Sensor and sensor arrangement

Abstract

The invention relates to a sensor (10), comprising: - a substrate (12) of an electronic device, - at least one bonding pad (14), - at least one bonding layer (16), the bonding pad (14) being arranged between the substrate (12) and the bonding layer (16), and a connecting region (20) for connecting a supply element (52) being provided on a first side (18) of the bonding layer (16), and a contact region (24) being provided on a second side (22) of the bonding layer (16) opposite the first side (18), and - at least one blocking line (26), the blocking line (26) being arranged between the bonding pad (14) and the bonding layer (16), and at least one opening region (28) of a functional structure (30) on the bonding pad (14) being covered by the blocking line (26).

Description

[0001] December 18, 2025

[0002] Yageo Nexensos GmbH M / NEXE-080-PC

[0003] Sensor and sensor arrangement

[0004] Description

[0005] The invention relates to a sensor, in particular a temperature sensor, according to claim 1 or 2, and to a sensor arrangement according to claim 22.

[0006] Sensors are already known from the prior art that have a substrate and a bond pad in a thin-film design and a bond layer.

[0007] German patent DE 10 2011 103 827 B4 describes a temperature sensor that is soldered onto copper conductor tracks via contact fields to construct a heat flow meter. The contact fields are created by internally structuring the thin-film platinum contact fields. A thick-film metal paste with an oxide component is then applied and, during firing, anchored in the freely accessible oxide surface areas of the ceramic plate by the internal structure of the contact fields.

[0008] German patent DE 20 2018 006 504 Ul describes a wire bonding arrangement with a thin-film bond pad made of platinum and a plurality of openings, a bond layer made of a preferably silver-rich, but also oxide-containing paste, which is applied over the same thin-film pad area using thick-film printing. A bonded conductor is then placed on top of this.

[0009] German patent DE 20 2020 101 197 Ul describes a sensor with contact surfaces prepared for sintering with leads in the form of ribbons or stamped parts. The sintering paste required for the joining process can be pre-applied both to the leads and to the contact surfaces.

[0010] A problem with sensors known from the prior art is that the adhesion and, consequently, the electronic connection of the bond wire or a sintered lead are very susceptible to manufacturing-related defects. M / NEXE-080-PC

[0011] 2

[0012] Deviations in the position of the bond wire or the lead wire are a cause of problems. Even a slight deviation in the bond wire's position can lead to the bond wire and the connection breaking more easily.

[0013] Sensor areas with metal-ceramic connections are particularly susceptible to failure before or during the installation of a connecting wire, especially if they are not covered by glass. This also applies if the sensor areas are not yet covered with potting compound.

[0014] The invention is based on the objective of providing a sensor, in particular a temperature sensor, that compensates for the positioning of the electrical lead element, especially a bond wire, on the sensor and improves its adhesive properties. A further aspect is the stabilization of the bond pad's adhesive properties over the period between the sensor's completion and the establishment of the mechanical and electrical connection to the lead.

[0015] Another objective of the invention is to suppress the so-called poisoning of the functional structure. In such poisoning, metal atoms from the bond layer alloy into the bond pad, whereby these metal atoms diffuse further into the functional layer and alter its resistance.

[0016] At the same time, the invention aims to provide a sensor arrangement whose lead wire has optimized adhesion to the contact surface.

[0017] According to the invention, the aforementioned problems are solved by a sensor according to claim 1 or claim 2, and a sensor arrangement according to claim 22.

[0018] A first aspect of the invention relates to a sensor comprising a substrate of an electronic device, at least one bond pad, which can also be called a thin-film pad, and at least one bond layer, which can also be called a thick-film or contact pad.

[0019] The bond pad is positioned between the substrate and the bond layer.

[0020] On one side of the bond layer, a connection area is provided for connecting a supply element, and on one of the first sides M / NEXE-080-PC

[0021] A contact area is provided on the opposite second side of the bond layer. The invention also provides at least one barrier line. The barrier line is arranged between the bond pad and the bond layer. At least one entry point of a functional structure on the bond pad is covered by the barrier line. In particular, at least one entry point of a functional structure on and / or to the bond pad is covered by the barrier line.

[0022] In the following, the statements "essentially perpendicular," "essentially orthogonal," or "essentially from direction x" always refer to spatial directions. Unless otherwise specified, deviations of + / - 30°, and preferably + / - 15°, are to be included in addition to the precisely stated principal direction.

[0023] The lead element can be a bond wire, a ribbon, a stranded wire, a sintered ribbon, a sintered stranded wire, a metallic foil, or a stamped part. Alternatively, the lead element can be a flexible polymer film with at least one printed conductor track. The polymer film can carry two or more printed conductor tracks and contact at least one bond pad with at least one conductor track. In one possible embodiment, a polymer film can carry two conductor tracks, with each conductor track contacting a bond pad. A three- or four-wire configuration is also possible.

[0024] In a special embodiment of the invention, conformal potting of the assembly can take place after the at least one supply element has been attached.

[0025] The bonding layer can be a temperature-stable thick film that has already been dried and fully sintered and / or baked on by thermal treatment. The main component of the bonding layer is preferably metal or at least a metal alloy. A further possible additional component is at least one oxide additive. Additionally, as a second sub-layer, or alternatively, it can be a sintering paste that has simply been pre-applied or dried at a moderate temperature and is prepared for the subsequent build-up process. The sintering paste can contain copper, silver, gold, and / or other precious metals as its main metals. M / NEXE-080-PC

[0026] 4

[0027] Furthermore, it is conceivable that the bond layer is not, or preferably only partially, applied directly or pre-applied to the sensor, but that the bond layer is at least partially arranged on the lead element in order to be connected to the sensor in a further assembly and connection process during the manufacture of the sensor assembly.

[0028] Furthermore, it is conceivable that the bond layer consists of at least two individual layers that were applied sequentially. These individual layers can differ with respect to their main metallic component, alloy composition, the proportion of non-metallic and / or oxide components, and / or the degree of sintering. If at least two individual layers are present as components of the bond layer, they do not necessarily remain sharply separated from one another, but can diffuse and mix into each other globally across the entire interface through sintering and locally through build-up and joining techniques.

[0029] In a particular embodiment, the bonding layer is produced in at least two sublayers that differ in their metal compositions. At least one sublayer is produced by a deposition step using pastes containing metal particles. In a preferred embodiment, at least the portion of the bonding layer that is directly bonded to the bonding pad has oxide components in its alloy composition.

[0030] In a specific embodiment, the bond layer exhibits a gradient in the metal composition and / or the proportion of oxides per volume in the direction perpendicular to the substrate surface. This embodiment is not necessarily limited to the formation of the bond layer in at least two deposition processes. Preferably, the ratio of the volume of oxides to the reference volume (of metal alloy and oxides) is higher in the lower (substrate-closer) third of the bond layer than in the upper (substrate-distant) third. The relative difference in these ratios is preferably > 10%, more preferably > 20%, and particularly preferably > 40%. This applies especially to areas where the bond layer is in direct contact with the substrate. This also applies to areas where the bond layer is in direct contact with the barrier line. M / NEXE-080-PC

[0031] 5

[0032] In one possible embodiment of the invention, the bond layer is formed from a baked-on metal paste comprising oxide particles, in particular crystalline particles and / or glass frit and / or vitrified particles, wherein the metal paste was applied in a structured manner, in particular by means of a screen printing process, stencil printing process or pad printing process.

[0033] The oxide component of at least one bond pad may comprise a mineral, crystalline component and / or glass frit and / or vitrified particles or mixtures thereof.

[0034] In a preferred embodiment of the bonding layer, the oxide content in the bonding layer is 2 wt.% to 14 wt.% based on the platinum content in the bonding pad. In this embodiment, the oxide in the bonding pad is preferably in the form of a glass.

[0035] In a specific embodiment of the bonding layer, the oxide content in the bonding layer is 5 wt.% to 11 wt.% based on the platinum content in the bonding pad. In this embodiment, the oxide is preferably in the form of a glass.

[0036] In another preferred embodiment of the bonding layer, the oxide mineral fine-crystalline content in the bonding layer is 0.05 wt.% to 3.0 wt.% based on the weight of the silver in the bonding pad.

[0037] In a preferred embodiment, the bonding layer comprises platinum, silver, vitrified oxide particles and mineral fine-crystalline particles.

[0038] The barrier line can be arranged between the at least one bond pad and the at least one bond layer in such a way that it only acts as a separating layer and / or diffusion protection layer between the bond pad and the bond layer in sections.

[0039] In one embodiment of the invention, the at least one bond pad is formed from a substantially silver-free platinum alloy and / or the at least one bond layer comprises an alloy containing platinum and silver with a silver concentration of at least 10 wt.% based on the total metal content of the alloy. M / NEXE-080-PC

[0040] 6

[0041] In a common embodiment, at least one of the outer edges of the bond pad remains predominantly (over more than 50% of its length) free of barrier line elements. Alternatively or simultaneously, at least 20% of the bond pad's surface remains free, even though all outer edges are predominantly covered by the barrier line. In this area, the oxide-containing bond layer can preferably make electrical contact with the bond pad and even extend beyond it to be directly fused or sintered onto the substrate.

[0042] In a common design, the substrate is electrically insulating and solid. Preferably, the substrate has no metallic conductive passages. In other words, the substrate preferably has no vias. The substrate can be cuboid or parallelepiped.

