Sensor unit for electronic device, electronic device, and method for mounting sensor element - Patents.com

Abstract

According to one embodiment, a sensor unit (10) for an electronic device (100) comprises a sensor element (1) for measuring a physical quantity within the electronic device and a contact element (2) configured to be mechanically biased. The contact element is fixed to and electrically connected to the sensor element. The sensor unit is configured to be attached to a component of the electronic device by placing the sensor element on a measurement surface of the component and mechanically biasing the contact element such that the mechanically biased contact element applies a force to the sensor element acting in a direction toward the measurement surface.

Description

[Technical Field]

[0001] The present disclosure relates to a sensor unit for an electronic device, an electronic device, and a method for mounting a sensor element. Summary of the Invention [Problem to be solved by the invention]

[0002] It is an object to provide an improved sensor unit for an electronic device, for example, a sensor unit that can be easily and reliably attached to an electronic device. A further object is to provide an electronic device having such a sensor unit. Another object is to provide an improved method for attaching a sensor element, for example, a method of using the above-mentioned sensor unit to attach a sensor element. [Means for solving the problem]

[0003] SUMMARY OF THE DISCLOSURE Embodiments of the present disclosure relate to improved sensor units for electronic devices, improved electronic devices, and improved methods for attaching sensor elements.

[0004] First, a sensor unit for an electronic device is defined. According to one embodiment, a sensor unit for an electronic device comprises a sensor element for measuring a physical quantity in the electronic device and a contact element configured to be mechanically biased, the contact element being fixed to and electrically connected to the sensor element, and the sensor unit is configured to be attached to a component of the electronic device by placing the sensor element on a measurement surface of the component and mechanically biasing the contact element such that the mechanically biased contact element applies a force to the sensor element acting in a direction toward the measurement surface.

[0005] Such a sensor unit can be easily installed in an electronic device, such as a power semiconductor module, even if the electronic device was originally developed without such a sensor element. The contact element can be biased to apply a force to the sensor element, allowing the sensor element to be securely positioned on the measurement surface without using additional connection means such as solder or adhesive. Alternatively, the biased contact element may press the contact element toward or against the measurement surface, thereby forming a secure dry electrical contact between the sensor element and the measurement surface. To maintain the biased state of the contact element, a portion of the contact element can be fixed to it using any structure present in the electronic device, such as a terminal or a plastic housing.

[0006] The sensor element may be, for example, a transducer (measuring instrument transducer) and thus part of a measuring device that responds directly to the measuring instrument. The sensor element may therefore be the first element of a measuring chain. The sensor element is configured to detect a physical quantity, such as temperature, humidity, pressure, acceleration, etc., and in response generates or manipulates an electrical signal that can be read out via a contact element.

[0007] The contact element is at least partially electrically conductive. The contact element may include a contact area that is remote from the sensor element, in particular an area opposite the sensor element, and that can electrically connect the contact element. The contact element provides a conductive path from the sensor element to the contact area. This may make it possible to read the sensor element using the contact element, in particular to receive an electrical signal from the sensor element via the contact element, or to supply an electrical signal to the sensor element via the contact element. The contact element may therefore also be used to supply a voltage and / or a current to the sensor element.

[0008] The contact element may be integrally formed or may consist of several parts. For example, the contact element may be made of or include metal. That the contact element is configured to be mechanically biased means that at least a portion / section of the contact element is resilient and deformable to move the contact element from its relaxed state to its biased state. In the biased state, the contact element tends to automatically return to its relaxed state. At least one resilient portion of the contact element may, for example, be reversibly deformable. The contact element may include one or more deformable, resilient portions / sections, such as a spring. When moving the contact element from its relaxed state to its biased state, the at least one resilient or deformable portion may, for example, be compressed and / or bent and / or deflected. Mechanically biased and mechanically stressed are used synonymously.

[0009] The contact element is mechanically fixed to the sensor element. This means that the contact element and the sensor element form a composite. The connection between the contact element and the sensor element may be a form-fit and / or a pressure-fit and / or a material-lock (bonded) connection. For example, this connection is not non-destructively removable. When the sensor unit is installed, it is installed together with the composite of the sensor element and the contact element. That is, the contact element and the sensor element are not installed separately.

[0010] When the sensor unit is attached to a component of an electronic device, the sensor element, e.g., its bottom side, can be arranged on a measurement surface of the component. The bottom side of the sensor element is, for example, the side of the sensor element opposite to the side on which the connection between the contact element and the sensor element is established. Thus, the attached sensor element may be arranged between the measurement surface and at least a part of the contact element. The measurement surface of the component is herein meant to be the surface on which a physical quantity is measured using the sensor element.

[0011] When attaching the sensor unit, the contact element can be mechanically biased, i.e., in a biased state, so that it exerts a force on the sensor element towards the measurement surface. As an example, the sensor unit is configured such that when the sensor unit is taken by holding and / or fixing the sensor unit at a particular region of the contact element, for example an end region thereof, and then the sensor element is placed on the measurement surface, and then an attempt to press the sensor element further towards the measurement surface causes the contact element to be mechanically biased, i.e., at least one deformable portion of the contact element to be deformed.

[0012] When the contact element is then fixed so as to remain biased against the member having the measurement surface, the sensor element is securely positioned on the measurement surface without the need for a material-locking connection between the sensor element and the measurement surface, e.g., the connection between the sensor element and the measurement surface is solely of a form-fit and / or force-fit nature.

[0013] For example, the contact element is configured to apply a force of at least 0.01 N or at least 0.1 N to the sensor element when energized.

