Anisotropic conductive adhesive bonding for RTD

Abstract

The invention relates to a sensor element having a sensor chip and an anisotropic conductive material, wherein the sensor chip has: an electrically insulating carrier; at least two contact pads arranged on the first side of the electrically insulating carrier; and a resistive structure on the first side of the electrically insulating carrier, the resistive structure extending from the first contact pad to the at least one further contact pad, where the resistive structure includes at least one trimming structure. On the first side of the electrically insulating carrier, the anisotropic conductive material is disposed at least indirectly or directly on the at least one trimming structure.

Description

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

[0002] Resistance sensors made of platinum, for example, have long been known in the prior art. Such resistance sensors have a temperature-sensitive resistor structure arranged on an electrically insulating carrier. Here, the resistance structure is contacted via contact pads. Usually, sensors are sold with precisely defined nominal resistance and temperature coefficient. However, it is difficult to directly manufacture sensors with a nominal resistance defined in this way. Since the resistance structure is affected by the manufacturing process, the resistance of the originally manufactured sensor has a certain fluctuation range. In order to adjust the sensor to the nominal resistance as accurately as possible, a sensor with a resistance slightly lower than the nominal resistance is usually made, and then the sensor is adjusted to the nominal resistance by increasing the resistance. Adjusting the resistance of the resistance structure to the nominal resistance is also called trimming. For this purpose, the resistance of the sensor structure can then be changed in a specially formulated trimming area by extending the distance of the conductor line or separating the parallel resistors. As a result, the resistance is increased. In the prior art, the trimming process is usually achieved by removing part of the conductor line structure in the trimming area by material processing using laser radiation. In order to protect the conductor lines in the trimming area from environmental influences, the trimming area must be closed after trimming. This is usually achieved by subsequently sealing the trimmed region with an isotropic, electrically insulating cover layer made of glass, ceramic, glass ceramic or polymer. This has the disadvantage that the resistance of the already trimmed resistor structure can change again, in particular when applying and firing the glass, ceramic or glass ceramic.

[0003] It would be desirable to be able to dispense with the application of such a covering layer after trimming before installing the sensor in its final application.

[0004] Furthermore, there is a trend towards miniaturization of sensors, in particular resistance sensors. For example, such miniaturized sensors require only a small amount of space to be mounted on circuit boards in the semiconductor industry. Here, conventional assembly and connection technologies have reached their limits. Usually, resistance sensors, in particular resistance sensors in the form of surface mount devices (SMDs), are fastened to conductor tracks of a substrate, such as a printed circuit board (PCB), by soldering. However, for very small sensors, over-soldering can occur, resulting in short circuits between the contacts. It would be desirable if resistance sensors, in particular miniaturized resistance sensors, could be fastened to a substrate in such a way that the risk of short circuits is reduced.

[0005] The object of the present invention is to provide a sensor element in which a special sealing of the trimming structure, for example with a glass layer or a ceramic layer, can be omitted. In particular, the object of the present invention is to provide a sensor element in which the trimming structure or the trimming location does not have to be sealed before the sensor chip is installed in the sensor module.

[0006] Another preferred object is to provide a sensor element which can be simply fastened to a substrate having conductor structures which are closely adjacent to one another.

[0007] Another object of the present invention is to provide a simplified method for producing a sensor module, in particular a simplified method for producing a sensor module comprising a miniaturized sensor chip which is contacted with conductor structures which are closely adjacent to each other. In particular, the risk of short circuits should be reduced.

[0008] The subject matter of the independent claims solves at least one of the objects. The subject matter of the dependent claims are preferred embodiments of the invention.

[0009] In a first aspect, the invention relates to a sensor element having a sensor chip and an anisotropic conductive material, wherein the sensor chip has: 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 a first side of the electrically insulating carrier, and c) a resistive structure on the first side of the electrically insulating carrier, the resistive structure extending from the first contact pad to at least one further contact pad, wherein the resistive structure comprises at least one trimming structure, It is characterized in that, on the first side of the electrically insulating carrier, the anisotropic conductive material is arranged at least on at least one trimming structure. The anisotropic conductive material can be arranged on at least one trimming structure indirectly or directly.

[0010] The sensor element has a sensor chip and an anisotropic conductive material. Preferably, the anisotropic conductive material is therefore not part of the sensor chip. The sensor chip can be a resistance sensor, in particular a resistance temperature sensor (RTD), having a metal resistance structure. The resistance sensor can be, for example, a PTC. The metal resistance structure can, for example, have platinum, palladium, nickel, aluminum or other metals, or consist of these metals. Optionally, the metal resistance structure can have an alloy or consist of an alloy. In a possible embodiment, the alloy can be an aluminum alloy, for example, the alloy contains 0.5-2 weight percent 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, the sensor chip can be a resistive heater with a precisely adjusted resistance, in particular a resistive heater with a meandering structure.

[0012] In another preferred application, the sensor element is a complex system consisting of multiple electronic components arranged on an electrically insulating carrier, the sensor element comprising a resistor structure having at least one trimming structure, wherein the anisotropic conductive material covers the at least one trimming structure, and the at least one trimming structure preferably comprises a trimming position.

[0013] Particularly preferably, the resistor structure comprises at least one trimming structure. Preferably, the trimming structure is modified (ie, trimmed) by ablation (eg, by means of laser radiation). The modified region of the at least one trimming structure is also referred to as a trimming location.

[0014] In a particularly preferred embodiment, the sensor chip may be a sensor as described in WO2021047948A1, in particular a sensor in the form of a temperature sensor. Very particularly preferably, the sensor chip is a sensor as described in WO2021047948A1. Figure 1 and Figure 2 And the sensor chip disclosed in the related description.

[0015] Preferably, the anisotropic conductive material comprises an electrically insulating matrix in which the conductive particles are dispersed. In the context of the present invention, the conductive particles also include conductive elements, such as cylindrical conductive elements, which are firmly embedded in the electrically insulating matrix and extend through the anisotropic conductive material in a preferred direction. Preferably, the electrically insulating matrix comprises or consists of an organic material.

[0016] Preferably, the electrically insulating matrix of the anisotropic conductive material can be selected from organic polymers (such as epoxides) and silicones. Very particularly preferably, the electrically insulating matrix of the anisotropic conductive material contains or consists of an epoxy resin. Anisotropic conductive materials, in particular anisotropic conductive adhesives, are basically known to those skilled in the art in the field of assembly and connection technology and are commercially available. The skilled person is able to select and use suitable materials.

