ANISOTROPE CONDUCTIVE ADHESIVES FOR AN RTD

Description

[0001] The invention relates to a sensor element comprising a sensor chip and an anisotropically conductive material, wherein the anisotropically conductive material covers a trimming structure of the sensor chip, as well as to a sensor module containing the sensor element and a method for producing the sensor module.

[0002] Resistance sensors, e.g. made of platinum, have long been known in the state of the art. Such resistance sensors have a temperature-sensitive resistance structure arranged on an electrically insulating carrier. The resistance structure is contacted via contact pads. The sensors are usually sold with a precisely defined nominal resistance and temperature coefficient. However, sensors with such defined nominal resistances are difficult to manufacture directly. Since the resistance structure is influenced by the manufacturing process, the resistances of the raw sensors exhibit a certain degree of fluctuation. In order to adjust the sensors to the nominal resistance as precisely as possible, the sensors are usually manufactured with a resistance slightly lower than the nominal resistance and then adjusted to the nominal resistance by increasing the resistance.Adjusting the resistance of the resistor structure to a nominal resistance is also called trimming. For this purpose, the resistance of the sensor structure can be subsequently changed in a specially provided trimming area by extending the length of the conductor track or separating parallel resistors. This increases the resistance. In the prior art, the trimming process is often achieved by removing part of the conductor structure in the trimming areas using laser radiation. To protect the conductor track in the trimming area from environmental influences, the trimming area must be sealed after trimming. This is usually done by subsequently sealing the trimming area with an electrically isotropically insulating cover layer made of glass, ceramic, glass-ceramic, or a polymer.The disadvantage is that, especially during the application and firing of glasses, ceramics, or glass-ceramics, the resistance of the already trimmed resistor structure can be changed again. EP 3 789 745 A1 is an example of a resistance sensor according to the prior art.

[0003] It would be desirable if the application of such a cover layer after trimming could be dispensed with before the sensor is installed in its final application.

[0004] Furthermore, there is a trend towards miniaturization in sensors, especially resistance sensors. Such miniaturized sensors can be mounted with very little space, for example, on circuit boards in the semiconductor industry. This is where conventional assembly and connection techniques reach their limits. Resistance sensors, especially in the form of surface-mounted devices (SMD), are usually mounted by soldering onto the conductor tracks of a substrate, such as a printed circuit board. (printed circuit board, PCB). However, with very small sensors, over-soldering can occur, resulting in short circuits between contacts. It is desirable if resistance sensors, especially miniaturized resistance sensors, can be mounted on substrates in such a way that the risk of short circuits is reduced.

[0005] It was an object of the invention to provide a sensor element in which a dedicated sealing of the trimming structure, e.g., with a glass layer or a ceramic layer, can be dispensed with. In particular, it was an object of the invention to provide a sensor element in which the sealing of the trimming structure, or a trimming point, does not have to be implemented prior to the installation of a sensor chip in a sensor module.

[0006] A further preferred object was to provide a sensor element that can be easily mounted on a substrate with closely spaced conductor structures.

[0007] A further object of the invention was to provide a simplified method for manufacturing a sensor module, in particular for a sensor module containing a miniaturized sensor chip that is contacted with closely spaced conductor structures. In particular, the risk of short circuits should be reduced.

[0008] At least one object is achieved by the subject matter of the independent claims. The subject matter of the dependent claims represent preferred embodiments of the invention.

[0009] According to the invention, the invention relates to a sensor element comprising a sensor chip and an anisotropically conductive material, wherein the sensor chip comprises a) an electrically insulating carrier having a first side and a second side opposite the first side, b) at least two contact pads arranged on the first side of the electrically insulating carrier and c) a resistance structure on the first side of the electrically insulating carrier, which extends from a first contact pad to at least one further contact pad, wherein the resistance structure contains at least one trimming structure, characterized in that an anisotropically conductive material is arranged on the first side of the electrically insulating carrier, at least on the at least one trimming structure. The anisotropically conductive material can be arranged indirectly or directly on the at least one trimming structure.

[0010] The sensor element comprises a sensor chip and an anisotropically conductive material. The anisotropically conductive material is therefore preferably not part of the sensor chip. The sensor chip can be a resistance sensor, in particular a resistance temperature sensor (RTD), with a metallic resistance structure. The resistance sensor can be, for example, a PTC thermistor. The metallic resistance structure can, for example, comprise or consist of platinum, palladium, nickel, aluminum, or another metal. Optionally, the metallic resistance structure can comprise or consist of an alloy. In one possible embodiment, the alloy can be an aluminum alloy, e.g., an alloy containing 0.5–2 wt.% copper.

[0011] In a preferred embodiment, the sensor chip is a temperature sensor chip. In another possible embodiment, the sensor chip is a strain gauge or a pressure sensor. In an alternative embodiment, it can be a resistance heater, particularly with a meander structure, with a precisely adjusted resistance.

[0012] In a further preferred application, the sensor element is a complex system comprising a plurality of electronic components arranged on an electrically insulating carrier, comprising a resistance structure with at least one trimming structure, wherein an anisotropically conductive material covers the at least one trimming structure, preferably comprising a trimming point.

[0013] Particularly preferably, the resistance structure contains at least one trimming structure. This trimming structure has preferably been modified, ie, trimmed, by ablation, e.g., by means of laser radiation. The regions of the at least one trimming structure that have been modified are also called trimming points.

[0014] In a particularly preferred embodiment, the sensor chip can be a sensor as described in WO2021047948A1, in particular in the form of a temperature sensor. Most preferably, the sensor chip is a sensor chip as described in the Figures 1 and 2 WO2021047948A1 with the associated description.

[0015] An anisotropically conductive material preferably comprises an electrically insulating matrix in which electrically conductive particles are dispersed. In the context of the invention, conductive particles also include conductive elements, e.g., cylinders, that are firmly embedded in an electrically insulating matrix and extend in a preferred direction through the anisotropically conductive material. The electrically insulating matrix preferably comprises or consists of an organic material.

[0016] The electrically insulating matrix of the anisotropically conductive material can preferably be selected from organic polymers, such as epoxies, and silicones. Most preferably, the electrically insulating matrix of the anisotropically conductive material contains or consists of an epoxy. Those skilled in the art of assembly and connection technology are generally familiar with anisotropically conductive materials, in particular anisotropically conductive adhesives, and these are commercially available. They are able to select and apply suitable materials.

[0017] Anisotropically conductive materials can be understood to mean, in particular, anisotropically conductive adhesives, anisotropically conductive films, or tapes. Anisotropically conductive adhesives and anisotropically conductive films preferably contain polymers or polymer precursors filled with conductive particles. Particularly preferred polymers are thermosetting polymers, which can be obtained by crosslinking a polymer precursor or a polymer system. Polymer precursors can be, among other things, monomers or oligomers. Within the scope of the invention, an anisotropically conductive material can be understood to mean both a polymer precursor and a cured or crosslinked polymer material, e.g., an adhesive.

