Sensor device

Abstract

The embodiment of the invention relates to a sensor device. A sensor device (100) includes a semiconductor chip (110) and a package (150) that encapsulates the semiconductor chip (110). The semiconductor chip (110) includes an integrated sensor circuit (115) configured to sense a characteristic of a gas in the vicinity of the semiconductor chip (110). The package (150) comprises electrical contacts to the integrated sensor circuit (115) such that gas can enter the package (150) and reach at least one gas port (152) of the semiconductor chip (110), a heating element (155) configured to heat an interior portion of the package (150).

Description

Technical Field

[0001] The present invention relates generally to sensor devices, and more particularly to sensor devices for sensing properties of gases. Background Art

[0002] In order to sense the properties of a gas, various semiconductor-based devices may be utilized. Such sensor devices typically include a semiconductor chip that is adapted to sense specific properties of a gas in the environment of the semiconductor chip. For example, the semiconductor chip may be adapted to sense the presence and / or concentration of a certain type of gas.

[0003] In order to stabilize the operation of such sensor devices and / or to avoid adverse effects of humidity in the environment of the semiconductor chip, it is also known to provide the sensor device with an integrated heater. For example, US 2008 / 0134753 A1 describes a sensor device in which the gas sensor chip structure also comprises a heater.

[0004] Semiconductor chips used for sensing gas characteristics are typically customized according to their specific purpose (eg, the type of gas to be sensed), and adding an integrated heater to the chip structure may increase the complexity of the design and manufacture of the semiconductor chip.

[0005] Therefore, there is a need for techniques that allow efficient provision of gas sensor devices with heating capabilities. It is an object of the present disclosure to meet this need. Summary of the invention

[0006] The present disclosure provides a sensor device. The sensor device includes a semiconductor chip and a package body that encapsulates the semiconductor chip. The semiconductor chip includes an integrated sensor circuit that is configured to sense the characteristics of a gas near the semiconductor chip. The package body that encapsulates the semiconductor chip includes an electrical contact to the integrated sensor circuit and at least one gas port, the electrical contact being used, for example, to interconnect the integrated sensor circuit with a circuit board (such as a PCB), the gas port enabling gas to enter the package body and reach the semiconductor chip. In addition, the package body includes a heating element that is configured to heat an internal portion of the package body. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Examples of the present disclosure will be described with reference to the following drawings, wherein like reference numerals refer to like elements.

[0008] Figure 1 An electronic system with a sensor device according to an embodiment of the present disclosure is schematically shown.

[0009] Figure 2 An example of a sensor device according to an embodiment of the present disclosure is schematically shown.

[0010] Figure 3Another example of a sensor device according to an embodiment of the present disclosure is schematically shown.

[0011] Figure 4 Another example of a sensor device according to an embodiment of the present disclosure is schematically shown.

[0012] Figure 5A and Figure 5B Another example of a sensor device according to an embodiment of the present disclosure is schematically shown.

[0013] Figure 6 Another example of a sensor device according to an embodiment of the present disclosure is schematically shown.

[0014] Figure 7 Another example of a sensor device according to an embodiment of the present disclosure is schematically shown.

[0015] Figure 8 Another example of a sensor device according to an embodiment of the present disclosure is schematically shown.

[0016] Fig. 9 Another example of a sensor device according to an embodiment of the present disclosure is schematically shown.

[0017] Fig.10 Another example of a sensor device according to an embodiment of the present disclosure is schematically shown.

[0018] Fig.11 A flowchart for explaining a method of manufacturing a sensor device according to an embodiment of the present disclosure is shown.

[0019] It should be understood that the above-identified drawings are not intended to limit the scope of the present disclosure. Instead, these drawings are provided to aid in understanding the present disclosure. It will be readily understood by those skilled in the art that aspects of the present invention shown in one drawing may be combined with aspects in another drawing, or may be omitted without departing from the scope of the present disclosure. DETAILED DESCRIPTION

[0020] The concepts as described in the present disclosure relate to a sensor device for sensing one or more characteristics of one or more gases. Such a sensor device is also referred to herein as a "gas sensor device". The characteristic to be sensed may, for example, correspond to the presence and / or concentration of a certain gas type in the environment of the gas sensor device. For example, a gas sensor device may be used to detect the presence and / or concentration of hydrogen. However, other types of gases may also be detected, such as carbon dioxide, carbon monoxide, oxygen, methane, gas mixtures, etc. In addition, the gas sensor device may be used to detect the pressure of a gas or a change in the pressure of a gas. A specific example of a gas sensor device that operates by detecting a change in gas pressure is a microphone.