[0043] Preferably, the substrate has six outer surfaces. The first and second surfaces of the substrate are the largest in area. The remaining surfaces are smaller in area and are referred to here as cut surfaces. The cut surfaces are predominantly unmetallized. In particular, no electrically conductive connections are formed between the first and second surfaces of the substrate via the cut surfaces.

[0044] The insulation gap between the conductive objects on the first and second sides of the substrate is at least 0.3 mm air, preferably 0.5 mm air; corresponding to a dielectric strength of at least 170 V at room temperature. In special cases, the insulation gap is 1 mm air; corresponding to a dielectric strength of 350 V at room temperature. An increased insulation gap, greater than the height of the substrate, is preferably achieved by edge clearance of the exposed metallic structures (edge-cleared sensors). Preferably, this edge clearance is on the first side of the substrate. If metallization is present on the second side of the substrate, it can optionally be spaced away from the cut surfaces of the substrate.

[0045] In one possible embodiment, the distance between the first and second sides of the substrate is 0.05 to 1 mm. After the component is installed and the bond layer is contacted, the dielectric strength can be further increased by conformal potting. M / NEXE-080-PC

[0046] 7

[0047] In a preferred embodiment of the substrate, the surface roughness of the first side of the substrate is Ra < 100 nm. In a particular embodiment of the substrate, the surface roughness of the first side of the substrate is 30 nm to 50 nm.

[0048] In the preferred embodiment, the described design of the bond pad and bond layer eliminates the need for separate roughening of the substrate surface to ensure the required adhesion for the sensor and connection assembly.

[0049] A particular challenge lies in the time span between the completion of the sensor element and the contacting of at least one connecting element onto the bonding layer. A common approach is to first establish a back-side connection to a printed circuit board, for example, by gluing, soldering, or sintering. Inert gases, reducing agents, and / or elevated temperatures are often used before or during the connection process. The sophisticated design of the sensor element contributes to the long-term maintenance of the bond pad's adhesion during these processes and beyond. Similar conditions can also occur during the preparation, as well as during the electrical connection of the sensor to its lead.

[0050] The barrier line preferably prevents diffusion of the bond layer materials into the materials of the functional structure. A functional structure can be configured, for example, as a resistor structure, particularly a meandering resistor structure, or as a wire or multiple wires. The barrier line prevents, for example, variations across a large number of identically manufactured sensor elements and / or changes to the preset resistances and alloy-specific temperature coefficients. This protective effect applies particularly to the absolute resistance values ​​of resistor elements equipped with at least one adjustment structure, which precisely sets the resistance to a target value.

[0051] A blocking line is understood to be, in particular, a section of the sensor which, due to the material from which it is made, has a blocking effect on adjacent components and / or material layers. This blocking effect specifically concerns an M / NEXE-080-PC that is to be prevented.

[0052] 8

[0053] Diffusion of materials from a first component and / or a first material layer into the material of a second component and / or a second material layer. The barrier line can also be referred to as a barrier material section.

[0054] One application for creating a blocking line is sensors with a precise nominal resistance and quality class F 0.6 (2B) or better. Optionally, the blocking line is applied with an adjustment structure before and / or after the precise resistance adjustment.

[0055] It is possible to adjust the resistance using the matching structure before applying the bond layer. The bilateral diffusion-inhibiting effect of the barrier line is particularly advantageous during bond layer application.

[0056] In one possible embodiment of the invention, the barrier layer is located directly within or between regions of metal alloys with different main metals in their composition. The main metal of an alloy is understood to be the metal present in the highest concentration, particularly by weight percent, and most preferably in a concentration exceeding 60 wt.%.

[0057] It is possible that in a bond layer comprising several parallel sublayers, the blocking line is located in several sublayers. It is also possible that the blocking line is located on a first sublayer and in a second sublayer. The blocking line can be spaced from the bond pad within the entire bond layer and may not be in direct contact with it.

[0058] Furthermore, the junction area of ​​the functional structure with the bond pad is particularly vulnerable. Alloy formation in this area can lead to volume changes and local mechanical instabilities in the layer structure. A barrier line significantly reduces the concentration of metal ions that diffuse locally into the functional structure and thus the so-called poisoning.

[0059] The barrier layer can comprise one or more layers, in particular glass and / or aluminum oxide and / or zirconium oxide and / or magnesium oxide. In one embodiment, at least two oxides can be present as mixed crystals and / or in an M / NEXE-080-PC.

[0060] The barrier line consists of nine common glass compositions. Additionally or alternatively, it can also include other oxides, carbonates, and / or nitrides. The barrier line can be applied, for example, by screen printing, pad printing, stencil printing, vapor deposition, inkjet printing, ADM, CVD, or sputtering.

[0061] In other environments, the barrier line may contain or be made of less temperature-resistant materials, such as polymers, silicones, PTFE, resins, or similar substances.

[0062] The barrier line can cover 5-95% of the bond pad area. Preferably, 5-50%, and more preferably 5-30%, of the area is covered. The barrier line thus preferably does not completely prevent mechanical and electrical contact between the bond pad and the bond layer.

[0063] The blocking line can overlap the functional structure completely or partially. This applies particularly to the entry area of ​​the functional structure. In one embodiment, the blocking line overlaps the entry area of ​​the functional structure.

[0064] In addition to the placement of the barrier line on the junction area of ​​the functional structure according to the invention, this can assume various designs with regard to its lateral extent.

[0065] In a first embodiment, the locking line can be formed in one piece or as a continuous unit (per bond pad) and has no holes.

[0066] It is also conceivable that in another embodiment the locking line is continuous, i.e., bond pad, but has holes.

[0067] In another embodiment, the locking line (per bond pad) can be multi-part.

[0068] In the case of an electrically insulating barrier line, it is not necessary for it to maintain a minimum distance from the sensor edge. This also applies to a sensor designed as an edge-free sensor. M / NEXE-080-PC

[0069] 10

[0070] In another embodiment, particularly in space-saving arrangements, the barrier line can extend over areas of at least two adjacent bond pads. This embodiment requires the use of non-conductive material for the barrier line.

[0071] There are also alternative designs regarding the vertical positioning of the blocking line.

[0072] In a first embodiment, the barrier line is applied to the bond pad before the bond layer is applied.

[0073] In another embodiment, the blocking line can be deposited after the bond layer or at least after parts of the bond layer. In this case, the blocking line is not located, or not completely located, between the bond pad and the lower side of the bond layer. The blocking line is then at least partially located within the bond layer.

[0074] Although the barrier line is surrounded by metallic structures on two sides, it is electrically insulating in many cases. In other words, the barrier line is electrically insulating even though it is directly adjacent to metallic structures on at least two sides. Specifically, the metallic structures away from the barrier line are in direct contact, and the interface between the metallic structures is also metallically conductive.

[0075] The barrier line can directly separate areas with significantly different metal alloys in the bond layer. Furthermore, the barrier line can directly separate areas of different alloys in the bond pad and bond layer. The barrier line can directly separate areas of significantly different metal alloys on a local basis, whereby the simply connected areas with precisely these metal alloys directly adjoin each other elsewhere in the component.

[0076] The barrier line provides component protection during sensor manufacturing. However, the barrier line remains virtually unchanged in the finished component and can subsequently serve as renewed diffusion protection during the application of connections to the sensor and / or passively as a mechanically stabilizing element. M / NEXE-080-PC

[0077] 11

[0078] The electrical voltage difference applied externally across the thickness of the barrier line during operation of the sensor is preferably less than 0.1 V, more preferably less than 0.03 V, and particularly preferably 0.01 V.

[0079] In another embodiment, the barrier line can also be arranged at a distance from the interface between the most different alloys in the bond pad.

[0080] The barrier line can be made of glass or glass-ceramic. The barrier line can consist of one layer or several superimposed layers.

[0081] In one possible embodiment of the blocking line, it is between 10 and 100 pm thick, preferably 20 - 60 pm thick.

[0082] It is known that in glass, the diffusion rate of metal ions, especially silver, through the glass volume increases with the electrical conductivity of the glass. This applies both at constant temperature and with different glass compositions, as well as with constant glass composition and increasing temperature. Above the transformation temperature Tg, the electrical conductivity increases disproportionately. Because the electrical properties of glasses are more readily available, the insulation resistance will be used in the following as a measure of the diffusion resistance of a glass.

[0083] Preferably, the insulation resistance of the barrier line is greater than 10 at a temperature of up to 400 °C. 6 Ohm across the thickness of the barrier line. In one possible embodiment, the insulation resistances of the barrier line are greater than 10 in all directions. 6The insulation resistance is measured in ohms at 100 V and 400 °C between any two sides of the barrier line. In particular, the insulation resistance is maintained even in the direction of the layer thickness.

[0084] The glass of the barrier layer has a transformation temperature Tg of over 600 °C, preferably over 650 °C, and particularly preferably over 700 °C. This makes it possible to effectively prevent metal diffusion substantially perpendicular through the barrier layer. In particular, this means that the mass flux due to the diffusion of metal atoms or ions is geometrically greater along the path around the barrier layer than the mass flux of the metal atoms or ions substantially perpendicular through the barrier layer. M / NEXE-080-PC

[0085] 12

[0086] In the case of using an alloy with a silver concentration of more than 10 wt% for the bonding layer, the diffusion flux of the silver atoms through the barrier line up to the junction of the functional structure remains smaller than the diffusion flux directly through the interface between the bonding layer and the bond pad, and from there to the junction of the functional structure, both during sensor fabrication and subsequent operation. In a preferred, mechanically stable and chemically more inert embodiment, the bond pad is completely covered by subsequent layers, leaving no exposed area. The barrier line and the bonding layer, in particular, serve as the covering. The barrier line itself is at least partially covered by the bonding layer.