[0018] The anisotropically conductive material can be selected from the group consisting of anisotropically conductive two-component adhesives, anisotropically conductive one-component adhesives, anisotropically conductive hot melt adhesives, and anisotropically conductive films. Anisotropically conductive films can be, for example, adhesive tapes filled with conductive particles, e.g., metal particles, in particular silver particles. The anisotropically conductive material advantageously contains deformable or non-deformable electrically conductive particles. Examples of deformable particles are carbon particles, in particular graphite particles. The degree of filling of the anisotropically conductive material with conductive particles is preferably selected such that the conductive particles do not form electrical contacts (i.e., percolation paths) unless subjected to external mechanical action.In some embodiments of the invention, an adhesive tape can also be used as an anisotropically conductive material, comprising conductive and insulating regions perpendicular to the tape surface. Such adhesive tapes are also called zebra rubber or conductive rubber. Within the scope of the invention, anisotropic conductivity refers in particular to anisotropic electrical conductivity, although thermal conductivity may also be included.

[0019] The sensor chip has an electrically insulating carrier, at least two contact pads and a resistance structure.

[0020] The electrically insulating carrier has a first side and a second side opposite the first side. Preferably, the first side and the opposite second side of the electrically insulating carrier are synonymous with the first and second sides of the sensor chip. Preferably, the first side of the electrically insulating carrier has an area that is at most 1 mm 2 , in particular, the first side of the electrically insulating carrier has an area that is at most 0.3 mm 2 and very particularly preferably at most 0.2 mm 2 . Thus, the first side of the sensor chip, which is predetermined by the first side of the electrically insulating carrier, usually also has the specified areas. The electrically insulating carrier has a dielectric material on at least one of the sides, in particular on the first side on which the contact pads and the resistance structure are arranged.Optionally, both sides of the electrically insulating carrier have a dielectric material. The dielectric material is preferably configured as a continuous layer. The dielectric material can optionally be arranged on an electrically conductive material or on a dielectric material. The electrically conductive material can be, for example, a metal or a doped semiconductor. If the dielectric material of the electrically insulating carrier is arranged on an electrically conductive material, the electrically insulating carrier can also be referred to as a multi-layer structure. The electrically conductive material of the electrically insulating carrier is preferably not in contact with the contact pads or the resistor structure. In one possible embodiment, the electrically insulating carrier consists of dielectric material.

[0021] In one possible embodiment of the invention, the electrically insulating carrier consists of one or more dielectric materials. The dielectric material of the entire electrically insulating carrier or parts thereof can, for example, be selected from the group containing glasses, ceramics, glass ceramics, and polymers. The glasses can be selected from silicate glasses. The ceramics can, for example, be selected from oxide ceramics, nitride ceramics, or carbide ceramics. Oxide ceramics can, for example, include silicon oxide, aluminum oxide, titanium oxide, and zirconium oxide, as well as mixtures of these oxides. The nitride ceramic can comprise a metal nitride and is preferably selected from the group containing titanium nitride, silicon nitride, and aluminum nitride. The polymers can, for example, comprise polyimides or silicones.

[0022] In an advantageous embodiment of the invention, the electrically insulating carrier comprises or consists of an inorganic material. The inorganic material preferably comprises silicon and a compound of silicon. In a particularly preferred embodiment of the invention, the electrically insulating carrier can comprise a silicon wafer which is provided with a layer of a dielectric material at least on the first side. The silicon wafer can be either doped or undoped. Preferably, the dielectric layer on the silicon wafer contains or consists of a metal oxide, e.g., silicon oxide or aluminum oxide. The advantage of using a silicon wafer is that it has a particularly low surface roughness, which is particularly advantageous for very small sensors with thin resistance layers. In the event that the electrically insulating carrier contains a conductive material, e.g.,a metal sheet or a doped semiconductor wafer, it is preferably necessary to ensure that a dielectric material is present at least on the first side, in particular in the form of a continuous layer, so that the conductive structures applied on the first side, such as the resistance structure or contact pads, are not short-circuited.

[0023] The electrically insulating carrier is preferably designed as a thin plate or disc, e.g., a rectangular plate. Optionally, the sensor chip, and thus also the electrically insulating carrier, can be flexible. In a preferred embodiment, the sensor chip has a flexibility that allows it to be bent with a bending radius of curvature of at least 5 mm, preferably at least 2 mm, preferably at least 1 mm, wherein a relative difference in the specific resistance (dR / R(0)), where d denotes delta or Δ, of the resistance structure before and after bending must preferably not exceed 2%, in particular 1%, and most preferably 0.5%.

[0024] Such flexibility of the sensor chip can be measured as follows. The sensor chip is bonded to a polyimide film (Kapton® < 25 µm) to determine the flexibility of the sensor chip. Before bonding, the surface of the Kapton film is activated by treatment with a corona discharge. A cyano-based adhesive (MINEA, superglue) is applied to the back of the sensor chip, and the sensor chip is pressed onto the polyimide film for the adhesive's reaction time. The polyimide film is then wrapped around a cylindrical rod with the sensor chip facing outwards. The diameter of the rod is selected in the range of 0.25 mm to 10 mm. During wrapping, the polyimide film is in close contact with the surface of the cylindrical rod. Therefore, the radius of curvature of the sensor chip is approximately half the rod diameter. The duration of the maximum bending is set to about one second.The winding or bending process preferably consists of a bending and a unbending process. The relative difference in the resistivity d R / R(0) (where d denotes delta or Δ) of the electrical structure is measured before and after each bending cycle. The sensor chip can be considered flexible as long as the radius of curvature is not smaller than the minimum radius Rm. Rm is defined as the radius at which d R / R(0) has a value of 2%, in particular 1%, and most preferably 0.5%.

[0025] Furthermore, the sensor chip has at least two contact pads arranged on a first side of the electrically insulating carrier. Contact pads can be understood as locally applied electrically conductive layers which can be electrically and mechanically robustly contacted, for example, with electrical lines or wires. Contacting can possibly be achieved by wire welding or wire bonding. Each of the at least two contact pads can preferably take up to 25% or particularly preferably up to 10% of the area of ​​the first side of the electrically insulating carrier. The contact pads can, for example, be arranged at opposite ends of the first side of the electrically insulating carrier or at the same end. The further the contact pads are apart from each other, the lower the risk of short-circuiting them during contacting. Larger contact pads have the advantage that they are easier to contact.The thickness of the contact pads on the electrically insulating carrier is preferably at least 100 nm, in particular at least 200 nm and very particularly preferably at least 500 nm. Furthermore, the thickness of the contact pads can be at most 5 µm, in particular at most 2 µm and very particularly preferably at most 1 µm.