[0017] In particular, anisotropic conductive materials can be understood as anisotropic conductive adhesives, anisotropic conductive films or tapes. Preferably, anisotropic conductive adhesives and anisotropic conductive films contain polymers or polymer precursors filled with conductive particles. Particularly preferably, the polymer is a thermosetting polymer, which can be obtained by crosslinking a polymer precursor or a polymer system. In addition, the polymer precursor can be a monomer or an oligomer. In the scope of the present invention, anisotropic conductive materials can be understood as both polymer precursors and cured or crosslinked polymer materials, such as adhesives.

[0018] The anisotropic conductive material can be selected from the group comprising the following items: anisotropic conductive two-component adhesive, anisotropic conductive one-component adhesive, anisotropic conductive hot melt adhesive and anisotropic conductive film. The anisotropic conductive film can be, for example, a tape filled with conductive particles (e.g., metal particles, in particular silver particles). Advantageously, the anisotropic conductive material contains deformable or non-deformable conductive particles. An example of a deformable particle is carbon particles, in particular graphite particles. Preferably, the filling degree of the conductive particles in the anisotropic conductive material is selected so that the conductive particles do not form any electrical contact (i.e., percolation path) as long as there is no mechanical action from the outside. In some embodiments of the present invention, the tape can also be used as an anisotropic conductive material, which includes conductive areas and insulating areas perpendicular to the surface of the tape. Such tapes are also called zebra rubber or conductive rubber. In the scope of the present invention, anisotropic conductivity refers in particular to anisotropic conductivity, which may also include thermal conductivity.

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

[0020] The electrically insulating carrier has a first side and a second side opposite to the first side. Preferably, the first side and the opposite second side of the electrically insulating carrier are synonymous with the first side and the second side of the sensor chip. Preferably, the first side of the electrically insulating carrier has a width of at most 1 mm. 2 In particular, the first side of the electrically insulating carrier has an area of ​​at most 0.3 mm 2 area, and very preferably has an area of ​​at most 0.2 mm 2area. Therefore, usually, the first side of the sensor chip predetermined by the first side of the electrically insulating carrier also has a specified area. The electrically insulating carrier has a dielectric material on at least one side, in particular the first side (on which the contact pad and the resistor structure are arranged). Optionally, both sides of the electrically insulating carrier have a dielectric material. Preferably, the dielectric material is designed as a continuous layer. Optionally, the dielectric material can be arranged on a conductive material or on a dielectric material. The conductive material can be, for example, a metal or a doped semiconductor. In the case where the dielectric material of the electrically insulating carrier is arranged on the conductive material, it can also be referred to as a multilayer structure of the electrically insulating carrier. Preferably, the conductive material of the electrically insulating carrier is not in contact with the contact pad or the resistor structure. In one possible design scheme, the electrically insulating carrier consists of a dielectric material.

[0021] In a possible design of the present invention, the electrically insulating carrier is composed of one or more dielectric materials. For example, the dielectric material of the entire electrically insulating carrier or part of the electrically insulating carrier can be selected from the group comprising the following items: glass, ceramic, glass ceramic and polymer. Glass can be selected from silicate glass. For example, ceramic can be selected from oxide ceramics, nitride ceramics or carbide ceramics. For example, oxide ceramics can include silicon oxide, aluminum oxide, titanium oxide and zirconium oxide, and mixtures of these oxides. Nitride ceramics can include metal nitrides, and preferably, can be selected from the group comprising the following items: titanium nitride, silicon nitride and aluminum nitride. For example, polymers can include polyimide or silicone.

[0022] In an advantageous embodiment of the invention, the electrically insulating carrier comprises or consists of an inorganic material. Preferably, the inorganic material comprises silicon and silicon compounds. In a particularly preferred embodiment of the invention, the electrically insulating carrier may comprise a silicon wafer, which is provided with a layer of dielectric material at least on a first side. The silicon wafer may be doped or undoped. Preferably, the dielectric layer on the silicon wafer comprises or consists of a metal oxide (e.g. silicon oxide or aluminum oxide). The advantage of using a silicon wafer is that the silicon wafer has a particularly low surface roughness, which is particularly advantageous for very small sensors with a thin resistive layer. In the case where the electrically insulating carrier comprises a conductive material (e.g. a metal plate or a doped semiconductor wafer), it is preferably noted that the dielectric material is present at least on the first side, in particular in the form of a continuous layer, so that conductive structures attached to the first side (such as resistive structures or contact pads) do not short-circuit.

[0023] Preferably, the electrically insulating carrier is designed as a thin plate or disk, for example a rectangular plate. Optionally, the sensor chip and therefore also the electrically insulating carrier can be flexible. In a preferred embodiment, the sensor chip is flexible and can be bent to a radius of curvature of at least 5 mm, preferably at least 2 mm, preferably at least 1 mm, wherein the relative difference (where d represents Delta or Δ) of the specific resistance (dR / R(0)) of the resistor structure before and after bending is preferably no more than 2%, in particular no more than 1%, and very particularly preferably no more than 0.5%.

[0024] This flexibility of the sensor chip can be measured as follows. The sensor chip is bonded to a polyimide film (Kapton®, 25µm) to determine the flexibility of the sensor chip. Prior to bonding, the surface of the Kapton film is activated by using a corona discharge treatment. A cyano adhesive (MINEA, quick-drying adhesive) is applied to the back of the sensor chip and the sensor chip is pressed onto the polyimide film during the reaction time of the adhesive. Subsequently, the polyimide film is wound around a cylindrical rod with the sensor chip facing outward. The diameter of the rod is selected in the range of 0.25 mm to 10 mm. During winding, 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 diameter of the rod. The duration of the maximum bending is set to approximately one second. Therefore, preferably, the winding or bending consists of a bending process and an unbending process. Before and after each bending cycle, the relative difference in the specific resistance dR / R(0) (where d represents delta or Δ) of the electrical structure is measured. The sensor chip can be considered flexible as long as the radius of curvature is not less than a minimum radius Rm, which is defined as the radius at which dR / R(0) has a value of 2%, in particular 1% and very particularly preferably 0.5%.