[0087] A second aspect of the invention relates to a sensor comprising a substrate of an electronic device, at least one bond pad, which can also be referred to as a thin-film pad, and at least one bond layer, which can also be referred to as a thick-film or contact pad. The bond pad is arranged between the substrate and the bond layer. On a first side of the bond layer, a connection area for connecting a lead element is provided, and on a second side of the bond layer opposite the first side, a contact area is provided. Additionally, the bond pad has at least one recess, the at least one recess being located on the second side of the bond layer.

[0088] The sensor of the second aspect can also be designed like the sensor of the first aspect, so that both a barrier line and a recess in the bond pad can be provided. The barrier line penetrates the bond pad in at least one recess. This allows the barrier line to adhere to the substrate, thus increasing the mechanical stability of the component and, in particular, the penetrated area of ​​the bond pad. The barrier line also serves as a diffusion barrier in the entry area of ​​the functional structure against poisoning that could occur during the application, especially during the burn-in, of a bond layer. For example, the barrier line serves as a diffusion barrier for a platinum functional structure against precious metal poisoning originating from a precious metal thick-film pad with a different main element. In the case of the precious metal from which the so-calledIf poisoning is suspected, it can be caused in particular by all precious metals that do not correspond to the material of the functional structure or that occur in a different concentration within an alloy. In particular, M / NEXE-080-PC.

[0089] 13. The bonding layer comprises alloys with silver or gold as major components and / or palladium and / or platinum in concentrations above 0.5 wt%, in particular above 5 wt%, and most preferably above 10 wt%. The functional structure may be a platinum-based alloy.

[0090] In a preferred embodiment, the bonding layer is a thick film or a thick-film pad, and this layer is depositioned by screen printing, stencil printing, or pad printing followed by firing. Especially at elevated temperatures, typically above the sensor's measuring range, diffusion protection of the barrier line becomes important.

[0091] In another preferred embodiment, the at least one bond pad is designed as a thin-film pad. In this case, the diffusion protection of the barrier line is particularly advantageous.

[0092] Typical thicknesses of the bond pad are between 0.2 - 5 pm, preferably 0.5 - 2.5 pm.

[0093] A characteristic feature is that a metal which, on average, does not occur in the functional structure at concentrations exceeding 0.5 wt%, is present in the region above the barrier line at a concentration increased at least fivefold, preferably tenfold, and particularly preferably fiftyfold. It is irrelevant whether the metal in question is applied directly to the barrier line or whether another metallic layer is arranged in between.

[0094] In one embodiment, the bonding layer can be layered, i.e., it consists of two or more individual layers arranged one above the other or overlapping. The interfaces are not necessarily sharp, as alloying can occur there.

[0095] In one variant of this layered embodiment of the bonding layer, the main metallic component of the lowest layer in the bonding layer can be the same as the main component of the bonding pad. In this variant, it is common for the at least one layer above it to contain a different main metallic component.

[0096] The diffusion barrier of the sensor, in the form of the barrier line, ensures that when the individual layers of the sensor are connected or when the M / NEXE-080-PC is connected

[0097] 14

[0098] The connection element to the sensor does not alter, or at least significantly alter, either the trimmed resistance of the functional structure or the temperature coefficient due to any potential alloy formation. Therefore, when manufacturing a sensor assembly that incorporates such a sensor, the accuracy of the sensor assembly during the measurements to be performed can be ensured.

[0099] The recess allows the bonding layer to contact the substrate and simultaneously distributes the force under mechanical stress on the lead element, in particular a bonding wire, ribbon, strand, sintered ribbon, sintered strand, metallic foil, or stamped part. At the same time, the bonding layer can exhibit a slight spring effect even during the bond formation process.

[0100] It is advantageous for the sensor according to the first aspect or the second aspect of the invention if the bond pad has a plurality of recesses.

[0101] It is particularly advantageous for the sensor according to the first aspect or the second aspect of the invention if the bond pad has a mesh structure with a plurality of recesses, so that at least the contact area of ​​the bond layer and the substrate are in contact with each other.

[0102] Additionally or alternatively, the bond pad can have a mesh structure with numerous cutouts, ensuring contact between at least the barrier line and the substrate. The force-optimized contact created by the cutouts, forming a hole pattern, improves adhesion by increasing the adhesive force between the individual contacting layers. This also increases the adhesive force for the subsequent connection of the lead element to the sensor.

[0103] It is particularly advantageous if the cutouts in the network structure are arranged regularly. These cutouts can be recurring, unconnected spaces.

[0104] In a preferred embodiment of the bond pad, the majority of the recesses are enclosed by the metallic structure of the bond pad. In a special M / NEXE-080-PC

[0105] 15

[0106] In this embodiment of the bond pad, all recesses are enclosed by the metallic structure of the bond pad.

[0107] In one embodiment of the bond pad, some or all of the recesses are not completely enclosed by the metallic structure of the bond pad. This embodiment occurs particularly in conjunction with a barrier line that is arranged at least partially over incompletely enclosed recesses.

[0108] In a preferred embodiment of the bond pad with a recess, this recess is completely enclosed by the metallic structure of the bond pad.

[0109] Preferably, the bond pad has several recesses that are penetrated by the locking line.

[0110] In a special embodiment of the bond pad with a recess, the recess is not partially bounded by the metallic structure of the bond pad, but rather borders one or more other recesses. In other words, the recess and the other recess merge seamlessly without any boundary.

[0111] It is possible that the recess adjoins at least one other recess, which in turn is not bounded by the metallic structure of the bond pad at at least one other point. Preferably, this recess is then at least partially covered by the barrier line. Equally preferred is the recess in this case being covered by the barrier line at least in one area facing away from the recess.

[0112] These gaps in the mesh structure mean that the positioning of the connecting element, especially the bonding wire, on the sensor can later be chosen randomly, since the overall adhesion of the connecting element, especially the bonding wire, is increased. Therefore, the accuracy of the position during the connection process, e.g., bonding, of the connecting element does not need to be as precise.

[0113] In this context, "contacted" refers to a mechanical connection between the bond layer and the substrate or the barrier line. M / NEXE-080-PC

[0114] 16

[0115] For the sensor according to the first aspect or the second aspect of the invention, it is further advantageous if the mesh structure is provided at least in a bond area of ​​the bond pad, wherein the bond area corresponds to the contact area of ​​the bond layer and wherein the bond area and the contact area are contacted with each other.

[0116] The bonding area of ​​the bond pad and the contact area of ​​the bond layer can therefore be arranged one above the other, for example, congruently. The mesh structure can thus be adapted to both the bonding area and the contact area. This increases the local flexibility when positioning a lead element. Since the mesh structure does not need to cover the entire surface of the bond pad, the adhesion between the bond layer and the substrate can be further improved locally.

[0117] The contact area and the connection area have the same orientation in their extent. The longitudinal axis of the maximum length of the contact area is therefore parallel or coincident with the longitudinal axis of the maximum length of the connection area.

[0118] The functional structure is a metallic structure used to create an electrical connection or resistance. This functional structure can, for example, be arranged in a meandering pattern and can therefore also be called a meander. The functional structure can act as a measuring resistor. In the case of a temperature sensor, the functional structure is used to measure the temperature.

[0119] The confluence area of ​​the functional structure can, for example, be trumpet-shaped.

[0120] For integration of the sensor into an electronic assembly, the substrate can be fixed to a printed circuit board (PCB), e.g., by sintering, soldering, or gluing, or it can already be sintered, soldered, or glued to the PCB. Prior to the connection process with the PCB, the sensor substrate can be provided with an additional metallization on the back side. This backside metallization is electrically isolated from the frontside bond pads. M / NEXE-080-PC

[0121] 17

[0122] In applications with higher voltage differences, e.g., above 200 V, 300 V, or 500 V, between the surface of the bonding layer and a back-side metallization, edge clearance of the metallic surface coatings, particularly in the area around the pads, may be necessary. This reduces the area available for pad buildup. In this case, concepts for optimizing adhesion properties over a small area are particularly relevant.

[0123] Furthermore, for the compatibility of the sensor with other electronic components on the same circuit board, it can be advantageous if the bonding layer is formed, at least in some areas, from a precious metal paste, particularly a silver paste. The precious metal paste can be applied in a single layer or in multiple layers and, after heat treatment, forms a thick precious metal film. The thickness of the film, particularly a silver film, is preferably greater than 15 pm, more preferably greater than 17 pm, and more preferably 20–30 pm.

[0124] In a different environment, the sinterable layer can also consist of copper, or the bonding layer can be coated with a copper or nickel layer. The layer can then be further processed, for example, using the Die Top Process (DTS®).

[0125] The heat treatment of the silver paste in the contact pad is preferably carried out at temperatures between 500°C and 860°C. Depending on the thickness and composition of the silver sintering paste, the preferred temperature can be below 815°C, preferably below 800°C, more preferably below 700°C, and even more preferably below 500°C. The comparatively low curing temperature and short curing time minimize the diffusion of silver into, for example, platinum, thus reducing silver poisoning.

[0126] It is particularly advantageous to use a sintering paste, especially a silver sintering paste, as the contact pad. This means that the sensor is exposed to lower temperatures during the drying of the sintering paste, and the subsequent connection to the leads can be made using a pressure-assisted sintering process. Furthermore, optimizing the utilization of the available area on the sensor can be advantageously achieved if the connection area of ​​the first side extends along its maximum longitudinal extent (M / NEXE-080-PC).

