Sensor assembly

Abstract

The invention relates to a sensor assembly for sensing physical properties in a first environment, in particular humidity and / or pressure and / or temperature. The sensor assembly comprises a sensor mounting body, a sensing device (105) for sensing a physical property, and a plurality of electrical connection pins. The sensor mounting body comprises a first side (113) for interfacing the first environment (101). The sensing device is arranged over the first side (113), wherein the sensing device comprises an integrated circuit (IC) sensor chip and a package for the IC sensor chip. Each of the plurality of electrical connection pins extends through the sensor mounting body from a first side of the sensor mounting body to a second side (115) of the sensor mounting body. A passage through the sensor mounting body of each of the electrical connection pins is sealed by a sealing portion made of a sealing material. Each of the electrical connection pins is directly attached to a package (127) of the sensing device (105).

Description

TECHNICAL FIELD

[0001] The present invention relates to a sensor assembly for sensing a physical property, in particular humidity and / or pressure and / or temperature, in a first environment. BACKGROUND

[0002] It is known to implement sensing devices for sensing a physical property in a given environment. In some particular harsh environments, such as high pressure environments, high temperature environments, high vibration environments, liquid immersion environments or high volume flux environments, some electronic parts of the sensing device required for data processing and / or signaling can not be sufficiently robust. In these cases, usually only the sensing element sensitive to the physical property in the given environment is left while the electronic parts are moved to a different, less challenging environment. For example, US 2015 / 241293 A1 discloses a pressure sensor with a front seal, wherein only a separate pressure sensing element is provided in the environment to be sensed.

[0003] This separation of the electronic parts and the sensing part of the sensing device increases the manufacturing complexity and reduces the sensing quality due to additional disturbing factors. SUMMARY

[0004] It is therefore an object of the present invention to provide an improved sensing solution for sensing harsh environments, in particular with improved accuracy and reduced manufacturing costs.

[0005] This object is achieved by a sensor assembly for sensing a physical property, in particular humidity and / or pressure and / or temperature, in a first environment as defined in claim 1. The sensor assembly comprises a sensor mounting body, a sensing device for sensing the physical property, and a plurality of electrical connection pins. The sensor mounting body comprises a first side for interfacing the first environment. The sensing device is arranged on the first side. The sensing device comprises an integrated circuit (IC) sensor chip and a package for the IC sensor chip. Each of the electrical connection pins extends from the first side of the sensor mounting body through the sensor mounting body to a second side. The passage of each of the electrical connection pins through the sensor mounting body is sealed by a sealing portion made of a sealing material. Each of the electrical connection pins is directly attached to the package of the sensing device.

[0006] The sensor assembly of the present invention allows for the arrangement of the IC sensor chip in the first environment and thus provides a more cost-efficient solution for sensing harsh environments while providing increased accuracy. In particular, the direct attachment of the package of the sensing device to the electrical connection pins without interconnecting a printed circuit board or other intermediate connection means ensures manufacturing cost efficiency while also reducing the exposure to the harsh environment to be sensed. At the same time, the sealing portion sealing the passage of the electrical connection pins can guarantee the sealing performance of the sensor assembly when mounted in the first environment.

[0007] In some aspects, the sensing device, in particular the package, can be attached to the sensor mounting body only via direct attachment to each of the electrical connection pins. This provides a particularly light and fast to manufacture sensing solution.

[0008] In some aspects, the sensing device, in particular the package, can be attached to the sensor mounting body via a support structure interposed between the package and the sensor mounting body. Thus, the structural, i.e. mechanical, attachment of the sensing device is strengthened, providing greater resistance to vibrations than in the absence of the support structure. Moreover, advantageously, the support structure can be positioned in contact with the thermal pad of the package of the sensing device, thereby acting as a heat sink.

[0009] In some aspects, the first environment can be a liquid immersion environment, such as an oil immersion environment, for example a brake oil immersion environment. In some aspects, the first environment can be an environment having an environmental pressure greater than 100 kPa (1 bar), in particular greater than 1 Mpa (10 bar), preferably greater than 5 MPa (50 bar), wherein the package is suitable for the first environment. In some aspects, the first environment can be an environment having an environmental temperature greater than 100 °C, in particular greater than 120 °C, preferably greater than 140 °C. The IC sensor chip can provide increased sensing accuracy and durability for these harsh environments.