[0014] According to a further embodiment, the sensor element is a temperature sensor. For example, the sensor element is a temperature-sensitive resistor, also known as a "thermistor." The sensor element may be a platinum resistor, such as an NTC, PTC, PT100, or PT1000, or a thermocouple. Alternatively, the sensor element may be a humidity sensor, an acceleration sensor, or a pressure sensor.

[0015] Indeed, there is a high level of customer interest in temperature monitoring of, for example, power semiconductor devices (also referred to herein as "power semiconductor chips" or simply "chips") or power semiconductor modules during operation. Temperature monitoring is typically used to protect against overheating of the chip, for example in overcurrent situations, or to monitor the degradation state of the power semiconductor module, for example with respect to aging of bonding connections that affect the thermal resistance and thus the chip temperature.

[0016] According to at least one embodiment, the contact element comprises or is one of a spring contact element or a pressure contact pin. The spring contact element has, for example, a serpentine-shaped region and / or a V-shaped region and / or a U-shaped region and / or a spring washer region and / or a spring region that can be compressed to place the contact element in a biased state. Additionally or alternatively, the spring contact element can have a cantilever-shaped portion that can be bent to place the spring contact element in a biased state. The spring contact element may be integrally formed.

[0017] The crimping pin comprises a body, e.g., a barrel or tubular body / sleeve, a tip element, e.g., a plunger, and one or more springs, e.g., spiral springs, that can be compressed to bias the contact element. The tip element is movably mounted relative to the body and can be moved further toward or into the body by compressing the spring. The crimping pin is, for example, an elongated element. The tip element of the crimping pin may be fixed to the sensor element.

[0018] According to further embodiments, the contact elements are fixed to the sensor element by a material locking connection or a bonded connection, respectively. The electrical connection may also be established by a material locking connection. For example, the contact elements are soldered, sintered or glued to the sensor element, or the fixed connection is realized by any other applicable bonding method.

[0019] According to a further embodiment, the contact element comprises a means for screwing the contact element into a thread of the electronic device, for example into a threaded hole of an auxiliary terminal. For example, the contact element comprises an external thread. However, other means for fixing the contact element to the electronic device are also conceivable, such as contours or ribs on the outer surface of the contact element that can be embedded in the molding / resin to fix the contact element to the electronic device in a form-fitting manner.

[0020] According to a further embodiment, the contact element comprises a terminal area, which is configured for electrical connection. When mounted on an electronic device, the terminal area may be exposed to allow external electrical contact. The terminal area may be formed, for example, by an end of the contact element facing away from and / or facing the sensor element, e.g., by the above-mentioned contact area. For example, the terminal area may be formed by a longitudinal end of the insulation displacement pin opposite the pin element.

[0021] According to a further embodiment, the contact element comprises a terminal structure. The terminal area may be part of the terminal structure. The terminal structure is connected, for example, to a spring contact or insulation displacement pin of the contact element. The terminal structure may be a sheet-like structure or a hollow cylinder with a screw thread, such as a nut. It may be made of metal. When attached to the electronic device, the sheet-like structure may extend substantially parallel to the main extension plane of the electronic device. For example, the terminal structure extends obliquely or perpendicularly to the main extension direction of the insulation displacement pin.

[0022] For example, the spring contacts or insulation displacement pins of the contact elements may be connected to the terminal structure by soldering, welding, crimping, gluing or screwing, or the spring contacts or insulation displacement pins may be integrally formed with the terminal structure.

[0023] According to a further embodiment, the sensor element comprises a top electrode on a top surface of the sensor element. Additionally, the sensor element may comprise a bottom electrode on a bottom surface of the sensor element, the bottom surface being opposite the top surface.

[0024] The top and bottom electrodes are, for example, metal regions of the sensor element, configured to electrically connect the sensor element for readout and / or to supply current and / or voltage to the sensor element.

[0025] According to a further embodiment, the contact element is electrically connected to and fixed to the top electrode of the sensor element.

[0026] According to a further embodiment, the bottom electrode of the sensor element, in particular the side of the sensor element opposite the top electrode, is exposed in the unattached configuration of the sensor unit. That is, in the unattached configuration, the bottom electrode is freely accessible. For example, when attached to a measurement surface, a (dry) electrical contact is formed between the bottom electrode and the measurement surface, so that the sensor element can be read out via the measurement surface on the one hand and via the contact element on the other hand.

[0027] Next, an electronic device is defined. The electronic device described herein may be, for example, a power semiconductor module or an assembly including a power semiconductor module.

[0028] According to one embodiment, an electronic device comprises a sensor unit according to any of the embodiments described herein. The electronic device further comprises a member having a measurement surface on which a physical quantity is measured using a sensor element. The sensor element is disposed on the measurement surface. The contact element is mechanically biased to apply a force to the sensor element acting in a direction towards the measurement surface.

[0029] Since an electronic device comprises a sensor unit according to any of the embodiments described herein, all features disclosed for the sensor unit are also disclosed for the electronic device, and vice versa.

[0030] The sensor element may be arranged directly on the measurement surface, i.e. adjacent to the measurement surface, such that at least thermal contact can be formed between the measurement surface and the sensor element.

[0031] For example, the contact element is fixed in the electronic device so as to be maintained in its biased state. For example, the contact element is fixed so as to prevent the contact element or any part thereof from moving away from the measurement surface to enter a relaxed state. Meanwhile, because the sensor element is disposed on the measurement surface, movement of the sensor element toward the measurement surface to enter a relaxed state is also prevented. The biased contact element can press the sensor element against the measurement surface. In this way, reliable contact between the measurement surface and the sensor element can be achieved. Loss of contact between the sensor element and the measurement surface can be prevented. Lateral movement of the sensor element is also difficult.