[0026] The contact pads can often be wider than the conductor structure of the resistor structure to enable better contact with wires or cables. If the contact pads are not wider than the resistor structure, the ends of the resistor structure can also be considered contact pads.

[0027] In one possible design, the contact pads are provided with feedthroughs. vias) contacted so that wires or cables can be attached to the second side of the electrically insulating carrier.

[0028] Preferably, at least one contact pad can have at least one contact patch. Contact patches are particularly preferably in direct electrical contact with the contact pad on which they are arranged. Contact patches are preferably raised, spatially limited metal layers (also called spots or patches). Patches The contact patches can be designed for improved electrical and mechanical contacting of the contact pad and can be arranged on the contact pads. A contact patch preferably occupies less than 10% of the area of ​​the first side of the electrically insulating carrier. A contact patch preferably occupies less than 40% of the area of ​​the first side of the contact pad, even more preferably less than 25%. To determine the area of ​​the contact patches, the projection of the contact patch onto the contact pad in a plan view perpendicular to the first side of the electrically insulating carrier is preferably used.

[0029] Particularly preferably, two to sixteen contact patches can be arranged on a contact pad, in particular two to eight contact patches. Contact patches can be produced, inter alia, by galvanic processes such as, for example, electrochemical (ECD) and electroless (ELD) deposition of metals on contact pads. Contact patches can optionally also be produced using a different process, e.g., thick-film processes comprising printing. The contact patches preferably comprise a different metal or alloy than an underlying contact pad. If there is a layer on the contact pads that hinders metal deposition, in particular an insulating layer, the layer can be removed selectively before metal deposition, for example with a laser, and contact patches can then be applied to the exposed areas using the above-mentioned processes, in particular the galvanic processes.The contact patches can preferably contain or consist of a metal selected from the group consisting of nickel, gold, and silver, or another electrically conductive material. Electroplated layer systems are also possible. Other possible methods for applying contact patches include screen printing or pad printing. The thickness of a contact patch is preferably at least 2 µm, in particular at least 5 µm, and very particularly preferably at least 10 µm. In addition, the thickness of a contact patch is preferably at most 30 µm, in particular 20 µm, and in particular at most 15 µm. Contact patches with thicknesses in this thickness range can preferably be used to exert pressure effectively on anisotropically conductive materials, and they can be contacted effectively. The contact patches preferably protrude 5 µm to 20 µm, in particular 5 to 10 µm, beyond the resistor structure or the optionally present insulating layer of the sensor chip.This allows the contact patches to exert sufficient local pressure on the anisotropically conductive material, preferably during the manufacture of a sensor module, to establish an electrical connection without creating short circuits outside the contact patches.

[0030] A contact patch advantageously has an area of ​​0.1 mm 2 or less, in particular 0.01 mm 2 or less, and particularly preferably 0.005 mm 2 or less. The cross-section of a contact patch in a plane parallel to the electrically insulating carrier can preferably be in the range from 10 µm to 100 µm. Furthermore, the edge-to-edge distance between two adjacent patches on a contact pad can be in the range from 1 µm to 300 µm. In a preferred embodiment, the maximum cross-section of a contact patch in a plane parallel to the electrically insulating carrier is larger than the underlying contacted area of ​​the contact pad. The contact patches preferably protrude beyond the optionally present insulating layer, or in other words, the contact patches can thus have a mushroom shape. Alternatively, the contact patches can have a constant diameter or do not widen towards the top.

[0031] According to the invention, a resistance structure is arranged on the first side of the electrically insulating carrier, which extends from a first contact pad to at least one further contact pad. In the context of the invention, a resistance structure can be understood as a conductor, in particular a metallic conductor, which has a characteristic change in resistance as a function of temperature. In a preferred embodiment, the resistance structure comprises or consists of a metal. The metal can preferably be selected from the group comprising platinum, nickel, aluminum, palladium, gold, silver and copper, as well as alloys which contain at least one of these metals as a main component. The main component of an alloy can be understood as the element which has the highest weight fraction.More preferably, the alloy may contain rhodium, copper, platinum, nickel, aluminum, palladium, gold, silver and copper as at least one of the further alloying elements.

[0032] The resistor structure contains at least one trimming structure. Furthermore, the resistor structure can be structured and, for example, have a meandering structure. In a preferred embodiment of the invention, the resistor structure and the at least two contact pads are manufactured from a single piece.

[0033] The thickness of the resistance structure on the electrically insulating carrier is preferably at least 100 nm, in particular at least 200 nm and very particularly preferably at least 500 nm. Furthermore, the thickness of the resistance structure can be at most 5 µm, in particular at most 2 µm and very particularly preferably at most 1 µm.

[0034] For example, the contact pads and the resistor structure can be obtained individually or jointly from a flat conductive layer, in particular a metallic layer, by subsequent structuring. The layer can be produced using thin-film or thick-film processes. Optionally, the resistor structure and the contact pads contain the same material or consist of the same material.

[0035] In an alternative embodiment, the contact pads and the resistor structure can be applied independently of each other. In this case, the contact pads and the resistor structure can be manufactured using the same or different methods mentioned herein. The layer thickness of the resistor structure and the contact pads can optionally be the same or different and can each optionally have the values ​​specified for the resistor structure.

[0036] The resistor structure comprises at least one trimming structure. Optionally, the resistor structure comprises two or more trimming structures. A trimming structure is preferably a conductive structure whose resistance can be changed, in particular increased, by material manipulation. In particular, the at least one trimming structure can be manipulated such that the resistance of the entire resistor structure containing the trimming structure corresponds to a specified nominal resistance. In particular, the material manipulation can be ablation. The ablation can preferably be carried out using a method selected from etching, milling, grinding and laser ablation. Whenever a nominal resistance is mentioned within the scope of the invention, it is obvious to a person skilled in the art that this is a nominal value and that the actual resistance can fluctuate within a tolerance range around the nominal resistance, e.g. due to production fluctuations.For example, for platinum resistor structures, the tolerance ranges can be specified in a standard, e.g., a DIN standard. The at least one trimming structure forms, in particular, an electrical series or parallel circuit with the remaining portion of the resistor structure.

[0037] The at least one trimming structure can be designed such that its resistance can be changed in steps or continuously. A step-by-step trim can also be referred to as a digital trim, and a continuous trim as an analog trim. A structure that allows a step-by-step adjustment of the resistance is, for example, a conductor track structure divided into parallel individual strands, which can be processed such that individual ones of the parallel conductor tracks can be separated, thereby reducing the conductor cross-section. A structure that allows a continuous adjustment of the resistance can, for example, be a strip, which can be processed such that the distance through which the electrical current must flow is continuously lengthened or such that the conductor cross-section is reduced, e.g. by cutting a slit into the strip.Preferably, the resistance structure comprises at least one trimming structure for an analog trim and at least one trimming structure for a digital trim, since this arrangement allows the resistance to be adjusted particularly precisely. Most preferably, both trimming structures have trimming points.

