageous. LIST OF REFERENCE NUMBERS
Abstract
Description
Claims
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE102009026439A DE102009026439A1 (en) | 2009-05-25 | 2009-05-25 | Sensor element and method for producing such |
PCT/EP2010/056740 WO2010136351A2 (en) | 2009-05-25 | 2010-05-17 | Sensor element |
Publications (1)
Publication Number | Publication Date |
---|---|
EP2435797A2 true EP2435797A2 (en) | 2012-04-04 |
Family
ID=43049323
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP10722997A Ceased EP2435797A2 (en) | 2009-05-25 | 2010-05-17 | Sensor element |
Country Status (3)
Country | Link |
---|---|
EP (1) | EP2435797A2 (en) |
DE (1) | DE102009026439A1 (en) |
WO (1) | WO2010136351A2 (en) |
Families Citing this family (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE102011085310A1 (en) * | 2011-10-27 | 2013-05-02 | Innovative Sensor Technology Ist Ag | Method for determining intrinsic property e.g. concentration of ion in liquid medium, involves heating or cooling the portion of medium to predetermined temperature, using heating/cooling element |
DE102011089608A1 (en) * | 2011-12-22 | 2013-06-27 | Horst Siedle Gmbh & Co. Kg | Housing part for an electrical sensor and method for producing the housing part |
DE102012106939A1 (en) | 2012-07-30 | 2014-01-30 | Innovative Sensor Technology Ist Ag | Device for capacitive determination of moisture content of surrounding medium, has electronic unit which is provided to charge sensor element with excitation signal with frequency and to receive measuring signal |
DE102015114314A1 (en) * | 2015-08-28 | 2017-03-02 | Innovative Sensor Technology Ist Ag | Method for producing a temperature sensor |
DE102016117088A1 (en) | 2016-09-12 | 2018-03-15 | Innovative Sensor Technology Ist Ag | Apparatus for the capacitive determination of the moisture content and method for operating the apparatus |
DE102017130950A1 (en) * | 2017-12-21 | 2019-06-27 | Innovative Sensor Technology Ist Ag | Thermal flow sensor for determining the temperature and flow rate of a flowing medium |
JP6965995B2 (en) * | 2018-07-04 | 2021-11-10 | 株式会社村田製作所 | Composite sensor |
DE102019127915A1 (en) * | 2019-10-16 | 2021-04-22 | Tdk Electronics Ag | Sensor element and method for producing a sensor element |
Family Cites Families (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DD275538A1 (en) * | 1988-09-12 | 1990-01-24 | Feutron Greiz Veb | METHOD FOR PRODUCING A CAPACITIVE SORPTION HUMID SENSOR |
DE3834987A1 (en) * | 1988-10-14 | 1990-04-19 | Bosch Gmbh Robert | SENSOR ELEMENT FOR LIMIT CURRENT SENSORS FOR DETERMINING THE (LAMBDA) VALUE OF GAS MIXTURES |
DE3941837C2 (en) * | 1989-12-19 | 1994-01-13 | Bosch Gmbh Robert | Resistance sensor for detecting the oxygen content in gas mixtures and process for its production |
DE102006021432A1 (en) * | 2005-06-11 | 2006-12-14 | Moos, Ralf, Prof. Dr. Ing. | Integration of pre-sintered, substrate ceramics with low temperature co-fired ceramics (LTTC)-foils, involves joining substrate ceramic with green zero-shrinkage, LTTC foil |
DE102006033856B3 (en) * | 2006-07-21 | 2008-02-21 | Georg Bernitz | Temperature measuring sensor and method for its production |
-
2009
- 2009-05-25 DE DE102009026439A patent/DE102009026439A1/en not_active Withdrawn
-
2010
- 2010-05-17 EP EP10722997A patent/EP2435797A2/en not_active Ceased
- 2010-05-17 WO PCT/EP2010/056740 patent/WO2010136351A2/en active Application Filing
Non-Patent Citations (2)
Title |
---|
None * |
See also references of WO2010136351A2 * |
Also Published As
Publication number | Publication date |
---|---|
WO2010136351A2 (en) | 2010-12-02 |
WO2010136351A3 (en) | 2011-08-11 |
DE102009026439A1 (en) | 2010-12-09 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
EP2435797A2 (en) | Sensor element | |
EP1756537B1 (en) | Temperature sensor and method for the production thereof | |
EP2089696B1 (en) | Method of manufacturing a sensor and corresponding sensor | |
EP0972288B1 (en) | Method for producing a sensor arrangement for measuring temperature | |
EP3615903B1 (en) | Sensor for measuring a spatial temperature profile and method for producing a sensor unit | |
DE102012211924B4 (en) | Semiconductor module having a shunt resistor integrated in a terminal lug and method for detecting a current flowing through a load terminal of a semiconductor module | |
EP0801150A2 (en) | Electronic component | |
DE102016101249A1 (en) | Sensor element and method for producing a sensor element | |
WO2006005332A2 (en) | Device for determining the characteristics of a gas | |
DE19941420A1 (en) | Electrical resistor, such as temperature dependent resistor used as measuring resistor has conducting path with connecting contact fields arranged on an electrically insulating surface of substrate | |
EP2083262B1 (en) | Resistive hydrogen sensor | |
WO2007131648A2 (en) | Electrical sensor production and use thereof | |
WO2018095709A1 (en) | Current measuring device | |
EP3421981B1 (en) | Sensor device for measuring humidity and temperature | |
DE19843471A1 (en) | Pressure identification system with sensor body and housing arranged outside body | |
DE102004047725A1 (en) | sensor device | |
EP1204301B1 (en) | Arrangement for forming an input circuit for recording and processing an electrical signal | |
DE3818191C2 (en) | ||
WO2021037611A1 (en) | Fill level detection by means of heating structures | |
DE102019131306A1 (en) | Sensor element and method for producing a sensor element | |
WO2008145512A2 (en) | Contact element of device for determining and/or monitoring a process variable | |
DE102006060978B4 (en) | SMD temperature measuring element and device | |
DE19802296A1 (en) | Thermometer probe for measuring surface temperatures with electronic temperature-sensitive sensor element | |
DE102017104162A1 (en) | Sensor element and thermal flow sensor for determining a physical size of a measuring medium | |
DE10022210A1 (en) | Measuring system used for controlling the hydrogen ion activity comprises an indicator electrode, an outer electrode and an earthing electrode arranged together on one side |
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 |
|
17P | Request for examination filed |
Effective date: 20111021 |
|
AK | Designated contracting states |
Kind code of ref document: A2 Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO SE SI SK SM TR |
|
DAX | Request for extension of the european patent (deleted) | ||
17Q | First examination report despatched |
Effective date: 20121025 |
|
RAP1 | Party data changed (applicant data changed or rights of an application transferred) |
Owner name: INNOVATIVE SENSOR TECHNOLOGY IST AG |
|
REG | Reference to a national code |
Ref country code: DE Ref legal event code: R003 |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: THE APPLICATION HAS BEEN REFUSED |
|
18R | Application refused |
Effective date: 20181103 |