[0127] 18 has a longitudinal axis. Additionally or alternatively, the contact area of ​​the second side of the bond layer can have a longitudinal axis along its maximum longitudinal extent. The network structure has a principal axis for orienting a plurality of principal lines and a plurality of minor lines. For this purpose: a) the longitudinal axis of the bonding area and the principal axis of the network structure are arranged at an angle of 30° to 60°, preferably substantially at an angle of 40° or 50°, to each other, or b) the longitudinal axis of the bonding area and the principal axis of the network structure are arranged substantially parallel or parallel to each other.

[0128] The multitude of main lines can be arranged parallel to the main axis of the network structure. It is also conceivable that the main lines are arranged at an angle to the main axis. This angle can be greater than or equal to 30°, preferably greater than or equal to 45°, more preferably greater than or equal to 60°, and less than or equal to 90°, more preferably less than or equal to 80°, more preferably less than or equal to 70°.

[0129] The secondary lines are preferably arranged at an angle to the main lines. This angle can be greater than or equal to 30°, preferably greater than or equal to 45°, more preferably greater than or equal to 60°, and less than or equal to 90°, preferably less than or equal to 80°, more preferably less than or equal to 70°.

[0130] These arrangements, or rather the possibilities for arranging the network structure in relation to the bonding area, allow for flexible sensor design. The arrangement can be selected depending on the desired adhesive force, the size of the respective areas, and the expected stress during the bonding process. Simultaneously, these arrangements can positively influence the force distribution when stressing the subsequently applied bonding wire or when forces are applied to the bonding wire.

[0131] In the sensor according to the first aspect or the second aspect of the invention, it is particularly advantageous if the blocking line is at least 3%, M / NEXE-080-PC

[0132] 19 preferably at least 5%, further preferably at least 7% of a bond pad surface is covered.

[0133] In one possible embodiment, the barrier line can extend into the bonding area of ​​the bond layer and partially or completely underlie it. Optionally, the entire bonding area can be underlain by the barrier line.

[0134] The barrier line can then advantageously overlap the bond pad and act as a diffusion barrier. The barrier line can therefore be adapted to the area of ​​the bond pad or the available surface area of ​​the substrate.

[0135] The barrier line contacts the bond layer, partially preferentially from below, and the bond pad from above and from the sides of the recesses, as well as the substrate.

[0136] In a preferred embodiment, the barrier line preferably covers a maximum of 30%, preferably a maximum of 20%, and more preferably a maximum of 15% of the bond pad surface. This ensures that the adhesive area of ​​the bond layer makes mechanical contact with the substrate to guarantee the stability of the sensor.

[0137] This leads to an improved bilateral diffusion barrier between the functional structure and the bond layer.

[0138] In a specific embodiment, the barrier line is located, at least partially, between the adhesive area and the substrate. There, the adhesive area of ​​the bonding layer additionally contacts the barrier line, which in turn provides optimized adhesion via the recesses or notches in the bond pad to improve sensor stability. In this case, the barrier line can cover more than 30%, preferably 30-90%, of the bond pad surface.

[0139] In a further advantageous embodiment of the sensor according to the first or second aspect of the invention, an adhesive area is formed in the contact area of ​​the bond layer, wherein the adhesive area is arranged within a boundary. The boundary preferably has a maximum longitudinal extent with a minimum length of at least 100 pm, M / NEXE-080-PC

[0140] The boundary has a diameter of at least 200 pm and a maximum length of at most 400 µm, preferably at most 300 pm. The boundary preferably has a maximum width of at least 20 µm, preferably at least 50 pm, and a maximum width of at most 100 pm, preferably at most 75 pm. The boundary is positioned at a distance of at least 200 pm from the circumferential edges of the bond pad. In the contacted state, the bonding area is located within the boundary, such that the bonding area at least partially, and in particular completely, covers at least one recess, preferably at least two recesses, and more preferably at least three recesses, of the bond pad's mesh structure, thus contacting the bonding area of ​​the bond layer with the substrate.

[0141] This increases the adhesive strength in the contacted state and ensures that the individual layers—bond pad, bond layer, and substrate—are directly or indirectly connected. Within the defined boundaries, at least sufficient adhesion can always be guaranteed.

[0142] The longitudinal extent of both the boundary and the area of ​​detention is greater than the lateral extent of the boundary or the area of ​​detention.

[0143] Furthermore, it can be advantageous for the sensor if the maximum longitudinal extent of the adhesive area is arranged substantially perpendicular or at right angles to the maximum longitudinal extent of the connection area and thus the contact area. "Substantially perpendicular" here means that a deviation of a maximum of 10°, preferably a maximum of 5°, from a perpendicular arrangement is permissible.

[0144] In a further advantageous embodiment of the sensor, at least a proportion of the multiple recesses of the bond pad's mesh structure are arranged below the blocking line. Alternatively or additionally, at least a proportion of the multiple recesses of the bond pad's mesh structure are arranged below the bond layer.

[0145] This leads to an improved diffusion barrier between the functional structure and the bond layer. At the same time, the required force, which is necessary for the M / NEXE-080-PC, can be reduced.

[0146] 21

[0147] The force exerted by applying or possibly removing the bond wire from the sensor may be increased.

[0148] To maximize the adhesion between the individual layers and, of course, between the bond wire and the sensor, it is conceivable that the numerous recesses in the mesh structure have a medium feature size. This medium feature size corresponds to a maximum of 20%, preferably a maximum of 15%, and more preferably a maximum of 12%, of the maximum longitudinal extent of the bond pad.

[0149] As mentioned above, the network structure contains regular repeating units, the main lines and the secondary lines, which are separated from each other by gaps or voids. The mean structure size indicates an average value for the dimension of these voids. It is a metric that provides an idea of ​​the characteristic size of the structure within the network.

[0150] Furthermore, it can be advantageous for the sensor if the sum of the surface areas of the multitude of recesses of the bond pad corresponds to 20% to 80%, preferably 30% to 70%, more preferably 33% to 60%, of the surface area of ​​the bond pad.

[0151] This also has a positive effect on the adhesion of the bonding wire to the sensor.

[0152] To form at least a sufficient diffusion barrier with optimized adhesive properties of the sensor, it is advantageous if the barrier line has at least one of the following materials:

[0153] - Glass,

[0154] - Glass ceramic and / or

[0155] - Metal oxide, in particular aluminum oxide and / or zirconium dioxide and / or magnesium oxide and / or

[0156] - Metal nitride and / or carbonate

[0157] Furthermore, it is possible that at least one recess of the bond pad has an oval and / or round and / or rectangular shape, at least partially. M / NEXE-080-PC

[0158] 22

[0159] The at least one recess then essentially exhibits one of the aforementioned shapes, meaning that the shape can deviate from the geometric form within certain limits. The shape can therefore be symmetrical or asymmetrical. It is also conceivable that the aforementioned shapes are combined. Accordingly, one section of the shape could be oval and the other rectangular, or something similar.

[0160] The shape of the at least one recess can be determined by the required contact area. Therefore, it can be flexibly adapted to the respective sensor size and the intended size of the contact (e.g., with a connecting element such as a bonding wire, bondable or sinterable ribbon or strand, a metallic foil, or even a stamped part).

[0161] Furthermore, it can be advantageous for the sensor if the area of ​​the recess of the bond pad corresponds to 15% to 60%, preferably 20% to 50%, more preferably 40% to 50%, of the area of ​​the bond pad surface.

[0162] These size ratios allow for both sufficient adhesive properties for contacting the lead element and sufficient contact between the substrate and the bond layer or barrier line.

[0163] These properties can also be achieved if the area of ​​the recess corresponds to at least 90%, preferably at least 100%, further preferably at least 110%, of the area of ​​the connection area for connecting or attaching a bond wire.

[0164] The recess has a longitudinal axis oriented along its maximum extent. This longitudinal axis can be parallel, congruent, or at an angle between 10° and 90° to the longitudinal axis of the bonding or contact area. The recess's position on the bond pad surface is freely selectable; that is, it can be centrally or off-center. M / NEXE-080-PC

[0165] 23

[0166] In one possible embodiment, the shape of the recess is approximately an ellipse with a major axis of 700 pm to 900 pm and a minor axis of 250 pm to 450 pm, or the recess encloses this shape.

[0167] The at least one recess and / or the cutout can be removed from a metal coating by structuring in the same way and using the same process in which the functional structure is also structured.

[0168] Alternatively or additionally, the at least one recess and / or the indentation can be created in the bond pad by laser ablation or mechanical abrasion. In this case, it is possible that the creation of the at least one recess and / or indentation takes place after the resistance has been adjusted.

[0169] Another aspect of the invention relates to a method for manufacturing a sensor according to the invention. In a method for manufacturing a trimmed sensor with a blocking line and a recess in the bond pad, it is possible to perform the following manufacturing steps.a) Optional placement of the blocking line on at least one edge region of the bond pad, covering the entry area of ​​the functional structure into the bond pad; b) Adjustment of the resistance of the functional structure by laser calibration in at least one calibration structure of the sensor; c) Structuring, in particular optional structuring, of the recess and / or cutouts in the bond pad, in particular structuring by laser ablation; d) Covering the calibration structure by applying a dielectric layer, in particular a glass layer; e) Alternative or additional placement of a blocking line on at least one edge region of the bond pad, covering the entry area of ​​the functional structure; M / NEXE-080-PC.