[0025] In addition, the sensor chip has at least two contact pads, which are arranged on the first side of the electrically insulating carrier. The contact pad can be understood as a locally applied conductive layer, for example, which can make stable electrical and mechanical contact with an electrical conductor or metal wire. The contact can be made by means of metal wire welding or metal wire bonding. Preferably, each of the at least two contact pads can occupy up to 25% of the area of ​​the first side of the electrically insulating carrier, or particularly preferably up to 10%. For example, the contact pads can be arranged at opposite ends or at the same end of the first side of the electrically insulating carrier. The farther the contact pads are from each other, the lower the risk of a short circuit at the contact point when in contact. Larger contact pads have the advantage of being easier to contact. The thickness of the contact pad on the electrically insulating carrier is preferably at least 100nm, in particular at least 200nm and very particularly preferably at least 500nm. In addition, the thickness of the contact pad can be at most 5μm, in particular at most 2μm and very particularly preferably at most 1μm.

[0026] The contact pads can generally be wider than the conductor structure of the resistor structure in order to be able to make better contact with the metal line or cable. In the case where the contact pads are not widened compared to the resistor structure, the ends of the resistor structure can preferably also be understood as contact pads.

[0027] In a possible design, the contact pad is in contact with a through hole (English: via), so that a metal wire or cable can be attached to the second side of the electrically insulating carrier.

[0028] Preferably, at least one contact pad may have at least one contact patch. Particularly preferably, the contact patch is in direct electrical contact with the contact pad and the contact patch is arranged on the contact pad. Preferably, the contact patch is a raised, spatially limited metal layer (also called a Fleck or in English: patch). The contact patch may be constructed to improve the electrical and mechanical contact of the contact pad and may be arranged on the contact pad. Preferably, the contact patch occupies less than 10% of the area of ​​the first side of the electrically insulating carrier. Preferably, the contact patch occupies less than 40% of the area of ​​the first side of the contact pad, even more preferably less than 25%. In order to determine the area of ​​the contact patch, it is preferred that the projection of the contact patch on the contact pad is perpendicular to the first side of the electrically insulating carrier in a top view.

[0029] Particularly preferably, two to sixteen contact patches, in particular two to eight contact patches, are arranged on the contact pad. In addition, the contact patch can be manufactured by depositing metal on the contact pad by electroplating processes such as electrochemical (ECD) and power-free (ELD). Optionally, the contact patch can also be manufactured by other processes (for example, thick film processes including printing). Preferably, the contact patch has a different metal or alloy from the contact pad located below. In the case where there is a layer that hinders metal deposition, in particular an insulating layer, on the contact pad, the layer can be removed point by point before metal deposition, such as using a laser, and then the contact patch can be applied to the exposed position by means of the above method, in particular an electroplating process. Preferably, the contact patch can contain or consist of a metal selected from the group comprising the following items: nickel, gold and silver or other conductive materials. A layer system manufactured by electroplating is also possible. For example, other possible methods for applying the contact patch are screen printing or pad printing. Preferably, the thickness of the contact patch is at least 2μm, in particular at least 5μm, and very particularly preferably at least 10μm. Furthermore, preferably, the thickness of the contact patch is at most 30 μm, in particular 20 μm, and in particular at most 15 μm. With a contact patch having a thickness in this thickness range, preferably good pressure can be applied to the anisotropic conductive material and good contact can be established. Preferably, the contact patch projects beyond the resistive structure of the sensor chip or the optionally present insulating layer by 5 μm to 20 μm, in particular 5 μm to 10 μm. Thus, preferably during the manufacture of the sensor module, the contact patch can exert a local pressure on the anisotropic conductive material sufficient to establish an electrical connection without causing a short circuit outside the contact patch.

[0030] Advantageously, the area of ​​the contact patch is 0.1 mm 2 or smaller, especially 0.01mm 2 or less, and particularly preferably 0.005 mm 2 or less. Preferably, the cross-section of the contact patch in a plane parallel to the electrically insulating carrier may be in the range of 10 μm to 100 μm. Furthermore, the distance from edge to edge between two adjacent patches on the contact pad may be in the range of 1 μm-300 μm. In a preferred embodiment, the maximum cross-section of the contact patch in a plane parallel to the electrically insulating carrier is larger than the contact area located underneath the contact pad. Preferably, the contact patch extends beyond the optionally present insulating layer, or in other words, the contact patch may thus have a mushroom shape. Alternatively, the contact patch may have a constant diameter, or may not widen upwards.

[0031] According to the invention, a resistor structure is arranged on a first side of an electrically insulating carrier, the resistor structure extending from a first contact pad to at least one further contact pad. In the context of the invention, a resistor structure can be understood as a conductor, in particular a metal conductor, having a temperature-dependent change in resistance characteristics. In a preferred design, the resistor structure has a metal or consists of a metal. Preferably, the metal can be selected from the group consisting of platinum, nickel, aluminum, palladium, gold, silver and copper and an alloy containing at least one of these metals as a main component. The main component of the alloy can be understood as the element with the highest weight proportion. Further preferably, the alloy can contain at least one of rhodium, copper, platinum, nickel, aluminum, palladium, gold, silver and copper as further alloying elements.

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

[0033] Preferably, the thickness of the resistor structure on the electrically insulating carrier is at least 100 nm, in particular at least 200 nm and very particularly preferably at least 500 nm. Furthermore, the thickness of the resistor 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 pad and the resistor structure can be obtained separately or jointly from a planar conductive layer, in particular a metal layer, by means of subsequent structuring. The layer can be produced by means of thin-film technology or thick-film technology. Optionally, the resistor structure and the contact pad contain the same material or consist of the same material.

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

[0036] The resistor structure comprises at least one trimming structure. Optionally, the resistor structure comprises two or more trimming structures. Preferably, the trimming structure is a conductive structure, the resistance of which can be changed, in particular increased, by manipulating the material. In particular, at least one trimming structure can be manipulated so that the resistance of the entire resistor structure including the trimming structure corresponds to a determined nominal resistance. In particular, the material manipulation can be stripping. Preferably, the stripping can be performed using a method selected from the following items: etching, milling, grinding and laser ablation. If a nominal resistance is mentioned in the scope of the present invention, it will be clear to the technician that this is a nominal value and that the actual resistance (for example, due to production fluctuations) can fluctuate within a tolerance range around the nominal resistance. For example, for a platinum resistor structure, a tolerance range can be specified in a standard (for example, a DIN standard). In particular, at least one trimming structure is electrically connected in series or in parallel with the remaining area of ​​the resistor structure.