[0010] In some aspects, the package can be a flat leadless package, preferably a dual flat no-lead (DFN) or quad flat no-lead (QFN) package. Such a package can be particularly suitable for sensing in harsh environments, as the leadframe connections to the IC sensor chip are more protected and durable than some contact arrangements of alternative IC package types.

[0011] In some aspects, each of the plurality of connection pins can comprise a pin terminal, in particular a flat pin terminal or a bent pin terminal or a stepped pin terminal. Flat pin terminals can provide for faster and more stable assembly. Bent pin terminals can be less damaging to the IC sensor chip package contact pads. Stepped pin terminals can facilitate press-fit assembly, in particular manual press-fit assembly, of the IC sensor chip package with the electrical connection pins.

[0012] In some aspects, the package, in particular the leadframe of the package, can be directly attached to each of the pin terminals, such that electrical connection with the IC sensor chip is achieved. Thus, further electronic components can be in communication with the IC sensor chip via the electrical connection pins.

[0013] In some aspects, each of the pin terminals can comprise a soldered or welded portion attached to the package, in particular to a respective contact pad of the package. The package can be attached to the pin terminals by soldering or welding, in particular the soldered or welded portions. Soldering or welding provides greater resistance to vibrations and lower electrical contact resistance for the electrical connections between the pins and the sensing device.

[0014] In some aspects, the package can be attached to the pin terminals by press fitting. Press fitting provides faster and / or more cost-effective manufacturing than soldering or welding.

[0015] In some aspects, the sensor mounting body can comprise, in particular be made of, a metal, preferably stainless steel. In some aspects, the sealing material can be a different material than the material of the sensor mounting body. In some aspects, the sealing material can comprise or be made of an inorganic material, in particular a ceramic, preferably glass. Glass can provide good sealing properties required for harsh environments, in particular when sealed to a metallic sensor mounting body. In some aspects, the sealing material can comprise or be made of an organic polymer, preferably an epoxy or a polyphenylene sulfide (PPS) or a polyether urethane. These can provide sufficient sealing properties while being more cost-effective to implement than ceramic sealing materials, in particular glass.

[0016] In some aspects, the sensor mounting body can be configured to be mounted in a passage between a first environment and a second environment, thereby sealing the passage. Thus, the sensor assembly allows mounting the sensing device in the first environment while allowing access to the sensing device from a different second environment, e.g. from an ambient environment outside the first environment.

[0017] In some aspects, the sensor mounting body can comprise an externally threaded portion, and the sensor mounting body can be configured to be screwed into the passage via the externally threaded portion. Screwing provides sealing while being reversible, thereby providing improved maintenance and repair properties.

[0018] In some aspects, the plurality of connection pins can comprise at least three, in particular at least four, preferably exactly four connection pins. Three electrical pins can be sufficient to control an IC sensor chip. Four electrical pins are particularly suitable for electrical connection with an IC sensor chip, e.g. by allocating two electrical connection pins to signaling and two electrical connection pins to power supply.

[0019] In some aspects, each of the connection pins can be sealed by a respective sealing portion made of the sealing material through the passage of the sensor mounting body. Thus, the amount of sealing material required is reduced, also reducing manufacturing costs.

[0020] In some aspects, each of the connection pins can be sealed by a single continuous sealing portion made of a sealing material through the passage of the sensor mounting body. Such a construction can require fewer manufacturing steps and thus can be less prone to sealing defects.

[0021] In some aspects, the sealing portion can extend beyond the sensor mounting body to at least partially, preferably completely, encapsulate the package. Such a construction further enhances the robustness of the sensor assembly and thus prolongs the sensor assembly lifetime. BRIEF DESCRIPTION OF DRAWINGS

[0022] The above aspects, objects, features and advantages of the present application will be more fully appreciated as the same becomes better understood by reference to the following more detailed description of the presently preferred, exemplary embodiments of the application when considered in connection with the accompanying drawings, in which:

[0023] Figure 1 A sensor assembly according to a first embodiment of the application is illustrated.

