Sensor device, method for manufacturing a sensor device, and method for operating a sensor device

Abstract

This invention relates to a sensor device comprising: at least one first substrate (20) having a first substrate surface (20a); a sensor element layer (22) having at least one sensitive element disposed in a sensor element layer (22), wherein the sensor element layer (22) covers the first substrate surface (20a) and / or at least one intermediate layer (24) at least partially covering the first substrate surface (20a); and at least one capacitor device (30), wherein the at least one capacitor device (30) is constructed in the first substrate (20) and / or a second substrate (32), the second substrate being electrically connected to the first substrate (20) via at least one bonding connection (34). The invention also relates to a method for manufacturing a sensor device. Furthermore, the invention relates to a method for operating a sensor device.

Description

Technical Field

[0001] This invention relates to a sensor device. It also relates to a method for manufacturing the sensor device. Furthermore, this invention relates to a method for operating the sensor device. Background Technology

[0002] Figure 1 A schematic partial illustration of a conventional magnetic sensor is shown.

[0003] exist Figure 1 The magnetic sensor reproduced as part of the prior art can be referred to as the magnetometer BMM350 (see https: / / www.bosch-sensortec.com / products / motion-sensors / magnetometers / bmm350). This conventional magnetic sensor has a circuit board 10 on which, in addition to the BMM350 sensor 12, three capacitors 14 are mounted. Summary of the Invention

[0004] The present invention provides a sensor device having the features of claim 1, a method for manufacturing the sensor device having the features of claim 7, and a method for operating the sensor device having the features of claim 9.

[0005] Advantages of the invention This invention provides sensor devices, each having at least one capacitor, which can be constructed smaller without significantly increasing overhead compared to standard sensors having at least one capacitor. Therefore, this invention advantageously contributes to the miniaturization of sensor devices, each having at least one capacitor. Consequently, this invention also expands the applicability of sensor devices for various applications. Furthermore, the miniaturization of the sensor devices achieved according to this invention can help save materials on the corresponding sensor devices, thereby enabling the sensor devices according to this invention to be manufactured at a lower cost.

[0006] In an advantageous embodiment, the sensor device is designed and / or programmed such that at least one component of the sensor device can be energized using the charge temporarily stored on the at least one capacitor device. Thus, the at least one capacitor device, constructed in a space-saving manner in the first and / or second substrate, can advantageously serve as an energy storage / current storage device. In particular, the sensor device can be designed and / or programmed such that at least one measuring bridge having at least one sensing element and / or an application-specific integrated circuit (ASIC) of the sensor device can be energized as at least one component of the sensor device using the charge temporarily stored on the at least one capacitor device, thereby stabilizing the corresponding supply voltage of the at least one measuring bridge and / or the ASIC.

[0007] In another advantageous embodiment of the sensor device, the at least one capacitor device is constructed in a second substrate, wherein at least one bonding connection (through which the second substrate is electrically connected to the first substrate) is electrically connected to at least one through-hole electrical contact extending through the first substrate and / or the second substrate. Thus, the two substrates of the embodiment of the sensor device described herein can be integrated into a single chip-scale package in a space-saving manner.

[0008] Preferably, at least one intermediate layer that at least partially covers the surface of the first substrate includes at least one circuit layer having an application-specific integrated circuit (ASIC). Therefore, embodiments of the sensor device described herein can be referred to as sensor devices integrated into an ASIC. Consequently, it is readily possible to integrate embodiments of the sensor device described herein into a molded package.

[0009] As an advantageous extension, the sensor device may also include a redistribution layer that at least partially covers the surface of a second substrate, covering the sensor element layer or the second substrate. Equipping the sensor device with a redistribution layer also facilitates its implementation as a single chip-level package.

[0010] The aforementioned advantages are also achieved by performing the corresponding manufacturing method for the sensor device. In particular, when performing this manufacturing method, the at least one capacitor device can be constructed in the first and / or second substrate using deep trench technology. In this way, the at least one capacitor device can be constructed as an advantageous silicon capacitor in the first and / or second substrate.

[0011] Furthermore, the corresponding method for operating the sensor device also provides the aforementioned advantages. It is explicitly stated that the method for operating the sensor device can be extended based on the embodiments of the sensor device and / or manufacturing method described above.