[0037] At least one trimming structure can be designed so that its resistance can be changed stepwise or continuously. Stepwise trimming can also be referred to as digital trimming, while continuous trimming can also be referred to as analog trimming. For example, a structure that allows the stepwise adjustment of the resistance is a conductor line structure that is divided into parallel single strands, which conductor line structure can be processed so that the individual conductor lines of the parallel conductor lines can be separated, thereby reducing the conductor cross section. For example, a structure that allows the continuous adjustment of the resistance can be a strip that can be processed so that the distance over which the current must flow is continuously extended, or so that the conductor cross section is reduced, for example by slotting in the strip. Preferably, the resistance structure comprises at least one trimming structure for analog trimming and at least one trimming structure for digital trimming, because with this arrangement the resistance can be adjusted particularly accurately. Very particularly preferably, both trimming structures have trimming positions.

[0038] In an embodiment of the invention, the sensor element has an insulating layer, wherein preferably the insulating layer is arranged on a first side of the electrically insulating carrier. Preferably, the resistance structure is partially or completely covered by the insulating layer at least in the region outside the at least one trimming structure. In a preferred embodiment, at least one trimming structure is at least partially not covered by the insulating layer. Optionally, the contact pad may also not be covered by the insulating layer. As a result, the material of the trimming structure can be manipulated, in particular by means of laser ablation. For example, the insulating layer can have a groove in the region of the trimming structure. The groove (also called opening or window) can be generated directly when the insulating layer is manufactured, or the insulating layer is first manufactured to be planar and the groove is subsequently generated in the insulating layer.

[0039] The insulating layer may include or consist of a dielectric material selected from the group consisting of polymer, mixed polymer, glass, ceramic and glass ceramic. Preferably, the polymer of the insulating layer includes at least one material selected from the group consisting of polyimide, parylene and epoxy resin.

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

[0041] In a possible design of the present 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. Preferably, the inorganic passivation layer is not equivalent to an insulating layer. Preferably, the inorganic passivation layer is used to protect the resistor structure from corrosion and contamination.

[0042] Preferably, both the electrically insulating carrier and the resistor structure are covered by a first inorganic passivation layer. In a possible embodiment of the invention, the first inorganic passivation layer has holes or defects caused by the trimming in the region of at least one trimming structure, in particular in the region of the trimming location. Optionally, the material of the first inorganic passivation layer removed in the region of the holes or defects can be deposited around these holes or defects and used there as a passivation layer. Thus, parts of the trimming structure that were initially exposed due to the trimming process can advantageously be passivated again in the same process step.

[0043] Preferably, the first inorganic passivation layer comprises an oxide, a nitride or an oxide-nitride composite material. The oxide may be a metal oxide and is preferably selected from the group consisting of silicon oxide, aluminum oxide and titanium oxide. The nitride may be a metal nitride and is 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 consisting of at least one oxide layer and at least one nitride layer stacked on top of each other. Preferably, the first inorganic passivation layer has an average thickness in the range of 0.4 μm to 2 μm. If the first inorganic passivation layer has an oxide-nitride composite material, in particular a layer material, preferably, the oxide layer and the nitride layer each have an average thickness of at least 0.4 μm.

[0045] In particular, the inorganic passivation layer is electrically insulating and / or serves as a moisture barrier, for example against atmospheric humidity.

[0046] According to the invention, on the first side of the electrically insulating carrier, the anisotropic conductive material can be arranged at least on at least one trimming structure indirectly or directly. Indirectly means that another material, in particular a layer, is present between the at least one trimming structure and the anisotropic conductive material. In particular, the other material can be a first inorganic passivation layer. Directly here means that at least one trimming structure is in contact with the anisotropic conductive material. Preferably, the anisotropic conductive material is arranged on at least one trimming structure so that the anisotropic conductive material encloses, in particular hermetically encloses at least one trimming structure. As a result, the trimming structure can be well protected from environmental influences. Furthermore, preferably, the entire resistor structure and the contact pads are covered by the anisotropic conductive material. The anisotropic conductive material can be present in the form of a layer. If an insulating layer is present on the first side of the carrier, the anisotropic conductive material is arranged on this layer.

[0047] Preferably, at least one trimming structure has at least one region in which a portion of the trimming structure is cut and / or in which material is partially removed in a continuous region of the trimming structure. The cut or removed region of the trimming structure is also referred to as the trimming location.

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

[0049] In a particularly preferred embodiment of the invention, at least one trimming structure covered with anisotropic conductive adhesive is at least partially or completely not covered by at least one further passivation layer or cover layer on the side facing away from the electrically insulating carrier. In particular, at least no glass layer or ceramic layer or no polymer layer is arranged 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 other areas of the first side (e.g. on other parts of the resistor structure) there is a polymer layer or a glass layer or a ceramic layer as a cover layer or passivation layer.

[0050] In the case of trimmed sensor elements known from the prior art, in particular Pt-RTDs, the trimming is usually carried out via windows in one or more passivation layers or cover layers or before the passivation layers or cover layers are applied. In the prior art, the passivation layers are usually made of glass or glass ceramics.

[0051] Preferably, the first side of the electrically insulating carrier and thus preferably also the first side of the sensor chip has a thickness of at most 1 mm. 2 In particular, the first side of the sensor chip has an area of ​​at most 0.3 mm 2 and very particularly preferably at most 0.2 mm 2 The sensor chip can also have a thickness of at most 200 μm, preferably at most 100 μm and very particularly preferably at most 50 μm. In particular, the thickness is determined perpendicularly to the surface on which the resistor structure is arranged. The sensor chip can be manufactured, for example, using a photolithography process, such as is used in semiconductor production. The advantage of a small sensor chip thickness is that a particularly flat sensor module that requires less space can be realized. In addition, a sensor chip with a smaller thickness has a lower mass, whereby the response time can be improved.