[0024] Figure 2 A view of the attachment of the package for an IC sensor according to a variant of the first embodiment is shown.

[0025] Figure 3 A view of the attachment of the package for an IC sensor according to a variant of the first embodiment is shown.

[0026] Figure 4 A sensor assembly according to a second embodiment of the application is illustrated.

[0027] Figure 5 A sensor assembly according to a third embodiment of the application is illustrated. DETAILED DESCRIPTION

[0028] Unless specifically described otherwise, the structural features of the objects shown in the drawings are not drawn to scale, neither individually with respect to their Cartesian dimensions, nor with respect to each other along one Cartesian direction. Furthermore, the same reference signs used repeatedly in different drawings refer to the same elements. Figures 1 to 5

[0029] The technical features described below and their associated advantages or effects can be combined together or applied to any aspect or embodiment of the application, independently, so as to generate further possible embodiments or aspects of the application.

[0030] Figure 1 A cross-sectional view of a sensor assembly according to a first embodiment of the application is shown. Figure 1 ​The sensor assembly 100 shown above is a sensor assembly for sensing a physical property of a first environment 101, in particular humidity and / or pressure and / or temperature. The sensor assembly comprises a sensor mounting body 103, a sensing member 105 for sensing the physical property in the first environment 101, and a plurality of electrical connection pins 107. In particular, the sensor assembly 100 comprises four electrical connection pins 107, of which only two 107a, 107b are visible on the sectional view. Figure 1

[0031] In the present embodiment, the sensor mounting body 103 is substantially rotationally symmetrical with respect to a central axis 109. Along an extension direction 111 coaxial with the central axis 109, the sensor mounting body 103 comprises a first side 113, a second side 115, and an intermediate portion 117. The intermediate portion 117 is interposed between and mechanically connects the first side 113 and the second side 115, such that the first side 113 is opposite the second side 115 with respect to the intermediate portion 117.

[0032] The first side 113 is configured to interface with the first environment 101, and the second side 115 is configured to interface with a second environment 119a different from the first environment 101. The sensor mounting body 103 is configured to be mounted in a passage 119 or opening between the first environment 101 and the second environment 119a. For example, the first environment 101 is the environment to be sensed, and the second environment 119a is the ambient environment, and the passage 119b is a hole in an internal wall 119c separating the first environment 101 and the second environment 119a.

[0033] In particular, here, the intermediate portion 117 comprises an externally threaded portion 121. Thus, the sensor mounting body 103 is configured to be screwed into said passage 119b, for example, wherein the passage 119b is configured as a nut and / or comprises an internal thread matching the externally threaded portion 121. In particular, the sensor mounting body 103 can be configured to seal the passage 119b, in particular when screwed into said passage 119b. Optionally, the sensor mounting body 103 can further comprise a groove 121 b for positioning a sealing joint, such as an O-ring.

[0034] ​In the present embodiment, the first environment 101 can be a liquid immersion environment, for example a brake oil immersion environment. However, the sensor assembly 100 is also suitable for sensing in other environments, in particular harsh environments, such as high pressure environments and / or high temperature environments. A high pressure environment can be an environment having an ambient pressure of more than 100 kPa (1 bar), or more than 1 MPa (10 bar), or more than 1.5 MPa (15 bar), or more than 2 MPa (20 bar), or more than 2.5 MPa (25 bar), or more than 3 MPa (30 bar), or more than 5 MPa (50 bar), or more than 6 MPa (60 bar). A high temperature environment can be an environment having an ambient temperature of more than 100 °C or more than 120 °C or more than 140 °C.

[0035] The sensor mounting body 103 comprises metal, in particular here stainless steel. In particular, the entire sensor mounting body 103 can be made of metal, in particular stainless steel. For example, the sensor mounting body 103 can be integrally molded from stainless steel.

[0036] In some variants, the sensor mounting body can instead comprise a body made of glass fiber reinforced polybutylene terephthalate (PBT) or glass fiber reinforced polyamide (PA) (e.g. PBT-GF30 or PA-66-GF30), and the externally threaded portion can be an overmolded machined threaded screw.