[0038] In one embodiment of the invention, the sensor element has an insulating layer, wherein the insulating layer is preferably arranged on the first side of the electrically insulating carrier. The resistance structure is preferably partially or completely covered with the insulating layer, at least in the region outside the at least one trimming structure. In a preferred embodiment, the at least one trimming structure is at least partially not covered by an insulating layer. The contact pads can optionally also not be covered by the insulating layer. This allows the material of the trimming structure to be manipulated, in particular by means of laser ablation. For example, the insulating layer can have a recess in the region of a trimming structure. The recess, also called an opening or window, can be created directly during the production of the insulating layer, or the insulating layer is first produced flat and the recess is subsequently created in the insulating layer.

[0039] The insulating layer may comprise or consist of a dielectric material selected from the group consisting of polymers, hybrid polymers, glasses, ceramics, and glass-ceramics. The polymers of the insulating layer preferably comprise at least one material selected from polyimides, parylenes, and epoxies.

[0040] The insulating layer on the first side of the electrically insulating carrier, in particular containing or consisting of polyimide, preferably has an average thickness in the range of 0.5 µm - 50 µm. The thickness is preferably between 2 µm and 20 µm. The thickness of the insulating layer is most preferably in the range of 2.5 µm - 5 µm.

[0041] In one possible embodiment of the invention, the surface of the resistor structure of the sensor chip can be at least partially or even completely coated with a first inorganic passivation layer. The inorganic passivation layer is preferably not the same as the insulating layer. The inorganic passivation layer preferably serves to protect the resistor structure from corrosion and contamination.

[0042] Preferably, both the electrically insulating carrier and the resistance structure are covered with a first inorganic passivation layer. In one possible embodiment of the invention, the first inorganic passivation layer has holes or defects in the region of the at least one trimming structure, which may result from trimming, in particular in the region of the trimming points. Optionally, the material of the first inorganic passivation layer that was removed in the region of the holes or defects can be deposited around these holes or defects and act there as a passivation layer. As a result, parts of a trimming structure that were initially exposed by the trimming process can advantageously be re-passivated in the same process step.

[0043] The first inorganic passivation layer preferably comprises an oxide, a nitride, or an oxide-nitride composite material. The oxide may be a metal oxide and preferably selected from the group consisting of silicon oxide, aluminum oxide, and titanium oxide. The nitride may be a metal nitride and preferably selected from the group consisting of titanium nitride, silicon nitride, and aluminum nitride.

[0044] The oxide-nitride composite material may comprise a multilayer material, for example, a multilayer material comprising at least one oxide layer and at least one nitride layer stacked one above the other. The first inorganic passivation layer preferably has an average thickness in the range of 0.4 µm to 2 µm. If the first inorganic passivation layer comprises an oxide-nitride composite material, in particular a layered material, both the oxide layer and the nitride layer preferably have an average thickness of at least 0.4 µm.

[0045] The inorganic passivation layer is particularly electrically insulating and / or serves as a moisture barrier, e.g. against atmospheric humidity.

[0046] According to the invention, an anisotropically conductive material can be arranged indirectly or directly on the first side of the electrically insulating carrier, at least on the at least one trimming structure. Indirect means that further materials, in particular layers, are present between the at least one trimming structure and the anisotropically conductive material. This further material can in particular be a first inorganic passivation layer. Direct here means that the at least one trimming structure is in contact with the anisotropically conductive material. The anisotropically conductive material is preferably arranged on the at least one trimming structure in such a way that it closes, in particular hermetically seals, the at least one trimming structure. This allows a trimming structure to be well protected from environmental influences. Furthermore, the entire resistor structure and the contact pads are preferably covered with the anisotropically conductive material.The anisotropically conductive material can be present in the form of a layer. If there is an insulating layer on the first side of the carrier, the anisotropically conductive material is arranged on this layer.

[0047] The at least one trimming structure preferably has at least one region in which a portion of the trimming structure is severed and / or in which material is partially removed in a continuous region of the trimming structure. A severed or removed region of a trimming structure is also called a trimming point.

[0048] Optionally, an existing first inorganic passivation layer is removed or modified in the severed or removed regions of the at least one trimming structure. If the insulating layer is present in the region of the at least one trimming structure, it can be at least partially removed by trimming. Particularly preferably, the sensor element is trimmed through an optionally present first inorganic passivation layer.

[0049] In a particularly preferred embodiment of the invention, the at least one trimming structure covered with the anisotropically conductive adhesive is at least partially or completely not covered by at least one further passivation layer or a cover layer on the side facing away from the electrically insulating carrier. In particular, no glass or ceramic layer or no polymer layer is arranged at least on parts of the at least one trimming structure. In a further preferred embodiment, no polymer layer, glass layer, or ceramic layer is present on at least part of the at least one trimming structure, while in another region of the first side, e.g., on another part of the resistor structure, a polymer layer, glass layer, or ceramic layer is located as a cover layer or passivation layer.

[0050] In known, trimmed sensor elements from the prior art, particularly Pt RTDs, trimming is typically performed through a window in one or more passivation layers or capping layers, or prior to the application of a passivation layer or capping layer. This passivation layer in the prior art is usually made of glass or glass-ceramic.

[0051] Preferably, the first side of the electrically insulating carrier, and thus preferably also the first side of the sensor chip, has an area that is at most 1 mm 2 , in particular the first side of the sensor chip has an area that is at most 0.3 mm 2 and very particularly preferably at most 0.2 mm 2 . Furthermore, the sensor chip can have a thickness of at most 200 µm, preferably of at most 100 µm and very particularly preferably of at most 50 µm. The thickness is determined in particular perpendicular to the surface on which the resistance structure is arranged. The sensor chip can be manufactured, for example, using lithographic processes as used in semiconductor production. The advantage of a low thickness of the sensor chip is that particularly flat sensor modules can be realized that require little space.In addition, sensor chips with a small thickness have a low mass, which can improve the response time.

[0052] The sensor chip preferably has a nominal resistance. The nominal resistance at 0°C can be, for example, 50 Ω, 100 Ω, 200 Ω, 250 Ω, 1000 Ω, 2500 Ω, 5000 Ω or 10000 Ω. In the event that the resistance of the resistor structure is less than the nominal resistance after the resistor structure has been created, the resistance can be adjusted to the nominal resistance. Adjusting to a narrow tolerance range close to the nominal resistance, also called trimming, is preferably carried out via the at least one trimming structure. Sensor resistances are preferably adjusted within the tolerance ranges around the nominal resistance according to IEC 751 / EN 60751 or class 1 / 10 B. The trimming of the at least one trimming structure can be carried out by ablation, such as laser ablation. In case the resistance of the resistor structure from the previous manufacturing steps already corresponds to the nominal resistance, trimming can optionally be omitted.