[0012] Preferably, at least one circuit component, as at least one component of the sensor device, is energized by a charge temporarily stored on the at least one capacitor device, thereby generating a magnetic field. This magnetic field generates a corresponding polarization in the corresponding free layer of at least one sensitive element constructed as a magnetoresistive element. "Generating" polarization can also be understood as "restoring" polarization. Therefore, the implementation of the method described herein is well-suited for so-called magnetic reset, by which the at least one magnetoresistive element used in the magnetoresistive measurement method can recover from a strong external magnetic field, especially from so-called magnetic shock, and the performance of the sensor device used as a magnetic sensor device can be optimized.

[0013] Alternatively or supplementarily, at least one measuring bridge having at least one sensing element and / or a dedicated integrated circuit of the sensor device may be energized as at least one component of the sensor device using charge temporarily stored on the at least one capacitor device, thereby stabilizing the corresponding supply voltage of the at least one measuring bridge and / or the dedicated integrated circuit. This method can also improve the operation of the sensor device described herein. Attached Figure Description

[0014] Other features and advantages of the invention are illustrated below with reference to the accompanying drawings. These drawings show: Figure 1 A schematic diagram of a conventional magnetic sensor. Figure 2 : A schematic diagram of the first embodiment of the sensor device; Figure 3a and 3b : A schematic diagram of the second embodiment of the sensor device; Figure 4 : A schematic diagram of the third embodiment of the sensor device; Figure 5 : A flowchart illustrating one embodiment of a method for manufacturing a sensor device; and Figure 6 : A flowchart illustrating one implementation of a method for operating a sensor device. Detailed Implementation

[0015] Figure 2 A schematic diagram of a first embodiment of the sensor device is shown.

[0016] exist Figure 2The schematically reproduced sensor device has a substrate 20 with a substrate surface 20a, which may in particular be a semiconductor substrate 20, especially a silicon substrate 20. A sensor element layer 22 is arranged on and / or above the substrate surface 20a, such that the sensor element layer 22 covers the substrate surface 20a and / or at least partially covers at least one intermediate layer 24 of the substrate surface 20a. The sensor element layer 22 is constructed using at least one sensitive element (not shown) arranged in the sensor element layer 22, such that at least one physical quantity and / or at least one chemical concentration can be measured using the at least one sensitive element of the sensor element layer 22.

[0017] Therefore, the sensor device can be used, for example, as an acceleration, yaw rate, gas, humidity, and / or pressure sensor device. Preferably, the sensor device can be used (at least) as a magnetic sensor device. If necessary, the at least one sensing element can be at least one magnetoresistive element, such as at least one TMR element (Tunnel Magnetoresistance), at least one GMR element, and / or at least one AMR element (Anisotropic Magnetoresistance). For example, the at least one magnetoresistive element can be electrically integrated into at least one (not shown) measuring bridge to enable a magnetoresistive measurement method for determining the corresponding magnetic field strength along at least one predetermined spatial direction.

[0018] At least one intermediate layer 24 that at least partially covers the substrate surface 20a is, exemplary, (at least) a circuit layer 24 having an application-specific integrated circuit (ASIC). Although in Figure 2 While not explicitly shown in the image, the sensor device may also have at least one additional layer as at least one intermediate layer 24. Preferably, the sensor device also has a redistribution layer 26 (RDL). For example, the redistribution layer 26 may at least partially cover the sensor element layer 22. If desired, at least one solder ball 28 may also be fastened to the redistribution layer 26 on the side of the redistribution layer 26 facing away from the substrate 20.

[0019] exist Figure 2The sensor device schematically reproduced also has at least one (schematically shown) capacitor device 30, which is constructed in the substrate 20. This can also be described as the integration of the at least one capacitor device 30 in the substrate 20. The integration of the at least one capacitor device 30 in the substrate 20 enables the sensor device to be constructed as a chip-scale package, with a volume significantly smaller than that of conventional sensor types having a circuit board, a sensor mounted on the circuit board, and at least one capacitor additionally mounted on the circuit board. The integration of the at least one capacitor device 30 in the substrate 20 thereby facilitates the miniaturization of the sensor device described herein. The miniaturization of the sensor device achieved can be used to save material thereon, thereby reducing the manufacturing cost of the sensor device described herein.

[0020] The at least one capacitor device 30 can be constructed in the substrate 20, particularly using deep trench technology. In this case, the at least one capacitor device 30 can also be referred to as a silicon capacitor. Typical capacitance values ​​of silicon capacitors in the substrate 20 are generally in the range of 500 nF (nanofarad) to 1 to 2 µF (microfarad). In particular, the capacitance value can be in the range of 100 nF (nanofarad) to 600 nF (nanofarad).