[0037] The sensing member 105 is arranged above the first side 113 of the sensor mounting body 103. In particular, the first side 113 of the sensor mounting body 103 comprises a shroud 123 which tubularly extends in a direction opposite to the extension direction 111 around the central axis 109 to enclose the sensing device 105. The shroud 123 comprises a plurality of through-holes 125. The through-holes 125 facilitate the interfacing, i.e. direct contact, of the sensing device 105 with the first environment 101. At the same time, the shroud 123 protects the sensing device 105 from high volume flux in the ambient fluid (e.g. collisions with large particles) or from mechanical impact (e.g. from accidental handling).

[0038] The sensing device 105 comprises Figure 1The package 127 encapsulates an invisible integrated circuit (IC) sensor chip and a package for the IC sensor chip. Here, the IC sensor chip is an application-specific integrated circuit (ASIC) that includes a sensing layer sensitive to changes in the physical properties of the first environment 101 to be sensed. For example, the sensing layer may be sensitive to humidity, i.e., moisture. Therefore, in an example where the first environment 101 is a brake fluid immersion environment, the sensing device 105 can be configured to sense the water content in the brake fluid. The package 127 encapsulates, i.e., holds, the IC sensor chip. Specifically, the package 127 encapsulates the IC sensor chip such that the sensor chip is protected from destructive environmental interference, but does not prevent or interfere with the sensing of physical properties or the outward signaling, for example, via electrical connection pins 107.

[0039] like Figure 1 As shown, electrical connection pins 107 extend through the sensor mounting body 103, particularly through the intermediate portion 117. The electrical connection pins 107 extend from the first environment 101 to the second environment 119a along the extension direction 111, preferably parallel to the central axis 109. Specifically, each of the electrical connection pins 107 extends through a corresponding channel 129 formed in the sensor mounting body 103. Figure 1 In the cross-sectional view, only channels 129a and 129b for electrical connection pins 107a and 107b are visible. Electrical connection pin 107a extends through channel 129a, and electrical connection pin 107b extends through channel 129b. Therefore, the corresponding channels 129a and 129b also extend along the extension direction 111 and parallel to the central axis 109.

[0040] Each of the electrical connection pins 107 has its channel 129 through the sensor mounting body 103 sealed by a corresponding sealing portion 131. For example, in Figure 1 In the cross-sectional view, the channel 129a for the electrical connection pin 107a is sealed by the sealing portion 131a, and the channel 129b for the electrical connection pin 107b is sealed by the corresponding sealing portion 131b.

[0041] The corresponding sealing portion 131 may include a sealing material configured to fill, in particular, completely and permanently fill, the remaining space in the channel 129 that holds the corresponding electrical connection pin 109. For example, the corresponding sealing portion 131 may be made entirely of the sealing material to improve sealing performance. Here, the corresponding sealing portion 131 is made of glass. Preferably, the glass sealing portion 131 is bonded to the metal sensor mounting body 103 and the electrical connection pin 107 via a glass-metal bonding process. Thus, the sensor mounting body 103 can be implemented as a glass-metal (GTM) screw.

[0042] In alternative embodiments, particularly where cost is more important than sealing performance, sealing portions 131a, 131b may comprise and / or be made of a ceramic different from glass, instead of glass. Alternatively, sealing portions 131a, 131b may also comprise and / or be made of an organic polymer, such as epoxy resin, polyether urethane, or polyphenylene sulfide (PPS).

[0043] Figure 1 In the sensor assembly 100 of the first embodiment, the sensing device 105 is directly attached to the electrical connection pin 107. Specifically, the package 127 is directly soldered to the electrical connection pin 107. More specifically, each of the electrical connection pins 107 includes a pin terminal 133, and each pin terminal 133 is soldered to a contact pad 135 of the package 127, which is configured to perform signaling and / or power supply using the IC sensor held in the package 127.

[0044] like Figure 1 As shown, electrical connection pin 107a includes a pin terminal 133a soldered to contact piece 135a of package 127, and electrical connection pin 107b includes a pin terminal 133b soldered to contact piece 135b of package 127. In some variations, pin terminal 133 may be fused to contact piece 135 instead of soldered.