[0053] In one possible embodiment, the sensor chip can be manufactured using a process that includes the following steps: Providing an electrically insulating carrier, applying a conductive layer, in particular a metallic layer, by means of known thin- or thick-film methods, structuring the conductive layer to obtain a resistor structure comprising at least one trimming structure and at least two contact pads between which the resistor structure extends, optionally passivating the resistor structure with an inorganic passivation layer, optionally covering the resistor structure with an insulating layer, wherein the insulating layer at least partially does not cover the at least one trimming structure, and trimming the resistor structure via the at least one trimming structure to a nominal resistance.

[0054] Optionally, contact patches can be applied to the contact pads, e.g. using galvanic processes or by printing.

[0055] The thin-film process used to apply a conductive layer can, in one example, be selected from physical vapor deposition (PVD) and sputtering. The thick-film process can, for example, be a printing process such as a screen printing process.

[0056] The structuring of the conductive layer can be done by lithographic processes or by ablation processes, such as laser ablation.

[0057] A particularly preferred method for producing a sensor chip can comprise the following steps. First, contact pads are arranged on the first side of an electrically insulating carrier. A resistance structure extends from a first contact pad to a further contact pad. The resistance structure contains at least one trimming structure. The resistance structure is preferably meander-shaped, at least in one section. In the next step, an insulating layer is applied to the first side of the electrically insulating carrier, e.g. by spin coating with a polyimide. The insulating layer is then at least partially removed in the region of the contact pads and in the region of the at least one trimming structure. Contact patches are then applied to the contact pad regions freed of the insulating layer. In the following step, the resistance structure is trimmed to a nominal resistance using the at least one trimming structure.The trimming points created in this way are generated, for example, with a laser and can sever individual bridges of a trimming structure. Optionally, parts of the electrically insulating carrier can also be removed in the area of ​​the trimming points, or only parts of the trimming structure. Optionally, the order of the steps for producing the contact patches and trimming can be reversed. The sensor chip obtained by the described steps can be used in a sensor element or sensor module according to the invention.

[0058] In a second aspect, the invention relates to a sensor module comprising a sensor element according to the invention and a substrate having a first surface with conductor structures arranged thereon. The sensor element contains a sensor chip and an anisotropically conductive material. The sensor chip comprises, in particular, an electrically insulating carrier having a first side and a second side opposite the first side, at least two contact pads arranged on a first side of the electrically insulating carrier, and a resistance structure on the first side of the electrically insulating carrier, which extends from a first contact pad to at least one further contact pad, wherein the resistance structure contains at least one trimming structure. An anisotropically conductive material is arranged indirectly or directly on the first side of the electrically insulating carrier, at least on the trimming structure.

[0059] The sensor element on the substrate is arranged with the anisotropically conductive material facing the first surface of the substrate. In other words, the sensor element is aligned with the first side of the electrically insulating carrier facing the first surface of the substrate. Electrically conductive contacts are formed between the contact pads of the sensor chip and the conductor structures of the substrate by the anisotropically conductive material. In particular, the electrical contacts are formed only locally between the contact pads of the sensor chip and the conductor structures of the substrate. The anisotropically conductive material optionally additionally mechanically fastens the sensor chip to the substrate. Furthermore, the anisotropically conductive material preferably ensures a thermal conductivity that is higher than air.At the same time, the anisotropically conductive material preferably electrically insulates the conductor structures on the first surface of the substrate from the resistance structure of the sensor chip outside the contact pads. Depending on the design, the anisotropically conductive material can also electrically insulate other components such as contact patches or the conductor structures on the substrate from each other, preventing them from being in direct electrical contact with each other.

[0060] Preferably, the electrical contacts between the sensor element according to the invention and the conductor structures are formed approximately perpendicular to the substrate plane. Particularly preferably, the angle of the current path to the carrier surface is between 75° and 105°, most preferably between 85° and 95°. Parallel to the carrier, the anisotropically conductive material preferably has an electrically insulating effect.

[0061] The substrate having a first surface with at least two conductor structures arranged thereon is preferably an electrically insulating substrate. The conductor structures can, for example, comprise or consist of a metal. The metal can, for example, be selected from the group comprising gold, silver, and copper. Alternatively, other electrically conductive materials can also be used for the conductor structures. The substrate having a first surface with at least two conductor structures arranged thereon can, for example, be a circuit board, in particular a printed circuit board (PCB). The conductor structures serve, for example, to connect the sensor chip to the periphery. These can be further electrical or electronic components or evaluation electronics.

[0062] The anisotropically conductive material preferably covers the at least one trimming structure at least partially or completely. Particularly advantageously, the anisotropically conductive material can close or even hermetically seal the at least one trimming structure. In particular, the anisotropically conductive material closes trimming points of the at least one trimming structure. This allows the at least one trimming structure to be protected from environmental influences such as oxygen or moisture. The anisotropically conductive material in the sensor module preferably partially or completely fills the space between the sensor chip and the substrate.

[0063] Particularly advantageous is the height h 1 of the contact pads, or the contact pads in combination with the optional contact patches, on the first surface of the sensor chip higher than the height h 2 of the resistance structure. To illustrate the heights h 1 and h 2, Figure 4a). Alternatively, the conductor structures on the substrate that are contacted by the sensor chip are preferably higher than the surrounding area around the conductor structures to be contacted. In this way, the anisotropically conductive material can be compressed in the areas between the contact pads and the conductor structures and can ensure local electrical contact. In this context, reference is made to Figures 4a) and 4b), which illustrate this situation by way of example. The areas of the anisotropically conductive material that are not subjected to increased pressure between the contact pads and the conductor structures during assembly do not contribute to the electrical contact between the sensor chip and the substrate in the finished sensor module.Because the anisotropically conductive material covers and protects the at least one trimming structure, there is no need to additionally apply an insulating layer or covering layer, as is customary in the prior art, in the region of the at least one trimming structure.

[0064] The electrically insulating matrix of the anisotropically conductive material in the sensor module preferably has a higher thermal conductivity than air. Particularly preferred is a thermal conductivity in the direction perpendicular to the substrate, even outside of the mediated electrical contact, of greater than 0.1 W / m K. Preferably, the material combinations and joining processes are selected so that the space between the sensor chip and the substrate is completely filled with anisotropically conductive material. In particular, no gaps form at the interfaces between the anisotropically conductive material and the substrate or the sensor chip. This prevents, among other things, the penetration of water, oxygen, or other contaminants.

[0065] In a preferred embodiment, the sensor element of the sensor module comprises a curing anisotropically conductive material and a flexible sensor chip. The curing of an anisotropically conductive material can lead to shrinkage. The assembly stresses induced by shrinkage can be reduced, among other things, by deforming the flexible sensor chip. In particular, the sensor module comprises a flexible sensor chip connected to a rigid substrate via an anisotropically conductive material. Rigid substrates can be, for example, metal bodies, ceramic, or glass components.