[0032] According to further embodiments, the sensor elements are arranged on the measurement surface or the respective component with and without a material-locking connection (joint) between them. For example, the sensor elements can be non-destructively removed from the measurement surface. In one example, the sensor elements are connected to the measurement surface purely by pressure and / or form-fitting connection. A non-material-locking connection between two elements is also called a "dry connection."

[0033] The sensor element may be electrically connected to the measuring surface or the member, respectively. Electrical contact between two elements established without a material-locking connection, i.e., by a dry connection, is referred to herein as a "dry electrical contact." For example, electrical contact between the measuring surface and the sensor element is provided exclusively by a dry electrical contact.

[0034] According to a further embodiment, the electronic device comprises a power semiconductor device. As an example, the power semiconductor device is a switching device. The power semiconductor device may be an IGBT, a MOSFET, a HEMT, a diode, or a thyristor. In this case, the electronic device is, for example, a power semiconductor module having one or more power semiconductor devices or comprises such a module.

[0035] The power semiconductor module may include a substrate having a top metallization and, optionally, a bottom metallization. At least one power semiconductor device may be attached to the top surface of the substrate where the top metallization is located, for example, attached to the top metallization. The substrate may be, for example, a DBC (Direct Bonded Copper) substrate, a DBA (Direct Bonded Aluminum) substrate, an AMB (Active Metal Bracing) substrate with an insulating ceramic layer, or an IMS (Isolated Metal Substrate) with an insulating resin layer. Furthermore, the power semiconductor module may include terminals (main terminals and, optionally, auxiliary terminals) for external electrical connection. The terminals may be realized, for example, by sheet-like and / or metallic and / or integrally formed terminal structures. Other shapes of the terminals, such as hollow cylinders with nut-like threads, are also possible. Terminal areas of the terminal structures are exposed to enable external electrical contact. The terminal structures may be bonded to or realized by the top metallization. The terminals can be used to connect the chip directly, but can also control electronic devices.

[0036] The power semiconductor module may further include a housing body. The housing body may be formed of an electrically insulating material such as a resin and / or a gel. The power semiconductor device may be embedded in the housing body. The terminal structure may be at least partially embedded in the housing body. A terminal region of the terminal structure may protrude from the housing body, for example, at a side surface thereof. The housing body may include a housing frame surrounding a cavity. The cavity may be filled with a gel.

[0037] The power semiconductor module may further include a base plate, e.g., for cooling. The substrate may be attached to the base plate, e.g., with the bottom metallization facing the base plate. The base plate may be made of a metal such as Cu or Al or an alloy thereof, or a composite material such as aluminum silicon carbide or magnesium silicon carbide. The base plate may include cooling structures, such as pin fins or ribs, on the side opposite the substrate.

[0038] Here, the lateral direction is a direction parallel to the main extension plane of the substrate, and the vertical direction is a direction perpendicular to the main extension plane of the substrate.

[0039] According to a further embodiment, the sensor element is arranged on the power semiconductor device. According to a further embodiment, the sensor element is arranged in an area adjacent to the power semiconductor device. For example, the sensor element is arranged on a top metallization of the substrate next to the power semiconductor device and / or between two adjacent power semiconductor devices. The top metallization can then form the measurement surface.

[0040] Placing the sensor element on the power semiconductor device has several advantages over placing the sensor element on a substrate adjacent to the power semiconductor device, or even on a separate substrate of the electronic device adjacent to the substrate on which the power semiconductor device is mounted. For example, the quality of the chip temperature determination improves as the distance between the chip and the temperature sensor decreases. In fact, in this case, the true chip temperature can be more accurately derived from the sensor readings using a thermal model. Furthermore, when the sensor element is placed directly on the chip, the temperature change and the corresponding measurement time delay caused by the large distance can be significantly reduced.

[0041] An additional advantage of placing the sensor element on the power semiconductor device is that if two or more heat-generating chips are mounted on the board, the sensor reading will refer primarily to one chip, not an average of the chips. If the sensor element is placed between chips on the board, the measured temperature may not refer to the temperature of the most thermally unfavorable or most degraded chip. In the worst case, a severe degradation of the bonded connection under one chip may not be detected.

[0042] Furthermore, when the sensor element is placed on the chip, it can be avoided that an excessively high temperature of the chip goes undetected because a deteriorated die bond does not conduct heat.

[0043] Additionally, placing the sensor element on the top metallization next to the power semiconductor device consumes space on the substrate surface, reducing the available space for the chip, which can also negatively impact thermal resistance and therefore the rated cost per ampere.

[0044] Also, many were originally developed without incorporating a sensor element. As a result, there may not be any available area on the board for the placement of a sensor element. However, customer demand is increasingly moving towards the implementation of thermal sensors.

[0045] An electronic device may include several of the above sensor units. For example, several power semiconductor devices are each assigned a sensor unit with a respective sensor element. One or more sensor elements of one or more sensor units may be attached to a top metallization of one or more substrates next to or between one or more power semiconductor devices, and one or more sensor elements of one or more sensor units may be attached to one or more power semiconductor devices. For example, there may be one such sensor unit per substrate.

[0046] According to a further embodiment, the measurement surface is formed by a top electrode of the power semiconductor device. The top electrode of the power semiconductor device may be, for example, a source / emitter electrode or a drain / collector electrode. The top electrode may be made of a metal such as Cu or Al or a corresponding alloy.