[0045] According to a first embodiment of the invention, the sensing device 105, particularly the package 127, is attached to the sensor mounting body 103 only via a plurality of electrical connection pins 107. That is, the electrical connection pins 107 soldered to the package 127 are the only mechanical link and / or structural attachment between the sensing device 105 and the sensor mounting body 103. This configuration further reduces the number of individual components and manufacturing steps required for the sensor assembly, thereby reducing the risk of signal interference and / or manufacturing defects.

[0046] Once connected to another electrical component, the electrical connection pin 107 establishes an electrical signal and / or powers the IC sensor chip included in the package 127 of the sensing device 105. Specifically, the electrical connection pin 107 enables an electrical connection between the sensing device 105 disposed on the first side 113 of the sensor mounting body 101 and another electrical component disposed on or in the second side 115 of the sensor mounting body 101.

[0047] Figure 1The further electrical component, not shown, can be a control unit, a processor unit and / or an antenna. The further electrical component is configured to control and / or process data of the IC sensor chip of the sensing device 105 and / or to store data of the IC sensor chip of the sensing device 105. Preferably, the further electrical component comprises a printed circuit board (PCB) comprising one or more processors, and / or one or more antennas, and / or an electrical connection structure configured to cooperate with an electrical connector. In some variants, the further electrical component can for example be only an electrical connection structure configured to cooperate and de-cooperate with a dedicated mating connector for wiring the IC sensor chip to a desired location. In some variants, the further electrical component can be an Internet of Things (IoT) wireless system, preferably a LoRa wireless system or a BLE wireless system.

[0048] The electrical connection pins 107 can be made of a nickel-iron alloy, here Invar due to the similarity of the coefficient of thermal expansion (CTE), thereby providing an improved thermal expansion synergy with the glass sealing portion 131. In variants, the electrical connection pins 107 can also be made of a nickel-cobalt alloy such as Kovar or a tin alloy or a brass alloy.

[0049] The electrical connection pins 107 can be cylindrical and metal-plated. In particular, the pin terminals 133 can comprise a metal plating to reduce corrosion. Preferably, the metal plating of the electrical connection pins 107, in particular of the pin terminals 133, comprises a first nickel plating directly on the Invar alloy connection pins 107, then additionally a second gold plating on top of the nickel layer for improving the soldering-related corrosion resistance properties. In some variants, the electrical connection pins can be cuboid (instead of cylindrical) to prevent the pins from twisting before the sealing passage.

[0050] The sealing passages 129 through which the electrical connection pins 107 extend can each have the same length 137 (i.e. extent along the extension direction 111) and the same diameter 139 (i.e. extent along a direction orthogonal to the extension direction 111). The length 137 of the sealing passages 129 can be greater than 5 times, preferably greater than 10 times, the diameter 139 of the sealing passages 129. In this configuration, the sealing performance of the sensor assembly 100 is improved compared to a shorter length 139, while the second environment 119a is reliably sealed off from the first environment 101.

[0051] The package 127 of the sensing device 105 can be a flat, leadless package for an integrated circuit, also known as a microleadframe package or a small outline leadless package. In this case, the package 127 does not include any externally protruding lead contacts for contacting the integrated circuit in the package. Specifically, the package 127 is preferably a dual flat, leadless (DFN) package, or alternatively a quad flat, leadless (QF) package. These package types provide satisfactory durability even in harsh environments. However, in some variations, alternative package types can be applied to the sensing device 105, such as flip-chip or planar grid array (LGA) packages.

[0052] According to a first embodiment of the invention, each pin terminal 133 of the contact piece 135 for attachment to the sensing device 105 is flat. That is, each pin 107 is sheeted to provide a radially flat pin terminal 133 orthogonal to the extension direction 111. The flat terminal 133 of the first embodiment can provide a plane for the sensing device 105 during manufacturing and thus provide a more stable positioning plane.

[0053] Figure 2 The attachment of a sensing device 105 according to a variation of the first embodiment is shown. Figure 2 In a variation, the electrical connection pins 207 of the corresponding sensor assembly include different pin terminals 233. The pin terminals 233 are not flat and / or radially sheet-like, but instead include bends 241. That is, the pin terminals 233 are bent relative to the extension direction 111. Preferably, each of the bent pin terminals 233 is bent at an angle 245 between 80° and 100°, preferably 90°. In the variation, the bent pin terminals 233 are bent inward relative to each other, particularly towards a common center point. Compared to the flat pin terminal 133 configuration, this configuration of the pin terminals 233 provides more surface area for soldering and also reduces the risk of wear during positioning and manufacturing due to the smaller angled edges.