[0066] In another embodiment, a sensor chip can be arranged on a flexible substrate. In this case, the flexible substrate can be deformed to compensate for mechanical stresses caused by shrinkage of a curing anisotropically conductive material. This can reduce the likelihood of mechanical failure.

[0067] In another possible embodiment of the sensor module, a rigid sensor chip can be connected to a rigid substrate via an anisotropically conductive material.

[0068] The average layer thickness of the anisotropically conductive material is preferably less than 20 µm, particularly preferably less than 10 µm. To determine the average layer thickness, only those areas of the anisotropically conductive material that do not provide electrical contact are considered.

[0069] Optionally, at least one contact patch is arranged on each contact pad, as described herein. Furthermore, at least two spatially separated contact patches can preferably be arranged on a contact pad. In one embodiment, the number of contact patches on the contact pads corresponds at least to the number of conductor structures to be contacted on the substrate. The contacting of the conductor structures is preferably achieved via the anisotropically conductive material.

[0070] In a particularly preferred embodiment of the invention, at least two contact patches are arranged on each contact pad, wherein at least two contact patches on the same contact pad are contacted by different conductor structures. In the simplest case, two contact patches are arranged on each contact pad, and each contact patch contacts a respective conductor structure on the substrate. Optionally, more than two contact patches can also be arranged on a contact pad, wherein a first part of the contact patches jointly contact a first conductor structure and another part of the contact patches jointly contact a second conductor structure. In a further alternative, two or more contact patches are arranged on a contact pad, and each contact patch contacts a respective separate conductor structure.

[0071] In embodiments in which at least two contact patches are arranged on a contact pad and each contact patch contacts a separate conductor structure, a four-wire measurement configuration, as is known to those skilled in the art of sensor technology, can preferably be implemented. A four-wire measurement configuration has the advantage that the line and connection resistances cannot distort the resistance measurement.

[0072] In another embodiment of the sensor module, all contact patches on a contact pad can contact the same conductor structure. Alternatively, at least two contact patches on a contact pad can contact different conductor structures on the substrate.

[0073] Furthermore, at least two contact patches can optionally be arranged on a contact pad, wherein at least one of the contact patches has no electrical contact with a conductor structure on the substrate.

[0074] In the event that there are several contact patches on a contact pad, the contact patches are preferably electrically connected to one another only via the contact pad, with no direct electrical conduction from one contact patch to an adjacent contact patch.

[0075] In another possible embodiment for attaching a flexible sensor chip to a non-planar conductor structure, the planar surfaces of the contact patches are no longer arranged plane-parallel, at least after mounting on the conductor structure.

[0076] According to the invention, the invention relates to a method for producing a sensor module, in particular according to the present invention, comprising at least the following steps: a) Providing a substrate having a first surface, wherein a conductor structure is arranged on this first surface, b) Providing a sensor chip according to one of claims 1-11, c) Applying an anisotropically conductive material to the first side of the electrically insulating carrier of the sensor chip or to the first surface of the substrate, d) Positioning the sensor chip on the substrate such that the resistance structure is oriented towards the substrate and the anisotropically conductive material is present between the sensor chip and the substrate, and e) Establishing electrically conductive connections between the contact pads of the sensor chip and the conductor structures of the substrate by means of the anisotropically conductive material.

[0077] Further steps may be performed before, between, and / or after the above steps. Preferably, the order of steps a) to e) is followed.

[0078] In particular, during step e), the sensor chip is additionally mechanically fixed to the substrate by the anisotropically conductive material.

[0079] The substrate having a first surface with conductor structures arranged thereon can be, for example, a circuit board, in particular a printed circuit board ( printed circuit board, PCB). The substrate is preferably an electrically insulating substrate. In step b), a sensor chip is provided, in particular as described herein. The provided sensor chip comprises, in particular, an electrically insulating carrier, at least two contact pads arranged on a first side of the electrically insulating carrier, and a resistance structure on the first side of the electrically insulating carrier, which extends from a first contact pad to at least one further contact pad, wherein the resistance structure contains at least one trimming structure.

[0080] The features of the components of the sensor chip as described herein apply in particular and where applicable also to the sensor chip of the method according to the invention. This preferably also applies conversely to features of the sensor chip described in the context of the method according to the invention.

[0081] The sensor chip in step b) preferably has a nominal resistance. The nominal resistance at 0°C can be, for example, 50 Ω, 100 Ω, 200 Ω, 250 Ω, 1000 Ω, 2500 Ω, 5000 Ω or 10000 Ω. In the event that the resistance of the resistor structure is less than the nominal resistance after the resistor structure has been created, the resistance can be set to the nominal resistance. Adjusting to a narrow tolerance range close to the nominal resistance, also called trimming, is preferably carried out via the at least one trimming structure. Resistances of resistor structures, in particular made of platinum, are preferably set within the tolerance ranges around the nominal resistance according to IEC 751 / EN 60751 or class 1 / 10 B. The trimming of the at least one trimming structure can be carried out by ablation, such as laser ablation.In case the resistance of the resistor structure from the previous manufacturing steps already corresponds to the nominal resistance, trimming can optionally be omitted.

[0082] Preferably, the sensor chip with the resistor structure arranged thereon has a positive resistance temperature coefficient. Particularly preferably, the resistance temperature coefficient is at least 0.003 K -1< in the range from -50°C to 200°C, and most preferably in the range from 0°C to 100°C. Preferably, there is a linear relationship between temperature change and resistance change.

[0083] In step c), an anisotropically conductive material is applied to the first side of the electrically insulating carrier or to the first surface of the substrate. The anisotropically conductive material is preferably applied as a continuous layer or as drops. If the anisotropically conductive material is applied to the first side of the electrically insulating carrier, it is preferably applied such that the contact pads, with contact patches optionally arranged thereon, are covered. In addition, the at least one trimming structure, in particular existing trimming points, is preferably also covered in this step. In another preferred embodiment, the anisotropically conductive material is applied to the first surface of the substrate on which conductor structures, in particular at least two conductor structures, are located. The application of the anisotropically conductive material can preferably be carried out by means of Dispensationor printing. Particularly preferably, the anisotropically conductive material is applied to at least two conductor structures on the substrate, which are to be contacted by the contact pads or the contact patches arranged thereon. The area between two conductor structures may also be covered with anisotropically conductive material. The amount of anisotropically conductive material is preferably selected such that the first side of the electrically insulating carrier is covered with an average layer thickness in the range of 1 µm - 20 µm.

[0084] In step d), the sensor chip is positioned on the substrate so that the resistance structure is oriented towards the substrate and the anisotropically conductive material is located between the sensor chip and the substrate. The positioning can be achieved, for example, with a Pick and place Procedure. Pick and placeUsing this method, sensor chips can be delivered from a tape, such as a heat-release tape, a waffle pack, or a gel pack. Optionally, a robot can be used for positioning. Positioning can be manual, semi-automatic, or automatic. In one embodiment, positioning can be assisted by microscopy.

