KR20180034444A - Apparatus for detecting at least one characteristic of a medium and method for adjusting the signal of the apparatus - Google Patents

Abstract

The invention relates to an apparatus (110) for detecting at least one characteristic of a medium. The apparatus 110 includes at least one substrate 112; At least two electrical contacts (114); And at least one balancing resistor (116). The balancing resistor 116 electrically connects the two electrical contacts 114 along the connecting line 118 to allow current to flow between the electrical contacts 114 in parallel with the connecting line 118. The balancing resistor 116 extends across the connecting line 118 in the extending direction 120 and has a width B which varies along the extending direction 120.

Description

Apparatus for detecting at least one characteristic of a medium and method for adjusting the signal of the apparatus

The invention relates to an apparatus for detecting at least one characteristic of a medium and a method for adjusting the signal of the apparatus. Such devices are used, for example, in automotive technology, in particular for detecting at least one measurement variable, for example for detecting at least one characteristic of a fluid medium. For example, a sensor device, particularly a ceramic sensor device, such as a lambda probe and / or a NOx sensor, is referred to herein. The invention can in principle also be used in other fields of application.

Known devices for detecting at least one characteristic of a medium have a number of technical challenges. In general, there is a need for adjustment of the system resistance to the sensor element, or so-called adjustment of the sensor device for adjusting or calibrating the signal level, which is generally the same meaning. In addition, there is a growing demand for a method that can ensure improvement in adjustment accuracy and process reliability.

It is an object of the present invention to provide an apparatus for detecting at least one characteristic of a medium and a method for adjusting the signal of the apparatus, which at least largely solves the aforementioned technical challenges of the known apparatus and method.

According to the present invention, an apparatus for detecting at least one characteristic of a medium and a method for adjusting the signal of said apparatus, which at least substantially avoids the aforementioned problems of the known apparatus and method, is proposed.

An apparatus for detecting at least one characteristic of a medium includes at least one substrate, at least two electrical contacts and at least one balancing resistor. At least two electrical contacts and balancing resistors may be provided on the substrate, for example. As will be described in more detail below, the substrate may be, for example, a ceramic substrate.

The balancing resistor electrically connects the two electrical contacts along at least one connection line so that current can flow through the electrical contacts as it expands relative to the connection line. The balancing resistance has a width B extending across the connection line, i.e. at an angle other than 0 ° or 180 ° to the connection line, in particular in the extension direction perpendicular to the connection line. The width B varies along the extension direction. The angle between the extension direction and the connecting line may be 70 ° to 110 °, preferably 80 ° to 100 °, particularly preferably 90 °.

In the context of the present invention, "substrate" means an arbitrarily formed element having a long shape and thickness, the size of the element being such that the lateral dimension exceeds the thickness of the element, for example by a factor of 5, Lt; RTI ID = 0.0 > 10 < / RTI > or more preferably by a factor of 20.

The substrate may be, for example, a ceramic substrate. The substrate may comprise, for example, aluminum oxide and / or at least one other metal oxide. The substrate may be an electrically insulating substrate in particular, so that current flow between the electrical contacts by the substrate can be made or only negligible current flow can be made. The substrate may be rigid, but may be wholly or partly flexible or deformed, for example, by the substrate being formed completely or partially as a film, for example as a ceramic film.

The expression "balancing resistance" in the context of the present invention refers to any electrical resistance that can be changed by external intervention. In particular, the device can be designed so that at least one sensor signal can be tapped or detected through a balancing resistor, and a change in signal due to a change in balancing resistance can occur, It can be done by change. Adjustments may be made, in particular, by operating the device under conditions in which the device is precisely defined, and the balancing resistance is varied until the signal corresponds to a setting signal that meets the precisely defined conditions. In principle, other adjustments are possible. The change in the balancing resistance can be performed by a cut, particularly a laser cut, in particular as described in more detail below, so that preferably at least one surface of the balancing resistance can be accessible to the laser beam.

The balancing resistance may include at least one cross sectional contraction along the extension direction. The electrical contacts may contact the balancing resistor, particularly the opposite surface on the cross-sectional contraction portion. The width B of the balancing resistance may be smaller in the cross-sectional contraction portion than in at least one region other than the cross-sectional contraction portion. The balancing resistance may have a width B1 in at least one first region and a width B2 different from the width B1 in at least one second region. In particular, the width B1 may correspond to the width B of the cross-sectional contraction portion, and the second region may correspond to a region other than the cross-sectional contraction portion. In this case, B1 may be less than B2. In particular, the length of the balancing resistor along the extension direction may exceed the width B1 by a factor of at least 1.5, preferably by a factor of 2, particularly preferably by a factor of 3. Other embodiments are also possible in principle.