[0052] Preferably, the sensor chip has a nominal resistance. For example, the nominal resistance at 0°C may be 50Ω, 100Ω, 200Ω, 250Ω, 1000Ω, 2500Ω, 5000Ω or 10000Ω. In the case where the resistance of the resistance structure is less than the nominal resistance after the resistance structure is generated, the resistance may be adjusted to the nominal resistance. Preferably, adjustment to a narrow tolerance range close to the nominal resistance is performed via at least one trimming structure, also referred to as trimming. Preferably, the sensor resistance is adjusted within a tolerance range of the nominal resistance according to IEC 751 / EN 60751 or 1 / 10B class. The trimming of at least one trimming structure may be performed by ablation (e.g., by laser ablation). Optionally, the trimming may be omitted in the case where the resistance of the resistance structure from a previous production step already corresponds to the nominal resistance.

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

[0054] Alternatively, contact patches may be applied to the contact pads, for example using an electroplating process or by means of printing.

[0055] In an example, the thin film process for applying the conductive layer may be selected from physical vapor deposition (PVD) and sputtering. The thick film process may for example be a printing process, such as a screen printing process.

[0056] The structuring of the electrically conductive layer can be performed by a photolithographic process or by means of an ablation process (for example laser ablation).

[0057] A particularly preferred method for manufacturing a sensor chip may have the following steps. First, contact pads are arranged on a first side of an electrically insulating carrier. A resistive structure extends from the first contact pad to another contact pad. The resistive structure includes at least one trimming structure. Preferably, the resistive structure is configured to be meander-shaped at least in one section. In a next step, an insulating layer is applied to the first side of the electrically insulating carrier, for example by spin coating polyimide. Subsequently, the insulating layer in the region of the contact pads and in the region of at least one trimming structure is at least partially removed. Then, a contact patch is applied to the contact pad region detached from the insulating layer. In a next step, the resistive structure is trimmed to a nominal resistance via at least one trimming structure. For example, the trimming position generated in this process is generated using a laser, and the individual bridging portions of the trimming structure can be cut. Optionally, additional portions of the electrically insulating carrier can be removed in the region of the trimming position or only portions of the trimming structure can be removed. Optionally, the steps for manufacturing the contact patch and the trimming step can exchange their order of arrangement. The sensor chip obtainable by the described steps can be used in a sensor element or a sensor module according to the present invention.

[0058] In a second aspect, the invention relates to a sensor module having a sensor element according to the invention and a substrate having a first surface on which a conductor structure is arranged. The sensor element comprises a sensor chip and an anisotropic conductive material. In particular, the sensor chip comprises: an electrically insulating carrier having a first side and a second side opposite the first side; at least two contact pads arranged on the first side of the electrically insulating carrier; and a resistive structure on the first side of the electrically insulating carrier, the resistive structure extending from the first contact pad to at least one further contact pad, wherein the resistive structure comprises at least one trimming structure. On the first side of the electrically insulating carrier, the anisotropic conductive material is arranged at least on the trimming structure, either indirectly or directly.

[0059] The sensor element is arranged on the substrate, and the anisotropic conductive material faces the first surface of the substrate. In other words, the sensor element is aligned with the first side of the electrically insulating carrier toward the first surface of the substrate. Through the anisotropic conductive material, a conductive contact is formed between the contact pad of the sensor chip and the conductor structure of the substrate. In particular, the electrical contact is formed locally between the contact pad of the sensor chip and the conductor structure of the substrate. Optionally, the anisotropic conductive material also mechanically fastens the sensor chip to the substrate. In addition, preferably, the anisotropic conductive material provides a higher thermal conductivity than air. At the same time, preferably, the anisotropic conductive material electrically insulates the conductor structure on the first surface of the substrate from the resistive structure of the sensor chip outside the contact pad. According to an embodiment, the anisotropic conductive material can also electrically insulate other components (such as contact patches or conductor structures on the substrate) from each other, so that these other components are not in direct electrical contact with each other.

[0060] Preferably, the electrical contact between the sensor element according to the invention and the conductor structure is made approximately perpendicular to the substrate plane. Particularly preferably, the angle of the current path to the carrier surface is between 75° and 105°, very particularly preferably between 85° and 95°. The anisotropic conductive material parallel to the carrier preferably has an electrically insulating effect.

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

[0062] Preferably, the anisotropic conductive material at least partially or completely covers the at least one trimming structure. Particularly advantageously, the anisotropic conductive material can enclose or even hermetically enclose the at least one trimming structure. In particular, the anisotropic conductive material encloses the trimming location of the at least one trimming structure. Thereby, the at least one trimming structure can be protected from environmental influences, such as oxygen or moisture. Preferably, the anisotropic conductive material in the sensor module partially or completely fills the space between the sensor chip and the substrate.

[0063] Particularly advantageously, the height h1 of the contact pads on the first surface of the sensor chip or of the contact pads in combination with the optional contact patch is higher than the height h2 of the resistor structure. Figure 4a). Alternatively, the conductor structure on the substrate that contacts the sensor chip is higher than the surrounding area of ​​the conductor structure to be contacted. In this way, it can be achieved that the anisotropic conductive material is pressed together in the area between the contact pad and the conductor structure and that electrical contact can be provided locally. In this regard, reference is made to Figure 4 a) and Figure 4 b), which shows this situation by way of example. The area of ​​anisotropic conductive material, to which no increased pressure is applied between the contact pad and the conductor structure during assembly, does not contribute to the electrical contacting of the sensor chip to the substrate in the finished sensor module. Since the anisotropic conductive material covers and protects the at least one trimming structure, there is no need to use an additional insulating layer or cover layer in the area of ​​the at least one trimming structure, as is common in the prior art.

[0064] Preferably, the electrically insulating matrix of the anisotropic conductive material in the sensor module has a higher thermal conductivity than air. Particularly preferably, the thermal conductivity in a direction perpendicular to the substrate is greater than 0.1 W / m·K even outside the dielectric contact. Preferably, the material combination and the bonding process are selected such that the space between the sensor chip and the substrate is completely filled with the anisotropic conductive material. In particular, no gaps are formed at the interface between the anisotropic conductive material and the substrate or the sensor chip. Thus, among other things, the ingress of water, oxygen or other contaminants can be prevented.

