Apparatus including MEMS sensor and method of manufacturing same
By using a combination of fluorine-free gel and a low-thickness protective coating on MEMS sensors, the environmental pollution problem caused by PFAS gels is solved, providing effective protection and performance maintenance.
Patent Information
- Application Number
- CN202510490164.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2024-04-29
- Filing Date
- 2025-04-18
- Publication Date
- 2025-10-31
AI Technical Summary
The use of PFAS gel in existing MEMS sensors poses an environmental pollution risk, leading to legislative restrictions and necessitating the search for alternative materials to provide protection.
A combination of fluorine-free gel and protective coating is used, with a coating thickness of less than 100 nm, to protect MEMS sensors and bonding wires from corrosion, while the gel provides mechanical protection.
This achieves effective protection for MEMS sensors, avoiding environmental pollution, while maintaining sensor functionality and performance, and reducing environmental impact.
Smart Images
Figure CN120864437A_ABST
Abstract
Description
Technical Field
[0001] This application relates to devices including microelectromechanical systems (MEMS) sensors and methods for manufacturing such devices. Background Technology
[0002] Microelectromechanical systems (MEMS) sensors can be formed in materials such as semiconductor materials (e.g., silicon) by selectively fabricating and removing materials. An example of such a MEMS sensor is a pressure sensor, in which a membrane can be formed into a hermetically sealed chamber. Changes in ambient pressure can cause the membrane to deform, which can be detected using, for example, a strain sensor or by capacitively measuring the amount of capacitance between the membrane, which serves as a first and second fixed electrode. Another example of a MEMS sensor is an accelerometer, in which inertial mass is coupled to the membrane of the pressure sensor. Other examples include gas sensors and ultrasonic sensors.
[0003] In some conventional approaches, such MEMS sensors are covered with PFAS (perfluoroalkyl and polyfluoroalkyl substances) gels to provide protection against particles and chemical effects that may cause corrosion, for example.
[0004] However, in recent years, concerns have arisen about the environmental impact of PFAS, and in some jurisdictions, legislation restricting the use of this substance is being implemented or has already been enacted. Summary of the Invention
[0005] According to one embodiment, an apparatus is provided, comprising:
[0006] Substrate element,
[0007] MEMS sensors are provided on this substrate element.
[0008] At least one bonding wire electrically couples the MEMS sensor to the substrate element.
[0009] A protective coating covering the MEMS sensor, at least one bonding wire, and at least a portion of the substrate element, and
[0010] The gel is provided on the protective coating.
[0011] According to another embodiment, a method is provided, comprising:
[0012] Provide substrate components,
[0013] Provide MEMS sensors on substrate components.
[0014] The MEMS sensor is electrically coupled to the substrate element using at least one bonding wire.
[0015] A protective coating is applied to the MEMS sensor, at least one bonding wire, and at least a portion of the substrate element, and...
[0016] Provide gel on the protective coating.
[0017] The above overview is only a brief summary of some embodiments and should not be construed as limiting. Attached Figure Description
[0018] Figure 1 This is a flowchart illustrating a method according to an embodiment.
[0019] Figure 2A-2C The device according to the embodiment is in Figure 1 Schematic cross-sectional views of different stages of the manufacturing process. Detailed Implementation
[0020] Various embodiments will now be described in detail with reference to the accompanying drawings. These embodiments are merely examples and should not be construed as limiting, as other embodiments may include features different from those described above.
[0021] Figure 1 This is a flowchart of a method for manufacturing an apparatus according to an embodiment, and Figure 2A-2C The equipment at different stages of manufacturing is shown. For better illustration, it will be combined with... Figure 1 The methods are described together. Figure 2A-2C .However, Figure 1 The method can also be used to manufacture and Figure 2A-2C The devices shown are different from those shown, and can also be compared with... Figure 2A-2C Different methods of manufacturing Figure 2A-2C The equipment.
[0022] exist Figure 2A-2C In the accompanying drawings, the same reference numerals denote corresponding elements, so these elements will not be described again.