[0021] The integration of at least one capacitor device 30 in the substrate 20 also facilitates the integration of the sensor device into a package, especially a molded package. Therefore, the sensor device described herein can also be referred to as a highly integrated wafer-level chip-scale package (highly integrated WLCSP).

[0022] The sensor device is preferably designed and / or programmed such that at least one component of the sensor device can be energized / energized using the charge temporarily stored on the at least one capacitor device 30. Therefore, the at least one capacitor device 30 can be used as an energy storage / current storage device for a variety of advantageous applications. Advantageous examples of such applications will be described below.

[0023] Figure 3a and 3b A schematic diagram of a second embodiment of the sensor device is shown.

[0024] exist Figure 3a and 3b The sensor device schematically reproduced in the above-mentioned Figure 2 The difference in the implementation is that the at least one capacitor device 30 is constructed in another substrate 32, which is electrically connected to the substrate 20 via at least one bonding connection 34. Although this is in... Figure 3a While not visually represented, at least one (additional) capacitor device may be additionally integrated into the substrate 20.

[0025] The at least one bonding connection 34 can be constructed between substrates 20 and 32, particularly by means of eutectic bonding or thermocompression bonding. Preferably, the at least one bonding connection 34 is a gold-gold thermocompression bond, because this type of bonding connection can be formed at relatively low temperatures, particularly at temperatures significantly below the Curie temperature. In this way, for example in the case of at least one magnetoresistive element constructed as a sensing element in sensor element layer 22, it is ensured that the at least one magnetoresistive element remains stably magnetized despite the formation of the at least one bonding connection 34.

[0026] In addition, such as Figure 3a Figuratively, the at least one bonding connection 34 (through which the substrate 32 is electrically connected to the substrate 20) can be electrically connected to at least one through-silicon-via (TSV) 36 extending through the substrate 20. In this way, the substrate 32 can be readily applied to the back side 20b of the substrate 20 opposite to the substrate surface 20a by means of the at least one bonding connection 34. If necessary, the at least one bonding connection 34 is "clamped" between the back side 20b and the substrate surface 32a of the substrate 32.

[0027] like Figure 3b As schematically shown, the external supply voltage V and external ground 38 can be electrically connected to the at least one capacitor device 30 in the substrate 32 via the at least one solder ball 28, respectively. In this way, the at least one capacitor device 30 in the substrate 32 can be charged quickly, with low resistance, and reliably.

[0028] about Figure 3a and 3b For other features and characteristics of the sensor device and its advantages, see [link to relevant documentation]. Figure 2 The aforementioned description.

[0029] Figure 4 A schematic diagram of a third embodiment of the sensor device is shown.

[0030] With the above explanation Figure 3a and 3b The implementation methods are different, in Figure 4 In the sensor device, a redistribution layer 26 is formed on the substrate surface 32a of the substrate 32. By electrically connecting at least one bonding connection 34 to at least one through electrical contact 36 extending through the substrate 32, it is convenient to mount the substrate 32 "above" the substrate surface 20a of the substrate 20, which is at least partially covered by layers 22 and 24. In this case, the at least one bonding connection 34 contacts the back side 32b of the substrate 32 opposite to the substrate surface 32a, whereby the at least one bonding connection 34 and layers 22 and 24 are "clamped" between the substrate surface 20a and the back side 32b.

[0031] about Figure 4 For other features and characteristics of the sensor device and its advantages, see [link to relevant documentation]. Figure 2 And the aforementioned description of 3.

[0032] All of the aforementioned sensor devices solve the conventional problem of equipping the corresponding sensor devices with the possibility of energy / current storage or temporary storage, without requiring the use of at least one external capacitor as in the prior art described above. Therefore, the footprint of the aforementioned sensor devices can be less than 1.2 x 1.2 mm. 2 (square millimeters). In particular, the footprint can be as small as 0.7 x 0.7 mm. 2 (square millimeters) and 0.9 x 0.9 mm 2 Therefore, compared with the prior art, the space requirement of the above-mentioned sensor device is significantly reduced. The height of the corresponding sensor device excluding the at least one brazed ball 28 is typically less than 0.5 mm. In addition, the manufacturing cost of the above-mentioned sensor device is reduced because the at least one capacitor device 30 integrated into the corresponding substrate 20 or 32 can be manufactured cheaper than external capacitors of the corresponding quality level.