The expressions "first" and "second" regions are used to denote the order or ranking and for example the possibility of providing different types of first regions and different types of second regions, Should be regarded as a pure expression. Further, additional areas, for example one or more third areas, may be provided.

The balancing resistance may include a boundary in at least one transition to the sectioned constriction. The boundary may extend diagonally relative to the connecting line. Alternatively or additionally, the boundary can extend in a curved line. Alternatively or additionally, the border can extend angled. The balancing resistance may have a shape selected from the group consisting of a bone shape, a dumbbell shape, and a columnar shape with a widened end. Other shapes are possible. The balancing resistors may have, for example, a bony or dumbbell shape with a narrow internal and widened end, and at least two electrical contacts are in contact with the narrow interior, e.g.

The balancing resistance may have a different shape from the rectangular shape in particular. For example, the shape of the balancing resistor may be symmetrical, in particular mirror symmetry, with respect to the extension direction and / or the axis of symmetry extending parallel to or extending in the extension direction. Axial symmetry may also be given for additional symmetry axes extending perpendicular to the direction of extension.

The balancing resistance may comprise at least one exposed surface accessible to the laser beam.

The balancing resistance can be a thick film resistance in particular. The term "thick film resistor" refers in principle to the electrical resistance produced using thick film technology. In particular, the balancing resistance can be provided by a screen printing process. The thick film resistor may be made, for example, entirely or partially as at least one conductive paste. The paste may especially be a ceramic or a conductive paste. In particular, a plurality of different conductive pastes with different resistance values can be provided. The at least one conductive paste is first provided on the substrate as a raw material, and can be burned out by the sintering process. In particular, the balancing resistance can have a high resistance value, in particular a high termination resistance value of the balancing resistor after performing the method of adjusting the signal, which is described in detail below.

The balancing resistance may comprise at least one protective layer. The expression "protective layer" refers in principle to any layer designed to protect the balancing resistance from external influences, in particular from moisture. The protective layer can be produced by thick film technology, in particular by a screen printing process. The protective layer may comprise, for example, a polymeric material. In particular, the protective layer may comprise an encapsulating material, in particular an encapsulating material, including glass. The encapsulation material may be configured to form a protective layer and / or an insulating layer, in particular on the balancing resistance. In principle, other materials are also possible. For example, the thickness of the protective layer is in the range of 2 탆 to 50 탆, preferably in the range of 5 탆 to 20 탆, more preferably in the range of 7 탆 to 13 탆. In principle, other dimensions are possible.

The expression "electrical contact" in the context of the present invention means, in principle, a part made of an electrically conductive material and mounted on a substrate. The electrical contacts may for example be made of a silver compound, preferably silver platinum or particularly preferably silver palladium. Other materials are possible. For example, the thickness of the electrical contact is in the range of 5 탆 to 50 탆, preferably in the range of 7 탆 to 20 탆, particularly preferably in the range of 11 탆 to 17 탆. In principle, other dimensions are possible. The electrical contacts can be provided to the substrate, for example by thick film technology, in particular by a screen printing process. In principle, other processes may be used. The electrical contacts have a two-dimensional extension in the plane of the substrate. The electrical contacts may have a particularly long shape. In particular, the electrical contact may extend across the connection line, in particular perpendicular to the connection line. For example, the two electrical contacts may be arranged parallel to each other. The balancing resistor may at least partially cover the electrical contacts. The electrical contacts can be formed particularly as conductor tracks.

In the context of the present invention, the expression "connection line " refers in principle to an imaginary line in the plane of the substrate connecting at least two electrical contacts to one another. The at least two electrical contacts may preferably be disposed at a distance in parallel with each other. For example, the connection line may extend between two points of the electrical contact having a minimum distance between the two electrical contacts or through the two points. For example, if the distance or minimum distance between two electrical contacts is d, P1 is a point on the first one of the electrical contacts, P2 is one point on the second one of the electrical contacts, If the distance is d, the connection line may extend through P1 and P2, for example.

The expression "extending direction" in the context of the present invention refers in principle to a virtual line extending across the connecting line, in particular perpendicular to the connecting line and characterizing the main extending direction of the balancing resistance. For example, the line may be a long symmetry axis of the balancing resistance or a line forming the longitudinal axis of the balancing resistance.