[0023] At point 10, the method includes providing a base element. For example, in... Figure 2A The image shows a substrate element 20. The substrate element may include, for example, a printed circuit board, a lead frame, a pre-molded plastic element, or a ceramic element, but is not limited thereto. In some embodiments, the substrate element includes conductive circuit paths and contact areas for conducting electrical signals, voltages, currents, etc. For example, in... Figure 2A Two circuit paths, 22A and 22B, are shown in the figure.
[0024] In 11, the method includes providing a MEMS sensor on a substrate element. Figure 2AIn the example, a pressure sensor 21 with a membrane-sealed chamber is provided on the substrate element 20. The MEMS sensor 21 can be attached to the substrate element 20 in any conventional manner, such as using glue, soldering, etc. In some embodiments ( Figure 2A (Not shown in the image), the substrate element 20 may include electrical contact elements in the area where the MEMS sensor 21 is mounted, and the MEMS sensor 21 may include corresponding contact elements for establishing electrical contact through mounting.
[0025] At 12 locations, Figure 1 The method involves electrically coupling a MEMS sensor to a substrate element using at least one bonding wire. For example, in Figure 2A The image shows two bonding lines 23A and 23B that couple the MEMS sensor 21 to conductive paths 22A and 22B, respectively.
[0026] For example, bonding lines 23A and 23B can electrically couple the membrane of the MEMS sensor 21 and the anti-electrode of the membrane to a substrate, thereby enabling, for example, capacitance measurements. In other embodiments, strain sensors or any other electrical components of the MEMS sensor 21 may be electrically contacted, for example. In other embodiments, a higher voltage level may be provided than... Figure 2A The two joint lines shown have more or fewer joint lines.
[0027] Additionally, such as Figure 2A As shown, a sidewall element 24 may be provided surrounding the MEMS sensor 21. The sidewall element 24 may be, for example, an annular element made of a non-conductive or conductive material (e.g., a metal coated with a non-conductive material) and may be attached to the substrate element 20 in any conventional manner. In other embodiments, such as if the substrate element 20 is based on a molded plastic element, the sidewall element 24 may be formed integrally with the substrate element 20. As explained later, the sidewall element 24, together with the substrate 20, forms a space for filling the gel therein. However, in other embodiments, the sidewall element 24 may be omitted.
[0028] At location 13, the method involves coating at least a portion of the MEMS sensor, at least one bonding wire, and a substrate element with a protective coating. This is in Figure 2B As shown, coating device 26 provides coating 27 as indicated by arrow 25. Figure 2BIn the example, coating 27 is applied to portions of the MEMS sensor 21, bonding lines 23A, 23B, and substrate element 20 on the inner side of sidewall element 24. Coating 27 includes a material that protects the coated elements (particularly their metallic portions) from corrosion, for example, by protecting them from corrosive or corrosive supporting substances (e.g., chemicals). For example, coating 27 may again provide protection against salt solutions, acid or alkali precipitates, or iodine compositions (which may be contaminants from the tube, for example). For example, the coating may include, but is not limited to, silicon oxide or metal oxides.
[0029] The coating thickness can be selected so that the functionality of the MEMS sensor (e.g., MEMS sensor 21) is not significantly affected. For this purpose, the coating thickness can be less than 100 nm or less than 50 nm (e.g., approximately 30 nm). [The text then abruptly shifts to a different topic:] It can be used to target... Figure 1 The coating at 13 locations and the corresponding targeting Figure 2B Several possible implementations of the coating apparatus 26 in the process.
[0030] One possible approach is plasma deposition using precursors such as hexamethyldisilazane (HMDS) or hexamethyldisiloxane (HMDSO). Conventional deposition techniques using, for example, plasma nozzles can be used to deposit a silicon oxide layer with a thickness of approximately 30 nm using this precursor. Another possible coating method is atomic layer deposition (ALD), where, for example, the surface to be coated is covered with a first reactant, then the first reactant not present on the surface to be coated is removed, and then a second reactant is provided to react with the first reactant to form the desired coating material. In this way, metal oxides, such as alumina, can be used as coating materials, and the thickness can be precisely controlled. Metal oxides can also be hydrolyzed; for example, alumina (Al₂O₃) can be hydrolyzed to Al(OH)₃.