[0054] Figure 3 The attachment of a sensing device 105 according to another variation of the first embodiment is shown. Figure 3 In a variant, the electrical connection pins 307 of the corresponding sensor assembly include alternative pin terminals 333. Here, each pin terminal 333 includes a stepped shape 341. That is, the stepped shape 341 is machined into the end of each corresponding electrical connection pin 307. Here, the stepped shape 341 is substantially L-shaped and is configured to provide mechanical support for the package 127.

[0055] according to Figure 3A variant of this variant, the electrical connection pins 307 can be attached to the package 127 by a press-fit arrangement. The electrical connection pins 307 each comprise a respective step shape 341 and are positioned relative to each other such that a press-fit attachment, i.e. a friction fit, of the package 127 can be achieved when the package 127 is pressed into the slot formed by the four step shapes 341 of the pin terminals 333 along the extension direction 111. Optionally, the press-fit package 127 can be additionally soldered to the pin terminals 333 and the step shapes 341 of the pin terminals 333 allow for a faster and more convenient soldering due to their centering and support function.

[0056] This variant offers the advantage of eliminating manufacturing steps such as soldering or welding that can be erosive to the electrical connection pins 107 and also avoids possible contamination of the functionality of the sensor assembly 100 by the bonding material.

[0057] Figure 4 A partial view of a sensor assembly 400 according to a second embodiment of the present application is shown. The sensor assembly 400 of the second embodiment differs from the sensor assembly 100 of the first embodiment in that it further comprises a support unit 443. The support unit 443 comprises a support housing 445 and a columnar support structure 447. The support housing 445 can be a plastic shroud around the sensing device 105 and protects the sensing device 105 from external damage in a similar manner as the shroud 123 of the first embodiment.

[0058] The support structure 447 is preferably made of the same material as the support housing 445 and is centrally arranged on the sensor mounting body 103, protruding along the central axis towards the first side 113. In particular, the support structure 447 is interposed between the sensing device 105, in particular the package 127, and the sensor mounting body 103. The support structure 447 serves as an additional mechanical support for the sensing device 105, in particular before attachment to the electrical connection pins 107, thereby reducing mechanical strain on said electrical connection pins 107. In addition, the support structure 447 can be shaped to provide a centering function for the package 127 before attachment to the electrical connection pins 107.

[0059] In one variant of the second embodiment, the support structure 447 can comprise attachment means for attachment with the sensing device 105. Thus, the attachment of the sensing device 105 to the support structure 447 can complement and reinforce the attachment of the sensing device 105 to the electrical connection pins 107.

[0060] In another variant of the second embodiment, the support structure 447 can be configured as a heat sink. For example, when the package 127 of the sensing device 105 comprises an exposed heat pad for facilitating heat exchange of an IC sensor wafer held in the package 127, the support structure 447 can be arranged in direct contact with said heat pad. In this variant, the support structure 447 is preferably formed of metal, preferably of the same metal as said heat pad. Thus, heat dissipation of the sensing device 105 can be improved.

[0061] Figure 5 A partial view of a sensor assembly 500 according to a third embodiment of the present application is shown. The sensor assembly 500 differs from the sensor assembly of the first embodiment in that the sensing device 105 and the four electrical connection pins 107 are enclosed in a sealed substrate 549, to which the sensing device 105, in particular the package 127, is attached to establish electrical connections. The sealed substrate 549 comprising the four electrical connection pins 107 and the sensing device 105 is arranged in an enlarged channel 529 extending coaxially along the central axis 109. Thus, the substrate extension 549 extends beyond the sensor mounting body 503, still enclosing the entire sensing device 105.

[0062] The enlarged channel 529 is sealed by a sealing portion 531, which is composed of a sealing material different from the material of the sensor mounting body 503. By way of example, as known from the first embodiment, the sensor mounting body 503 comprising the single enlarged channel 529 can be made of steel, and the sealing portion 531 can be made of glass, and the substrate 549 holding the sensing member 105 can be made of an epoxy material with glass filler. In a variant, the substrate 549 and the sealing portion 531 can be made of the same material, and preferably are a single continuous portion.