The device may further comprise at least one sensor element. The expression "sensor element" means, in principle, any element designed to detect at least one characteristic of the medium. The sensor element may be, for example, a ceramic sensor element. In particular, the sensor element may comprise at least one solid electrolyte sensor element. In the context of the present invention, "solid electrolyte" refers in principle to a solid having electrolyte properties, i. E. Ionic conductivity, for example oxygen ion conductivity. In particular, it may be a ceramic solid electrolyte. For example, the solid electrolyte can comprise zirconium dioxide, such as yttrium or scandium stabilized zirconium dioxide. Other embodiments are possible.

The solid electrolyte sensor element may comprise at least one sensor cell. The sensor cell may include at least one first electrode, at least one second electrode, and at least one solid electrolyte connecting the first electrode and the second electrode. The first and / or second electrode may be made of a porous, electrically conductive material. The porous, electrically conductive material may comprise at least one ceramic metal compound, in particular a ceramic material, especially a composite material consisting of aluminum oxide or zirconium oxide and a metal matrix, in particular platinum or palladium.

The expressions "first" and "second" electrodes do not denote an order or a rank and the possibility of, for example, the possibility of providing several types of first electrodes and different types of second electrodes, Should be regarded as a pure name. Further, additional electrodes, for example one or more third electrodes, may be present in the sensor cell.

The sensor element may be electrically connected to at least one electrical contact. The sensor element may be, for example, a lambda probe or a NOx sensor. The balancing resistance may be arranged in particular on at least one signal line or supply line of the sensor element, for example a lambda probe or NOx sensor, and / or may be electrically connected to at least one signal line or supply line.

Basically, the ohmic resistance per unit area can increase with decreasing thickness of the balancing resistance. The thickness of the balancing resistor may therefore be alternatively or additionally selected as small as possible. For example, the thickness of the balancing resistance may be in the range of 5 탆 to 50 탆, preferably in the range of 7 탆 to 20 탆, particularly preferably in the range of 10 탆 to 13 탆. In principle, other dimensions are possible. The resistance value of the balancing resistance, especially the terminal resistance value, may increase. The ohmic resistance per unit area of the balancing resistance is in principle a function of the balancing resistance deflection and / or the selection of one or more conductive pastes and / or the parameters of the sintering process and / or the additional dimensions of the balancing resistance, in particular the balancing resistance length and / And / or the width B2 of the balancing resistance.

The device may also include at least a cut through the balancing resistance, perpendicular to the connecting line, particularly across the connecting line. This cut may be present with the device fully adjusted and may be formed during the adjustment process described below. The expression "cut " in connection with the present invention in principle indicates the separation and / or division of the balancing resistance. The cut may have an L-shape in particular. In principle, however, other shapes are possible. The L-shape may include long legs and short legs. The long legs may extend parallel to the connection line. The balancing resistor may include a short leg and a remaining face extending between the lateral sides of the balancing resistor. The cut can fully penetrate the balancing resistance to the substrate. The cut can be designed to set the ohmic resistance of the balancing resistor. In principle, a higher termination resistance value can be achieved by using a larger amount of resistive paste.

In addition, a method of adjusting the signal of the apparatus is proposed. The method may include the steps described below. The steps may be performed in a predetermined order, for example. However, other sequences are possible. Also, one or more steps may be performed simultaneously or over time. Also, one, some or all of the steps may be performed once or repeatedly. The method may further comprise additional steps.

The method of adjusting the signal of the device according to the invention, as in one of the embodiments described above or below, comprises the following steps:

a) providing an apparatus according to the invention, for example in one or more of the embodiments described above or below;

b) detecting an ohmic resistance between the electrical contacts;

c) performing at least one cut through a balancing resistor.

The length and / or geometry of the cut is selected such that the ohmic resistance has a predetermined set value. Thus, for example, at least one measurement variable that depends on the ohmic resistance of the balancing resistor can be detected, and the balancing resistance is varied by the cut until the measurement variable corresponds to a setting for the measurement variable, e.g., So that the ohmic resistance corresponds to the set value for the ohmic resistance. For example, if the device comprises a sensor element as described above, the sensor element can be operated, for example, under precisely defined conditions, and at least one measurement value of the sensor element is detected as a measurement variable, Can be compared. However, other adjustments are possible.

The cut may comprise a straight line extending across the connecting line, in particular perpendicular to the connecting line. First, a blind cut having a predetermined length may be performed. The expression "blind cut" in the context of the present invention refers in principle to an initial cut, which is generally carried out in a partial step and whose length is smaller than the cut at the end of the process . The initial cut may form part of the entire cut at the end of the process.

Subsequently, steps b) and c) can be repeatedly performed until the ohmic resistance has a set value.