[0065] In a preferred embodiment, the sensor element of the sensor module has an anisotropic conductive material to be cured and a flexible sensor chip. The curing of the anisotropic conductive material may cause shrinkage. In addition, the assembly stress caused by shrinkage can be reduced by deforming the flexible sensor chip. In particular, the sensor module has a flexible sensor chip, which is connected to a rigid substrate via an anisotropic conductive material. For example, the rigid substrate can be a metal body, a ceramic part or a glass part.

[0066] In another embodiment, the sensor chip can be arranged on a flexible substrate. In this case, the flexible substrate can compensate for the mechanical stress caused by the shrinkage of the cured anisotropic conductive material by deformation. Thus, the possibility of mechanical tearing can be reduced.

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

[0068] Preferably, the average layer thickness of the anisotropically conductive material is less than 20 μm, particularly preferably less than 10 μm. In particular, only those regions of the anisotropically conductive material are used for determining the average layer thickness, which are not provided with electrical contact.

[0069] Optionally, as described herein, at least one contact patch is arranged on each contact pad. In addition, preferably, at least two spatially separated contact patches can be arranged on the contact pad. In one embodiment, the number of contact patches on the contact pad corresponds at least to the number of conductor structures to be contacted on the substrate. Preferably, the contacting of the conductor structures is carried out via anisotropic conductive material.

[0070] In a particularly preferred embodiment of the present 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 conductor structure on the substrate, respectively. Alternatively, more than two contact patches may also be arranged on one contact pad, wherein a first part of the contact patches contacts a first conductor structure together, and another part of the contact patches contacts a second conductor structure together. In a further alternative, two or more contact patches are arranged on one contact pad and each contact patch contacts a separate conductor structure, respectively.

[0071] In an embodiment where at least two contact patches are arranged on one contact pad and each contact patch contacts a separate conductor structure, preferably a four-wire measurement configuration as known to those skilled in the art in the field of sensor technology can be realized. The advantage of a four-wire measurement configuration is that line resistances and connection resistances do not distort the resistance measurement.

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

[0073] Further optionally, at least two contact patches may be arranged on the contact pad, wherein at least one contact patch has no electrical contact with the conductor structure on the substrate.

[0074] Preferably, in case a plurality of contact patches are present on the contact pad, the contact patches are electrically connected to each other only via the contact pad, wherein there is no direct electrical lead from a contact patch to an adjacent contact patch.

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

[0076] In a third aspect, the present invention relates to a method for manufacturing a sensor module, in particular a sensor module according to the present invention, the method comprising at least the following steps: a) providing a substrate having a first surface, wherein the conductor structure is arranged on the first surface, b) providing a sensor chip, in particular a sensor chip as described herein, c) applying an anisotropic conductive material onto a first side of an electrically insulating carrier of the sensor chip or onto a first surface of a substrate, d) positioning the sensor chip on the substrate such that the resistive structure is oriented towards the substrate and the anisotropic conductive material is present between the sensor chip and the substrate, and e) Establishing an electrically conductive connection between the contact pads of the sensor chip and the conductor structure of the substrate via the anisotropic conductive material.

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

[0078] In particular, during step e), the sensor chip is additionally mechanically fastened to the substrate by means of the anisotropic conductive material.

[0079] For example, the substrate having the first surface on which the conductor structure is arranged may be a circuit board, in particular a printed circuit board (PCB).Preferably, the substrate is an electrically insulating substrate.

[0080] In step b), a sensor chip is provided, in particular a sensor chip as described herein. In particular, the provided sensor chip comprises an electrically insulating carrier, at least two contact pads arranged on a first side of the electrically insulating carrier, and a resistive structure on the first side of the electrically insulating carrier, the resistive structure extending from the first contact pad to at least one further contact pad, wherein the resistive structure comprises at least one trimming structure.

[0081] Features of the components of the sensor chip described herein also apply, where applicable, in particular to the sensor chip of the method according to the invention. Vice versa, this also preferably applies to features of the sensor chip described in the context of the method according to the invention.

[0082] Preferably, the sensor chip in step b) has a nominal resistance. For example, the nominal resistance at 0°C may be 50Ω, 100Ω, 200Ω, 250Ω, 1000Ω, 2500Ω, 5000Ω or 10000Ω. In the case where the resistance of the resistance structure is less than the nominal resistance after the resistance structure is generated, the resistance may be adjusted to the nominal resistance. Preferably, the adjustment to a narrow tolerance range close to the nominal resistance is also referred to as trimming via at least one trimming structure. Preferably, the resistance of the resistance structure (in particular a resistance structure made of platinum) is adjusted within a tolerance range of the nominal resistance according to IEC751 / EN60751 or 1 / 10B class. The trimming of at least one trimming structure may be performed by ablation (e.g., by laser ablation). Optionally, the trimming may be omitted in the case where the resistance of the resistance structure from a previous production step already corresponds to the nominal resistance.

[0083] Preferably, the sensor chip on which the resistor structure is arranged has a positive temperature coefficient of resistance. Particularly preferably, the temperature coefficient of resistance is at least 0.003 K in the range of -50°C to 200°C. -1 , and very particularly preferably at least 0.003 K in the range from 0° C. to 100° C. -1 Preferably, there is a linear relationship between the temperature change and the resistance change.

[0084] In step c), an anisotropic conductive material is applied to the first side of the electrically insulating carrier or to the first surface of the substrate. Preferably, the anisotropic conductive material is applied as a continuous layer or as drops. When the anisotropic conductive material is applied to the first side of the electrically insulating carrier, it is preferably applied so that the contact pad (on which the contact patch is optionally arranged) is covered. In addition, preferably, at least one trimming structure, in particular an existing trimming position, is also covered in this step. In another preferred embodiment, the anisotropic conductive material is applied to the first surface of the substrate, and the conductor structure, in particular at least two conductor structures, are located on the first surface. Preferably, the application of the anisotropic conductive material can be carried out by means of dispensing or printing. Particularly preferably, the anisotropic conductive material is applied to at least two conductor structures on the substrate, which will contact the contact pad or the contact patch arranged on the contact pad. The area between the two conductor structures can also be covered by the anisotropic conductive material. Preferably, the amount of anisotropic conductive material is selected so that the first side of the electrically insulating carrier is covered with an average layer thickness in the range of 1μm-20μm.