[0031] Back Figure 1 At point 14, the method then includes providing a gel on the reflective coating. This in Figure 2C As shown, where arrow 28 indicates, gel 210 fills the space defined by sidewall element 24 and substrate 20, such that it covers the coating, and thus covers portions of bonding lines 23A, 23B, MEMS sensor 21, and substrate element 20 as shown. Gel dispenser 29 may include, for example, a nozzle or similar element to fill the space enclosed by sidewall element 24 with gel. Without using sidewall element 24, for example, the gel may cover the coating in a dome-shaped form.
[0032] The gel used (e.g., gel 210) can be a fluorine-free gel (e.g., a silicone gel). This silicone provides similar mechanical protection as conventionally used PFAS gels (e.g., preventing particle deposition on sensor 21). Furthermore, silicone-based gels or other fluorine-free gels can provide less corrosion protection compared to conventional PFAS gels. However, in some embodiments, due to the provision of a coating (such as coating 27) protecting specific metal portions, the overall protection provided by the combination of the coating and the fluorine-free gel can be similar to or even superior to the protection provided by a conventional PFAS gel, without the need for such a substance.
[0033] The following examples define some implementation methods:
[0034] Example 1. A device comprising:
[0035] Substrate element,
[0036] MEMS sensors are provided on a substrate element.
[0037] At least one bonding wire electrically couples the MEMS sensor to the substrate element.
[0038] A protective coating covering the MEMS sensor, at least one bonding line, and at least a portion of the substrate element, and
[0039] The gel is provided on the protective coating.
[0040] Example 2. The device of Example 1, wherein the substrate element includes at least one of a printed circuit board, a lead frame, a plastic element, or a ceramic element.
[0041] Example 3. The device of Example 1 or 2 further includes a sidewall element provided on the substrate element and surrounding the MEMS sensor, wherein the gel fills the space defined by the sidewall element and the substrate element.
[0042] Example 4. The device of any one of Examples 1 to 3, wherein the thickness of the protective coating is less than 100 nm.
[0043] Example 5. The device of Example 4, where the thickness is less than 50 nm.
[0044] Example 6. The device of any one of Examples 1 to 5, wherein the coating is configured to protect the MEMS sensor, at least one bonding wire, and at least a portion of the substrate element from corrosive substances.
[0045] Example 7. The device of any one of Examples 1 to 6, wherein the coating comprises at least one of silicon oxide or a metal oxide.
[0046] Example 8. The device of any one of Examples 1 to 7, wherein the gel is a fluorine-free gel.
[0047] Example 9. The device of any one of Examples 1 to 8, wherein the gel comprises a silicone gel.
[0048] Example 10. A device of any one of Examples 1 to 9, wherein at least a portion of the base element includes a contact area or a circuit path.
[0049] Example 11. A device of any of Examples 1 to 10, wherein the MEMS sensor includes a pressure sensor.
[0050] Example 12. A method comprising:
[0051] Provide substrate components,
[0052] Provide MEMS sensors on substrate components.
[0053] The MEMS sensor is electrically coupled to the substrate element using at least one bonding wire.
[0054] A protective coating is applied to the MEMS sensor, at least one bonding wire, and at least a portion of the substrate element, and...
[0055] Provide gel on the protective coating.
[0056] Example 13. The method of Example 12, wherein the coating includes at least one of plasma coating or atomic layer deposition.
[0057] Example 14. The method of Example 12 or 13, wherein the substrate element includes at least one of a printed circuit board, a lead frame, a plastic element, or a ceramic element.
[0058] Example 15. The method of any one of Examples 12 to 14 further includes providing a sidewall element surrounding the MEMS sensor on a substrate element, wherein providing the gel includes filling the space defined by the sidewall element and the substrate element with the gel.
[0059] Example 16. The method of any one of Examples 12 to 15, wherein the thickness of the protective coating is less than 100 nm.
[0060] Example 17. The method of Example 16, where the thickness is less than 50 nm.
[0061] Example 18. The method of any one of Examples 12 to 17, wherein the coating is configured to protect the MEMS sensor, at least one bonding line, and at least a portion of the substrate element from corrosive substances.
[0062] Example 19. The method of any one of Examples 12 to 18, wherein the coating comprises at least one of silicon oxide or a metal oxide.