[0033] All of the aforementioned sensor devices can be manufactured as wafer-level chip-scale packages (WLCSPs). In all of the aforementioned sensor devices, the at least one capacitor device 30 integrated in the corresponding substrate 20 or 32 can be constructed as a so-called silicon capacitor using deep trench technology. Compared to conventional capacitors, this at least one silicon capacitor exhibits better reliability over its lifespan. Furthermore, this silicon capacitor has a consistently stable capacitance that is (almost) independent of the current temperature. It should also be noted that the aforementioned sensor devices have relatively high temperature resistance, enabling them to operate reliably even at higher temperatures of at least 125°C. In addition, this silicon capacitor also has a nearly constant capacitance under both AC and DC voltages. For these reasons, silicon capacitors can be designed with a smaller nominal capacitance compared to conventional capacitors.

[0034] Each of the aforementioned sensor devices can be configured, in particular, as a magnetic sensor device, enabling the determination of a corresponding magnetic field strength along at least one predetermined spatial direction. Specifically, the corresponding sensor device can be a 3D magnetic sensor device. Sensor devices configured as magnetic sensors can be used, for example, in smartphones, smartwatches, or TWS (True Wireless Stereo) earphones.

[0035] Figure 5 A flowchart illustrating one implementation of a method for manufacturing a sensor device is shown.

[0036] In method step S1 of the manufacturing method described below, the first substrate surface of the first substrate and / or at least one intermediate layer that at least partially covers the first substrate surface is covered by a sensor element layer. Furthermore, in method step S1, the sensor element layer is configured to have at least one sensitive element disposed therein. For other components that may be attached to and / or constructed on the first substrate, see the description of the aforementioned embodiments of the sensor device. Examples of the at least one sensitive element in the sensor element layer have been given above.

[0037] In another method step S2, at least one capacitor device is formed in a first substrate and / or a second substrate. This at least one capacitor device is preferably formed in the first substrate and / or the second substrate using a deep trench technique. By way of example only, in the embodiment described herein, the at least one capacitor device is formed in the second substrate, so the manufacturing method may also include at least one of method steps S3 and S4 (optionally). The first substrate may be thinned selectively in method step S3, and the second substrate may be thinned selectively as method step S4. Here, the first / second substrate is preferably thinned to a maximum thickness of 50 µm to 90 µm.

[0038] If necessary, as method step S5, at least one through-hole electrical contact can be formed through the first substrate or through the second substrate. If the sensor device produced by the manufacturing method described herein also utilizes a second substrate in addition to the first substrate, then as method step S6, after performing at least method steps S1 and S2 and possibly at least one of method steps S3 to S5, the first substrate is electrically connected to the second substrate by at least one bonding connection. An example of this at least one bonding connection has been mentioned above. Optionally, in method step S7, a redistribution layer and / or at least one solder ball may also be assembled on the first substrate and / or the second substrate.

[0039] The aforementioned method steps S1 to S7 can all be performed at the wafer level using a first wafer as a first substrate and a second wafer as a second substrate. This allows for the simultaneous fabrication of multiple sensor devices, which further reduces manufacturing costs. If necessary, in the final method step S8, the monolithic wafer formed from the first and second wafers using method step S6 is individually separated into multiple sensor devices.

[0040] A particular advantage of the manufacturing method described herein is that the calibration and / or testing of the sensor device can be performed before the individual separation of the entire wafer. Therefore, method step S9 can also be performed before method step S8, in which the at least one subsequent sensor device is calibrated, particularly including at least one capacitor device, especially as a final test or final calibration. This is not possible when equipping such a sensor device with an external capacitor.

[0041] Figure 6 A flowchart illustrating one implementation of a method for operating a sensor device is shown.

[0042] It is explicitly stated that the feasibility of the method described below is not limited to the aforementioned sensor devices. Alternatively, the method can be performed with (almost) any sensor device, provided that the corresponding sensor device is equipped with at least one sensitive element arranged in a sensor element layer that covers the first substrate surface of the first substrate of the sensor device and / or at least partially covers at least one intermediate layer of the first substrate surface.

[0043] When performing the method described herein, at least one component of the sensor device is energized using a charge temporarily stored on at least one capacitor device of the sensor device, wherein the at least one capacitor device is constructed in a first substrate and / or a second substrate, the second substrate being electrically connected to the first substrate via at least one bonding connection. For example, in method step S10, at least one measuring bridge having at least the at least one sensing element and / or an application-specific integrated circuit (ASIC) of the sensor device may be energized as at least one component of the sensor device using the charge temporarily stored on the at least one capacitor device, such that the corresponding supply voltage of the at least one measuring bridge and / or the ASIC is stabilized.