[0021] In the illustrated concept, the gas sensor device includes a semiconductor chip and a package that encapsulates the semiconductor chip. The semiconductor chip includes an integrated sensor circuit that is configured to sense the characteristics of the gas near the semiconductor chip. The specific configuration of the integrated circuit and the semiconductor chip depends on the characteristics and type of the gas to be sensed. In some cases, the semiconductor chip may include a MEMS (micro-electromechanical system) structure suitable for sensing the characteristics.

[0022] The package encapsulating the semiconductor chip provides electrical contacts to the integrated sensor circuit, which are used, for example, to interconnect the integrated sensor circuit with a circuit board (such as a PCB). In addition, the package provides at least one gas port, which enables the gas to be sensed to enter the package and reach the semiconductor chip. With such a package, the gas sensor device can be installed in various types of electronic systems, for example, in a control system for an internal combustion engine or in a processing machine.

[0023] However, in actual use, the gas sensor device may exhibit cross-sensitivity with respect to other gases, but not the gas to be sensed. For example, a gas sensor device used to sense the presence or concentration of hydrogen may also react to the presence of humidity (i.e., water). In addition, the response of the gas sensor device may also be temperature-dependent. As a result, the accuracy of the measurement results provided by the gas sensor device may be adversely affected.

[0024] In the illustrated concept, the package for encapsulating the semiconductor chip is also provided with at least one heating element, which is configured to heat the inner part of the package. Due to the heating, other media besides the gas to be sensed can be at least partially removed from the interior of the package and therefore from the vicinity of the semiconductor chip. In this way, cross-sensitivity problems can be reduced. In addition, heating can be used to provide a stable environment for sensing, thereby improving accuracy.

[0025] By integrating the heating element in the package, design optimization of the gas sensor device for various applications can be facilitated. Specifically, the design of the semiconductor chip can be modified and customized in various ways without modifying the package and the heating element.

[0026] Figure 1 An example electronic system equipped with a gas sensor device 100 according to the illustrated concepts is schematically shown. As shown, the gas sensor device 100 is mounted on a circuit board 200 (eg, a PCB). The circuit board 200 may connect the gas sensor device 100 to various other components of the electronic system.

[0027] As further shown, the gas sensor device 100 is based on a semiconductor chip 110 encapsulated in a package 150. In the example shown, the semiconductor chip 110 is provided with a gas sensing region 111, which is exposed to a gas in the vicinity of the semiconductor chip 110. The semiconductor chip 110 is suitable for sensing one or more characteristics of the gas to which the gas sensing region 111 is exposed. The integrated circuit 115 of the semiconductor chip 110 is configured to provide an electrical response signal representative of the characteristic to be sensed. It should be noted here that the specific configuration of the gas sensing region 111 and / or the integrated circuit 115 generally depends on the characteristic and gas type to be sensed, and can be customized according to the application for which the gas sensor 100 is to be used. In some cases, the gas sensing region 111 and the integrated circuit can be MEMS-based.

[0028] The package 150 encapsulates the semiconductor chip by a housing material, such as plastic and / or ceramic, and provides an electrical interface between the semiconductor chip 110 of the semiconductor chip 110 and the circuit board 200. More specifically, the package 150 can provide an electrical interface between the integrated circuit 115 of the semiconductor chip 110 and the circuit board 200. To this end, the package 150 is provided with a carrier 151 (e.g., in the form of a lead frame) on which the semiconductor chip 110 is mounted. The carrier 151 can not only provide electrical contact from the outside to the inside of the package 150, but also provide internal electrical interconnection, such as providing electrical interconnection between different parts of the integrated circuit 115 or between the semiconductor chip 110 and other components included in the package (e.g., another semiconductor chip or one or more discrete circuit components). In addition, the package is provided with at least one gas port 152, which allows gas from the outside of the package 150 to enter the internal part of the package 150, so that the gas sensing area 111 of the semiconductor chip 110 can be exposed to the gas to be sensed.