[0047] According to a further embodiment, the bottom electrode of the sensor element is in dry electrical contact with the top electrode of the power semiconductor device. The contact between the bottom electrode of the sensor element and the top electrode of the power semiconductor device may additionally be thermal contact.

[0048] If the sensor element is attached to the top metallization of the substrate, there may also be a dry electrical contact between the bottom electrode of the sensor element and the measuring surface (top metallization).

[0049] The sensor reading of the sensor element may be, for example, between the contact element and an output terminal (e.g., an AC terminal) of the electronic device, or the sensor reading may be between the contact element and an input terminal (e.g., a DC+ or DC- terminal) of the electronic device.

[0050] According to a further embodiment, the contact element is electrically and mechanically connected, in particular fixed, to an auxiliary terminal of the electronic device. The auxiliary terminal is, for example, formed by an auxiliary terminal structure of the electronic device. The auxiliary terminal structure is, for example, a sheet metal element, a nut, or a hollow (metal) cylinder. The auxiliary terminal is different from the main terminal or power terminal of the electronic device. The main terminal may be an AC, DC-, or DC+ terminal. In particular, the auxiliary terminal is configured to carry less current than the main terminal. The auxiliary terminal may be partially embedded in the housing body of the electronic device. The auxiliary terminal may be a terminal for controlling, e.g., measuring / detecting, the power semiconductor device. They may be an auxiliary emitter or collector terminal, a gate terminal, or a terminal for connecting a sensor.

[0051] According to a further embodiment, the contact element is electrically and mechanically connected to the auxiliary terminal by a screw connection, although other connections such as soldering, welding, crimping or adhesive bonding are also possible.

[0052] The auxiliary terminal is, for example, a terminal of an electronic device that can be electrically connected from the outside. That is, the terminal area of ​​the auxiliary terminal is exposed and freely accessible. For example, the terminal area of ​​the auxiliary terminal is exposed and / or protrudes from the side surface of the housing body. Alternatively, the auxiliary terminal may be exposed and / or protrude from the top surface of the housing body, for example, when the auxiliary terminal is a nut, a vertical pin, or a hollow sleeve.

[0053] In addition to connecting the contact elements to auxiliary terminals, other methods of securing the contact elements within the electronic device are also contemplated.

[0054] According to a further embodiment, the contact element is fixed to an electrical insulating element of the electronic device, such as a housing body and / or a plastic body. This means, in particular, that there is a direct connection between the contact element and the electrical insulating element. Fixing to the electrical insulating element can keep the contact element mechanically biased. For example, the contact element can be assembled to the housing body and tightly enclosed by the housing body. Alternatively, a (for example, metal) nut can be embedded in the housing body and the contact element can be screwed onto the nut.

[0055] According to a further embodiment, a portion of the contact element is exposed, for example at a top surface of the electronic device. The exposed portion can constitute a terminal area of ​​the contact element for an external electrical connection of the contact element. The sensor element can be electrically supplied and / or read out via the exposed portion.

[0056] According to a further embodiment, a thermally conductive material is disposed between the measurement surface and the sensor element. The thermally conductive material may be a paste filled with fine particles, for example, conductive particles. The thermally conductive material may be electrically conductive or electrically insulating. The paste may be liquid and / or viscous. Alternatively, the thermally conductive material may be a thermally conductive sheet (e.g., an elastic sheet).

[0057] According to a further embodiment, an electronic device comprises at least one, i.e., one or more, power semiconductor modules and a cooler for the power semiconductor modules. The cooler may be a carrier for the power semiconductor modules. The cooler is configured, for example, to conduct a coolant. The cooler may comprise cooling channels for the coolant. The cooler may be made of a metal, such as copper or aluminum. The power semiconductor modules may be mounted on the cooler with a bottom metallization and / or a base plate facing the cooler.

[0058] According to a further embodiment, the measurement surface is formed by the cooler, for example by its upper surface. The temperature of the cooler can then be measured using the sensor element. A dry electrical contact may be formed between the cooler and the sensor element.

[0059] According to a further embodiment, the measurement surface is formed by the surface of the base plate. The sensor element may then be arranged next to the substrate or between two adjacent substrates attached to the base plate.

[0060] According to a further embodiment, at least one of the measurement surface and the surface of the sensor element facing the measurement surface is roughened, particularly to increase the contact area. The roughened surface can imprint on the adjacent surface, thus increasing the contact area. Furthermore, in this way, a form-fit connection can be established. Furthermore, in this way, undesirable oxide layers can be destroyed or impurities / contaminants from the adjacent surface can penetrate.

[0061] According to further embodiments, the roughened surface has an average roughness of at least 1 μm, or at least 1.6 μm, or at least 2 μm.

[0062] Next, a method for attaching the sensor element is defined. An electronic device according to any of the embodiments described herein can be manufactured using this method. Thus, all features disclosed for the electronic device are also disclosed for the method, and vice versa.

[0063] According to one embodiment, a method for attaching a sensor element includes providing a sensor unit according to any one of the embodiments described herein. In a further step, a member for an electronic device is provided. The member has a measurement surface on which a physical quantity of the electronic device is measured using the sensor element. In a further step, the sensor unit is attached to the member. Attaching the sensor unit includes disposing the sensor element on the measurement surface. Attaching also includes mechanically biasing the contact element such that the contact element applies a force to the sensor element acting in a direction toward the measurement surface. Attaching further includes fixing at least a portion of the mechanically biased contact element relative to the member such that the contact element remains in a mechanically biased state.

[0064] The component may be, for example, a power semiconductor device, a substrate or a top metallization of the substrate, a base plate, or a cooler. Thus, the measurement surface may be a top electrode of the power semiconductor device, or a top metallization of the substrate, or a surface of a base plate, or a surface of a cooler.