[0063] Example 20. The method of any one of Examples 12 to 19, wherein the gel is a fluorine-free gel.
[0064] Example 21. The method of any one of Examples 12 to 20, wherein the gel comprises a silicone gel.
[0065] Example 22. The method of any one of Examples 12 to 21, wherein at least a portion of the substrate element includes a contact area or a circuit path.
[0066] Example 23. A method of any one of Examples 12 to 22, wherein the MEMS sensor (21) includes a pressure sensor.
[0067] Although specific embodiments have been illustrated and described herein, those skilled in the art will understand that various alternatives and / or equivalent embodiments can be used to replace the specific embodiments shown and described without departing from the scope of the invention. This application is intended to cover any modifications or variations of the specific embodiments discussed herein. Therefore, the invention is intended to be defined only by the claims and their equivalents.
Claims
1. An apparatus comprising: Substrate element (20), A MEMS sensor (21) is provided on the substrate element (20). At least one bonding wire (23A, 23B) electrically couples the MEMS sensor (21) to the substrate element (20). A protective coating (27) covers at least a portion of the MEMS sensor (21), the at least one bonding line (23A, 23B), and the substrate element (20), and Gel (210) is provided on the protective coating (27).
2. The device according to claim 1, wherein the substrate element (20) comprises at least one of a printed circuit board, a lead frame, a plastic element, or a ceramic element.
3. The device according to claim 1 or 2 further includes a sidewall element (24) provided on the substrate element (20) surrounding the MEMS sensor (21), wherein the gel (27) is filled in the space defined by the sidewall element (24) and the substrate element (20).
4. The device according to any one of claims 1 to 3, wherein the thickness of the protective coating (27) is less than 100 nm.
5. The device according to any one of claims 1 to 4, wherein the coating is configured to protect at least a portion of the MEMS sensor (21), the at least one bonding line (23A, 23B), and the substrate element (20) from corrosive substances.
6. The device according to any one of claims 1 to 5, wherein the coating (27) comprises at least one of silicon oxide or a metal oxide.
7. The device according to any one of claims 1 to 6, wherein the gel (210) is a fluorine-free gel.
8. The device according to any one of claims 1 to 7, wherein the gel (210) comprises a silicone gel.
9. The device according to any one of claims 1 to 8, wherein the at least portion of the substrate element (20) includes a contact area or circuit path (22A, 22B).
10. The device according to any one of claims 1 to 9, wherein the MEMS sensor (21) comprises a pressure sensor.
11. A method comprising: Provides (10) a base element (20), A MEMS sensor (21) is provided (11) on the substrate element (20). The MEMS sensor (21) is electrically coupled (12) to the substrate element (20) using at least one bonding wire (23A, 23B). The MEMS sensor (21), the at least one bonding wire (23A, 23B), and at least a portion of the substrate element (20) are coated (13) with a protective coating (27), and A gel (210) (14) is provided on the protective coating (27).
12. The method of claim 11, wherein coating (13) comprises at least one of plasma coating or atomic layer deposition.
13. The method of claim 11 or 12, further comprising providing a sidewall element (24) surrounding the MEMS sensor (21) on the substrate element (20), wherein providing the gel (210) comprises filling the gel (210) into the space defined by the sidewall element (24) and the substrate element (20).
14. The method according to any one of claims 11 to 13, wherein the thickness of the protective coating (27) is less than 100 nm.
15. The method according to any one of claims 11 to 14, wherein the coating is configured to protect the MEMS sensor (21), the at least one bonding line (23A, 23B), and at least a portion of the substrate element (20) from corrosive substances.
16. The method according to any one of claims 11 to 15, wherein the coating comprises at least one of silicon oxide or a metal oxide.
17. The method according to any one of claims 11 to 16, wherein the gel is a fluorine-free gel.
18. The method according to any one of claims 11 to 17, wherein the gel comprises an organosilicon gel.
19. The method according to any one of claims 11 to 18, wherein the at least portion of the substrate element (20) includes a contact area or circuit path (22A, 22B).
20. The method according to any one of claims 11 to 19, wherein, The MEMS sensor (21) includes a pressure sensor.