[0063] As Figure 5 shown, the sensing device 105 can be arranged in the substrate 549 such that the package 127 extends vertically with respect to the central axis 109, instead of horizontally. Thus, all four electrical connection pins 107 can be arranged in the same plane parallel to the central axis 109, and thus the substrate 549 can advantageously be formed thin and compact. Generally, due to the implementation of a pre-assembled substrate, Figure 5 The third embodiment allows for even more cost-effective manufacturing.

[0064] The described embodiments relate to a sensor assembly of the invention having exactly four electrical connection pins. However, in a variant, the sensor assembly can instead include only three electrical connection pins when using a sensing device that only requires three electrical connections. In a further variant, the sensor assembly can instead include more than four (e.g. six or eight) electrical connection pins. For example, when the sensor assembly includes eight electrical connection pins, two sensing devices 105 can be implemented in the sensor assembly.

[0065] The described embodiments relate to a sensor assembly of the invention in which the sensing device 105 includes one integrated circuit (IC) sensor chip and one package 127 for the IC sensor chip. However, in a variant of the invention, the sensing device can also include multiple (e.g. two or three) IC sensor chips held in a corresponding plurality of packages. Each of the plurality of packages is thus arranged on the sensor mounting body and attached to a corresponding number of electrical connection pins extending through the sensor mounting body, such as the electrical connection pins 107 extending through the sensor mounting body 103.

[0066] In other variants of the invention, the sensing device can include one or more additional sensing elements that are not part of an IC sensor chip in addition to one or more IC sensor chips. For example, the sensing device can include the package 127 holding the IC sensor chip, and a separate non-IC based sensing element configured to sense a physical property. By way of example, the non-IC based sensing element can be a flexural piezoelectric resonator configured to sense temperature and / or liquid viscosity and / or liquid density, the resonator having two poles attached to respective electrical connection pins extending through the sensor mounting body, such as the electrical connection pins 107 extending through the sensor mounting body 103.

[0067] The sensor assemblies 100, 400, 500 described herein, and the variants thereof outlined above, achieve the invention by providing a sensing solution for harsh environments that provides improved durability, accuracy, and manufacturing cost efficiency.