[0029] As further shown, a heating element 155 is integrated in the package 150. The heating element 155 allows heating of the inner part of the package 150. In this way, other media (e.g. moisture) in addition to the gas to be sensed can be discharged from the package 150. In addition, the temperature inside the package 150 can be stabilized. The heating element 155 can be electrically driven. In this case, the electrical power for the heating element 155 can be supplied from the circuit board 200 via the carrier 151. However, it should be noted that in some scenarios, the heating element 155 can also operate as a reverse heat sink, using the contact structure 151 to conduct heat to the inner part of the package 150. Further details on possible implementations of the heating element 155 will be explained below.

[0030] Figure 2An example of a gas sensor device 100 is schematically shown, wherein the heating element 155 is partially implemented by a carrier 151. As mentioned above, the carrier 151 may correspond to a lead frame of a package and may provide electrical contact with respect to the semiconductor chip 110. By way of example, Figure 2 1A is shown extending from the outside into the package body 150. Bonding wires 156 provide electrical connection of the electrical leads 151A to the semiconductor chip 110. It should be noted that for better overview, Figure 2 Only one electrical lead 151A is shown for connection to the semiconductor chip 110 , but in actual implementations, there are typically a plurality of such electrical leads 151A for connection to the semiconductor chip 110 .

[0031] As further shown, the carrier 151 also provides additional electrical leads 151B which have the purpose of providing electrical energy to the heating element 155. Figure 2 In the example of , the heating element 155 is implemented based on one or more bonding wires 156' connected to the electrical lead 151B. By providing electrical energy to the electrical lead 151B, current is injected into the bonding wire 156' and the lead 151B, thereby causing ohmic heating.

[0032] With this structure, the heating element 155 can be realized in a simple manner. The characteristics of the heating element 155 can be adjusted by selecting the number of bonding wires 156', the type of bonding wires and / or the length of the bonding wires 156'.

[0033] Figure 3 Another example of a gas sensor device 100 is schematically shown. Figure 3 In the example of FIG. 1 , the heating element 155 is implemented by a discrete resistor 157, such as an SMD (surface mount device) resistor. In addition, the structure and function of the gas sensor device 100 can be similar to that of the combination Figure 1 and Figure 2 Those structures and functions described.

[0034] Figure 4 Another example of a gas sensor device 100 is schematically shown. For a better overview, Figure 4 FIG. 1 shows a partial top view of the gas sensor device 100 , including a bottom portion 150B of the package body 150 and a carrier 151 based on a patterned lead frame. Figure 4 In the example of , the heating element 155 is realized by the patterned structure 158 of the lead frame. It can be seen that the patterned structure 158 is connected to the electrical lead 151B. By supplying electrical energy to the contact 151B, current is injected into the patterned structure 158 and the lead 151B, thereby causing ohmic heating. Figure 4In the example of , the patterned structure 158 is provided with a meandering shape, which can help tune its ohmic resistance to a desired range without requiring too much space. However, it should be noted that various other shapes are also possible.

[0035] Figure 5A and Figure 5B Another example of a gas sensor device 100 is schematically shown, which is generally similar to Figure 4 However, with Figure 4 Compared to the example in Figure 5A and Figure 5B In the example of FIG. 1 , the bottom portion 150B of the package 150 includes one or more vent ports 153. The one or more vent ports 153 can be implemented by a void area of ​​the patterned structure 158 of the lead frame, which is not covered by other packaging materials (e.g., plastic or ceramic housing materials). The vent port 153 can be arranged on the opposite side of the package 150 relative to the gas port 152. With this structure, it is possible to enhance the ventilation of the inner portion of the package 150 due to the stacking effect.