[0085] In one embodiment, the anisotropically conductive material can at least partially cover the at least one trimming structure and, in particular, completely hermetically seal it. For example, the sensor chip can be inserted into a deformable anisotropically conductive material. This deformable anisotropically conductive material can be an adhesive. The adhesive can optionally not yet be cured. The sensor chip can be temporarily fixed in the deformable anisotropically conductive material.

[0086] In step e), electrically conductive connections are created between the contact pads of the sensor chip and the conductor structures of the substrate using the anisotropically conductive material. The sensor chip is preferably pressed into the anisotropically conductive material in such a way that some conductive particles of the anisotropically conductive material each establish a locally limited electrical contact between the contact pads and the conductor structures. In addition, the anisotropically conductive material can optionally be cured. Curing can occur in particular when a reactive polymer precursor (e.g., a polymer resin) is used as a matrix for the anisotropically conductive material. Depending on the polymer precursor used, curing can be induced, for example, by oxygen, moisture, heating, or exposure to light, such as UV light. Curing can improve the strength of the mechanical connection.

[0087] Optionally, steps d) and e) can be performed together. This means that while the sensor chip is positioned on the anisotropically conductive material, the electrical and mechanical contact is established simultaneously. The mechanical contact can preferably be full-surface, meaning that the first side of the sensor chip is completely covered with anisotropically conductive material.

[0088] The anisotropically conductive material mechanically secures the sensor chip to the substrate and simultaneously seals the at least one trimming structure on the sensor chip so that it is protected from environmental influences. Outside the areas where the anisotropically conductive material is compressed between the contact pads and the conductor structures, the anisotropically conductive material preferably has an electrically insulating effect. After step e), the entire space between the sensor chip and the substrate is preferably filled with anisotropically conductive material. Short description of the characters

[0089] In the following, the invention will be illustrated by means of concrete embodiments with the aid of drawings.

[0090] Figure 1 shows a sensor element according to the state of the art.

[0091] Figure 2 shows a possible manufacturing method for a sensor chip according to the invention.

[0092] Figure 3shows schematically a sensor element according to the invention and the arrangement on a substrate.

[0093] Figure 4 shows a possible embodiment of the method according to the invention for producing a sensor module.

[0094] Figure 5 shows a possible embodiment of the sensor module according to the invention, wherein no insulating layer is arranged on the resistance structure. List of reference symbols

[0095] 1 Sensor chip 2 Sensor element 5 Sensor module 10 Electrically insulating carrier 11 Dielectric layer 12 Conductive layer 20, 20' Contact pads 21, 21' Contact patches 30 Resistor structure 35 Trimming structure 36 Trimming point 40 Anisotropic conductive material 41 Conductive particles 42 Insulating matrix 45 Solder connection 50 Insulating layer 51 Cover layer 60 Substrate 70, 70' Conductor structures

[0096] An additional (x) indicates prior art embodiments throughout.

[0097] In Figure 1 a sensor element (2x) from the prior art is shown. Two contact pads (20x, 20'x) are arranged on an electrically insulating carrier (10x). A resistance structure (30x) extends from the first contact pad (20x) to the further contact pad (20'x). The resistance structure (30x) contains a trimming structure (35x). The trimming structure (35x) has been manipulated at a trimming point (36x), e.g., by means of laser ablation. The resistance structure is provided with an insulating layer (50x), for example, a glass layer, wherein the trimming structure (35x) is not covered by the insulating layer. The entire resistance structure 30x containing the trimming structure 35x is covered with a covering layer (51x). The covering layer (51x) can, for example, be a further glass layer.

[0098] The prior art sensor element (2x) designed in this way can be fixed to a substrate, for example, by means of solder joints (45x, 45'x) via the contact pads (20x, 20'x). A disadvantage of the prior art is that the trimming structure must be covered with an additional covering layer (51x), in particular a glass layer, after trimming and before installation in a sensor module. This requires an additional process step and, in the case of a glass layer, also an increased energy requirement, since the glass must be fired. It would be desirable if this firing step could be omitted, since the already set resistance of the resistor structure can also be influenced by it.

[0099] In Figure 2A method for producing a sensor chip (1) is described, as can be used in the invention. In step 2a), contact pads (20, 20') are arranged on the first side of an electrically insulating carrier (10). A resistance structure (30) extends from a first contact pad (20) to a further contact pad (20'). The resistance structure (30) contains a trimming structure (35). In this case, the above-mentioned electrically conductive elements (20, 20', 30, 35) are preferably thin-film elements. The region of the resistance structure located between the dashed lines y and z is preferably meander-shaped and is mainly responsible for temperature measurement. In step b), an insulating layer (50) is applied to the first side of the electrically insulating carrier (10), e.g. by spin coating with a polyimide.In step c), the insulating layer is at least partially removed in the region of the contact pads (20, 20') and in the region of the trimming structure (35). In step d), contact patches (21, 21') are applied to the contact pad regions freed from the insulating layer. In step e), the resistance structure (30) is trimmed to a nominal resistance via the trimming structure (35). The trimming points (36) are shown as circular in the figure; these can be generated, for example, with a laser and sever the bridges of the trimming structure. Optionally, parts of the electrically insulating carrier or only parts of the trimming structure can be removed in the region of the trimming points. Optionally, the order of steps d) and e) can also be reversed. The sensor chip (1) obtainable by the steps a) to e) shown can be used in a sensor element or sensor module according to the invention.

[0100] In Figure 3An embodiment of a sensor element (2) according to the invention is shown schematically. Contact pads (20, 20') are arranged on the electrically insulating carrier (10), between which contact pads a resistance structure (30) containing a trimming structure (35) extends. In one possible embodiment, as shown here, the electrically insulating carrier (10) comprises a dielectric layer (11) arranged on a conductive layer (12). Optionally, the trimming structure (35) can have a trimming point (36). The resistance structure (30) is provided with an insulating layer (50) at least in the region outside the trimming structure (35). The combination of the components (10, 20, 30, 35 and 50) without the anisotropically conductive material (40) can also be referred to as a sensor chip (1). An anisotropically conductive material (40) is arranged on the sensor chip (1).The anisotropically conductive material (40) contains conductive particles (42) embedded in an insulating matrix (41). The anisotropically conductive material (40) covers the resistance structure (30) including the trimming structure (35). The trimming structure (35) can have a trimming point (36) with which the resistance structure (30) was adjusted to the nominal resistance. In particular, the trimming structure (35), on which no insulating layer (50) is arranged, is closed by the anisotropically conductive material (40) and thus protected from environmental influences. The sensor element (2) according to the invention can be arranged, for example, on the first surface of a substrate (60). Conductor structures (70) can be arranged on the first surface of the substrate.