[0170] 24 f) Applying the bonding layer over at least part of the recess formed in step c).

[0171] In a particular embodiment of the procedure, no further adjustment of the resistance of the functional structure takes place after step b). This is made possible by the fact that the existing blocking line prevents the functional structure from being poisoned in step f), and therefore a later and / or second adjustment of the sensor's resistance value is no longer necessary.

[0172] In a particular embodiment of the method, in which the at least one recess is produced by laser ablation, the manufacturing steps are carried out in the sequence specified above, whereby steps a) and / or e) can alternatively be omitted. Additionally, steps b) and c) are carried out sequentially in the specified order. This procedure can eliminate the need to readjust the sensor under the laser apparatus between steps b) and c).

[0173] For both the sensor of the first aspect and the sensor of the second aspect, it can be advantageous if the substrate has a ceramic material, in particular aluminium oxide or zirconium oxide.

[0174] The bond pad may contain platinum. The bond pad may be made of the same material as the functional structure.

[0175] Furthermore, the supply element, in particular the bond wire, may contain aluminium and / or copper or be designed as a sheath wire made of these materials.

[0176] Alternatively, the lead element can consist of a metal ribbon, a metallic foil, a stranded wire, or a stamped part that is sintered with the bonding layer. The lead elements can be made of, for example, copper, nickel, gold-plated nickel, or aluminum alloys.

[0177] It is also possible that the lead element, in particular the bond wire, comprises copper and is coated with a precious metal or with titanium (Ti), nickel (Ni), or chromium (Cr). Alternatively, the lead element, in particular M / NEXE-080-PC

[0178] 25 the bond wire shall comprise an aluminium material and be coated with an alloy, in particular an aluminium-silicon (AlSi) alloy.

[0179] Furthermore, it can be advantageous for the adhesion and conductivity properties and the strength of the sensors if the bonding layer contains an adhesion promoter and at least one of the following precious metal components:

[0180] - Silver (Ag),

[0181] - Silver-Platinum (AgPt),

[0182] - Silver Palladium (AgPd) or

[0183] - Gold (Au).

[0184] This is particularly advantageous if the bond layer

[0185] - 80 to 99.5 percent by weight of silver material and 0.5 to 20 percent by weight of platinum material or

[0186] - 60 to 95 percent by weight of silver material and 5 to 40 percent by weight of palladium material and / or platinum content, each in relation to the total mass of the precious metal components. In the case of a bond pad constructed from multiple layers, these specifications apply only to the uppermost (most distant) layer.

[0187] A third aspect of the invention relates to a sensor arrangement comprising a sensor according to a first and / or second aspect of the invention and a connecting element for establishing an electrical connection with the sensor. The connecting element is connected to the sensor via the connection area of ​​the first side of the bond layer.

[0188] By incorporating a locking line and / or a recess into the sensor design, the adhesion of the bond wire in the connection area is optimized by increasing the permissible deviation of the bond wire's position on the bond pad. Therefore, absolute positional accuracy is not required to ensure proper function of the bond wire with the sensor.

[0189] Instead of the bond wire, a ribbon, a soldered wire, a stranded wire, or a stamped part can also be used. M / NEXE-080-PC

[0190] 26

[0191] In the electrically contacted, and in particular bonded, state, the length of the bonding area is stressed on one side. This stressed side of the bond can be any side at the edge of the bond in the wire direction, wherein the stressed side is a maximum of 2%, preferably a maximum of 4%, more preferably a maximum of 7%, and more preferably a maximum of 10%, of the structural length of the hole pattern of the recesses.

[0192] Further features and advantages of the invention will become apparent from the following description, in which preferred embodiments of the invention are explained with reference to schematic drawings.

[0193] This shows:

[0194] Figures a-li show cross-sections through the pad of a sensor with different embodiments aa to i of the locking line on the bond pad;

[0195] Figure 2 schematic representation of a sensor according to a first embodiment with a blocking line;

[0196] Figure 3 schematic representation of a sensor according to a second embodiment with a recess;

[0197] Figure 4 Top view of a bond pad in a schematic representation;

[0198] Figure 5a Top view of a bond pad for the first embodiment according to

[0199] Fig. 2;

[0200] Figure 5b Top view of a bond pad in an alternative embodiment and a locking row in an alternative embodiment;

[0201] Figure 5c Top view of a bond pad and a locking line in further alternative embodiments;

[0202] Figure 6 Top view of a bond layer for the first embodiment according to Fig. 2; M / NEXE-080-PC

[0203] 27

[0204] Figure 7 schematic representation of an arrangement of an adhesive area on a bonding layer or bonding pad; and

[0205] Figure 8 shows a sensor arrangement.

[0206] Figures 1a to 1li show a cross-section through various embodiments of a sensor 10 according to the invention. Figures 1a to 1li each show the sensor 10 with a substrate 12 of an electronic device, at least one bond pad 14, and at least one bond layer 16. The bond pad 14 is arranged between the substrate 12 and the bond layer 16. A barrier line 26 is also provided. Furthermore, the bond pad 14 has a mesh structure 32 with a plurality of regular recesses 34.

[0207] Figures 1a to 1li show the sensors 10 after completion of the manufacturing process. To clarify the relationships between the individual components and layers, particularly with regard to the exploded views in Figures 2 and 3, the outer edges of the bond pad 14, some of which are not in the section plane, are additionally shown with dashed lines in Figures 1a to 1li. After manufacturing the sensors, the areas of the mesh structure 32 not filled with the material of the bond layer 16 are primarily visible in the cross-section of the bond pad 14. The recesses 34 are filled with material of the bond layer 16, as can be seen from the hatching. The same applies to the area with the barrier line 26; here, too, the recesses 34 of the mesh structure are filled with the material of the barrier line 26, as can be seen from the hatching.

[0208] Fig. 1a shows a sensor 10 with its bond pad 14, which has a recess 40 (shown here with dashed lines) that is clearly visible, especially before the application of the bond layer 16 (compare Figures 2 and 3). The at least one recess 40 is associated with the second side 22 of the bond layer 16, particularly before the application of the bond layer 16. After the bond layer 16 or barrier line 26 is applied to the bond pad 14, the recesses 34 and the recess 40 are filled with the material of the bond layer 16, and the bond layer 16 is in contact with the substrate 12 at these points, as can be seen from the hatching. The barrier line 26 contacts both the bond pad 14 and the substrate 12 and extends over approximately 20% of the area M / NEXE-080-PC.

[0209] 28 of the bond pad 14. In this covered area, the material of the barrier line 26 is also present in the recesses 34 of the mesh structure.

[0210] Fig. 1b shows a sensor 10 with a continuous mesh structure 32. The barrier line 26 contacts both the bond pad 14 and the substrate 12 and extends over approximately 20% of the area of ​​the bond pad 14. In this covered area, the material of the barrier line 26 is also present in the recesses 34 of the mesh structure 32.

[0211] Fig. lc shows a sensor 10 with a continuous mesh structure 32. The barrier line 26 contacts both the bond pad 14 and the substrate 12 and extends over approximately 90% of the area of ​​the bond pad 14. In this covered area, the material of the barrier line 26 is also present in the recesses 34 of the mesh structure 32. The very large barrier line 26 completely covers the connection area 20.

[0212] Fig. 1d shows a sensor 10 with a continuous mesh structure 32. The barrier line 26 contacts both the bond pad 14 and the substrate 12 and is formed in sections, here in two sections. A first barrier line section 26a covers approximately 40% and a second barrier line section 26b approximately 20% of the area of ​​the bond pad 16. In this covered area, the material of the barrier line 26 is also present in the recesses 34 of the mesh structure 32. This design of the barrier line 26 can also be used in a sensor 10 with a recess 40. The sensor 10 according to Fig. 1e corresponds in its structure to the sensor 10 of Fig. 1a, however, the bond layer 16 has three distinguishable bond layer sub-layers 16a, 16b, 16c. It is also conceivable that the bond layer 16 is composed of two distinguishable bond layer single layers 16a, 16b or even has more than three bond layer single layers.

[0213] Fig. 11 shows another sensor 10, the structure of which corresponds to that of Fig. 1a. However, here the barrier line 26 has a different height. Accordingly, there is a gap between the mesh structure 32 and the barrier line 26, which is filled with the material of the bond layer 16. The recesses 34 are nevertheless partially filled with the material of the barrier line 26. M / NEXE-080-PC

[0214] 29

[0215] Fig. lg shows a sensor 10 with a barrier line 26 as in Fig. lf. However, here the bond layer 16 has two bond layer sublayers 16a, 16b. The barrier line 26 is applied to the bond layer sublayer 16a, which covers the bond pad 14, and contacts the substrate 12 via several recesses 34 without covering the mesh structure 32.

[0216] Fig. lh shows a sensor 10 with a barrier line of alternative height. The bond layer 16 has two bond layer sublayers 16a and 16b. The barrier line 26 is applied to the bond layer sublayer 16a, which covers the bond pad 14, and contacts the substrate 12 via a recess 34 without covering the mesh structure 32. In this case, the recess of the bond layer is located at the edge of the bond layer and is only bounded on one side by the metal of the bond pad. The barrier line 26 covers approximately 20% of the area of ​​the bond pad 14 without making contact over its entire surface.