[0044] Alternatively or supplementarily, in method step S11, at least one circuit component, as the at least one component of the sensor device, may be energized using a charge temporarily stored on the at least one capacitor device, thereby generating a magnetic field. Advantageously, the generated magnetic field can, for example, generate a corresponding polarization of the corresponding free layer of at least one sensing element constructed as a magnetoresistive element. This can also be described as a so-called magnetic reset, by which the corresponding magnetoresistive element can recover from a strong external magnetic field, especially a so-called magnetic shock, or by which the performance of the sensor device can be optimized. An example of this is the so-called chopper, i.e., a magnetic reset with an alternating current direction, thereby compensating for measurement errors caused by temperature or stress variations.

Claims

1. A sensor device, comprising: At least one first substrate (20) having a first substrate surface (20a); A sensor element layer (22) having at least one sensitive element disposed therein, wherein, The sensor element layer (22) covers the first substrate surface (20a) and / or at least partially covers at least one intermediate layer (24) of the first substrate surface (20a). and At least one capacitor device (30); Its features are, The at least one capacitor device (30) is constructed in the first substrate (20) and / or the second substrate (32), the second substrate being electrically connected to the first substrate (20) via at least one bonding connection (34).

2. The sensor device according to claim 1, wherein, The sensor device is designed and / or programmed such that at least one component of the sensor device can be energized using the charge temporarily stored on the at least one capacitor device (30).

3. The sensor device according to claim 2, wherein, The sensor device is designed and / or programmed such that at least one measuring bridge having at least one sensing element and / or a dedicated integrated circuit of the sensor device can be energized as at least one component of the sensor device using charge temporarily stored on the at least one capacitor device (30), thereby stabilizing the corresponding supply voltage of the at least one measuring bridge and / or the dedicated integrated circuit.

4. The sensor device according to any one of the preceding claims, wherein, The at least one capacitor device (30) is constructed in the second substrate (32), wherein the at least one bonding connection (34) is electrically connected to at least one through electrical contact (36) extending through the first substrate (20) or the second substrate (32), and the second substrate (32) is electrically connected to the first substrate (20) via the at least one bonding connection.

5. The sensor device according to any one of the preceding claims, wherein, The at least one intermediate layer (24) that at least partially covers the surface (20a) of the first substrate includes at least one circuit layer (24) having an application-specific integrated circuit.

6. The sensor device according to any one of the preceding claims, wherein, The sensor device includes a redistribution layer (26) that at least partially covers the second substrate surface (32a) of the sensor element layer (22) or the second substrate (32).

7. A method for manufacturing a sensor device, comprising the following steps: A sensor element layer (22) covers a first substrate surface (20a) of a first substrate (20) and / or at least partially covers at least one intermediate layer (24) (S1) of the first substrate surface (20a), the sensor element layer having at least one sensitive element disposed in the sensor element layer (22); and Construct at least one capacitor device (30); Its features are, The at least one capacitor device (30) is constructed in the first substrate (20) and / or in the second substrate (32) (S2), the second substrate being electrically connected to or to the first substrate (20) via at least one bonding connection (34) (S6).

8. The manufacturing method according to claim 7, wherein, The at least one capacitor device (30) is constructed in the first substrate (20) and / or the second substrate (32) using deep trench technology.

9. A method for operating a sensor device having at least one sensitive element disposed in a sensor element layer (22), the sensor element layer covering a first substrate surface (20a) of a first substrate (20) of the sensor device and / or at least partially covering at least one intermediate layer (24) of the first substrate surface (20a), the method comprising the steps of: At least one component of the sensor device is energized using the charge temporarily stored on at least one capacitor device (30) of the sensor device; Its features are, The at least one capacitor device (30) is constructed in the first substrate (20) and / or in the second substrate (32), the second substrate being electrically connected to the first substrate (20) via at least one bonding connection (34).

10. The method according to claim 9, wherein, At least one circuit component, as the at least one component of the sensor device, is energized by a charge temporarily stored on the at least one capacitor device (30), thereby generating a magnetic field, which in turn generates a corresponding polarization (S11) of the corresponding free layer of at least one sensitive element constructed as a magnetoresistive element.

11. The method according to claim 9 or 10, wherein, At least one measuring bridge having the at least one sensitive element and / or a dedicated integrated circuit of the sensor device, as the at least one component of the sensor device, is energized by a charge temporarily stored on the at least one capacitor device (30) to stabilize the corresponding supply voltage of the at least one measuring bridge and / or the dedicated integrated circuit (S10).

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