Step c) can be carried out in particular using laser technology. In particular, step c) may comprise, at least in part, a gradual clock equation setting of the laser points. Additional cuts may be performed parallel to the connection line after the ohmic resistance has reached the set point.

The proposed apparatus and method have many advantages over known apparatuses and methods. In principle, process reliability and adjustment accuracy can be increased in the relevant adjustment range and at high balancing resistances. By virtue of the shape of the balancing resistance, many advantages can be achieved, particularly with respect to process reliability. The resistance curves for the tuning range, especially 55 Ω to 250 Ω, can be much more flat. As a result, in the method of adjusting the signal of the apparatus, the set value of the resistance range can be more accurately achieved as intended, and the surface of the balancing resistance can be used optimally.

By virtue of the shape of the balancing resistors, higher termination resistances, in particular up to 1400 ohms, can be achieved in principle when using the same material and in smaller areas. In particular, a larger residual web width can be achieved.

Various effects can be achieved by the shape of the balancing resistor. The shape of the balancing resistor may correspond substantially to a series of individual electrical resistances. In particular, the total electrical resistance of the individual resistors due to the shape of the bones becomes higher, especially in the transition region. By increasing the total resistance, the distance between the maximum possible total resistance and the set point can be increased and the residual web width can be increased.

The manufacturing method of the device may comprise the following steps: electrical contacts, in particular conductor tracks, can be printed on the substrate. Then, a balancing resistor can be printed. Additional sub-steps of the method may include printing a protective layer or providing a solder paste. The balancing resistors and additional elements can be printed according to the geometry of the conductor tracks.

Higher set values can be achieved by the shape of the balancing resistor, especially the bone shape as described above. Alternatively or additionally, the thickness of the balancing resistor may vary. As the thickness decreases, the ohmic resistance per unit area may increase. Alternatively or additionally, a number of different resistance pastes may be provided. Resistive pastes may have different resistance values.

Additional optional details and features of the present invention are set forth in the following description of a preferred embodiment schematically depicted in the drawings.

Figures 1a, 1b and 1c are plan views of an embodiment of the device according to the invention.
2 is a graph showing the resistance curve of an embodiment of the apparatus according to the invention for cut length;

Figures 1A, 1B and 1C illustrate an exemplary embodiment of an apparatus 110 according to the present invention for detecting at least one characteristic of a medium. Apparatus 110 is shown in plan view in Figures 1A-1C.

Apparatus 110 includes at least one substrate 112, at least two electrical contacts 114, and at least one balancing resistor 116. The electrical contact 114, preferably provided with exactly two contacts, is preferably provided on the substrate 112. The balancing resistor 16 is also preferably provided in the substrate, and the electrical contact 114 and the balancing resistor 116 may be partially overlapping.

The substrate 112 may have, for example, a box-like or plate-like basic shape. A film shape is also possible. The substrate 112 may be made, for example, completely or partially from a ceramic material. For example, the substrate may comprise aluminum oxide. Other materials such as glass fiber reinforced plastic materials and / or polyimide, for example, are also possible in principle.

The balancing resistor 116 electrically connects the electrical contacts 120 along the connecting line 118 so that current can flow between the electrical contacts 114 in parallel to the connecting line 118. The balancing resistor 116 extends in the extending direction 120 perpendicular to the connecting line 118, particularly across the connecting line 118. The balancing resistor 116 has a width B that varies along the direction of extension 120.

The balancing resistor 116 includes at least one cross-sectional constriction 122 along the extension direction 120. The width B may be narrower in at least one region 124 outside the cross-sectional constriction at the cross-sectional constriction 122. [ The balancing resistor 116 may include a boundary 128 in at least one transition 126 to the cross-sectional constriction. For example, the boundary 128 may extend diagonally relative to the connecting line 118. The balancing resistor 16 may have a width B1 in at least one first region 130 and a width B2 in at least one second region 132. [ The balancing resistor 116 may have a bony or dumbbell shape in particular.

The balancing resistor 116 may include at least one exposed surface 134. The exposed surface 134 may be accessible to the laser beam. The device 110 may include at least one cut 136 through a balancing resistor 116. In particular, the cut may traverse the connecting line 118, in particular perpendicular to the connecting line 118. The cut 136 may have an L-shape in particular. The L-shape may include long legs 138 and short legs 140. The long leg 138 may extend parallel to the connection line 118. The balancing resistor 116 may include a remaining surface 142 that extends between the short leg 140 and the transverse side 144 of the balancing resistor 116. The cut 136 may be designed to set the ohmic resistance of the balancing resistor 116. The cuts 136 may completely penetrate the balancing resistors 16 to the substrate 12.