[0217] Figure 11 also shows a sensor 10 with two bond layer sublayers 16a, 16b of the bond layer 16. The barrier line 26 is arranged in both bond layer sublayers 16a, 16b. Here too, contact with the substrate 12 is formed. Similar to Figure 12h, approximately 20% of the area of ​​the bond pad 16 is covered by the barrier line 26, without the barrier line 26 contacting the bond pad 16 over its entire area.

[0218] Figures 2 and 3 each show a sensor 10 with a substrate 12 of an electronic device, at least one bond pad 14, and at least one bond layer 16. The bond pad 14 is arranged between the substrate 12 and the bond layer 16. Additionally, a connection area 20 for connecting a lead element 52 is provided on a first side 18 of the bond layer 16, and a contact area 24 is provided on a second side 22 of the bond layer 16 opposite the first side 18. In the illustrated embodiment, the bond pad 14 has at least one recess 40, which is located on the second side 22 of the bond layer 16. The recess 40 has an oval shape. In an embodiment not shown, the recess 40 can also be round or rectangular.

[0219] Additionally, the first embodiment according to Fig. 2 provides a locking line 26. The locking line 26 is located between the bond pad 14 and the bond layer 16 M / NEXE-080-PC

[0220] 30 arranged and covers at least one junction area 28 of a functional structure 30 on the bond pad 14.

[0221] In an embodiment not shown here, the sensor can have a locking line 26 without providing a recess 40.

[0222] In both the embodiment according to Fig. 2 and according to Fig. 3, the bond pad 14 has a mesh structure 32 with a plurality of regular recesses 34, so that at least the contact area 24 of the bond layer 16 and the substrate 12 are in contact with each other.

[0223] In the embodiment according to Fig. 2 with the barrier line 26, at least a portion of the recesses 34 is covered by the barrier line 26, so that at least the barrier line 26 and the substrate 12 are in contact with each other.

[0224] Fig. 4 shows the bond pad 14 with a recess 40 and the entry area 28 of the functional structure 30. In contrast to the embodiments shown in Figs. 2 and 3, the plurality of recesses 34 are arranged irregularly here.

[0225] Fig. 5a shows the structure of Fig. 4 with an additional locking line 26.

[0226] Fig. 5b shows an alternative structure of the bond pad 14 with a plurality of recesses 34 and an alternative design of the locking line 26.

[0227] Fig. 5c shows another alternative construction of the bond pad, which in this case has no recess and no cutouts and a simple form of the locking line 26.

[0228] Fig. 6 shows a top view of a sensor 10, which is configured either according to Fig. 2 or according to Fig. 5a. It can be seen that the connection area 20 and the recess 40 are essentially congruent. This arrangement also applies to sensors 10 without a locking line 26.

[0229] In the embodiments shown in Figs. 2 and 3, the mesh structure 32 is provided at least in one bonding area 36 of the bond pad 14. The bonding area 36 M / NEXE-080-PC

[0230] 31 not only corresponds essentially in its extent and orientation to the contact area 24 of the bond layer 16, but is also in contact with it.

[0231] Both the connection area 20 of the first side 18 and the contact area 24 of the second side 22 of the bond layer 16 have a longitudinal axis xB along the maximum longitudinal extent Lvb of the connection area 16. In addition, the network structure 32 has a principal axis HA for the orientation of a multitude of principal lines HL and a multitude of minor lines NL.

[0232] The longitudinal axis xB of the connection area 20 and the main axis HA of the network structure 32 can be arranged at an angle o of 30° to 60°, preferably substantially at an angle o of 40° or 50°, to each other.

[0233] In the embodiments according to Figs. 2 and 3, the longitudinal axis xB of the connection area 20 and the main axis HA of the network structure 32 are arranged substantially parallel or parallel to each other. In this case, the main lines HL are arranged at an angle θ of 30° to 60°, preferably substantially at an angle θ of 40° or 50°, to each other. The secondary lines NL are arranged substantially orthogonal to the main lines HL. However, this angle can also be between 30° and 90°.

[0234] The barrier line 26 shown in Fig. 2 only partially covers the bond pad 14 or one side 42 of the bond pad 14 facing the bond layer 16. An overlap of at least 3% of the bond pad 42 may already be sufficient to provide an adequate diffusion barrier.

[0235] In both the first and second embodiments, an adhesion area 38 is formed in the contact area 24 of the bond layer 16, wherein the adhesion area 38 is arranged within a boundary 41, as shown in Fig. 7. The boundary 41 has a maximum longitudinal extent La with a minimum length of at least 100 pm, preferably at least 200 pm, and a maximum length of at most 400 pm, preferably at most 300 pm, and a maximum width Ba with a minimum width of at least 20 pm, preferably at least 50 pm, and a maximum width of at most 100 pm, preferably at most 75 pm. M / NEXE-080-PC

[0236] 32

[0237] To ensure that the bonding area 38 adheres sufficiently after contact, the boundary 41 is arranged at a distance D of at least 200 pm to the circumferential edges 39 of the bond pad 14 and / or the bond layer 16.

[0238] In the contacted state, the adhesive area 38 is arranged within the boundary 41 and at least partially covers at least three recesses 34 of the mesh structure 32 of the bond pad 14, so that the adhesive area 38 is in contact with the substrate 12.

[0239] The bonding area 38, as shown in Fig. 7, can be significantly smaller than the boundary 41; however, as long as it lies within the boundary 41, adhesion is ensured. It is also possible for the bonding area 38 to be the same size as the boundary 41 and to completely cover the network structure 32.

[0240] The adhesive area 38 can have a rectangular shape, as shown in Fig. 7, or be a part of the connection area 20, as shown in Figs. 2 and 3.

[0241] The maximum longitudinal extent Lhb of the adhesion area 38 is arranged perpendicular to the longitudinal extent Lvb of the connection area 20. The maximum longitudinal extent Lhb of the adhesion area 38 corresponds to the extent of the longest edge of the circumferential edges of the adhesion area 38, see Fig. 7.

[0242] As shown in Figures 2, 5a and 5b, at least a proportion of the plurality of recesses 34 of the mesh structure 32 of the bond pad 14 is arranged below the barrier line 26 and below the bond layer 16. Figure 3 shows that a proportion of the plurality of recesses 34 of the mesh structure 32 of the bond pad 14 is arranged below the bond layer 16.

[0243] The numerous recesses 34 of the mesh structure 32 have a mean structure size, where the mean structure size corresponds to a maximum of 20% of the maximum longitudinal extent L of the bond pad 14. The maximum longitudinal extent L of the bond pad is aligned parallel to the longitudinal axis xB.

[0244] In the illustrated embodiments, the sum of the surface areas of the multitude of recesses 34 of the bond pad 14 corresponds to 33% to 60% of the M / NEXE-080-PC.

[0245] 33

[0246] The area of ​​the side 42 of the bond pad 14 facing the bond layer 16. The sum of the areas can also correspond to between 20% and 80% of the area of ​​the side 42 of the bond pad 14 facing the bond layer 16. Whereas the area of ​​the at least one recess 40 of the bond pad 14 corresponds to between 25% and 30% of the area of ​​the side 42 of the bond pad 14 facing the bond layer 16.

[0247] For a well-functioning diffusion barrier, barrier line 26 comprises glass, glass-ceramic and / or metal oxide and / or nitrides and / or carbonates as materials. The metal oxide of barrier line 26 in Fig. 1 is aluminum oxide, and that of Figs. 5 and 6 contains calcium oxide, bismuth oxide, and boron oxide.

[0248] Fig. 8 schematically shows a sensor arrangement 50 comprising a sensor 10 according to one of the embodiments described above in Figs. 2 to 5, and a connecting element 52 for establishing an electrical connection with the sensor 10. The connecting element 52 is connected to the substrate of the sensor 10 via the connection area 20 of the first side 18 of the bond layer 16.

[0249] Specific embodiments for the manufacture of a sensor arrangement 50, for example a sensor arrangement 50 according to Fig. 8, with test results:

[0250] Example 1:

[0251] First, the sensors 10 are manufactured as follows:

[0252] On one upper surface, the cuboid substrate 12 made of aluminum oxide is coated with a thin layer of platinum. The substrate is sufficiently large to accommodate a large number of sensors side by side. This platinum layer is approximately 1 pm thick and is applied by physical vapor deposition (PVD). The meandering functional structure 30, alignment structures, and two bond pads 14 are patterned from the continuous metal layer by photolithography. The functional structure 30 of the component has a nominal resistance of 1000 ohms, achieving a quality class F 0.6 (2B). M / NEXE-080-PC

[0253] 34

[0254] The grid structure 32 of the bond pads 14 is a lattice pattern and features main lines HL and secondary lines NL. These main lines HL are arranged at an angle of 40° to the longitudinal axis xB and thus, in particular, at the same angle to the sensor edge, with maximum length. The secondary lines NL are arranged orthogonally to the main lines HL. The grid structure 32 of the bond pad 14 is regular; therefore, the spacing between the main lines and the secondary lines is equal. The main lines HL and secondary lines NL form square recesses 34 with a diagonal length of 83 pm. The resulting pattern repeats at regular intervals with a pattern repeat of 79 pm.

[0255] The grid pattern has an area coverage of 39%, i.e. the sum of the areas of the recesses 34 corresponds to 39% of the area of ​​the side 42 of the bond pad 14 facing the bond layer 16.