[0036] Figure 6 Another example of a gas sensor device 100 is schematically shown. Figure 6 In the example of , the heating element 155 is realized by a Peltier element 159. Such a Peltier element 158 ​​can be provided by a layer system embedded in the package 150, for example by adding additional layers to the lead frame forming the carrier 151. Alternatively, the Peltier element can also be provided in the form of a discrete component, similar to Figure 3 The SMD resistors in the example. Figure 6 In the example of , the Peltier element 159 is formed by an additional layer on the lead frame and is connected to the electrical lead 151B by the bonding wire 156. By supplying electrical energy to the electrical lead 151B, the Peltier element 159 can provide heating due to the Peltier effect. However, it should be noted that in some scenarios, the Peltier element 159 can also be used to cool the internal part of the package 150. Therefore, the Peltier element 159 can be used to stabilize the conditions in the internal part of the package 150.

[0037] Figure 7 Another example of a gas sensor device 100 is schematically shown. Figure 7 In the example of , the heating element 155 is implemented by a thermal conductor 160 that operates as a reverse heat sink. The thermal conductor 160 may be formed of a metallic material. Figure 7In the example of FIG. 1 , it is assumed that the thermal conductor 160 is implemented as part of the carrier 151, for example as part of a lead frame. For example, the lead frame can be formed of a dual-gauge material, using the higher-gauge material to form the thermal conductor 160. In addition, the metal material forming the thermal conductor 160 can be welded to the lead frame. In addition, the thermal conductor 160 can be formed as part of a three-dimensional lead frame structure, so that the thermal conductor 160 can be formed on another level than the structure used to provide the electrical leads 151A.

[0038] like Figure 7 As shown, the thermal conductor 160 is provided with a thermal lead 161 extending from the outside of the package 150 to the inside of the package 150. Outside the package 150, the thermal lead 161 can be connected to an external heat reservoir (e.g., on a circuit board). The external heat reservoir can absorb heat from the environment or some external cooling system. In some cases, such an external heat reservoir can also be actively heated by an external heater.

[0039] It should be noted that Figures 1 to 7 The arrangement of the heating element 155 shown is merely exemplary and other arrangements are possible. In some scenarios, the heating element 155 may be arranged side by side with the semiconductor chip 110, for example, as shown in FIG. Figure 1-Figure 6 In other scenarios, the heating element 155 may be arranged below the semiconductor chip 110 , for example, as an additional layer on a carrier of the semiconductor chip 110 . Figure 7 The arrangement of is an example of such a scenario. Another example of such a scenario is Figure 8 As shown in Figure 8 As further shown in the example of FIG. 1 , the heating element may also be arranged as a cover of the semiconductor chip 110 or as part of a cover of the semiconductor chip 110, arranged on other inner surfaces of the package 150, or arranged at any internal stacking position within the package 150. Such an arrangement of the heating element 155 may also be achieved by implementing a heater element 155 based on a polyimide heating foil.

[0040] In some scenarios, the gas sensor device 100 may also be provided with one or more isolation elements that provide thermal isolation of the inner portion of the package 150 . Fig. 9 A corresponding example is schematically shown, in which an isolation element 170 is arranged on the inner side surface of the package body 150. Such an isolation element can be formed of a material with low thermal conductivity (such as a plastic material). By using such an isolation element, the efficiency of the heating element 155 can be improved.

[0041] In some scenarios, the heating element 155 may be operated in a controlled manner, for example, by adjusting the electrical power supplied to the heating element 155. In this case, a control circuit for controlling the heating element 155 may also be integrated in the package 150. Fig.10 A corresponding example is schematically shown. Fig.10 In the example of , in addition to the semiconductor chip 110 suitable for performing sensing, the package 150 also includes another semiconductor chip 180 suitable for controlling the heating element 155. In this scenario, the electric power feeding to the heating element 155 can be completed by the control circuit 185 integrated in the other semiconductor chip 180. Such a control circuit 185 may also include a temperature sensor for measuring the temperature in the internal part of the package 150. Alternatively, such a temperature sensor may also be a discrete component in the package, such as a discrete resistor or a discrete diode.