[0085] In step d), the sensor chip is positioned on the substrate such that the resistive structure is oriented towards the substrate and the anisotropic conductive material is present between the sensor chip and the substrate. For example, the positioning can be performed using a pick-and-place method. In the pick-and-place method, the sensor chip can be provided, for example, by a tape (e.g., a thermal release tape, a waffle pack, or a gel pack). Optionally, a robot can be used for positioning. Positioning can be performed manually, semi-automatically, or automatically. In an embodiment, positioning can be supported by a microscope.

[0086] In an embodiment, the anisotropic conductive material may at least partially cover at least one trimming structure, and in particular completely hermetically seal at least one trimming structure. For example, the sensor chip may be inserted into the deformable anisotropic conductive material. The deformable anisotropic conductive material may be an adhesive. Optionally, the adhesive may not yet be cured. The sensor chip may be temporarily fixed in the deformable anisotropic conductive material.

[0087] In step e), an electrically conductive connection is established between the contact pad of the sensor chip and the conductor structure of the substrate by means of the anisotropic conductive material. Preferably, the sensor chip is pressed into the anisotropic conductive material so that some of the conductive particles of the anisotropic conductive material respectively establish a local limited electrical contact between the contact pad and the conductor structure. In addition, the anisotropic conductive material can optionally be cured. In particular, curing can be performed if a reactive polymer precursor (e.g. of a polymer resin) is used as a matrix for the anisotropic conductive material. Depending on the polymer precursor used, curing can be induced, for example, by oxygen, moisture, heating or light exposure (e.g. UV light). Curing can increase the strength of the mechanical connection.

[0088] Optionally, steps d) and e) can be performed together. This means that the electrical and mechanical contact is established while the sensor chip is positioned on the anisotropic conductive material. Preferably, the mechanical contact can be full-surface, which means that the first side of the sensor chip is completely covered by the anisotropic conductive material.

[0089] The anisotropic conductive material mechanically fastens the sensor chip to the substrate and at the same time encloses at least one trimming structure on the sensor chip, thereby protecting the at least one trimming structure from environmental influences. The anisotropic conductive material preferably has an electrically insulating effect outside the area where the anisotropic conductive material is pressed together between the contact pad and the conductor structure. Preferably, after step e), the entire space between the sensor chip and the substrate is filled with the anisotropic conductive material. BRIEF DESCRIPTION OF THE DRAWINGS

[0090] The present invention will be described below based on specific embodiments with reference to the accompanying drawings.

[0091] Figure 1 A sensor element according to the prior art is shown.

[0092] Figure 2 A possible method for producing a sensor chip according to the invention is shown.

[0093] Figure 3 A sensor element according to the invention and its arrangement on a substrate are schematically shown.

[0094] Figure 4 A possible embodiment of the method according to the invention for producing a sensor module is shown.

[0095] Figure 5 A possible embodiment of the sensor module according to the invention is shown, in which no insulating layer is arranged on the resistor structure. Reference Mark List

[0096] 1 Sensor chip 2 Sensor element 5 Sensor Module 10 Electrical insulation carrier 11 Dielectric layer 12 Conductive layer 20, 20' contact pad 21, 21' Contact patch 30 Resistor Structure 35 Adjust the structure 36 Adjustment position 40 Anisotropic Conductive Materials 41 Conductive particles 42 Insulation substrate 45 Welding connection 50 Insulation layer 51 Overlay 60 base 70, 70' conductor structure The addition of (x) throughout the text indicates an implementation of the prior art.

[0097] Figure 1A sensor element (2x) of the prior art is shown. Two contact pads (20x, 20'x) are arranged on an electrically insulating carrier (10x). A resistor structure (30x) extends from a first contact pad (20x) to a further contact pad (20'x). The resistor structure (30x) comprises a trimming structure (35x). The trimming structure (35x) is manipulated at a trimming position (36x), for example by means of laser ablation. The resistor 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. A covering layer (51x) is used to cover the entire resistor structure 30x including the trimming structure 35x. The covering layer (51x) can be, for example, a further glass layer.

[0098] A sensor element (2x) of the prior art designed in this way can be fixed to a substrate via contact pads (20x, 20'x), for example by means of welding locations (45x, 45'x). A disadvantage of the prior art is that after trimming and before installation in the sensor module, the trimming structure must be covered with an additional covering layer (51x), in particular a glass layer. 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 adjusted resistance of the resistor structure would also be affected thereby.

[0099] Figure 2A method for producing a sensor chip (1) that can be used for the present invention is described. In step 2a), contact pads (20, 20') are arranged on a first side of an electrically insulating carrier (10). A resistive structure (30) extends from a first contact pad (20) to a further contact pad (20'). The resistive structure (30) comprises a trimming structure (35). Preferably, in this case, the above-mentioned conductive elements (20, 20', 30, 35) are thin-film elements. Preferably, the region of the resistive structure between the dashed lines y and z is designed to be meandering and is primarily responsible for temperature measurement. In step b), an insulating layer (50) is applied to the first side of the electrically insulating carrier (10), for example by spin coating of 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), a contact patch (21, 21') is applied to the contact pad region without the insulating layer. In step e), the resistor structure (30) is trimmed to a nominal resistance via the trimming structure (35). The trimming locations (36) are shown as circular in the figure, which can be generated, for example, with a laser, and the bridging parts of the trimming structure are cut. Optionally, parts of the electrically insulating carrier can also be removed in the region of the trimming locations, or only parts of the trimming structure can be removed. Optionally, the order of steps d) and e) can also be exchanged. The sensor chip (1) obtained by the steps a) to e) shown can be used in a sensor element or a sensor module according to the invention.

[0100] Figure 3An embodiment of a sensor element (2) according to the invention is schematically shown. Contact pads (20, 20') are arranged on an electrically insulating carrier (10), and a resistor structure (30) containing a trimming structure (35) extends between the contact pads (20, 20'). In a 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 position (36). The resistor structure (30) is provided with an insulating layer (50) at least in the area outside the trimming structure (35). The combination of components (10, 20, 30, 35 and 50) without anisotropic conductive material (40) can also be referred to as a sensor chip (1). The anisotropic conductive material (40) is arranged on the sensor chip (1). The anisotropic conductive material (40) comprises conductive particles (42) embedded in an insulating matrix (41). The anisotropic conductive material (40) covers the resistor structure (30) including the trimming structure (35). The trimming structure (35) may have a trimming position (36) which is used to adjust the resistor structure (30) to a nominal resistance. In particular, the trimming structure (35) on which the insulating layer (50) is not arranged is enclosed by the anisotropic conductive material (40) and is therefore protected from environmental influences. The sensor element (2) according to the invention may, for example, be arranged on a first surface of a substrate (60). The conductor structure (70) may be arranged on the first surface of the substrate.