[0256] On the area of ​​the bond pad 14 facing the meander, i.e., the functional structure 30, which covers approximately 7% of the bond pad's length, the glass paste for creating the barrier line 26 is screen-printed and fired. The glass of the barrier line 26 fills the underlying recesses 34 of the network structure 34 of the bond pad 14 and establishes direct contact with the substrate 12. The glass also covers the confluence area 28 of the meander. Due to the glass interruptions of the bond pad 14, the diffusion path of foreign atoms from the subsequently applied bond layer 16 into the functional structure 30 is increased.

[0257] The silver-rich bonding layer 16, as well as any backside metallization, is produced by screen printing. A paste consisting of silver particles, a small proportion of platinum particles, low-melting-point bismuth oxide-containing glass frit, organic binders, and solvents is used. The paste is baked at 600°C.

[0258] The assembly produced up to that point is then separated by sawing or by scoring and breaking, so that 100 finished sensors are available.

[0259] After at least one of the sensors 10 has been sintered onto the power electronics assembly or the electronic device, a lead element 52 in the form of a bond wire is bonded to each of the bond pads 14, essentially parallel to the edges. M / NEXE-080-PC

[0260] 35

[0261] For such a sensor arrangement 50 with a sensor 10, tensile tests performed showed a high resistance to wire breakage with the inclusion of an area of ​​the bond layer.

[0262] Additionally, the resistance of functional structure 30, i.e., the meander resistance, was checked. These measurements showed that no significant increase in resistance due to diffusion of silver into the meander region could be detected.

[0263] Example 2:

[0264] First, the sensors 10 are manufactured as follows:

[0265] On one side, the cuboid substrate 12 made of aluminum oxide is coated with a thin layer of platinum. The substrate is sufficiently large to accommodate a large number of sensors side by side. This platinum layer is approximately 1 pm thick and is applied by physical vapor deposition (PVD). The meandering functional structure 30, an adjustment structure, and two bond pads 14 are patterned from the continuous metal layer by photolithography. The functional structure 30 of the component has a nominal resistance of 1000 ohms, which allows a quality class F 0.6 (2B) to be achieved.

[0266] The grid structure 32 of the bond pads 14 is a lattice pattern and features main lines HL and secondary lines NL. These main lines HL are arranged at an angle of 40° to the longitudinal axis xB and thus, in particular, at the same angle to the sensor edge, with maximum length. The secondary lines NL are arranged orthogonally to the main lines HL. The grid structure 32 of the bond pad 14 is regular; therefore, the spacing between the main lines and the secondary lines is equal. The main lines HL and secondary lines NL form square recesses 34 with a diagonal length of 83 pm. The resulting pattern repeats at regular intervals with a pattern repeat of 79 pm.

[0267] The grid pattern has an area coverage of 39%, i.e., the sum of the areas of the recesses 34 corresponds to 39% of the area of ​​the side 42 of the bond pad 14 facing the bond layer 16. M / NEXE-080-PC

[0268] 36

[0269] The silver-rich bonding layer 16, as well as any backside metallization, is produced by screen printing. A paste consisting of silver particles, a small proportion of platinum particles, low-melting-point bismuth oxide-containing glass frit, organic binders, and solvents is used. The paste is baked at 600°C.

[0270] Subsequently, this arrangement produced up to that point is separated by sawing or by scoring and breaking, so that 100 finished sensors 10 are available.

[0271] After sintering at least one of the sensors 10 onto the power electronics assembly or the electronic device, a lead element 52 in the form of a bond wire is bonded to each of the bond pads 14 essentially parallel to the edges.

[0272] In some tests, it was found that even immediately after singulation...

[0273] - in four sensors the electrical contact between the functional structure 30, i.e. the meander, and bond pad 14 with bond layer 16 has broken off,

[0274] - seven sensors in the area of ​​functional structure 30, i.e. the meander, and bond pad 14 with bond layer 16 are pre-damaged, but electrical contact still exists between meander and bond pad,

[0275] - in the majority of the sensors, the resistance of the meander has increased by 3-5 ohms.

[0276] Despite the electrical faults, all 100 sensors could be sintered onto the power electronics and the 52 connecting elements showed a stable bond with the bonding layer.

[0277] For such a sensor arrangement 50 with a sensor 10, tensile tests performed showed a high resistance to wire breakage with the inclusion of an area of ​​the bond layer.

[0278] Example 3:

[0279] First, the sensors 10 are manufactured as follows: M / NEXE-080-PC

[0280] 37

[0281] On one side, the cuboid substrate 12 made of aluminum oxide is coated with a thin layer of platinum. The substrate is sufficiently large to accommodate a large number of sensors side by side. This platinum layer is approximately 2 pm thick and is applied using a thin-film process, such as physical vapor deposition (PVD). The meandering functional structure 30, alignment structures, and two bond pads 14 are partially etched from the continuous metal layer. The functional structure 30 of the component has a nominal resistance of 1000 ohms, enabling an accuracy of ±0.24%.

[0282] The network structure 32 of the bond pads 14 is a grid pattern and features main lines HL and secondary lines NL. These main lines HL are arranged parallel to the longitudinal axis xB and thus to the sensor edge with their maximum length. The secondary lines NL are arranged orthogonally to the main lines HL. The network structure 32 of the bond pad 14 is regular; therefore, the spacing between the main lines and the secondary lines is equal. The main lines HL and secondary lines NL form square recesses 34 with a diagonal length of 83 pm. The resulting pattern repeats at regular intervals with a pattern repeat of 79 pm.

[0283] The grid pattern has an area coverage of 39%, i.e. the sum of the areas of the recesses 34 corresponds to 39% of the area of ​​the side 42 of the bond pad 14 facing the bond layer 16.

[0284] The glass paste for creating the barrier line 26 is screen-printed and fired onto the area of ​​the bond pad 14 facing the meander, i.e., the functional structure 30, which covers approximately 7% of the bond pad's length. The glass of the barrier line 26 fills the underlying recesses 34 of the network structure 34 of the bond pad 14 and comes into direct contact with the substrate 12. Due to the glass interruptions of the bond pad 14, the diffusion path of foreign atoms from the subsequently applied bond layer 16 into the functional structure 30 is increased.

[0285] The silver-rich bonding layer 16, as well as any backside metallization, is produced by screen printing. A paste consisting of silver particles, a small proportion of platinum particles, and low-melting-point bismuth (M / NEXE-080-PC) is used.

[0286] 38 oxide-containing glass frits, as well as organic binders and solvents. The paste is baked at 600°C.

[0287] The resulting arrangement is then separated by sawing or scoring and breaking, so that 100 finished sensors are available.

[0288] After sintering at least one of the sensors 10 onto the power electronics assembly or the electronic device, a lead element 52 in the form of a bond wire is bonded to each of the bond pads 14 essentially parallel to the edges.

[0289] The arrangement of the main lines HL in combination with the provided blocking line ensures that breaks between meander (functional structure 30) and bond layer 16 can be suppressed, so that the nominal resistance of the sensor 10 or the sensor arrangement 50 can continue to be maintained without offset.

[0290] After the sensor assembly is produced by solid sintering on the back of the sensors 10 and the connecting element 52 is placed on the bond layer 16, in contrast to Example 1, a bond break occurs in 2% of all sensors 10, taking with it a piece of the bond layer 16 and the underlying area of ​​the bond pad 14.

[0291] Example 4:

[0292] First, the sensors 10 are manufactured as follows:

[0293] On one top side, the cuboid substrate 12 made of aluminum oxide is coated with a thin platinum film. This platinum layer is approximately 1 pm thick and is applied by physical vapor deposition (PVD). The meandering functional structure 30, alignment structures, two bond pads 14, and the oval recess 40 are patterned from the continuous metal layer by photolithography. The bond pad no longer has a platinum layer in the area of ​​the recess 40. The functional structure 30 of the component has a nominal resistance of 1000 ohms, which allows a quality class F 0.6 (2B) to be achieved. M / NEXE-080-PC

[0294] 39

[0295] The network structure 32 of the bond pads 14 is a grid pattern and features main lines HL and secondary lines NL. These main lines HL are arranged parallel to the longitudinal axis xB and thus to the sensor edge with their maximum length. The secondary lines NL are arranged orthogonally to the main lines HL. The network structure 32 of the bond pad 14 is regular; therefore, the spacing between the main lines and the secondary lines is equal. The main lines HL and secondary lines NL form square recesses 34 with a diagonal length of 83 pm. The resulting pattern repeats at regular intervals with a pattern repeat of 79 pm.

[0296] The grid pattern has an area coverage of 39%, i.e. the sum of the areas of the recesses 34 corresponds to 39% of the area of ​​the side 42 of the bond pad 14 facing the bond layer 16.

[0297] The glass paste for creating the barrier line 26 is screen-printed and fired onto the area of ​​the bond pad 14 facing the meander, i.e., the functional structure 30, which covers approximately 7% of the bond pad's length. The glass of the barrier line 26 fills the underlying recesses 34 of the network structure 34 of the bond pad 14 and comes into direct contact with the substrate 12. Due to the glass interruptions of the bond pad 14, the diffusion path of foreign atoms from the subsequently applied bond layer 16 into the functional structure 30 is increased.

[0298] The silver-rich bonding layer 16, as well as a reverse-side metallization, is produced by screen printing. A paste consisting of silver particles, a small proportion of platinum particles, low-melting-point bismuth oxide-containing glass frit, organic binders, and solvents is used. The paste is baked at 600°C.

[0299] The resulting arrangement is then separated by sawing or scoring and breaking, so that 100 finished sensors are available.