[0065] The step of positioning the sensor element may be performed before or after energizing the contact element. The sensor element may be positioned directly on the measurement surface so as to be adjacent to the measurement surface. The sensor element is fixed or connected to the measurement surface, for example, exclusively by form-fitting and / or pressure-fitting, i.e., without a material-locking connection formed therebetween (i.e., a dry connection is formed). Thus, the sensor element is not, for example, glued, soldered, sintered, or welded to the measurement surface. Once the sensor element is positioned on the measurement surface, a dry electrical contact may be established between the sensor element and the measurement surface. An energized sensor element may press the sensor element against the measurement surface.

[0066] The contact element may be fixed relative to the member, for example, such that the fixed and biased contact element continues to apply a force to the sensor element in a direction toward the measurement surface, e.g., at least a portion of the contact element remote from the sensor element may be fixed relative to the member.

[0067] According to a further embodiment, securing at least a portion of the mechanically biased contact element to the member comprises threading the contact element into threads of the electronic device. Additionally or alternatively, securing may comprise soldering, sintering, welding, gluing or crimping the contact element to the member of the electronic device.

[0068] After the sensor element is positioned on the measurement surface, a casting process can be performed in which different components of the electronic device, such as a power semiconductor device, are cast in a casting material, which can be a gel. The contact element can be fixed to the component with the measurement surface using the casting process.

[0069] Hereinafter, a sensor unit for an electronic device, an electronic device, and an installation method of a sensor element will be described in more detail based on embodiments with reference to the drawings. The accompanying drawings are included to provide further understanding. In the drawings, elements of the same structure and / or function may be referred to by the same reference numerals. It should be understood that the embodiments shown in the drawings are illustrative representations and are not necessarily drawn to scale. To the extent that elements or components correspond to each other in terms of their functions in different drawings, their description will not be repeated for each of the following drawings. For clarity, elements may not be labeled with corresponding reference numerals in all drawings. [Brief explanation of the drawings]

[0070] [Figure 1] 1 illustrates an exemplary embodiment of a method for attaching a sensor element and different positions in an exemplary embodiment of a sensor unit and an electronic device. [Figure 2] 1 illustrates an exemplary embodiment of a method for attaching a sensor element and different positions in an exemplary embodiment of a sensor unit and an electronic device. [Figure 3] 1 illustrates an exemplary embodiment of a method for attaching a sensor element and different positions in an exemplary embodiment of a sensor unit and an electronic device. [Figure 4] 1 illustrates an exemplary embodiment of a method for attaching a sensor element and different positions in an exemplary embodiment of a sensor unit and an electronic device. [Figure 5] 10 illustrates a further exemplary embodiment of the method, as well as different positions of the sensor unit and the electronic device in a further exemplary embodiment. [Figure 6] 10 illustrates a further exemplary embodiment of the method, as well as different positions of the sensor unit and the electronic device in a further exemplary embodiment. [Figure 7] 10 illustrates a further exemplary embodiment of the method, as well as different positions of the sensor unit and the electronic device in a further exemplary embodiment. [Figure 8] 10 illustrates a further exemplary embodiment of the method, as well as different positions of the sensor unit and the electronic device in a further exemplary embodiment. [Figure 9] 10 illustrates a further exemplary embodiment of the method, as well as different positions of the sensor unit and the electronic device in a further exemplary embodiment. [Figure 10] 10 illustrates a further exemplary embodiment of the method, as well as different positions of the sensor unit and the electronic device in a further exemplary embodiment. [Figure 11] 10 illustrates a further exemplary embodiment of the method and different positions in a further exemplary embodiment of the electronic device. [Figure 12] 10 illustrates a further exemplary embodiment of the method and different positions in a further exemplary embodiment of the electronic device. [Figure 13] 1 shows further exemplary embodiments of an electronic device and a sensor unit; [Figure 14] 1 shows a further exemplary embodiment of an electronic device and a sensor unit. [Figure 15] 10 illustrates a further exemplary embodiment of the method, as well as different positions of the sensor unit and the electronic device in a further exemplary embodiment. [Figure 16] 10 illustrates a further exemplary embodiment of the method, as well as different positions of the sensor unit and the electronic device in a further exemplary embodiment. [Figure 17] 10 illustrates a further exemplary embodiment of the method, as well as different positions of the sensor unit and the electronic device in a further exemplary embodiment. [Figure 18] 1 illustrates a further exemplary embodiment of an electronic device. [Figure 19] 1 illustrates a further exemplary embodiment of an electronic device. DETAILED DESCRIPTION OF THE INVENTION

[0071] 1 shows a location where an exemplary embodiment of a sensor unit 10 for an electronic device 100 is provided. The sensor unit 10 comprises a contact element 2 and a sensor element 1. The contact element 2 is a spring contact element that can be mechanically biased by compression. The contact element 2 is formed of a metal such as, for example, Cu, Al, or steel.

[0072] The sensor element 1 is a temperature sensor, such as a thermistor. It can be an NTC, PTC or platinum resistor (e.g., PT100 or PT1000) or a thermocouple. The sensor element 1 comprises a top electrode 1a and a bottom electrode 1b. Both electrodes 1a, 1b may be electrically conductive, in particular metallic. The electrodes 1a, 1b are arranged to read out the sensor element 1, but can also serve to supply current and / or voltage to the sensor element 1.

[0073] The contact element 2 is fixed and electrically connected to the sensor element 1, i.e., its top electrode 1a. The mechanical and electrical connection between the contact element 2 and the sensor element 1 is realized, for example, by a material-locking connection, such as soldering, sintering, welding or adhesive connection. Since the contact element 2 is electrically conductive, it can be used to read out the sensor element 1.