The electrical contacts 114 may be made of an electrically conductive material such as, for example, platinum or silver palladium. Electrical contacts 114 may extend on the surface 145 of the substrate. The electrical contacts 114 may extend perpendicularly to the connecting line 118, particularly to the connecting line 118. The electrical contacts 114 may be disposed parallel to each other. The balancing resistor 116 may at least partially cover the electrical contacts 114. Electrical contacts 114 may be connected to the sensor element.

1B and 1C illustrate other embodiments of an apparatus 110 according to the present invention. Since much of the embodiments correspond to the device 110 shown in FIG. 1A, the above description can be referred to. The apparatus 110 of FIG. 1B includes a balancing resistor 116 with a boundary 128 extending in a curve. The device 110 of Figure 1C includes a balancing resistor 116 across which the boundaries extend.

Figure 2 shows resistance curves 152,154 and 156 of the device including the resistance curves 146,141 and 150 of the exemplary embodiment of the device 110 according to the present invention and a balancing resistor having a rectangular basic shape do. The electrical resistance W in ohms is shown for the cut length L in millimeters. The adjustment can be made in the resistance range (A), for example, in the range of 55 내지 to 250.. The resistance curves 146 to 156 may rise flat in the resistance range A. [ The resistive curves 146, 148 and 150 of the devices 110 according to the present invention may rise more flatly in the resistance range A than in a device comprising a rectangular balancing resistance. The tangent line T1 or T2 is placed at the upper limit A1 of the resistance range in the resistance curves 146 to 156 and the angle W1 between the tangent line T1 or T2 and the upper limit A1 of the resistance range A Or W2) can be detected. The angle W2 of the resistance curves 146, 148 and 150 of the embodiment of the device 110 according to the invention is less than the angle W1 of the resistance curves 152, 154 and 156 of the device comprising the rectangular balancing resistance Can be small. As a result, especially higher process reliability can be achieved.

The resistive curves 146, 148 and 150 of the embodiment of the device 110 according to the present invention also have a greater termination resistance than the resistance curves 152, 154 and 156 of the embodiment of the device comprising a rectangular balancing resistance, It has a termination resistance up to 1400 Ω.

110 device
112 substrate
114 Electrical contacts
116 Balancing resistance
118 Connector
120 Extension Direction
122 Sectional Shrinkage
134 exposed surface
136 cuts

Claims (10)

An apparatus (110) for detecting at least one characteristic of a medium, the apparatus (110) comprising:
At least one substrate (112);
At least two electrical contacts 114; And
- at least one balancing resistor (116)
The balancing resistor 116 electrically couples the two electrical contacts 114 along the connecting line 118 to allow current to flow between the electrical contacts 114 parallel to the connecting line 118 , Said balancing resistor (116) extending across the connection line (118) in a direction of extension (120) and having a width (B), said width (B) A device for detecting a characteristic. The apparatus of claim 1, wherein the balancing resistor (116) includes at least one cross-sectional shrinkage portion (122) along the extension direction (120) Is smaller than at least one region other than the portion (122). The apparatus of any preceding claim, wherein the balancing resistor (116) has a shape selected from the group consisting of a bone shape, a dumbbell shape, and a columnar shape with a widened end. A method as claimed in any one of the preceding claims, wherein the balancing resistor (116) comprises at least one exposed surface (134), the exposed surface (134) A device for detecting a characteristic. 5. Device according to any one of claims 1 to 4, wherein the device (110) further comprises at least one sensor element, the sensor element being electrically connected to at least one of the electrical contacts (114) And detect at least one characteristic of the medium. 6. Device according to any one of claims 1 to 5, wherein the device (110) comprises at least one cut (136) through the balancing resistor (116) across the connecting line (118) A device for detecting a characteristic. 7. The apparatus of claim 6, wherein the cut (136) is L-shaped. A method of adjusting a signal of an apparatus (110) for detecting at least one characteristic of a medium,
A method comprising: a) providing an apparatus (110) according to any one of claims 1 to 7;
b) detecting an ohmic resistance between the electrical contacts 114;
c) implementing at least one cut (136) through the balancing resistor (116)
The length and / or geometry of the cut (136) is selected such that the ohmic resistance has a predetermined set value. 9. The method of claim 8, wherein the steps b) and c) are repeatedly performed until the ohmic resistance has the predetermined set value. 10. The method of claim 9, wherein additional cuts are performed parallel to the connection line (118) after the ohmic resistance reaches the set point.

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