[0068] Reference Signs

[0069] 100 sensor assembly

[0070] 101 first environment

[0071] 103 sensor mounting body

[0072] 105 sensing device

[0073] 107, 107a, 107b, electrical connection pin

[0074] 109 central axis

[0075] 111 extension direction

[0076] 113 first side

[0077] 115 second side

[0078] 117 intermediate portion

[0079] 119a second environment

[0080] 119b passage between the first and second environments

[0081] 119c inner wall

[0082] 121 externally threaded portion

[0083] 121b groove for sealing joint

[0084] 123 shroud

[0085] 125 through hole in shroud

[0086] 127 package for IC sensor chip

[0087] 129, 129a, 129b channel

[0088] 131, 131a, 131b sealing portion

[0089] 133, 133a, 133b pin terminal

[0090] 135, 135a, 135b contact tab

[0091] 137 length of channel

[0092] 139 diameter of channel

[0093] 207 electrically connecting pin

[0094] 233 pin terminal

[0095] 241 bend

[0096] 245 bend angle

[0097] 307 electrically connecting pin

[0098] 333 pin terminal

[0099] 341 step shape

[0100] 400 sensor assembly

[0101] 443 support unit

[0102] 445 support housing

[0103] 447 support structure

[0104] 500 sensor assembly

[0105] 503 sensor mounting body

[0106] 529 enlarged passage

[0107] 531 sealing portion

[0108] 549 substrate

Claims

1. A sensor assembly for sensing physical properties, particularly humidity and / or pressure and / or temperature, in a first environment (101), said sensor assembly (100, 400, 500) comprising a sensor mounting body (103, 503), a sensing device (105) for sensing said physical properties, and a plurality of electrical connection pins (107, 107a, 107b, 207, 307). in, The sensor mounting body (103, 503) includes a first side (113) for docking with the first environment (101), and the sensing device (105) is arranged on the first side (113). The sensing device (105) includes an integrated circuit (IC) sensor chip and a package (127) for the IC sensor chip. Each of the electrical connection pins (107, 107a, 107b, 207, 307) extends from the first side (113) of the sensor mounting body (103, 503) through the sensor mounting body (103, 503) to the second side (115), wherein the channel (129, 129a, 129b, 529) through the sensor mounting body (103, 503) of each of the electrical connection pins (107, 107a, 107b, 207, 307) is sealed by a sealing portion (131, 131a, 131b, 531) made of sealing material. Each of the electrical connection pins (107, 107a, 107b, 207, 307) is directly attached to the package (127) of the sensing device (105).

2. The sensor assembly according to claim 1, wherein, The sensing device (105), and in particular the package (127), is attached to the sensor mounting body (103, 503) only via direct attachment to each of the electrical connection pins (107, 107a, 107b, 207, 307).

3. The sensor assembly according to claim 1, wherein, The sensing device (105), in particular the package (127), is also attached to the sensor mounting body (103) via a support structure (447) placed between the package (127) and the sensor mounting body (103).

4. The sensor assembly according to any one of claims 1 to 3, wherein, The first environment (101) is a liquid immersion environment, such as an oil immersion environment, or an environment with an environmental pressure greater than 100 kPa, particularly greater than 1 MPa, preferably greater than 5 MPa, wherein the package (127) is suitable for the first environment (101).

5. The sensor assembly according to any one of claims 1 to 4, wherein, The package (127) is a flat leadless package, preferably a dual flat leadless (DFN) or quad flat leadless (QFN) package.

6. The sensor assembly according to any one of claims 1 to 5, wherein, Each of the electrical connection pins (107, 107a, 107b, 207, 307) includes a pin terminal (133, 133a, 133b, 233, 333), particularly a flat pin terminal (133, 133a, 133b) or a bent pin terminal (233) or a stepped pin terminal (333), and the lead frame of the package (127), particularly the package (127), is directly attached to each of the pin terminals (133, 133a, 133b, 233, 333), thereby enabling an electrical connection with the IC sensor chip.

7. The sensor assembly according to any one of claims 1 to 6, wherein, Each of the pin terminals (133, 133a, 133b, 233) includes a soldered or fused portion attached to the package (127), and in particular to the corresponding contact (135, 135a, 135b) of the package (127).

8. The sensor assembly according to any one of claims 1 to 6, wherein, The package (127) is attached to the pin terminal (333) by form-fitting.

9. The sensor assembly according to any one of claims 1 to 8, wherein, The sensor mounting body (103, 503) comprises metal, particularly made of metal, preferably stainless steel.

10. The sensor assembly according to any one of claims 1 to 9, wherein, The sealing material is glass or epoxy resin.

11. The sensor assembly according to any one of claims 1 to 10, wherein, The sensor mounting bodies (103, 503) are configured to be installed in a passage between the first environment (101) and the second environment (119) to seal the passage. In particular, the sensor mounting bodies (103, 503) include an external threaded portion (121), and the sensor mounting bodies (103, 503) are configured to be screwed into the passage via the external threaded portion (121).

12. The sensor assembly according to any one of claims 1 to 11, wherein, The plurality of electrical connection pins (107, 107a, 107b, 207, 307) include at least three, particularly at least four, and preferably exactly four electrical connection pins (107, 107a, 107b, 207, 307).

13. The sensor assembly according to any one of claims 1 to 12, wherein, Each of the electrical connection pins (107, 107a, 107b, 207, 307) is sealed by a corresponding sealing portion (131, 131a, 131b) made of sealing material through a channel passing through the sensor mounting body (103, 503).

14. The sensor assembly according to any one of claims 1 to 12, wherein, Each of the electrical connection pins (107, 107a, 107b, 207, 307) passes through the channel (529) of the sensor mounting body (503) and is sealed by a single continuous sealing portion (531) made of sealing material.

15. The sensor assembly of claim 14, wherein, The sealing portion (531) extends beyond the sensor mounting body (503) to at least partially, and preferably completely, enclose the package (127).

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