[0074] 2 shows a further location where an assembly of different components 3, 6 for an electronic device is provided. One component is a substrate 6 having a top metallization 6a. The substrate 6 is, for example, a DBC substrate. Another component is a power semiconductor device 3 attached to the upper surface of the substrate 6 and electrically connected thereto via wire bonds. The power semiconductor device 3 comprises a top electrode 3a that constitutes the measurement surface 30 and whose physical quantity is measured using the sensor element 1 of FIG. 1. By way of example, the power semiconductor device 3 is an IGBT or a power MOSFET, in which the top electrode 3a is the source electrode or the emitter electrode, respectively.

[0075] 3 shows the position where the sensor unit 10 of FIG. 1, having the composite of the sensor element 1 and the contact element 2, is placed on the power semiconductor device 3 so that the sensor element 1 is adjacent to the measuring surface 30. No additional connecting material is used between the sensor element 1 and the measuring surface 30 to form a material-locking connection. Therefore, there is a dry connection between the sensor element 1 and the measuring surface 30.

[0076] In the position of Fig. 4, an exemplary embodiment of an electronic device 100 is shown. The electronic device 100 is a power semiconductor module 100. To obtain this power semiconductor module 100 from the arrangement of Fig. 3, the contact element 2 is compressed or bent, thus assuming its biased state. In this biased state, the contact element 2 exerts a force on the sensor element 1 in a direction towards the measuring surface 30, thereby pressing the sensor element 1 against the measuring surface 30. In this way, the sensor element 1 is securely held on the measuring surface 30 by an increased frictional force (dry connection), and a secure and reliable electrical connection (dry electrical contact) is established between the measuring surface 30 and the sensor element 1.

[0077] The device of Fig. 4 may be manufactured as follows: With the contact elements 2 in an energized state, a resin 61 is applied to the substrate 6, encapsulating a portion of the contact elements 2. After drying of the resin 61, the contact elements 2 are fixed in the energized state. The resulting resin body 61 forms the housing frame 61 of the power semiconductor module 100. The cavity enclosed by the housing frame may be filled, for example, with a gel.

[0078] 4 may alternatively be manufactured as follows: a pre-manufactured housing frame 61 may be attached to the substrate 6, and the contact elements 2 may then be clamped to the housing frame 61 and held in a biased state. Alternatively, the contact elements 2 may be at least partially embedded in the housing frame 61 as an integral part.

[0079] A portion of the contact element 2 on the top surface of the power semiconductor module 100 is not covered by the resin body 61 and is exposed. This portion constitutes a terminal area of ​​the contact element 2 for external electrical connection of the contact element 2. Thus, the sensor element 1 can be read out, for example, via the contact element 2 and a DC or AC terminal of the power semiconductor module 100.

[0080] 5 shows a position where a further exemplary embodiment of the sensor unit 10 is shown. In this case, the contact element 2 is formed by a pressure contact pin. The pressure contact pin is provided with a spring 22 for pressing the tip element or plunger of the pressure contact pin towards the measurement surface and away from the barrel of the hollow sleeve of the pressure contact pin, respectively. The tip element of the pressure contact pin is mechanically fixed and electrically connected to the sensor element 1, which is, for example, the same sensor element as described above. The mechanical and electrical connection between the tip element and the sensor element 1 can be established in the same way as described above.

[0081] The contact element 2 further comprises means 21 for a screw connection, namely an external thread 21 . 6 shows the location where an assembly of different components for an electronic device is provided. This assembly also comprises a substrate 6 and a power semiconductor device 3 mounted thereon. Furthermore, the assembly comprises a resin body 61 in which an auxiliary terminal (structure) 4 is partially embedded. The auxiliary terminal structure 4 protrudes from the right side of the resin body 61, and this protruding part forms a terminal area for the external electrical connection of the auxiliary terminal 4.

[0082] The further exposed part of the auxiliary terminal structure 4 is provided with means 41 for a screw connection, i.e. a through-hole with an internal thread, which is located vertically above the measuring surface 30 of the power semiconductor device 3.

[0083] FIG. 7 shows a further exemplary embodiment of an electronic device 100. Again, the electronic device 100 is a power semiconductor module 100. This power semiconductor module 100 is obtained by screwing the sensor unit 10 of FIG. 5 into the through-hole of the auxiliary terminal structure 4 of FIG. 6 . This positions the sensor element 1 on the measurement surface 30. The screwing further compresses the spring 22 of the contact element 2, causing the contact element 2 to be biased. As a result, the sensor element 1 is pressed against the measurement surface 30 by the biased contact element 2, thus forming a secure dry connection and dry electrical contact between the measurement surface 30 and the sensor element 1. The screw connection between the auxiliary terminal structure 4 and the contact element 2 secures the contact element 2 in a fixed position and in its biased state. A molding material 7, for example in the form of a gel, is then applied. The molding material 7 and the resin body 61 together form the housing body of the power semiconductor module 100. The sensor element 1 can be read out, for example, via the contact element 2 and the auxiliary terminal 4, as well as via a further terminal (for example a main terminal electrically connected to the measuring surface of the chip).

[0084] 8 shows a further exemplary embodiment of the sensor unit 10. In this case, the sensor unit 10 comprises two contact elements 2, each realized as a pressure contact pin. One contact element 2 is fixed and electrically connected to the top electrode 1a of the sensor element 1, and the other contact element 2 is fixed and electrically connected to the bottom electrode 1b. The sensor element 1 can therefore be read out via both contact elements 2. To enable contact of both the top electrode 1a and the bottom electrode 1b with the contact elements 2 from the top surface, the bottom electrode 1b protrudes laterally beyond the top electrode 1a, as shown in FIG. 8.