[0042] It should be noted that the combination Figures 1 to 10 The features of the gas sensor device 100 described above can be combined in various ways. For example, different types of heating elements 155 shown in the figure can be combined in the same gas sensor device 100. For example, the heating element 155 can include a combination of two or more of the following: Figure 2 The bonding wire 156' shown, Figure 3 The discrete resistor 157 shown, such as Figure 4 , Figure 5A and Figure 5B The patterned structure 158 of the lead frame shown, as Figure 6 The Peltier element 159 shown, or Figure 7 The heat conductor 160 is shown. In addition, Figure 5A and Figure 5B One or more vent ports 153 shown in the example may also be provided Figures 1 to 3 or Figures 6 to 10 in any example.

[0043] Fig.11 A flow chart is shown for schematically illustrating the fabrication of a gas sensor device according to the described concepts. Fig.11 The method may, for example, be used to manufacture any of the gas sensor devices 100 described above. Fig.11 The method can be performed by the device manufacturer. The method can be performed in an automatic or semi-automatic manner.

[0044] exist Fig.11 In the method of , block 1110 involves obtaining a semiconductor chip having an integrated circuit for sensing at least one characteristic of a gas. For example, block 1110 may involve obtaining semiconductor chip 110. The semiconductor chip may be obtained from a chip supplier or may be manufactured as an initial part of block 1110.

[0045] At block 1120, the semiconductor chip obtained at block 1110 is packaged. This involves packaging the semiconductor chip in a package. The package provides electrical contact to the integrated sensor circuit. In addition, the package provides at least one gas port so that gas can enter the package and reach the semiconductor chip. As another element, the package includes a heating element configured to heat an internal portion of the package. The package may, for example, have a Figures 1 to 10 The structure described.

[0046] It can be seen that through Fig.11 By means of the method, a semiconductor chip for gas sensing can be supplemented with a heating capability without modifying the semiconductor chip design.

[0047] In view of the above, examples provided by the present disclosure include a sensor device comprising a semiconductor chip and a package that encapsulates the semiconductor chip, wherein the semiconductor chip includes an integrated sensor circuit configured to sense characteristics of a gas near the semiconductor chip, and wherein the package includes: electrical contacts to the integrated sensor circuit (e.g., electrical contacts for contacting the integrated sensor circuit to a circuit board), at least one gas port that enables gas to enter the package and reach the semiconductor chip, and a heating element configured to heat an internal portion of the package.

[0048] The package may include a carrier on which the semiconductor chip is mounted and which supports electrical contacts, such as the carrier 151 mentioned above. At least a portion of the heating element may be integrated in the carrier. This portion may, for example, include leads to the heating element and / or the heating element itself, such as an e-lead structure.

[0049] The carrier may include a first set of leads for providing electrical contact to the sensor circuit, such as the leads 151A mentioned above, and a second set of leads for providing electrical energy to the heating element, such as the leads 151B mentioned above. In this case, the heating element may include another lead structure of the carrier, for example, such as the patterned structure 158 of the lead frame mentioned above. The other lead structure may be connected to the second set of leads and configured to provide ohmic heating by a current flowing through the second set of leads. Alternatively or additionally, the heating element may include bonding wires connected to the second set of leads, such as Figure 2 The bonding wire 156' in the example of FIG.

[0050] In some scenarios, the package may include a cover arranged on the semiconductor chip. In this case, at least a portion of the heating element may be integrated in the cover, for example, Figure 8 as shown in the example.

[0051] In some scenarios, the heating element may be at least partially embedded in the material of the package, e.g. Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5A , Figure 5B , Figure 6 , Figure 7 , Fig. 9 and Fig.10 as shown in the example.

[0052] In some scenarios, the heating element may include a heating resistor, such as Figure 2 and Figure 8 In some cases, such a heating resistor can be based on a polyimide film.

[0053] In some scenarios, the heating element may include a Peltier element, such as Figure 6 as shown in the example.

[0054] In some scenarios, the heating element may include a thermal conductor configured to conduct heat from outside the package into the package, for example, Figure 7 as shown in the example.

[0055] In some scenarios, the sensor device may further include at least one vent port that is in gas communication with at least one gas port, for example, Figure 5A and Figure 5B In this case, at least one gas port and at least one vent port may be located on opposite sides of the package.