[0101] Figure 4shows a possible method for producing a sensor module (2) according to the invention. First, a sensor chip (1) is provided. The sensor chip comprises an electrically insulating carrier (10) on which contact pads (20, 20') are arranged on a first side. A resistance structure (30) extends from a first contact pad to a further contact pad. The resistance structure (30) comprises a trimming structure (35). The resistance structure (30) is covered with an insulating layer (50), at least outside the trimming structure (35). At least two conductor structures (70, 70') are arranged on a first surface of a substrate (60). An anisotropically conductive material (40) is arranged on the substrate (60) in the region of two adjacent conductor structures to be contacted, e.g. in the form of a layer, in particular a layer of an anisotropically conductive adhesive as is known in the prior art.

[0102] The sensor chip (1) is positioned over the substrate (60) such that the first side of the electrically insulating carrier with the contact pads (20, 20') arranged thereon is aligned towards the substrate (60). The sensor chip (1) is then arranged on the anisotropically conductive material (40). The trimming structure (35) is closed by the anisotropically conductive material (40). Simultaneously or subsequently, the anisotropically conductive material (40) is pressed together between the contact pads (20, 20') and the conductor structures (70, 70'), e.g., using a heated stamp. The conductive particles (41) in the anisotropically conductive material (40) establish local electrical contact in the gap between the conductor structures (70, 70') and the contact pads (20, 20'). In case the anisotropically conductive material (40) contains a polymer precursor, the anisotropically conductive material can cure.The height h 1 indicates the total height of the contact pads, on which optional contact patches (21, 21') are arranged. The height h 2 indicates the height of the resistance structure. It can be seen that h 1 is greater than h 2 . This allows pressure to be exerted locally on the anisotropically conductive material in the area of ​​the contact pads.

[0103] Figure 5 shows a sensor element analogous to Figure 4b ) with the difference that the sensor module in Figure 5 has no insulating layer (50). In this embodiment, the anisotropically conductive material (40) directly covers both the resistance structure (30) and the trimming structure (35) with the trimming point (36).

Claims

1. A sensor element (2) having a sensor chip (1) and an anisotropically conductive material (40), wherein the sensor chip (1) has a. an electrically insulating carrier (10) comprising a first side and a second side lying opposite the first side, b. at least two contact pads (20, 20') arranged on the first side of the electrically insulating carrier (10), and c. a resistance structure (30) on the first side of the electrically insulating carrier (10), which extends from a first contact pad (20) to at least one additional contact pad (20'), wherein the resistance structure contains at least one trim structure (35), characterized in that an anisotropically conductive material (40) is arranged on the first side of the electrically insulating carrier (10), at minimum on at least the one trim structure (35).

2. The sensor element according to claim 1, wherein the resistance structure (30) is at least partially or completely covered with an insulating layer (50) at minimum in the area outside of the at least one trim structure (35).

3. The sensor element according to one of claims 1 or 2, wherein the insulating layer (50) does not at least partially cover the at least one trim structure (35).

4. The sensor element according to one of claims 1 to 3, wherein the insulating layer (50) contains a dielectric material selected from the group consisting of polymers, glass, ceramics, and glass ceramics.

5. The sensor element according to one of claims 1 to 4, wherein the surface of the resistance structure (30) of the sensor chip (1) is at least partially coated with a first inorganic passivation layer, wherein the first inorganic passivation layer preferably has an oxide, a nitride, or an oxide-nitride composite material.

6. The sensor element according to one of claims 1 to 5, wherein the anisotropically conductive material (40) is selected from the group containing anisotropically conductive two-component adhesives, anisotropically conductive one-component adhesives, anisotropically conductive hot melt adhesives and anisotropically conductive films, and wherein the anisotropically conductive material contains deformable or nondeformable electrically conductive particles.

7. The sensor element according to one of claims 1 to 6, wherein the at least one trim structure (35) of the resistance structure (30) has at least one area in which a portion of the at least one trim structure (35) is cut through or partially removed in the material.

8. The sensor element according to one of claims 1 to 7, wherein the at least one trim structure (35) coated with the anisotropically conductive material (40) is not at least partially coated by at least one additional passivation layer or a cover layer.

9. The sensor element according to one of claims 1 to 8, wherein at least one contact pad (20, 20') has at least one contact patch (21, 21'), wherein the at least one contact patch (21, 21') has a surface area of 0.01 mm2 or less, and / or the distance from edge to edge between two directly adjacent patches on a contact pad measures at most 300 µm.

10. The sensor element according to one of claims 1 to 9, wherein the electrically insulating carrier of the sensor chip is flexible.

11. The sensor element according to one of claims 1 to 10, wherein the first side of the sensor chip has a surface area that measures at most 1 mm2 and / or the sensor chip has a thickness of at most 200 µm.

12. A sensor module (5), with a. a sensor element (2) according to one of claims 1 to 11, with a sensor chip (1) and an anisotropically conductive material (40), b. a substrate (60) having a first surface with at least two conductor structures (70, 70') arranged thereupon, wherein the sensor element (2) is arranged on the substrate (60) with the anisotropically conductive material (40) toward the first surface of the substrate (60), characterized in that electrically conductive connections are formed between the contact pads (20, 20') of the sensor chip and the conductor structures (70, 70') of the substrate (60) via the anisotropically conductive material (40).

13. The sensor module according to claim 12, wherein the anisotropically conductive material (40) at least partially or completely coats, in particular seals, and very especially preferably hermetically seals, the at least one trim structure (35).

14. The sensor module according to one of claims 12 or 13, wherein no structures are present in the area between the contact pads (20, 20') that are higher than the combined height of the conductor structures (70, 70') on the substrate and the contact pads (20, 20') with optional contact patches (21, 21').

15. A method for manufacturing a sensor module (5), in particular according to one of claims 12 to 14, comprising at least the following steps: f) Providing a substrate (60) having a first surface, wherein a conductor structure (70) is arranged on this first surface, g) Providing a sensor chip (1) according to one of claims 1 to 11, h) Applying an anisotropically conductive material (40) to the first side of the electrically insulating carrier (10) of the sensor chip (1) or on the first surface of the substrate (60), i) Positioning the sensor chip (1) on the substrate (60), so that the resistance structure (30) is oriented toward the substrate, and the anisotropically conductive material (40) is present between the sensor chip (1) and the substrate (60), and j) Establishing electrically conductive connections between the contact pads (20, 20') of the sensor chips and the conductor structures (70, 70') of the substrate (60) via the anisotropically conductive material (40).

16. The method according to claim 15, wherein the anisotropically conductive material (40) at least partially or completely seals the at least one trim structure (35).

17. The method according to one of claims 15 or 16, wherein the sensor chip in step b) has a trim point (36) in the area of the at least one trim structure (35).