[0300] After at least one of the sensors 10 has been sintered onto the power electronics assembly or the electronic device, a connecting element 52 in the form of a bond wire is bonded to the bond pads 14, essentially parallel to the edges, in the connection area 20. The connection area 20 is congruent with the recess 40. M / NEXE-080-PC

[0301] 40

[0302] The tests carried out, such as a tensile test, showed neither meander breakage nor increased resistance due to silver diffusion, nor wire breakage involving the bond layer.

[0303] Reference symbol list

[0304] 10 Sensor

[0305] 12 Substrat

[0306] 14 Bondpad

[0307] 16 Bond layers

[0308] 16a, b, c Bond layer single layer

[0309] 18 first page

[0310] 20 Connection area

[0311] 22 second page

[0312] 24 contact area

[0313] 26 Block line

[0314] 26a first blocking line section

[0315] 26b second blocking line section

[0316] 28 Junction area

[0317] 30 Functional structure

[0318] 32 Network structure

[0319] 34 recess

[0320] 36 Bond area

[0321] 38 Detention area

[0322] 39 circumferential edges

[0323] 40 Exclusion

[0324] 41 Demarcation

[0325] 42 Bondpad surface

[0326] 44 first end

[0327] 50 Sensor arrangement

[0328] 52 Supply element

[0329] 54 electronic device

[0330] L maximum longitudinal extent of the bond pad

[0331] Lvb Longitudinal extent of the connection area

[0332] Lhb Longitudinal extent of the detention area

[0333] The longitudinal extent of the boundary

[0334] Ba Width extent of the holding area M / NEXE-080-PC xB Longitudinal axis

[0335] HA Main Axle

[0336] HL Main Line

[0337] NL secondary line a angle xV longitudinal axis connection area

Claims

December 18, 2025 Yageo Nexensos GmbH M / NEXE-080-PC Sensor and sensor arrangement Claims 1. Sensor (10), comprising - a substrate (12) of an electronic device, - at least one Bondpad (14), - at least one bond layer (16), wherein the bond pad (14) is arranged between the substrate (12) and the bond layer (16), and wherein a connection area (20) for connecting a lead element (52) is provided on a first side (18) of the bond layer (16), and wherein a contact area (24) is provided on a second side (22) of the bond layer (16) opposite the first side (18), and - at least one locking line (26), wherein the locking line (26) is arranged between the bond pad (14) and the bond layer (16) and wherein at least one entry area (28) of a functional structure (30) on the bond pad (14) is covered by the locking line (26).

2. Sensor (10), in particular sensor (10) according to claim 1, comprising - a substrate (12) of an electronic device, - at least one bond pad (14), and - at least one bond layer (16), wherein the bond pad (14) is arranged between the substrate (12) and the bond layer (16), wherein a connection area (20) for connecting a lead element (52) is provided on a first side (18) of the bond layer (16), and wherein a contact area (24) is provided on a second side (22) of the bond layer (16) opposite the first side (18), and wherein the bond pad (14) has at least one recess (40), wherein the at least one recess (40) is assigned to the second side (22) of the bond layer (16).

3. Sensor (10) according to claim 1 or 2, characterized by the fact that the bond pad (14) has a mesh structure (32) with a plurality of, in particular regular, recesses (34) such that at least the contact area (24) of the bond layer (16) and the substrate (12) are in contact with each other and / or that the bond pad (14) has a mesh structure (32) with a plurality of, in particular regular, recesses (34) such that at least one / the barrier line (26) and the substrate (12) are in contact with each other.

4. Sensor (10) according to claim 3, characterized by the fact that the mesh structure (32) is provided at least in a bond area (36) of the bond pad (14), wherein the bond area (36) corresponds to the contact area (24) of the bond layer (16) and wherein the bond area (36) and the contact area (24) are contacted together.

5. Sensor (10) according to one of claims 3 to 4, characterized in that the connection area (20) of the first side (18) and / or the contact area (24) of the second side (22) of the bond layer (16) has a longitudinal axis (xB) along its maximum longitudinal extent (Lvb), and that the mesh structure (32) has a principal axis (HA) for orienting a plurality of principal lines (HL) and a plurality of minor lines (NL), wherein a) the longitudinal axis (xB) of the connection area (20) and the principal axis (HA) of the mesh structure (32) are arranged at an angle (o) of 30° to 60°, preferably substantially at an angle (o) of 40° or 50°, to each other, or b) the longitudinal axis (xB) of the connection area (20) and the principal axis (HA) of the mesh structure (32) are arranged substantially parallel or parallel to each other.

6. Sensor (10) according to one of the preceding claims, characterized by the fact that the barrier line (26) covers at least 3%, preferably at least 5%, further preferably at least 7%, of one side (42) of the bond pad (14) facing the bond layer (16).

7. Sensor (10) according to any one of claims 3 to 6, characterized by the fact that an adhesive area (38) is formed in the contact area (24) of the bond layer (16), wherein the adhesive area (38) is arranged within a boundary (41), wherein the boundary (41) has a maximum longitudinal extent (La) with a minimum length of at least 100 pm, preferably at least 200 pm, and a maximum length of at most 400 pm, preferably at most 300 pm, and wherein the boundary (41) has a maximum width extent (Ba) with a minimum width of at least 20 pm, preferably at least 50 pm, and a maximum width of at most 100 pm, preferably at most 75 pm, and wherein the boundary (41) is arranged at a distance (D) of at least 200 pm from the circumferential edges (39) of the bond pad (14). is, wherein the detention area (38) in the contacted state is arranged within the demarcation (41),and that the bonding area (38) at least partially, and in particular completely, covers at least one recess (34), preferably at least two recesses (34), and more preferably at least three recesses (34), of the mesh structure (32) of the bond pad (14), so that the bonding area (38) is in contact with the substrate (12).

8. Sensor (10) according to claim 7, characterized by a maximum longitudinal extent (Lhb) of the adhesion area (38) being arranged substantially perpendicular or perpendicular to the longitudinal extent (Lvb) of the connection area (20).

9. Sensor (10) according to one of claims 3 to 8, which indicates that at least a proportion of the multitude of recesses (34) of the net structure (32) of the bond pad (14) are arranged under the locking line (26) and / or under the bond layer (16).

10. Sensor (10) according to one of claims 3 to 8, characterized by the plurality of recesses (34) of the mesh structure (32) having a mean structure size, wherein the mean structure size corresponds to a maximum of 20%, preferably a maximum of 15%, more preferably a maximum of 12%, of a maximum longitudinal extent L of the bond pad (14).

11. Sensor (10) according to one of claims 2 to 9, in particular according to one of claims 3 to 9, characterized by the fact that the sum of the surface areas of the plurality of recesses (34) of the bond pad (14) corresponds to 20% to 80%, preferably 30% to 70%, more preferably 33% to 60%, of the surface area of ​​the side (42) of the bond pad (14) facing the bond layer (16).

12. Sensor (10) according to one of the preceding claims, characterized by the fact that the locking line (26) comprises at least one of the following materials: glass, glass ceramic and / or metal oxide, in particular aluminum oxide and / or zirconium dioxide and / or magnesium oxide.

13. Sensor (10) according to one of claims 2 to 11, characterized by the fact that the at least one recess (40) of the bond pad (14) has at least partially an oval and / or round and / or rectangular shape.

14. Sensor (10) according to one of claims 2 or 12, characterized by the fact that the area of ​​the at least one recess (40) of the bond pad (14) is 15% to 60%, preferably 20% to 50%, more preferably 25% up to 30% of the area of ​​the side (42) of the bond pad (42) facing the bond layer (16).

15. Sensor (10) according to one of the preceding claims, characterized by the fact that the at least one bond pad (14) is designed as a thin-film structure and / or the at least one bond layer (16) is designed as a thick-film structure, which is produced in particular in at least one baking process.

16. Sensor (10) according to claim 15, characterized by the fact that the bond layer (16) is formed from a baked-on metal paste comprising oxide particles, in particular crystalline particles and / or glass frit and / or vitrified particles, wherein the metal paste was applied in a structured manner, in particular by means of a screen printing process, stencil printing process or pad printing process.

17. Sensor (10) according to one of the preceding claims, characterized in that the barrier line (26) is arranged between the at least one bond pad (14) and the at least one bond layer (16) in such a way that it acts only section by section as a separating layer and / or diffusion protection layer between the bond pad (14) and the bond layer (16).

18. Sensor (10) according to one of the preceding claims, characterized in that the at least one bond pad (14) is formed from a substantially silver-free platinum material and / or the at least one bond layer (16) comprises an alloy having platinum and silver with a silver concentration of at least 10 wt.% based on the total metal content of the alloy.

19. Sensor (10) according to one of the preceding claims, characterized in that the electrical voltage difference applied across the thickness of the barrier line (26) during operation of the sensor (10) is less than 0.1 V, preferably less than 0.03 V, more preferably 0.01 V.

20. Sensor (10) according to one of the preceding claims, characterized in that the insulation resistance of the barrier line (26) is greater than 10 at a temperature of up to 400 °C 6 Ohm over the thickness of the barrier line (26) is.

21. Sensor (10) according to one of the preceding claims, characterized in that the bond pad (14) has several recesses (34) which are penetrated by the locking line (26).

22. Sensor arrangement (50) comprising a sensor (10) according to one of the preceding claims, and a connecting element (52) for making an electrical connection with the sensor (10), wherein the connecting element (52) is connected to the sensor (10) via the connection area (20) of the first side (18) of the bond layer (16).

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