[0056] In some scenarios, the sensor device may further include at least one isolation element configured to provide thermal isolation of the interior portion of the package relative to the exterior of the package, such as Fig. 9 The isolation element in the example.

[0057] In some scenarios, the sensor device may further include another semiconductor chip encapsulated by the package body, the other semiconductor chip including a control circuit configured to control the operation of the heating element, for example, Fig.10 Another semiconductor chip 180 in the example.

[0058] In some scenarios, the sensor circuit can be configured to detect the presence of hydrogen in the gas. In some scenarios, the sensor circuit can be configured to detect the pressure of the gas or a change in the pressure of the gas. In some scenarios, the sensor device can be a microphone.

[0059] It should be noted that the concepts and examples described above are susceptible to various modifications. For example, the concepts can be applied to various sensor devices configured to sense gas property types, not limited to the examples of properties mentioned above. Thus, the concepts described can be applied to semiconductor chips of various types and designs. Furthermore, the concepts can be applied in conjunction with various types of packages, such as dual in-line packages, pin grid array packages, ball grid array packages, land grid array packages, or surface mount packages.

Claims

1. A sensor device (100), comprising: A semiconductor chip (110) comprising an integrated sensor circuit (115) configured to sense a property of a gas in the vicinity of the semiconductor chip (110); as well as A package (150) packages the semiconductor chip (110) and comprises: an electrical contact (151A) to the integrated sensor circuit (115); at least one gas port (152) to enable the gas to enter the package (150) and reach the semiconductor chip (110); and A heating element (155) is configured to heat an inner portion of the package (150).

2. The sensor device (100) according to claim 1, wherein the package (150) comprises a carrier (151) on which the semiconductor chip is mounted and which supports the electrical contacts (151A); and At least a portion of the heating element (155) is integrated into the carrier.

3. The sensor device (100) according to claim 2, The carrier (151) includes a first set of leads (151A) for providing the electrical contact to the sensor circuit (115) and a second set of leads (151B) for providing electrical energy to the heating element (155).

4. The sensor device (100) according to claim 3, The heating element (155) comprises a further lead structure (158) of the carrier, the further lead structure being connected to the second set of leads (151B) and being configured to provide ohmic heating by a current flowing through the second set of leads (151B).

5. The sensor device (100) according to claim 3 or 4, The heating element (155) includes a bonding wire (156') connected to the second set of leads (151B).

6. The sensor device (100) according to any one of the preceding claims, The package (150) comprises a cover arranged on the semiconductor chip (110), and At least a portion of the heating element (155) is integrated into the cover.

7. The sensor device (100) according to any one of the preceding claims, The heating element (155) is at least partially embedded in the material of the packaging body (150).

8. The sensor device (100) according to any one of the preceding claims, The heating element (155) comprises a heating resistor (157).

9. The sensor device (100) according to claim 8, The heating resistor (157) is based on a polyimide film.

10. The sensor device (100) according to any one of the preceding claims, The heating element (155) comprises a Peltier element (159).

11. The sensor device (100) according to any one of the preceding claims, The heating element (155) comprises a thermal conductor (160) configured to conduct heat from outside the package (150) into the package (150).

12. The sensor device (100) according to any one of the preceding claims, further comprising: At least one vent port (153) is in gas communication with the at least one gas port (152).

13. The sensor device (100) according to claim 12, The at least one gas port (152) and the at least one vent port (153) are located on opposite sides of the package body (150).

14. The sensor device (100) according to any one of the preceding claims, further comprising: At least one isolation element (170) is configured to provide thermal isolation of an interior portion of the package (150) relative to an exterior of the package (150).

15. The sensor device (100) according to any one of the preceding claims, further comprising: another semiconductor chip (180) packaged by the package body (150), The further semiconductor chip (180) comprises a control circuit (185) configured to control the operation of the heating element (155).

16. The sensor device (100) according to any one of the preceding claims, The sensor circuit (115) is configured to detect the presence of hydrogen in the gas.

17. The sensor device according to any one of the preceding claims, The sensor circuit (115) is configured to detect the pressure of the gas or a change in the pressure of the gas.

18. The sensor device (100) according to any one of the preceding claims, The sensor device (100) is a microphone.

Images