[0101] Figure 4 A possible method for producing a sensor module (2) according to the invention is shown. First, a sensor chip (1) is provided. The sensor chip comprises an electrically insulating carrier (10) on a first side of which contact pads (20, 20') are arranged. A resistor structure (30) extends from a first contact pad to a further contact pad. The resistor structure (30) comprises a trimming structure (35). The resistor 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). On the substrate (60), an anisotropic conductive material (40) (for example, in the form of a layer, in particular in the form of an anisotropic conductive adhesive layer known in the prior art) is arranged in the region of two adjacent conductor structures to be contacted.

[0102] The sensor chip (1) is positioned above a substrate (60) so that a first side of the electrically insulating carrier, on which the contact pads (20, 20') are arranged, faces the substrate (60). Subsequently, the sensor chip (1) is arranged on the anisotropic conductive material (40). Here, the trimming structure (35) is enclosed by the anisotropic conductive material (40). At the same time or subsequently, the anisotropic conductive material (40) is pressed together between the contact pads (20, 20') and the conductor structure (70, 70'), for example using a heated punch. The conductive particles (41) in the anisotropic conductive material (40) establish local electrical contact in the gap between the conductor structure (70, 70') and the contact pads (20, 20'). In the case where the anisotropic conductive material (40) contains a polymer precursor, the anisotropic conductive material can be cured. The height h1 represents the total height of the contact pads, on which the contact patches (21, 21') are optionally arranged. The height h2 represents the height of the resistor structure. It can be seen that h1 is greater than h2. Therefore, pressure can be applied locally to the anisotropic conductive material in the region of the contact pad.

[0103] Figure 5 Shows something like Figure 4 b) sensor element, the difference is that Figure 5 The sensor module does not have an insulating layer (50). In this design, the anisotropic conductive material (40) directly covers the resistor structure (30) and the trimming structure (35) having the trimming position (36).

Claims

1. A sensor element (2), comprising a sensor chip (1) and an anisotropic conductive material (40), wherein the sensor chip (1) comprises: a. an electrically insulating carrier (10) having a first side and a second side opposite to the first side, b. at least two contact pads (20, 20'), said at least two contact pads being arranged on said first side of said electrically insulating carrier (10), and c. a resistor structure (30) on the first side of the electrically insulating carrier (10), the resistor structure (30) extending from a first contact pad (20) to at least one further contact pad (20'), wherein: The resistance structure comprises at least one trimming structure (35), It is characterized in that On the first side of the electrically insulating carrier (10), the anisotropic conductive material (40) is arranged at least on the at least one trimming structure (35).

2. The sensor element according to claim 1, wherein: The resistor structure (30) is at least partially or completely covered by an insulating layer (50) at least in a region outside the at least one trimming structure (35).

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

4. The sensor element according to any one of claims 1 to 3, wherein: The insulating layer (50) comprises a dielectric material selected from the group consisting of: polymer, glass, ceramic and glass ceramic.

5. The sensor element according to any one of claims 1 to 4, wherein: The surface of the resistor 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 contains an oxide, a nitride or an oxide-nitride composite material.

6. The sensor element according to any one of claims 1 to 5, wherein: The anisotropic conductive material (40) is selected from the group consisting of anisotropic conductive two-component adhesive, anisotropic conductive one-component adhesive, anisotropic conductive hot melt adhesive and anisotropic conductive film, and wherein the anisotropic conductive material contains deformable or non-deformable conductive particles.

7. The sensor element according to any one of claims 1 to 6, wherein: The at least one trimming structure (35) of the resistor structure (30) has at least one region in which a portion of the at least one trimming structure (35) is cut away, or in which a material is partially removed.

8. The sensor element according to any one of claims 1 to 7, wherein: The at least one trimming structure (35) covered by the anisotropic conductive material (40) is at least partially uncovered by at least one further passivation layer or cover layer.

9. The sensor element according to any 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 thickness of 0.01 mm 2 or smaller, and / or the distance between two directly adjacent patches on the contact pad is a maximum of 300µm from edge to edge.

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

11. The sensor element according to any one of claims 1 to 10, wherein: The first side of the sensor chip has a maximum width of 1 mm 2 area and / or the sensor chip has a thickness of at most 200 µm.

12. A sensor module (5), comprising: a. The sensor element (2) according to any one of claims 1 to 11, comprising a sensor chip (1) and an anisotropic conductive material (40), b. a substrate (60) having a first surface on which at least two conductor structures (70, 70') are arranged, in, The sensor element (2) is arranged on the substrate (60), and the anisotropic conductive material (40) faces a first surface of the substrate (60). It is characterized in that An electrically conductive connection is formed between the contact pads (20, 20') of the sensor chip and the conductor structures (70, 70') of the substrate (60) via the anisotropic conductive material (40).

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

14. The sensor module according to any one of claims 12 or 13, wherein: In the region between the contact pads (20, 20'), there are no structures which are higher than the combined height of the conductor structure (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 a sensor module according to any one of claims 12 to 14, the method comprising at least the following steps: f) providing a substrate (60) having a first surface, wherein a conductor structure (70) is arranged on the first surface, g) providing a sensor chip (1) according to any one of claims 1 to 11, h) applying an anisotropic conductive material (40) onto a first side of the electrically insulating carrier (10) of the sensor chip (1) or onto the first surface of the substrate (60), i) positioning the sensor chip (1) on the substrate (60) such that the resistive structure (30) is oriented towards the substrate and the anisotropic conductive material (40) is present between the sensor chip (1) and the substrate (60), and j) establishing an electrically conductive connection between the contact pads (20, 20') of the sensor chip and the conductor structures (70, 70') of the substrate (60) via the anisotropic conductive material (40).

16. The method according to claim 15, wherein: The anisotropic conductive material (40) at least partially or completely encloses the at least one trimming structure (35).

17. The method according to any one of claims 15 or 16, wherein: In step b), the sensor chip has a trimming location (36) in the region of the at least one trimming structure (35).

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