[0085] Alternatively, the sensor element 1 can be provided with two electrodes 1a and 1b on its top surface, so that the sensor element 1 can also be contacted with two contact elements 2 from the top surface.

[0086] 9 also shows a position where an assembly of several components 3, 6, 61, 62 is provided. Here, one component 62 is a circuit board, for example a PCB, mounted on a resin body 61 and laterally overlapping the power semiconductor device 3. The component 62 may be a control board and may include a control device.

[0087] 10, the sensor unit 10 of FIG. 8 is reattached with the sensor element 1 disposed on the measurement surface 30 of the power semiconductor device 3. The contact element 2 of the sensor unit 10 is screwed into a screw hole in the circuit board 62, thereby mechanically fixing the sensor element 1 to the circuit board 62 and mechanically biasing the sensor element 1 against the measurement surface 30.

[0088] 10 shows a further exemplary embodiment of an electronic device 100 in the form of a power semiconductor module 100. In this case, both contact elements 2 of the sensor unit 10 project vertically from the circuit board in such a way that the terminal areas of both contact elements 2 are exposed on the top side of the power semiconductor module 100. These terminal areas of the two contact elements 2 can be electrically connected for readout of the sensor element 1.

[0089] 11 shows the position where the assembly of substrate 6, power semiconductor device 3 and resin body 61 is provided. A hole is formed in the resin body 61 above the top metallization 6a, which in this case forms a measurement surface 60 where a physical quantity, for example temperature, is measured.

[0090] 12, the sensor unit 10 of FIG. 5 is attached by screwing it into the hole in the resin body 61 so that the sensor element 1 is again positioned on the measurement surface 60. To enable screwing, the hole in the resin body 61 may be provided with an internal thread. Alternatively, an internally threaded nut may be embedded in the resin body (not shown).

[0091] 13 shows an exemplary embodiment of an electronic device 100 that is a power semiconductor module 100. In this case, a thermally conductive material 5 in the form of a paste filled with electrically and / or thermally conductive particles, such as metal particles, or a flexible sheet of material, is placed between the sensor element 1 and the top electrode 3a. Dry electrical contact can be made between the material 5 and the sensor element 1 and / or between the material 5 and the top electrode 3a.

[0092] 13, the thermally conductive material 5 is also electrically conductive to establish electrical contact between the top electrode 3a and the sensor element 1. When such a thermally conductive material 5 is used in the exemplary embodiment of FIG. 10, the material 5 can be, for example, electrically insulating.

[0093] In the exemplary embodiment of the electronic device 100 of FIG. 14, the bottom surface of the sensor element 1, i.e., the bottom electrode 1a, includes a roughening having a plurality of protrusions and recesses. The average roughness of this roughening is, for example, at least 1.6 μm. When the sensor element 1 is pressed against the measurement surface 30 by the energized contact element 2, the protrusions imprint on the measurement surface 30, thereby improving the dry electrical contact, for example, by penetrating and / or locally destroying any oxide layer that may develop. For this purpose, the measurement surface 60 may be relatively soft compared to the material of the roughened surface.

[0094] 15 shows a position where a further exemplary embodiment of a sensor unit 10 for an electronic device is provided. In this case, the contact element 2 comprises a pressure-contact pin as described above and a terminal structure 24 mechanically and electrically connected to the pressure-contact pin. This connection can be established in various ways, for example by screwing, soldering, gluing, sintering, welding, etc. The terminal structure 24 is a sheet-like element and may be made of a metal, for example Cu or a Cu alloy.

[0095] In the position of FIG. 16, an assembly of different components for an electronic device 100 is again provided, comprising a substrate 6, a power semiconductor device 3 and a resin body 61.

[0096] Figure 17 shows an exemplary embodiment of an electronic device 100 in the form of a power semiconductor module 100 manufactured by, inter alia, attaching the sensor unit 10 of Figure 15 to the assembly of Figure 16. The auxiliary terminal structures 24 are, for example, glued to the resin body 61 so that the insulation displacement pins are maintained in a biased state. In Figure 17, the power semiconductor device 3 and a portion of the sensor unit 10 are embedded in a casting 7, for example in the form of a gel. The terminal structures 24 constitute auxiliary terminals of the power semiconductor module 100.

[0097] 18 shows in top view an exemplary embodiment of an electronic device 100 on a measurement surface 30. As can be seen, the sensor element 1 is positioned laterally on the measurement surface 30 between two adjacent bond wires, which are electrically and mechanically connected to the top electrodes 3 a of the power semiconductor devices 3.

[0098] FIG. 19 shows an exemplary embodiment of an electronic device 100 in the form of an assembly of two power semiconductor modules 8 mounted on a cooler 9. The cooler 9 is for cooling the power semiconductor modules 8. For example, the cooler 9 comprises channels for guiding a coolant through the cooler 9. The cooler 9 is formed of a metal, such as Cu or Al. The exposed surface of the cooler 9 serves as a measuring surface 90. A nut 91 having an internal thread is attached to the measuring surface 90. The sensor unit 10 of FIG. 5 is screwed onto the nut 91 so that the sensor element 1 is placed on the measuring surface 90 and the contact element 2 is fixed to the nut 91 in its biased state.

[0099] Instead of the cooler 9 forming the measurement surface, the base plate of the power semiconductor module may also form the measurement surface.

[0100] 1-19 represent exemplary embodiments and, therefore, do not constitute an exhaustive list of all embodiments of the improved sensor units, improved electronic devices, and improved methods. Actual sensor units, electronic devices, and methods may differ from the illustrated embodiments, for example, in terms of arrangement, devices, and elements. [Explanation of symbols]

[0101] Reference sign 1 Sensor element 1a Top electrode 1b Bottom electrode 2 Contact Elements 3 Power semiconductor devices 3a Top electrode 4 Auxiliary terminal (structure) 5. Thermally conductive materials 6 PCB 6a Top Metallization 7 Casting / Gel 8 Power Semiconductor Modules 9 Cooler 10. Sensor unit for electronic devices 21 Means for threaded connections 22 Spring 24 Auxiliary terminal structure 30 Measurement surface 41 Means for threaded connections 60 Measurement Surface 61 Resin / Resin body / Housing frame 62 Circuit Board 90 Measuring surface 91 Nut 100 Electronic Devices

Claims

1. A sensor unit (10) for an electronic device (100), comprising: - a sensor element (1) for measuring a physical quantity within said electronic device (100); a contact element (2) configured to be mechanically biased, - said contact element (2) comprises a pressure contact pin, - said contact element (2) is fixed to and electrically connected to said sensor element (1); - The sensor unit (10) is configured to be attached to the member (3, 6, 9) of the electronic device (100) by placing the sensor element (1) on a measurement surface (30, 60, 90) of the member (3, 6, 9) and mechanically biasing the contact element (2) so that the mechanically biased contact element (2) applies a force to the sensor element (1) acting in a direction toward the measurement surface (30, 60, 90).

2. - said sensor element (1) is a temperature sensor; The sensor unit (10) according to claim 1.

3. - said contact element (2) comprises a spring contact; A sensor unit (10) according to claim 1 or 2.

4. - said contact element (2) is fixed to said sensor element (1) by a material locking connection; A sensor unit (10) according to any one of the preceding claims.

5. - said contact element (2) comprises means (21) for screwing said contact element (2) into a thread of said electronic device (100); A sensor unit (10) according to any one of the preceding claims.

6. - the sensor element (1) comprises a top electrode (1a) on a top surface of the sensor element (1) and a bottom electrode (1b) on a bottom surface of the sensor element (1) opposite to the top surface; - said contact element (2) is fixed and electrically connected to said top electrode (1a) of said sensor element (1); - the bottom electrode (1b) of the sensor element (1) is exposed in the configuration in which the sensor unit (10) is not attached; A sensor unit (10) according to any one of the preceding claims.

7. An electronic device (100), comprising: - a sensor unit (10) according to any one of the preceding claims, a member (3, 6, 9) having a measuring surface (30, 60, 90) on which a physical quantity is measured by means of said sensor element (1), - said sensor element (1) is arranged on said measuring surface (30, 60, 90), - an electronic device (100), wherein said contact element (2) is mechanically biased to apply a force to said sensor element (1) acting in a direction towards said measuring surface (30, 60, 90);

8. - comprising a power semiconductor device (3), - the sensor element (1) is arranged on the power semiconductor device (3), The electronic device (100) of claim 7.

9. - the measuring surface (30) is formed by the top electrode (3a) of the power semiconductor device (3), - the sensor unit (10) is a sensor unit (10) according to claim 6, - the bottom electrode (1b) of the sensor element (1) is in dry electrical contact with the top electrode (3a) of the power semiconductor device (3); The electronic device (100) of claim 8.

10. - said contact elements (2) are electrically and mechanically connected to auxiliary terminals (4) of said electronic device (100); An electronic device (100) according to any one of claims 7 to 9.

11. - said contact element (2) is fixed to an electrically insulating element of said electronic device (100); An electronic device (100) according to any one of claims 7 to 9.

12. - a part of said contact element (2) is exposed and constitutes a terminal area of ​​said contact element (2) for external electrical connection of said contact element (2); An electronic device (100) according to any one of claims 7 to 11.

13. a thermally conductive material (5) is arranged between said measuring surface (30, 60, 90) and said sensor element (1); - said thermally conductive material (5) comprises a paste filled with conductive particles; An electronic device (100) according to any one of claims 7 to 12.

14. - at least one power semiconductor module (8) and a cooler (9) for said at least one power semiconductor module (8), - said measuring surface (90) is formed by said cooler (9), An electronic device (100) according to any one of claims 7 to 13.

15. - at least one of the measuring surface (30, 60, 90) and the surface of the sensor element (1) facing the measuring surface (30, 60, 90) is roughened in order to increase the contact surface, - said rough surface has an average roughness of at least 1.6 μm; An electronic device (100) according to any one of claims 7 to 14.

16. 1. A method of attaching a sensor element, comprising: - providing a sensor unit (10) according to any one of claims 1 to 6, - providing a component (3, 6, 9) for an electronic device (100) having a measuring surface (30, 60, 90) on which a physical quantity of said electronic device (100) is measured using said sensor element (1); - attaching said sensor unit (10) to said member (3, 6, 9), - placing said sensor element (1) on said measuring surface (30, 60, 90); - mechanically biasing the contact element (2) so as to exert a force on the sensor element (1) acting in a direction towards the measuring surface (30, 60, 90); - fixing at least a part of said mechanically biased contact element (2) relative to said member (3, 6, 9) so that said contact element (2) remains mechanically biased; and A method comprising:

17. - fixing at least a part of the mechanically biased contact element (2) to the member (3, 6, 9) comprises screwing the contact element (2) into a thread of the electronic device (100); 17. The method of claim 16.

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